From d693b2883c0b9b261d2c490a9933e703359b4542 Mon Sep 17 00:00:00 2001 From: "Frank A. Cancio Bello" Date: Wed, 18 Dec 2019 14:15:53 -0500 Subject: docs: ftrace: Specifies when buffers get clear Clarify a few places where the ring buffer and the "snapshot" buffer are cleared as a side effect of an operation. This will avoid users lost of tracing data because of these so far undocumented behavior. Signed-off-by: Frank A. Cancio Bello Reviewed-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20191218191553.q4lwyxmquvtjzjfz@frank-laptop Signed-off-by: Jonathan Corbet --- Documentation/trace/ftrace.rst | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index d2b5657ed33e..46df39300d22 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -95,7 +95,8 @@ of ftrace. Here is a list of some of the key files: current_tracer: This is used to set or display the current tracer - that is configured. + that is configured. Changing the current tracer clears + the ring buffer content as well as the "snapshot" buffer. available_tracers: @@ -126,7 +127,8 @@ of ftrace. Here is a list of some of the key files: This file holds the output of the trace in a human readable format (described below). Note, tracing is temporarily disabled when the file is open for reading. Once all readers - are closed, tracing is re-enabled. + are closed, tracing is re-enabled. Opening this file for + writing with the O_TRUNC flag clears the ring buffer content. trace_pipe: @@ -490,6 +492,9 @@ of ftrace. Here is a list of some of the key files: # echo global > trace_clock + Setting a clock clears the ring buffer content as well as the + "snapshot" buffer. + trace_marker: This is a very useful file for synchronizing user space -- cgit v1.2.3-59-g8ed1b From ab229d620263e2399c1bd611e64bde5250f72dae Mon Sep 17 00:00:00 2001 From: Konstantin Ryabitsev Date: Mon, 9 Dec 2019 14:26:11 -0500 Subject: Process: provide hardware-security list details Fill in "..." stubs with proper links to the mailing lists's encryption keys and service description URLs. Similarly, fix wording to specify that multiple members of Linux Foundation's IT team have access to internal kernel.org infrastructure, and that all of them have similar confidentiality obligations as the IT team director. Signed-off-by: Konstantin Ryabitsev Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20191209192611.GA1688548@chatter.i7.local Signed-off-by: Jonathan Corbet --- .../process/embargoed-hardware-issues.rst | 23 ++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'Documentation') diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst index 799580acc8de..3d17de7e5aeb 100644 --- a/Documentation/process/embargoed-hardware-issues.rst +++ b/Documentation/process/embargoed-hardware-issues.rst @@ -36,7 +36,10 @@ issue according to our documented process. The list is encrypted and email to the list can be sent by either PGP or S/MIME encrypted and must be signed with the reporter's PGP key or S/MIME certificate. The list's PGP key and S/MIME certificate are available from -https://www.kernel.org/.... +the following URLs: + + - PGP: https://www.kernel.org/static/files/hardware-security.asc + - S/MIME: https://www.kernel.org/static/files/hardware-security.crt While hardware security issues are often handled by the affected hardware vendor, we welcome contact from researchers or individuals who have @@ -55,14 +58,14 @@ Operation of mailing-lists ^^^^^^^^^^^^^^^^^^^^^^^^^^ The encrypted mailing-lists which are used in our process are hosted on -Linux Foundation's IT infrastructure. By providing this service Linux -Foundation's director of IT Infrastructure security technically has the -ability to access the embargoed information, but is obliged to -confidentiality by his employment contract. Linux Foundation's director of -IT Infrastructure security is also responsible for the kernel.org -infrastructure. - -The Linux Foundation's current director of IT Infrastructure security is +Linux Foundation's IT infrastructure. By providing this service, members +of Linux Foundation's IT operations personnel technically have the +ability to access the embargoed information, but are obliged to +confidentiality by their employment contract. Linux Foundation IT +personnel are also responsible for operating and managing the rest of +kernel.org infrastructure. + +The Linux Foundation's current director of IT Project infrastructure is Konstantin Ryabitsev. @@ -274,7 +277,7 @@ software decrypts the email and re-encrypts it individually for each subscriber with the subscriber's PGP key or S/MIME certificate. Details about the mailing-list software and the setup which is used to ensure the security of the lists and protection of the data can be found here: -https://www.kernel.org/.... +https://korg.wiki.kernel.org/userdoc/remail. List keys ^^^^^^^^^ -- cgit v1.2.3-59-g8ed1b From 0854cbdb1829413680cc1bf072dc68254a5ffe7b Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 8 Dec 2019 20:25:10 -0800 Subject: Documentation: x86: fix boot.rst warning and format Fix a Sphinx documentation format warning by breaking a long line into 2 lines. Also drop the ':' usage after the Protocol version numbers since other Protocol versions don't use colons. Documentation/x86/boot.rst:72: WARNING: Malformed table. Text in column margin in table line 57. Fixes: 2c33c27fd603 ("x86/boot: Introduce kernel_info") Fixes: 00cd1c154d56 ("x86/boot: Introduce kernel_info.setup_type_max") Signed-off-by: Randy Dunlap Reviewed-by: Daniel Kiper Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Link: https://lore.kernel.org/r/c6fbf592-0aca-69d9-e903-e869221a041a@infradead.org Signed-off-by: Jonathan Corbet --- Documentation/x86/boot.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst index 90bb8f5ab384..e0dc2ffb7094 100644 --- a/Documentation/x86/boot.rst +++ b/Documentation/x86/boot.rst @@ -69,11 +69,12 @@ Protocol 2.13 (Kernel 3.14) Support 32- and 64-bit flags being set in xloadflags to support booting a 64-bit kernel from 32-bit EFI -Protocol 2.14: BURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c1889 +Protocol 2.14 BURNT BY INCORRECT COMMIT + ae7e1238e68f2a472a125673ab506d49158c1889 (x86/boot: Add ACPI RSDP address to setup_header) DO NOT USE!!! ASSUME SAME AS 2.13. -Protocol 2.15: (Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max. +Protocol 2.15 (Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max. ============= ============================================================ .. note:: -- cgit v1.2.3-59-g8ed1b From eb43135117adc88ba3fd8b15a649c4bceff79962 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 8 Dec 2019 20:16:40 -0800 Subject: Documentation: fix Sphinx warning in xilinx_sdfec.rst Fix Sphinx format warning by adding a blank line. Documentation/misc-devices/xilinx_sdfec.rst:2: WARNING: Explicit markup ends without a blank line; unexpected unindent. Signed-off-by: Randy Dunlap Acked-by: Dragan Cvetic Link: https://lore.kernel.org/r/8d644cf1-fa7b-ec62-84cf-9b41d7c30eed@infradead.org Signed-off-by: Jonathan Corbet --- Documentation/misc-devices/xilinx_sdfec.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/misc-devices/xilinx_sdfec.rst b/Documentation/misc-devices/xilinx_sdfec.rst index 2245fcfa224d..7a47075c171c 100644 --- a/Documentation/misc-devices/xilinx_sdfec.rst +++ b/Documentation/misc-devices/xilinx_sdfec.rst @@ -1,4 +1,5 @@ .. SPDX-License-Identifier: GPL-2.0+ + ==================== Xilinx SD-FEC Driver ==================== -- cgit v1.2.3-59-g8ed1b From 1d5c17e470286b8211e8a18d0f85ae89dec4e8d8 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Tue, 8 Oct 2019 18:06:37 -0700 Subject: RISC-V: Typo fixes in image header and documentation. There are some typos in boot image header and riscv boot documentation. Fix the typos. Signed-off-by: Atish Patra Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20191009010637.9955-1-atish.patra@wdc.com Signed-off-by: Jonathan Corbet --- Documentation/riscv/boot-image-header.rst | 4 ++-- arch/riscv/include/asm/image.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/riscv/boot-image-header.rst b/Documentation/riscv/boot-image-header.rst index 518d46d2389d..d7752533865f 100644 --- a/Documentation/riscv/boot-image-header.rst +++ b/Documentation/riscv/boot-image-header.rst @@ -22,7 +22,7 @@ The following 64-byte header is present in decompressed Linux kernel image:: u64 res2 = 0; /* Reserved */ u64 magic = 0x5643534952; /* Magic number, little endian, "RISCV" */ u32 magic2 = 0x05435352; /* Magic number 2, little endian, "RSC\x05" */ - u32 res4; /* Reserved for PE COFF offset */ + u32 res3; /* Reserved for PE COFF offset */ This header format is compliant with PE/COFF header and largely inspired from ARM64 header. Thus, both ARM64 & RISC-V header can be combined into one common @@ -34,7 +34,7 @@ Notes - This header can also be reused to support EFI stub for RISC-V in future. EFI specification needs PE/COFF image header in the beginning of the kernel image in order to load it as an EFI application. In order to support EFI stub, - code0 should be replaced with "MZ" magic string and res5(at offset 0x3c) should + code0 should be replaced with "MZ" magic string and res3(at offset 0x3c) should point to the rest of the PE/COFF header. - version field indicate header version number diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h index 7b0f92ba0acc..e0b319af3681 100644 --- a/arch/riscv/include/asm/image.h +++ b/arch/riscv/include/asm/image.h @@ -42,7 +42,7 @@ * @res2: reserved * @magic: Magic number (RISC-V specific; deprecated) * @magic2: Magic number 2 (to match the ARM64 'magic' field pos) - * @res4: reserved (will be used for PE COFF offset) + * @res3: reserved (will be used for PE COFF offset) * * The intention is for this header format to be shared between multiple * architectures to avoid a proliferation of image header formats. @@ -59,7 +59,7 @@ struct riscv_image_header { u64 res2; u64 magic; u32 magic2; - u32 res4; + u32 res3; }; #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_IMAGE_H */ -- cgit v1.2.3-59-g8ed1b From a83aaf4979e799705781ceb86a1f29d2b29736b1 Mon Sep 17 00:00:00 2001 From: Madhuparna Bhowmik Date: Wed, 4 Dec 2019 15:49:39 +0530 Subject: Documentation: filesystems: automount-support: Change reference to document autofs.txt to autofs.rst This patch fixes following documentation build warning: Warning: Documentation/filesystems/automount-support.txt references a file that doesn't exist: Documentation/filesystems/autofs.txt Signed-off-by: Madhuparna Bhowmik Link: https://lore.kernel.org/r/20191204101939.6939-1-madhuparnabhowmik04@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/filesystems/automount-support.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/filesystems/automount-support.txt b/Documentation/filesystems/automount-support.txt index b0afd3d55eaf..7d9f82607562 100644 --- a/Documentation/filesystems/automount-support.txt +++ b/Documentation/filesystems/automount-support.txt @@ -9,7 +9,7 @@ also be requested by userspace. IN-KERNEL AUTOMOUNTING ====================== -See section "Mount Traps" of Documentation/filesystems/autofs.txt +See section "Mount Traps" of Documentation/filesystems/autofs.rst Then from userspace, you can just do something like: -- cgit v1.2.3-59-g8ed1b From bc51a6d34c27bd1040fddaf2bdc61309f392f86a Mon Sep 17 00:00:00 2001 From: Madhuparna Bhowmik Date: Wed, 4 Dec 2019 16:15:54 +0530 Subject: Documentation: kernel-hacking: hacking.rst: Change reference to document namespaces.rst to symbol-namespaces.rst This patch fixes the following documentation build warning: Warning: Documentation/kernel-hacking/hacking.rst references a file that doesn't exist: Documentation/kbuild/namespaces.rst According to the following patch: https://patchwork.kernel.org/patch/11178727/ (doc: move namespaces.rst from kbuild/ to core-api/) The file namespaces.rst was moved from kbuild to core-api and renamed to symbol-namespaces.rst. Therefore, this patch changes the reference to the document kbuild/namespaces.rst in hacking.rst to core-api/symbol-namespaces.rst Signed-off-by: Madhuparna Bhowmik Link: https://lore.kernel.org/r/20191204104554.9100-1-madhuparnabhowmik04@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/kernel-hacking/hacking.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kernel-hacking/hacking.rst b/Documentation/kernel-hacking/hacking.rst index a3ddb213a5e1..d62aacb2822a 100644 --- a/Documentation/kernel-hacking/hacking.rst +++ b/Documentation/kernel-hacking/hacking.rst @@ -601,7 +601,7 @@ Defined in ``include/linux/export.h`` This is the variant of `EXPORT_SYMBOL()` that allows specifying a symbol namespace. Symbol Namespaces are documented in -``Documentation/kbuild/namespaces.rst``. +``Documentation/core-api/symbol-namespaces.rst``. :c:func:`EXPORT_SYMBOL_NS_GPL()` -------------------------------- @@ -610,7 +610,7 @@ Defined in ``include/linux/export.h`` This is the variant of `EXPORT_SYMBOL_GPL()` that allows specifying a symbol namespace. Symbol Namespaces are documented in -``Documentation/kbuild/namespaces.rst``. +``Documentation/core-api/symbol-namespaces.rst``. Routines and Conventions ======================== -- cgit v1.2.3-59-g8ed1b From 3dbbeef42b6489ec7c10dba4d2b7805c9bbff773 Mon Sep 17 00:00:00 2001 From: Federico Vaga Date: Sun, 1 Dec 2019 13:19:41 +0100 Subject: doc:locking: fix locktorture parameter description The description was talking about two default values: I removed the wrong one. Signed-off-by: Federico Vaga Link: https://lore.kernel.org/r/20191201121941.6971-1-federico.vaga@vaga.pv.it Signed-off-by: Jonathan Corbet --- Documentation/locking/locktorture.rst | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/locking/locktorture.rst b/Documentation/locking/locktorture.rst index e79eeeca3ac6..5bcb99ba7bd9 100644 --- a/Documentation/locking/locktorture.rst +++ b/Documentation/locking/locktorture.rst @@ -103,8 +103,7 @@ stat_interval Number of seconds between statistics-related printk()s. By default, locktorture will report stats every 60 seconds. Setting the interval to zero causes the statistics to - be printed -only- when the module is unloaded, and this - is the default. + be printed -only- when the module is unloaded. stutter The length of time to run the test before pausing for this -- cgit v1.2.3-59-g8ed1b From c1ccff45e54eb54fa4e437da197e6738b002f22d Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 29 Nov 2019 19:28:23 +0100 Subject: docs/memory-barriers.txt.kokr: Minor wordsmith MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As suggested by Paul, I got a review from another Korean hacker Yunjae.  From the review, I got not only 'Reviewed-by:' tags, but also found a few minor nits.  So I made a second version of the patchset but just realized that the first version has already sent to Linus.  I therefore send only the nit fixes as another patch. ----------------------------- >8 ---------------------------------------- docs/memory-barriers.txt.kokr: Minor wordsmith This commit fixes a couple of minor nits in the Korean translation of 'memory-barriers.txt'. Signed-off-by: SeongJae Park Reviewed-by: Yunjae Lee Link: https://lore.kernel.org/r/20191129182823.8710-1-sjpark@amazon.de Signed-off-by: Jonathan Corbet --- Documentation/translations/ko_KR/memory-barriers.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/translations/ko_KR/memory-barriers.txt b/Documentation/translations/ko_KR/memory-barriers.txt index f07c40a068b5..2e831ece6e26 100644 --- a/Documentation/translations/ko_KR/memory-barriers.txt +++ b/Documentation/translations/ko_KR/memory-barriers.txt @@ -2413,7 +2413,7 @@ _않습니다_. 알고 있는, - inb() 나 writel() 과 같은 - 적절한 액세스 루틴을 통해 이루어져야만 합니다. 이것들은 대부분의 경우에는 명시적 메모리 배리어 와 함께 사용될 필요가 없습니다만, 완화된 메모리 액세스 속성으로 I/O 메모리 윈도우로의 참조를 위해 -액세스 함수가 사용된다면 순서를 강제하기 위해 _madatory_ 메모리 배리어가 +액세스 함수가 사용된다면 순서를 강제하기 위해 _mandatory_ 메모리 배리어가 필요합니다. 더 많은 정보를 위해선 Documentation/driver-api/device-io.rst 를 참고하십시오. @@ -2528,7 +2528,7 @@ I/O 액세스를 통한 주변장치와의 통신은 아키텍쳐와 기기에 이것들은 readX() 와 writeX() 랑 비슷하지만, 더 완화된 메모리 순서 보장을 제공합니다. 구체적으로, 이것들은 일반적 메모리 액세스나 delay() 루프 (예:앞의 2-5 항목) 에 대해 순서를 보장하지 않습니다만 디폴트 I/O - 기능으로 매핑된 __iomem 포인터에 대해 동작할 때, 같은 CPU 쓰레드에 의해 + 기능으로 매핑된 __iomem 포인터에 대해 동작할 때, 같은 CPU 쓰레드에 의한 같은 주변장치로의 액세스에는 순서가 맞춰질 것이 보장됩니다. (*) readsX(), writesX(): -- cgit v1.2.3-59-g8ed1b From 7c737c64b0ff08c7427007c239922df7aef2748e Mon Sep 17 00:00:00 2001 From: Masanari Iida Date: Fri, 27 Dec 2019 01:21:38 +0900 Subject: Doc: x86: Fix a typo in mm.rst Fix a spelling typo in mm.rst. Signed-off-by: Masanari Iida Link: https://lore.kernel.org/r/20191226162138.17601-1-standby24x7@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/x86/x86_64/mm.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/x86/x86_64/mm.rst b/Documentation/x86/x86_64/mm.rst index 267fc4808945..e5053404a1ae 100644 --- a/Documentation/x86/x86_64/mm.rst +++ b/Documentation/x86/x86_64/mm.rst @@ -1,8 +1,8 @@ .. SPDX-License-Identifier: GPL-2.0 -================ -Memory Managment -================ +================= +Memory Management +================= Complete virtual memory map with 4-level page tables ==================================================== -- cgit v1.2.3-59-g8ed1b From 6c23821c19305d9f9e3166492483425845b84f3a Mon Sep 17 00:00:00 2001 From: Masanari Iida Date: Thu, 26 Dec 2019 01:55:34 +0900 Subject: docs: w1: Fix a typo in omap-hdq.rst Fix a spelling typo in omap-hdq.rst Signed-off-by: Masanari Iida Link: https://lore.kernel.org/r/20191225165534.9395-1-standby24x7@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/w1/masters/omap-hdq.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/w1/masters/omap-hdq.rst b/Documentation/w1/masters/omap-hdq.rst index 345298a59e50..5347b5d9e90a 100644 --- a/Documentation/w1/masters/omap-hdq.rst +++ b/Documentation/w1/masters/omap-hdq.rst @@ -44,7 +44,7 @@ that the ID used should be same for both master and slave driver loading. e.g:: insmod omap_hdq.ko W1_ID=2 - inamod w1_bq27000.ko F_ID=2 + insmod w1_bq27000.ko F_ID=2 The driver also supports 1-wire mode. In this mode, there is no need to pass slave ID as parameter. The driver will auto-detect slaves connected -- cgit v1.2.3-59-g8ed1b From dec6224bb9d6fde8058b02ac441fbfbf5c224aa0 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Fri, 20 Dec 2019 11:04:43 +0800 Subject: docs/zh_CN: add Chinese version of embargoed hardware issues Embargoed hardware issues is a necessary process guide, but leak of Chinese version, since there is more Chinese hardware vendors in market. We'd better have a Chinese version of this guide. This patch translate the guide, add it into toctree. and also add a link stub for the original doc. Signed-off-by: Alex Shi Cc: Fengguang Wu Cc: lizefan@huawei.com Cc: Jonathan Corbet Cc: Harry Wei Cc: Greg Kroah-Hartman Cc: Sasha Levin Cc: Dave Hansen Cc: Thomas Gleixner Cc: Ben Hutchings Cc: Tom Lendacky Cc: Tony Luck Cc: Kees Cook Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1576811085-30544-1-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Jonathan Corbet --- .../process/embargoed-hardware-issues.rst | 2 + .../zh_CN/process/embargoed-hardware-issues.rst | 228 +++++++++++++++++++++ Documentation/translations/zh_CN/process/index.rst | 1 + 3 files changed, 231 insertions(+) create mode 100644 Documentation/translations/zh_CN/process/embargoed-hardware-issues.rst (limited to 'Documentation') diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst index 3d17de7e5aeb..3bc44a7932ee 100644 --- a/Documentation/process/embargoed-hardware-issues.rst +++ b/Documentation/process/embargoed-hardware-issues.rst @@ -1,3 +1,5 @@ +.. _embargoed_hardware_issues: + Embargoed hardware issues ========================= diff --git a/Documentation/translations/zh_CN/process/embargoed-hardware-issues.rst b/Documentation/translations/zh_CN/process/embargoed-hardware-issues.rst new file mode 100644 index 000000000000..b93f1af68261 --- /dev/null +++ b/Documentation/translations/zh_CN/process/embargoed-hardware-issues.rst @@ -0,0 +1,228 @@ +.. include:: ../disclaimer-zh_CN.rst + +:Original: :ref:`Documentation/process/embargoed-hardware-issues.rst ` +:Translator: Alex Shi + +被限制的硬件问题 +================ + +范围 +---- + +导致安全问题的硬件问题与只影响Linux内核的纯软件错误是不同的安全错误类别。 + +必须区别对待诸如熔毁(Meltdown)、Spectre、L1TF等硬件问题，因为它们通常会影响 +所有操作系统（“OS”），因此需要在不同的OS供应商、发行版、硬件供应商和其他各方 +之间进行协调。对于某些问题，软件缓解可能依赖于微码或固件更新，这需要进一步的 +协调。 + +.. _zh_Contact: + +接触 +---- + +Linux内核硬件安全小组独立于普通的Linux内核安全小组。 + +该小组只负责协调被限制的硬件安全问题。Linux内核中纯软件安全漏洞的报告不由该 +小组处理，报告者将被引导至常规Linux内核安全小组(:ref:`Documentation/admin-guide/ +`)联系。 + +可以通过电子邮件 与小组联系。这是一份私密的安全 +官名单，他们将帮助您根据我们的文档化流程协调问题。 + +邮件列表是加密的，发送到列表的电子邮件可以通过PGP或S/MIME加密，并且必须使用报告 +者的PGP密钥或S/MIME证书签名。该列表的PGP密钥和S/MIME证书可从 +https://www.kernel.org/.... 获得。 + +虽然硬件安全问题通常由受影响的硬件供应商处理，但我们欢迎发现潜在硬件缺陷的研究 +人员或个人与我们联系。 + +硬件安全官 +^^^^^^^^^^ + +目前的硬件安全官小组: + + - Linus Torvalds（Linux基金会院士） + - Greg Kroah Hartman（Linux基金会院士） + - Thomas Gleixner（Linux基金会院士） + +邮件列表的操作 +^^^^^^^^^^^^^^ + +处理流程中使用的加密邮件列表托管在Linux Foundation的IT基础设施上。通过提供这项 +服务，Linux基金会的IT基础设施安全总监在技术上有能力访问被限制的信息，但根据他 +的雇佣合同，他必须保密。Linux基金会的IT基础设施安全总监还负责 kernel.org 基础 +设施。 + +Linux基金会目前的IT基础设施安全总监是 Konstantin Ryabitsev。 + +保密协议 +-------- + +Linux内核硬件安全小组不是正式的机构，因此无法签订任何保密协议。核心社区意识到 +这些问题的敏感性，并提供了一份谅解备忘录。 + +谅解备忘录 +---------- + +Linux内核社区深刻理解在不同操作系统供应商、发行商、硬件供应商和其他各方之间 +进行协调时，保持硬件安全问题处于限制状态的要求。 + +Linux内核社区在过去已经成功地处理了硬件安全问题，并且有必要的机制允许在限制 +限制下进行符合社区的开发。 + +Linux内核社区有一个专门的硬件安全小组负责初始联系，并监督在限制规则下处理 +此类问题的过程。 + +硬件安全小组确定开发人员（领域专家），他们将组成特定问题的初始响应小组。最初 +的响应小组可以引入更多的开发人员（领域专家）以最佳的技术方式解决这个问题。 + +所有相关开发商承诺遵守限制规定，并对收到的信息保密。违反承诺将导致立即从当前 +问题中排除，并从所有相关邮件列表中删除。此外，硬件安全小组还将把违反者排除在 +未来的问题之外。这一后果的影响在我们社区是一种非常有效的威慑。如果发生违规 +情况，硬件安全小组将立即通知相关方。如果您或任何人发现潜在的违规行为，请立即 +向硬件安全人员报告。 + +流程 +^^^^ + +由于Linux内核开发的全球分布式特性，面对面的会议几乎不可能解决硬件安全问题。 +由于时区和其他因素，电话会议很难协调，只能在绝对必要时使用。加密电子邮件已被 +证明是解决此类问题的最有效和最安全的通信方法。 + +开始披露 +"""""""" + +披露内容首先通过电子邮件联系Linux内核硬件安全小组。此初始联系人应包含问题的 +描述和任何已知受影响硬件的列表。如果您的组织制造或分发受影响的硬件，我们建议 +您也考虑哪些其他硬件可能会受到影响。 + +硬件安全小组将提供一个特定于事件的加密邮件列表，用于与报告者进行初步讨论、 +进一步披露和协调。 + +硬件安全小组将向披露方提供一份开发人员（领域专家）名单，在与开发人员确认他们 +将遵守本谅解备忘录和文件化流程后，应首先告知开发人员有关该问题的信息。这些开发 +人员组成初始响应小组，并在初始接触后负责处理问题。硬件安全小组支持响应小组， +但不一定参与缓解开发过程。 + +虽然个别开发人员可能通过其雇主受到保密协议的保护，但他们不能以Linux内核开发 +人员的身份签订个别保密协议。但是，他们将同意遵守这一书面程序和谅解备忘录。 + +披露方应提供已经或应该被告知该问题的所有其他实体的联系人名单。这有几个目的: + + - 披露的实体列表允许跨行业通信，例如其他操作系统供应商、硬件供应商等。 + + - 可联系已披露的实体，指定应参与缓解措施开发的专家。 + + - 如果需要处理某一问题的专家受雇于某一上市实体或某一上市实体的成员，则响应 + 小组可要求该实体披露该专家。这确保专家也是实体反应小组的一部分。 + +披露 +"""" + +披露方通过特定的加密邮件列表向初始响应小组提供详细信息。 + +根据我们的经验，这些问题的技术文档通常是一个足够的起点，最好通过电子邮件进行 +进一步的技术澄清。 + +缓解开发 +"""""""" + +初始响应小组设置加密邮件列表，或在适当的情况下重新修改现有邮件列表。 + +使用邮件列表接近于正常的Linux开发过程，并且在过去已经成功地用于为各种硬件安全 +问题开发缓解措施。 + +邮件列表的操作方式与正常的Linux开发相同。发布、讨论和审查修补程序，如果同意， +则应用于非公共git存储库，参与开发人员只能通过安全连接访问该存储库。存储库包含 +针对主线内核的主开发分支，并根据需要为稳定的内核版本提供向后移植分支。 + +最初的响应小组将根据需要从Linux内核开发人员社区中确定更多的专家。引进专家可以 +在开发过程中的任何时候发生，需要及时处理。 + +如果专家受雇于披露方提供的披露清单上的实体或其成员，则相关实体将要求其参与。 + +否则，披露方将被告知专家参与的情况。谅解备忘录涵盖了专家，要求披露方确认参与。 +如果披露方有令人信服的理由提出异议，则必须在五个工作日内提出异议，并立即与事件 +小组解决。如果披露方在五个工作日内未作出回应，则视为默许。 + +在确认或解决异议后，专家由事件小组披露，并进入开发过程。 + +协调发布 +"""""""" + +有关各方将协商限制结束的日期和时间。此时，准备好的缓解措施集成到相关的内核树中 +并发布。 + +虽然我们理解硬件安全问题需要协调限制时间，但限制时间应限制在所有有关各方制定、 +测试和准备缓解措施所需的最短时间内。人为地延长限制时间以满足会议讨论日期或其他 +非技术原因，会给相关的开发人员和响应小组带来了更多的工作和负担，因为补丁需要 +保持最新，以便跟踪正在进行的上游内核开发，这可能会造成冲突的更改。 + +CVE分配 +""""""" + +硬件安全小组和初始响应小组都不分配CVE，开发过程也不需要CVE。如果CVE是由披露方 +提供的，则可用于文档中。 + +流程专使 +-------- + +为了协助这一进程，我们在各组织设立了专使，他们可以回答有关报告流程和进一步处理 +的问题或提供指导。专使不参与特定问题的披露，除非响应小组或相关披露方提出要求。 +现任专使名单: + + ============= ======================================================== + ARM + AMD Tom Lendacky + IBM + Intel Tony Luck + Qualcomm Trilok Soni + + Microsoft Sasha Levin + VMware + Xen Andrew Cooper + + Canonical Tyler Hicks + Debian Ben Hutchings + Oracle Konrad Rzeszutek Wilk + Red Hat Josh Poimboeuf + SUSE Jiri Kosina + + Amazon + Google Kees Cook + ============= ======================================================== + +如果要将您的组织添加到专使名单中，请与硬件安全小组联系。被提名的专使必须完全 +理解和支持我们的过程，并且在Linux内核社区中很容易联系。 + +加密邮件列表 +------------ + +我们使用加密邮件列表进行通信。这些列表的工作原理是，发送到列表的电子邮件使用 +列表的PGP密钥或列表的/MIME证书进行加密。邮件列表软件对电子邮件进行解密，并 +使用订阅者的PGP密钥或S/MIME证书为每个订阅者分别对其进行重新加密。有关邮件列表 +软件和用于确保列表安全和数据保护的设置的详细信息，请访问: +https://www.kernel.org/.... + +关键点 +^^^^^^ + +初次接触见 :ref:`zh_Contact`. 对于特定于事件的邮件列表，密钥和S/MIME证书通过 +特定列表发送的电子邮件传递给订阅者。 + +订阅事件特定列表 +^^^^^^^^^^^^^^^^ + +订阅由响应小组处理。希望参与通信的披露方将潜在订户的列表发送给响应组，以便 +响应组可以验证订阅请求。 + +每个订户都需要通过电子邮件向响应小组发送订阅请求。电子邮件必须使用订阅服务器 +的PGP密钥或S/MIME证书签名。如果使用PGP密钥，则必须从公钥服务器获得该密钥， +并且理想情况下该密钥连接到Linux内核的PGP信任网。另请参见: +https://www.kernel.org/signature.html. + +响应小组验证订阅者，并将订阅者添加到列表中。订阅后，订阅者将收到来自邮件列表 +的电子邮件，该邮件列表使用列表的PGP密钥或列表的/MIME证书签名。订阅者的电子邮件 +客户端可以从签名中提取PGP密钥或S/MIME证书，以便订阅者可以向列表发送加密电子 +邮件。 