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2015-10-25Btrfs: fix regression running delayed references when using qgroupsFilipe Manana
In the kernel 4.2 merge window we had a big changes to the implementation of delayed references and qgroups which made the no_quota field of delayed references not used anymore. More specifically the no_quota field is not used anymore as of: commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.") Leaving the no_quota field actually prevents delayed references from getting merged, which in turn cause the following BUG_ON(), at fs/btrfs/extent-tree.c, to be hit when qgroups are enabled: static int run_delayed_tree_ref(...) { (...) BUG_ON(node->ref_mod != 1); (...) } This happens on a scenario like the following: 1) Ref1 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. 2) Ref2 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with Ref1 because Ref1->no_quota != Ref2->no_quota. 3) Ref3 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref2 is incompatible due to Ref2->no_quota != Ref3->no_quota. 4) Ref4 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref3 is incompatible due to Ref3->no_quota != Ref4->no_quota. 5) We run delayed references, trigger merging of delayed references, through __btrfs_run_delayed_refs() -> btrfs_merge_delayed_refs(). 6) Ref1 and Ref3 are merged as Ref1->no_quota = Ref3->no_quota and all other conditions are satisfied too. So Ref1 gets a ref_mod value of 2. 7) Ref2 and Ref4 are merged as Ref2->no_quota = Ref4->no_quota and all other conditions are satisfied too. So Ref2 gets a ref_mod value of 2. 8) Ref1 and Ref2 aren't merged, because they have different values for their no_quota field. 9) Delayed reference Ref1 is picked for running (select_delayed_ref() always prefers references with an action == BTRFS_ADD_DELAYED_REF). So run_delayed_tree_ref() is called for Ref1 which triggers the BUG_ON because Ref1->red_mod != 1 (equals 2). So fix this by removing the no_quota field, as it's not used anymore as of commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism."). The use of no_quota was also buggy in at least two places: 1) At delayed-refs.c:btrfs_add_delayed_tree_ref() - we were setting no_quota to 0 instead of 1 when the following condition was true: is_fstree(ref_root) || !fs_info->quota_enabled 2) At extent-tree.c:__btrfs_inc_extent_ref() - we were attempting to reset a node's no_quota when the condition "!is_fstree(root_objectid) || !root->fs_info->quota_enabled" was true but we did it only in an unused local stack variable, that is, we never reset the no_quota value in the node itself. This fixes the remainder of problems several people have been having when running delayed references, mostly while a balance is running in parallel, on a 4.2+ kernel. Very special thanks to Stéphane Lesimple for helping debugging this issue and testing this fix on his multi terabyte filesystem (which took more than one day to balance alone, plus fsck, etc). Also, this fixes deadlock issue when using the clone ioctl with qgroups enabled, as reported by Elias Probst in the mailing list. The deadlock happens because after calling btrfs_insert_empty_item we have our path holding a write lock on a leaf of the fs/subvol tree and then before releasing the path we called check_ref() which did backref walking, when qgroups are enabled, and tried to read lock the same leaf. The trace for this case is the following: INFO: task systemd-nspawn:6095 blocked for more than 120 seconds. (...) Call Trace: [<ffffffff86999201>] schedule+0x74/0x83 [<ffffffff863ef64c>] btrfs_tree_read_lock+0xc0/0xea [<ffffffff86137ed7>] ? wait_woken+0x74/0x74 [<ffffffff8639f0a7>] btrfs_search_old_slot+0x51a/0x810 [<ffffffff863a129b>] btrfs_next_old_leaf+0xdf/0x3ce [<ffffffff86413a00>] ? ulist_add_merge+0x1b/0x127 [<ffffffff86411688>] __resolve_indirect_refs+0x62a/0x667 [<ffffffff863ef546>] ? btrfs_clear_lock_blocking_rw+0x78/0xbe [<ffffffff864122d3>] find_parent_nodes+0xaf3/0xfc6 [<ffffffff86412838>] __btrfs_find_all_roots+0x92/0xf0 [<ffffffff864128f2>] btrfs_find_all_roots+0x45/0x65 [<ffffffff8639a75b>] ? btrfs_get_tree_mod_seq+0x2b/0x88 [<ffffffff863e852e>] check_ref+0x64/0xc4 [<ffffffff863e9e01>] btrfs_clone+0x66e/0xb5d [<ffffffff863ea77f>] btrfs_ioctl_clone+0x48f/0x5bb [<ffffffff86048a68>] ? native_sched_clock+0x28/0x77 [<ffffffff863ed9b0>] btrfs_ioctl+0xabc/0x25cb (...) The problem goes away by eleminating check_ref(), which no longer is needed as its purpose was to get a value for the no_quota field of a delayed reference (this patch removes the no_quota field as mentioned earlier). Reported-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Tested-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Reported-by: Elias Probst <mail@eliasprobst.eu> Reported-by: Peter Becker <floyd.net@gmail.com> Reported-by: Malte Schröder <malte@tnxip.de> Reported-by: Derek Dongray <derek@valedon.co.uk> Reported-by: Erkki Seppala <flux-btrfs@inside.org> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
