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2015-08-09Merge branch 'jeffm-discard-4.3' into for-linus-4.3Chris Mason
2015-08-09Btrfs: add support for blkio controllersChris Mason
This attaches accounting information to bios as we submit them so the new blkio controllers can throttle on btrfs filesystems. Not much is required, we're just associating bios with blkcgs during clone, calling wbc_init_bio()/wbc_account_io() during writepages submission, and attaching the bios to the current context during direct IO. Finally if we are splitting bios during btrfs_map_bio, this attaches accounting information to the split. The end result is able to throttle nicely on single disk filesystems. A little more work is required for multi-device filesystems. Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: remove unused mutex from struct 'btrfs_fs_info'Byongho Lee
The code using 'ordered_extent_flush_mutex' mutex has removed by below commit. - 8d875f95da43c6a8f18f77869f2ef26e9594fecc btrfs: disable strict file flushes for renames and truncates But the mutex still lives in struct 'btrfs_fs_info'. So, this patch removes the mutex from struct 'btrfs_fs_info' and its initialization code. Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix parity scrub of RAID 5/6 with missing deviceOmar Sandoval
When testing the previous patch, Zhao Lei reported a similar bug when attempting to scrub a degraded RAID 5/6 filesystem with a missing device, leading to NULL pointer dereferences from the RAID 5/6 parity scrubbing code. The first cause was the same as in the previous patch: attempting to call bio_add_page() on a missing block device. To fix this, scrub_extent_for_parity() can just mark the sectors on the missing device as errors instead of attempting to read from it. Additionally, the code uses scrub_remap_extent() to map the extent of the corresponding data stripe, but the extent wasn't already mapped. If scrub_remap_extent() finds a missing block device, it doesn't initialize extent_dev, so we're left with a NULL struct btrfs_device. The solution is to use btrfs_map_block() directly. Reported-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix device replace of a missing RAID 5/6 deviceOmar Sandoval
The original implementation of device replace on RAID 5/6 seems to have missed support for replacing a missing device. When this is attempted, we end up calling bio_add_page() on a bio with a NULL ->bi_bdev, which crashes when we try to dereference it. This happens because btrfs_map_block() has no choice but to return us the missing device because RAID 5/6 don't have any alternate mirrors to read from, and a missing device has a NULL bdev. The idea implemented here is to handle the missing device case separately, which better only happen when we're replacing a missing RAID 5/6 device. We use the new BTRFS_RBIO_REBUILD_MISSING operation to reconstruct the data from parity, check it with scrub_recheck_block_checksum(), and write it out with scrub_write_block_to_dev_replace(). Reported-by: Philip <bugzilla@philip-seeger.de> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96141 Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operationOmar Sandoval
The current RAID 5/6 recovery code isn't quite prepared to handle missing devices. In particular, it expects a bio that we previously attempted to use in the read path, meaning that it has valid pages allocated. However, missing devices have a NULL blkdev, and we can't call bio_add_page() on a bio with a NULL blkdev. We could do manual manipulation of bio->bi_io_vec, but that's pretty gross. So instead, add a separate path that allows us to manually add pages to the rbio. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: count devices correctly in readahead during RAID 5/6 replaceOmar Sandoval
Commit 5fbc7c59fd22 ("Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting") fixed a problem where we would skip a missing device when we shouldn't have because there are no other mirrors to read from in RAID 5/6. After commit 2c8cdd6ee4e7 ("Btrfs, replace: write dirty pages into the replace target device"), the fix doesn't work when we're doing a missing device replace on RAID 5/6 because the replace device is counted as a mirror so we're tricked into thinking we can safely skip the missing device. The fix is to count only the real stripes and decide based on that. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: remove misleading handling of missing device scrubOmar Sandoval