diff --git a/Documentation/translations/zh_CN/process/index.rst b/Documentation/translations/zh_CN/process/index.rst index be1e764a80d2..f7a84eff6e93 100644 --- a/Documentation/translations/zh_CN/process/index.rst +++ b/Documentation/translations/zh_CN/process/index.rst @@ -43,6 +43,7 @@ stable-api-nonsense stable-kernel-rules management-style + embargoed-hardware-issues 这些是一些总体技术指南，由于缺乏更好的地方，现在已经放在这里 -- cgit v1.2.3-59-g8ed1b From fdfb5dfa747fb58976d18af9fb20bec8981f6564 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Fri, 20 Dec 2019 11:04:44 +0800 Subject: docs/zh_CN: translate kernel driver statement into Chinese kernel driver statement is a great statement in kernel community. This patch translate the statement into Chinese and add it into toctree. Signed-off-by: Alex Shi Cc: Harry Wei Cc: lizefan@huawei.com Cc: Fengguang Wu Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1576811085-30544-2-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Jonathan Corbet --- Documentation/translations/zh_CN/process/index.rst | 1 + .../zh_CN/process/kernel-driver-statement.rst | 199 +++++++++++++++++++++ 2 files changed, 200 insertions(+) create mode 100644 Documentation/translations/zh_CN/process/kernel-driver-statement.rst (limited to 'Documentation') diff --git a/Documentation/translations/zh_CN/process/index.rst b/Documentation/translations/zh_CN/process/index.rst index f7a84eff6e93..47a2af54fb13 100644 --- a/Documentation/translations/zh_CN/process/index.rst +++ b/Documentation/translations/zh_CN/process/index.rst @@ -31,6 +31,7 @@ development-process email-clients license-rules + kernel-driver-statement 其它大多数开发人员感兴趣的社区指南： diff --git a/Documentation/translations/zh_CN/process/kernel-driver-statement.rst b/Documentation/translations/zh_CN/process/kernel-driver-statement.rst new file mode 100644 index 000000000000..2b3375bcccfd --- /dev/null +++ b/Documentation/translations/zh_CN/process/kernel-driver-statement.rst @@ -0,0 +1,199 @@ +.. _cn_process_statement_driver: + +.. include:: ../disclaimer-zh_CN.rst + +:Original: :ref:`Documentation/process/kernel-driver-statement.rst ` +:Translator: Alex Shi + +内核驱动声明 +------------ + +关于Linux内核模块的立场声明 +=========================== + +我们，以下署名的Linux内核开发人员，认为任何封闭源Linux内核模块或驱动程序都是 +有害的和不可取的。我们已经一再发现它们对Linux用户，企业和更大的Linux生态系统 +有害。这样的模块否定了Linux开发模型的开放性，稳定性，灵活性和可维护性，并使 +他们的用户无法使用Linux社区的专业知识。提供闭源内核模块的供应商迫使其客户 +放弃Linux的主要优势或选择新的供应商。因此，为了充分利用开源所提供的成本节省和 +共享支持优势，我们敦促供应商采取措施，以开源内核代码在Linux上为其客户提供支持。 + +我们只为自己说话，而不是我们今天可能会为之工作，过去或将来会为之工作的任何公司。 + + - Dave Airlie + - Nick Andrew + - Jens Axboe + - Ralf Baechle + - Felipe Balbi + - Ohad Ben-Cohen + - Muli Ben-Yehuda + - Jiri Benc + - Arnd Bergmann + - Thomas Bogendoerfer + - Vitaly Bordug + - James Bottomley + - Josh Boyer + - Neil Brown + - Mark Brown + - David Brownell + - Michael Buesch + - Franck Bui-Huu + - Adrian Bunk + - François Cami + - Ralph Campbell + - Luiz Fernando N. Capitulino + - Mauro Carvalho Chehab + - Denis Cheng + - Jonathan Corbet + - Glauber Costa + - Alan Cox + - Magnus Damm + - Ahmed S. Darwish + - Robert P. J. Day + - Hans de Goede + - Arnaldo Carvalho de Melo + - Helge Deller + - Jean Delvare + - Mathieu Desnoyers + - Sven-Thorsten Dietrich + - Alexey Dobriyan + - Daniel Drake + - Alex Dubov + - Randy Dunlap + - Michael Ellerman + - Pekka Enberg + - Jan Engelhardt + - Mark Fasheh + - J. Bruce Fields + - Larry Finger + - Jeremy Fitzhardinge + - Mike Frysinger + - Kumar Gala + - Robin Getz + - Liam Girdwood + - Jan-Benedict Glaw + - Thomas Gleixner + - Brice Goglin + - Cyrill Gorcunov + - Andy Gospodarek + - Thomas Graf + - Krzysztof Halasa + - Harvey Harrison + - Stephen Hemminger + - Michael Hennerich + - Tejun Heo + - Benjamin Herrenschmidt + - Kristian Høgsberg + - Henrique de Moraes Holschuh + - Marcel Holtmann + - Mike Isely + - Takashi Iwai + - Olof Johansson + - Dave Jones + - Jesper Juhl + - Matthias Kaehlcke + - Kenji Kaneshige + - Jan Kara + - Jeremy Kerr + - Russell King + - Olaf Kirch + - Roel Kluin + - Hans-Jürgen Koch + - Auke Kok + - Peter Korsgaard + - Jiri Kosina + - Aaro Koskinen + - Mariusz Kozlowski + - Greg Kroah-Hartman + - Michael Krufky + - Aneesh Kumar + - Clemens Ladisch + - Christoph Lameter + - Gunnar Larisch + - Anders Larsen + - Grant Likely + - John W. Linville + - Yinghai Lu + - Tony Luck + - Pavel Machek + - Matt Mackall + - Paul Mackerras + - Roland McGrath + - Patrick McHardy + - Kyle McMartin + - Paul Menage + - Thierry Merle + - Eric Miao + - Akinobu Mita + - Ingo Molnar + - James Morris + - Andrew Morton + - Paul Mundt + - Oleg Nesterov + - Luca Olivetti + - S.Çağlar Onur + - Pierre Ossman + - Keith Owens + - Venkatesh Pallipadi + - Nick Piggin + - Nicolas Pitre + - Evgeniy Polyakov + - Richard Purdie + - Mike Rapoport + - Sam Ravnborg + - Gerrit Renker + - Stefan Richter + - David Rientjes + - Luis R. Rodriguez + - Stefan Roese + - Francois Romieu + - Rami Rosen + - Stephen Rothwell + - Maciej W. Rozycki + - Mark Salyzyn + - Yoshinori Sato + - Deepak Saxena + - Holger Schurig + - Amit Shah + - Yoshihiro Shimoda + - Sergei Shtylyov + - Kay Sievers + - Sebastian Siewior + - Rik Snel + - Jes Sorensen + - Alexey Starikovskiy + - Alan Stern + - Timur Tabi + - Hirokazu Takata + - Eliezer Tamir + - Eugene Teo + - Doug Thompson + - FUJITA Tomonori + - Dmitry Torokhov + - Marcelo Tosatti + - Steven Toth + - Theodore Tso + - Matthias Urlichs + - Geert Uytterhoeven + - Arjan van de Ven + - Ivo van Doorn + - Rik van Riel + - Wim Van Sebroeck + - Hans Verkuil + - Horst H. von Brand + - Dmitri Vorobiev + - Anton Vorontsov + - Daniel Walker + - Johannes Weiner + - Harald Welte + - Matthew Wilcox + - Dan J. Williams + - Darrick J. Wong + - David Woodhouse + - Chris Wright + - Bryan Wu + - Rafael J. Wysocki + - Herbert Xu + - Vlad Yasevich + - Peter Zijlstra + - Bartlomiej Zolnierkiewicz -- cgit v1.2.3-59-g8ed1b From 3697aa15563f3bb06c27af135dd7be77af4fe71a Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Fri, 20 Dec 2019 11:04:45 +0800 Subject: docs/zh_CN: translate kernel enforcement statement kernel enforcement statement is a important statement to show a kind of attitude in kernel community. This patch translate it into Chinese and add it into toctree. Signed-off-by: Alex Shi Cc: Fengguang Wu Cc: Li Zefan Cc: Harry Wei Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1576811085-30544-3-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Jonathan Corbet --- Documentation/translations/zh_CN/process/index.rst | 1 + .../zh_CN/process/kernel-enforcement-statement.rst | 151 +++++++++++++++++++++ 2 files changed, 152 insertions(+) create mode 100644 Documentation/translations/zh_CN/process/kernel-enforcement-statement.rst (limited to 'Documentation') diff --git a/Documentation/translations/zh_CN/process/index.rst b/Documentation/translations/zh_CN/process/index.rst index 47a2af54fb13..8051a7b322c5 100644 --- a/Documentation/translations/zh_CN/process/index.rst +++ b/Documentation/translations/zh_CN/process/index.rst @@ -31,6 +31,7 @@ development-process email-clients license-rules + kernel-enforcement-statement kernel-driver-statement 其它大多数开发人员感兴趣的社区指南： diff --git a/Documentation/translations/zh_CN/process/kernel-enforcement-statement.rst b/Documentation/translations/zh_CN/process/kernel-enforcement-statement.rst new file mode 100644 index 000000000000..75f7b7b9137c --- /dev/null +++ b/Documentation/translations/zh_CN/process/kernel-enforcement-statement.rst @@ -0,0 +1,151 @@ +.. _cn_process_statement_kernel: + +.. include:: ../disclaimer-zh_CN.rst + +:Original: :ref:`Documentation/process/kernel-enforcement-statement.rst ` +:Translator: Alex Shi + +Linux 内核执行声明 +------------------ + +作为Linux内核的开发人员，我们对如何使用我们的软件以及如何实施软件许可证有着 +浓厚的兴趣。遵守GPL-2.0的互惠共享义务对我们软件和社区的长期可持续性至关重要。 + +虽然有权强制执行对我们社区的贡献中的单独版权权益，但我们有共同的利益，即确保 +个人强制执行行动的方式有利于我们的社区，不会对我们软件生态系统的健康和增长 +产生意外的负面影响。为了阻止无益的执法行动，我们同意代表我们自己和我们版权 +利益的任何继承人对Linux内核用户作出以下符合我们开发社区最大利益的承诺: + + 尽管有GPL-2.0的终止条款，我们同意，采用以下GPL-3.0条款作为我们许可证下的 + 附加许可，作为任何对许可证下权利的非防御性主张，这符合我们开发社区的最佳 + 利益。 + + 但是，如果您停止所有违反本许可证的行为，则您从特定版权持有人处获得的 + 许可证将被恢复：（a）暂时恢复，除非版权持有人明确并最终终止您的许可证； + 以及（b）永久恢复, 如果版权持有人未能在你终止违反后60天内以合理方式 + 通知您违反本许可证的行为，则永久恢复您的许可证。 + + 此外，如果版权所有者以某种合理的方式通知您违反了本许可，这是您第一次 + 从该版权所有者处收到违反本许可的通知（对于任何作品），并且您在收到通知 + 后的30天内纠正违规行为。则您从特定版权所有者处获得的许可将永久恢复. + +我们提供这些保证的目的是鼓励更多地使用该软件。我们希望公司和个人使用、修改和 +分发此软件。我们希望以公开和透明的方式与用户合作，以消除我们对法规遵从性或强制 +执行的任何不确定性，这些不确定性可能会限制我们软件的采用。我们将法律行动视为 +最后手段，只有在其他社区努力未能解决这一问题时才采取行动。 + +最后，一旦一个不合规问题得到解决，我们希望用户会感到欢迎，加入我们为之努力的 +这个项目。共同努力，我们会更强大。 + +除了下面提到的以外，我们只为自己说话，而不是为今天、过去或将来可能为之工作的 +任何公司说话。 + + - Laura Abbott + - Bjorn Andersson (Linaro) + - Andrea Arcangeli + - Neil Armstrong + - Jens Axboe + - Pablo Neira Ayuso + - Khalid Aziz + - Ralf Baechle + - Felipe Balbi + - Arnd Bergmann + - Ard Biesheuvel + - Tim Bird + - Paolo Bonzini + - Christian Borntraeger + - Mark Brown (Linaro) + - Paul Burton + - Javier Martinez Canillas + - Rob Clark + - Kees Cook (Google) + - Jonathan Corbet + - Dennis Dalessandro + - Vivien Didelot (Savoir-faire Linux) + - Hans de Goede + - Mel Gorman (SUSE) + - Sven Eckelmann + - Alex Elder (Linaro) + - Fabio Estevam + - Larry Finger + - Bhumika Goyal + - Andy Gross + - Juergen Gross + - Shawn Guo + - Ulf Hansson + - Stephen Hemminger (Microsoft) + - Tejun Heo + - Rob Herring + - Masami Hiramatsu + - Michal Hocko + - Simon Horman + - Johan Hovold (Hovold Consulting AB) + - Christophe JAILLET + - Olof Johansson + - Lee Jones (Linaro) + - Heiner Kallweit + - Srinivas Kandagatla + - Jan Kara + - Shuah Khan (Samsung) + - David Kershner + - Jaegeuk Kim + - Namhyung Kim + - Colin Ian King + - Jeff Kirsher + - Greg Kroah-Hartman (Linux Foundation) + - Christian König + - Vinod Koul + - Krzysztof Kozlowski + - Viresh Kumar + - Aneesh Kumar K.V + - Julia Lawall + - Doug Ledford + - Chuck Lever (Oracle) + - Daniel Lezcano + - Shaohua Li + - Xin Long + - Tony Luck + - Catalin Marinas (Arm Ltd) + - Mike Marshall + - Chris Mason + - Paul E. McKenney + - Arnaldo Carvalho de Melo + - David S. Miller + - Ingo Molnar + - Kuninori Morimoto + - Trond Myklebust + - Martin K. Petersen (Oracle) + - Borislav Petkov + - Jiri Pirko + - Josh Poimboeuf + - Sebastian Reichel (Collabora) + - Guenter Roeck + - Joerg Roedel + - Leon Romanovsky + - Steven Rostedt (VMware) + - Frank Rowand + - Ivan Safonov + - Anna Schumaker + - Jes Sorensen + - K.Y. Srinivasan + - David Sterba (SUSE) + - Heiko Stuebner + - Jiri Kosina (SUSE) + - Willy Tarreau + - Dmitry Torokhov + - Linus Torvalds + - Thierry Reding + - Rik van Riel + - Luis R. Rodriguez + - Geert Uytterhoeven (Glider bvba) + - Eduardo Valentin (Amazon.com) + - Daniel Vetter + - Linus Walleij + - Richard Weinberger + - Dan Williams + - Rafael J. Wysocki + - Arvind Yadav + - Masahiro Yamada + - Wei Yongjun + - Lv Zheng + - Marc Zyngier (Arm Ltd) -- cgit v1.2.3-59-g8ed1b From 19a602b745a2cbae553f6d45885eb01f2b28ff48 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Fri, 10 Jan 2020 10:04:27 +0000 Subject: devices.txt: fix spelling mistake: "shapshot" -> "snapshot" Fix spelling mistake in text. Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20200110100427.236530-1-colin.king@canonical.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/devices.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt index 1c5d2281efc9..2a97aaec8b12 100644 --- a/Documentation/admin-guide/devices.txt +++ b/Documentation/admin-guide/devices.txt @@ -319,7 +319,7 @@ 182 = /dev/perfctr Performance-monitoring counters 183 = /dev/hwrng Generic random number generator 184 = /dev/cpu/microcode CPU microcode update interface - 186 = /dev/atomicps Atomic shapshot of process state data + 186 = /dev/atomicps Atomic snapshot of process state data 187 = /dev/irnet IrNET device 188 = /dev/smbusbios SMBus BIOS 189 = /dev/ussp_ctl User space serial port control -- cgit v1.2.3-59-g8ed1b From 6f7f8ef713a24ccea341a7f0cb92ef2b6b297f01 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Mon, 6 Jan 2020 11:37:35 +0100 Subject: docs: block/biovecs: update the location of bio.c Replace fs with block since bio.c had been moved to block folder. Signed-off-by: Guoqing Jiang Link: https://lore.kernel.org/r/20200106103735.10327-1-guoqing.jiang@cloud.ionos.com Signed-off-by: Jonathan Corbet --- Documentation/block/biovecs.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/block/biovecs.rst b/Documentation/block/biovecs.rst index 86fa66c87172..ad303a2569d3 100644 --- a/Documentation/block/biovecs.rst +++ b/Documentation/block/biovecs.rst @@ -47,7 +47,7 @@ Having a real iterator, and making biovecs immutable, has a number of advantages: * Before, iterating over bios was very awkward when you weren't processing - exactly one bvec at a time - for example, bio_copy_data() in fs/bio.c, + exactly one bvec at a time - for example, bio_copy_data() in block/bio.c, which copies the contents of one bio into another. Because the biovecs wouldn't necessarily be the same size, the old code was tricky convoluted - it had to walk two different bios at the same time, keeping both bi_idx and -- cgit v1.2.3-59-g8ed1b From a65d634e63644d05a22f32e5f2e56dde4f7ee77b Mon Sep 17 00:00:00 2001 From: "Frank A. Cancio Bello" Date: Tue, 24 Dec 2019 19:06:05 -0500 Subject: docs: ftrace: Clarify the RAM impact of buffer_size_kb The current text could mislead the user into believing that the number of pages allocated by each CPU ring buffer is calculated by the round up of the division: buffer_size_kb / PAGE_SIZE. Clarifies that a few extra pages may be allocated to accommodate buffer management meta-data. Suggested-by: Steven Rostedt (VMware) Suggested-by: Joel Fernandes (Google) Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Joel Fernandes (Google) Signed-off-by: Frank A. Cancio Bello Link: https://lore.kernel.org/r/6f33be5f3d60e5ffc061d8d2b329d3d3ccf22a8c.1577231751.git.frank@generalsoftwareinc.com Signed-off-by: Jonathan Corbet --- Documentation/trace/ftrace.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 46df39300d22..8575aed7b74b 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -187,7 +187,8 @@ of ftrace. Here is a list of some of the key files: CPU buffer and not total size of all buffers. The trace buffers are allocated in pages (blocks of memory that the kernel uses for allocation, usually 4 KB in size). - If the last page allocated has room for more bytes + A few extra pages may be allocated to accommodate buffer management + meta-data. If the last page allocated has room for more bytes than requested, the rest of the page will be used, making the actual allocation bigger than requested or shown. ( Note, the size may not be a multiple of the page size -- cgit v1.2.3-59-g8ed1b From 5b8914a67e60cbc51137c3fb2ce8dcbfe9d096ab Mon Sep 17 00:00:00 2001 From: "Frank A. Cancio Bello" Date: Tue, 24 Dec 2019 19:06:27 -0500 Subject: docs: ftrace: Fix typos Fix minor typos in the doc. Suggested-by: Randy Dunlap Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Joel Fernandes (Google) Signed-off-by: Frank A. Cancio Bello Link: https://lore.kernel.org/r/9ef705d0208a4ca0852fed69bc0838a589a4df85.1577231751.git.frank@generalsoftwareinc.com Signed-off-by: Jonathan Corbet --- Documentation/trace/ftrace.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 8575aed7b74b..ff658e27d25b 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -238,7 +238,7 @@ of ftrace. Here is a list of some of the key files: This interface also allows for commands to be used. See the "Filter commands" section for more details. - As a speed up, since processing strings can't be quite expensive + As a speed up, since processing strings can be quite expensive and requires a check of all functions registered to tracing, instead an index can be written into this file. A number (starting with "1") written will instead select the same corresponding at the line position @@ -385,7 +385,7 @@ of ftrace. Here is a list of some of the key files: By default, 128 comms are saved (see "saved_cmdlines" above). To increase or decrease the amount of comms that are cached, echo - in a the number of comms to cache, into this file. + the number of comms to cache into this file. saved_tgids: @@ -3330,7 +3330,7 @@ directories after it is created. As you can see, the new directory looks similar to the tracing directory itself. In fact, it is very similar, except that the buffer and -events are agnostic from the main director, or from any other +events are agnostic from the main directory, or from any other instances that are created. The files in the new directory work just like the files with the -- cgit v1.2.3-59-g8ed1b From 1209f45f7dc4eeddfbe5786ceefe40a0e4b7195f Mon Sep 17 00:00:00 2001 From: "Frank A. Cancio Bello" Date: Tue, 24 Dec 2019 19:06:57 -0500 Subject: docs: ftrace: Fix small notation mistake The use of iff ("if and only if") notation is not accurate in this case. Suggested-by: Steven Rostedt (VMware) Signed-off-by: Frank A. Cancio Bello Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Joel Fernandes (Google) Link: https://lore.kernel.org/r/22f9a98a972c3155c7b478247a087a5efafde774.1577231751.git.frank@generalsoftwareinc.com Signed-off-by: Jonathan Corbet --- Documentation/trace/ring-buffer-design.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/trace/ring-buffer-design.txt b/Documentation/trace/ring-buffer-design.txt index ff747b6fa39b..2d53c6f25b91 100644 --- a/Documentation/trace/ring-buffer-design.txt +++ b/Documentation/trace/ring-buffer-design.txt @@ -37,7 +37,7 @@ commit_page - a pointer to the page with the last finished non-nested write. cmpxchg - hardware-assisted atomic transaction that performs the following: - A = B iff previous A == C + A = B if previous A == C R = cmpxchg(A, C, B) is saying that we replace A with B if and only if current A is equal to C, and we put the old (current) A into R -- cgit v1.2.3-59-g8ed1b From e43630edc376e3243bf73010ddf21690e81a9e38 Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Mon, 23 Dec 2019 00:31:21 -0300 Subject: Documentation: boot.rst: fix warnings Fix WARNING: Inline emphasis start-string without end-string. This warning was due to wrong syntax being used. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/20191223033121.1584930-1-dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/x86/boot.rst | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'Documentation') diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst index e0dc2ffb7094..71ecb6d0b3a6 100644 --- a/Documentation/x86/boot.rst +++ b/Documentation/x86/boot.rst @@ -835,14 +835,14 @@ Protocol: 2.09+ chunks of memory are occupied by kernel data. Thus setup_indirect struct and SETUP_INDIRECT type were introduced in - protocol 2.15. + protocol 2.15:: - struct setup_indirect { - __u32 type; - __u32 reserved; /* Reserved, must be set to zero. */ - __u64 len; - __u64 addr; - }; + struct setup_indirect { + __u32 type; + __u32 reserved; /* Reserved, must be set to zero. */ + __u64 len; + __u64 addr; + }; The type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be SETUP_INDIRECT itself since making the setup_indirect a tree structure @@ -850,19 +850,19 @@ Protocol: 2.09+ and stack space can be limited in boot contexts. Let's give an example how to point to SETUP_E820_EXT data using setup_indirect. - In this case setup_data and setup_indirect will look like this: - - struct setup_data { - __u64 next = 0 or ; - __u32 type = SETUP_INDIRECT; - __u32 len = sizeof(setup_data); - __u8 data[sizeof(setup_indirect)] = struct setup_indirect { - __u32 type = SETUP_INDIRECT | SETUP_E820_EXT; - __u32 reserved = 0; - __u64 len = ; - __u64 addr = ; + In this case setup_data and setup_indirect will look like this:: + + struct setup_data { + __u64 next = 0 or ; + __u32 type = SETUP_INDIRECT; + __u32 len = sizeof(setup_data); + __u8 data[sizeof(setup_indirect)] = struct setup_indirect { + __u32 type = SETUP_INDIRECT | SETUP_E820_EXT; + __u32 reserved = 0; + __u64 len = ; + __u64 addr = ; + } } - } .. note:: SETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished @@ -965,7 +965,7 @@ expected to copy into a setup_data chunk. All kernel_info data should be part of this structure. Fixed size data have to be put before kernel_info_var_len_data label. Variable size data have to be put after kernel_info_var_len_data label. Each chunk of variable size data has to -be prefixed with header/magic and its size, e.g.: +be prefixed with header/magic and its size, e.g.:: kernel_info: .ascii "LToP" /* Header, Linux top (structure). */ -- cgit v1.2.3-59-g8ed1b From a1986433a9fd7a0410c9267805e19bcbdcffa2fc Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Sun, 22 Dec 2019 22:00:30 -0300 Subject: Documentation: filesystems: convert vfat.txt to RST Converts vfat.txt to the reStructuredText format, improving presentation without changing the underlying content. Signed-off-by: Daniel W. S. Almeida ----------------------------------------------------------- Changes in v3: Removed unnecessary markup. Removed section "BUG REPORTS" as recommended by the maintainer. Changes in v2: Refactored long lines as pointed out by Jonathan Copied the maintainer Updated the reference in the MAINTAINERS file for vfat I did not move this into admin-guide, waiting on what the maintainer has to say about this and also about old sections in the text, if any. Link: https://lore.kernel.org/r/20191223010030.434902-1-dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/filesystems/index.rst | 1 + Documentation/filesystems/vfat.rst | 387 ++++++++++++++++++++++++++++++++++++ Documentation/filesystems/vfat.txt | 347 -------------------------------- MAINTAINERS | 2 +- 4 files changed, 389 insertions(+), 348 deletions(-) create mode 100644 Documentation/filesystems/vfat.rst delete mode 100644 Documentation/filesystems/vfat.txt (limited to 'Documentation') diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index ad6315a48d14..b03578063801 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -48,3 +48,4 @@ Documentation for filesystem implementations. autofs virtiofs + vfat diff --git a/Documentation/filesystems/vfat.rst b/Documentation/filesystems/vfat.rst new file mode 100644 index 000000000000..e85d74e91295 --- /dev/null +++ b/Documentation/filesystems/vfat.rst @@ -0,0 +1,387 @@ +==== +VFAT +==== + +USING VFAT +========== + +To use the vfat filesystem, use the filesystem type 'vfat'. i.e.:: + + mount -t vfat /dev/fd0 /mnt + + +No special partition formatter is required, +'mkdosfs' will work fine if you want to format from within Linux. + +VFAT MOUNT OPTIONS +================== + +**uid=###** + Set the owner of all files on this filesystem. + The default is the uid of current process. + +**gid=###** + Set the group of all files on this filesystem. + The default is the gid of current process. + +**umask=###** + The permission mask (for files and directories, see *umask(1)*). + The default is the umask of current process. + +**dmask=###** + The permission mask for the directory. + The default is the umask of current process. + +**fmask=###** + The permission mask for files. + The default is the umask of current process. + +**allow_utime=###** + This option controls the permission check of mtime/atime. + + **-20**: If current process is in group of file's group ID, + you can change timestamp. + + **-2**: Other users can change timestamp. + + The default is set from dmask option. If the directory is + writable, utime(2) is also allowed. i.e. ~dmask & 022. + + Normally utime(2) checks current process is owner of + the file, or it has CAP_FOWNER capability. But FAT + filesystem doesn't have uid/gid on disk, so normal + check is too unflexible. With this option you can + relax it. + +**codepage=###** + Sets the codepage number for converting to shortname + characters on FAT filesystem. + By default, FAT_DEFAULT_CODEPAGE setting is used. + +**iocharset=** + Character set to use for converting between the + encoding is used for user visible filename and 16 bit + Unicode characters. Long filenames are stored on disk + in Unicode format, but Unix for the most part doesn't + know how to deal with Unicode. + By default, FAT_DEFAULT_IOCHARSET setting is used. + + There is also an option of doing UTF-8 translations + with the utf8 option. + +.. note:: ``iocharset=utf8`` is not recommended. If unsure, you should consider + the utf8 option instead. + +**utf8=** + UTF-8 is the filesystem safe version of Unicode that + is used by the console. It can be enabled or disabled + for the filesystem with this option. + If 'uni_xlate' gets set, UTF-8 gets disabled. + By default, FAT_DEFAULT_UTF8 setting is used. + +**uni_xlate=** + Translate unhandled Unicode characters to special + escaped sequences. This would let you backup and + restore filenames that are created with any Unicode + characters. Until Linux supports Unicode for real, + this gives you an alternative. Without this option, + a '?' is used when no translation is possible. The + escape character is ':' because it is otherwise + illegal on the vfat filesystem. The escape sequence + that gets used is ':' and the four digits of hexadecimal + unicode. + +**nonumtail=** + When creating 8.3 aliases, normally the alias will + end in '~1' or tilde followed by some number. If this + option is set, then if the filename is + "longfilename.txt" and "longfile.txt" does not + currently exist in the directory, longfile.txt will + be the short alias instead of longfi~1.txt. + +**usefree** + Use the "free clusters" value stored on FSINFO. It will + be used to determine number of free clusters without + scanning disk. But it's not used by default, because + recent Windows don't update it correctly in some + case. If you are sure the "free clusters" on FSINFO is + correct, by this option you can avoid scanning disk. + +**quiet** + Stops printing certain warning messages. + +**check=s|r|n** + Case sensitivity checking setting. + + **s**: strict, case sensitive + + **r**: relaxed, case insensitive + + **n**: normal, default setting, currently case insensitive + +**nocase** + This was deprecated for vfat. Use ``shortname=win95`` instead. + +**shortname=lower|win95|winnt|mixed** + Shortname display/create setting. + + **lower**: convert to lowercase for display, + emulate the Windows 95 rule for create. + + **win95**: emulate the Windows 95 rule for display/create. + + **winnt**: emulate the Windows NT rule for display/create. + + **mixed**: emulate the Windows NT rule for display, + emulate the Windows 95 rule for create. + + Default setting is `mixed`. + +**tz=UTC** + Interpret timestamps as UTC rather than local time. + This option disables the conversion of timestamps + between local time (as used by Windows on FAT) and UTC + (which Linux uses internally). This is particularly + useful when mounting devices (like digital cameras) + that are set to UTC in order to avoid the pitfalls of + local time. + +**time_offset=minutes** + Set offset for conversion of timestamps from local time + used by FAT to UTC. I.e. minutes will be subtracted + from each timestamp to convert it to UTC used internally by + Linux. This is useful when time zone set in ``sys_tz`` is + not the time zone used by the filesystem. Note that this + option still does not provide correct time stamps in all + cases in presence of DST - time stamps in a different DST + setting will be off by one hour. + +**showexec** + If set, the execute permission bits of the file will be + allowed only if the extension part of the name is .EXE, + .COM, or .BAT. Not set by default. + +**debug** + Can be set, but unused by the current implementation. + +**sys_immutable** + If set, ATTR_SYS attribute on FAT is handled as + IMMUTABLE flag on Linux. Not set by default. + +**flush** + If set, the filesystem will try to flush to disk more + early than normal. Not set by default. + +**rodir** + FAT has the ATTR_RO (read-only) attribute. On Windows, + the ATTR_RO of the directory will just be ignored, + and is used only by applications as a flag (e.g. it's set + for the customized folder). + + If you want to use ATTR_RO as read-only flag even for + the directory, set this option. + +**errors=panic|continue|remount-ro** + specify FAT behavior on critical errors: panic, continue + without doing anything or remount the partition in + read-only mode (default behavior). + +**discard** + If set, issues discard/TRIM commands to the block + device when blocks are freed. This is useful for SSD devices + and sparse/thinly-provisoned LUNs. + +**nfs=stale_rw|nostale_ro** + Enable this only if you want to export the FAT filesystem + over NFS. + + **stale_rw**: This option maintains an index (cache) of directory + *inodes* by *i_logstart* which is used by the nfs-related code to + improve look-ups. Full file operations (read/write) over NFS is + supported but with cache eviction at NFS server, this could + result in ESTALE issues. + + **nostale_ro**: This option bases the *inode* number and filehandle + on the on-disk location of a file in the MS-DOS directory entry. + This ensures that ESTALE will not be returned after a file is + evicted from the inode cache. However, it means that operations + such as rename, create and unlink could cause filehandles that + previously pointed at one file to point at a different file, + potentially causing data corruption. For this reason, this + option also mounts the filesystem readonly. + + To maintain backward compatibility, ``'-o nfs'`` is also accepted, + defaulting to "stale_rw". + +**dos1xfloppy : 0,1,yes,no,true,false** + If set, use a fallback default BIOS Parameter Block + configuration, determined by backing device size. These static + parameters match defaults assumed by DOS 1.x for 160 kiB, + 180 kiB, 320 kiB, and 360 kiB floppies and floppy images. + + + +LIMITATION +========== + +The fallocated region of file is discarded at umount/evict time +when using fallocate with FALLOC_FL_KEEP_SIZE. +So, User should assume that fallocated region can be discarded at +last close if there is memory pressure resulting in eviction of +the inode from the memory. As a result, for any dependency on +the fallocated region, user should make sure to recheck fallocate +after reopening the file. + +TODO +==== +Need to get rid of the raw scanning stuff. Instead, always use +a get next directory entry approach. The only thing left that uses +raw scanning is the directory renaming code. + + +POSSIBLE PROBLEMS +================= + +- vfat_valid_longname does not properly checked reserved names. +- When a volume name is the same as a directory name in the root + directory of the filesystem, the directory name sometimes shows + up as an empty file. +- autoconv option does not work correctly. + + +TEST SUITE +========== +If you plan to make any modifications to the vfat filesystem, please +get the test suite that comes with the vfat distribution at + +``_ + +This tests quite a few parts of the vfat filesystem and additional +tests for new features or untested features would be appreciated. + +NOTES ON THE STRUCTURE OF THE VFAT FILESYSTEM +============================================= +This documentation was provided by Galen C. Hunt gchunt@cs.rochester.edu and +lightly annotated by Gordon Chaffee. + +This document presents a very rough, technical overview of my +knowledge of the extended FAT file system used in Windows NT 3.5 and +Windows 95. I don't guarantee that any of the following is correct, +but it appears to be so. + +The extended FAT file system is almost identical to the FAT +file system used in DOS versions up to and including *6.223410239847* +:-). The significant change has been the addition of long file names. +These names support up to 255 characters including spaces and lower +case characters as opposed to the traditional 8.3 short names. + +Here is the description of the traditional FAT entry in the current +Windows 95 filesystem:: + + struct directory { // Short 8.3 names + unsigned char name[8]; // file name + unsigned char ext[3]; // file extension + unsigned char attr; // attribute byte + unsigned char lcase; // Case for base and extension + unsigned char ctime_ms; // Creation time, milliseconds + unsigned char ctime[2]; // Creation time + unsigned char cdate[2]; // Creation date + unsigned char adate[2]; // Last access date + unsigned char reserved[2]; // reserved values (ignored) + unsigned char time[2]; // time stamp + unsigned char date[2]; // date stamp + unsigned char start[2]; // starting cluster number + unsigned char size[4]; // size of the file + }; + + +The lcase field specifies if the base and/or the extension of an 8.3 +name should be capitalized. This field does not seem to be used by +Windows 95 but it is used by Windows NT. The case of filenames is not +completely compatible from Windows NT to Windows 95. It is not completely +compatible in the reverse direction, however. Filenames that fit in +the 8.3 namespace and are written on Windows NT to be lowercase will +show up as uppercase on Windows 95. + +.. note:: Note that the ``start`` and ``size`` values are actually little + endian integer values. The descriptions of the fields in this + structure are public knowledge and can be found elsewhere. + +With the extended FAT system, Microsoft has inserted extra +directory entries for any files with extended names. (Any name which +legally fits within the old 8.3 encoding scheme does not have extra +entries.) I call these extra entries slots. Basically, a slot is a +specially formatted directory entry which holds up to 13 characters of +a file's extended name. Think of slots as additional labeling for the +directory entry of the file to which they correspond. Microsoft +prefers to refer to the 8.3 entry for a file as its alias and the +extended slot directory entries as the file name. + +The C structure for a slot directory entry follows:: + + struct slot { // Up to 13 characters of a long name + unsigned char id; // sequence number for slot + unsigned char name0_4[10]; // first 5 characters in name + unsigned char attr; // attribute byte + unsigned char reserved; // always 0 + unsigned char alias_checksum; // checksum for 8.3 alias + unsigned char name5_10[12]; // 6 more characters in name + unsigned char start[2]; // starting cluster number + unsigned char name11_12[4]; // last 2 characters in name + }; + + +If the layout of the slots looks a little odd, it's only +because of Microsoft's efforts to maintain compatibility with old +software. The slots must be disguised to prevent old software from +panicking. To this end, a number of measures are taken: + + 1) The attribute byte for a slot directory entry is always set + to 0x0f. This corresponds to an old directory entry with + attributes of "hidden", "system", "read-only", and "volume + label". Most old software will ignore any directory + entries with the "volume label" bit set. Real volume label + entries don't have the other three bits set. + + 2) The starting cluster is always set to 0, an impossible + value for a DOS file. + +Because the extended FAT system is backward compatible, it is +possible for old software to modify directory entries. Measures must +be taken to ensure the validity of slots. An extended FAT system can +verify that a slot does in fact belong to an 8.3 directory entry by +the following: + + 1) Positioning. Slots for a file always immediately proceed + their corresponding 8.3 directory entry. In addition, each + slot has an id which marks its order in the extended file + name. Here is a very abbreviated view of an 8.3 directory + entry and its corresponding long name slots for the file + "My Big File.Extension which is long":: + + + + + + + + + .. note:: Note that the slots are stored from last to first. Slots + are numbered from 1 to N. The Nth slot is ``or'ed`` with + 0x40 to mark it as the last one. + + 2) Checksum. Each slot has an alias_checksum value. The + checksum is calculated from the 8.3 name using the + following algorithm:: + + for (sum = i = 0; i < 11; i++) { + sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + name[i] + } + + + 3) If there is free space in the final slot, a Unicode ``NULL (0x0000)`` + is stored after the final character. After that, all unused + characters in the final slot are set to Unicode 0xFFFF. + +Finally, note that the extended name is stored in Unicode. Each Unicode +character takes either two or four bytes, UTF-16LE encoded. diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt deleted file mode 100644 index 91031298beb1..000000000000 --- a/Documentation/filesystems/vfat.txt +++ /dev/null @@ -1,347 +0,0 @@ -USING VFAT ----------------------------------------------------------------------- -To use the vfat filesystem, use the filesystem type 'vfat'. i.e. - mount -t vfat /dev/fd0 /mnt - -No special partition formatter is required. mkdosfs will work fine -if you want to format from within Linux. - -VFAT MOUNT OPTIONS ----------------------------------------------------------------------- -uid=### -- Set the owner of all files on this filesystem. - The default is the uid of current process. - -gid=### -- Set the group of all files on this filesystem. - The default is the gid of current process. - -umask=### -- The permission mask (for files and directories, see umask(1)). - The default is the umask of current process. - -dmask=### -- The permission mask for the directory. - The default is the umask of current process. - -fmask=### -- The permission mask for files. - The default is the umask of current process. - -allow_utime=### -- This option controls the permission check of mtime/atime. - - 20 - If current process is in group of file's group ID, - you can change timestamp. - 2 - Other users can change timestamp. - - The default is set from `dmask' option. (If the directory is - writable, utime(2) is also allowed. I.e. ~dmask & 022) - - Normally utime(2) checks current process is owner of - the file, or it has CAP_FOWNER capability. But FAT - filesystem doesn't have uid/gid on disk, so normal - check is too unflexible. With this option you can - relax it. - -codepage=### -- Sets the codepage number for converting to shortname - characters on FAT filesystem. - By default, FAT_DEFAULT_CODEPAGE setting is used. - -iocharset= -- Character set to use for converting between the - encoding is used for user visible filename and 16 bit - Unicode characters. Long filenames are stored on disk - in Unicode format, but Unix for the most part doesn't - know how to deal with Unicode. - By default, FAT_DEFAULT_IOCHARSET setting is used. - - There is also an option of doing UTF-8 translations - with the utf8 option. - - NOTE: "iocharset=utf8" is not recommended. If unsure, - you should consider the following option instead. - -utf8= -- UTF-8 is the filesystem safe version of Unicode that - is used by the console. It can be enabled or disabled - for the filesystem with this option. - If 'uni_xlate' gets set, UTF-8 gets disabled. - By default, FAT_DEFAULT_UTF8 setting is used. - -uni_xlate= -- Translate unhandled Unicode characters to special - escaped sequences. This would let you backup and - restore filenames that are created with any Unicode - characters. Until Linux supports Unicode for real, - this gives you an alternative. Without this option, - a '?' is used when no translation is possible. The - escape character is ':' because it is otherwise - illegal on the vfat filesystem. The escape sequence - that gets used is ':' and the four digits of hexadecimal - unicode. - -nonumtail= -- When creating 8.3 aliases, normally the alias will - end in '~1' or tilde followed by some number. If this - option is set, then if the filename is - "longfilename.txt" and "longfile.txt" does not - currently exist in the directory, 'longfile.txt' will - be the short alias instead of 'longfi~1.txt'. - -usefree -- Use the "free clusters" value stored on FSINFO. It'll - be used to determine number of free clusters without - scanning disk. But it's not used by default, because - recent Windows don't update it correctly in some - case. If you are sure the "free clusters" on FSINFO is - correct, by this option you can avoid scanning disk. - -quiet -- Stops printing certain warning messages. - -check=s|r|n -- Case sensitivity checking setting. - s: strict, case sensitive - r: relaxed, case insensitive - n: normal, default setting, currently case insensitive - -nocase -- This was deprecated for vfat. Use shortname=win95 instead. - -shortname=lower|win95|winnt|mixed - -- Shortname display/create setting. - lower: convert to lowercase for display, - emulate the Windows 95 rule for create. - win95: emulate the Windows 95 rule for display/create. - winnt: emulate the Windows NT rule for display/create. - mixed: emulate the Windows NT rule for display, - emulate the Windows 95 rule for create. - Default setting is `mixed'. - -tz=UTC -- Interpret timestamps as UTC rather than local time. - This option disables the conversion of timestamps - between local time (as used by Windows on FAT) and UTC - (which Linux uses internally). This is particularly - useful when mounting devices (like digital cameras) - that are set to UTC in order to avoid the pitfalls of - local time. -time_offset=minutes - -- Set offset for conversion of timestamps from local time - used by FAT to UTC. I.e. minutes will be subtracted - from each timestamp to convert it to UTC used internally by - Linux. This is useful when time zone set in sys_tz is - not the time zone used by the filesystem. Note that this - option still does not provide correct time stamps in all - cases in presence of DST - time stamps in a different DST - setting will be off by one hour. - -showexec -- If set, the execute permission bits of the file will be - allowed only if the extension part of the name is .EXE, - .COM, or .BAT. Not set by default. - -debug -- Can be set, but unused by the current implementation. - -sys_immutable -- If set, ATTR_SYS attribute on FAT is handled as - IMMUTABLE flag on Linux. Not set by default. - -flush -- If set, the filesystem will try to flush to disk more - early than normal. Not set by default. - -rodir -- FAT has the ATTR_RO (read-only) attribute. On Windows, - the ATTR_RO of the directory will just be ignored, - and is used only by applications as a flag (e.g. it's set - for the customized folder). - - If you want to use ATTR_RO as read-only flag even for - the directory, set this option. - -errors=panic|continue|remount-ro - -- specify FAT behavior on critical errors: panic, continue - without doing anything or remount the partition in - read-only mode (default behavior). - -discard -- If set, issues discard/TRIM commands to the block - device when blocks are freed. This is useful for SSD devices - and sparse/thinly-provisoned LUNs. - -nfs=stale_rw|nostale_ro - Enable this only if you want to export the FAT filesystem - over NFS. - - stale_rw: This option maintains an index (cache) of directory - inodes by i_logstart which is used by the nfs-related code to - improve look-ups. Full file operations (read/write) over NFS is - supported but with cache eviction at NFS server, this could - result in ESTALE issues. - - nostale_ro: This option bases the inode number and filehandle - on the on-disk location of a file in the MS-DOS directory entry. - This ensures that ESTALE will not be returned after a file is - evicted from the inode cache. However, it means that operations - such as rename, create and unlink could cause filehandles that - previously pointed at one file to point at a different file, - potentially causing data corruption. For this reason, this - option also mounts the filesystem readonly. - - To maintain backward compatibility, '-o nfs' is also accepted, - defaulting to stale_rw - -dos1xfloppy -- If set, use a fallback default BIOS Parameter Block - configuration, determined by backing device size. These static - parameters match defaults assumed by DOS 1.x for 160 kiB, - 180 kiB, 320 kiB, and 360 kiB floppies and floppy images. - - -: 0,1,yes,no,true,false - -LIMITATION ---------------------------------------------------------------------- -* The fallocated region of file is discarded at umount/evict time - when using fallocate with FALLOC_FL_KEEP_SIZE. - So, User should assume that fallocated region can be discarded at - last close if there is memory pressure resulting in eviction of - the inode from the memory. As a result, for any dependency on - the fallocated region, user should make sure to recheck fallocate - after reopening the file. - -TODO ----------------------------------------------------------------------- -* Need to get rid of the raw scanning stuff. Instead, always use - a get next directory entry approach. The only thing left that uses - raw scanning is the directory renaming code. - - -POSSIBLE PROBLEMS ----------------------------------------------------------------------- -* vfat_valid_longname does not properly checked reserved names. -* When a volume name is the same as a directory name in the root - directory of the filesystem, the directory name sometimes shows - up as an empty file. -* autoconv option does not work correctly. - -BUG REPORTS ----------------------------------------------------------------------- -If you have trouble with the VFAT filesystem, mail bug reports to -chaffee@bmrc.cs.berkeley.edu. Please specify the filename -and the operation that gave you trouble. - -TEST SUITE ----------------------------------------------------------------------- -If you plan to make any modifications to the vfat filesystem, please -get the test suite that comes with the vfat distribution at - - http://web.archive.org/web/*/http://bmrc.berkeley.edu/ - people/chaffee/vfat.html - -This tests quite a few parts of the vfat filesystem and additional -tests for new features or untested features would be appreciated. - -NOTES ON THE STRUCTURE OF THE VFAT FILESYSTEM ----------------------------------------------------------------------- -(This documentation was provided by Galen C. Hunt - and lightly annotated by Gordon Chaffee). - -This document presents a very rough, technical overview of my -knowledge of the extended FAT file system used in Windows NT 3.5 and -Windows 95. I don't guarantee that any of the following is correct, -but it appears to be so. - -The extended FAT file system is almost identical to the FAT -file system used in DOS versions up to and including 6.223410239847 -:-). The significant change has been the addition of long file names. -These names support up to 255 characters including spaces and lower -case characters as opposed to the traditional 8.3 short names. - -Here is the description of the traditional FAT entry in the current -Windows 95 filesystem: - - struct directory { // Short 8.3 names - unsigned char name[8]; // file name - unsigned char ext[3]; // file extension - unsigned char attr; // attribute byte - unsigned char lcase; // Case for base and extension - unsigned char ctime_ms; // Creation time, milliseconds - unsigned char ctime[2]; // Creation time - unsigned char cdate[2]; // Creation date - unsigned char adate[2]; // Last access date - unsigned char reserved[2]; // reserved values (ignored) - unsigned char time[2]; // time stamp - unsigned char date[2]; // date stamp - unsigned char start[2]; // starting cluster number - unsigned char size[4]; // size of the file - }; - -The lcase field specifies if the base and/or the extension of an 8.3 -name should be capitalized. This field does not seem to be used by -Windows 95 but it is used by Windows NT. The case of filenames is not -completely compatible from Windows NT to Windows 95. It is not completely -compatible in the reverse direction, however. Filenames that fit in -the 8.3 namespace and are written on Windows NT to be lowercase will -show up as uppercase on Windows 95. - -Note that the "start" and "size" values are actually little -endian integer values. The descriptions of the fields in this -structure are public knowledge and can be found elsewhere. - -With the extended FAT system, Microsoft has inserted extra -directory entries for any files with extended names. (Any name which -legally fits within the old 8.3 encoding scheme does not have extra -entries.) I call these extra entries slots. Basically, a slot is a -specially formatted directory entry which holds up to 13 characters of -a file's extended name. Think of slots as additional labeling for the -directory entry of the file to which they correspond. Microsoft -prefers to refer to the 8.3 entry for a file as its alias and the -extended slot directory entries as the file name. - -The C structure for a slot directory entry follows: - - struct slot { // Up to 13 characters of a long name - unsigned char id; // sequence number for slot - unsigned char name0_4[10]; // first 5 characters in name - unsigned char attr; // attribute byte - unsigned char reserved; // always 0 - unsigned char alias_checksum; // checksum for 8.3 alias - unsigned char name5_10[12]; // 6 more characters in name - unsigned char start[2]; // starting cluster number - unsigned char name11_12[4]; // last 2 characters in name - }; - -If the layout of the slots looks a little odd, it's only -because of Microsoft's efforts to maintain compatibility with old -software. The slots must be disguised to prevent old software from -panicking. To this end, a number of measures are taken: - - 1) The attribute byte for a slot directory entry is always set - to 0x0f. This corresponds to an old directory entry with - attributes of "hidden", "system", "read-only", and "volume - label". Most old software will ignore any directory - entries with the "volume label" bit set. Real volume label - entries don't have the other three bits set. - - 2) The starting cluster is always set to 0, an impossible - value for a DOS file. - -Because the extended FAT system is backward compatible, it is -possible for old software to modify directory entries. Measures must -be taken to ensure the validity of slots. An extended FAT system can -verify that a slot does in fact belong to an 8.3 directory entry by -the following: - - 1) Positioning. Slots for a file always immediately proceed - their corresponding 8.3 directory entry. In addition, each - slot has an id which marks its order in the extended file - name. Here is a very abbreviated view of an 8.3 directory - entry and its corresponding long name slots for the file - "My Big File.Extension which is long": - - - - - - - - Note that the slots are stored from last to first. Slots - are numbered from 1 to N. The Nth slot is or'ed with 0x40 - to mark it as the last one. - - 2) Checksum. Each slot has an "alias_checksum" value. The - checksum is calculated from the 8.3 name using the - following algorithm: - - for (sum = i = 0; i < 11; i++) { - sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + name[i] - } - - 3) If there is free space in the final slot, a Unicode NULL (0x0000) - is stored after the final character. After that, all unused - characters in the final slot are set to Unicode 0xFFFF. - -Finally, note that the extended name is stored in Unicode. Each Unicode -character takes either two or four bytes, UTF-16LE encoded. diff --git a/MAINTAINERS b/MAINTAINERS index cc0a4a8ae06a..1df6007d6414 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17356,7 +17356,7 @@ F: drivers/mtd/nand/raw/vf610_nfc.c VFAT/FAT/MSDOS FILESYSTEM M: OGAWA Hirofumi S: Maintained -F: Documentation/filesystems/vfat.txt +F: Documentation/filesystems/vfat.rst F: fs/fat/ VFIO DRIVER -- cgit v1.2.3-59-g8ed1b From 2f123b9a359650374712e812c0c466f75e77ba0e Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:23 -0300 Subject: Documentation: convert nfs.txt to ReST This patch converts nfs.txt to RST. It also moves it to admin-guide. The reason for moving it is because this document contains information useful for system administrators, as noted on the following paragraph: 'The purpose of this document is to provide information on some of the special features of the NFS client that can be configured by system administrators'. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/cb9f2da2f2f6dd432b4cf9e05f79f74f4d54b6ab.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/index.rst | 1 + Documentation/admin-guide/nfs/index.rst | 8 ++ Documentation/admin-guide/nfs/nfs-client.rst | 141 +++++++++++++++++++++++++++ Documentation/filesystems/nfs/nfs.txt | 136 -------------------------- 4 files changed, 150 insertions(+), 136 deletions(-) create mode 100644 Documentation/admin-guide/nfs/index.rst create mode 100644 Documentation/admin-guide/nfs/nfs-client.rst delete mode 100644 Documentation/filesystems/nfs/nfs.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst index 4405b7485312..4433f3929481 100644 --- a/Documentation/admin-guide/index.rst +++ b/Documentation/admin-guide/index.rst @@ -76,6 +76,7 @@ configure specific aspects of kernel behavior to your liking. device-mapper/index efi-stub ext4 + nfs/index gpio/index highuid hw_random diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst new file mode 100644 index 000000000000..2fe77091c25c --- /dev/null +++ b/Documentation/admin-guide/nfs/index.rst @@ -0,0 +1,8 @@ +============= +NFS +============= + +.. toctree:: + :maxdepth: 1 + + nfs-client diff --git a/Documentation/admin-guide/nfs/nfs-client.rst b/Documentation/admin-guide/nfs/nfs-client.rst new file mode 100644 index 000000000000..c4b777c7584b --- /dev/null +++ b/Documentation/admin-guide/nfs/nfs-client.rst @@ -0,0 +1,141 @@ +========== +NFS Client +========== + +The NFS client +============== + +The NFS version 2 protocol was first documented in RFC1094 (March 1989). +Since then two more major releases of NFS have been published, with NFSv3 +being documented in RFC1813 (June 1995), and NFSv4 in RFC3530 (April +2003). + +The Linux NFS client currently supports all the above published versions, +and work is in progress on adding support for minor version 1 of the NFSv4 +protocol. + +The purpose of this document is to provide information on some of the +special features of the NFS client that can be configured by system +administrators. + + +The nfs4_unique_id parameter +============================ + +NFSv4 requires clients to identify themselves to servers with a unique +string. File open and lock state shared between one client and one server +is associated with this identity. To support robust NFSv4 state recovery +and transparent state migration, this identity string must not change +across client reboots. + +Without any other intervention, the Linux client uses a string that contains +the local system's node name. System administrators, however, often do not +take care to ensure that node names are fully qualified and do not change +over the lifetime of a client system. Node names can have other +administrative requirements that require particular behavior that does not +work well as part of an nfs_client_id4 string. + +The nfs.nfs4_unique_id boot parameter specifies a unique string that can be +used instead of a system's node name when an NFS client identifies itself to +a server. Thus, if the system's node name is not unique, or it changes, its +nfs.nfs4_unique_id stays the same, preventing collision with other clients +or loss of state during NFS reboot recovery or transparent state migration. + +The nfs.nfs4_unique_id string is typically a UUID, though it can contain +anything that is believed to be unique across all NFS clients. An +nfs4_unique_id string should be chosen when a client system is installed, +just as a system's root file system gets a fresh UUID in its label at +install time. + +The string should remain fixed for the lifetime of the client. It can be +changed safely if care is taken that the client shuts down cleanly and all +outstanding NFSv4 state has expired, to prevent loss of NFSv4 state. + +This string can be stored in an NFS client's grub.conf, or it can be provided +via a net boot facility such as PXE. It may also be specified as an nfs.ko +module parameter. Specifying a uniquifier string is not support for NFS +clients running in containers. + + +The DNS resolver +================ + +NFSv4 allows for one server to refer the NFS client to data that has been +migrated onto another server by means of the special "fs_locations" +attribute. See `RFC3530 Section 6: Filesystem Migration and Replication`_ and +`Implementation Guide for Referrals in NFSv4`_. + +.. _RFC3530 Section 6\: Filesystem Migration and Replication: http://tools.ietf.org/html/rfc3530#section-6 +.. _Implementation Guide for Referrals in NFSv4: http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00 + +The fs_locations information can take the form of either an ip address and +a path, or a DNS hostname and a path. The latter requires the NFS client to +do a DNS lookup in order to mount the new volume, and hence the need for an +upcall to allow userland to provide this service. + +Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual +/var/lib/nfs/rpc_pipefs, the upcall consists of the following steps: + + (1) The process checks the dns_resolve cache to see if it contains a + valid entry. If so, it returns that entry and exits. + + (2) If no valid entry exists, the helper script '/sbin/nfs_cache_getent' + (may be changed using the 'nfs.cache_getent' kernel boot parameter) + is run, with two arguments: + - the cache name, "dns_resolve" + - the hostname to resolve + + (3) After looking up the corresponding ip address, the helper script + writes the result into the rpc_pipefs pseudo-file + '/var/lib/nfs/rpc_pipefs/cache/dns_resolve/channel' + in the following (text) format: + + " \n" + + Where is in the usual IPv4 (123.456.78.90) or IPv6 + (ffee:ddcc:bbaa:9988:7766:5544:3322:1100, ffee::1100, ...) format. + is identical to the second argument of the helper + script, and is the 'time to live' of this cache entry (in + units of seconds). + + .. note:: + If is invalid, say the string "0", then a negative + entry is created, which will cause the kernel to treat the hostname + as having no valid DNS translation. + + + + +A basic sample /sbin/nfs_cache_getent +===================================== +.. code-block:: sh + + #!/bin/bash + # + ttl=600 + # + cut=/usr/bin/cut + getent=/usr/bin/getent + rpc_pipefs=/var/lib/nfs/rpc_pipefs + # + die() + { + echo "Usage: $0 cache_name entry_name" + exit 1 + } + + [ $# -lt 2 ] && die + cachename="$1" + cache_path=${rpc_pipefs}/cache/${cachename}/channel + + case "${cachename}" in + dns_resolve) + name="$2" + result="$(${getent} hosts ${name} | ${cut} -f1 -d\ )" + [ -z "${result}" ] && result="0" + ;; + *) + die + ;; + esac + echo "${result} ${name} ${ttl}" >${cache_path} diff --git a/Documentation/filesystems/nfs/nfs.txt b/Documentation/filesystems/nfs/nfs.txt deleted file mode 100644 index f2571c8bef74..000000000000 --- a/Documentation/filesystems/nfs/nfs.txt +++ /dev/null @@ -1,136 +0,0 @@ - -The NFS client -============== - -The NFS version 2 protocol was first documented in RFC1094 (March 1989). -Since then two more major releases of NFS have been published, with NFSv3 -being documented in RFC1813 (June 1995), and NFSv4 in RFC3530 (April -2003). - -The Linux NFS client currently supports all the above published versions, -and work is in progress on adding support for minor version 1 of the NFSv4 -protocol. - -The purpose of this document is to provide information on some of the -special features of the NFS client that can be configured by system -administrators. - - -The nfs4_unique_id parameter -============================ - -NFSv4 requires clients to identify themselves to servers with a unique -string. File open and lock state shared between one client and one server -is associated with this identity. To support robust NFSv4 state recovery -and transparent state migration, this identity string must not change -across client reboots. - -Without any other intervention, the Linux client uses a string that contains -the local system's node name. System administrators, however, often do not -take care to ensure that node names are fully qualified and do not change -over the lifetime of a client system. Node names can have other -administrative requirements that require particular behavior that does not -work well as part of an nfs_client_id4 string. - -The nfs.nfs4_unique_id boot parameter specifies a unique string that can be -used instead of a system's node name when an NFS client identifies itself to -a server. Thus, if the system's node name is not unique, or it changes, its -nfs.nfs4_unique_id stays the same, preventing collision with other clients -or loss of state during NFS reboot recovery or transparent state migration. - -The nfs.nfs4_unique_id string is typically a UUID, though it can contain -anything that is believed to be unique across all NFS clients. An -nfs4_unique_id string should be chosen when a client system is installed, -just as a system's root file system gets a fresh UUID in its label at -install time. - -The string should remain fixed for the lifetime of the client. It can be -changed safely if care is taken that the client shuts down cleanly and all -outstanding NFSv4 state has expired, to prevent loss of NFSv4 state. - -This string can be stored in an NFS client's grub.conf, or it can be provided -via a net boot facility such as PXE. It may also be specified as an nfs.ko -module parameter. Specifying a uniquifier string is not support for NFS -clients running in containers. - - -The DNS resolver -================ - -NFSv4 allows for one server to refer the NFS client to data that has been -migrated onto another server by means of the special "fs_locations" -attribute. See - http://tools.ietf.org/html/rfc3530#section-6 -and - http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00 - -The fs_locations information can take the form of either an ip address and -a path, or a DNS hostname and a path. The latter requires the NFS client to -do a DNS lookup in order to mount the new volume, and hence the need for an -upcall to allow userland to provide this service. - -Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual -/var/lib/nfs/rpc_pipefs, the upcall consists of the following steps: - - (1) The process checks the dns_resolve cache to see if it contains a - valid entry. If so, it returns that entry and exits. - - (2) If no valid entry exists, the helper script '/sbin/nfs_cache_getent' - (may be changed using the 'nfs.cache_getent' kernel boot parameter) - is run, with two arguments: - - the cache name, "dns_resolve" - - the hostname to resolve - - (3) After looking up the corresponding ip address, the helper script - writes the result into the rpc_pipefs pseudo-file - '/var/lib/nfs/rpc_pipefs/cache/dns_resolve/channel' - in the following (text) format: - - " \n" - - Where is in the usual IPv4 (123.456.78.90) or IPv6 - (ffee:ddcc:bbaa:9988:7766:5544:3322:1100, ffee::1100, ...) format. - is identical to the second argument of the helper - script, and is the 'time to live' of this cache entry (in - units of seconds). - - Note: If is invalid, say the string "0", then a negative - entry is created, which will cause the kernel to treat the hostname - as having no valid DNS translation. - - - - -A basic sample /sbin/nfs_cache_getent -===================================== - -#!/bin/bash -# -ttl=600 -# -cut=/usr/bin/cut -getent=/usr/bin/getent -rpc_pipefs=/var/lib/nfs/rpc_pipefs -# -die() -{ - echo "Usage: $0 cache_name entry_name" - exit 1 -} - -[ $# -lt 2 ] && die -cachename="$1" -cache_path=${rpc_pipefs}/cache/${cachename}/channel - -case "${cachename}" in - dns_resolve) - name="$2" - result="$(${getent} hosts ${name} | ${cut} -f1 -d\ )" - [ -z "${result}" ] && result="0" - ;; - *) - die - ;; -esac -echo "${result} ${name} ${ttl}" >${cache_path} - -- cgit v1.2.3-59-g8ed1b From f9a9349846f92b2dabd26cef1f3873e346ba8c1b Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:24 -0300 Subject: Documentation: nfsroot.txt: convert to ReST Convert nfsroot.txt to RST and move it to admin-guide. Content remains mostly the same. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/442d35917351f5260dd8ed7362e9b5f1264ef8ad.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + Documentation/admin-guide/nfs/nfsroot.rst | 363 ++++++++++++++++++++++++++++++ Documentation/filesystems/nfs/nfsroot.txt | 355 ----------------------------- 3 files changed, 364 insertions(+), 355 deletions(-) create mode 100644 Documentation/admin-guide/nfs/nfsroot.rst delete mode 100644 Documentation/filesystems/nfs/nfsroot.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index 2fe77091c25c..ea780cda5549 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -6,3 +6,4 @@ NFS :maxdepth: 1 nfs-client + nfsroot diff --git a/Documentation/admin-guide/nfs/nfsroot.rst b/Documentation/admin-guide/nfs/nfsroot.rst new file mode 100644 index 000000000000..9249be637833 --- /dev/null +++ b/Documentation/admin-guide/nfs/nfsroot.rst @@ -0,0 +1,363 @@ +=============================================== +Mounting the root filesystem via NFS (nfsroot) +=============================================== + +:Authors: + Written 1996 by Gero Kuhlmann + + Updated 1997 by Martin Mares + + Updated 2006 by Nico Schottelius + + Updated 2006 by Horms + + Updated 2018 by Chris Novakovic + + + +In order to use a diskless system, such as an X-terminal or printer server +for example, it is necessary for the root filesystem to be present on a +non-disk device. This may be an initramfs (see Documentation/filesystems/ramfs-rootfs-initramfs.txt), +a ramdisk (see Documentation/admin-guide/initrd.rst) or a +filesystem mounted via NFS. The following text describes on how to use NFS +for the root filesystem. For the rest of this text 'client' means the +diskless system, and 'server' means the NFS server. + + + + +Enabling nfsroot capabilities +============================= + +In order to use nfsroot, NFS client support needs to be selected as +built-in during configuration. Once this has been selected, the nfsroot +option will become available, which should also be selected. + +In the networking options, kernel level autoconfiguration can be selected, +along with the types of autoconfiguration to support. Selecting all of +DHCP, BOOTP and RARP is safe. + + + + +Kernel command line +=================== + +When the kernel has been loaded by a boot loader (see below) it needs to be +told what root fs device to use. And in the case of nfsroot, where to find +both the server and the name of the directory on the server to mount as root. +This can be established using the following kernel command line parameters: + + +root=/dev/nfs + This is necessary to enable the pseudo-NFS-device. Note that it's not a + real device but just a synonym to tell the kernel to use NFS instead of + a real device. + + +nfsroot=[:][,] + If the `nfsroot' parameter is NOT given on the command line, + the default ``"/tftpboot/%s"`` will be used. + + Specifies the IP address of the NFS server. + The default address is determined by the ip parameter + (see below). This parameter allows the use of different + servers for IP autoconfiguration and NFS. + + Name of the directory on the server to mount as root. + If there is a "%s" token in the string, it will be + replaced by the ASCII-representation of the client's + IP address. + + Standard NFS options. All options are separated by commas. + The following defaults are used:: + + port = as given by server portmap daemon + rsize = 4096 + wsize = 4096 + timeo = 7 + retrans = 3 + acregmin = 3 + acregmax = 60 + acdirmin = 30 + acdirmax = 60 + flags = hard, nointr, noposix, cto, ac + + +ip=::::::::: + This parameter tells the kernel how to configure IP addresses of devices + and also how to set up the IP routing table. It was originally called + nfsaddrs, but now the boot-time IP configuration works independently of + NFS, so it was renamed to ip and the old name remained as an alias for + compatibility reasons. + + If this parameter is missing from the kernel command line, all fields are + assumed to be empty, and the defaults mentioned below apply. In general + this means that the kernel tries to configure everything using + autoconfiguration. + + The parameter can appear alone as the value to the ip + parameter (without all the ':' characters before). If the value is + "ip=off" or "ip=none", no autoconfiguration will take place, otherwise + autoconfiguration will take place. The most common way to use this + is "ip=dhcp". + + IP address of the client. + Default: Determined using autoconfiguration. + + IP address of the NFS server. + If RARP is used to determine + the client address and this parameter is NOT empty only + replies from the specified server are accepted. + + Only required for NFS root. That is autoconfiguration + will not be triggered if it is missing and NFS root is not + in operation. + + Value is exported to /proc/net/pnp with the prefix "bootserver " + (see below). + + Default: Determined using autoconfiguration. + The address of the autoconfiguration server is used. + + IP address of a gateway if the server is on a different subnet. + Default: Determined using autoconfiguration. + + Netmask for local network interface. + If unspecified the netmask is derived from the client IP address + assuming classful addressing. + + Default: Determined using autoconfiguration. + + Name of the client. + If a '.' character is present, anything + before the first '.' is used as the client's hostname, and anything + after it is used as its NIS domain name. May be supplied by + autoconfiguration, but its absence will not trigger autoconfiguration. + If specified and DHCP is used, the user-provided hostname (and NIS + domain name, if present) will be carried in the DHCP request; this + may cause a DNS record to be created or updated for the client. + + Default: Client IP address is used in ASCII notation. + + Name of network device to use. + Default: If the host only has one device, it is used. + Otherwise the device is determined using + autoconfiguration. This is done by sending + autoconfiguration requests out of all devices, + and using the device that received the first reply. + + Method to use for autoconfiguration. + In the case of options + which specify multiple autoconfiguration protocols, + requests are sent using all protocols, and the first one + to reply is used. + + Only autoconfiguration protocols that have been compiled + into the kernel will be used, regardless of the value of + this option:: + + off or none: don't use autoconfiguration + (do static IP assignment instead) + on or any: use any protocol available in the kernel + (default) + dhcp: use DHCP + bootp: use BOOTP + rarp: use RARP + both: use both BOOTP and RARP but not DHCP + (old option kept for backwards compatibility) + + if dhcp is used, the client identifier can be used by following + format "ip=dhcp,client-id-type,client-id-value" + + Default: any + + IP address of primary nameserver. + Value is exported to /proc/net/pnp with the prefix "nameserver " + (see below). + + Default: None if not using autoconfiguration; determined + automatically if using autoconfiguration. + + IP address of secondary nameserver. + See . + + IP address of a Network Time Protocol (NTP) server. + Value is exported to /proc/net/ipconfig/ntp_servers, but is + otherwise unused (see below). + + Default: None if not using autoconfiguration; determined + automatically if using autoconfiguration. + + After configuration (whether manual or automatic) is complete, two files + are created in the following format; lines are omitted if their respective + value is empty following configuration: + + - /proc/net/pnp: + + #PROTO: (depending on configuration method) + domain (if autoconfigured, the DNS domain) + nameserver (primary name server IP) + nameserver (secondary name server IP) + nameserver (tertiary name server IP) + bootserver (NFS server IP) + + - /proc/net/ipconfig/ntp_servers: + + (NTP server IP) + (NTP server IP) + (NTP server IP) + + and (in /proc/net/pnp) and and + (in /proc/net/ipconfig/ntp_servers) are requested during autoconfiguration; + they cannot be specified as part of the "ip=" kernel command line parameter. + + Because the "domain" and "nameserver" options are recognised by DNS + resolvers, /etc/resolv.conf is often linked to /proc/net/pnp on systems + that use an NFS root filesystem. + + Note that the kernel will not synchronise the system time with any NTP + servers it discovers; this is the responsibility of a user space process + (e.g. an initrd/initramfs script that passes the IP addresses listed in + /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real + root filesystem if it is on NFS). + + +nfsrootdebug + This parameter enables debugging messages to appear in the kernel + log at boot time so that administrators can verify that the correct + NFS mount options, server address, and root path are passed to the + NFS client. + + +rdinit= + To specify which file contains the program that starts system + initialization, administrators can use this command line parameter. + The default value of this parameter is "/init". If the specified + file exists and the kernel can execute it, root filesystem related + kernel command line parameters, including 'nfsroot=', are ignored. + + A description of the process of mounting the root file system can be + found in Documentation/driver-api/early-userspace/early_userspace_support.rst + + +Boot Loader +=========== + +To get the kernel into memory different approaches can be used. +They depend on various facilities being available: + + +- Booting from a floppy using syslinux + + When building kernels, an easy way to create a boot floppy that uses + syslinux is to use the zdisk or bzdisk make targets which use zimage + and bzimage images respectively. Both targets accept the + FDARGS parameter which can be used to set the kernel command line. + + e.g:: + + make bzdisk FDARGS="root=/dev/nfs" + + Note that the user running this command will need to have + access to the floppy drive device, /dev/fd0 + + For more information on syslinux, including how to create bootdisks + for prebuilt kernels, see http://syslinux.zytor.com/ + + .. note:: + Previously it was possible to write a kernel directly to + a floppy using dd, configure the boot device using rdev, and + boot using the resulting floppy. Linux no longer supports this + method of booting. + +- Booting from a cdrom using isolinux + + When building kernels, an easy way to create a bootable cdrom that + uses isolinux is to use the isoimage target which uses a bzimage + image. Like zdisk and bzdisk, this target accepts the FDARGS + parameter which can be used to set the kernel command line. + + e.g:: + + make isoimage FDARGS="root=/dev/nfs" + + The resulting iso image will be arch//boot/image.iso + This can be written to a cdrom using a variety of tools including + cdrecord. + + e.g:: + + cdrecord dev=ATAPI:1,0,0 arch/x86/boot/image.iso + + For more information on isolinux, including how to create bootdisks + for prebuilt kernels, see http://syslinux.zytor.com/ + +- Using LILO + + When using LILO all the necessary command line parameters may be + specified using the 'append=' directive in the LILO configuration + file. + + However, to use the 'root=' directive you also need to create + a dummy root device, which may be removed after LILO is run. + + e.g:: + + mknod /dev/boot255 c 0 255 + + For information on configuring LILO, please refer to its documentation. + +- Using GRUB + + When using GRUB, kernel parameter are simply appended after the kernel + specification: kernel + +- Using loadlin + + loadlin may be used to boot Linux from a DOS command prompt without + requiring a local hard disk to mount as root. This has not been + thoroughly tested by the authors of this document, but in general + it should be possible