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2024-02-22dax: alloc_dax() return ERR_PTR(-EOPNOTSUPP) for CONFIG_DAX=nMathieu Desnoyers1-5/+1
Change the return value from NULL to PTR_ERR(-EOPNOTSUPP) for CONFIG_DAX=n to be consistent with the fact that CONFIG_DAX=y never returns NULL. This is done in preparation for using cpu_dcache_is_aliasing() in a following change which will properly support architectures which detect data cache aliasing at runtime. Link: https://lkml.kernel.org/r/20240215144633.96437-3-mathieu.desnoyers@efficios.com Fixes: 4e4ced93794a ("dax: Move mandatory ->zero_page_range() check in alloc_dax()") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Alasdair Kergon <agk@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: kernel test robot <lkp@intel.com> Cc: Michael Sclafani <dm-devel@lists.linux.dev> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22dax: add empty static inline for CONFIG_DAX=nMathieu Desnoyers1-3/+8
Patch series "Introduce cpu_dcache_is_aliasing() to fix DAX regression", v6. This commit introduced in v4.0 prevents building FS_DAX on 32-bit ARM, even on ARMv7 which does not have virtually aliased data caches: commit d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Even though it used to work fine before. The root of the issue here is the fact that DAX was never designed to handle virtually aliasing data caches (VIVT and VIPT with aliasing data cache). It touches the pages through their linear mapping, which is not consistent with the userspace mappings with virtually aliasing data caches. This patch series introduces cpu_dcache_is_aliasing() with the new Kconfig option ARCH_HAS_CPU_CACHE_ALIASING and implements it for all architectures. The implementation of cpu_dcache_is_aliasing() is either evaluated to a constant at compile-time or a runtime check, which is what is needed on ARM. With this we can basically narrow down the list of architectures which are unsupported by DAX to those which are really affected. This patch (of 9): When building a kernel with CONFIG_DAX=n, all uses of set_dax_nocache() and set_dax_nomc() need to be either within regions of code or compile units which are explicitly not compiled, or they need to rely on compiler optimizations to eliminate calls to those undefined symbols. It appears that at least the openrisc and loongarch architectures don't end up eliminating those undefined symbols even if they are provably within code which is eliminated due to conditional branches depending on constants. Implement empty static inline functions for set_dax_nocache() and set_dax_nomc() in CONFIG_DAX=n to ensure those undefined references are removed. Link: https://lkml.kernel.org/r/20240215144633.96437-1-mathieu.desnoyers@efficios.com Link: https://lkml.kernel.org/r/20240215144633.96437-2-mathieu.desnoyers@efficios.com Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402140037.wGfA1kqX-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402131351.a0FZOgEG-lkp@intel.com/ Fixes: 7ac5360cd4d0 ("dax: remove the copy_from_iter and copy_to_iter methods") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Cc: Michael Sclafani <dm-devel@lists.linux.dev> Cc: Alasdair Kergon <agk@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: convert DAX lock/unlock page to lock/unlock folioMatthew Wilcox (Oracle)1-5/+5
The one caller of DAX lock/unlock page already calls compound_head(), so use page_folio() instead, then use a folio throughout the DAX code to remove uses of page->mapping and page->index. [jane.chu@oracle.com: add comment to mf_generic_kill_procss(), simplify mf_generic_kill_procs:folio initialization] Link: https://lkml.kernel.org/r/20230908222336.186313-1-jane.chu@oracle.com Link: https://lkml.kernel.org/r/20230822231314.349200-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jane Chu <jane.chu@oracle.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jane Chu <jane.chu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24mm: remove enum page_entry_sizeMatthew Wilcox (Oracle)1-2/+2
Remove the unnecessary encoding of page order into an enum and pass the page order directly. That lets us get rid of pe_order(). The switch constructs have to be changed to if/else constructs to prevent GCC from warning on builds with 3-level page tables where PMD_ORDER and PUD_ORDER have the same value. If you are looking at this commit because your driver stopped compiling, look at the previous commit as well and audit your driver to be sure it doesn't depend on mmap_lock being held in its ->huge_fault method. [willy@infradead.org: use "order %u" to match the (non dev_t) style] Link: https://lkml.kernel.org/r/ZOUYekbtTv+n8hYf@casper.infradead.org Link: https://lkml.kernel.org/r/20230818202335.2739663-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-26dax: enable dax fault handler to report VM_FAULT_HWPOISONJane Chu1-0/+13
