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2020-06-09Merge tag 'ovl-update-5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "Fixes: - Resolve mount option conflicts consistently - Sync before remount R/O - Fix file handle encoding corner cases - Fix metacopy related issues - Fix an unintialized return value - Add missing permission checks for underlying layers Optimizations: - Allow multipe whiteouts to share an inode - Optimize small writes by inheriting SB_NOSEC from upper layer - Do not call ->syncfs() multiple times for sync(2) - Do not cache negative lookups on upper layer - Make private internal mounts longterm" * tag 'ovl-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (27 commits) ovl: remove unnecessary lock check ovl: make oip->index bool ovl: only pass ->ki_flags to ovl_iocb_to_rwf() ovl: make private mounts longterm ovl: get rid of redundant members in struct ovl_fs ovl: add accessor for ofs->upper_mnt ovl: initialize error in ovl_copy_xattr ovl: drop negative dentry in upper layer ovl: check permission to open real file ovl: call secutiry hook in ovl_real_ioctl() ovl: verify permissions in ovl_path_open() ovl: switch to mounter creds in readdir ovl: pass correct flags for opening real directory ovl: fix redirect traversal on metacopy dentries ovl: initialize OVL_UPPERDATA in ovl_lookup() ovl: use only uppermetacopy state in ovl_lookup() ovl: simplify setting of origin for index lookup ovl: fix out of bounds access warning in ovl_check_fb_len() ovl: return required buffer size for file handles ovl: sync dirty data when remounting to ro mode ...
2020-06-02vfs: track per-sb writeback errors and report them to syncfsJeff Layton
Patch series "vfs: have syncfs() return error when there are writeback errors", v6. Currently, syncfs does not return errors when one of the inodes fails to be written back. It will return errors based on the legacy AS_EIO and AS_ENOSPC flags when syncing out the block device fails, but that's not particularly helpful for filesystems that aren't backed by a blockdev. It's also possible for a stray sync to lose those errors. The basic idea in this set is to track writeback errors at the superblock level, so that we can quickly and easily check whether something bad happened without having to fsync each file individually. syncfs is then changed to reliably report writeback errors after they occur, much in the same fashion as fsync does now. This patch (of 2): Usually we suggest that applications call fsync when they want to ensure that all data written to the file has made it to the backing store, but that can be inefficient when there are a lot of open files. Calling syncfs on the filesystem can be more efficient in some situations, but the error reporting doesn't currently work the way most people expect. If a single inode on a filesystem reports a writeback error, syncfs won't necessarily return an error. syncfs only returns an error if __sync_blockdev fails, and on some filesystems that's a no-op. It would be better if syncfs reported an error if there were any writeback failures. Then applications could call syncfs to see if there are any errors on any open files, and could then call fsync on all of the other descriptors to figure out which one failed. This patch adds a new errseq_t to struct super_block, and has mapping_set_error also record writeback errors there. To report those errors, we also need to keep an errseq_t in struct file to act as a cursor. This patch adds a dedicated field for that purpose, which slots nicely into 4 bytes of padding at the end of struct file on x86_64. An earlier version of this patch used an O_PATH file descriptor to cue the kernel that the open file should track the superblock error and not the inode's writeback error. I think that API is just too weird though. This is simpler and should make syncfs error reporting "just work" even if someone is multiplexing fsync and syncfs on the same fds. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Andres Freund <andres@anarazel.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20200428135155.19223-1-jlayton@kernel.org Link: http://lkml.kernel.org/r/20200428135155.19223-2-jlayton@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-13ovl: skip overlayfs superblocks at global syncKonstantin Khlebnikov
Stacked filesystems like overlayfs has no own writeback, but they have to forward syncfs() requests to backend for keeping data integrity. During global sync() each overlayfs instance calls method ->sync_fs() for backend although it itself is in global list of superblocks too. As a result one syscall sync() could write one superblock several times and send multiple disk barriers. This patch adds flag SB_I_SKIP_SYNC into sb->sb_iflags to avoid that. Reported-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-05-14fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writebackAmir Goldstein
23d0127096cb ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE writeback") claims that sync_file_range(2) syscall was "created for userspace to be able to issue background writeout and so waiting for in-flight IO is undesirable there" and changes the writeback (back) to WB_SYNC_NONE. This claim is only partially true. It is true for users that use the flag SYNC_FILE_RANGE_WRITE by itself, as does PostgreSQL, the user that was the reason for changing to WB_SYNC_NONE writeback. However, that claim is not true for users that use that flag combination SYNC_FILE_RANGE_{WAIT_BEFORE|WRITE|_WAIT_AFTER}. Those users explicitly requested to wait for in-flight IO as well as to writeback of dirty pages. Re-brand that flag combination as SYNC_FILE_RANGE_WRITE_AND_WAIT and use WB_SYNC_ALL writeback to perform the full range sync request. Link: http://lkml.kernel.org/r/20190409114922.30095-1-amir73il@gmail.com Link: http://lkml.kernel.org/r/20190419072938.31320-1-amir73il@gmail.com Fixes: 23d0127096cb ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Acked-by: Jan Kara <jack@suse.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-02fs: add sync_file_range() helperJens Axboe