scrub_submit() claims that it can handle a bio with a NULL block device, but this is misleading, as calling bio_add_page() on a bio with a NULL ->bi_bdev would've already crashed. Delete this, as we're about to properly handle a missing block device. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: fix clone / extent-same deadlocksMark Fasheh
Clone and extent same lock their source and target inodes in opposite order. In addition to this, the range locking in clone doesn't take ordering into account. Fix this by having clone use the same locking helpers as btrfs-extent-same. In addition, I do a small cleanup of the locking helpers, removing a case (both inodes being the same) which was poorly accounted for and never actually used by the callers. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix defrag to merge tail file extentLiu Bo
The file layout is [extent 1]...[extent n][4k extent][HOLE][extent x] extent 1~n and 4k extent can be merged during defrag, and the whole defrag bytes is larger than our defrag thresh(256k), 4k extent as a tail is left unmerged since we check if its next extent can be merged (the next one is a hole, so the check will fail), the layout thus can be [new extent][4k extent][HOLE][extent x] (1~n) To fix it, beside looking at the next one, this also looks at the previous one by checking @defrag_end, which is set to 0 when we decide to stop merging contiguous extents, otherwise, we can merge the previous one with our extent. Also, this makes btrfs behave consistent with how xfs and ext4 do. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix warning in backref walkingLiu Bo
When we do backref walking, we search firstly in queued delayed refs and then the on-disk backrefs, but we parse differently for shared references, for delayed refs we also add 'ref->root' while for on-disk backrefs we don't, this can prevent us from merging refs indexed by the same bytenr and cause find_parent_nodes() to throw a warning at 'WARN_ON(ref->count < 0)', for example, when we have a shared data extent with 'ref_cnt=1' and a delayed shared data with a BTRFS_DROP_DELAYED_REF, that happens. For shared references, no matter if it's delayed or on-disk, ref->root is not at all used, instead it's ref->parent that really matters, so this has delayed refs handled as the same way as on-disk refs. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()Zhaolei
When a task trying to double lock a extent buffer, there are no lockdep warning about it because this lock may be in "blocking_lock" state, and make us hard to debug. This patch add a WARN_ON() for above condition, it can not report all deadlock cases(as lock between tasks), but at least helps us some. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Remove root argument in extent_data_ref_count()Zhaolei
Because it is never used. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Fix wrong comment of btrfs_alloc_tree_block()Zhaolei
These wrong comment was copyed from another function(expired) from init, this patch fixed them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: abort transaction on btrfs_reloc_cow_block()Zhaolei
When btrfs_reloc_cow_block() failed in __btrfs_cow_block(), current code just return a err-value to caller, but leave new_created extent buffer exist and locked. Then subsequent code (in relocate) try to lock above eb again, and caused deadlock without any dmesg. (eb lock use wait_event(), so no lockdep message) It is hard to do recover work in __btrfs_cow_block() at this error point, but we can abort transaction to avoid deadlock and operate on unstable state.a It also helps developer to find wrong place quickly. (better than a frozen fs without any dmesg before patch) Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Remove unnecessary variants in relocation.cZhaolei
These arguments are not used in functions, remove them for cleanup and make kernel stack happy. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Cleanup: Remove chunk_objectid argument from btrfs_relocate_chunk()Zhaolei
Remove chunk_objectid argument from btrfs_relocate_chunk() because it is not necessary, it can also cleanup some code in caller for prepare its value. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Cleanup: Remove objectid's init-value in create_reloc_inode()Zhaolei
objectid's init-value is not used in any case, remove it. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Error handle for get_ref_objectid_v0() in relocate_block_group()Zhaolei
We need error checking code for get_ref_objectid_v0() in relocate_block_group(), to avoid unpredictable result, especially for accessing uninitialized value(when function failed) after this line. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Fix data checksum error cause by replace with io-load.Zhaolei