When multiple processes mmap() a dax file, then at some point, a process issues a 'load' and consumes a hwpoison, the process receives a SIGBUS with si_code = BUS_MCEERR_AR and with si_lsb set for the poison scope. Soon after, any other process issues a 'load' to the poisoned page (that is unmapped from the kernel side by memory_failure), it receives a SIGBUS with si_code = BUS_ADRERR and without valid si_lsb. This is confusing to user, and is different from page fault due to poison in RAM memory, also some helpful information is lost. Channel dax backend driver's poison detection to the filesystem such that instead of reporting VM_FAULT_SIGBUS, it could report VM_FAULT_HWPOISON. If user level block IO syscalls fail due to poison, the errno will be converted to EIO to maintain block API consistency. Signed-off-by: Jane Chu <jane.chu@oracle.com> Link: https://lore.kernel.org/r/20230615181325.1327259-2-jane.chu@oracle.com Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2023-02-10dax/hmem: Move hmem device registration to dax_hmem.koDan Williams1-2/+5
In preparation for the CXL region driver to take over the responsibility of registering device-dax instances for CXL regions, move the registration of "hmem" devices to dax_hmem.ko. Previously the builtin component of this enabling (drivers/dax/hmem/device.o) would register platform devices for each address range and trigger the dax_hmem.ko module to load and attach device-dax instances to those devices. Now, the ranges are collected from the HMAT and EFI memory map walking, but the device creation is deferred. A new "hmem_platform" device is created which triggers dax_hmem.ko to load and register the platform devices. Tested-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/167602002771.1924368.5653558226424530127.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-12-11fsdax,xfs: port unshare to fsdaxShiyang Ruan1-0/+2
Implement unshare in fsdax mode: copy data from srcmap to iomap. Link: https://lkml.kernel.org/r/1669908753-169-1-git-send-email-ruansy.fnst@fujitsu.com Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17fsdax: dedup file range to use a compare functionShiyang Ruan1-0/+8
With dax we cannot deal with readpage() etc. So, we create a dax comparison function which is similar with vfs_dedupe_file_range_compare(). And introduce dax_remap_file_range_prep() for filesystem use. Link: https://lkml.kernel.org/r/20220603053738.1218681-13-ruansy.fnst@fujitsu.com Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.wiliams@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Goldwyn Rodrigues <rgoldwyn@suse.de> Cc: Jane Chu <jane.chu@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17fsdax: introduce dax_lock_mapping_entry()Shiyang Ruan1-0/+15
The current dax_lock_page() locks dax entry by obtaining mapping and index in page. To support 1-to-N RMAP in NVDIMM, we need a new function to lock a specific dax entry corresponding to this file's mapping,index. And output the page corresponding to the specific dax entry for caller use. Link: https://lkml.kernel.org/r/20220603053738.1218681-5-ruansy.fnst@fujitsu.com Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.wiliams@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Goldwyn Rodrigues <rgoldwyn@suse.com> Cc: Goldwyn Rodrigues <rgoldwyn@suse.de> Cc: Jane Chu <jane.chu@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17dax: introduce holder for dax_deviceShiyang Ruan1-8/+25
Patch series "v14 fsdax-rmap + v11 fsdax-reflink", v2. The patchset fsdax-rmap is aimed to support shared pages tracking for fsdax. It moves owner tracking from dax_assocaite_entry() to pmem device driver, by introducing an interface ->memory_failure() for struct pagemap. This interface is called by memory_failure() in mm, and implemented by pmem device. Then call holder operations to find the filesystem which the corrupted data located in, and call filesystem handler to track files or metadata associated with this page. Finally we are able to try to fix the corrupted data in filesystem and do other necessary processing, such as killing processes who are using the files affected. The call trace is like this: memory_failure() |* fsdax case |------------ |pgmap->ops->memory_failure() => pmem_pgmap_memory_failure() | dax_holder_notify_failure() => | dax_device->holder_ops->notify_failure() => | - xfs_dax_notify_failure() | |* xfs_dax_notify_failure() | |-------------------------- | | xfs_rmap_query_range() | | xfs_dax_failure_fn() | | * corrupted on metadata | | try to recover data, call xfs_force_shutdown() | | * corrupted on file data | | try to recover data, call mf_dax_kill_procs() |* normal case |------------- |mf_generic_kill_procs() The patchset fsdax-reflink attempts to add CoW support for fsdax, and takes XFS, which has both reflink and fsdax features, as an example. One of the key