2015-10-12Merge branch 'fix/waitqueue-barriers' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
2015-10-10btrfs: remove extra barrier before waitqueue_activeDavid Sterba
Removing barriers is scary, but a call to atomic_dec_and_test implies a barrier, so we don't need to issue another one. Signed-off-by: David Sterba <dsterba@suse.com>
2015-10-10btrfs: comment waitqueue_active implied by locksDavid Sterba
Suggested-by: Chris Mason <clm@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-09-29Btrfs: consolidate btrfs_error() to btrfs_std_error()Anand Jain
btrfs_error() and btrfs_std_error() does the same thing and calls _btrfs_std_error(), so consolidate them together. And the main motivation is that btrfs_error() is closely named with btrfs_err(), one handles error action the other is to log the error, so don't closely name them. Signed-off-by: Anand Jain <anand.jain@oracle.com> Suggested-by: David Sterba <dsterba@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-08-19Btrfs: fix file read corruption after extent cloning and fsyncFilipe Manana
If we partially clone one extent of a file into a lower offset of the file, fsync the file, power fail and then mount the fs to trigger log replay, we can get multiple checksum items in the csum tree that overlap each other and result in checksum lookup failures later. Those failures can make file data read requests assume a checksum value of 0, but they will not return an error (-EIO for example) to userspace exactly because the expected checksum value 0 is a special value that makes the read bio endio callback return success and set all the bytes of the corresponding page with the value 0x01 (at fs/btrfs/inode.c:__readpage_endio_check()). From a userspace perspective this is equivalent to file corruption because we are not returning what was written to the file. Details about how this can happen, and why, are included inline in the following reproducer test case for fstests and the comment added to tree-log.c. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _require_cloner _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with a single 100K extent starting at file # offset 800K. We fsync the file here to make the fsync log tree gets # a single csum item that covers the whole 100K extent, which causes # the second fsync, done after the cloning operation below, to not # leave in the log tree two csum items covering two sub-ranges # ([0, 20K[ and [20K, 100K[)) of our extent. $XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone part of our extent into file offset 400K. This adds a file # extent item to our inode's metadata that points to the 100K extent # we created before, using a data offset of 20K and a data length of # 20K, so that it refers to the sub-range [20K, 40K[ of our original # extent. $CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \ -l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo # Now fsync our file to make sure the extent cloning is durably # persisted. This fsync will not add a second csum item to the log # tree containing the checksums for the blocks in the sub-range # [20K, 40K[ of our extent, because there was already a csum item in # the log tree covering the whole extent, added by the first fsync # we did before. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo echo "File digest before power failure:" md5sum $SCRATCH_MNT/foo | _filter_scratch # Silently drop all writes and ummount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. # The fsync log replay first processes the file extent item # corresponding to the file offset 400K (the one which refers to the # [20K, 40K[ sub-range of our 100K extent) and then processes the file # extent item for file offset 800K. It used to happen that when # processing the later, it erroneously left in the csum tree 2 csum # items that overlapped each other, 1 for the sub-range [20K, 40K[ and # 1 for the whole range of our extent. This introduced a problem where # subsequent lookups for the checksums of blocks within the range # [40K, 100K[ of our extent would not find anything because lookups in # the csum tree ended up looking only at the smaller csum item, the # one covering the subrange [20K, 40K[. This made read requests assume # an expected checksum with a value of 0 for those blocks, which caused # checksum verification failure when the read operations finished. # However those checksum failure did not result in read requests # returning an error to user space (like -EIO for e.g.) because the # expected checksum value had the special value 0, and in that case # btrfs set all bytes of the corresponding pages with the value 0x01 # and produce the following warning in dmesg/syslog: # # "BTRFS warning (device dm-0): csum failed ino 257 off 917504 csum\ # 1322675045 expected csum 0" # _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File digest after log replay:" # Must match the same digest he had after cloning the extent and # before the power failure happened. md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey status=0 exit 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>
2015-08-19btrfs: Remove unused arguments in tree-log.cZhaolei
Following arguments are not used in tree-log.c: insert_one_name(): path, type wait_log_commit(): trans wait_for_writer(): trans This patch remove them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-19btrfs: Remove useless condition in start_log_trans()Zhaolei
Dan Carpenter <dan.carpenter@oracle.com> reported a smatch warning for start_log_trans(): fs/btrfs/tree-log.c:178 start_log_trans() warn: we tested 'root->log_root' before and it was 'false' fs/btrfs/tree-log.c 147 if (root->log_root) { We test "root->log_root" here. ... Reason: Condition of: fs/btrfs/tree-log.c:178: if (!root->log_root) { is not necessary after commit: 7237f1833 It caused a smatch warning, and no functionally error. Fix: Deleting above condition will make smatch shut up, but a better way is to do cleanup for start_log_trans() to remove duplicated code and make code more readable. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix stale dir entries after removing a link and fsyncFilipe Manana
We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix stale directory entries after fsync log replayFilipe Manana
We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-01Btrfs: fix fsync after truncate when no_holes feature is enabledFilipe Manana
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>
2015-06-30Btrfs: fix fsync xattr loss in the fast fsync pathFilipe Manana
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>
2015-06-30Btrfs: fix fsync data loss after append writeFilipe Manana
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>
2015-06-03Btrfs: remove csum_bytes_leftLiu Bo
After commit 8407f553268a ("Btrfs: fix data corruption after fast fsync and writeback error"), during wait_ordered_extents(), we wait for ordered extent setting BTRFS_ORDERED_IO_DONE or BTRFS_ORDERED_IOERR, at which point we've already got checksum information, so we don't need to check (csum_bytes_left == 0) in the whole logging path. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-04-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells
that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-10btrfs: actively run the delayed refs while deleting large filesChris Mason
When we are deleting large files with large extents, we are building up a huge set of delayed refs for processing. Truncate isn't checking often enough to see if we need to back off and process those, or let a commit proceed. The end result is long stalls after the rm, and very long commit times. During the commits, other processes back up waiting to start new transactions and we get into trouble. Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26Btrfs: fix metadata inconsistencies after directory fsyncFilipe Manana
We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-26Btrfs: remove deleted xattrs on fsync log replayFilipe Manana
If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-25Merge branch 'cleanups-post-3.19' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1 Signed-off-by: Chris Mason <clm@fb.com> Conflicts: fs/btrfs/disk-io.c