xfstests btrfs/070 sometimes failed. In my test machine, its fail rate is about 30%. In another vm(vmware), its fail rate is about 50%. Reason: btrfs/070 do replace and defrag with fsstress simultaneously, after above operation, checksum error is found by scrub. Actually, it have no relationship with defrag operation, only replace with fsstress can trigger this bug. New data writen to target device have possibility rewrited by old data from source device by replace code in debug, to avoid above problem, we can set target block group to readonly in replace period, so new data requested by other operation will not write to same place with replace code. Before patch(4.1-rc3): 30% failed in 100 xfstests. After patch: 0% failed in 300 xfstests. It also happened in btrfs/071 as it's another scrub with IO load tests. Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: use scrub_pause_on/off() to reduce code in scrub_enumerate_chunks()Zhaolei
Use new intruduced scrub_pause_on/off() can make this code block clean and more readable. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Separate scrub_blocked_if_needed() to scrub_pause_on/off()Zhaolei
It can reduce current duplicated code which is similar to scrub_blocked_if_needed() but can not call it because little different. It also used by my next patch which is in same case. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Use ref_cnt for set_block_group_ro()Zhaolei
More than one code call set_block_group_ro() and restore rw in fail. Old code use bool bit to save blockgroup's ro state, it can not support parallel case(it is confirmd exist in my debug log). This patch use ref count to store ro state, and rename set_block_group_ro/set_block_group_rw to inc_block_group_ro/dec_block_group_ro. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Bypass unrelated items before accessing its contents in scrubZhao Lei
When we access extent_root in scrub_stripe() and scrub_raid56_parity(), we need bypass unrelated tree item firstly before using its contents to do other condition. It is not a bug fix, only making code sequence in logic. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Load only necessary csums into list in scrubZhao Lei
We need not load csum of whole strip in scrub because strip is trimed before use, it is to say, what we really need to calculate csum is data between [extent_logical, extent_len). This patch changed to use above segment for btrfs_lookup_csums_range() in scrub_stripe() Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Fix calculate typo caused by ambiguous meaning of logic_endZhao Lei
For example, in scrub_raid56_parity(), following lines are used to judge is all data processed: place1: if (key.objectid > logic_end) ... place2: if (logic_start >= logic_end) ... ... (place2 is typo, is should be ">", it is copied from other place, where logic_end's meaning is different, long story...) We can fix above typo directly, but the root reason is ambiguous meaning of logic_end in scrub raid56 parity. In other place, XXX_end is pointed to data which is not included, and we need to process segment of [XXX_start, XXX_end). But for scrub raid56 parity, logic_end is pointed to lattest data need to process, and introduced many "+ 1" and "- 1" in code as below: length = sparity->logic_end - sparity->logic_start + 1 logic_end - logic_start + 1 stripe_logical + increment - 1 This patch changed logic_end's meaning to make it in normal understanding in raid56 parity functions and data struct alone with above bugfix. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Free checksum list on scrub_extent() failZhao Lei
When scrub_extent() failed, we need to free previois created checksum list. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Check cancel and pause in interval of scrub operationZhao Lei
Old code checking cancel and pause request inside scrub stripe operation, like: loop() { if (parity) { scrub_parity_stripe(); continue; } check_cancel_and_pause() scrub_normal_stripe(); } Reason is when introduce raid56 stripe scrub, new code is inserted simplely to front of loop. Better to: loop() { check_cancel_and_pause() if (parity) scrub_parity_stripe(); else scrub_normal_stripe(); } This patch adjusted code place to realize above sequence. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Show detail information when mount failed on missing devicesZhao Lei