mechanisms needed to be implemented in fsdax is CoW. Copy the data from srcmap before we actually write data to the destination iomap. And we just copy range in which data won't be changed. Another mechanism is range comparison. In page cache case, readpage() is used to load data on disk to page cache in order to be able to compare data. In fsdax case, readpage() does not work. So, we need another compare data with direct access support. With the two mechanisms implemented in fsdax, we are able to make reflink and fsdax work together in XFS. This patch (of 14): To easily track filesystem from a pmem device, we introduce a holder for dax_device structure, and also its operation. This holder is used to remember who is using this dax_device: - When it is the backend of a filesystem, the holder will be the instance of this filesystem. - When this pmem device is one of the targets in a mapped device, the holder will be this mapped device. In this case, the mapped device has its own dax_device and it will follow the first rule. So that we can finally track to the filesystem we needed. The holder and holder_ops will be set when filesystem is being mounted, or an target device is being activated. Link: https://lkml.kernel.org/r/20220603053738.1218681-1-ruansy.fnst@fujitsu.com Link: https://lkml.kernel.org/r/20220603053738.1218681-2-ruansy.fnst@fujitsu.com Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.wiliams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Goldwyn Rodrigues <rgoldwyn@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Goldwyn Rodrigues <rgoldwyn@suse.com> Cc: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-16dax: add .recovery_write dax_operationJane Chu1-0/+13
Introduce dax_recovery_write() operation. The function is used to recover a dax range that contains poison. Typical use case is when a user process receives a SIGBUS with si_code BUS_MCEERR_AR indicating poison(s) in a dax range, in response, the user process issues a pwrite() to the page-aligned dax range, thus clears the poison and puts valid data in the range. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jane Chu <jane.chu@oracle.com> Link: https://lore.kernel.org/r/20220422224508.440670-6-jane.chu@oracle.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-16dax: introduce DAX_RECOVERY_WRITE dax access modeJane Chu1-2/+7
Up till now, dax_direct_access() is used implicitly for normal access, but for the purpose of recovery write, dax range with poison is requested. To make the interface clear, introduce enum dax_access_mode { DAX_ACCESS, DAX_RECOVERY_WRITE, } where DAX_ACCESS is used for normal dax access, and DAX_RECOVERY_WRITE is used for dax recovery write. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jane Chu <jane.chu@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/165247982851.52965.11024212198889762949.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-18dax: remove the copy_from_iter and copy_to_iter methodsChristoph Hellwig1-6/+3
These methods indirect the actual DAX read/write path. In the end pmem uses magic flush and mc safe variants and fuse and dcssblk use plain ones while device mapper picks redirects to the underlying device. Add set_dax_nocache() and set_dax_nomc() APIs to control which copy routines are used to remove indirect call from the read/write fast path as well as a lot of boilerplate code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> [virtiofs] Link: https://lore.kernel.org/r/20211215084508.435401-5-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-18dax: remove the DAXDEV_F_SYNC flagChristoph Hellwig1-6/+2
Remove the DAXDEV_F_SYNC flag and thus the flags argument to alloc_dax and just let the drivers call set_dax_synchronous directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20211215084508.435401-4-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-18dax: simplify dax_synchronous and set_dax_synchronousChristoph Hellwig1-10/+2
Remove the pointless wrappers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20211215084508.435401-3-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04dax: fix up some of the block device related ifdefsChristoph Hellwig1-17/+16
The DAX device <-> block device association is only enabled if CONFIG_BLOCK is enabled. Update dax.h to account for that and use the right conditions for the fs_put_dax stub as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-28-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04dax: return the partition offset from fs_dax_get_by_bdevChristoph Hellwig1-2/+4
Prepare for the removal of the block_device from the DAX I/O path by returning the partition offset from fs_dax_get_by_bdev so that the file systems have it at hand for use during I/O. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-26-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04fsdax: decouple zeroing from the iomap buffered I/O codeChristoph Hellwig1-1/+6