configure the kernel command line similarly + to the configuration of LILO. + + Please refer to the loadlin documentation for further information. + +- Using a boot ROM + + This is probably the most elegant way of booting a diskless client. + With a boot ROM the kernel is loaded using the TFTP protocol. The + authors of this document are not aware of any no commercial boot + ROMs that support booting Linux over the network. However, there + are two free implementations of a boot ROM, netboot-nfs and + etherboot, both of which are available on sunsite.unc.edu, and both + of which contain everything you need to boot a diskless Linux client. + +- Using pxelinux + + Pxelinux may be used to boot linux using the PXE boot loader + which is present on many modern network cards. + + When using pxelinux, the kernel image is specified using + "kernel ". The nfsroot parameters + are passed to the kernel by adding them to the "append" line. + It is common to use serial console in conjunction with pxeliunx, + see Documentation/admin-guide/serial-console.rst for more information. + + For more information on isolinux, including how to create bootdisks + for prebuilt kernels, see http://syslinux.zytor.com/ + + + + +Credits +======= + + The nfsroot code in the kernel and the RARP support have been written + by Gero Kuhlmann . + + The rest of the IP layer autoconfiguration code has been written + by Martin Mares . + + In order to write the initial version of nfsroot I would like to thank + Jens-Uwe Mager for his help. diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt deleted file mode 100644 index ae4332464560..000000000000 --- a/Documentation/filesystems/nfs/nfsroot.txt +++ /dev/null @@ -1,355 +0,0 @@ -Mounting the root filesystem via NFS (nfsroot) -=============================================== - -Written 1996 by Gero Kuhlmann -Updated 1997 by Martin Mares -Updated 2006 by Nico Schottelius -Updated 2006 by Horms -Updated 2018 by Chris Novakovic - - - -In order to use a diskless system, such as an X-terminal or printer server -for example, it is necessary for the root filesystem to be present on a -non-disk device. This may be an initramfs (see Documentation/filesystems/ -ramfs-rootfs-initramfs.txt), a ramdisk (see Documentation/admin-guide/initrd.rst) or a -filesystem mounted via NFS. The following text describes on how to use NFS -for the root filesystem. For the rest of this text 'client' means the -diskless system, and 'server' means the NFS server. - - - - -1.) Enabling nfsroot capabilities - ----------------------------- - -In order to use nfsroot, NFS client support needs to be selected as -built-in during configuration. Once this has been selected, the nfsroot -option will become available, which should also be selected. - -In the networking options, kernel level autoconfiguration can be selected, -along with the types of autoconfiguration to support. Selecting all of -DHCP, BOOTP and RARP is safe. - - - - -2.) Kernel command line - ------------------- - -When the kernel has been loaded by a boot loader (see below) it needs to be -told what root fs device to use. And in the case of nfsroot, where to find -both the server and the name of the directory on the server to mount as root. -This can be established using the following kernel command line parameters: - - -root=/dev/nfs - - This is necessary to enable the pseudo-NFS-device. Note that it's not a - real device but just a synonym to tell the kernel to use NFS instead of - a real device. - - -nfsroot=[:][,] - - If the `nfsroot' parameter is NOT given on the command line, - the default "/tftpboot/%s" will be used. - - Specifies the IP address of the NFS server. - The default address is determined by the `ip' parameter - (see below). This parameter allows the use of different - servers for IP autoconfiguration and NFS. - - Name of the directory on the server to mount as root. - If there is a "%s" token in the string, it will be - replaced by the ASCII-representation of the client's - IP address. - - Standard NFS options. All options are separated by commas. - The following defaults are used: - port = as given by server portmap daemon - rsize = 4096 - wsize = 4096 - timeo = 7 - retrans = 3 - acregmin = 3 - acregmax = 60 - acdirmin = 30 - acdirmax = 60 - flags = hard, nointr, noposix, cto, ac - - -ip=::::::: - :: - - This parameter tells the kernel how to configure IP addresses of devices - and also how to set up the IP routing table. It was originally called - `nfsaddrs', but now the boot-time IP configuration works independently of - NFS, so it was renamed to `ip' and the old name remained as an alias for - compatibility reasons. - - If this parameter is missing from the kernel command line, all fields are - assumed to be empty, and the defaults mentioned below apply. In general - this means that the kernel tries to configure everything using - autoconfiguration. - - The parameter can appear alone as the value to the `ip' - parameter (without all the ':' characters before). If the value is - "ip=off" or "ip=none", no autoconfiguration will take place, otherwise - autoconfiguration will take place. The most common way to use this - is "ip=dhcp". - - IP address of the client. - - Default: Determined using autoconfiguration. - - IP address of the NFS server. If RARP is used to determine - the client address and this parameter is NOT empty only - replies from the specified server are accepted. - - Only required for NFS root. That is autoconfiguration - will not be triggered if it is missing and NFS root is not - in operation. - - Value is exported to /proc/net/pnp with the prefix "bootserver " - (see below). - - Default: Determined using autoconfiguration. - The address of the autoconfiguration server is used. - - IP address of a gateway if the server is on a different subnet. - - Default: Determined using autoconfiguration. - - Netmask for local network interface. If unspecified - the netmask is derived from the client IP address assuming - classful addressing. - - Default: Determined using autoconfiguration. - - Name of the client. If a '.' character is present, anything - before the first '.' is used as the client's hostname, and anything - after it is used as its NIS domain name. May be supplied by - autoconfiguration, but its absence will not trigger autoconfiguration. - If specified and DHCP is used, the user-provided hostname (and NIS - domain name, if present) will be carried in the DHCP request; this - may cause a DNS record to be created or updated for the client. - - Default: Client IP address is used in ASCII notation. - - Name of network device to use. - - Default: If the host only has one device, it is used. - Otherwise the device is determined using - autoconfiguration. This is done by sending - autoconfiguration requests out of all devices, - and using the device that received the first reply. - - Method to use for autoconfiguration. In the case of options - which specify multiple autoconfiguration protocols, - requests are sent using all protocols, and the first one - to reply is used. - - Only autoconfiguration protocols that have been compiled - into the kernel will be used, regardless of the value of - this option. - - off or none: don't use autoconfiguration - (do static IP assignment instead) - on or any: use any protocol available in the kernel - (default) - dhcp: use DHCP - bootp: use BOOTP - rarp: use RARP - both: use both BOOTP and RARP but not DHCP - (old option kept for backwards compatibility) - - if dhcp is used, the client identifier can be used by following - format "ip=dhcp,client-id-type,client-id-value" - - Default: any - - IP address of primary nameserver. - Value is exported to /proc/net/pnp with the prefix "nameserver " - (see below). - - Default: None if not using autoconfiguration; determined - automatically if using autoconfiguration. - - IP address of secondary nameserver. - See . - - IP address of a Network Time Protocol (NTP) server. - Value is exported to /proc/net/ipconfig/ntp_servers, but is - otherwise unused (see below). - - Default: None if not using autoconfiguration; determined - automatically if using autoconfiguration. - - After configuration (whether manual or automatic) is complete, two files - are created in the following format; lines are omitted if their respective - value is empty following configuration: - - - /proc/net/pnp: - - #PROTO: (depending on configuration method) - domain (if autoconfigured, the DNS domain) - nameserver (primary name server IP) - nameserver (secondary name server IP) - nameserver (tertiary name server IP) - bootserver (NFS server IP) - - - /proc/net/ipconfig/ntp_servers: - - (NTP server IP) - (NTP server IP) - (NTP server IP) - - and (in /proc/net/pnp) and and - (in /proc/net/ipconfig/ntp_servers) are requested during autoconfiguration; - they cannot be specified as part of the "ip=" kernel command line parameter. - - Because the "domain" and "nameserver" options are recognised by DNS - resolvers, /etc/resolv.conf is often linked to /proc/net/pnp on systems - that use an NFS root filesystem. - - Note that the kernel will not synchronise the system time with any NTP - servers it discovers; this is the responsibility of a user space process - (e.g. an initrd/initramfs script that passes the IP addresses listed in - /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real - root filesystem if it is on NFS). - - -nfsrootdebug - - This parameter enables debugging messages to appear in the kernel - log at boot time so that administrators can verify that the correct - NFS mount options, server address, and root path are passed to the - NFS client. - - -rdinit= - - To specify which file contains the program that starts system - initialization, administrators can use this command line parameter. - The default value of this parameter is "/init". If the specified - file exists and the kernel can execute it, root filesystem related - kernel command line parameters, including `nfsroot=', are ignored. - - A description of the process of mounting the root file system can be - found in: - - Documentation/driver-api/early-userspace/early_userspace_support.rst - - - - -3.) Boot Loader - ---------- - -To get the kernel into memory different approaches can be used. -They depend on various facilities being available: - - -3.1) Booting from a floppy using syslinux - - When building kernels, an easy way to create a boot floppy that uses - syslinux is to use the zdisk or bzdisk make targets which use zimage - and bzimage images respectively. Both targets accept the - FDARGS parameter which can be used to set the kernel command line. - - e.g. - make bzdisk FDARGS="root=/dev/nfs" - - Note that the user running this command will need to have - access to the floppy drive device, /dev/fd0 - - For more information on syslinux, including how to create bootdisks - for prebuilt kernels, see http://syslinux.zytor.com/ - - N.B: Previously it was possible to write a kernel directly to - a floppy using dd, configure the boot device using rdev, and - boot using the resulting floppy. Linux no longer supports this - method of booting. - -3.2) Booting from a cdrom using isolinux - - When building kernels, an easy way to create a bootable cdrom that - uses isolinux is to use the isoimage target which uses a bzimage - image. Like zdisk and bzdisk, this target accepts the FDARGS - parameter which can be used to set the kernel command line. - - e.g. - make isoimage FDARGS="root=/dev/nfs" - - The resulting iso image will be arch//boot/image.iso - This can be written to a cdrom using a variety of tools including - cdrecord. - - e.g. - cdrecord dev=ATAPI:1,0,0 arch/x86/boot/image.iso - - For more information on isolinux, including how to create bootdisks - for prebuilt kernels, see http://syslinux.zytor.com/ - -3.2) Using LILO - When using LILO all the necessary command line parameters may be - specified using the 'append=' directive in the LILO configuration - file. - - However, to use the 'root=' directive you also need to create - a dummy root device, which may be removed after LILO is run. - - mknod /dev/boot255 c 0 255 - - For information on configuring LILO, please refer to its documentation. - -3.3) Using GRUB - When using GRUB, kernel parameter are simply appended after the kernel - specification: kernel - -3.4) Using loadlin - loadlin may be used to boot Linux from a DOS command prompt without - requiring a local hard disk to mount as root. This has not been - thoroughly tested by the authors of this document, but in general - it should be possible configure the kernel command line similarly - to the configuration of LILO. - - Please refer to the loadlin documentation for further information. - -3.5) Using a boot ROM - This is probably the most elegant way of booting a diskless client. - With a boot ROM the kernel is loaded using the TFTP protocol. The - authors of this document are not aware of any no commercial boot - ROMs that support booting Linux over the network. However, there - are two free implementations of a boot ROM, netboot-nfs and - etherboot, both of which are available on sunsite.unc.edu, and both - of which contain everything you need to boot a diskless Linux client. - -3.6) Using pxelinux - Pxelinux may be used to boot linux using the PXE boot loader - which is present on many modern network cards. - - When using pxelinux, the kernel image is specified using - "kernel ". The nfsroot parameters - are passed to the kernel by adding them to the "append" line. - It is common to use serial console in conjunction with pxeliunx, - see Documentation/admin-guide/serial-console.rst for more information. - - For more information on isolinux, including how to create bootdisks - for prebuilt kernels, see http://syslinux.zytor.com/ - - - - -4.) Credits - ------- - - The nfsroot code in the kernel and the RARP support have been written - by Gero Kuhlmann . - - The rest of the IP layer autoconfiguration code has been written - by Martin Mares . - - In order to write the initial version of nfsroot I would like to thank - Jens-Uwe Mager for his help. -- cgit v1.2.3-59-g8ed1b From 0867fb07fa320ea254f4fc90cb609a510a2f65bb Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:25 -0300 Subject: Documentation: nfsroot.rst: COSMETIC: refill a paragraph Refill a paragraph to eliminate long lines. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/58c50f6ba94a0a2f212c4d2a42f64ffb40336b68.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/nfsroot.rst | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/nfsroot.rst b/Documentation/admin-guide/nfs/nfsroot.rst index 9249be637833..82a4fda057f9 100644 --- a/Documentation/admin-guide/nfs/nfsroot.rst +++ b/Documentation/admin-guide/nfs/nfsroot.rst @@ -15,13 +15,14 @@ Mounting the root filesystem via NFS (nfsroot) -In order to use a diskless system, such as an X-terminal or printer server -for example, it is necessary for the root filesystem to be present on a -non-disk device. This may be an initramfs (see Documentation/filesystems/ramfs-rootfs-initramfs.txt), -a ramdisk (see Documentation/admin-guide/initrd.rst) or a -filesystem mounted via NFS. The following text describes on how to use NFS -for the root filesystem. For the rest of this text 'client' means the -diskless system, and 'server' means the NFS server. +In order to use a diskless system, such as an X-terminal or printer server for +example, it is necessary for the root filesystem to be present on a non-disk +device. This may be an initramfs (see +Documentation/filesystems/ramfs-rootfs-initramfs.txt), a ramdisk (see +Documentation/admin-guide/initrd.rst) or a filesystem mounted via NFS. The +following text describes on how to use NFS for the root filesystem. For the rest +of this text 'client' means the diskless system, and 'server' means the NFS +server. -- cgit v1.2.3-59-g8ed1b From f8b8d030597a3b0a20e9cc2e958f82164690fbdb Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:26 -0300 Subject: Documentation: nfs-rdma: convert to ReST Convert nfs-rdma to ReST and move it to admin-guide. Content remais mostly untouched. Also, mark the doc as obsolete. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/9c88f184f9de2a3eb5181563e258559efc02f58a.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + Documentation/admin-guide/nfs/nfs-rdma.rst | 292 +++++++++++++++++++++++++++++ Documentation/filesystems/nfs/nfs-rdma.txt | 274 --------------------------- 3 files changed, 293 insertions(+), 274 deletions(-) create mode 100644 Documentation/admin-guide/nfs/nfs-rdma.rst delete mode 100644 Documentation/filesystems/nfs/nfs-rdma.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index ea780cda5549..875a96fe9d04 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -7,3 +7,4 @@ NFS nfs-client nfsroot + nfs-rdma diff --git a/Documentation/admin-guide/nfs/nfs-rdma.rst b/Documentation/admin-guide/nfs/nfs-rdma.rst new file mode 100644 index 000000000000..ef0f3678b1fb --- /dev/null +++ b/Documentation/admin-guide/nfs/nfs-rdma.rst @@ -0,0 +1,292 @@ +=================== +Setting up NFS/RDMA +=================== + +:Author: + NetApp and Open Grid Computing (May 29, 2008) + +.. warning:: + This document is probably obsolete. + +Overview +======== + +This document describes how to install and setup the Linux NFS/RDMA client +and server software. + +The NFS/RDMA client was first included in Linux 2.6.24. The NFS/RDMA server +was first included in the following release, Linux 2.6.25. + +In our testing, we have obtained excellent performance results (full 10Gbit +wire bandwidth at minimal client CPU) under many workloads. The code passes +the full Connectathon test suite and operates over both Infiniband and iWARP +RDMA adapters. + +Getting Help +============ + +If you get stuck, you can ask questions on the +nfs-rdma-devel@lists.sourceforge.net mailing list. + +Installation +============ + +These instructions are a step by step guide to building a machine for +use with NFS/RDMA. + +- Install an RDMA device + + Any device supported by the drivers in drivers/infiniband/hw is acceptable. + + Testing has been performed using several Mellanox-based IB cards, the + Ammasso AMS1100 iWARP adapter, and the Chelsio cxgb3 iWARP adapter. + +- Install a Linux distribution and tools + + The first kernel release to contain both the NFS/RDMA client and server was + Linux 2.6.25 Therefore, a distribution compatible with this and subsequent + Linux kernel release should be installed. + + The procedures described in this document have been tested with + distributions from Red Hat's Fedora Project (http://fedora.redhat.com/). + +- Install nfs-utils-1.1.2 or greater on the client + + An NFS/RDMA mount point can be obtained by using the mount.nfs command in + nfs-utils-1.1.2 or greater (nfs-utils-1.1.1 was the first nfs-utils + version with support for NFS/RDMA mounts, but for various reasons we + recommend using nfs-utils-1.1.2 or greater). To see which version of + mount.nfs you are using, type: + + .. code-block:: sh + + $ /sbin/mount.nfs -V + + If the version is less than 1.1.2 or the command does not exist, + you should install the latest version of nfs-utils. + + Download the latest package from: http://www.kernel.org/pub/linux/utils/nfs + + Uncompress the package and follow the installation instructions. + + If you will not need the idmapper and gssd executables (you do not need + these to create an NFS/RDMA enabled mount command), the installation + process can be simplified by disabling these features when running + configure: + + .. code-block:: sh + + $ ./configure --disable-gss --disable-nfsv4 + + To build nfs-utils you will need the tcp_wrappers package installed. For + more information on this see the package's README and INSTALL files. + + After building the nfs-utils package, there will be a mount.nfs binary in + the utils/mount directory. This binary can be used to initiate NFS v2, v3, + or v4 mounts. To initiate a v4 mount, the binary must be called + mount.nfs4. The standard technique is to create a symlink called + mount.nfs4 to mount.nfs. + + This mount.nfs binary should be installed at /sbin/mount.nfs as follows: + + .. code-block:: sh + + $ sudo cp utils/mount/mount.nfs /sbin/mount.nfs + + In this location, mount.nfs will be invoked automatically for NFS mounts + by the system mount command. + + .. note:: + mount.nfs and therefore nfs-utils-1.1.2 or greater is only needed + on the NFS client machine. You do not need this specific version of + nfs-utils on the server. Furthermore, only the mount.nfs command from + nfs-utils-1.1.2 is needed on the client. + +- Install a Linux kernel with NFS/RDMA + + The NFS/RDMA client and server are both included in the mainline Linux + kernel version 2.6.25 and later. This and other versions of the Linux + kernel can be found at: https://www.kernel.org/pub/linux/kernel/ + + Download the sources and place them in an appropriate location. + +- Configure the RDMA stack + + Make sure your kernel configuration has RDMA support enabled. Under + Device Drivers -> InfiniBand support, update the kernel configuration + to enable InfiniBand support [NOTE: the option name is misleading. Enabling + InfiniBand support is required for all RDMA devices (IB, iWARP, etc.)]. + + Enable the appropriate IB HCA support (mlx4, mthca, ehca, ipath, etc.) or + iWARP adapter support (amso, cxgb3, etc.). + + If you are using InfiniBand, be sure to enable IP-over-InfiniBand support. + +- Configure the NFS client and server + + Your kernel configuration must also have NFS file system support and/or + NFS server support enabled. These and other NFS related configuration + options can be found under File Systems -> Network File Systems. + +- Build, install, reboot + + The NFS/RDMA code will be enabled automatically if NFS and RDMA + are turned on. The NFS/RDMA client and server are configured via the hidden + SUNRPC_XPRT_RDMA config option that depends on SUNRPC and INFINIBAND. The + value of SUNRPC_XPRT_RDMA will be: + + #. N if either SUNRPC or INFINIBAND are N, in this case the NFS/RDMA client + and server will not be built + + #. M if both SUNRPC and INFINIBAND are on (M or Y) and at least one is M, + in this case the NFS/RDMA client and server will be built as modules + + #. Y if both SUNRPC and INFINIBAND are Y, in this case the NFS/RDMA client + and server will be built into the kernel + + Therefore, if you have followed the steps above and turned no NFS and RDMA, + the NFS/RDMA client and server will be built. + + Build a new kernel, install it, boot it. + +Check RDMA and NFS Setup +======================== + +Before configuring the NFS/RDMA software, it is a good idea to test +your new kernel to ensure that the kernel is working correctly. +In particular, it is a good idea to verify that the RDMA stack +is functioning as expected and standard NFS over TCP/IP and/or UDP/IP +is working properly. + +- Check RDMA Setup + + If you built the RDMA components as modules, load them at + this time. For example, if you are using a Mellanox Tavor/Sinai/Arbel + card: + + .. code-block:: sh + + $ modprobe ib_mthca + $ modprobe ib_ipoib + + If you are using InfiniBand, make sure there is a Subnet Manager (SM) + running on the network. If your IB switch has an embedded SM, you can + use it. Otherwise, you will need to run an SM, such as OpenSM, on one + of your end nodes. + + If an SM is running on your network, you should see the following: + + .. code-block:: sh + + $ cat /sys/class/infiniband/driverX/ports/1/state + 4: ACTIVE + + where driverX is mthca0, ipath5, ehca3, etc. + + To further test the InfiniBand software stack, use IPoIB (this + assumes you have two IB hosts named host1 and host2): + + .. code-block:: sh + + host1$ ip link set dev ib0 up + host1$ ip address add dev ib0 a.b.c.x + host2$ ip link set dev ib0 up + host2$ ip address add dev ib0 a.b.c.y + host1$ ping a.b.c.y + host2$ ping a.b.c.x + + For other device types, follow the appropriate procedures. + +- Check NFS Setup + + For the NFS components enabled above (client and/or server), + test their functionality over standard Ethernet using TCP/IP or UDP/IP. + +NFS/RDMA Setup +============== + +We recommend that you use two machines, one to act as the client and +one to act as the server. + +One time configuration: +----------------------- + +- On the server system, configure the /etc/exports file and start the NFS/RDMA server. + + Exports entries with the following formats have been tested:: + + /vol0 192.168.0.47(fsid=0,rw,async,insecure,no_root_squash) + /vol0 192.168.0.0/255.255.255.0(fsid=0,rw,async,insecure,no_root_squash) + + The IP address(es) is(are) the client's IPoIB address for an InfiniBand + HCA or the client's iWARP address(es) for an RNIC. + + .. note:: + The "insecure" option must be used because the NFS/RDMA client does + not use a reserved port. + +Each time a machine boots: +-------------------------- + +- Load and configure the RDMA drivers + + For InfiniBand using a Mellanox adapter: + + .. code-block:: sh + + $ modprobe ib_mthca + $ modprobe ib_ipoib + $ ip li set dev