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2021-05-07treewide: remove editor modelines and cruftMasahiro Yamada1-3/+1
The section "19) Editor modelines and other cruft" in Documentation/process/coding-style.rst clearly says, "Do not include any of these in source files." I recently receive a patch to explicitly add a new one. Let's do treewide cleanups, otherwise some people follow the existing code and attempt to upstream their favoriate editor setups. It is even nicer if scripts/checkpatch.pl can check it. If we like to impose coding style in an editor-independent manner, I think editorconfig (patch [1]) is a saner solution. [1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/ Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-24fs: make helpers idmap mount awareChristian Brauner1-1/+2
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24namei: make permission helpers idmapped mount awareChristian Brauner1-1/+2
The two helpers inode_permission() and generic_permission() are used by the vfs to perform basic permission checking by verifying that the caller is privileged over an inode. In order to handle idmapped mounts we extend the two helpers with an additional user namespace argument. On idmapped mounts the two helpers will make sure to map the inode according to the mount's user namespace and then peform identical permission checks to inode_permission() and generic_permission(). If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2019-11-06configfs: calculate the depth of parent itemHonggang Li1-1/+1
When create symbolic link, create_link should calculate the depth of the parent item. However, both the first and second parameters of configfs_get_target_path had been set to the target. Broken symbolic link created. $ targetcli ls / o- / ............................................................. [...] o- backstores .................................................. [...] | o- block ...................................... [Storage Objects: 0] | o- fileio ..................................... [Storage Objects: 2] | | o- vdev0 .......... [/dev/ramdisk1 (16.0MiB) write-thru activated] | | | o- alua ....................................... [ALUA Groups: 1] | | | o- default_tg_pt_gp ........... [ALUA state: Active/optimized] | | o- vdev1 .......... [/dev/ramdisk2 (16.0MiB) write-thru activated] | | o- alua ....................................... [ALUA Groups: 1] | | o- default_tg_pt_gp ........... [ALUA state: Active/optimized] | o- pscsi ...................................... [Storage Objects: 0] | o- ramdisk .................................... [Storage Objects: 0] o- iscsi ................................................ [Targets: 0] o- loopback ............................................. [Targets: 0] o- srpt ................................................. [Targets: 2] | o- ib.e89a8f91cb3200000000000000000000 ............... [no-gen-acls] | | o- acls ................................................ [ACLs: 2] | | | o- ib.e89a8f91cb3200000000000000000000 ........ [Mapped LUNs: 2] | | | | o- mapped_lun0 ............................. [BROKEN LUN LINK] | | | | o- mapped_lun1 ............................. [BROKEN LUN LINK] | | | o- ib.e89a8f91cb3300000000000000000000 ........ [Mapped LUNs: 2] | | | o- mapped_lun0 ............................. [BROKEN LUN LINK] | | | o- mapped_lun1 ............................. [BROKEN LUN LINK] | | o- luns ................................................ [LUNs: 2] | | o- lun0 ...... [fileio/vdev0 (/dev/ramdisk1) (default_tg_pt_gp)] | | o- lun1 ...... [fileio/vdev1 (/dev/ramdisk2) (default_tg_pt_gp)] | o- ib.e89a8f91cb3300000000000000000000 ............... [no-gen-acls] | o- acls ................................................ [ACLs: 0] | o- luns ................................................ [LUNs: 0] o- vhost ................................................ [Targets: 0] Fixes: e9c03af21cc7 ("configfs: calculate the symlink target only once") Signed-off-by: Honggang Li <honli@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-11configfs: calculate the symlink target only onceAl Viro1-110/+54
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-11configfs: fix a deadlock in configfs_symlink()Al Viro1-1/+32
Configfs abuses symlink(2). Unlike the normal filesystems, it wants the target resolved at symlink(2) time, like link(2) would've done. The problem is that ->symlink() is called with the parent directory locked exclusive, so resolving the target inside the ->symlink() is easily deadlocked. Short of really ugly games in sys_symlink() itself, all we can do is to unlock the parent before resolving the target and relock it after. However, that invalidates the checks done by the caller of ->symlink(), so we have to * check that dentry is still where it used to be (it couldn't have been moved, but it could've been unhashed) * recheck that it's still negative (somebody else might've successfully created a symlink with the same name while we were looking the target up) * recheck the permissions on the parent directory. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145Thomas Gleixner1-15/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 021110 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 84 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-02configfs: replace strncpy with memcpyGuenter Roeck1-1/+1
