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2018-07-17ovl: fix wrong use of impure dir cache in ovl_iterate()Amir Goldstein
Only upper dir can be impure, but if we are in the middle of iterating a lower real dir, dir could be copied up and marked impure. We only want the impure cache if we started iterating a real upper dir to begin with. Aditya Kali reported that the following reproducer hits the WARN_ON(!cache->refcount) in ovl_get_cache(): docker run --rm drupal:8.5.4-fpm-alpine \ sh -c 'cd /var/www/html/vendor/symfony && \ chown -R www-data:www-data . && ls -l .' Reported-by: Aditya Kali <adityakali@google.com> Tested-by: Aditya Kali <adityakali@google.com> Fixes: 4edb83bb1041 ('ovl: constant d_ino for non-merge dirs') Cc: <stable@vger.kernel.org> # v4.14 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-17configfs: fix registered group removalMike Christie
This patch fixes a bug where configfs_register_group had added a group in a tree, and userspace has done a rmdir on a dir somewhere above that group and we hit a kernel crash. The problem is configfs_rmdir will detach everything under it and unlink groups on the default_groups list. It will not unlink groups added with configfs_register_group so when configfs_unregister_group is called to drop its references to the group/items we crash when we try to access the freed dentrys. The patch just adds a check for if a rmdir has been done above us and if so just does the unlink part of unregistration. Sorry if you are getting this multiple times. I thouhgt I sent this to some of you and lkml, but I do not see it. Signed-off-by: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-07-17btrfs: scrub: Don't use inode page cache in scrub_handle_errored_block()Qu Wenruo
In commit ac0b4145d662 ("btrfs: scrub: Don't use inode pages for device replace") we removed the branch of copy_nocow_pages() to avoid corruption for compressed nodatasum extents. However above commit only solves the problem in scrub_extent(), if during scrub_pages() we failed to read some pages, sctx->no_io_error_seen will be non-zero and we go to fixup function scrub_handle_errored_block(). In scrub_handle_errored_block(), for sctx without csum (no matter if we're doing replace or scrub) we go to scrub_fixup_nodatasum() routine, which does the similar thing with copy_nocow_pages(), but does it without the extra check in copy_nocow_pages() routine. So for test cases like btrfs/100, where we emulate read errors during replace/scrub, we could corrupt compressed extent data again. This patch will fix it just by avoiding any "optimization" for nodatasum, just falls back to the normal fixup routine by try read from any good copy. This also solves WARN_ON() or dead lock caused by lame backref iteration in scrub_fixup_nodatasum() routine. The deadlock or WARN_ON() won't be triggered before commit ac0b4145d662 ("btrfs: scrub: Don't use inode pages for device replace") since copy_nocow_pages() have better locking and extra check for data extent, and it's already doing the fixup work by try to read data from any good copy, so it won't go scrub_fixup_nodatasum() anyway. This patch disables the faulty code and will be removed completely in a followup patch. Fixes: ac0b4145d662 ("btrfs: scrub: Don't use inode pages for device replace") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-17Merge tag 'v4.18-rc5' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15f2fs: do checkpoint in kill_sbJaegeuk Kim
When unmounting f2fs in force mode, we can get it stuck by io_schedule() by some pending IOs in meta_inode. io_schedule+0xd/0x30 wait_on_page_bit_common+0xc6/0x130 __filemap_fdatawait_range+0xbd/0x100 filemap_fdatawait_keep_errors+0x15/0x40 sync_inodes_sb+0x1cf/0x240 sync_filesystem+0x52/0x90 generic_shutdown_super+0x1d/0x110 kill_f2fs_super+0x28/0x80 [f2fs] deactivate_locked_super+0x35/0x60 cleanup_mnt+0x36/0x70 task_work_run+0x79/0xa0 exit_to_usermode_loop+0x62/0x70 do_syscall_64+0xdb/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 0xffffffffffffffff Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-07-15f2fs: allow wrong configured dio to buffered writeJaegeuk Kim
This fixes to support dio having unaligned buffers as buffered writes. xfs_io -f -d -c "pwrite 0 512" $testfile -> okay xfs_io -f -d -c "pwrite 1 512" $testfile -> EINVAL Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-07-14reiserfs: fix buffer overflow with long warning messagesEric Biggers
ReiserFS prepares log messages into a 1024-byte buffer with no bounds checks. Long messages, such as the "unknown mount option" warning when userspace passes a crafted mount options string, overflow this buffer. This causes KASAN to report a global-out-of-bounds write. Fix it by truncating messages to the buffer size. Link: http://lkml.kernel.org/r/20180707203621.30922-1-ebiggers3@gmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+b890b3335a4d8c608963@syzkaller.appspotmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14fs, elf: make sure to page align bss in load_elf_libraryOscar Salvador
