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* xfs: Remove duplicate jumps to the same labelJan Kara2015-07-291-8/+2
| | | | | | | | | | | xfs_create() and xfs_create_tmpfile() have useless jumps to identical labels. Simplify them. Signed-off-by: Jan Kara <jack@suse.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: Use consistent logging message prefixesJoe Perches2015-07-295-37/+43
| | | | | | | | | | | | | | The second and subsequent lines of multi-line logging messages are not prefixed with the same information as the first line. Separate messages with newlines into multiple calls to ensure consistent prefixing and allow easier grep use. Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: validate transaction header length on log recoveryBrian Foster2015-07-291-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | When log recovery hits a new transaction, it copies the transaction header from the expected location in the log to the in-core structure using the length from the op record header. This length is validated to ensure it doesn't exceed the length of the record, but not against the expected size of a transaction header (and thus the size of the in-core structure). If the on-disk length is corrupted, the associated memcpy() can overflow, write to unrelated memory and lead to crashes. This has been reproduced via filesystem fuzzing. The code currently handles the possibility that the transaction header is split across two op records. Neither instance accounts for corruption where the op record length might be larger than the in-core transaction header. Update both sites to detect such corruption, warn and return an error from log recovery. Also add some comments and assert that if the record is split, the copy of the second portion is less than a full header. Otherwise, this suggests the copy of the second portion could have overwritten bits from the first and thus that something could be wrong. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: close xc_cil list_empty() races with cil commit sequenceBrian Foster2015-07-291-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have seen somewhat rare reports of the following assert from xlog_cil_push_background() failing during ltp tests or somewhat innocuous desktop root fs workloads (e.g., virt operations, initramfs construction): ASSERT(!list_empty(&cil->xc_cil)); The reasoning behind the assert is that the transaction has inserted items to the CIL and hit background push codepath all with cil->xc_ctx_lock held for reading. This locks out background commit from emptying the CIL, which acquires the lock for writing. Therefore, the reasoning is that the items previously inserted in the CIL should still be present. The cil->xc_ctx_lock read lock is not sufficient to protect the xc_cil list, however, due to how CIL insertion is handled. xlog_cil_insert_items() inserts and reorders the dirty transaction items to the tail of the CIL under xc_cil_lock. It uses list_move_tail() to achieve insertion and reordering in the same block of code. This function removes and reinserts an item to the tail of the list. If a transaction commits an item that was already logged and thus already resides in the CIL, and said item is the sole item on the list, the removal and reinsertion creates a temporary state where the list is actually empty. This state is not valid and thus should never be observed by concurrent transaction commit-side checks in the circumstances outlined above. We do not want to acquire the xc_cil_lock in all of these instances as it was previously removed and replaced with a separate push lock for performance reasons. Therefore, close any races with list_empty() on the insertion side by ensuring that the list is never in a transient empty state. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: xfs_bunmapi() does not need XFS_BMAPI_METADATA flagDave Chinner2015-07-294-24/+20
| | | | | | | | | | | xfs_bunmapi() doesn't care what type of extent is being freed and does not look at the XFS_BMAPI_METADATA flag at all. As such we can remove the XFS_BMAPI_METADATA from all callers that use it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-07-124-6/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS fixes from Al Viro: "Fixes for this cycle regression in overlayfs and a couple of long-standing (== all the way back to 2.6.12, at least) bugs" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: freeing unlinked file indefinitely delayed fix a braino in ovl_d_select_inode() 9p: don't leave a half-initialized inode sitting around
| * freeing unlinked file indefinitely delayedAl Viro2015-07-121-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally opening a file, unlinking it and then closing will have the inode freed upon close() (provided that it's not otherwise busy and has no remaining links, of course). However, there's one case where that does *not* happen. Namely, if you open it by fhandle with cold dcache, then unlink() and close(). In normal case you get d_delete() in unlink(2) notice that dentry is busy and unhash it; on the final dput() it will be forcibly evicted from dcache, triggering iput() and inode removal. In this case, though, we end up with *two* dentries - disconnected (created by open-by-fhandle) and regular one (used by unlink()). The latter will have its reference to inode dropped just fine, but the former will not - it's considered hashed (it is on the ->s_anon list), so it will stay around until the memory pressure will finally do it in. As the result, we have the final iput() delayed indefinitely. It's trivial to reproduce - void flush_dcache(void) { system("mount -o remount,rw /"); } static char buf[20 * 1024 * 1024]; main() { int fd; union { struct file_handle f; char buf[MAX_HANDLE_SZ]; } x; int m; x.f.handle_bytes = sizeof(x); chdir("/root"); mkdir("foo", 0700); fd = open("foo/bar", O_CREAT | O_RDWR, 0600); close(fd); name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0); flush_dcache(); fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR); unlink("foo/bar"); write(fd, buf, sizeof(buf)); system("df ."); /* 20Mb eaten */ close(fd); system("df ."); /* should've freed those 20Mb */ flush_dcache(); system("df ."); /* should be the same as #2 */ } will spit out something like Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 322023 303843 1131 100% / Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 322023 303843 1131 100% / Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 322023 283282 21692 93% / - inode gets freed only when dentry is finally evicted (here we trigger than by remount; normally it would've happened in response to memory pressure hell knows when). Cc: stable@vger.kernel.org # v2.6.38+; earlier ones need s/kill_it/unhash_it/ Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fix a braino in ovl_d_select_inode()Al Viro2015-07-121-0/+3