2015-03-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Outside of misc fixes, Filipe has a few fsync corners and we're pulling in one more of Josef's fixes from production use here" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref. Btrfs: fix data loss in the fast fsync path Btrfs: remove extra run_delayed_refs in update_cowonly_root Btrfs: incremental send, don't rename a directory too soon btrfs: fix lost return value due to variable shadowing Btrfs: do not ignore errors from btrfs_lookup_xattr in do_setxattr Btrfs: fix off-by-one logic error in btrfs_realloc_node Btrfs: add missing inode update when punching hole Btrfs: abort the transaction if we fail to update the free space cache inode Btrfs: fix fsync race leading to ordered extent memory leaks
2015-03-05Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.Quentin Casasnovas
Improper arithmetics when calculting the address of the extended ref could lead to an out of bounds memory read and kernel panic. Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> cc: stable@vger.kernel.org # v3.7+ Signed-off-by: Chris Mason <clm@fb.com>
2015-02-19Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This pull is mostly cleanups and fixes: - The raid5/6 cleanups from Zhao Lei fixup some long standing warts in the code and add improvements on top of the scrubbing support from 3.19. - Josef has round one of our ENOSPC fixes coming from large btrfs clusters here at FB. - Dave Sterba continues a long series of cleanups (thanks Dave), and Filipe continues hammering on corner cases in fsync and others This all was held up a little trying to track down a use-after-free in btrfs raid5/6. It's not clear yet if this is just made easier to trigger with this pull or if its a new bug from the raid5/6 cleanups. Dave Sterba is the only one to trigger it so far, but he has a consistent way to reproduce, so we'll get it nailed shortly" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (68 commits) Btrfs: don't remove extents and xattrs when logging new names Btrfs: fix fsync data loss after adding hard link to inode Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group Btrfs: account for large extents with enospc Btrfs: don't set and clear delalloc for O_DIRECT writes Btrfs: only adjust outstanding_extents when we do a short write btrfs: Fix out-of-space bug Btrfs: scrub, fix sleep in atomic context Btrfs: fix scheduler warning when syncing log Btrfs: Remove unnecessary placeholder in btrfs_err_code btrfs: cleanup init for list in free-space-cache btrfs: delete chunk allocation attemp when setting block group ro btrfs: clear bio reference after submit_one_bio() Btrfs: fix scrub race leading to use-after-free Btrfs: add missing cleanup on sysfs init failure Btrfs: fix race between transaction commit and empty block group removal btrfs: add more checks to btrfs_read_sys_array btrfs: cleanup, rename a few variables in btrfs_read_sys_array btrfs: add checks for sys_chunk_array sizes btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize ...
2015-02-16Btrfs: disk-io: replace root args iff only fs_info usedDaniel Dressler
This is the 3rd independent patch of a larger project to cleanup btrfs's internal usage of btrfs_root. Many functions take btrfs_root only to grab the fs_info struct. By requiring a root these functions cause programmer overhead. That these functions can accept any valid root is not obvious until inspection. This patch reduces the specificity of such functions to accept the fs_info directly. These patches can be applied independently and thus are not being submitted as a patch series. There should be about 26 patches by the project's completion. Each patch will cleanup between 1 and 34 functions apiece. Each patch covers a single file's functions. This patch affects the following function(s): 1) csum_tree_block 2) csum_dirty_buffer 3) check_tree_block_fsid 4) btrfs_find_tree_block 5) clean_tree_block Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-14Btrfs: don't remove extents and xattrs when logging new namesFilipe Manana
If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: fix fsync data loss after adding hard link to inodeFilipe Manana
We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: fix scheduler warning when syncing logFilipe Manana