Unshare the DAX and iomap buffered I/O page zeroing code. This code previously did a IS_DAX check deep inside the iomap code, which in fact was the only DAX check in the code. Instead move these checks into the callers. Most callers already have DAX special casing anyway and XFS will need it for reflink support as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-19-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04fsdax: simplify the pgoff calculationChristoph Hellwig1-1/+0
Replace the two steps of dax_iomap_sector and bdev_dax_pgoff with a single dax_iomap_pgoff helper that avoids lots of cumbersome sector conversions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-15-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04dax: remove dax_capableChristoph Hellwig1-14/+0
Just open code the block size and dax_dev == NULL checks in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> [erofs] Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-9-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04dax: simplify the dax_device <-> gendisk associationChristoph Hellwig1-4/+15
Replace the dax_host_hash with an xarray indexed by the pointer value of the gendisk, and require explicitly calls from the block drivers that want to associate their gendisk with a dax_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20211129102203.2243509-5-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-27nvdimm/pmem: move dax_attribute_group from dax to pmemChristoph Hellwig1-2/+0
dax_attribute_group is only used by the pmem driver, and can avoid the completely pointless lookup by the disk name if moved there. This leaves just a single caller of dax_get_by_host, so move dax_get_by_host into the same ifdef block as that caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20210922173431.2454024-3-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-26dax: remove bdev_dax_supportedChristoph Hellwig1-12/+0
All callers already have a dax_device obtained from fs_dax_get_by_bdev at hand, so just pass that to dax_supported() insted of doing another lookup. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20210826135510.6293-10-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-26dax: stub out dax_supported for !CONFIG_FS_DAXChristoph Hellwig1-8/+10
dax_supported calls into ->dax_supported which checks for fsdax support. Don't bother building it for !CONFIG_FS_DAX as it will always return false. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20210826135510.6293-8-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-26dax: remove __generic_fsdax_supportedChristoph Hellwig1-14/+2
Just implement generic_fsdax_supported directly out of line instead of adding a wrapper. Given that generic_fsdax_supported is only supplied for CONFIG_FS_DAX builds this also allows to not provide it at all for !CONFIG_FS_DAX builds. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20210826135510.6293-7-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-26dax: mark dax_get_by_host staticChristoph Hellwig1-5/+0
And move the code around a bit to avoid a forward declaration. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20210826135510.6293-5-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-10-19Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds1-0/+6
Pull fuse updates from Miklos Szeredi: - Support directly accessing host page cache from virtiofs. This can improve I/O performance for various workloads, as well as reducing the memory requirement by eliminating double caching. Thanks to Vivek Goyal for doing most of the work on this. - Allow automatic submounting inside virtiofs. This allows unique st_dev/ st_ino values to be assigned inside the guest to files residing on different filesystems on the host. Thanks to Max Reitz for the patches. - Fix an old use after free bug found by Pradeep P V K. * tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits) virtiofs: calculate number of scatter-gather elements accurately fuse: connection remove fix fuse: implement crossmounts fuse: Allow fuse_fill_super_common() for submounts fuse: split fuse_mount off of fuse_conn fuse: drop fuse_conn parameter where possible fuse: store fuse_conn in fuse_req fuse: add submount support to <uapi/linux/fuse.h> fuse: fix page dereference after free virtiofs: add logic to free up a memory range virtiofs: maintain a list of busy elements virtiofs: serialize truncate/punch_hole and dax fault path virtiofs: define dax address space operations virtiofs: add DAX mmap support virtiofs: implement dax read/write operations virtiofs: introduce setupmapping/removemapping commands virtiofs: implement FUSE_INIT map_alignment field virtiofs: keep a list of free dax memory ranges virtiofs: add a mount option to enable dax virtiofs: set up virtio_fs dax_device ...