gcc 8.1.0 complains: fs/configfs/symlink.c:67:3: warning: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length fs/configfs/symlink.c: In function 'configfs_get_link': fs/configfs/symlink.c:63:13: note: length computed here Using strncpy() is indeed less than perfect since the length of data to be copied has already been determined with strlen(). Replace strncpy() with memcpy() to address the warning and optimize the code a little. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19configfs: make ci_type field, some pointers and function arguments constBhumika Goyal1-2/+2
The ci_type field of the config_item structure do not modify the fields of the config_item_type structure it points to. And the other pointers initialized with ci_type do not modify the fields as well. So, make the ci_type field and the pointers initialized with ci_type as const. Make the struct config_item_type *type function argument of functions config_{item/group}_init_type_name const as the argument in both the functions is only stored in the ci_type field of a config_item structure which is now made const. Make the argument of configfs_register_default_group const as it is only passed to the argument of the function config_group_init_type_name which is now const. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-12configfs: Fix race between create_link and configfs_rmdirNicholas Bellinger1-2/+1
This patch closes a long standing race in configfs between the creation of a new symlink in create_link(), while the symlink target's config_item is being concurrently removed via configfs_rmdir(). This can happen because the symlink target's reference is obtained by config_item_get() in create_link() before the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep() during configfs_rmdir() shutdown is actually checked.. This originally manifested itself on ppc64 on v4.8.y under heavy load using ibmvscsi target ports with Novalink API: [ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added [ 7879.893760] ------------[ cut here ]------------ [ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs] [ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G O 4.8.17-customv2.22 #12 [ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000 [ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870 [ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700 Tainted: G O (4.8.17-customv2.22) [ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28222242 XER: 00000000 [ 7879.893820] CFAR: d000000002c664bc SOFTE: 1 GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820 GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000 GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80 GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40 GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940 GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000 GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490 GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940 [ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs] [ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893842] Call Trace: [ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460 [ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490 [ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170 [ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390 [ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec [ 7879.893856] Instruction dump: [ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000 [ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000 [ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]--- To close this race, go ahead and obtain the symlink's target config_item reference only after the existing CONFIGFS_USET_DROPPING check succeeds. This way, if configfs_rmdir() wins create_link() will return -ENONET, and if create_link() wins configfs_rmdir() will return -EBUSY. Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org
2016-12-09vfs: remove ".readlink = generic_readlink" assignmentsMiklos Szeredi1-1/+0
If .readlink == NULL implies generic_readlink(). Generated by: to_del="\.readlink.*=.*generic_readlink" for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2015-12-30switch ->get_link() to delayed_call, kill ->put_link()Al Viro1-8/+9
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-29kill free_page_put_link()Al Viro1-6/+6
all callers are better off with kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08replace ->follow_link() with new method that could stay in RCU modeAl Viro1-3/+8
new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new helper: free_page_put_link()Al Viro1-6/+1
similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11switch ->put_link() from dentry to inodeAl Viro1-1/+1
only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10don't pass nameidata to ->follow_link()Al Viro1-1/+1
its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10new ->follow_link() and ->put_link() calling conventionsAl Viro1-16/+12
a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20configfs: kill configfs_sbAl Viro1-3/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20configfs: don't bother with checks for mkdir/rmdir/unlink/symlink in rootAl Viro1-6/+0
just give root directory separate inode_operations without all those methods... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.hTejun Heo1-0/+1
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-01-14Fix configfs leakAl Viro1-1/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-21configfs: Fix Trivial Warning in fs/configfs/symlink.cSubrata Modak1-1/+1
I observed the following build warning with fs/configfs/symlink.c: fs/configfs/symlink.c: In function 'configfs_symlink': fs/configfs/symlink.c:138: warning: 'target_item' may be used uninitialized in this function Here is a small fix for this. Cc: Patrick Mochel <mochel@osdl.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Sachin P Sant <sachinp@linux.vnet.ibm.com> Signed-Off-By: Subrata Modak <subrata@linux.vnet.ibm.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2008-10-23[PATCH] assorted path_lookup() -> kern_path() conversionsAl Viro1-8/+8
more nameidata eviction Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-31[PATCH] configfs: Prevent userspace from creating new entries under attaching directoriesLouis Rilling1-0/+15
process 1: process 2: configfs_mkdir("A") attach_group("A") attach_item("A") d_instantiate("A") populate_groups("A") mutex_lock("A") attach_group("A/B") attach_item("A") d_instantiate("A/B") mkdir("A/B/C") do_path_lookup("A/B/C", LOOKUP_PARENT) ok lookup_create("A/B/C") mutex_lock("A/B") ok configfs_mkdir("A/B/C") ok attach_group("A/C") attach_item("A/C") d_instantiate("A/C") populate_groups("A/C") mutex_lock("A/C") attach_group("A/C/D") attach_item("A/C/D") failure mutex_unlock("A/C") detach_groups("A/C") nothing to do mkdir("A/C/E") do_path_lookup("A/C/E", LOOKUP_PARENT) ok lookup_create("A/C/E") mutex_lock("A/C") ok configfs_mkdir("A/C/E") ok detach_item("A/C") d_delete("A/C") mutex_unlock("A") detach_groups("A") mutex_lock("A/B") detach_group("A/B") detach_groups("A/B") nothing since no _default_ group detach_item("A/B") mutex_unlock("A/B") d_delete("A/B") detach_item("A") d_delete("A") Two bugs: 1/ "A/B/C" and "A/C/E" are created, but never removed while their parent are removed in the end. The same could happen with symlink() instead of mkdir(). 2/ "A" and "A/C" inodes are not locked while detach_item() is called on them, which may probably confuse VFS. This commit fixes 1/, tagging new directories with CONFIGFS_USET_CREATING before building the inode and instantiating the dentry, and validating the whole group+default groups hierarchy in a second pass by clearing CONFIGFS_USET_CREATING. mkdir(), symlink(), lookup(), and dir_open() simply return -ENOENT if called in (or linking to) a directory tagged with CONFIGFS_USET_CREATING. This does not prevent userspace from calling stat() successfuly on such directories, but this prevents userspace from adding (children to | symlinking from/to | read/write attributes of | listing the contents of) not validated items. In other words, userspace will not interact with the subsystem on a new item until the new item creation completes correctly. It was first proposed to re-use CONFIGFS_USET_IN_MKDIR instead of a new flag CONFIGFS_USET_CREATING, but this generated conflicts when checking the target of a new symlink: a valid target directory in the middle of attaching a new user-created child item could be wrongly detected as being attached. 2/ is fixed by next commit. Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-07-31[PATCH] configfs: Fix failing symlink() making rmdir() failLouis Rilling1-0/+5
On a similar pattern as mkdir() vs rmdir(), a failing symlink() may make rmdir() fail for the symlink's parent and the symlink's target as well. failing symlink() making target's rmdir() fail: process 1: process 2: symlink("A/S" -> "B") allow_link() create_link() attach to "B" links list rmdir("B") detach_prep("B") error because of new link configfs_create_link("A", "S") error (eg -ENOMEM) failing symlink() making parent's rmdir() fail: process 1: process 2: symlink("A/D/S" -> "B") allow_link() create_link() attach to "B" links list configfs_create_link("A/D", "S") make_dirent("A/D", "S") rmdir("A") detach_prep("A") detach_prep("A/D") error because of "S" create("S") error (eg -ENOMEM) We cannot use the same solution as for mkdir() vs rmdir(), since rmdir() on the target cannot wait on the i_mutex of the new symlink's parent without risking a deadlock (with other symlink() or sys_rename()). Instead we define a global mutex protecting all configfs symlinks attachment, so that rmdir() can avoid the races above. Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-07-31[PATCH] configfs: Fix symlink() to a removing itemLouis Rilling1-0/+6