ib0 up + $ ip addr add dev ib0 a.b.c.d + + .. note:: + Please use unique addresses for the client and server! + +- Start the NFS server + + If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in + kernel config), load the RDMA transport module: + + .. code-block:: sh + + $ modprobe svcrdma + + Regardless of how the server was built (module or built-in), start the + server: + + .. code-block:: sh + + $ /etc/init.d/nfs start + + or + + .. code-block:: sh + + $ service nfs start + + Instruct the server to listen on the RDMA transport: + + .. code-block:: sh + + $ echo rdma 20049 > /proc/fs/nfsd/portlist + +- On the client system + + If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in + kernel config), load the RDMA client module: + + .. code-block:: sh + + $ modprobe xprtrdma.ko + + Regardless of how the client was built (module or built-in), use this + command to mount the NFS/RDMA server: + + .. code-block:: sh + + $ mount -o rdma,port=20049 :/ /mnt + + To verify that the mount is using RDMA, run "cat /proc/mounts" and check + the "proto" field for the given mount. + + Congratulations! You're using NFS/RDMA! diff --git a/Documentation/filesystems/nfs/nfs-rdma.txt b/Documentation/filesystems/nfs/nfs-rdma.txt deleted file mode 100644 index 22dc0dd6889c..000000000000 --- a/Documentation/filesystems/nfs/nfs-rdma.txt +++ /dev/null @@ -1,274 +0,0 @@ -################################################################################ -# # -# NFS/RDMA README # -# # -################################################################################ - - Author: NetApp and Open Grid Computing - Date: May 29, 2008 - -Table of Contents -~~~~~~~~~~~~~~~~~ - - Overview - - Getting Help - - Installation - - Check RDMA and NFS Setup - - NFS/RDMA Setup - -Overview -~~~~~~~~ - - This document describes how to install and setup the Linux NFS/RDMA client - and server software. - - The NFS/RDMA client was first included in Linux 2.6.24. The NFS/RDMA server - was first included in the following release, Linux 2.6.25. - - In our testing, we have obtained excellent performance results (full 10Gbit - wire bandwidth at minimal client CPU) under many workloads. The code passes - the full Connectathon test suite and operates over both Infiniband and iWARP - RDMA adapters. - -Getting Help -~~~~~~~~~~~~ - - If you get stuck, you can ask questions on the - - nfs-rdma-devel@lists.sourceforge.net - - mailing list. - -Installation -~~~~~~~~~~~~ - - These instructions are a step by step guide to building a machine for - use with NFS/RDMA. - - - Install an RDMA device - - Any device supported by the drivers in drivers/infiniband/hw is acceptable. - - Testing has been performed using several Mellanox-based IB cards, the - Ammasso AMS1100 iWARP adapter, and the Chelsio cxgb3 iWARP adapter. - - - Install a Linux distribution and tools - - The first kernel release to contain both the NFS/RDMA client and server was - Linux 2.6.25 Therefore, a distribution compatible with this and subsequent - Linux kernel release should be installed. - - The procedures described in this document have been tested with - distributions from Red Hat's Fedora Project (http://fedora.redhat.com/). - - - Install nfs-utils-1.1.2 or greater on the client - - An NFS/RDMA mount point can be obtained by using the mount.nfs command in - nfs-utils-1.1.2 or greater (nfs-utils-1.1.1 was the first nfs-utils - version with support for NFS/RDMA mounts, but for various reasons we - recommend using nfs-utils-1.1.2 or greater). To see which version of - mount.nfs you are using, type: - - $ /sbin/mount.nfs -V - - If the version is less than 1.1.2 or the command does not exist, - you should install the latest version of nfs-utils. - - Download the latest package from: - - http://www.kernel.org/pub/linux/utils/nfs - - Uncompress the package and follow the installation instructions. - - If you will not need the idmapper and gssd executables (you do not need - these to create an NFS/RDMA enabled mount command), the installation - process can be simplified by disabling these features when running - configure: - - $ ./configure --disable-gss --disable-nfsv4 - - To build nfs-utils you will need the tcp_wrappers package installed. For - more information on this see the package's README and INSTALL files. - - After building the nfs-utils package, there will be a mount.nfs binary in - the utils/mount directory. This binary can be used to initiate NFS v2, v3, - or v4 mounts. To initiate a v4 mount, the binary must be called - mount.nfs4. The standard technique is to create a symlink called - mount.nfs4 to mount.nfs. - - This mount.nfs binary should be installed at /sbin/mount.nfs as follows: - - $ sudo cp utils/mount/mount.nfs /sbin/mount.nfs - - In this location, mount.nfs will be invoked automatically for NFS mounts - by the system mount command. - - NOTE: mount.nfs and therefore nfs-utils-1.1.2 or greater is only needed - on the NFS client machine. You do not need this specific version of - nfs-utils on the server. Furthermore, only the mount.nfs command from - nfs-utils-1.1.2 is needed on the client. - - - Install a Linux kernel with NFS/RDMA - - The NFS/RDMA client and server are both included in the mainline Linux - kernel version 2.6.25 and later. This and other versions of the Linux - kernel can be found at: - - https://www.kernel.org/pub/linux/kernel/ - - Download the sources and place them in an appropriate location. - - - Configure the RDMA stack - - Make sure your kernel configuration has RDMA support enabled. Under - Device Drivers -> InfiniBand support, update the kernel configuration - to enable InfiniBand support [NOTE: the option name is misleading. Enabling - InfiniBand support is required for all RDMA devices (IB, iWARP, etc.)]. - - Enable the appropriate IB HCA support (mlx4, mthca, ehca, ipath, etc.) or - iWARP adapter support (amso, cxgb3, etc.). - - If you are using InfiniBand, be sure to enable IP-over-InfiniBand support. - - - Configure the NFS client and server - - Your kernel configuration must also have NFS file system support and/or - NFS server support enabled. These and other NFS related configuration - options can be found under File Systems -> Network File Systems. - - - Build, install, reboot - - The NFS/RDMA code will be enabled automatically if NFS and RDMA - are turned on. The NFS/RDMA client and server are configured via the hidden - SUNRPC_XPRT_RDMA config option that depends on SUNRPC and INFINIBAND. The - value of SUNRPC_XPRT_RDMA will be: - - - N if either SUNRPC or INFINIBAND are N, in this case the NFS/RDMA client - and server will not be built - - M if both SUNRPC and INFINIBAND are on (M or Y) and at least one is M, - in this case the NFS/RDMA client and server will be built as modules - - Y if both SUNRPC and INFINIBAND are Y, in this case the NFS/RDMA client - and server will be built into the kernel - - Therefore, if you have followed the steps above and turned no NFS and RDMA, - the NFS/RDMA client and server will be built. - - Build a new kernel, install it, boot it. - -Check RDMA and NFS Setup -~~~~~~~~~~~~~~~~~~~~~~~~ - - Before configuring the NFS/RDMA software, it is a good idea to test - your new kernel to ensure that the kernel is working correctly. - In particular, it is a good idea to verify that the RDMA stack - is functioning as expected and standard NFS over TCP/IP and/or UDP/IP - is working properly. - - - Check RDMA Setup - - If you built the RDMA components as modules, load them at - this time. For example, if you are using a Mellanox Tavor/Sinai/Arbel - card: - - $ modprobe ib_mthca - $ modprobe ib_ipoib - - If you are using InfiniBand, make sure there is a Subnet Manager (SM) - running on the network. If your IB switch has an embedded SM, you can - use it. Otherwise, you will need to run an SM, such as OpenSM, on one - of your end nodes. - - If an SM is running on your network, you should see the following: - - $ cat /sys/class/infiniband/driverX/ports/1/state - 4: ACTIVE - - where driverX is mthca0, ipath5, ehca3, etc. - - To further test the InfiniBand software stack, use IPoIB (this - assumes you have two IB hosts named host1 and host2): - - host1$ ip link set dev ib0 up - host1$ ip address add dev ib0 a.b.c.x - host2$ ip link set dev ib0 up - host2$ ip address add dev ib0 a.b.c.y - host1$ ping a.b.c.y - host2$ ping a.b.c.x - - For other device types, follow the appropriate procedures. - - - Check NFS Setup - - For the NFS components enabled above (client and/or server), - test their functionality over standard Ethernet using TCP/IP or UDP/IP. - -NFS/RDMA Setup -~~~~~~~~~~~~~~ - - We recommend that you use two machines, one to act as the client and - one to act as the server. - - One time configuration: - - - On the server system, configure the /etc/exports file and - start the NFS/RDMA server. - - Exports entries with the following formats have been tested: - - /vol0 192.168.0.47(fsid=0,rw,async,insecure,no_root_squash) - /vol0 192.168.0.0/255.255.255.0(fsid=0,rw,async,insecure,no_root_squash) - - The IP address(es) is(are) the client's IPoIB address for an InfiniBand - HCA or the client's iWARP address(es) for an RNIC. - - NOTE: The "insecure" option must be used because the NFS/RDMA client does - not use a reserved port. - - Each time a machine boots: - - - Load and configure the RDMA drivers - - For InfiniBand using a Mellanox adapter: - - $ modprobe ib_mthca - $ modprobe ib_ipoib - $ ip li set dev ib0 up - $ ip addr add dev ib0 a.b.c.d - - NOTE: use unique addresses for the client and server - - - Start the NFS server - - If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in - kernel config), load the RDMA transport module: - - $ modprobe svcrdma - - Regardless of how the server was built (module or built-in), start the - server: - - $ /etc/init.d/nfs start - - or - - $ service nfs start - - Instruct the server to listen on the RDMA transport: - - $ echo rdma 20049 > /proc/fs/nfsd/portlist - - - On the client system - - If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in - kernel config), load the RDMA client module: - - $ modprobe xprtrdma.ko - - Regardless of how the client was built (module or built-in), use this - command to mount the NFS/RDMA server: - - $ mount -o rdma,port=20049 :/ /mnt - - To verify that the mount is using RDMA, run "cat /proc/mounts" and check - the "proto" field for the given mount. - - Congratulations! You're using NFS/RDMA! -- cgit v1.2.3-59-g8ed1b From 0f3456ba9fb61584a891fb5264cf09e4d5fe0741 Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:27 -0300 Subject: Documentation: convert nfsd-admin-interfaces to ReST Convert nfsd-admin-interfaces to ReST and move it into admin-guide. Content remains mostly untouched. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/d471305e9c96dec38f18d2ff816fca2269a88e29.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + .../admin-guide/nfs/nfsd-admin-interfaces.rst | 40 +++++++++++++++++++++ .../filesystems/nfs/nfsd-admin-interfaces.txt | 41 ---------------------- 3 files changed, 41 insertions(+), 41 deletions(-) create mode 100644 Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst delete mode 100644 Documentation/filesystems/nfs/nfsd-admin-interfaces.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index 875a96fe9d04..e0b2f4260ad7 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -8,3 +8,4 @@ NFS nfs-client nfsroot nfs-rdma + nfsd-admin-interfaces diff --git a/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst b/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst new file mode 100644 index 000000000000..c05926f79054 --- /dev/null +++ b/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst @@ -0,0 +1,40 @@ +================================== +Administrative interfaces for nfsd +================================== + +Note that normally these interfaces are used only by the utilities in +nfs-utils. + +nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem, +which is normally mounted at /proc/fs/nfsd/. + +The server is always started by the first write of a nonzero value to +nfsd/threads. + +Before doing that, NFSD can be told which sockets to listen on by +writing to nfsd/portlist; that write may be: + + - an ascii-encoded file descriptor, which should refer to a + bound (and listening, for tcp) socket, or + - "transportname port", where transportname is currently either + "udp", "tcp", or "rdma". + +If nfsd is started without doing any of these, then it will create one +udp and one tcp listener at port 2049 (see nfsd_init_socks). + +On startup, nfsd and lockd grace periods start. nfsd is shut down by a write of +0 to nfsd/threads. All locks and state are thrown away at that point. + +Between startup and shutdown, the number of threads may be adjusted up +or down by additional writes to nfsd/threads or by writes to +nfsd/pool_threads. + +For more detail about files under nfsd/ and what they control, see +fs/nfsd/nfsctl.c; most of them have detailed comments. + +Implementation notes +==================== + +Note that the rpc server requires the caller to serialize addition and +removal of listening sockets, and startup and shutdown of the server. +For nfsd this is done using nfsd_mutex. diff --git a/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt b/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt deleted file mode 100644 index 56a96fb08a73..000000000000 --- a/Documentation/filesystems/nfs/nfsd-admin-interfaces.txt +++ /dev/null @@ -1,41 +0,0 @@ -Administrative interfaces for nfsd -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -Note that normally these interfaces are used only by the utilities in -nfs-utils. - -nfsd is controlled mainly by pseudofiles under the "nfsd" filesystem, -which is normally mounted at /proc/fs/nfsd/. - -The server is always started by the first write of a nonzero value to -nfsd/threads. - -Before doing that, NFSD can be told which sockets to listen on by -writing to nfsd/portlist; that write may be: - - - an ascii-encoded file descriptor, which should refer to a - bound (and listening, for tcp) socket, or - - "transportname port", where transportname is currently either - "udp", "tcp", or "rdma". - -If nfsd is started without doing any of these, then it will create one -udp and one tcp listener at port 2049 (see nfsd_init_socks). - -On startup, nfsd and lockd grace periods start. - -nfsd is shut down by a write of 0 to nfsd/threads. All locks and state -are thrown away at that point. - -Between startup and shutdown, the number of threads may be adjusted up -or down by additional writes to nfsd/threads or by writes to -nfsd/pool_threads. - -For more detail about files under nfsd/ and what they control, see -fs/nfsd/nfsctl.c; most of them have detailed comments. - -Implementation notes -^^^^^^^^^^^^^^^^^^^^ - -Note that the rpc server requires the caller to serialize addition and -removal of listening sockets, and startup and shutdown of the server. -For nfsd this is done using nfsd_mutex. -- cgit v1.2.3-59-g8ed1b From fbdcd0b8e56492dd85bd8d08f15a14334bb59259 Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:28 -0300 Subject: Documentation: nfs: idmapper: convert to ReST Convert idmapper.txt to ReST and move it to admin-guide. Content remains mostly unchanged otherwise. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/069e40cd551ea778538f8fe9ad15ee26e45fc748.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + Documentation/admin-guide/nfs/nfs-idmapper.rst | 78 ++++++++++++++++++++++++++ Documentation/filesystems/nfs/idmapper.txt | 75 ------------------------- 3 files changed, 79 insertions(+), 75 deletions(-) create mode 100644 Documentation/admin-guide/nfs/nfs-idmapper.rst delete mode 100644 Documentation/filesystems/nfs/idmapper.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index e0b2f4260ad7..8376d5225fc2 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -9,3 +9,4 @@ NFS nfsroot nfs-rdma nfsd-admin-interfaces + nfs-idmapper diff --git a/Documentation/admin-guide/nfs/nfs-idmapper.rst b/Documentation/admin-guide/nfs/nfs-idmapper.rst new file mode 100644 index 000000000000..58b8e63412d5 --- /dev/null +++ b/Documentation/admin-guide/nfs/nfs-idmapper.rst @@ -0,0 +1,78 @@ +============= +NFS ID Mapper +============= + +Id mapper is used by NFS to translate user and group ids into names, and to +translate user and group names into ids. Part of this translation involves +performing an upcall to userspace to request the information. There are two +ways NFS could obtain this information: placing a call to /sbin/request-key +or by placing a call to the rpc.idmap daemon. + +NFS will attempt to call /sbin/request-key first. If this succeeds, the +result will be cached using the generic request-key cache. This call should +only fail if /etc/request-key.conf is not configured for the id_resolver key +type, see the "Configuring" section below if you wish to use the request-key +method. + +If the call to /sbin/request-key fails (if /etc/request-key.conf is not +configured with the id_resolver key type), then the idmapper will ask the +legacy rpc.idmap daemon for the id mapping. This result will be stored +in a custom NFS idmap cache. + + +Configuring +=========== + +The file /etc/request-key.conf will need to be modified so /sbin/request-key can +direct the upcall. The following line should be added: + +``#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...`` +``#====== ======= =============== =============== ===============================`` +``create id_resolver * * /usr/sbin/nfs.idmap %k %d 600`` + + +This will direct all id_resolver requests to the program /usr/sbin/nfs.idmap. +The last parameter, 600, defines how many seconds into the future the key will +expire. This parameter is optional for /usr/sbin/nfs.idmap. When the timeout +is not specified, nfs.idmap will default to 600 seconds. + +id mapper uses for key descriptions:: + + uid: Find the UID for the given user + gid: Find the GID for the given group + user: Find the user name for the given UID + group: Find the group name for the given GID + +You can handle any of these individually, rather than using the generic upcall +program. If you would like to use your own program for a uid lookup then you +would edit your request-key.conf so it look similar to this: + +``#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...`` +``#====== ======= =============== =============== ===============================`` +``create id_resolver uid:* * /some/other/program %k %d 600`` +``create id_resolver * * /usr/sbin/nfs.idmap %k %d 600`` + + +Notice that the new line was added above the line for the generic program. +request-key will find the first matching line and corresponding program. In +this case, /some/other/program will handle all uid lookups and +/usr/sbin/nfs.idmap will handle gid, user, and group lookups. + +See Documentation/security/keys/request-key.rst for more information +about the request-key function. + + +nfs.idmap +========= + +nfs.idmap is designed to be called by request-key, and should not be run "by +hand". This program takes two arguments, a serialized key and a key +description. The serialized key is first converted into a key_serial_t, and +then passed as an argument to keyctl_instantiate (both are part of keyutils.h). + +The actual lookups are performed by functions found in nfsidmap.h. nfs.idmap +determines the correct function to call by looking at the first part of the +description string. For example, a uid lookup description will appear as +"uid:user@domain". + +nfs.idmap will return 0 if the key was instantiated, and non-zero otherwise. diff --git a/Documentation/filesystems/nfs/idmapper.txt b/Documentation/filesystems/nfs/idmapper.txt deleted file mode 100644 index b86831acd583..000000000000 --- a/Documentation/filesystems/nfs/idmapper.txt +++ /dev/null @@ -1,75 +0,0 @@ - -========= -ID Mapper -========= -Id mapper is used by NFS to translate user and group ids into names, and to -translate user and group names into ids. Part of this translation involves -performing an upcall to userspace to request the information. There are two -ways NFS could obtain this information: placing a call to /sbin/request-key -or by placing a call to the rpc.idmap daemon. - -NFS will attempt to call /sbin/request-key first. If this succeeds, the -result will be cached using the generic request-key cache. This call should -only fail if /etc/request-key.conf is not configured for the id_resolver key -type, see the "Configuring" section below if you wish to use the request-key -method. - -If the call to /sbin/request-key fails (if /etc/request-key.conf is not -configured with the id_resolver key type), then the idmapper will ask the -legacy rpc.idmap daemon for the id mapping. This result will be stored -in a custom NFS idmap cache. - - -=========== -Configuring -=========== -The file /etc/request-key.conf will need to be modified so /sbin/request-key can -direct the upcall. The following line should be added: - -#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ... -#====== ======= =============== =============== =============================== -create id_resolver * * /usr/sbin/nfs.idmap %k %d 600 - -This will direct all id_resolver requests to the program /usr/sbin/nfs.idmap. -The last parameter, 600, defines how many seconds into the future the key will -expire. This parameter is optional for /usr/sbin/nfs.idmap. When the timeout -is not specified, nfs.idmap will default to 600 seconds. - -id mapper uses for key descriptions: - uid: Find the UID for the given user - gid: Find the GID for the given group - user: Find the user name for the given UID - group: Find the group name for the given GID - -You can handle any of these individually, rather than using the generic upcall -program. If you would like to use your own program for a uid lookup then you -would edit your request-key.conf so it look similar to this: - -#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ... -#====== ======= =============== =============== =============================== -create id_resolver uid:* * /some/other/program %k %d 600 -create id_resolver * * /usr/sbin/nfs.idmap %k %d 600 - -Notice that the new line was added above the line for the generic program. -request-key will find the first matching line and corresponding program. In -this case, /some/other/program will handle all uid lookups and -/usr/sbin/nfs.idmap will handle gid, user, and group lookups. - -See for more information -about the request-key function. - - -========= -nfs.idmap -========= -nfs.idmap is designed to be called by request-key, and should not be run "by -hand". This program takes two arguments, a serialized key and a key -description. The serialized key is first converted into a key_serial_t, and -then passed as an argument to keyctl_instantiate (both are part of keyutils.h). - -The actual lookups are performed by functions found in nfsidmap.h. nfs.idmap -determines the correct function to call by looking at the first part of the -description string. For example, a uid lookup description will appear as -"uid:user@domain". - -nfs.idmap will return 0 if the key was instantiated, and non-zero otherwise. -- cgit v1.2.3-59-g8ed1b From 26f6225fa53dc4ad26b9d9d712c0f55a92eb2c23 Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:29 -0300 Subject: Documentation: nfs: convert pnfs-block-server to ReST Convert pnfs-block-server.txt to ReST and move it to admin-guide. Content remains mostly unchanged. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/c06903760e690c16d9df92f5e75f80381d6326d8.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + .../admin-guide/nfs/pnfs-block-server.rst | 42 ++++++++++++++++++++++ .../filesystems/nfs/pnfs-block-server.txt | 37 ------------------- 3 files changed, 43 insertions(+), 37 deletions(-) create mode 100644 Documentation/admin-guide/nfs/pnfs-block-server.rst delete mode 100644 Documentation/filesystems/nfs/pnfs-block-server.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index 8376d5225fc2..365f42a611a4 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -10,3 +10,4 @@ NFS nfs-rdma nfsd-admin-interfaces nfs-idmapper + pnfs-block-server diff --git a/Documentation/admin-guide/nfs/pnfs-block-server.rst b/Documentation/admin-guide/nfs/pnfs-block-server.rst new file mode 100644 index 000000000000..b00a2e705cc4 --- /dev/null +++ b/Documentation/admin-guide/nfs/pnfs-block-server.rst @@ -0,0 +1,42 @@ +=================================== +pNFS block layout server user guide +=================================== + +The Linux NFS server now supports the pNFS block layout extension. In this +case the NFS server acts as Metadata Server (MDS) for pNFS, which in addition +to handling all the metadata access to the NFS export also hands out layouts +to the clients to directly access the underlying block devices that are +shared with the client. + +To use pNFS block layouts with with the Linux NFS server the exported file +system needs to support the pNFS block layouts (currently just XFS), and the +file system must sit on shared storage (typically iSCSI) that is accessible +to the clients in addition to the MDS. As of now the file system needs to +sit directly on the exported volume, striping or concatenation of +volumes on the MDS and clients is not supported yet. + +On the server, pNFS block volume support is automatically if the file system +support it. On the client make sure the kernel has the CONFIG_PNFS_BLOCK +option enabled, the blkmapd daemon from nfs-utils is running, and the +file system is mounted using the NFSv4.1 protocol version (mount -o vers=4.1). + +If the nfsd server needs to fence a non-responding client it calls +/sbin/nfsd-recall-failed with the first argument set to the IP address of +the client, and the second argument set to the device node without the /dev +prefix for the file system to be fenced. Below is an example file that shows +how to translate the device into a serial number from SCSI EVPD 0x80:: + + cat > /sbin/nfsd-recall-failed << EOF + +.. code-block:: sh + + #!