2020-10-14Merge tag 'iomap-5.10-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds1-2/+1
Pull iomap updates from Darrick Wong: "There's not a lot of new stuff going on here -- a little bit of code refactoring to make iomap workable with btrfs' fsync locking model, cleanups in preparation for adding THP support for filesystems, and fixing a data corruption issue for blocksize < pagesize filesystems. Summary: - Don't WARN_ON weird states that unprivileged users can create. - Don't invalidate page cache when direct writes want to fall back to buffered. - Fix some problems when readahead ios fail. - Fix a problem where inline data pages weren't getting flushed during an unshare operation. - Rework iomap to support arbitrarily many blocks per page in preparation to support THP for the page cache. - Fix a bug in the blocksize < pagesize buffered io path where we could fail to initialize the many-blocks-per-page uptodate bitmap correctly when the backing page is actually up to date. This could cause us to forget to write out dirty pages. - Split out the generic_write_sync at the end of the directio write path so that btrfs can drop the inode lock before sync'ing the file. - Call inode_dio_end before trying to sync the file after a O_DSYNC direct write (instead of afterwards) to match the behavior of the old directio code" * tag 'iomap-5.10-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: Call inode_dio_end() before generic_write_sync() iomap: Allow filesystem to call iomap_dio_complete without i_rwsem iomap: Set all uptodate bits for an Uptodate page iomap: Change calling convention for zeroing iomap: Convert iomap_write_end types iomap: Convert write_count to write_bytes_pending iomap: Convert read_count to read_bytes_pending iomap: Support arbitrarily many blocks per page iomap: Use bitmap ops to set uptodate bits iomap: Use kzalloc to allocate iomap_page fs: Introduce i_blocks_per_page iomap: Fix misplaced page flushing iomap: Use round_down/round_up macros in __iomap_write_begin iomap: Mark read blocks uptodate in write_begin iomap: Clear page error before beginning a write iomap: Fix direct I/O write consistency check iomap: fix WARN_ON_ONCE() from unprivileged users
2020-10-13ACPI: HMAT: refactor hmat_register_target_device to hmem_register_deviceDan Williams1-0/+8
In preparation for exposing "Soft Reserved" memory ranges without an HMAT, move the hmem device registration to its own compilation unit and make the implementation generic. The generic implementation drops usage acpi_map_pxm_to_online_node() that was translating ACPI proximity domain values and instead relies on numa_map_to_online_node() to determine the numa node for the device. [joao.m.martins@oracle.com: CONFIG_DEV_DAX_HMEM_DEVICES should depend on CONFIG_DAX=y] Link: https://lkml.kernel.org/r/8f34727f-ec2d-9395-cb18-969ec8a5d0d4@oracle.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Link: https://lkml.kernel.org/r/159643096584.4062302.5035370788475153738.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lore.kernel.org/r/158318761484.2216124.2049322072599482736.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-21iomap: Change calling convention for zeroingMatthew Wilcox (Oracle)1-2/+1
Pass the full length to iomap_zero() and dax_iomap_zero(), and have them return how many bytes they actually handled. This is preparatory work for handling THP, although it looks like DAX could actually take advantage of it if there's a larger contiguous area. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-21dax: Fix compilation for CONFIG_DAX && !CONFIG_FS_DAXJan Kara1-9/+8
dax_supported() is defined whenever CONFIG_DAX is enabled. So dummy implementation should be defined only in !CONFIG_DAX case, not in !CONFIG_FS_DAX case. Fixes: e2ec51282545 ("dm: Call proper helper to determine dax support") Cc: <stable@vger.kernel.org> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-09-20dm: Call proper helper to determine dax supportJan Kara1-2/+20
DM was calling generic_fsdax_supported() to determine whether a device referenced in the DM table supports DAX. However this is a helper for "leaf" device drivers so that they don't have to duplicate common generic checks. High level code should call dax_supported() helper which that calls into appropriate helper for the particular device. This problem manifested itself as kernel messages: dm-3: error: dax access failed (-95) when lvm2-testsuite run in cases where a DM device was stacked on top of another DM device. Fixes: 7bf7eac8d648 ("dax: Arrange for dax_supported check to span multiple devices") Cc: <stable@vger.kernel.org> Tested-by: Adrian Huang <ahuang12@lenovo.com> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Mike Snitzer <snitzer@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/160061715195.13131.5503173247632041975.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-09-10dax: Create a range version of dax_layout_busy_page()Vivek Goyal1-0/+6