We try to lock a mutex while the current task state is not TASK_RUNNING, which results in the following warning when CONFIG_DEBUG_LOCK_ALLOC=y: [30736.772501] ------------[ cut here ]------------ [30736.774545] WARNING: CPU: 9 PID: 19972 at kernel/sched/core.c:7300 __might_sleep+0x8b/0xa8() [30736.783453] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff8107499b>] prepare_to_wait+0x43/0x89 [30736.786261] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc psmouse parport pcspkr microcode serio_raw evdev processor thermal_sys i2c_piix4 i2c_core button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring e1000 virtio scsi_mod [30736.794323] CPU: 9 PID: 19972 Comm: fsstress Not tainted 3.19.0-rc7-btrfs-next-5+ #1 [30736.795821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [30736.798788] 0000000000000009 ffff88042743fbd8 ffffffff814248ed ffff88043d32f2d8 [30736.800504] ffff88042743fc28 ffff88042743fc18 ffffffff81045338 0000000000000001 [30736.802131] ffffffff81064514 ffffffff817c52d1 000000000000026d 0000000000000000 [30736.803676] Call Trace: [30736.804256] [<ffffffff814248ed>] dump_stack+0x4c/0x65 [30736.805245] [<ffffffff81045338>] warn_slowpath_common+0xa1/0xbb [30736.806360] [<ffffffff81064514>] ? __might_sleep+0x8b/0xa8 [30736.807391] [<ffffffff81045398>] warn_slowpath_fmt+0x46/0x48 [30736.808511] [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89 [30736.809620] [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89 [30736.810691] [<ffffffff81064514>] __might_sleep+0x8b/0xa8 [30736.811703] [<ffffffff81426eaf>] mutex_lock_nested+0x2f/0x3a0 [30736.812889] [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab [30736.814138] [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf [30736.819878] [<ffffffffa038cfff>] wait_for_writer.isra.12+0x91/0xaa [btrfs] [30736.821260] [<ffffffff810748bd>] ? signal_pending_state+0x31/0x31 [30736.822410] [<ffffffffa0391f0a>] btrfs_sync_log+0x160/0x947 [btrfs] [30736.823574] [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab [30736.824847] [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf [30736.825972] [<ffffffffa036e555>] btrfs_sync_file+0x2b0/0x319 [btrfs] [30736.827684] [<ffffffff8117901a>] vfs_fsync_range+0x21/0x23 [30736.828932] [<ffffffff81179038>] vfs_fsync+0x1c/0x1e [30736.829917] [<ffffffff8117928b>] do_fsync+0x34/0x4e [30736.830862] [<ffffffff811794b3>] SyS_fsync+0x10/0x14 [30736.831819] [<ffffffff8142a512>] system_call_fastpath+0x12/0x17 [30736.832982] ---[ end trace c0b57df60d32ae5c ]--- Fix this my acquiring the mutex after calling finish_wait(), which sets the task's state to TASK_RUNNING. 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>
2015-02-04Btrfs: add missing blk_finish_plug in btrfs_sync_log()Forrest Liu
Add missing blk_finish_plug in btrfs_sync_log() Signed-off-by: Forrest Liu <forrestl@synology.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-02btrfs: kill btrfs_inode_*time helpersDavid Sterba
They just opencode taking address of the timespec member. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefsFilipe Manana
If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21Btrfs: fix fsync when extend references are added to an inodeFilipe Manana
If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21Btrfs: fix directory inconsistency after fsync log replayFilipe Manana
If we have an inode (file) with a link count greater than 1, remove one of its hard links, fsync the inode, power fail/crash and then replay the fsync log on the next mount, we end up getting the parent directory's metadata inconsistent - its i_size still reflects the deleted hard link and has dangling index entries (with no matching inode reference entries). This prevents the directory from ever being deletable, as its i_size can never decrease to BTRFS_EMPTY_DIR_SIZE even if all of its children inodes are deleted, and the dangling index entries can never be removed (as they point to an inode that does not exist anymore). This is easy to reproduce with the following excerpt from the test case for xfstests that I just made: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 2 hard links in the same directory. mkdir -p $SCRATCH_MNT/a/b echo "hello world" > $SCRATCH_MNT/a/b/foo ln $SCRATCH_MNT/a/b/foo $SCRATCH_MNT/a/b/bar # Make sure all metadata and data are durably persisted. sync # Now remove one of the hard links and fsync the inode. rm -f $SCRATCH_MNT/a/b/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a/b/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Remove the last hard link of the file and attempt to remove its parent # directory - this failed in btrfs because the fsync log and replay code # didn't decrement the parent directory's i_size and left dangling directory # index entries - this made the btrfs rmdir implementation always fail with # the error -ENOTEMPTY. # # The dangling directory index entries were visible to user space, but it was # impossible to do anything on them (unlink, open, read, write, stat, etc) # because the inode they pointed to did not exist anymore. # # The parent directory's metadata inconsistency (stale index entries) was # also detected by btrfs' fsck tool, which is run automatically by the fstests # framework when the test finishes. The error message reported by fsck was: # # root 5 inode 259 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 3 namelen 3 name bar filetype 1 errors 4, no inode ref # rm -f $SCRATCH_MNT/a/b/* rmdir $SCRATCH_MNT/a/b rmdir $SCRATCH_MNT/a To fix this just make sure that after an unlink, if the inode is fsync'ed, he parent inode is fully logged in the fsync log. A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-21Merge branch 'cleanup/blocksize-diet-part2' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