This just pulls out the ksys_sync_file_range() code to work on a struct file instead of an fd, so we can use it elsewhere. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-04Merge tag 'xfs-4.17-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs updates from Darrick Wong: "Here's the first round of fixes for XFS for 4.17. The biggest new features this time around are the addition of lazytime support, further enhancement of the on-disk inode metadata verifiers, and a patch to smooth over some of the AGFL padding problems that have intermittently plagued users since 4.5. I forsee sending a second pull request next week with further bug fixes and speedups in the online scrub code and elsewhere. This series has been run through a full xfstests run over the weekend and through a quick xfstests run against this morning's master, with no major failures reported. Summary of changes for this release: - Various cleanups and code fixes - Implement lazytime as a mount option - Convert various on-disk metadata checks from asserts to -EFSCORRUPTED - Fix accounting problems with the rmap per-ag reservations - Refactorings and cleanups for xfs_log_force - Various bugfixes for the reflink code - Work around v5 AGFL padding problems to prevent fs shutdowns - Establish inode fork verifiers to inspect on-disk metadata correctness - Various online scrub fixes - Fix v5 swapext blowing up on deleted inodes" * tag 'xfs-4.17-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (49 commits) xfs: do not log/recover swapext extent owner changes for deleted inodes xfs: clean up xfs_mount allocation and dynamic initializers xfs: remove dead inode version setting code xfs: catch inode allocation state mismatch corruption xfs: xfs_scrub_iallocbt_xref_rmap_inodes should use xref_set_corrupt xfs: flag inode corruption if parent ptr doesn't get us a real inode xfs: don't accept inode buffers with suspicious unlinked chains xfs: move inode extent size hint validation to libxfs xfs: record inode buf errors as a xref error in inobt scrubber xfs: remove xfs_buf parameter from inode scrub methods xfs: inode scrubber shouldn't bother with raw checks xfs: bmap scrubber should do rmap xref with bmap for sparse files xfs: refactor inode buffer verifier error logging xfs: refactor inode verifier error logging xfs: refactor bmap record validation xfs: sanity-check the unused space before trying to use it xfs: detect agfl count corruption and reset agfl xfs: unwind the try_again loop in xfs_log_force xfs: refactor xfs_log_force_lsn xfs: minor cleanup for xfs_reflink_end_cow ...
2018-04-02fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscallDominik Brodowski
Using this helper allows us to avoid the in-kernel calls to the sys_sync_file_range() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_sync_file_range(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02fs: add ksys_sync() helper; remove in-kernel calls to sys_sync()Dominik Brodowski
Using this helper allows us to avoid the in-kernel calls to the sys_sync() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_sync(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-03-11fs: don't clear I_DIRTY_TIME before calling mark_inode_dirty_syncChristoph Hellwig
__mark_inode_dirty already takes care of that, and for the XFS lazytime implementation we need to know that ->dirty_inode was called because I_DIRTY_TIME was set. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-03fs: kill 'nr_pages' argument from wakeup_flusher_threads()Jens Axboe
Everybody is passing in 0 now, let's get rid of the argument. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-14Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \ -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \ -e 's/\<MS_NODEV\>/SB_NODEV/g' \ -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \ -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \ -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \ -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \ -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \ -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \ -e 's/\<MS_SILENT\>/SB_SILENT/g' \ -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \ -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \ -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \ -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - various misc bits - DAX updates - OCFS2 - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits) mm,fork: introduce MADV_WIPEONFORK x86,mpx: make mpx depend on x86-64 to free up VMA flag mm: add /proc/pid/smaps_rollup mm: hugetlb: clear target sub-page last when clearing huge page mm: oom: let oom_reap_task and exit_mmap run concurrently swap: choose swap device according to numa node mm: replace TIF_MEMDIE checks by tsk_is_oom_victim mm, oom: do not rely on TIF_MEMDIE for memory reserves access z3fold: use per-cpu unbuddied lists mm, swap: don't use VMA based swap readahead if HDD is used as swap mm, swap: add sysfs interface for VMA based swap readahead mm, swap: VMA based swap readahead mm, swap: fix swap readahead marking mm, swap: add swap readahead hit statistics mm/vmalloc.c: don't reinvent the wheel but use existing llist API mm/vmstat.c: fix wrong comment selftests/memfd: add memfd_create hugetlbfs selftest mm/shmem: add hugetlbfs support to memfd_create() mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas() ...