When mount failed because missing device, we can see following dmesg: [ 1060.267743] BTRFS: too many missing devices, writeable mount is not allowed [ 1060.273158] BTRFS: open_ctree failed This patch add missing_device_number and tolerated_missing_device_number to above output, to let user know what really happened, and helps bug-report and debug. dmesg after patch: [ 127.050367] BTRFS: missing devices(1) exceeds the limit(0), writeable mount is not allowed [ 127.056099] BTRFS: open_ctree failed Changelog v1->v2: 1: Changed to more clear description, suggested-by: Anand Jain <anand.jain@oracle.com> Suggested-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09btrfs: Fix scrub panic when leaf crosses stripesZhao Lei
Scrub panic in following operation: mkfs.ext4 /dev/vdh btrfs-convert /dev/vdh mount /dev/vdh /mnt/tmp1 btrfs scrub start -B /dev/vdh (panic) Reason: 1: In some case, leaf created by btrfs-convert was splited into 2 strips. 2: Scrub bypassed part of above wrong leaf data, but remain data caused panic in scrub_checksum_tree_block(). For reason 1: we can get following information after some simple operation. a. mkfs.ext4 /dev/vdh btrfs-convert /dev/vdh b. btrfs-debug-tree /dev/vdh we can see following item in extent tree: item 25 key (27054080 METADATA_ITEM 0) itemoff 15083 itemsize 33 Its logical address is [27054080, 27070464) and acrossed 2 strips: [27000832, 27066368) [27066368, 27131904) Will be fixed in btrfs-progs(btrfs-convert, btrfsck, ...) For reason 2: Scrub is trying to do a "bypass" in this case, but the result is "panic", because current code lacks of some condition in bypass, and let some wrong leaf data escaped. This patch fixed above scrub code. Before patch: # btrfs scrub start -B /dev/vdh (panic) After patch: # btrfs scrub start -B /dev/vdh scrub done for 353cec8f-da31-4a94-aa35-be72d997b06e ... # dmesg ... [ 59.088697] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27000832 [ 59.089929] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27066368 # Reported-by: Chris Murphy <lists@colorremedies.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 search key advancing conditionNaohiro Aota
The search key advancing condition used in copy_to_sk() is loose. It can advance the key even if it reaches sk->max_*: e.g. when the max key = (512, 1024, -1) and the current key = (512, 1025, 10), it increments the offset by 1, continues hopeless search from (512, 1025, 11). This issue make ioctl() to take unexpectedly long time scanning all the leaf a blocks one by one. This commit fix the problem using standard way of key comparison: btrfs_comp_cpu_keys() Signed-off-by: Naohiro Aota <naota@elisp.net> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: teach backref walking about backrefs with underflowed offset valuesFilipe Manana
When cloning/deduplicating file extents (through the clone and extent_same ioctls) we can get data back references with offset values that are a result of an unsigned integer arithmetic underflow, that is, values that are much larger then they could be otherwise. This is not a problem when decrementing or dropping the back references (happens when we overwrite the extents or punch a hole for example, through __btrfs_drop_extents()), since we compute the same too large offset value, but it is a problem for the backref walking code, used by an incremental send and the ioctls that are used by the btrfs tool "inspect-internal" commands, as it makes it miss the corresponding file extent items because the search key is set for an extent item that starts at an offset matching the exceptionally large offset value of the data back reference. For an incremental send this causes the send ioctl to fail with -EIO. So teach the backref walking code to deal with these cases by setting the search key's offset to 0 if the backref's offset value is larger than LLONG_MAX (the largest possible file offset). This makes sure the backref walking code finds the corresponding file extent items at the expense of scanning more items and leafs in the btree. Fixing the clone/dedup ioctls to not produce such underflowed results would require major changes breaking backward compatibility, updating user space tools, etc. Simple reproducer case for fstests: 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() { rm -fr $send_files_dir rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_cloner _need_to_be_root send_files_dir=$TEST_DIR/btrfs-test-$seq rm -f $seqres.full rm -fr $send_files_dir mkdir $send_files_dir _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount # Create our test file with a single extent of 64K starting at file # offset 128K. $XFS_IO_PROG -f -c "pwrite -S 0xaa 128K 64K" $SCRATCH_MNT/foo \ | _filter_xfs_io _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \ $SCRATCH_MNT/mysnap1 # Now clone