/bin/sh + + CLIENT="$1" + DEV="/dev/$2" + EVPD=`sg_inq --page=0x80 ${DEV} | \ + grep "Unit serial number:" | \ + awk -F ': ' '{print $2}'` + + echo "fencing client ${CLIENT} serial ${EVPD}" >> /var/log/pnfsd-fence.log + EOF diff --git a/Documentation/filesystems/nfs/pnfs-block-server.txt b/Documentation/filesystems/nfs/pnfs-block-server.txt deleted file mode 100644 index 2143673cf154..000000000000 --- a/Documentation/filesystems/nfs/pnfs-block-server.txt +++ /dev/null @@ -1,37 +0,0 @@ -pNFS block layout server user guide - -The Linux NFS server now supports the pNFS block layout extension. In this -case the NFS server acts as Metadata Server (MDS) for pNFS, which in addition -to handling all the metadata access to the NFS export also hands out layouts -to the clients to directly access the underlying block devices that are -shared with the client. - -To use pNFS block layouts with with the Linux NFS server the exported file -system needs to support the pNFS block layouts (currently just XFS), and the -file system must sit on shared storage (typically iSCSI) that is accessible -to the clients in addition to the MDS. As of now the file system needs to -sit directly on the exported volume, striping or concatenation of -volumes on the MDS and clients is not supported yet. - -On the server, pNFS block volume support is automatically if the file system -support it. On the client make sure the kernel has the CONFIG_PNFS_BLOCK -option enabled, the blkmapd daemon from nfs-utils is running, and the -file system is mounted using the NFSv4.1 protocol version (mount -o vers=4.1). - -If the nfsd server needs to fence a non-responding client it calls -/sbin/nfsd-recall-failed with the first argument set to the IP address of -the client, and the second argument set to the device node without the /dev -prefix for the file system to be fenced. Below is an example file that shows -how to translate the device into a serial number from SCSI EVPD 0x80: - -cat > /sbin/nfsd-recall-failed << EOF -#!/bin/sh - -CLIENT="$1" -DEV="/dev/$2" -EVPD=`sg_inq --page=0x80 ${DEV} | \ - grep "Unit serial number:" | \ - awk -F ': ' '{print $2}'` - -echo "fencing client ${CLIENT} serial ${EVPD}" >> /var/log/pnfsd-fence.log -EOF -- cgit v1.2.3-59-g8ed1b From 98600b71f2bfc066d5dc8a25abf5fef84f8fc96c Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:30 -0300 Subject: Documentation: nfs: pnfs-scsi-server: convert to ReST Convert pnfs-scsi-server to ReST and move it to admin-guide. Content remains mostly unchanged. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/5c4b8af41ca0a427a3987535815bccf47a65d320.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/index.rst | 1 + Documentation/admin-guide/nfs/pnfs-scsi-server.rst | 24 ++++++++++++++++++++++ Documentation/filesystems/nfs/pnfs-scsi-server.txt | 23 --------------------- 3 files changed, 25 insertions(+), 23 deletions(-) create mode 100644 Documentation/admin-guide/nfs/pnfs-scsi-server.rst delete mode 100644 Documentation/filesystems/nfs/pnfs-scsi-server.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index 365f42a611a4..3601a708f333 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -11,3 +11,4 @@ NFS nfsd-admin-interfaces nfs-idmapper pnfs-block-server + pnfs-scsi-server diff --git a/Documentation/admin-guide/nfs/pnfs-scsi-server.rst b/Documentation/admin-guide/nfs/pnfs-scsi-server.rst new file mode 100644 index 000000000000..d2f6ee558071 --- /dev/null +++ b/Documentation/admin-guide/nfs/pnfs-scsi-server.rst @@ -0,0 +1,24 @@ + +================================== +pNFS SCSI layout server user guide +================================== + +This document describes support for pNFS SCSI layouts in the Linux NFS server. +With pNFS SCSI layouts, the NFS server acts as Metadata Server (MDS) for pNFS, +which in addition to handling all the metadata access to the NFS export, +also hands out layouts to the clients so that they can directly access the +underlying SCSI LUNs that are shared with the client. + +To use pNFS SCSI layouts with with the Linux NFS server, the exported file +system needs to support the pNFS SCSI layouts (currently just XFS), and the +file system must sit on a SCSI LUN that is accessible to the clients in +addition to the MDS. As of now the file system needs to sit directly on the +exported LUN, striping or concatenation of LUNs on the MDS and clients +is not supported yet. + +On a server built with CONFIG_NFSD_SCSI, the pNFS SCSI volume support is +automatically enabled if the file system is exported using the "pnfs" +option and the underlying SCSI device support persistent reservations. +On the client make sure the kernel has the CONFIG_PNFS_BLOCK option +enabled, and the file system is mounted using the NFSv4.1 protocol +version (mount -o vers=4.1). diff --git a/Documentation/filesystems/nfs/pnfs-scsi-server.txt b/Documentation/filesystems/nfs/pnfs-scsi-server.txt deleted file mode 100644 index 5bef7268bd9f..000000000000 --- a/Documentation/filesystems/nfs/pnfs-scsi-server.txt +++ /dev/null @@ -1,23 +0,0 @@ - -pNFS SCSI layout server user guide -================================== - -This document describes support for pNFS SCSI layouts in the Linux NFS server. -With pNFS SCSI layouts, the NFS server acts as Metadata Server (MDS) for pNFS, -which in addition to handling all the metadata access to the NFS export, -also hands out layouts to the clients so that they can directly access the -underlying SCSI LUNs that are shared with the client. - -To use pNFS SCSI layouts with with the Linux NFS server, the exported file -system needs to support the pNFS SCSI layouts (currently just XFS), and the -file system must sit on a SCSI LUN that is accessible to the clients in -addition to the MDS. As of now the file system needs to sit directly on the -exported LUN, striping or concatenation of LUNs on the MDS and clients -is not supported yet. - -On a server built with CONFIG_NFSD_SCSI, the pNFS SCSI volume support is -automatically enabled if the file system is exported using the "pnfs" -option and the underlying SCSI device support persistent reservations. -On the client make sure the kernel has the CONFIG_PNFS_BLOCK option -enabled, and the file system is mounted using the NFSv4.1 protocol -version (mount -o vers=4.1). -- cgit v1.2.3-59-g8ed1b From 6996e8ca8ba9727aac967577277c25b91f11705a Mon Sep 17 00:00:00 2001 From: "Daniel W. S. Almeida" Date: Fri, 10 Jan 2020 20:24:31 -0300 Subject: Documentation: nfs: fault_injection: convert to ReST Convert fault_injection.txt to ReST and move it to admin-guide. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/f7b0cf8fb1159a668f75ce82a581e7590568c2b8.1578697871.git.dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/nfs/fault_injection.rst | 70 +++++++++++++++++++++++ Documentation/admin-guide/nfs/index.rst | 1 + Documentation/filesystems/nfs/fault_injection.txt | 69 ---------------------- 3 files changed, 71 insertions(+), 69 deletions(-) create mode 100644 Documentation/admin-guide/nfs/fault_injection.rst delete mode 100644 Documentation/filesystems/nfs/fault_injection.txt (limited to 'Documentation') diff --git a/Documentation/admin-guide/nfs/fault_injection.rst b/Documentation/admin-guide/nfs/fault_injection.rst new file mode 100644 index 000000000000..eb029c0c15ce --- /dev/null +++ b/Documentation/admin-guide/nfs/fault_injection.rst @@ -0,0 +1,70 @@ +=================== +NFS Fault Injection +=================== + +Fault injection is a method for forcing errors that may not normally occur, or +may be difficult to reproduce. Forcing these errors in a controlled environment +can help the developer find and fix bugs before their code is shipped in a +production system. Injecting an error on the Linux NFS server will allow us to +observe how the client reacts and if it manages to recover its state correctly. + +NFSD_FAULT_INJECTION must be selected when configuring the kernel to use this +feature. + + +Using Fault Injection +===================== +On the client, mount the fault injection server through NFS v4.0+ and do some +work over NFS (open files, take locks, ...). + +On the server, mount the debugfs filesystem to and ls +/nfsd. This will show a list of files that will be used for +injecting faults on the NFS server. As root, write a number n to the file +corresponding to the action you want the server to take. The server will then +process the first n items it finds. So if you want to forget 5 locks, echo '5' +to /nfsd/forget_locks. A value of 0 will tell the server to forget +all corresponding items. A log message will be created containing the number +of items forgotten (check dmesg). + +Go back to work on the client and check if the client recovered from the error +correctly. + + +Available Faults +================ +forget_clients: + The NFS server keeps a list of clients that have placed a mount call. If + this list is cleared, the server will have no knowledge of who the client + is, forcing the client to reauthenticate with the server. + +forget_openowners: + The NFS server keeps a list of what files are currently opened and who + they were opened by. Clearing this list will force the client to reopen + its files. + +forget_locks: + The NFS server keeps a list of what files are currently locked in the VFS. + Clearing this list will force the client to reclaim its locks (files are + unlocked through the VFS as they are cleared from this list). + +forget_delegations: + A delegation is used to assure the client that a file, or part of a file, + has not changed since the delegation was awarded. Clearing this list will + force the client to reacquire its delegation before accessing the file + again. + +recall_delegations: + Delegations can be recalled by the server when another client attempts to + access a file. This test will notify the client that its delegation has + been revoked, forcing the client to reacquire the delegation before using + the file again. + + +tools/nfs/inject_faults.sh script +================================= +This script has been created to ease the fault injection process. This script +will detect the mounted debugfs directory and write to the files located there +based on the arguments passed by the user. For example, running +`inject_faults.sh forget_locks 1` as root will instruct the server to forget +one lock. Running `inject_faults forget_locks` will instruct the server to +forgetall locks. diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst index 3601a708f333..6b5a3c90fac5 100644 --- a/Documentation/admin-guide/nfs/index.rst +++ b/Documentation/admin-guide/nfs/index.rst @@ -12,3 +12,4 @@ NFS nfs-idmapper pnfs-block-server pnfs-scsi-server + fault_injection diff --git a/Documentation/filesystems/nfs/fault_injection.txt b/Documentation/filesystems/nfs/fault_injection.txt deleted file mode 100644 index f3a5b0a8ac05..000000000000 --- a/Documentation/filesystems/nfs/fault_injection.txt +++ /dev/null @@ -1,69 +0,0 @@ - -Fault Injection -=============== -Fault injection is a method for forcing errors that may not normally occur, or -may be difficult to reproduce. Forcing these errors in a controlled environment -can help the developer find and fix bugs before their code is shipped in a -production system. Injecting an error on the Linux NFS server will allow us to -observe how the client reacts and if it manages to recover its state correctly. - -NFSD_FAULT_INJECTION must be selected when configuring the kernel to use this -feature. - - -Using Fault Injection -===================== -On the client, mount the fault injection server through NFS v4.0+ and do some -work over NFS (open files, take locks, ...). - -On the server, mount the debugfs filesystem to and ls -/nfsd. This will show a list of files that will be used for -injecting faults on the NFS server. As root, write a number n to the file -corresponding to the action you want the server to take. The server will then -process the first n items it finds. So if you want to forget 5 locks, echo '5' -to /nfsd/forget_locks. A value of 0 will tell the server to forget -all corresponding items. A log message will be created containing the number -of items forgotten (check dmesg). - -Go back to work on the client and check if the client recovered from the error -correctly. - - -Available Faults -================ -forget_clients: - The NFS server keeps a list of clients that have placed a mount call. If - this list is cleared, the server will have no knowledge of who the client - is, forcing the client to reauthenticate with the server. - -forget_openowners: - The NFS server keeps a list of what files are currently opened and who - they were opened by. Clearing this list will force the client to reopen - its files. - -forget_locks: - The NFS server keeps a list of what files are currently locked in the VFS. - Clearing this list will force the client to reclaim its locks (files are - unlocked through the VFS as they are cleared from this list). - -forget_delegations: - A delegation is used to assure the client that a file, or part of a file, - has not changed since the delegation was awarded. Clearing this list will - force the client to reacquire its delegation before accessing the file - again. - -recall_delegations: - Delegations can be recalled by the server when another client attempts to - access a file. This test will notify the client that its delegation has - been revoked, forcing the client to reacquire the delegation before using - the file again. - - -tools/nfs/inject_faults.sh script -================================= -This script has been created to ease the fault injection process. This script -will detect the mounted debugfs directory and write to the files located there -based on the arguments passed by the user. For example, running -`inject_faults.sh forget_locks 1` as root will instruct the server to forget -one lock. Running `inject_faults forget_locks` will instruct the server to -forgetall locks. -- cgit v1.2.3-59-g8ed1b From 6535a39ffa88d24e7b277737e6a7405181f68710 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 15 Jan 2020 18:43:05 +0000 Subject: Documentation: Call out example SYM_FUNC_* usage as x86-specific The example given in asm-annotations.rst to describe the constraints that a function should meet in order to be annotated with a SYM_FUNC_* macro is x86-specific, and not necessarily applicable to architectures using branch-and-link style calling conventions such as arm64. Tweak the example text to call out the x86-specific text. Cc: Mark Brown Cc: Jiri Slaby Signed-off-by: Will Deacon Link: https://lore.kernel.org/r/20200115184305.1187-1-will@kernel.org Signed-off-by: Jonathan Corbet --- Documentation/asm-annotations.rst | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/asm-annotations.rst b/Documentation/asm-annotations.rst index f55c2bb74d00..32ea57483378 100644 --- a/Documentation/asm-annotations.rst +++ b/Documentation/asm-annotations.rst @@ -73,10 +73,11 @@ The new macros are prefixed with the ``SYM_`` prefix and can be divided into three main groups: 1. ``SYM_FUNC_*`` -- to annotate C-like functions. This means functions with - standard C calling conventions, i.e. the stack contains a return address at - the predefined place and a return from the function can happen in a - standard way. When frame pointers are enabled, save/restore of frame - pointer shall happen at the start/end of a function, respectively, too. + standard C calling conventions. For example, on x86, this means that the + stack contains a return address at the predefined place and a return from + the function can happen in a standard way. When frame pointers are enabled, + save/restore of frame pointer shall happen at the start/end of a function, + respectively, too. Checking tools like ``objtool`` should ensure such marked functions conform to these rules. The tools can also easily annotate these functions with -- cgit v1.2.3-59-g8ed1b From bcac386f3d3940354e76ab6309e4279134848424 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Wed, 22 Jan 2020 16:06:28 -0700 Subject: docs: Keep up with the location of NoUri Sphinx 2.1 moved sphinx.environment.NoUri into sphinx.errors; that produced this warning in the docs build: /usr/lib/python3.7/site-packages/sphinx/registry.py:473: RemovedInSphinx30Warning: sphinx.environment.NoUri is deprecated. Grab NoUri from the right place and make the warning go away. That symbol was only added to sphinx.errors in 2.1, so we must still import it from the old location when running in older versions. Signed-off-by: Jonathan Corbet --- Documentation/sphinx/automarkup.py | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/sphinx/automarkup.py b/Documentation/sphinx/automarkup.py index 5b6119ff69f4..b18236370742 100644 --- a/Documentation/sphinx/automarkup.py +++ b/Documentation/sphinx/automarkup.py @@ -5,8 +5,13 @@ # has been done. # from docutils import nodes +import sphinx from sphinx import addnodes -from sphinx.environment import NoUri +if sphinx.version_info[0] < 2 or \ + sphinx.version_info[0] == 2 and sphinx.version_info[1] < 1: + from sphinx.environment import NoUri +else: + from sphinx.errors import NoUri import re # -- cgit v1.2.3-59-g8ed1b From d96574b0b49d6c93f148333bd36d541281fc4636 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Wed, 22 Jan 2020 10:34:11 -0700 Subject: Add a document on how to contribute to the documentation This is mostly a collection of thoughts for how people who want to help out can make the docs better. Hopefully the world will respond with a flurry of useful patches. Acked-by: Jani Nikula Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Randy Dunlap Signed-off-by: Jonathan Corbet --- Documentation/doc-guide/contributing.rst | 294 +++++++++++++++++++++++++++++++ Documentation/doc-guide/index.rst | 1 + 2 files changed, 295 insertions(+) create mode 100644 Documentation/doc-guide/contributing.rst (limited to 'Documentation') diff --git a/Documentation/doc-guide/contributing.rst b/Documentation/doc-guide/contributing.rst new file mode 100644 index 000000000000..10956583d22e --- /dev/null +++ b/Documentation/doc-guide/contributing.rst @@ -0,0 +1,294 @@ +.. SPDX-License-Identifier: GPL-2.0 +How to help improve kernel documentation +======================================== + +Documentation is an important part of any software-development project. +Good documentation helps to bring new developers in and helps established +developers work more effectively. Without top-quality documentation, a lot +of time is wasted in reverse-engineering the code and making avoidable +mistakes. + +Unfortunately, the kernel's documentation currently falls far short of what +it needs to be to support a project of this size and importance. + +This guide is for contributors who would like to improve that situation. +Kernel documentation improvements can be made by developers at a variety of +skill levels; they are a relatively easy way to learn the kernel process in +general and find a place in the community. The bulk of what follows is the +documentation maintainer's list of tasks that most urgently need to be +done. + +The documentation TODO list +--------------------------- + +There is an endless list of tasks that need to be carried out to get our +documentation to where it should be. This list contains a number of +important items, but is far from exhaustive; if you see a different way to +improve the documentation, please do not hold back! + +Addressing warnings +~~~~~~~~~~~~~~~~~~~ + +The documentation build currently spews out an unbelievable number of +warnings. When you have that many, you might as well have none at all; +people ignore them, and they will never notice when their work adds new +ones. For this reason, eliminating warnings is one of the highest-priority +tasks on the documentation TODO list. The task itself is reasonably +straightforward, but it must be approached in the right way to be +successful. + +Warnings issued by a compiler for C code can often be dismissed as false +positives, leading to patches aimed at simply shutting the compiler up. +Warnings from the documentation build almost always point at a real +problem; making those warnings go away requires understanding the problem +and fixing it at its source. For this reason, patches fixing documentation +warnings should probably not say "fix a warning" in the changelog title; +they should indicate the real problem that has been fixed. + +Another important point is that documentation warnings are often created by +problems in kerneldoc comments in C code. While the documentation +maintainer appreciates being copied on fixes for these warnings, the +documentation tree is often not the right one to actually carry those +fixes; they should go to the maintainer of the subsystem in question. + +For example, in a documentation build I grabbed a pair of warnings nearly +at random:: + + ./drivers/devfreq/devfreq.c:1818: warning: bad line: + - Resource-managed devfreq_register_notifier() + ./drivers/devfreq/devfreq.c:1854: warning: bad line: + - Resource-managed devfreq_unregister_notifier() + +(The lines were split for readability). + +A quick look at the source file named above turned up a couple of kerneldoc +comments that look like this:: + + /** + * devm_devfreq_register_notifier() + - Resource-managed devfreq_register_notifier() + * @dev: The devfreq user device. (parent of devfreq) + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + * @list: DEVFREQ_TRANSITION_NOTIFIER. + */ + +The problem is the missing "*", which confuses the build system's +simplistic idea of what C comment blocks look like. This problem had been +present since that comment was added in 2016 — a full four years. Fixing +it was a matter of adding the missing asterisks. A quick look at the +history for that file showed what the normal format for subject lines is, +and ``scripts/get_maintainer.pl`` told me who should receive it. The +resulting patch looked like this:: + + [PATCH] PM / devfreq: Fix two malformed kerneldoc comments + + Two kerneldoc comments in devfreq.c fail to adhere to the required format, + resulting in these doc-build warnings: + + ./drivers/devfreq/devfreq.c:1818: warning: bad line: + - Resource-managed devfreq_register_notifier() + ./drivers/devfreq/devfreq.c:1854: warning: bad line: + - Resource-managed devfreq_unregister_notifier() + + Add a couple of missing asterisks and make kerneldoc a little happier. + + Signed-off-by: Jonathan Corbet + --- + drivers/devfreq/devfreq.