2015-01-14btrfs: simplify insert_orphan_itemDavid Sterba
We can search and add the orphan item in one go, btrfs_insert_orphan_item will find out if the item already exists. Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-14btrfs: fix leak of path in btrfs_find_itemDavid Sterba
If btrfs_find_item is called with NULL path it allocates one locally but does not free it. Affected paths are inserting an orphan item for a file and for a subvol root. Move the path allocation to the callers. CC: <stable@vger.kernel.org> # 3.14+ Fixes: 3f870c289900 ("btrfs: expand btrfs_find_item() to include find_orphan_item functionality") Signed-off-by: David Sterba <dsterba@suse.cz>
2014-12-12btrfs: sink blocksize parameter to btrfs_find_create_tree_blockDavid Sterba
Finally it's clear that the requested blocksize is always equal to nodesize, with one exception, the superblock. Superblock has fixed size regardless of the metadata block size, but uses the same helpers to initialize sys array/chunk tree and to work with the chunk items. So it pretends to be an extent_buffer for a moment, btrfs_read_sys_array is full of special cases, we're adding one more. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-11-21Btrfs: ensure ordered extent errors aren't missed on fsyncFilipe Manana
When doing a fsync with a fast path we have a time window where we can miss the fact that writeback of some file data failed, and therefore we endup returning success (0) from fsync when we should return an error. The steps that lead to this are the following: 1) We start all ordered extents by calling filemap_fdatawrite_range(); 2) We do some other work like locking the inode's i_mutex, start a transaction, start a log transaction, etc; 3) We enter btrfs_log_inode(), acquire the inode's log_mutex and collect all the ordered extents from inode's ordered tree into a list; 4) But by the time we do ordered extent collection, some ordered extents we started at step 1) might have already completed with an error, and therefore we didn't found them in the ordered tree and had no idea they finished with an error. This makes our fsync return success (0) to userspace, but has no bad effects on the log like for example insertion of file extent items into the log that point to unwritten extents, because the invalid extent maps were removed before the ordered extent completed (in inode.c:btrfs_finish_ordered_io). So after collecting the ordered extents just check if the inode's i_mapping has any error flags set (AS_EIO or AS_ENOSPC) and leave with an error if it does. Whenever writeback fails for a page of an ordered extent, we call mapping_set_error (done in extent_io.c:end_extent_writepage, called by extent_io.c:end_bio_extent_writepage) that sets one of those error flags in the inode's i_mapping flags. This change also has the side effect of fixing the issue where for fast fsyncs we never checked/cleared the error flags from the inode's i_mapping flags, which means that a full fsync performed after a fast fsync could get such errors that belonged to the fast fsync - because the full fsync calls btrfs_wait_ordered_range() which calls filemap_fdatawait_range(), and the later checks for and clears those flags, while for fast fsyncs we never call filemap_fdatawait_range() or anything else that checks for and clears the error flags from the inode's i_mapping. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-21Btrfs: collect only the necessary ordered extents on ranged fsyncFilipe Manana
Instead of collecting all ordered extents from the inode's ordered tree and then wait for all of them to complete, just collect the ones that overlap the fsync range. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-21Btrfs: don't ignore log btree writeback errorsFilipe Manana