2017-09-06fs/sync.c: remove unnecessary NULL f_mapping check in sync_file_rangeJeff Layton
fsync codepath assumes that f_mapping can never be NULL, but sync_file_range has a check for that. Remove the one from sync_file_range as I don't see how you'd ever get a NULL pointer in here. Link: http://lkml.kernel.org/r/20170525110509.9434-1-jlayton@redhat.com Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-01fs: convert sync_file_range to use errseq_t based error-trackingJeff Layton
sync_file_range doesn't call down into the filesystem directly at all. It only kicks off writeback of pagecache pages and optionally waits on the result. Convert sync_file_range to use errseq_t based error tracking, under the assumption that most users will prefer this behavior when errors occur. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-17VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)David Howells
Firstly by applying the following with coccinelle's spatch: @@ expression SB; @@ -SB->s_flags & MS_RDONLY +sb_rdonly(SB) to effect the conversion to sb_rdonly(sb), then by applying: @@ expression A, SB; @@ ( -(!sb_rdonly(SB)) && A +!sb_rdonly(SB) && A | -A != (sb_rdonly(SB)) +A != sb_rdonly(SB) | -A == (sb_rdonly(SB)) +A == sb_rdonly(SB) | -!(sb_rdonly(SB)) +!sb_rdonly(SB) | -A && (sb_rdonly(SB)) +A && sb_rdonly(SB) | -A || (sb_rdonly(SB)) +A || sb_rdonly(SB) | -(sb_rdonly(SB)) != A +sb_rdonly(SB) != A | -(sb_rdonly(SB)) == A +sb_rdonly(SB) == A | -(sb_rdonly(SB)) && A +sb_rdonly(SB) && A | -(sb_rdonly(SB)) || A +sb_rdonly(SB) || A ) @@ expression A, B, SB; @@ ( -(sb_rdonly(SB)) ? 1 : 0 +sb_rdonly(SB) | -(sb_rdonly(SB)) ? A : B +sb_rdonly(SB) ? A : B ) to remove left over excess bracketage and finally by applying: @@ expression A, SB; @@ ( -(A & MS_RDONLY) != sb_rdonly(SB) +(bool)(A & MS_RDONLY) != sb_rdonly(SB) | -(A & MS_RDONLY) == sb_rdonly(SB) +(bool)(A & MS_RDONLY) == sb_rdonly(SB) ) to make comparisons against the result of sb_rdonly() (which is a bool) work correctly. Signed-off-by: David Howells <dhowells@redhat.com>
2017-07-05fs: remove call_fsync helper functionJeff Layton
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-02-20vfs: use helper for calling f_op->fsync()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE writebackJan Kara
sync_file_range(2) is documented to issue writeback only for pages that are not currently being written. After all the system call has been created for userspace to be able to issue background writeout and so waiting for in-flight IO is undesirable there. However commit ee53a891f474 ("mm: do_sync_mapping_range integrity fix") switched do_sync_mapping_range() and thus sync_file_range() to issue writeback in WB_SYNC_ALL mode since do_sync_mapping_range() was used by other code relying on WB_SYNC_ALL semantics. These days do_sync_mapping_range() went away and we can switch sync_file_range(2) back to issuing WB_SYNC_NONE writeback. That should help PostgreSQL avoid large latency spikes when flushing data in the background. Andres measured a 20% increase in transactions per second on an SSD disk. Signed-off-by: Jan Kara <jack@suse.com> Reported-by: Andres Freund <andres@anarazel.de> Tested-By: Andres Freund <andres@anarazel.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05mm/filemap.c: make global sync not clear error status of individual inodesJunichi Nomura
filemap_fdatawait() is a function to wait for on-going writeback to complete but also consume and clear error status of the mapping set during writeback. The latter functionality is critical for applications to detect writeback error with system calls like fsync(2)/fdatasync(2). However filemap_fdatawait() is also used by sync(2) or FIFREEZE ioctl, which don't check error status of individual mappings. As a result, fsync() may not be able to detect writeback error if events happen in the following order: Application System admin ---------------------------------------------------------- write data on page cache Run sync command writeback completes with error filemap_fdatawait() clears error fsync returns success (but the data is not on disk) This patch adds filemap_fdatawait_keep_errors() for call sites where writeback error is not handled so that they don't clear error status. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Fengguang Wu <fengguang.wu@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-05vfs: add support for a lazytime mount optionTheodore Ts'o