virtiofs device has a range of memory which is mapped into file inodes using dax. This memory is mapped in qemu on host and maps different sections of real file on host. Size of this memory is limited (determined by administrator) and depending on filesystem size, we will soon reach a situation where all the memory is in use and we need to reclaim some. As part of reclaim process, we will need to make sure that there are no active references to pages (taken by get_user_pages()) on the memory range we are trying to reclaim. I am planning to use dax_layout_busy_page() for this. But in current form this is per inode and scans through all the pages of the inode. We want to reclaim only a portion of memory (say 2MB page). So we want to make sure that only that 2MB range of pages do not have any references (and don't want to unmap all the pages of inode). Hence, create a range version of this function named dax_layout_busy_page_range() which can be used to pass a range which needs to be unmapped. Cc: Dan Williams <dan.j.williams@intel.com> Cc: linux-nvdimm@lists.01.org Cc: Jan Kara <jack@suse.cz> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: "Weiny, Ira" <ira.weiny@intel.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport1-1/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02dax,iomap: Add helper dax_iomap_zero() to zero a rangeVivek Goyal1-14/+3
Add a helper dax_ioamp_zero() to zero a range. This patch basically merges __dax_zero_page_range() and iomap_dax_zero(). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200228163456.1587-7-vgoyal@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-04-02dax, pmem: Add a dax operation zero_page_rangeVivek Goyal1-0/+4
Add a dax operation zero_page_range, to zero a page. This will also clear any known poison in the page being zeroed. As of now, zeroing of one page is allowed in a single call. There are no callers which are trying to zero more than a page in a single call. Once we grow the callers which zero more than a page in single call, we can add that support. Primary reason for not doing that yet is that this will add little complexity in dm implementation where a range might be spanning multiple underlying targets and one will have to split the range into multiple sub ranges and call zero_page_range() on individual targets. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-01-16dax: Get rid of fs_dax_get_by_host() helperVivek Goyal1-10/+0
Looks like nobody is using fs_dax_get_by_host() except fs_dax_get_by_bdev() and it can easily use dax_get_by_host() instead. IIUC, fs_dax_get_by_host() was only introduced so that one could compile with CONFIG_FS_DAX=n and CONFIG_DAX=m. fs_dax_get_by_bdev() achieves the same purpose and hence it looks like fs_dax_get_by_host() is not needed anymore. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200106181117.GA16248@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-01-03dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range()Vivek Goyal1-2/+2
As of now dax_writeback_mapping_range() takes "struct block_device" as a parameter and dax_dev is searched from bdev name. This also involves taking a fresh reference on dax_dev and putting that reference at the end of function. We are developing a new filesystem virtio-fs and using dax to access host page cache directly. But there is no block device. IOW, we want to make use of dax but want to get rid of this assumption that there is always a block device associated with dax_dev. So pass in "struct dax_device" as parameter instead of bdev. ext2/ext4/xfs are current users and they already have a reference on dax_device. So there is no need to take reference and drop reference to dax_device on each call of this function. Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/20200103183307.GB13350@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05dax: check synchronous mapping is supportedPankaj Gupta1-0/+17
This patch introduces 'daxdev_mapping_supported' helper which checks if 'MAP_SYNC' is supported with filesystem mapping. It also checks if corresponding dax_device is synchronous. Virtio pmem device is asynchronous and does not not support VM_SYNC. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05libnvdimm: add dax_dev sync flagPankaj Gupta1-2/+22
This patch adds 'DAXDEV_SYNC' flag which is set for nd_region doing synchronous flush. This later is used to disable MAP_SYNC functionality for ext4 & xfs filesystem for devices don't support synchronous flush. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-05-20dax: Arrange for dax_supported check to span multiple devicesDan Williams1-0/+26
Pankaj reports that starting with commit ad428cdb525a "dax: Check the end of the block-device capacity with dax_direct_access()" device-mapper no longer allows dax operation. This results from the stricter checks in __bdev_dax_supported() that validate that the start and end of a block-device map to the same 'pagemap' instance. Teach the dax-core and device-mapper to validate the 'pagemap' on a per-target basis. This is accomplished by refactoring the bdev_dax_supported() internals into generic_fsdax_supported() which takes a sector range to validate. Consequently generic_fsdax_supported() is suitable to be used in a device-mapper ->iterate_devices() callback. A new ->dax_supported() operation is added to allow composite devices to split and route upper-level bdev_dax_supported() requests. Fixes: ad428cdb525a ("dax: Check the end of the block-device...") Cc: <stable@vger.kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Reported-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Tested-by: Pankaj Gupta <pagupta@redhat.com> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-12-04dax: Fix unlock mismatch with updated APIMatthew Wilcox1-6/+8