If an error happens during writeback of log btree extents, make sure the error is returned to the caller (fsync), so that it takes proper action (commit current transaction) instead of writing a superblock that points to log btrees with all or some nodes that weren't durably persisted. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-21Btrfs: make sure logged extents complete in the current transaction V3Josef Bacik
Liu Bo pointed out that my previous fix would lose the generation update in the scenario I described. It is actually much worse than that, we could lose the entire extent if we lose power right after the transaction commits. Consider the following write extent 0-4k log extent in log tree commit transaction < power fail happens here ordered extent completes We would lose the 0-4k extent because it hasn't updated the actual fs tree, and the transaction commit will reset the log so it isn't replayed. If we lose power before the transaction commit we are save, otherwise we are not. Fix this by keeping track of all extents we logged in this transaction. Then when we go to commit the transaction make sure we wait for all of those ordered extents to complete before proceeding. This will make sure that if we lose power after the transaction commit we still have our data. This also fixes the problem of the improperly updated extent generation. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-20Btrfs: make sure we wait on logged extents when fsycning two subvolsJosef Bacik
If we have two fsync()'s race on different subvols one will do all of its work to get into the log_tree, wait on it's outstanding IO, and then allow the log_tree to finish it's commit. The problem is we were just free'ing that subvols logged extents instead of waiting on them, so whoever lost the race wouldn't really have their data on disk. Fix this by waiting properly instead of freeing the logged extents. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Filipe is nailing down some problems with our skinny extent variation, and Dave's patch fixes endian problems in the new super block checks" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix race that makes btrfs_lookup_extent_info miss skinny extent items Btrfs: properly clean up btrfs_end_io_wq_cache Btrfs: fix invalid leaf slot access in btrfs_lookup_extent() btrfs: use macro accessors in superblock validation checks
2014-10-27Btrfs: fix invalid leaf slot access in btrfs_lookup_extent()Filipe Manana
If we couldn't find our extent item, we accessed the current slot (path->slots[0]) to check if it corresponds to an equivalent skinny metadata item. However this slot could be beyond our last item in the leaf (i.e. path->slots[0] >= btrfs_header_nritems(leaf)), in which case we shouldn't process it. Since btrfs_lookup_extent() is only used to find extent items for data extents, fix this by removing completely the logic that looks up for an equivalent skinny metadata item, since it can not exist. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "The largest set of changes here come from Miao Xie. He's cleaning up and improving read recovery/repair for raid, and has a number of related fixes. I've merged another set of fsync fixes from Filipe, and he's also improved the way we handle metadata write errors to make sure we force the FS readonly if things go wrong. Otherwise we have a collection of fixes and cleanups. Dave Sterba gets a cookie for removing the most lines (thanks Dave)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (139 commits) btrfs: Fix compile error when CONFIG_SECURITY is not set. Btrfs: fix compiles when CONFIG_BTRFS_FS_RUN_SANITY_TESTS is off btrfs: Make btrfs handle security mount options internally to avoid losing security label. Btrfs: send, don't delay dir move if there's a new parent inode btrfs: add more superblock checks Btrfs: fix race in WAIT_SYNC ioctl Btrfs: be aware of btree inode write errors to avoid fs corruption Btrfs: remove redundant btrfs_verify_qgroup_counts declaration. btrfs: fix shadow warning on cmp Btrfs: fix compilation errors under DEBUG Btrfs: fix crash of btrfs_release_extent_buffer_page Btrfs: add missing end_page_writeback on submit_extent_page failure btrfs: Fix the wrong condition judgment about subset extent map Btrfs: fix build_backref_tree issue with multiple shared blocks Btrfs: cleanup error handling in build_backref_tree btrfs: move checks for DUMMY_ROOT into a helper btrfs: new define for the inline extent data start btrfs: kill extent_buffer_page helper btrfs: drop constant param from btrfs_release_extent_buffer_page btrfs: hide typecast to definition of BTRFS_SEND_TRANS_STUB ...