Add a new mount option which enables a new "lazytime" mode. This mode causes atime, mtime, and ctime updates to only be made to the in-memory version of the inode. The on-disk times will only get updated when (a) if the inode needs to be updated for some non-time related change, (b) if userspace calls fsync(), syncfs() or sync(), or (c) just before an undeleted inode is evicted from memory. This is OK according to POSIX because there are no guarantees after a crash unless userspace explicitly requests via a fsync(2) call. For workloads which feature a large number of random write to a preallocated file, the lazytime mount option significantly reduces writes to the inode table. The repeated 4k writes to a single block will result in undesirable stress on flash devices and SMR disk drives. Even on conventional HDD's, the repeated writes to the inode table block will trigger Adjacent Track Interference (ATI) remediation latencies, which very negatively impact long tail latencies --- which is a very big deal for web serving tiers (for example). Google-Bug-Id: 18297052 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19kill f_dentry usesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-09-05Export sync_filesystem() for modular ->remount_fs() useAnton Altaparmakov
This patch changes sync_filesystem() to be EXPORT_SYMBOL(). The reason this is needed is that starting with 3.15 kernel, due to Theodore Ts'o's commit 02b9984d6408 ("fs: push sync_filesystem() down to the file system's remount_fs()"), all file systems that have dirty data to be written out need to call sync_filesystem() from their ->remount_fs() method when remounting read-only. As this is now a generically required function rather than an internal only function it should be EXPORT_SYMBOL() so that all file systems can call it. Signed-off-by: Anton Altaparmakov <aia21@cantab.net> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-22Revert "writeback: do not sync data dirtied after sync start"Jan Kara
This reverts commit c4a391b53a72d2df4ee97f96f78c1d5971b47489. Dave Chinner <david@fromorbit.com> has reported the commit may cause some inodes to be left out from sync(2). This is because we can call redirty_tail() for some inode (which sets i_dirtied_when to current time) after sync(2) has started or similarly requeue_inode() can set i_dirtied_when to current time if writeback had to skip some pages. The real problem is in the functions clobbering i_dirtied_when but fixing that isn't trivial so revert is a safer choice for now. CC: stable@vger.kernel.org # >= 3.13 Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-09fix O_SYNC|O_APPEND syncing the wrong range on write()Al Viro
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support) when sync_page_range() had been introduced; generic_file_write{,v}() correctly synced pos_after_write - written .. pos_after_write - 1 but generic_file_aio_write() synced pos_before_write .. pos_before_write + written - 1 instead. Which is not the same thing with O_APPEND, obviously. A couple of years later correct variant had been killed off when everything switched to use of generic_file_aio_write(). All users of generic_file_aio_write() are affected, and the same bug has been copied into other instances of ->aio_write(). The fix is trivial; the only subtle point is that generic_write_sync() ought to be inlined to avoid calculations useless for the majority of calls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-13Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge first patch-bomb from Andrew Morton: "Quite a lot of other stuff is banked up awaiting further next->mainline merging, but this batch contains: - Lots of random misc patches - OCFS2 - Most of MM - backlight updates - lib/ updates - printk updates - checkpatch updates - epoll tweaking - rtc updates - hfs - hfsplus - documentation - procfs - update gcov to gcc-4.7 format - IPC" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits) ipc, msg: fix message length check for negative values ipc/util.c: remove unnecessary work pending test devpts: plug the memory leak in kill_sb ./Makefile: export initial ramdisk compression config option init/Kconfig: add option to disable kernel compression drivers: w1: make w1_slave::flags long to avoid memory corruption drivers/w1/masters/ds1wm.cuse dev_get_platdata() drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page() drivers/memstick/core/mspro_block.c: fix attributes array allocation drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr kernel/panic.c: reduce 1 byte usage for print tainted buffer gcov: reuse kbasename helper kernel/gcov/fs.c: use pr_warn() kernel/module.c: use pr_foo() gcov: compile specific gcov implementation based on gcc version gcov: add support for gcc 4.7 gcov format gcov: move gcov structs definitions to a gcc version specific file kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener() kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end() kernel/sysctl_binary.c: use scnprintf() instead of snprintf() ...