The current code does not make sure to page align bss before calling vm_brk(), and this can lead to a VM_BUG_ON() in __mm_populate() due to the requested lenght not being correctly aligned. Let us make sure to align it properly. Kees: only applicable to CONFIG_USELIB kernels: 32-bit and configured for libc5. Link: http://lkml.kernel.org/r/20180705145539.9627-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Kees Cook <keescook@chromium.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14autofs: fix slab out of bounds read in getname_kernel()Tomas Bortoli
The autofs subsystem does not check that the "path" parameter is present for all cases where it is required when it is passed in via the "param" struct. In particular it isn't checked for the AUTOFS_DEV_IOCTL_OPENMOUNT_CMD ioctl command. To solve it, modify validate_dev_ioctl(function to check that a path has been provided for ioctl commands that require it. Link: http://lkml.kernel.org/r/153060031527.26631.18306637892746301555.stgit@pluto.themaw.net Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Reported-by: syzbot+60c837b428dc84e83a93@syzkaller.appspotmail.com Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-14fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps*Vlastimil Babka
Thomas reports: "While looking around in /proc on my v4.14.52 system I noticed that all processes got a lot of "Locked" memory in /proc/*/smaps. A lot more memory than a regular user can usually lock with mlock(). Commit 493b0e9d945f (in v4.14-rc1) seems to have changed the behavior of "Locked". Before that commit the code was like this. Notice the VM_LOCKED check. (vma->vm_flags & VM_LOCKED) ? (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); After that commit Locked is now the same as Pss: (unsigned long)(mss->pss >> (10 + PSS_SHIFT))); This looks like a mistake." Indeed, the commit has added mss->pss_locked with the correct value that depends on VM_LOCKED, but forgot to actually use it. Fix it. Link: http://lkml.kernel.org/r/ebf6c7fb-fec3-6a26-544f-710ed193c154@suse.cz Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Daniel Colascione <dancol@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-13btrfs: fix use-after-free of cmp workspace pagesNaohiro Aota
btrfs_cmp_data_free() puts cmp's src_pages and dst_pages, but leaves their page address intact. Now, if you hit "goto again" in btrfs_extent_same_range() and hit some error in btrfs_cmp_data_prepare(), you'll try to unlock/put already put pages. This is simple fix to reset the address to avoid use-after-free. Fixes: 67b07bd4bec5 ("Btrfs: reuse cmp workspace in EXTENT_SAME ioctl") Signed-off-by: Naohiro Aota <naota@elisp.net> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-13btrfs: restore uuid_mutex in btrfs_open_devicesDavid Sterba
Commit 542c5908abfe84f7b4c1 ("btrfs: replace uuid_mutex by device_list_mutex in btrfs_open_devices") switched to device_list_mutex as we need that for the device list traversal, but we also need uuid_mutex to protect access to fs_devices::opened to be consistent with other users of that. Fixes: 542c5908abfe84f7b4c1 ("btrfs: replace uuid_mutex by device_list_mutex in btrfs_open_devices") Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-12ext4: check for allocation block validity with block group lockedTheodore Ts'o
With commit 044e6e3d74a3: "ext4: don't update checksum of new initialized bitmaps" the buffer valid bit will get set without actually setting up the checksum for the allocation bitmap, since the checksum will get calculated once we actually allocate an inode or block. If we are doing this, then we need to (re-)check the verified bit after we take the block group lock. Otherwise, we could race with another process reading and verifying the bitmap, which would then complain about the checksum being invalid. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1780137 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2018-07-12Merge branch 'fortglx/4.19/time' of ↵Thomas Gleixner
https://git.linaro.org/people/john.stultz/linux into timers/core Pull timekeeping updates from John Stultz: - Make the timekeeping update more precise when NTP frequency is set directly by updating the multiplier. - Adjust selftests
2018-07-12new helper: open_with_fake_path()Al Viro
open a file by given inode, faking ->f_path. Use with shitloads of caution - at the very least you'd damn better make sure that some dentry alias of that inode is pinned down by the path in question. Again, this is no general-purpose interface and I hope it will eventually go away. Right now overlayfs wants something like that, but nothing else should. Any out-of-tree code with bright idea of using this one *will* eventually get hurt, with zero notice and great delight on my part. I refuse to use EXPORT_SYMBOL_GPL(), especially in situations when it's really EXPORT_SYMBOL_DONT_USE_IT(), but don't take that export as "you are welcome to use it". Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12few more cleanups of link_path_walk() callersAl Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12allow link_path_walk() to take ERR_PTR()Al Viro
There is a check for IS_ERR(name) immediately upstream of each call of link_path_walk(name, nd), with positives treated as if link_path_walk() failed with PTR_ERR(name). Taking that check into link_path_walk() itself simplifies things nicely. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12make path_init() unconditionally paired with terminate_walk()Al Viro