2014-10-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull "trivial tree" updates from Jiri Kosina: "Usual pile from trivial tree everyone is so eagerly waiting for" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Remove MN10300_PROC_MN2WS0038 mei: fix comments treewide: Fix typos in Kconfig kprobes: update jprobe_example.c for do_fork() change Documentation: change "&" to "and" in Documentation/applying-patches.txt Documentation: remove obsolete pcmcia-cs from Changes Documentation: update links in Changes Documentation: Docbook: Fix generated DocBook/kernel-api.xml score: Remove GENERIC_HAS_IOMAP gpio: fix 'CONFIG_GPIO_IRQCHIP' comments tty: doc: Fix grammar in serial/tty dma-debug: modify check_for_stack output treewide: fix errors in printk genirq: fix reference in devm_request_threaded_irq comment treewide: fix synchronize_rcu() in comments checkstack.pl: port to AArch64 doc: queue-sysfs: minor fixes init/do_mounts: better syntax description MIPS: fix comment spelling powerpc/simpleboot: fix comment ...
2014-09-19Btrfs: fix data corruption after fast fsync and writeback errorFilipe Manana
When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: fix directory recovery from fsync logFilipe Manana
When replaying a directory from the fsync log, if a directory entry exists both in the fs/subvol tree and in the log, the directory's inode got its i_size updated incorrectly, accounting for the dentry's name twice. Reproducer, from a test for xfstests: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey touch $SCRATCH_MNT/foo sync touch $SCRATCH_MNT/bar xfs_io -c "fsync" $SCRATCH_MNT xfs_io -c "fsync" $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey [ -f $SCRATCH_MNT/foo ] || echo "file foo is missing" [ -f $SCRATCH_MNT/bar ] || echo "file bar is missing" _unmount_flakey _check_scratch_fs $FLAKEY_DEV The filesystem check at the end failed with the message: "root 5 root dir 256 error". A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: make btrfs_search_forward return with nodes unlockedFilipe Manana
None of the uses of btrfs_search_forward() need to have the path nodes (level >= 1) read locked, only the leaf needs to be locked while the caller processes it. Therefore make it return a path with all nodes unlocked, except for the leaf. This change is motivated by the observation that during a file fsync we repeatdly call btrfs_search_forward() and process the returned leaf while upper nodes of the returned path (level >= 1) are read locked, which unnecessarily blocks other tasks that want to write to the same fs/subvol btree. Therefore instead of modifying the fsync code to unlock all nodes with level >= 1 immediately after calling btrfs_search_forward(), change btrfs_search_forward() to do it, so that it benefits all callers. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17btrfs: use nodesize everywhere, kill leafsizeDavid Sterba
The nodesize and leafsize were never of different values. Unify the usage and make nodesize the one. Cleanup the redundant checks and helpers. Shaves a few bytes from .text: text data bss dec hex filename 852418 24560 23112 900090 dbbfa btrfs.ko.before 851074 24584 23112 898770 db6d2 btrfs.ko.after Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17btrfs: kill the key type accessor helpersDavid Sterba
btrfs_set_key_type and btrfs_key_type are used inconsistently along with open coded variants. Other members of btrfs_key are accessed directly without any helpers anyway. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>