| | | | | | | | | | | | | | | | | | when opening a directory we want the overlayfs inode, not one from the topmost layer. Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com> Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * 9p: don't leave a half-initialized inode sitting aroundAl Viro2015-07-122-4/+2
| | | | | | | | | | Cc: stable@vger.kernel.org # all branches Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus-4.2' of ↵Linus Torvalds2015-07-1113-124/+641
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "This is an assortment of fixes. Most of the commits are from Filipe (fsync, the inode allocation cache and a few others). Mark kicked in a series fixing corners in the extent sharing ioctls, and everyone else fixed up on assorted other problems" * 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix wrong check for btrfs_force_chunk_alloc() Btrfs: fix warning of bytes_may_use Btrfs: fix hang when failing to submit bio of directIO Btrfs: fix a comment in inode.c:evict_inode_truncate_pages() Btrfs: fix memory corruption on failure to submit bio for direct IO btrfs: don't update mtime/ctime on deduped inodes btrfs: allow dedupe of same inode btrfs: fix deadlock with extent-same and readpage btrfs: pass unaligned length to btrfs_cmp_data() Btrfs: fix fsync after truncate when no_holes feature is enabled Btrfs: fix fsync xattr loss in the fast fsync path Btrfs: fix fsync data loss after append write Btrfs: fix crash on close_ctree() if cleaner starts new transaction Btrfs: fix race between caching kthread and returning inode to inode cache Btrfs: use kmem_cache_free when freeing entry in inode cache Btrfs: fix race between balance and unused block group deletion btrfs: add error handling for scrub_workers_get() btrfs: cleanup noused initialization of dev in btrfs_end_bio() btrfs: qgroup: allow user to clear the limitation on qgroup
| * | Btrfs: fix wrong check for btrfs_force_chunk_alloc()Shilong Wang2015-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | btrfs_force_chunk_alloc() return 1 for allocation chunk successfully. This problem exists since commit c87f08ca4. With this patch, we might fix some enospc problems for balances. Signed-off-by: Wang Shilong <wangshilong1991@gmail.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix warning of bytes_may_useLiu Bo2015-07-012-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running generic/019, dmesg got several warnings from btrfs_free_reserved_data_space(). Test generic/019 produces some disk failures so sumbit dio will get errors, in which case, btrfs_direct_IO() goes to the error handling and free bytes_may_use, but the problem is that bytes_may_use has been free'd during get_block(). This adds a runtime flag to show if we've gone through get_block(), if so, don't do the cleanup work. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix hang when failing to submit bio of directIOLiu Bo2015-07-011-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hang is uncoverd by generic/019. btrfs_endio_direct_write() skips the "finish_ordered_fn" part when it hits an error, thus those added ordered extents will never get processed, which block processes that waiting for them via btrfs_start_ordered_extent(). This fixes the above, and meanwhile finish_ordered_fn will do the space accounting work. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix a comment in inode.c:evict_inode_truncate_pages()Filipe Manana2015-07-011-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment was not correct about the part where it says the endio callback of the bio might have not yet been called - update it to mention that by that time the endio callback execution might still be in progress only. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix memory corruption on failure to submit bio for direct IOFilipe Manana2015-07-012-18/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we fail to submit a bio for a direct IO request, we were grabbing the corresponding ordered extent and decrementing its reference count twice, once for our lookup reference and once for the ordered tree reference. This was a problem because it caused the ordered extent to be freed without removing it from the ordered tree and any lists it might be attached to, leaving dangling pointers to the ordered extent around. Example trace with CONFIG_DEBUG_PAGEALLOC=y: [161779.858707] BUG: unable to handle kernel paging request at 0000000087654330 [161779.859983] IP: [<ffffffff8124ca68>] rb_prev+0x22/0x3b [161779.860636] PGD 34d818067 PUD 0 [161779.860636] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [161779.860636] Call Trace: [161779.860636] [<ffffffffa06b36a6>] __tree_search+0xd9/0xf9 [btrfs] [161779.860636] [<ffffffffa06b3708>] tree_search+0x42/0x63 [btrfs] [161779.860636] [<ffffffffa06b4868>] ? btrfs_lookup_ordered_range+0x2d/0xa5 [btrfs] [161779.860636] [<ffffffffa06b4873>] btrfs_lookup_ordered_range+0x38/0xa5 [btrfs] [161779.860636] [<ffffffffa06aab8e>] btrfs_get_blocks_direct+0x11b/0x615 [btrfs] [161779.860636] [<ffffffff8119727f>] do_blockdev_direct_IO+0x5ff/0xb43 [161779.860636] [<ffffffffa06aaa73>] ? btrfs_page_exists_in_range+0x1ad/0x1ad [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffffa06a10ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [161779.860636] [<ffffffffa06affaa>] ? btrfs_file_write_iter+0x15f/0x3e0 [btrfs] [161779.860636] [<ffffffffa06b004c>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] (...) We were also not freeing the btrfs_dio_private we allocated previously, which kmemleak reported with the following trace in its sysfs file: unreferenced object 0xffff8803f553bf80 (size 96): comm "xfs_io", pid 4501, jiffies 4295039588 (age 173.936s) hex dump (first 32 bytes): 88 6c 9b f5 02 88 ff ff 00 00 00 00 00 00 00 00 .l.............. 00 00 00 00 00 00 00 00 00 00 c4 00 00 00 00 00 ................ backtrace: [<ffffffff81161ffe>] create_object+0x172/0x29a [<ffffffff8145870f>] kmemleak_alloc+0x25/0x41 [<ffffffff81154e64>] kmemleak_alloc_recursive.constprop.40+0x16/0x18 [<ffffffff811579ed>] kmem_cache_alloc_trace+0xfb/0x148 [<ffffffffa03d8cff>] btrfs_submit_direct+0x65/0x16a [btrfs] [<ffffffff811968dc>] dio_bio_submit+0x62/0x8f [<ffffffff811975fe>] do_blockdev_direct_IO+0x97e/0xb43 [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [<ffffffffa03d70ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [<ffffffffa03e604d>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] [<ffffffff8116586a>] __vfs_write+0x7c/0xa5 [<ffffffff81165da9>] vfs_write+0xa0/0xe4 [<ffffffff81166675>] SyS_pwrite64+0x64/0x82 [<ffffffff81464fd7>] system_call_fastpath+0x12/0x6f [<ffffffffffffffff>] 0xffffffffffffffff For read requests we weren't doing any cleanup either (none of the work done by btrfs_endio_direct_read()), so a failure submitting a bio for a read request would leave a range in the inode's io_tree locked forever, blocking any future operations (both reads and writes) against that range. So fix this by making sure we do the same cleanup that we do for the case where the bio submission succeeds. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: don't update mtime/ctime on deduped inodesMark Fasheh2015-07-011-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One issue users have reported is that dedupe changes mtime on files, resulting in tools like rsync thinking that their contents have changed when in fact the data is exactly the same. We also skip the ctime update as no user-visible metadata changes here and we want dedupe to be transparent to the user. Clone still wants time changes, so we special case this in the code. This was tested with the btrfs-extent-same tool. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: allow dedupe of same inodeMark Fasheh2015-07-011-16/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clone() supports cloning within an inode so extent-same can do the same now. This patch fixes up the locking in extent-same to know about the single-inode case. In addition to that, we add a check for overlapping ranges, which clone does not allow. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: fix deadlock with extent-same and readpageMark Fasheh2015-07-011-31/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->readpage() does page_lock() before extent_lock(), we do the opposite in extent-same. We want to reverse the order in btrfs_extent_same() but it's not quite straightforward since the page locks are taken inside btrfs_cmp_data(). So I split btrfs_cmp_data() into 3 parts with a small context structure that is passed between them. The first, btrfs_cmp_data_prepare() gathers up the pages needed (taking page lock as required) and puts them on our context structure. At this point, we are safe to lock the extent range. Afterwards, we use btrfs_cmp_data() to do the data compare as usual and btrfs_cmp_data_free() to clean up our context. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: pass unaligned length to btrfs_cmp_data()Mark Fasheh2015-07-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the case that we dedupe the tail of a file, we might expand the dedupe len out to the end of our last block. We don't want to compare data past i_size however, so pass the original length to btrfs_cmp_data(). Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix fsync after truncate when no_holes feature is enabledFilipe Manana2015-07-011-0/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix fsync xattr loss in the fast fsync pathFilipe Manana2015-06-301-0/+104
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix fsync data loss after append writeFilipe Manana2015-06-301-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we do an append write to a file (which increases its inode's i_size) that does not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, and the previous transaction added a new hard link to the file, which sets the flag BTRFS_INODE_COPY_EVERYTHING in the file's inode, and then fsync the file, the inode's new i_size isn't logged. This has the consequence that after the fsync log is replayed, the file size remains what it was before the append write operation, which means users/applications will not be able to read the data that was successsfully fsync'ed before. This happens because neither the inode item nor the delayed inode get their i_size updated when the append write is made - doing so would require starting a transaction in the buffered write path, something that we do not do intentionally for performance reasons. Fix this by making sure that when the flag BTRFS_INODE_COPY_EVERYTHING is set the inode is logged with its current i_size (log the in-memory inode into the log tree). This issue is not a recent regression and is easy to reproduce with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs generic _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and then fsync it. # The fsync here is only needed to trigger the issue in btrfs, as it causes the # the flag BTRFS_INODE_NEEDS_FULL_SYNC to be removed from the btrfs inode. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io sync # Add a hard link to our file. # On btrfs this sets the flag BTRFS_INODE_COPY_EVERYTHING on the btrfs inode, # which is a necessary condition to trigger the issue. ln $SCRATCH_MNT/foo $SCRATCH_MNT/bar # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now append more data to our file, increasing its size, and fsync the file. # In btrfs because the inode flag BTRFS_INODE_COPY_EVERYTHING was set and the # write path did not update the inode item in the btree nor the delayed inode # item (in memory struture) in the current transaction (created by the fsync # handler), the fsync did not record the inode's new i_size in the fsync # log/journal. This made the data unavailable after the fsync log/journal is # replayed. $XFS_IO_PROG -c "pwrite -S 0xbb 32K 32K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io echo "File content after fsync and before crash:" od -t x1 $SCRATCH_MNT/foo _crash_and_mount echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected file output before and after the crash/power failure expects the appended data to be available, which