including the failure exits Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12make alloc_file() staticAl Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12new helper: alloc_file_clone()Al Viro
alloc_file_clone(old_file, mode, ops): create a new struct file with ->f_path equal to that of old_file. pipe converted. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12create_pipe_files(): switch the first allocation to alloc_file_pseudo()Al Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12anon_inode_getfile(): switch to alloc_file_pseudo()Al Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12hugetlb_file_setup(): switch to alloc_file_pseudo()Al Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12new wrapper: alloc_file_pseudo()Al Viro
takes inode, vfsmount, name, O_... flags and file_operations and either returns a new struct file (in which case inode reference we held is consumed) or returns ERR_PTR(), in which case no refcounts are altered. converted aio_private_file() and sock_alloc_file() to it Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12switch atomic_open() and lookup_open() to returning 0 in all success casesAl Viro
caller can tell "opened" from "open it yourself" by looking at ->f_mode. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12->atomic_open(): return 0 in all success casesAl Viro
FMODE_OPENED can be used to distingusish "successful open" from the "called finish_no_open(), do it yourself" cases. Since finish_no_open() has been adjusted, no changes in the instances were actually needed. The caller has been adjusted. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12get rid of 'opened' in path_openat() and the helpers downstreamAl Viro
unused now Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12get rid of 'opened' argument of ->atomic_open() - part 3Al Viro
now it can be done... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12getting rid of 'opened' argument of ->atomic_open() - part 2Al Viro
__gfs2_lookup(), gfs2_create_inode(), nfs_finish_open() and fuse_create_open() don't need 'opened' anymore. Get rid of that argument in those. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12getting rid of 'opened' argument of ->atomic_open() - part 1Al Viro
'opened' argument of finish_open() is unused. Kill it. Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
2018-07-12IMA: don't propagate opened through the entire thingAl Viro
just check ->f_mode in ima_appraise_measurement() Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12introduce FMODE_CREATED and switch to itAl Viro
Parallel to FILE_CREATED, goes into ->f_mode instead of *opened. NFS is a bit of a wart here - it doesn't have file at the point where FILE_CREATED used to be set, so we need to propagate it there (for now). IMA is another one (here and everywhere)... Note that this needs do_dentry_open() to leave old bits in ->f_mode alone - we want it to preserve FMODE_CREATED if it had been already set (no other bit can be there). Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12switch all remaining checks for FILE_OPENED to FMODE_OPENEDAl Viro
... and don't bother with setting FILE_OPENED at all. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12now we can fold open_check_o_direct() into do_dentry_open()Al Viro
These checks are better off in do_dentry_open(); the reason we couldn't put them there used to be that callers couldn't tell what kind of cleanup would do_dentry_open() failure call for. Now that we have FMODE_OPENED, cleanup is the same in all cases - it's simply fput(). So let's fold that into do_dentry_open(), as Christoph's patch tried to. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12lift fput() on late failures into path_openat()Al Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12fold put_filp() into fput()Al Viro
Just check FMODE_OPENED in __fput() and be done with that... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12introduce FMODE_OPENEDAl Viro
basically, "is that instance set up enough for regular fput(), or do we want put_filp() for that one". NOTE: the only alloc_file() caller that could be followed by put_filp() is in arch/ia64/kernel/perfmon.c, which is (Kconfig-level) broken. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12security_file_open(): lose cred argumentAl Viro
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12get rid of cred argument of vfs_open() and do_dentry_open()Al Viro
always equal to ->f_cred Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12pass ->f_flags value to alloc_empty_file()Al Viro
... and have it set the f_flags-derived part of ->f_mode. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12pass creds to get_empty_filp(), make sure dentry_open() passes the right credsAl Viro
... and rename get_empty_filp() to alloc_empty_file(). dentry_open() gets creds as argument, but the only thing that sees those is security_file_open() - file->f_cred still ends up with current_cred(). For almost all callers it's the same thing, but there are several broken cases. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12alloc_file(): switch to passing O_... flags instead of FMODE_... modeAl Viro