parts of the original extent into lower offsets of the file. # # The first clone operation adds a file extent item to file offset 0 # that points to our initial extent with a data offset of 16K. The # corresponding data back reference in the extent tree has an offset of # 18446744073709535232, which is the result of file_offset - data_offset # = 0 - 16K. # # The second clone operation adds a file extent item to file offset 16K # that points to our initial extent with a data offset of 48K. The # corresponding data back reference in the extent tree has an offset of # 18446744073709518848, which is the result of file_offset - data_offset # = 16K - 48K. # # Those large back reference offsets (result of unsigned arithmetic # underflow) confused the back reference walking code (used by an # incremental send and the multiple inspect-internal ioctls) and made it # miss the back references, which for the case of an incremental send it # made it fail with -EIO and print a message like the following to # dmesg: # # "BTRFS error (device sdc): did not find backref in send_root. \ # inode=257, offset=0, disk_byte=12845056 found extent=12845056" # $CLONER_PROG -s $(((128 + 16) * 1024)) -d 0 -l $((16 * 1024)) \ $SCRATCH_MNT/foo $SCRATCH_MNT/foo $CLONER_PROG -s $(((128 + 48) * 1024)) -d $((16 * 1024)) \ -l $((16 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \ $SCRATCH_MNT/mysnap2 _run_btrfs_util_prog send $SCRATCH_MNT/mysnap1 -f $send_files_dir/1.snap _run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \ -f $send_files_dir/2.snap echo "File digest in the original filesystem:" md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch # Now recreate the filesystem by receiving both send streams and verify # we get the same file contents that the original filesystem had. _scratch_unmount _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount _run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap _run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/2.snap echo "File digest in the new filesystem:" md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch status=0 exit The test's expected golden output is: wrote 65536/65536 bytes at offset 131072 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File digest in the original filesystem: 6c6079335cff141b8a31233ead04cbff SCRATCH_MNT/mysnap2/foo File digest in the new filesystem: 6c6079335cff141b8a31233ead04cbff SCRATCH_MNT/mysnap2/foo But it failed with: (...) @@ -1,7 +1,5 @@ QA output created by 097 wrote 65536/65536 bytes at offset 131072 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -File digest in the original filesystem: -6c6079335cff141b8a31233ead04cbff SCRATCH_MNT/mysnap2/foo -File digest in the new filesystem: -6c6079335cff141b8a31233ead04cbff SCRATCH_MNT/mysnap2/foo ... $ cat /home/fdmanana/git/hub/xfstests/results//btrfs/097.full (...) ERROR: send ioctl failed with -5: Input/output error Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-09Btrfs: fix stale dir entries after unlink, inode eviction and fsyncFilipe Manana
If we remove a hard link from an inode, the inode gets evicted, then we fsync the inode and then power fail/crash, when the log tree is replayed, the parent directory inode still has entries pointing to the name that no longer exists, while our inode no longer has the BTRFS_INODE_REF_KEY item matching the deleted hard link (as expected), leaving the filesystem in an inconsistent state. The stale directory entries can not be deleted (an attempt to delete them causes -ESTALE errors), which makes it impossible to delete the parent directory. This happens because we track the id of the transaction where the last unlink operation for the inode happened (last_unlink_trans) in an in-memory only field of the inode, that is, a value that is never persisted in the inode item stored on the fs/subvol btree. So if an inode is evicted and loaded again, the value for last_unlink_trans is set to 0, which prevents the fsync from logging the parent directory at btrfs_log_inode_parent(). So fix this by setting last_unlink_trans to the id of the transaction that last modified the inode when we load the inode. This is a pessimistic approach but it always ensures correctness with the trade off of ocassional full transaction commits when an fsync is done against the inode in the same transaction where it was evicted and reloaded when our inode is a directory and often logging its parent unnecessarily when our inode is not a directory. The following test case for fstests triggers the problem: 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 file with 2 hard links. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Now remove one of the links, trigger inode eviction and then fsync # our inode. unlink $SCRATCH_MNT/testdir/bar echo 2 > /proc/sys/vm/drop_caches $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/foo # Silently drop all writes on our scratch device to simulate a 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 our directory entries. echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir # If we remove our inode, its parent should become empty and therefore we should # be able to remove the parent. 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 failed on btrfs with: generic/098 4s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/098.out.bad) --- tests/generic/098.out 2015-07-23 18:01:12.616175932 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/098.out.bad 2015-07-23 18:04:58.924138308 +0100 @@ -1,3 +1,6 @@ QA output created by 098 Entries in testdir: +bar foo +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... (Run 'diff -u tests/generic/098.out /home/fdmanana/git/hub/xfstests/results//generic/098.out.bad' to see the entire diff) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent (see /home/fdmanana/git/hub/xfstests/results//generic/098.full) $ cat /home/fdmanana/git/hub/xfstests/results//generic/098.full (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 0 namelen 3 name foo filetype 1 errors 6, no dir index, no inode ref unresolved ref dir 257 index 3 namelen 3 name bar filetype 1 errors 5, no dir item, no inode ref Checking filesystem on /dev/sdc (...) 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>
2015-08-09Merge branch 'for-linus-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fix from Chris Mason: "We have a btrfs quota regression fix. I merged this one on Thursday and have run it through tests against current master. Normally I wouldn't have sent this while you were finalizing rc6, but I'm feeding mosquitoes in the adirondacks next week, so I wanted to get this one out before leaving. I'll leave longer tests running and check on things during the week, but I don't expect any problems" * 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: qgroup: Fix a regression in qgroup reserved space.
2015-08-07Btrfs: Spelling s/consitent/consistent/Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Jiri Kosina <jkosina@suse.com>
2015-08-06btrfs: qgroup: Fix a regression in qgroup reserved space.Qu Wenruo
During the change to new btrfs extent-oriented qgroup implement, due to it doesn't use the old __qgroup_excl_accounting() for exclusive extent, it didn't free the reserved bytes. The bug will cause limit function go crazy as the reserved space is never freed, increasing limit will have no effect and still cause EQOUT. The fix is easy, just free reserved bytes for newly created exclusive extent as what it does before. Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Yang Dongsheng <yangds.fnst@cn.fujitsu.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05char: make misc_deregister a void functionGreg Kroah-Hartman
With well over 200+ users of this api, there are a mere 12 users that actually checked the return value of this function. And all of them really didn't do anything with that information as the system or module was shutting down no matter what. So stop pretending like it matters, and just return void from misc_deregister(). If something goes wrong in the call, you will get a WARNING splat in the syslog so you know how to fix up your driver. Other than that, there's nothing that can go wrong. Cc: Alasdair Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Christine Caulfield <ccaulfie@redhat.com> Cc: David Teigland <teigland@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Acked-by: Joel Becker <jlbec@evilplan.org> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-31Merge branch 'for-linus-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Filipe fixed up a hard to trigger ENOSPC regression from our merge window pull, and we have a few other smaller fixes" * 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix quick exhaustion of the system array in the superblock btrfs: its btrfs_err() instead of btrfs_error() btrfs: Avoid NULL pointer dereference of free_extent_buffer when read_tree_block() fail btrfs: Fix lockdep warning of btrfs_run_delayed_iputs()
2015-07-29btrfs: add missing discards when unpinning extents with -o discardJeff Mahoney