is: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0100000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0200000 Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix crash on close_ctree() if cleaner starts new transactionFilipe Manana2015-06-301-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Often when running fstests btrfs/079 I was running into the following trace during umount on one of my qemu/kvm test vms: [ 8245.682441] WARNING: CPU: 8 PID: 25064 at fs/btrfs/extent-tree.c:138 btrfs_put_block_group+0x51/0x69 [btrfs]() [ 8245.685039] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 acpi_cpufreq processor psmouse i2c_core thermal_sys parport evdev serio_raw button pcspkr microcode ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata floppy virtio_pci virtio_ring scsi_mod virtio e1000 [last unloaded: btrfs] [ 8245.693860] CPU: 8 PID: 25064 Comm: umount Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [ 8245.695081] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [ 8245.697583] 0000000000000009 ffff88020d047ce8 ffffffff8145eec7 ffffffff81095dce [ 8245.699234] 0000000000000000 ffff88020d047d28 ffffffff8104b399 0000000000000028 [ 8245.700995] ffffffffa04db07b ffff8801c6036c00 ffff8801c6036d68 ffff880202eb40b0 [ 8245.702510] Call Trace: [ 8245.703006] [<ffffffff8145eec7>] dump_stack+0x4f/0x7b [ 8245.705393] [<ffffffff81095dce>] ? console_unlock+0x356/0x3a2 [ 8245.706569] [<ffffffff8104b399>] warn_slowpath_common+0xa1/0xbb [ 8245.707747] [<ffffffffa04db07b>] ? btrfs_put_block_group+0x51/0x69 [btrfs] [ 8245.709101] [<ffffffff8104b456>] warn_slowpath_null+0x1a/0x1c [ 8245.710274] [<ffffffffa04db07b>] btrfs_put_block_group+0x51/0x69 [btrfs] [ 8245.711823] [<ffffffffa04e3473>] btrfs_free_block_groups+0x145/0x322 [btrfs] [ 8245.713251] [<ffffffffa04ef31a>] close_ctree+0x1ef/0x325 [btrfs] [ 8245.714448] [<ffffffff8117d26e>] ? evict_inodes+0xdc/0xeb [ 8245.715539] [<ffffffffa04cb3ad>] btrfs_put_super+0x19/0x1b [btrfs] [ 8245.716835] [<ffffffff81167607>] generic_shutdown_super+0x73/0xef [ 8245.718015] [<ffffffff81167a3a>] kill_anon_super+0x13/0x1e [ 8245.719101] [<ffffffffa04cb1b6>] btrfs_kill_super+0x17/0x23 [btrfs] [ 8245.720316] [<ffffffff81167544>] deactivate_locked_super+0x3b/0x68 [ 8245.721517] [<ffffffff81167dd6>] deactivate_super+0x3f/0x43 [ 8245.722581] [<ffffffff8117fbb9>] cleanup_mnt+0x59/0x78 [ 8245.723538] [<ffffffff8117fc18>] __cleanup_mnt+0x12/0x14 [ 8245.724572] [<ffffffff81065371>] task_work_run+0x8f/0xbc [ 8245.725598] [<ffffffff810028fb>] do_notify_resume+0x45/0x53 [ 8245.726892] [<ffffffff814651ac>] int_signal+0x12/0x17 [ 8245.737887] ---[ end trace a01d038397e99b92 ]--- [ 8245.769363] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 8245.770737] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 acpi_cpufreq processor psmouse i2c_core thermal_sys parport evdev serio_raw button pcspkr microcode ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata floppy virtio_pci virtio_ring scsi_mod virtio e1000 [last unloaded: btrfs] [ 8245.772641] CPU: 2 PID: 25064 Comm: umount Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [ 8245.772641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [ 8245.772641] task: ffff880013005810 ti: ffff88020d044000 task.ti: ffff88020d044000 [ 8245.772641] RIP: 0010:[<ffffffffa051c8e6>] [<ffffffffa051c8e6>] btrfs_queue_work+0x2c/0x14d [btrfs] [ 8245.772641] RSP: 0018:ffff88020d0478b8 EFLAGS: 00010202 [ 8245.772641] RAX: 0000000000000004 RBX: 6b6b6b6b6b6b6b6b RCX: ffffffffa0581488 [ 8245.772641] RDX: 0000000000000000 RSI: ffff880194b7bf48 RDI: ffff880144b6a7a0 [ 8245.772641] RBP: ffff88020d0478d8 R08: 0000000000000000 R09: 000000000000ffff [ 8245.772641] R10: 0000000000000004 R11: 0000000000000005 R12: ffff880194b7bf48 [ 8245.772641] R13: ffff880194b7bf48 R14: 0000000000000410 R15: 0000000000000000 [ 8245.772641] FS: 00007f991e77d840(0000) GS:ffff88023e280000(0000) knlGS:0000000000000000 [ 8245.772641] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 8245.772641] CR2: 00007fbbd325ee68 CR3: 000000021de8e000 CR4: 00000000000006e0 [ 8245.772641] Stack: [ 8245.772641] ffff880194b7bf00 ffff880202eb4000 ffff880194b7bf48 0000000000000410 [ 8245.772641] ffff88020d047958 ffffffffa04ec6d5 ffff8801629b2ee8 0000000082987570 [ 8245.772641] 0000000000a5813f 0000000000000001 ffff880013006100 0000000000000002 [ 8245.772641] Call Trace: [ 8245.772641] [<ffffffffa04ec6d5>] btrfs_wq_submit_bio+0xe1/0x17b [btrfs] [ 8245.772641] [<ffffffff81086bff>] ? check_irq_usage+0x76/0x87 [ 8245.772641] [<ffffffffa04ec825>] btree_submit_bio_hook+0xb6/0xd9 [btrfs] [ 8245.772641] [<ffffffffa04ebb7c>] ? btree_csum_one_bio+0xad/0xad [btrfs] [ 8245.772641] [<ffffffffa04eb1a6>] ? btree_io_failed_hook+0x5e/0x5e [btrfs] [ 8245.772641] [<ffffffffa050a6e7>] submit_one_bio+0x8c/0xc7 [btrfs] [ 8245.772641] [<ffffffffa050d75b>] submit_extent_page.isra.18+0x9d/0x186 [btrfs] [ 8245.772641] [<ffffffffa050d95b>] write_one_eb+0x117/0x1ae [btrfs] [ 8245.772641] [<ffffffffa050a79b>] ? end_extent_buffer_writeback+0x21/0x21 [btrfs] [ 8245.772641] [<ffffffffa0510510>] btree_write_cache_pages+0x2ab/0x385 [btrfs] [ 8245.772641] [<ffffffffa04eb2b8>] btree_writepages+0x23/0x5c [btrfs] [ 8245.772641] [<ffffffff8111c661>] do_writepages+0x23/0x2c [ 8245.772641] [<ffffffff81189cd4>] __writeback_single_inode+0xda/0x5bd [ 8245.772641] [<ffffffff8118aa60>] ? writeback_single_inode+0x2b/0x173 [ 8245.772641] [<ffffffff8118aafd>] writeback_single_inode+0xc8/0x173 [ 8245.772641] [<ffffffff8118ac95>] write_inode_now+0x8a/0x95 [ 8245.772641] [<ffffffff81247bf0>] ? _atomic_dec_and_lock+0x30/0x4e [ 8245.772641] [<ffffffff8117cc5e>] iput+0x17d/0x26a [ 8245.772641] [<ffffffffa04ef355>] close_ctree+0x22a/0x325 [btrfs] [ 8245.772641] [<ffffffff8117d26e>] ? evict_inodes+0xdc/0xeb [ 8245.772641] [<ffffffffa04cb3ad>] btrfs_put_super+0x19/0x1b [btrfs] [ 8245.772641] [<ffffffff81167607>] generic_shutdown_super+0x73/0xef [ 8245.772641] [<ffffffff81167a3a>] kill_anon_super+0x13/0x1e [ 8245.772641] [<ffffffffa04cb1b6>] btrfs_kill_super+0x17/0x23 [btrfs] [ 8245.772641] [<ffffffff81167544>] deactivate_locked_super+0x3b/0x68 [ 8245.772641] [<ffffffff81167dd6>] deactivate_super+0x3f/0x43 [ 8245.772641] [<ffffffff8117fbb9>] cleanup_mnt+0x59/0x78 [ 8245.772641] [<ffffffff8117fc18>] __cleanup_mnt+0x12/0x14 [ 8245.772641] [<ffffffff81065371>] task_work_run+0x8f/0xbc [ 8245.772641] [<ffffffff810028fb>] do_notify_resume+0x45/0x53 [ 8245.772641] [<ffffffff814651ac>] int_signal+0x12/0x17 [ 8245.772641] Code: 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 89 f4 48 8b 46 70 a8 04 74 09 48 8b 5f 08 48 85 db 75 03 48 8b 1f 49 89 5c 24 68 <83> 7b 5c ff 74 04 f0 ff 43 50 49 83 7c 24 08 00 74 2c 4c 8d 6b [ 8245.772641] RIP [<ffffffffa051c8e6>] btrfs_queue_work+0x2c/0x14d [btrfs] [ 8245.772641] RSP <ffff88020d0478b8> [ 8245.845040] ---[ end trace a01d038397e99b93 ]--- For logical reasons such as the phase of the moon, this happened more often with "-o inode_cache" than without any mount options. After some debugging it turned out to be simple to understand what was happening: 1) close_ctree() is called; 2) It then stops the transaction kthread, which commits the current transaction; 3) It asks the cleaner kthread to stop, which is currently running btrfs_delete_unused_bgs(); 4) btrfs_delete_unused_bgs() finds an unused block group, starts a new transaction, deletes the block group, which implies COWing some tree nodes and leafs and dirtying their respective pages, and then finally it ends the transaction it started, without committing it; 5) The cleaner kthread stops; 6) close_ctree() releases (from memory) the block group objects, which produces the warning in the trace pasted above; 7) Then it invalidates all pages of the btree inode, by calling invalidate_inode_pages2(), which waits for any pages under writeback, and releases any non-dirty pages; 8) All work queues are destroyed (waiting first for their current tasks to finish execution); 9) A final iput() is called against the btree inode; 10) This iput triggers a writeback of the btree inode because it still has dirty pages; 11) This starts the whole chain of callbacks for the btree inode until it eventually reaches btrfs_wq_submit_bio() where it leads to a NULL pointer dereference because the work queues were already destroyed. Fix this by making the cleaner commit any transaction that it started after the transaction kthread was stopped. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix race between caching kthread and returning inode to inode cacheFilipe Manana2015-06-301-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While the inode cache caching kthread is calling btrfs_unpin_free_ino(), we could have a concurrent call to btrfs_return_ino() that adds a new entry to the root's free space cache of pinned inodes. This concurrent call does not acquire the fs_info->commit_root_sem before adding a new entry if the caching state is BTRFS_CACHE_FINISHED, which is a problem because the caching kthread calls btrfs_unpin_free_ino() after setting the caching state to BTRFS_CACHE_FINISHED and therefore races with the task calling btrfs_return_ino(), which is adding a new entry, while the former (caching kthread) is navigating the cache's rbtree, removing and freeing nodes from the cache's rbtree without acquiring the spinlock that protects the rbtree. This race resulted in memory corruption due to double free of struct btrfs_free_space objects because both tasks can end up doing freeing the same objects. Note that adding a new entry can result in merging it with other entries in the cache, in which case those entries are freed. This is particularly important as btrfs_free_space structures are also used for the block group free space caches. This memory corruption can be detected by a debugging kernel, which reports it with the following trace: [132408.501148] slab error in verify_redzone_free(): cache `btrfs_free_space': double free detected [132408.505075] CPU: 15 PID: 12248 Comm: btrfs-ino-cache Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [132408.505075] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [132408.505075] ffff880023e7d320 ffff880163d73cd8 ffffffff8145eec7 ffffffff81095dce [132408.505075] ffff880009735d40 ffff880163d73ce8 ffffffff81154e1e ffff880163d73d68 [132408.505075] ffffffff81155733 ffffffffa054a95a ffff8801b6099f00 ffffffffa0505b5f [132408.505075] Call Trace: [132408.505075] [<ffffffff8145eec7>] dump_stack+0x4f/0x7b [132408.505075] [<ffffffff81095dce>] ? console_unlock+0x356/0x3a2 [132408.505075] [<ffffffff81154e1e>] __slab_error.isra.28+0x25/0x36 [132408.505075] [<ffffffff81155733>] __cache_free+0xe2/0x4b6 [132408.505075] [<ffffffffa054a95a>] ? __btrfs_add_free_space+0x2f0/0x343 [btrfs] [132408.505075] [<ffffffffa0505b5f>] ? btrfs_unpin_free_ino+0x8e/0x99 [btrfs] [132408.505075] [<ffffffff810f3b30>] ? time_hardirqs_off+0x15/0x28 [132408.505075] [<ffffffff81084d42>] ? trace_hardirqs_off+0xd/0xf [132408.505075] [<ffffffff811563a1>] ? kfree+0xb6/0x14e [132408.505075] [<ffffffff811563d0>] kfree+0xe5/0x14e [132408.505075] [<ffffffffa0505b5f>] btrfs_unpin_free_ino+0x8e/0x99 [btrfs] [132408.505075] [<ffffffffa0505e08>] caching_kthread+0x29e/0x2d9 [btrfs] [132408.505075] [<ffffffffa0505b6a>] ? btrfs_unpin_free_ino+0x99/0x99 [btrfs] [132408.505075] [<ffffffff8106698f>] kthread+0xef/0xf7 [132408.505075] [<ffffffff810f3b08>] ? time_hardirqs_on+0x15/0x28 [132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad [132408.505075] [<ffffffff814653d2>] ret_from_fork+0x42/0x70 [132408.505075] [<ffffffff810668a0>] ? __kthread_parkme+0xad/0xad [132408.505075] ffff880023e7d320: redzone 1:0x9f911029d74e35b, redzone 2:0x9f911029d74e35b. [132409.501654] slab: double free detected in cache 'btrfs_free_space', objp ffff880023e7d320 [132409.503355] ------------[ cut here ]------------ [132409.504241] kernel BUG at mm/slab.c:2571! Therefore fix this by having btrfs_unpin_free_ino() acquire the lock that protects the rbtree while doing the searches and removing entries. Fixes: 1c70d8fb4dfa ("Btrfs: fix inode caching vs tree log") Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: use kmem_cache_free when freeing entry in inode cacheFilipe Manana2015-06-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The free space entries are allocated using kmem_cache_zalloc(), through __btrfs_add_free_space(), therefore we should use kmem_cache_free() and not kfree() to avoid any confusion and any potential problem. Looking at the kfree() definition at mm/slab.c it has the following comment: /* * (...) * * Don't free memory not originally allocated by kmalloc() * or you will run into trouble. */ So better be safe and use kmem_cache_free(). Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | Btrfs: fix race between balance and unused block group deletionFilipe Manana2015-06-304-6/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a race between deleting an unused block group and balancing the same block group that leads to an assertion failure/BUG(), producing the following trace: [181631.208236] BTRFS: assertion failed: 0, file: fs/btrfs/volumes.c, line: 2622 [181631.220591] ------------[ cut here ]------------ [181631.222959] kernel BUG at fs/btrfs/ctree.h:4062! [181631.223932] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [181631.224566] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse acpi_cpufreq parpor$ [181631.224566] CPU: 8 PID: 17451 Comm: btrfs Tainted: G W 4.1.0-rc5-btrfs-next-10+ #1 [181631.224566] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [181631.224566] task: ffff880127e09590 ti: ffff8800b5824000 task.ti: ffff8800b5824000 [181631.224566] RIP: 0010:[<ffffffffa03f19f6>] [<ffffffffa03f19f6>] assfail.constprop.50+0x1e/0x20 [btrfs] [181631.224566] RSP: 0018:ffff8800b5827ae8 EFLAGS: 00010246 [181631.224566] RAX: 0000000000000040 RBX: ffff8800109fc218 RCX: ffffffff81095dce [181631.224566] RDX: 0000000000005124 RSI: ffffffff81464819 RDI: 00000000ffffffff [181631.224566] RBP: ffff8800b5827ae8 R08: 0000000000000001 R09: 0000000000000000 [181631.224566] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800109fc200 [181631.224566] R13: ffff880020095000 R14: ffff8800b1a13f38 R15: ffff880020095000 [181631.224566] FS: 00007f70ca0b0c80(0000) GS:ffff88013ec00000(0000) knlGS:0000000000000000 [181631.224566] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [181631.224566] CR2: 00007f2872ab6e68 CR3: 00000000a717c000 CR4: 00000000000006e0 [181631.224566] Stack: [181631.224566] ffff8800b5827ba8 ffffffffa03f3916 ffff8800b5827b38 ffffffffa03d080e [181631.224566] ffffffffa03d1423 ffff880020095000 ffff88001233c000 0000000000000001 [181631.224566] ffff880020095000 ffff8800b1a13f38 0000000a69c00000 0000000000000000 [181631.224566] Call Trace: [181631.224566] [<ffffffffa03f3916>] btrfs_remove_chunk+0xa4/0x6bb [btrfs] [181631.224566] [<ffffffffa03d080e>] ? join_transaction.isra.8+0xb9/0x3ba [btrfs] [181631.224566] [<ffffffffa03d1423>] ? wait_current_trans.isra.13+0x22/0xfc [btrfs] [181631.224566] [<ffffffffa03f3fbc>] btrfs_relocate_chunk.isra.29+0x8f/0xa7 [btrfs] [181631.224566] [<ffffffffa03f54df>] btrfs_balance+0xaa4/0xc52 [btrfs] [181631.224566] [<ffffffffa03fd388>] btrfs_ioctl_balance+0x23f/0x2b0 [btrfs] [181631.224566] [<ffffffff810872f9>] ? trace_hardirqs_on+0xd/0xf [181631.224566] [<ffffffffa04019a3>] btrfs_ioctl+0xfe2/0x2220 [btrfs] [181631.224566] [<ffffffff812603ed>] ? __this_cpu_preempt_check+0x13/0x15 [181631.224566] [<ffffffff81084669>] ? arch_local_irq_save+0x9/0xc [181631.224566] [<ffffffff81138def>] ? handle_mm_fault+0x834/0xcd2 [181631.224566] [<ffffffff81138def>] ? handle_mm_fault+0x834/0xcd2 [181631.224566] [<ffffffff8103e48c>] ? __do_page_fault+0x211/0x424 [181631.224566] [<ffffffff811755e6>] do_vfs_ioctl+0x3c6/0x479 (...) The sequence of steps leading to this are: CPU 0 CPU 1 btrfs_balance() btrfs_relocate_chunk() btrfs_relocate_block_group(bg X) btrfs_lookup_block_group(bg X) cleaner_kthread locks fs_info->cleaner_mutex btrfs_delete_unused_bgs() finds bg X, which became unused in the previous transaction checks bg X ->ro == 0, so it proceeds sets bg X ->ro to 1 (btrfs_set_block_group_ro(bg X)) blocks on fs_info->cleaner_mutex btrfs_remove_chunk(bg X) unlocks fs_info->cleaner_mutex acquires fs_info->cleaner_mutex relocate_block_group() --> does nothing, no extents found in the extent tree from bg X unlocks fs_info->cleaner_mutex btrfs_relocate_block_group(bg X) returns btrfs_remove_chunk(bg X) extent map not found --> ASSERT(0) Fix this by using a new mutex to make sure these 2 operations, block group relocation and removal, are serialized. This issue is reproducible by running fstests generic/038 (which stresses chunk allocation and automatic removal of unused block groups) together with the following balance loop: while true; do btrfs balance start -dusage=0 <mountpoint> ; done Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: add error handling for scrub_workers_get()Zhao Lei2015-06-301-19/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | Although it is a rare case, we'd better free previous allocated memory on error. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: cleanup noused initialization of dev in btrfs_end_bio()Zhao Lei2015-06-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is introduced by: c404e0dc2c843b154f9a36c3aec10d0a715d88eb Btrfs: fix use-after-free in the finishing procedure of the device replace But seems no relationship with that bug, this patch revirt these code block for cleanup. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | btrfs: qgroup: allow user to clear the limitation on qgroupYang Dongsheng2015-06-301-8/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we can only set a limitation on a qgroup, but we can not clear it. This patch provide a choice to user to clear a limitation on qgroup by passing a value of CLEAR_VALUE(-1) to kernel. Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | | hpfs: hpfs_error: Remove static buffer, use vsprintf extension %pV insteadJoe Perches2015-07-091-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Removing unnecessary static buffers is good. Use the vsprintf %pV extension instead. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Cc: stable@vger.kernel.org # v2.6.36+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | hpfs: kstrdup() out of memory handlingSanidhya Kashyap2015-07-091-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a possibility of nothing being allocated to the new_opts in case of memory pressure, therefore return ENOMEM for such case. Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | hpfs: Remove unessary castFiro Yang2015-07-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid a pointless kmem_cache_alloc() return value cast in fs/hpfs/super.c::hpfs_alloc_inode() Signed-off-by: Firo Yang <firogm@gmail.com> Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | hpfs: add fstrim supportMikulas Patocka2015-07-095-0/+128
| | | | | | | | | | | | | | | | | | | | | This patch adds support for fstrim to the HPFS filesystem. Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | ioctl_compat: handle FITRIMMikulas Patocka2015-07-096-7/+1