2013-11-13writeback: do not sync data dirtied after sync startJan Kara
When there are processes heavily creating small files while sync(2) is running, it can easily happen that quite some new files are created between WB_SYNC_NONE and WB_SYNC_ALL pass of sync(2). That can happen especially if there are several busy filesystems (remember that sync traverses filesystems sequentially and waits in WB_SYNC_ALL phase on one fs before starting it on another fs). Because WB_SYNC_ALL pass is slow (e.g. causes a transaction commit and cache flush for each inode in ext3), resulting sync(2) times are rather large. The following script reproduces the problem: function run_writers { for (( i = 0; i < 10; i++ )); do mkdir $1/dir$i for (( j = 0; j < 40000; j++ )); do dd if=/dev/zero of=$1/dir$i/$j bs=4k count=4 &>/dev/null done & done } for dir in "$@"; do run_writers $dir done sleep 40 time sync Fix the problem by disregarding inodes dirtied after sync(2) was called in the WB_SYNC_ALL pass. To allow for this, sync_inodes_sb() now takes a time stamp when sync has started which is used for setting up work for flusher threads. To give some numbers, when above script is run on two ext4 filesystems on simple SATA drive, the average sync time from 10 runs is 267.549 seconds with standard deviation 104.799426. With the patched kernel, the average sync time from 10 runs is 2.995 seconds with standard deviation 0.096. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-24file->f_op is never NULL...Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-03teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long longAl Viro
... and convert a bunch of SYSCALL_DEFINE ones to SYSCALL_DEFINE<n>, killing the boilerplate crap around them. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26switch simple cases of fget_light to fdgetAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder ↵Jan Kara
sync passes wakeup_flusher_threads(0) will queue work doing complete writeback for each flusher thread. Thus there is not much point in submitting another work doing full inode WB_SYNC_NONE writeback by writeback_inodes_sb(). After this change it does not make sense to call nonblocking ->sync_fs and block device flush before calling sync_inodes_sb() because wakeup_flusher_threads() is completely asynchronous and thus these functions would be called in parallel with inode writeback running which will effectively void any work they do. So we move sync_inodes_sb() call before these two functions. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22vfs: Remove unnecessary flushing of block devicesJan Kara
It is not necessary to write block devices twice. The reason why we first did flush and then proper sync is that for_each_bdev() { write_bdev() wait_for_completion() } is much slower than for_each_bdev() write_bdev() for_each_bdev() wait_for_completion() when there is bigger amount of data. But as is seen in the above, there's no real need to scan pages and submit them twice. We just need to separate the submission and waiting part. This patch does that. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22vfs: Make sys_sync writeout also block device inodesJan Kara
In case block device does not have filesystem mounted on it, sys_sync will just ignore it and doesn't writeout its dirty pages. This is because writeback code avoids writing inodes from superblock without backing device and blockdev_superblock is such a superblock. Since it's unexpected that sync doesn't writeout dirty data for block devices be nice to users and change the behavior to do so. So now we iterate over all block devices on blockdev_super instead of iterating over all superblocks when syncing block devices. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22vfs: Reorder operations during sys_syncJan Kara
Change the order of operations during sync from for_each_sb { writeback_inodes_sb(); sync_fs(nowait); __sync_blockdev(nowait); } for_each_sb { sync_inodes_sb(); sync_fs(wait); __sync_blockdev(wait); } to for_each_sb writeback_inodes_sb(); for_each_sb sync_fs(nowait); for_each_sb __sync_blockdev(nowait); for_each_sb sync_inodes_sb(); for_each_sb sync_fs(wait); for_each_sb __sync_blockdev(wait); This is a preparation for the following patches in this series. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22quota: Move quota syncing to ->sync_fs methodJan Kara