When we clear the dirty bits in btrfs_delete_unused_bgs for extents in the empty block group, it results in btrfs_finish_extent_commit being unable to discard the freed extents. The block group removal patch added an alternate path to forget extents other than btrfs_finish_extent_commit. As a result, any extents that would be freed when the block group is removed aren't discarded. In my test run, with a large copy of mixed sized files followed by removal, it left nearly 2/3 of extents undiscarded. To clean up the block groups, we add the removed block group onto a list that will be discarded after transaction commit. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29btrfs: explictly delete unused block groups in close_ctree and ro-remountJeff Mahoney
The cleaner thread may already be sleeping by the time we enter close_ctree. If that's the case, we'll skip removing any unused block groups queued for removal, even during a normal umount. They'll be cleaned up automatically at next mount, but users expect a umount to be a clean synchronization point, especially when used on thin-provisioned storage with -odiscard. We also explicitly remove unused block groups in the ro-remount path for the same reason. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29btrfs: iterate over unused chunk space in FITRIMJeff Mahoney
Since we now clean up block groups automatically as they become empty, iterating over block groups is no longer sufficient to discard unused space. This patch iterates over the unused chunk space and discards any regions that are unallocated, regardless of whether they were ever used. This is a change for btrfs but is consistent with other file systems. We do this in a transactionless manner since the discard process can take a substantial amount of time and a transaction would need to be started before the acquisition of the device list lock. That would mean a transaction would be held open across /all/ of the discards collectively. In order to prevent other threads from allocating or freeing chunks, we hold the chunks lock across the search and discard calls. We release it between searches to allow the file system to perform more-or-less normally. Since the running transaction can commit and disappear while we're using the transaction pointer, we take a reference to it and release it after the search. This is safe since it would happen normally at the end of the transaction commit after any locks are released anyway. We also take the commit_root_sem to protect against a transaction starting and committing while we're running. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29btrfs: skip superblocks during discardJeff Mahoney
Btrfs doesn't track superblocks with extent records so there is nothing persistent on-disk to indicate that those blocks are in use. We track the superblocks in memory to ensure they don't get used by removing them from the free space cache when we load a block group from disk. Prior to 47ab2a6c6a (Btrfs: remove empty block groups automatically), that was fine since the block group would never be reclaimed so the superblock was always safe. Once we started removing the empty block groups, we were protected by the fact that discards weren't being properly issued for unused space either via FITRIM or -odiscard. The block groups were still being released, but the blocks remained on disk. In order to properly discard unused block groups, we need to filter out the superblocks from the discard range. Superblocks are located at fixed locations on each device, so it makes sense to filter them out in btrfs_issue_discard, which is used by both -odiscard and FITRIM. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29btrfs: btrfs_issue_discard ensure offset/length are aligned to sector boundariesJeff Mahoney
It's possible, though unexpected, to pass unaligned offsets and lengths to btrfs_issue_discard. We then shift the offset/length values to sector units. If an unaligned offset has been passed, it will result in the entire sector being discarded, possibly losing data. An unaligned length is safe but we'll end up returning an inaccurate number of discarded bytes. This patch aligns the offset to the 512B boundary, adjusts the length, and warns, since we shouldn't be discarding on an offset that isn't aligned with our sector size. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29btrfs: make btrfs_issue_discard return bytes discardedJeff Mahoney
Initially this will just be the length argument passed to it, but the following patches will adjust that to reflect re-alignment and skipped blocks. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-22Btrfs: fix quick exhaustion of the system array in the superblockFilipe Manana