| |/ |/| | | | | | | | | | | | | | | | | | | The FITRIM ioctl has the same arguments on 32-bit and 64-bit architectures, so we can add it to the list of compatible ioctls and drop it from compat_ioctl method of various filesystems. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ted Ts'o <tytso@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds2015-07-054-21/+40
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bugfixes from Ted Ts'o: "Bug fixes (all for stable kernels) for ext4: - address corner cases for indirect blocks->extent migration - fix reserved block accounting invalidate_page when page_size != block_size (i.e., ppc or 1k block size file systems) - fix deadlocks when a memcg is under heavy memory pressure - fix fencepost error in lazytime optimization" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: replace open coded nofail allocation in ext4_free_blocks() ext4: correctly migrate a file with a hole at the beginning ext4: be more strict when migrating to non-extent based file ext4: fix reservation release on invalidatepage for delalloc fs ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp bufferhead: Add _gfp version for sb_getblk() ext4: fix fencepost error in lazytime optimization
| * | ext4: replace open coded nofail allocation in ext4_free_blocks()Michal Hocko2015-07-051-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ext4_free_blocks is looping around the allocation request and mimics __GFP_NOFAIL behavior without any allocation fallback strategy. Let's remove the open coded loop and replace it with __GFP_NOFAIL. Without the flag the allocator has no way to find out never-fail requirement and cannot help in any way. Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
| * | ext4: correctly migrate a file with a hole at the beginningEryu Guan2015-07-041-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently ext4_ind_migrate() doesn't correctly handle a file which contains a hole at the beginning of the file. This caused the migration to be done incorrectly, and then if there is a subsequent following delayed allocation write to the "hole", this would reclaim the same data blocks again and results in fs corruption. # assmuing 4k block size ext4, with delalloc enabled # skip the first block and write to the second block xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/ext4/testfile # converting to indirect-mapped file, which would move the data blocks # to the beginning of the file, but extent status cache still marks # that region as a hole chattr -e /mnt/ext4/testfile # delayed allocation writes to the "hole", reclaim the same data block # again, results in i_blocks corruption xfs_io -c "pwrite 0 4k" /mnt/ext4/testfile umount /mnt/ext4 e2fsck -nf /dev/sda6 ... Inode 53, i_blocks is 16, should be 8. Fix? no ... Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
| * | ext4: be more strict when migrating to non-extent based fileEryu Guan2015-07-031-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the check in ext4_ind_migrate() is not enough before doing the real conversion: a) delayed allocated extents could bypass the check on eh->eh_entries and eh->eh_depth This can be demonstrated by this script xfs_io -fc "pwrite 0 4k" -c "pwrite 8k 4k" /mnt/ext4/testfile chattr -e /mnt/ext4/testfile where testfile has two extents but still be converted to non-extent based file format. b) only extent length is checked but not the offset, which would result in data lose (delalloc) or fs corruption (nodelalloc), because non-extent based file only supports at most (12 + 2^10 + 2^20 + 2^30) blocks This can be demostrated by xfs_io -fc "pwrite 5T 4k" /mnt/ext4/testfile chattr -e /mnt/ext4/testfile sync If delalloc is enabled, dmesg prints EXT4-fs warning (device dm-4): ext4_block_to_path:105: block 1342177280 > max in inode 53 EXT4-fs (dm-4): Delayed block allocation failed for inode 53 at logical offset 1342177280 with max blocks 1 with error 5 EXT4-fs (dm-4): This should not happen!! Data will be lost If delalloc is disabled, e2fsck -nf shows corruption Inode 53, i_size is 5497558142976, should be 4096. Fix? no Fix the two issues by a) forcing all delayed allocation blocks to be allocated before checking eh->eh_depth and eh->eh_entries b) limiting the last logical block of the extent is within direct map Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
| * | ext4: fix reservation release on invalidatepage for delalloc fsLukas Czerner2015-07-031-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On delalloc enabled file system on invalidatepage operation in ext4_da_page_release_reservation() we want to clear the delayed buffer and remove the extent covering the delayed buffer from the extent status tree. However currently there is a bug where on the systems with page size > block size we will always remove extents from the start of the page regardless where the actual delayed buffers are positioned in the page. This leads to the errors like this: EXT4-fs warning (device loop0): ext4_da_release_space:1225: ext4_da_release_space: ino 13, to_free 1 with only 0 reserved data blocks This however can cause data loss on writeback time if the file system is in ENOSPC condition because we're releasing reservation for someones else delayed buffer. Fix this by only removing extents that corresponds to the part of the page we want to invalidate. This problem is reproducible by the following fio receipt (however I was only able to reproduce it with fio-2.1 or older. [global] bs=8k iodepth=1024 iodepth_batch=60 randrepeat=1 size=1m directory=/mnt/test numjobs=20 [job1] ioengine=sync bs=1k direct=1 rw=randread filename=file1:file2 [job2] ioengine=libaio rw=randwrite direct=1 filename=file1:file2 [job3] bs=1k ioengine=posixaio rw=randwrite direct=1 filename=file1:file2 [job5] bs=1k ioengine=sync rw=randread filename=file1:file2 [job7] ioengine=libaio rw=randwrite filename=file1:file2 [job8] ioengine=posixaio rw=randwrite filename=file1:file2 [job10] ioengine=mmap rw=randwrite bs=1k filename=file1:file2 [job11] ioengine=mmap rw=randwrite direct=1 filename=file1:file2 Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org