The rule for configfs symlinks is that symlinks always point to valid config_items, and prevent the target from being removed. However, configfs_symlink() only checks that it can grab a reference on the target item, without ensuring that it remains alive until the symlink is correctly attached. This patch makes configfs_symlink() fail whenever the target is being removed, using the CONFIGFS_USET_DROPPING flag set by configfs_detach_prep() and protected by configfs_dirent_lock. This patch introduces a similar (weird?) behavior as with mkdir failures making rmdir fail: if symlink() races with rmdir() of the parent directory (or its youngest user-created ancestor if parent is a default group) or rmdir() of the target directory, and then fails in configfs_create(), this can make the racing rmdir() fail despite the concerned directory having no user-created entry (resp. no symlink pointing to it or one of its default groups) in the end. This behavior is fixed in later patches. Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-07-14configfs: call drop_link() to cleanup after create_link() failureLouis Rilling1-1/+5
When allow_link() succeeds but create_link() fails, the subsystem is not informed of the failure. This patch fixes this by calling drop_link() on create_link() failures. Signed-off-by: Louis Rilling <Louis.Rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2008-07-14configfs: Protect configfs_dirent s_links list mutationsLouis Rilling1-2/+6
Symlinks to a config_item are listed under its configfs_dirent s_links, but the list mutations are not protected by any common lock. This patch uses the configfs_dirent_lock spinlock to add the necessary protection. Note: we should also protect the list_empty() test in configfs_detach_prep() but 1/ the lock should not be released immediately because nothing would prevent the list from being filled after a successful list_empty() test, making the problem tricky, 2/ this will be solved by the rmdir() vs rename() deadlock bugfix. Signed-off-by: Louis Rilling <Louis.Rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2008-07-14configfs: Introduce configfs_dirent_lockLouis Rilling1-0/+2
This patch introduces configfs_dirent_lock spinlock to protect configfs_dirent traversals against linkage mutations (add/del/move). This will allow configfs_detach_prep() to avoid locking i_mutexes. Locking rules for configfs_dirent linkage mutations are the same plus the requirement of taking configfs_dirent_lock. For configfs_dirent walking, one can either take appropriate i_mutex as before, or take configfs_dirent_lock. The spinlock could actually be a mutex, but the critical sections are either O(1) or should not be too long (default groups walking in last patch). ChangeLog: - Clarify the comment on configfs_dirent_lock usage - Move sd->s_element init before linking the new dirent - In lseek(), do not release configfs_dirent_lock before the dirent is relinked. Signed-off-by: Louis Rilling <Louis.Rilling@kerlabs.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2008-04-30fs: replace remaining __FUNCTION__ occurrencesHarvey Harrison1-2/+2
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14Introduce path_put()Jan Blunck1-2/+2
* Add path_put() functions for releasing a reference to the dentry and vfsmount of a struct path in the right order * Switch from path_release(nd) to path_put(&nd->path) * Rename dput_path() to path_put_conditional() [akpm@linux-foundation.org: fix cifs] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14Embed a struct path into struct nameidata instead of nd->{dentry,mnt}Jan Blunck1-2/+2
This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on <dentry,vfsmount> pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] mark struct inode_operations const 1Arjan van de Ven1-1/+1
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-06-29configfs: Clear up a few extra spaces where there should be TABs.Joel Becker1-1/+1
Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-02-03[PATCH] BUG_ON() Conversion in fs/configfs/Eric Sesterhenn / snakebyte1-2/+1
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-02-03configfs: Add permission and ownership to configfs objects.Joel Becker1-0/+1
configfs always made item and attribute ownership root.root and permissions based on a umask of 022. Add ->setattr() to allow chown(2)/chmod(2), and persist the changes for the lifetime of the items and attributes. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-01-03[PATCH] configfs: User-driven configuration filesystemJoel Becker1-0/+281
Configfs, a file system for userspace-driven kernel object configuration. The OCFS2 stack makes extensive use of this for propagation of cluster configuration information into kernel. Signed-off-by: Joel Becker <joel.becker@oracle.com>
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