Omar reported that after commit 4fbcdf669454 ("Btrfs: fix -ENOSPC when finishing block group creation"), introduced in 4.2-rc1, the following test was failing due to exhaustion of the system array in the superblock: #!/bin/bash truncate -s 100T big.img mkfs.btrfs big.img mount -o loop big.img /mnt/loop num=5 sz=10T for ((i = 0; i < $num; i++)); do echo fallocate $i $sz fallocate -l $sz /mnt/loop/testfile$i done btrfs filesystem sync /mnt/loop for ((i = 0; i < $num; i++)); do echo rm $i rm /mnt/loop/testfile$i btrfs filesystem sync /mnt/loop done umount /mnt/loop This made btrfs_add_system_chunk() fail with -EFBIG due to excessive allocation of system block groups. This happened because the test creates a large number of data block groups per transaction and when committing the transaction we start the writeout of the block group caches for all the new new (dirty) block groups, which results in pre-allocating space for each block group's free space cache using the same transaction handle. That in turn often leads to creation of more block groups, and all get attached to the new_bgs list of the same transaction handle to the point of getting a list with over 1500 elements, and creation of new block groups leads to the need of reserving space in the chunk block reserve and often creating a new system block group too. So that made us quickly exhaust the chunk block reserve/system space info, because as of the commit mentioned before, we do reserve space for each new block group in the chunk block reserve, unlike before where we would not and would at most allocate one new system block group and therefore would only ensure that there was enough space in the system space info to allocate 1 new block group even if we ended up allocating thousands of new block groups using the same transaction handle. That worked most of the time because the computed required space at check_system_chunk() is very pessimistic (assumes a chunk tree height of BTRFS_MAX_LEVEL/8 and that all nodes/leafs in a path will be COWed and split) and since the updates to the chunk tree all happen at btrfs_create_pending_block_groups it is unlikely that a path needs to be COWed more than once (unless writepages() for the btree inode is called by mm in between) and that compensated for the need of creating any new nodes/leads in the chunk tree. So fix this by ensuring we don't accumulate a too large list of new block groups in a transaction's handles new_bgs list, inserting/updating the chunk tree for all accumulated new block groups and releasing the unused space from the chunk block reserve whenever the list becomes sufficiently large. This is a generic solution even though the problem currently can only happen when starting the writeout of the free space caches for all dirty block groups (btrfs_start_dirty_block_groups()). Reported-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-22btrfs: its btrfs_err() instead of btrfs_error()Anand Jain
sorry I indented to use btrfs_err() and I have no idea how btrfs_error() got there. infact I was thinking about these kind of oversights since these two func are too closely named. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-22btrfs: Avoid NULL pointer dereference of free_extent_buffer when ↵Zhao Lei
read_tree_block() fail When read_tree_block() failed, we can see following dmesg: [ 134.371389] BUG: unable to handle kernel NULL pointer dereference at 0000000000000063 [ 134.372236] IP: [<ffffffff813a4a51>] free_extent_buffer+0x21/0x90 [ 134.372236] PGD 0 [ 134.372236] Oops: 0000 [#1] SMP [ 134.372236] Modules linked in: [ 134.372236] CPU: 0 PID: 2289 Comm: mount Not tainted 4.2.0-rc1_HEAD_c65b99f046843d2455aa231747b5a07a999a9f3d_+ #115 [ 134.372236] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 134.372236] task: ffff88003b6e1a00 ti: ffff880011e60000 task.ti: ffff880011e60000 [ 134.372236] RIP: 0010:[<ffffffff813a4a51>] [<ffffffff813a4a51>] free_extent_buffer+0x21/0x90 ... [ 134.372236] Call Trace: [ 134.372236] [<ffffffff81379aa1>] free_root_extent_buffers+0x91/0xb0 [ 134.372236] [<ffffffff81379c3d>] free_root_pointers+0x17d/0x190 [ 134.372236] [<ffffffff813801b0>] open_ctree+0x1ca0/0x25b0 [ 134.372236] [<ffffffff8144d017>] ? disk_name+0x97/0xb0 [ 134.372236] [<ffffffff813558aa>] btrfs_mount+0x8fa/0xab0 ... Reason: read_tree_block() changed to return error number on fail, and this value(not NULL) is set to tree_root->node, then subsequent code will run to: free_root_pointers() ->free_root_extent_buffers() ->free_extent_buffer() ->atomic_read((extent_buffer *)(-E_XXX)->refs); and trigger above error. Fix: Set tree_root->node to NULL on fail to make error_handle code happy. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>