Since the moment writes to quota files are using block device page cache and space for quota structures is reserved at the moment they are first accessed we have no reason to sync quota before inode writeback. In fact this order is now only harmful since quota information can easily change during inode writeback (either because conversion of delayed-allocated extents or simply because of allocation of new blocks for simple filesystems not using page_mkwrite). So move syncing of quota information after writeback of inodes into ->sync_fs method. This way we do not have to use ->quota_sync callback which is primarily intended for use by quotactl syscall anyway and we get rid of calling ->sync_fs() twice unnecessarily. We skip quota syncing for OCFS2 since it does proper quota journalling in all cases (unlike ext3, ext4, and reiserfs which also support legacy non-journalled quotas) and thus there are no dirty quota structures. CC: "Theodore Ts'o" <tytso@mit.edu> CC: Joel Becker <jlbec@evilplan.org> CC: reiserfs-devel@vger.kernel.org Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Dave Kleikamp <shaggy@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22quota: Split dquot_quota_sync() to writeback and cache flushing partJan Kara
Split off part of dquot_quota_sync() which writes dquots into a quota file to a separate function. In the next patch we will use the function from filesystems and we do not want to abuse ->quota_sync quotactl callback more than necessary. Acked-by: Steven Whitehouse <swhiteho@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22vfs: Move noop_backing_dev_info check from sync into writebackJan Kara
In principle, a filesystem may want to have ->sync_fs() called during sync(1) although it does not have a bdi (i.e. s_bdi is set to noop_backing_dev_info). Only writeback code really needs bdi set to something reasonable. So move the checks where they are more logical. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29switch do_fsync() to fget_light()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-28fs: reduce the use of module.h wherever possiblePaul Gortmaker
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-01-03fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-31writeback: Add a 'reason' to wb_writeback_workCurt Wohlgemuth
This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-07-20fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlersJosef Bacik
Btrfs needs to be able to control how filemap_write_and_wait_range() is called in fsync to make it less of a painful operation, so push down taking i_mutex and the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some file systems can drop taking the i_mutex altogether it seems, like ext3 and ocfs2. For correctness sake I just pushed everything down in all cases to make sure that we keep the current behavior the same for everybody, and then each individual fs maintainer can make up their mind about what to do from there. Thanks, Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
2011-03-21introduce sys_syncfs to sync a single file systemSage Weil
It is frequently useful to sync a single file system, instead of all mounted file systems via sync(2): - On machines with many mounts, it is not at all uncommon for some of them to hang (e.g. unresponsive NFS server). sync(2) will get stuck on those and may never get to the one you do care about (e.g., /). - Some applications write lots of data to the file system and then want to make sure it is flushed to disk. Calling fsync(2) on each file introduces unnecessary ordering constraints that result in a large amount of sub-optimal writeback/flush/commit behavior by the file system. There are currently two ways (that I know of) to sync a single super_block: - BLKFLSBUF ioctl on the block device: That also invalidates the bdev mapping, which isn't usually desirable, and doesn't work for non-block file systems. - 'mount -o remount,rw' will call sync_filesystem as an artifact of the current implemention. Relying on this little-known side effect for something like data safety sounds foolish. Both of these approaches require root privileges, which some applications do not have (nor should they need?) given that sync(2) is an unprivileged operation. This patch introduces a new system call syncfs(2) that takes an fd and syncs only the file system it references. Maybe someday we can $ sync /some/path and not get sync: ignoring all arguments The syscall is motivated by comments by Al and Christoph at the last LSF. syncfs(2) seems like an appropriate name given statfs(2). A similar ioctl was also proposed a while back, see http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2 Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-17fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going awayJens Axboe
We don't have proper reference counting for this yet, so we run into cases where the device is pulled and we OOPS on flushing the fs data. This happens even though the dirty inodes have already been migrated to the default_backing_dev_info. Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com> Tested-by: Torsten Hilbrich <torsten.hilbrich@secunet.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-09get rid of file_fsync()Al Viro
Copy and simplify in the only two users remaining. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-01Merge branch 'master' into for-linusJens Axboe
Conflicts: fs/pipe.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>