... so that it could set both ->f_flags and ->f_mode, without callers having to set ->f_flags manually. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12kernel: add kcompat_sys_{f,}statfs64()Mark Rutland
Using this helper allows us to avoid the in-kernel calls to the compat_sys_{f,}statfs64() sycalls, as are necessary for parameter mangling in arm64's compat handling. Following the example of ksys_* functions, kcompat_sys_* functions are intended to be a drop-in replacement for their compat_sys_* counterparts, with the same calling convention. This is necessary to enable conversion of arm64's syscall handling to use pt_regs wrappers. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-11xfs: Initialize variables in xfs_alloc_get_rec before using themCarlos Maiolino
Make sure we initialize *bno and *len, before jumping to out_bad_rec label, and risk calling xfs_warn() with uninitialized variables. Coverity: 100898 Coverity: 1437081 Coverity: 1437129 Coverity: 1437191 Coverity: 1437201 Coverity: 1437212 Coverity: 1437341 Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: remove unused iolock arg from xfs_break_dax_layoutsEric Sandeen
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: kill __xfs_buf_submit_common()Brian Foster
Now that there is only one caller, fold the common submission helper into __xfs_buf_submit(). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: combine [a]sync buffer submission apisBrian Foster
The buffer I/O submission path consists of separate function calls per type. The buffer I/O type is already controlled via buffer state (XBF_ASYNC), however, so there is no real need for separate submission functions. Combine the buffer submission functions into a single function that processes the buffer appropriately based on XBF_ASYNC. Retain an internal helper with a conditional wait parameter to continue to support batched !XBF_ASYNC submission/completion required by delwri queues. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: use sync buffer I/O for sync delwri queue submissionBrian Foster
If a delwri queue occurs of a buffer that sits on a delwri queue wait list, the queue sets _XBF_DELWRI_Q without changing the state of ->b_list. This occurs, for example, if another thread beats the current delwri waiter thread to the buffer lock after I/O completion. Once the waiter acquires the lock, it removes the buffer from the wait list and leaves a buffer with _XBF_DELWRI_Q set but not populated on a list. This results in a lost buffer submission and in turn can result in assert failures due to _XBF_DELWRI_Q being set on buffer reclaim or filesystem lockups if the buffer happens to cover an item in the AIL. This problem has been reproduced by repeated iterations of xfs/305 on high CPU count (28xcpu) systems with limited memory (~1GB). Dirty dquot reclaim races with an xfsaild push of a separate dquot backed by the same buffer such that the buffer sits on the reclaim wait list at the time xfsaild attempts to queue it. Since the latter dquot has been flush locked but the underlying buffer not submitted for I/O, the dquot pins the AIL and causes the filesystem to livelock. This race is essentially made possible by the buffer lock cycle involved with waiting on a synchronous delwri queue submission. Close the race by using synchronous buffer I/O for respective delwri queue submission. This means the buffer remains locked across the I/O and so is inaccessible from other contexts while in the intermediate wait list state. The sync buffer I/O wait mechanism is factored into a helper such that sync delwri buffer submission and serialization are batched operations. Designed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: refactor buffer submission into a common helperBrian Foster
Sync and async buffer submission both do generally similar things with a couple odd exceptions. Refactor the core buffer submission code into a common helper to isolate buffer submission from completion handling of synchronous buffer I/O. This patch does not change behavior. It is a step towards support for using synchronous buffer I/O via synchronous delwri queue submission. Designed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: remove xfs_defer_init() firstblock paramBrian Foster
All but one caller of xfs_defer_init() passes in the ->t_firstblock of the associated transaction. The one outlier is xlog_recover_process_intents(), which simply passes a dummy value because a valid pointer is required. This firstblock variable can simply be removed. At this point we could remove the xfs_defer_init() firstblock parameter and initialize ->t_firstblock directly. Even that is not necessary, however, because ->t_firstblock is automatically reinitialized in the new transaction on a transaction roll. Since xfs_defer_init() should never occur more than once on a particular transaction (since the corresponding finish will roll it), replace the reinit from xfs_defer_init() with an assert that verifies the transaction has a NULLFSBLOCK firstblock. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>