| * | ext4: avoid deadlocks in the writeback path by using sb_getblk_gfpNikolay Borisov2015-07-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Switch ext4 to using sb_getblk_gfp with GFP_NOFS added to fix possible deadlocks in the page writeback path. Signed-off-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
| * | ext4: fix fencepost error in lazytime optimizationTheodore Ts'o2015-07-011-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8f4d8558391: "ext4: fix lazytime optimization" was not a complete fix. In the case where the inode number is a multiple of 16, and we could still end up updating an inode with dirty timestamps written to the wrong inode on disk. Oops. This can be easily reproduced by using generic/005 with a file system with metadata_csum and lazytime enabled. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
* | | Merge branch 'for-linus' of ↵Linus Torvalds2015-07-0469-467/+657
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
| * | | dax: bdev_direct_access() may sleepMatthew Wilcox2015-07-041-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The brd driver is the only in-tree driver that may sleep currently. After some discussion on linux-fsdevel, we decided that any driver may choose to sleep in its ->direct_access method. To ensure that all callers of bdev_direct_access() are prepared for this, add a call to might_sleep(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | block: Add support for DAX reads/writes to block devicesMatthew Wilcox2015-07-042-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a block device supports the ->direct_access methods, bypass the normal DIO path and use DAX to go straight to memcpy() instead of allocating a DIO and a BIO. Includes support for the DIO_SKIP_DIO_COUNT flag in DAX, as is done in do_blockdev_direct_IO(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | dax: Use copy_from_iter_nocacheMatthew Wilcox2015-07-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When userspace does a write, there's no need for the written data to pollute the CPU cache. This matches the original XIP code. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs/file.c: __fget() and dup2() atomicity rulesEric Dumazet2015-07-011-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __fget() does lockless fetch of pointer from the descriptor table, attempts to grab a reference and treats "it was already zero" as "it's already gone from the table, we just hadn't seen the store, let's fail". Unfortunately, that breaks the atomicity of dup2() - __fget() might see the old pointer, notice that it's been already dropped and treat that as "it's closed". What we should be getting is either the old file or new one, depending whether we come before or after dup2(). Dmitry had following test failing sometimes : int fd; void *Thread(void *x) { char buf; int n = read(fd, &buf, 1); if (n != 1) exit(printf("read failed: n=%d errno=%d\n", n, errno)); return 0; } int main() { fd = open("/dev/urandom", O_RDONLY); int fd2 = open("/dev/urandom", O_RDONLY); if (fd == -1 || fd2 == -1) exit(printf("open failed\n")); pthread_t th; pthread_create(&th, 0, Thread, 0); if (dup2(fd2, fd) == -1) exit(printf("dup2 failed\n")); pthread_join(th, 0); if (close(fd) == -1) exit(printf("close failed\n")); if (close(fd2) == -1) exit(printf("close failed\n")); printf("DONE\n"); return 0; } Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs/file.c: don't acquire files->file_lock in fd_install()Eric Dumazet2015-07-011-19/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mateusz Guzik reported : Currently obtaining a new file descriptor results in locking fdtable twice - once in order to reserve a slot and second time to fill it. Holding the spinlock in __fd_install() is needed in case a resize is done, or to prevent a resize. Mateusz provided an RFC patch and a micro benchmark : http://people.redhat.com/~mguzik/pipebench.c A resize is an unlikely operation in a process lifetime, as table size is at least doubled at every resize. We can use RCU instead of the spinlock. __fd_install() must wait if a resize is in progress. The resize must block new __fd_install() callers from starting, and wait that ongoing install are finished (synchronize_sched()) resize should be attempted by a single thread to not waste resources. rcu_sched variant is used, as __fd_install() and expand_fdtable() run from process context. It gives us a ~30% speedup using pipebench on a dual Intel(R) Xeon(R) CPU E5-2696 v2 @ 2.50GHz Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Mateusz Guzik <mguzik@redhat.com> Tested-by: Mateusz Guzik <mguzik@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper ↵Wang YanQing2015-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | limitation Execution of get_anon_bdev concurrently and preemptive kernel all could bring race condition, it isn't enough to check dev against its upper limitation with equality operator only. This patch fix it. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | vfs: avoid creation of inode number 0 in get_next_inoCarlos Maiolino2015-06-301-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | currently, get_next_ino() is able to create inodes with inode number = 0. This have a bad impact in the filesystems relying in this function to generate inode numbers. While there is no problem at all in having inodes with number 0, userspace tools which handle file management tasks can have problems handling these files, like for example, the impossiblity of users to delete these files, since glibc will ignore them. So, I believe the best way is kernel to avoid creating them. This problem has been raised previously, but the old thread didn't have any other update for a year+, and I've seen too many users hitting the same issue regarding the impossibility to delete files while using filesystems relying on this function. So, I'm starting the thread again, with the same patch that I believe is enough to address this problem. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | namei: make set_root_rcu() return voidAl Viro2015-06-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only caller that cares about its return value can just as easily pick it from nd->root_seq itself. We used to just calculate it and return to caller, but these days we are storing it in nd->root_seq in all cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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