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + + diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c + index 57f6944d65a6..00c9b80b3d33 100644 + --- a/drivers/devfreq/devfreq.c + +++ b/drivers/devfreq/devfreq.c + @@ -1814,7 +1814,7 @@ static void devm_devfreq_notifier_release(struct device *dev, void *res) + + /** + * devm_devfreq_register_notifier() + - - Resource-managed devfreq_register_notifier() + + * - Resource-managed devfreq_register_notifier() + * @dev: The devfreq user device. (parent of devfreq) + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + @@ -1850,7 +1850,7 @@ EXPORT_SYMBOL(devm_devfreq_register_notifier); + + /** + * devm_devfreq_unregister_notifier() + - - Resource-managed devfreq_unregister_notifier() + + * - Resource-managed devfreq_unregister_notifier() + * @dev: The devfreq user device. (parent of devfreq) + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + -- + 2.24.1 + +The entire process only took a few minutes. Of course, I then found that +somebody else had fixed it in a separate tree, highlighting another lesson: +always check linux-next to see if a problem has been fixed before you dig +into it. + +Other fixes will take longer, especially those relating to structure +members or function parameters that lack documentation. In such cases, it +is necessary to work out what the role of those members or parameters is +and describe them correctly. Overall, this task gets a little tedious at +times, but it's highly important. If we can actually eliminate warnings +from the documentation build, then we can start expecting developers to +avoid adding new ones. + +Languishing kerneldoc comments +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Developers are encouraged to write kerneldoc comments for their code, but +many of those comments are never pulled into the docs build. That makes +this information harder to find and, for example, makes Sphinx unable to +generate links to that documentation. Adding ``kernel-doc`` directives to +the documentation to bring those comments in can help the community derive +the full value of the work that has gone into creating them. + +The ``scripts/find-unused-docs.sh`` tool can be used to find these +overlooked comments. + +Note that the most value comes from pulling in the documentation for +exported functions and data structures. Many subsystems also have +kerneldoc comments for internal use; those should not be pulled into the +documentation build unless they are placed in a document that is +specifically aimed at developers working within the relevant subsystem. + + +Typo fixes +~~~~~~~~~~ + +Fixing typographical or formatting errors in the documentation is a quick +way to figure out how to create and send patches, and it is a useful +service. I am always willing to accept such patches. That said, once you +have fixed a few, please consider moving on to more advanced tasks, leaving +some typos for the next beginner to address. + +Please note that some things are *not* typos and should not be "fixed": + + - Both American and British English spellings are allowed within the + kernel documentation. There is no need to fix one by replacing it with + the other. + + - The question of whether a period should be followed by one or two spaces + is not to be debated in the context of kernel documentation. Other + areas of rational disagreement, such as the "Oxford comma", are also + off-topic here. + +As with any patch to any project, please consider whether your change is +really making things better. + +Ancient documentation +~~~~~~~~~~~~~~~~~~~~~ + +Some kernel documentation is current, maintained, and useful. Some +documentation is ... not. Dusty, old, and inaccurate documentation can +mislead readers and casts doubt on our documentation as a whole. Anything +that can be done to address such problems is more than welcome. + +Whenever you are working with a document, please consider whether it is +current, whether it needs updating, or whether it should perhaps be removed +altogether. There are a number of warning signs that you can pay attention +to here: + + - References to 2.x kernels + - Pointers to SourceForge repositories + - Nothing but typo fixes in the history for several years + - Discussion of pre-Git workflows + +The best thing to do, of course, would be to bring the documentation +current, adding whatever information is needed. Such work often requires +the cooperation of developers familiar with the subsystem in question, of +course. Developers are often more than willing to cooperate with people +working to improve the documentation when asked nicely, and when their +answers are listened to and acted upon. + +Some documentation is beyond hope; we occasionally find documents that +refer to code that was removed from the kernel long ago, for example. +There is surprising resistance to removing obsolete documentation, but we +should do that anyway. Extra cruft in our documentation helps nobody. + +In cases where there is perhaps some useful information in a badly outdated +document, and you are unable to update it, the best thing to do may be to +add a warning at the beginning. The following text is recommended:: + + .. warning :: + This document is outdated and in need of attention. Please use + this information with caution, and please consider sending patches + to update it. + +That way, at least our long-suffering readers have been warned that the +document may lead them astray. + +Documentation coherency +~~~~~~~~~~~~~~~~~~~~~~~ + +The old-timers around here will remember the Linux books that showed up on +the shelves in the 1990s. They were simply collections of documentation +files scrounged from various locations on the net. The books have (mostly) +improved since then, but the kernel's documentation is still mostly built +on that model. It is thousands of files, almost each of which was written +in isolation from all of the others. We don't have a coherent body of +kernel documentation; we have thousands of individual documents. + +We have been trying to improve the situation through the creation of +a set of "books" that group documentation for specific readers. These +include: + + - :doc:`../admin-guide/index` + - :doc:`../core-api/index` + - :doc:`../driver-api/index` + - :doc:`../userspace-api/index` + +As well as this book on documentation itself. + +Moving documents into the appropriate books is an important task and needs +to continue. There are a couple of challenges associated with this work, +though. Moving documentation files creates short-term pain for the people +who work with those files; they are understandably unenthusiastic about +such changes. Usually the case can be made to move a document once; we +really don't want to keep shifting them around, though. + +Even when all documents are in the right place, though, we have only +managed to turn a big pile into a group of smaller piles. The work of +trying to knit all of those documents together into a single whole has not +yet begun. If you have bright ideas on how we could proceed on that front, +we would be more than happy to hear them. + +Stylesheet improvements +~~~~~~~~~~~~~~~~~~~~~~~ + +With the adoption of Sphinx we have much nicer-looking HTML output than we +once did. But it could still use a lot of improvement; Donald Knuth and +Edward Tufte would be unimpressed. That requires tweaking our stylesheets +to create more typographically sound, accessible, and readable output. + +Be warned: if you take on this task you are heading into classic bikeshed +territory. Expect a lot of opinions and discussion for even relatively +obvious changes. That is, alas, the nature of the world we live in. + +Non-LaTeX PDF build +~~~~~~~~~~~~~~~~~~~ + +This is a decidedly nontrivial task for somebody with a lot of time and +Python skills. The Sphinx toolchain is relatively small and well +contained; it is easy to add to a development system. But building PDF or +EPUB output requires installing LaTeX, which is anything but small or well +contained. That would be a nice thing to eliminate. + +The original hope had been to use the rst2pdf tool (https://rst2pdf.org/) +for PDF generation, but it turned out to not be up to the task. +Development work on rst2pdf seems to have picked up again in recent times, +though, which is a hopeful sign. If a suitably motivated developer were to +work with that project to make rst2pdf work with the kernel documentation +build, the world would be eternally grateful. + +Write more documentation +~~~~~~~~~~~~~~~~~~~~~~~~ + +Naturally, there are massive parts of the kernel that are severely +underdocumented. If you have the knowledge to document a specific kernel +subsystem and the desire to do so, please do not hesitate to do some +writing and contribute the result to the kernel. Untold numbers of kernel +developers and users will thank you. diff --git a/Documentation/doc-guide/index.rst b/Documentation/doc-guide/index.rst index 603f3ff55d5a..c58de84c0d5b 100644 --- a/Documentation/doc-guide/index.rst +++ b/Documentation/doc-guide/index.rst @@ -10,6 +10,7 @@ How to write kernel documentation sphinx kernel-doc parse-headers + contributing .. only:: subproject and html -- cgit v1.2.3-59-g8ed1b From 53b7f3aa411bb812c7a4f8af1ab9e0d2288b56cf Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Wed, 22 Jan 2020 16:05:43 -0700 Subject: Add a maintainer entry profile for documentation Documentation should lead by example, so here's a basic maintainer entry profile for this subsystem. Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Jonathan Corbet --- Documentation/doc-guide/index.rst | 1 + Documentation/doc-guide/maintainer-profile.rst | 44 ++++++++++++++++++++++ .../maintainer/maintainer-entry-profile.rst | 1 + 3 files changed, 46 insertions(+) create mode 100644 Documentation/doc-guide/maintainer-profile.rst (limited to 'Documentation') diff --git a/Documentation/doc-guide/index.rst b/Documentation/doc-guide/index.rst index c58de84c0d5b..7c7d97784626 100644 --- a/Documentation/doc-guide/index.rst +++ b/Documentation/doc-guide/index.rst @@ -11,6 +11,7 @@ How to write kernel documentation kernel-doc parse-headers contributing + maintainer-profile .. only:: subproject and html diff --git a/Documentation/doc-guide/maintainer-profile.rst b/Documentation/doc-guide/maintainer-profile.rst new file mode 100644 index 000000000000..aee2f508cc89 --- /dev/null +++ b/Documentation/doc-guide/maintainer-profile.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0 +Documentation subsystem maintainer entry profile +================================================ + +The documentation "subsystem" is the central coordinating point for the +kernel's documentation and associated infrastructure. It covers the +hierarchy under Documentation/ (with the exception of +Documentation/device-tree), various utilities under scripts/ and, at least +some of the time, LICENSES/. + +It's worth noting, though, that the boundaries of this subsystem are rather +fuzzier than normal. Many other subsystem maintainers like to keep control +of portions of Documentation/, and many more freely apply changes there +when it is convenient. Beyond that, much of the kernel's documentation is +found in the source as kerneldoc comments; those are usually (but not +always) maintained by the relevant subsystem maintainer. + +The mailing list for documentation is linux-doc@vger.kernel.org. Patches +should be made against the docs-next tree whenever possible. + +Submit checklist addendum +------------------------- + +When making documentation changes, you should actually build the +documentation and ensure that no new errors or warnings have been +introduced. Generating HTML documents and looking at the result will help +to avoid unsightly misunderstandings about how things will be rendered. + +Key cycle dates +--------------- + +Patches can be sent anytime, but response will be slower than usual during +the merge window. The docs tree tends to close late before the merge +window opens, since the risk of regressions from documentation patches is +low. + +Review cadence +-------------- + +I am the sole maintainer for the documentation subsystem, and I am doing +the work on my own time, so the response to patches will occasionally be +slow. I try to always send out a notification when a patch is merged (or +when I decide that one cannot be). Do not hesitate to send a ping if you +have not heard back within a week of sending a patch. diff --git a/Documentation/maintainer/maintainer-entry-profile.rst b/Documentation/maintainer/maintainer-entry-profile.rst index 3eaddc8ac56d..11ebe3682771 100644 --- a/Documentation/maintainer/maintainer-entry-profile.rst +++ b/Documentation/maintainer/maintainer-entry-profile.rst @@ -99,4 +99,5 @@ to do something different in the near future. .. toctree:: :maxdepth: 1 + ../doc-guide/maintainer-profile ../nvdimm/maintainer-entry-profile -- cgit v1.2.3-59-g8ed1b From a3e1c56a0b8f3b83807d67db4c3bdb6292a54dce Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 20 Jan 2020 14:51:41 -0800 Subject: Documentation: zram: various fixes in zram.rst Fix various items in zram.rst: - typos/spellos - punctuation - grammar - shell syntax - indentation - sysfs file names Signed-off-by: Randy Dunlap Acked-by: Minchan Kim Link: https://lore.kernel.org/r/77000e12-677a-62f6-9f78-343be5bd6630@infradead.org Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/blockdev/zram.rst | 61 +++++++++++++++-------------- 1 file changed, 31 insertions(+), 30 deletions(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 6eccf13219ff..89d49a0d45fc 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -1,15 +1,15 @@ ======================================== -zram: Compressed RAM based block devices +zram: Compressed RAM-based block devices ======================================== Introduction ============ -The zram module creates RAM based block devices named /dev/zram +The zram module creates RAM-based block devices named /dev/zram ( = 0, 1, ...). Pages written to these disks are compressed and stored in memory itself. These disks allow very fast I/O and compression provides -good amounts of memory savings. Some of the usecases include /tmp storage, -use as swap disks, various caches under /var and maybe many more :) +good amounts of memory savings. Some of the use cases include /tmp storage, +use as swap disks, various caches under /var and maybe many more. :) Statistics for individual zram devices are exported through sysfs nodes at /sys/block/zram/ @@ -43,17 +43,17 @@ The list of possible return codes: ======== ============================================================= -EBUSY an attempt to modify an attribute that cannot be changed once - the device has been initialised. Please reset device first; + the device has been initialised. Please reset device first. -ENOMEM zram was not able to allocate enough memory to fulfil your - needs; + needs. -EINVAL invalid input has been provided. ======== ============================================================= -If you use 'echo', the returned value that is changed by 'echo' utility, +If you use 'echo', the returned value is set by the 'echo' utility, and, in general case, something like:: echo 3 > /sys/block/zram0/max_comp_streams - if [ $? -ne 0 ]; + if [ $? -ne 0 ]; then handle_error fi @@ -65,7 +65,8 @@ should suffice. :: modprobe zram num_devices=4 - This creates 4 devices: /dev/zram{0,1,2,3} + +This creates 4 devices: /dev/zram{0,1,2,3} num_devices parameter is optional and tells zram how many devices should be pre-created. Default: 1. @@ -73,12 +74,12 @@ pre-created. Default: 1. 2) Set max number of compression streams ======================================== -Regardless the value passed to this attribute, ZRAM will always -allocate multiple compression streams - one per online CPUs - thus +Regardless of the value passed to this attribute, ZRAM will always +allocate multiple compression streams - one per online CPU - thus allowing several concurrent compression operations. The number of allocated compression streams goes down when some of the CPUs become offline. There is no single-compression-stream mode anymore, -unless you are running a UP system or has only 1 CPU online. +unless you are running a UP system or have only 1 CPU online. To find out how many streams are currently available:: @@ -89,7 +90,7 @@ To find out how many streams are currently available:: Using comp_algorithm device attribute one can see available and currently selected (shown in square brackets) compression algorithms, -change selected compression algorithm (once the device is initialised +or change the selected compression algorithm (once the device is initialised there is no way to change compression algorithm). Examples:: @@ -167,9 +168,9 @@ Examples:: zram provides a control interface, which enables dynamic (on-demand) device addition and removal. -In order to add a new /dev/zramX device, perform read operation on hot_add -attribute. This will return either new device's device id (meaning that you -can use /dev/zram) or error code. +In order to add a new /dev/zramX device, perform a read operation on the hot_add +attribute. This will return either the new device's device id (meaning that you +can use /dev/zram) or an error code. Example:: @@ -186,8 +187,8 @@ execute:: Per-device statistics are exported as various nodes under /sys/block/zram/ -A brief description of exported device attributes. For more details please -read Documentation/ABI/testing/sysfs-block-zram. +A brief description of exported device attributes follows. For more details +please read Documentation/ABI/testing/sysfs-block-zram. ====================== ====== =============================================== Name access description @@ -245,7 +246,7 @@ whitespace: File /sys/block/zram/mm_stat -The stat file represents device's mm statistics. It consists of a single +The mm_stat file represents the device's mm statistics. It consists of a single line of text and contains the following stats separated by whitespace: ================ ============================================================= @@ -261,7 +262,7 @@ line of text and contains the following stats separated by whitespace: Unit: bytes mem_limit the maximum amount of memory ZRAM can use to store the compressed data - mem_used_max the maximum amount of memory zram have consumed to + mem_used_max the maximum amount of memory zram has consumed to store the data same_pages the number of same element filled pages written to this disk. No memory is allocated for such pages. @@ -271,7 +272,7 @@ line of text and contains the following stats separated by whitespace: File /sys/block/zram/bd_stat -The stat file represents device's backing device statistics. It consists of +The bd_stat file represents a device's backing device statistics. It consists of a single line of text and contains the following stats separated by whitespace: ============== ============================================================= @@ -316,7 +317,7 @@ To use the feature, admin should set up backing device via:: echo /dev/sda5 > /sys/block/zramX/backing_dev before disksize setting. It supports only partition at this moment. -If admin want to use incompressible page writeback, they could do via:: +If admin wants to use incompressible page writeback, they could do via:: echo huge > /sys/block/zramX/write @@ -326,7 +327,7 @@ as idle:: echo all > /sys/block/zramX/idle From now on, any pages on zram are idle pages. The idle mark -will be removed until someone request access of the block. +will be removed until someone requests access of the block. IOW, unless there is access request, those pages are still idle pages. Admin can request writeback of those idle pages at right timing via:: @@ -341,16 +342,16 @@ to guarantee storage health for entire product life. To overcome the concern, zram supports "writeback_limit" feature. The "writeback_limit_enable"'s default value is 0 so that it doesn't limit -any writeback. IOW, if admin want to apply writeback budget, he should +any writeback. IOW, if admin wants to apply writeback budget, he should enable writeback_limit_enable via:: $ echo 1 > /sys/block/zramX/writeback_limit_enable Once writeback_limit_enable is set, zram doesn't allow any writeback -until admin set the budget via /sys/block/zramX/writeback_limit. +until admin sets the budget via /sys/block/zramX/writeback_limit. (If admin doesn't enable writeback_limit_enable, writeback_limit's value -assigned via /sys/block/zramX/writeback_limit is meaninless.) +assigned via /sys/block/zramX/writeback_limit is meaningless.) If admin want to limit writeback as per-day 400M, he could do it like below:: @@ -361,13 +362,13 @@ like below:: /sys/block/zram0/writeback_limit. $ echo 1 > /sys/block/zram0/writeback_limit_enable -If admin want to allow further write again once the bugdet is exausted, +If admins want to allow further write again once the bugdet is exhausted, he could do it like below:: $ echo $((400<>4K_SHIFT)) > \ /sys/block/zram0/writeback_limit -If admin want to see remaining writeback budget since he set:: +If admin wants to see remaining writeback budget since last set:: $ cat /sys/block/zramX/writeback_limit @@ -375,12 +376,12 @@ If admin want to disable writeback limit, he could do:: $ echo 0 > /sys/block/zramX/writeback_limit_enable -The writeback_limit count will reset whenever you reset zram(e.g., +The writeback_limit count will reset whenever you reset zram (e.g., system reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of writeback happened until you reset the zram to allocate extra writeback budget in next setting is user's job. -If admin want to measure writeback count in a certain period, he could +If admin wants to measure writeback count in a certain period, he could know it via /sys/block/zram0/bd_stat's 3rd column. memory tracking -- cgit v1.2.3-59-g8ed1b From 5871023c3a316e8fe8c03e7bad1d35057e69ab40 Mon Sep 17 00:00:00 2001 From: Yue Hu Date: Mon, 20 Jan 2020 18:29:49 +0800 Subject: zram: correct documentation about sysfs node of huge page writeback sysfs node for huge page writeback is writeback rather than write. Signed-off-by: Yue Hu Acked-by: Minchan Kim Link: https://lore.kernel.org/r/20200120102949.12132-1-zbestahu@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/blockdev/zram.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 89d49a0d45fc..27c77d853028 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -319,7 +319,7 @@ To use the feature, admin should set up backing device via:: before disksize setting. It supports only partition at this moment. If admin wants to use incompressible page writeback, they could do via:: - echo huge > /sys/block/zramX/write + echo huge > /sys/block/zramX/writeback To use idle page writeback, first, user need to declare zram pages as idle:: -- cgit v1.2.3-59-g8ed1b From 06b9c269938ba1e9356b74584cd1ff738c0cf4de Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Sat, 18 Jan 2020 16:36:20 +0100 Subject: docs: nvdimm: use ReST notation for subsection The ACPI Device Specific Methods (_DSM) paragraph is intended to be a subsection of the Submit Checklist Addendum section. Dan Williams however used Markdown notation for this subsection, which does not parse as intended in a ReST documentation. Change the markup to ReST notation, as described in the Specific guidelines for the kernel documentation section in Documentation/doc-guide/sphinx.rst. Fixes: 47843401e3a0 ("libnvdimm, MAINTAINERS: Maintainer Entry Profile") Signed-off-by: Lukas Bulwahn Link: https://lore.kernel.org/r/20200118153620.8276-1-lukas.bulwahn@gmail.com Signed-off-by: Jonathan Corbet --- Documentation/nvdimm/maintainer-entry-profile.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/nvdimm/maintainer-entry-profile.rst b/Documentation/nvdimm/maintainer-entry-profile.rst index 77081fd9be95..efe37adadcea 100644 --- a/Documentation/nvdimm/maintainer-entry-profile.rst +++ b/Documentation/nvdimm/maintainer-entry-profile.rst @@ -33,7 +33,8 @@ Those tests need to be passed before the patches go upstream, but not necessarily before initial posting. Contact the list if you need help getting the test environment set up. -### ACPI Device Specific Methods (_DSM) +ACPI Device Specific Methods (_DSM) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Before patches enabling for a new _DSM family will be considered it must be assigned a format-interface-code from the NVDIMM Sub-team of the ACPI Specification Working Group. In general, the stance of the subsystem is -- cgit v1.2.3-59-g8ed1b From 1edca3c64e44df1665b0287fd536e79d74d884b6 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 28 Jan 2020 07:41:00 +0100 Subject: docs: usb: remove some broken references It seems that some files were removed from USB documentation. Update the links accordingly. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/00008303fde6b4e06d027d3b76ae7032614a7030.1580193653.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet --- Documentation/usb/index.rst | 2 -- Documentation/usb/text_files.rst | 6 ------ 2 files changed, 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/usb/index.rst b/Documentation/usb/index.rst index e55386a4abfb..36b6ebd9a9d9 100644 --- a/Documentation/usb/index.rst +++ b/Documentation/usb/index.rst @@ -22,11 +22,9 @@ USB support misc_usbsevseg mtouchusb ohci - rio usbip_protocol usbmon usb-serial - wusb-design-overview usb-help text_files diff --git a/Documentation/usb/text_files.rst b/Documentation/usb/text_files.rst index 6a8d3fcf64b6..1c18c05c3920 100644 --- a/Documentation/usb/text_files.rst +++ b/Documentation/usb/text_files.rst @@ -16,12 +16,6 @@ USB devfs drop permissions source .. literalinclude:: usbdevfs-drop-permissions.c :language: c -WUSB command line script to manipulate auth credentials -------------------------------------------------------- - -.. literalinclude:: wusb-cbaf - :language: shell - Credits ------- -- cgit v1.2.3-59-g8ed1b From 77ce1a47ebca88bf1eb3018855fc1709c7a1ed86 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 28 Jan 2020 07:41:01 +0100 Subject: docs: filesystems: add overlayfs to index.rst While the document is there, it is currently missing at the index file. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/3b8e7783b1fcc71e4f94af5ea8e5fa264392f8c4.1580193653.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet --- Documentation/filesystems/index.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index b03578063801..824a3ecbb0ca 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -47,5 +47,6 @@ Documentation for filesystem implementations. :maxdepth: 2 autofs + overlayfs virtiofs vfat -- cgit v1.2.3-59-g8ed1b