Internal to dax_unlock_mapping_entry(), dax_unlock_entry() is used to store a replacement entry in the Xarray at the given xas-index with the DAX_LOCKED bit clear. When called, dax_unlock_entry() expects the unlocked value of the entry relative to the current Xarray state to be specified. In most contexts dax_unlock_entry() is operating in the same scope as the matched dax_lock_entry(). However, in the dax_unlock_mapping_entry() case the implementation needs to recall the original entry. In the case where the original entry is a 'pmd' entry it is possible that the pfn performed to do the lookup is misaligned to the value retrieved in the Xarray. Change the api to return the unlock cookie from dax_lock_page() and pass it to dax_unlock_page(). This fixes a bug where dax_unlock_page() was assuming that the page was PMD-aligned if the entry was a PMD entry with signatures like: WARNING: CPU: 38 PID: 1396 at fs/dax.c:340 dax_insert_entry+0x2b2/0x2d0 RIP: 0010:dax_insert_entry+0x2b2/0x2d0 [..] Call Trace: dax_iomap_pte_fault.isra.41+0x791/0xde0 ext4_dax_huge_fault+0x16f/0x1f0 ? up_read+0x1c/0xa0 __do_fault+0x1f/0x160 __handle_mm_fault+0x1033/0x1490 handle_mm_fault+0x18b/0x3d0 Link: https://lkml.kernel.org/r/20181130154902.GL10377@bombadil.infradead.org Fixes: 9f32d221301c ("dax: Convert dax_lock_mapping_entry to XArray") Reported-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Matthew Wilcox <willy@infradead.org> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-07-23filesystem-dax: Introduce dax_lock_mapping_entry()Dan Williams1-0/+13
In preparation for implementing support for memory poison (media error) handling via dax mappings, implement a lock_page() equivalent. Poison error handling requires rmap and needs guarantees that the page->mapping association is maintained / valid (inode not freed) for the duration of the lookup. In the device-dax case it is sufficient to simply hold a dev_pagemap reference. In the filesystem-dax case we need to use the entry lock. Export the entry lock via dax_lock_mapping_entry() that uses rcu_read_lock() to protect against the inode being freed, and revalidates the page->mapping association under xa_lock(). Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-06-28include/linux/dax.h: dax_iomap_fault() returns vm_fault_tSouptick Joarder1-1/+1
Commit 1c8f422059ae ("mm: change return type to vm_fault_t") missed a conversion. It's not a big problem at present because mainline is still using typedef int vm_fault_t; Fixes: 1c8f422059ae ("mm: change return type to vm_fault_t") Link: http://lkml.kernel.org/r/20180620172046.GA27894@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-08Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds1-0/+12
Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
2018-06-08Merge branch 'for-4.18/mcsafe' into libnvdimm-for-nextDan Williams1-0/+5
2018-06-07fs/dax.c: use new return type vm_fault_tSouptick Joarder1-2/+2
Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. commit 1c8f422059ae ("mm: change return type to vm_fault_t") There was an existing bug inside dax_load_hole() if vm_insert_mixed had failed to allocate a page table, we'd return VM_FAULT_NOPAGE instead of VM_FAULT_OOM. With new vmf_insert_mixed() this issue is addressed. vm_insert_mixed_mkwrite has inefficiency when it returns an error value, driver has to convert it to vm_fault_t type. With new vmf_insert_mixed_mkwrite() this limitation will be addressed. Link: http://lkml.kernel.org/r/20180510181121.GA15239@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-31dax: change bdev_dax_supported() to support boolean returnsDave Jiang1-4/+4
The function return values are confusing with the way the function is named. We expect a true or false return value but it actually returns 0/-errno. This makes the code very confusing. Changing the return values to return a bool where if DAX is supported then return true and no DAX support returns false. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-31fs: allow per-device dax status checking for filesystemsDarrick J. Wong1-4/+5
Change bdev_dax_supported so it takes a bdev parameter. This enables multi-device filesystems like xfs to check that a dax device can work for the particular filesystem. Once that's in place, actually fix all the parts of XFS where we need to be able to distinguish between datadev and rtdev. This patch fixes the problem where we screw up the dax support checking in xfs if the datadev and rtdev have different dax capabilities. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [rez: Re-added __bdev_dax_supported() for !CONFIG_FS_DAX cases] Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2018-05-22dax: Introduce a ->copy_to_iter dax operationDan Williams1-0/+5
Similar to the ->copy_from_iter() operation, a platform may want to deploy an architecture or device specific routine for handling reads from a dax_device like /dev/pmemX. On x86 this routine will point to a machine check safe version of copy_to_iter(). For now, add the plumbing to device-mapper and the dax core. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>