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2015-03-02Btrfs: fix off-by-one logic error in btrfs_realloc_nodeFilipe Manana
The end_slot variable actually matches the number of pointers in the node and not the last slot (which is 'nritems - 1'). Therefore in order to check that the current slot in the for loop doesn't match the last one, the correct logic is to check if 'i' is less than 'end_slot - 1' and not 'end_slot - 2'. Fix this and set end_slot to be 'nritems - 1', as it's less confusing since the variable name implies it's inclusive rather then exclusive. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02Btrfs: add missing inode update when punching holeFilipe Manana
When punching a file hole if we endup only zeroing parts of a page, because the start offset isn't a multiple of the sector size or the start offset and length fall within the same page, we were not updating the inode item. This prevented an fsync from doing anything, if no other file changes happened in the current transaction, because the fields in btrfs_inode used to check if the inode needs to be fsync'ed weren't updated. This issue is easy to reproduce and the following excerpt from the xfstest case I made shows how to trigger it: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file. $XFS_IO_PROG -f -c "pwrite -S 0x22 -b 16K 0 16K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, this makes btrfs update some btrfs inode specific fields # that are used to track if the inode needs to be written/updated to the fsync # log or not. After this fsync, the new values for those fields indicate that # a subsequent fsync does not need to touch the fsync log. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Force a commit of the current transaction. After this point, any operation # that modifies the data or metadata of our file, should update those fields in # the btrfs inode with values that make the next fsync operation write to the # fsync log. sync # Punch a hole in our file. This small range affects only 1 page. # This made the btrfs hole punching implementation write only some zeroes in # one page, but it did not update the btrfs inode fields used to determine if # the next fsync needs to write to the fsync log. $XFS_IO_PROG -c "fpunch 8000 4K" $SCRATCH_MNT/foo # Another variation of the previously mentioned case. $XFS_IO_PROG -c "fpunch 15000 100" $SCRATCH_MNT/foo # Now fsync the file. This was a no-operation because the previous hole punch # operation didn't update the inode's fields mentioned before, so they remained # with the values they had after the first fsync - that is, they indicate that # it is not needed to write to fsync log. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Enable writes and mount the fs. This makes the fsync log replay code run. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Because the last fsync didn't do anything, here the file content matched what # it was after the first fsync, before the holes were punched, and not what it # was after the holes were punched. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This issue has been around since 2012, when the punch hole implementation was added, commit 2aaa66558172 ("Btrfs: add hole punching"). A test case for xfstests 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>
2015-03-02Btrfs: abort the transaction if we fail to update the free space cache inodeJosef Bacik
Our gluster boxes were hitting a problem where they'd run out of space when updating the block group cache and therefore wouldn't be able to update the free space inode. This is a problem because this is how we invalidate the cache and protect ourselves from errors further down the stack, so if this fails we have to abort the transaction so we make sure we don't end up with stale free space cache. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02Btrfs: fix fsync race leading to ordered extent memory leaksFilipe Manana
We can have multiple fsync operations against the same file during the same transaction and they can collect the same ordered extents while they don't complete (still accessible from the inode's ordered tree). If this happens, those ordered extents will never get their reference counts decremented to 0, leading to memory leaks and inode leaks (an iput for an ordered extent's inode is scheduled only when the ordered extent's refcount drops to 0). The following sequence diagram explains this race: CPU 1 CPU 2 btrfs_sync_file() btrfs_sync_file() mutex_lock(inode->i_mutex) btrfs_log_inode() btrfs_get_logged_extents() --> collects ordered extent X --> increments ordered extent X's refcount btrfs_submit_logged_extents() mutex_unlock(inode->i_mutex) mutex_lock(inode->i_mutex) btrfs_sync_log() btrfs_wait_logged_extents() --> list_del_init(&ordered->log_list) btrfs_log_inode() btrfs_get_logged_extents() --> Adds ordered extent X to logged_list because at this point: list_empty(&ordered->log_list) && test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags) == 0 --> Increments ordered extent X's refcount --> check if ordered extent's io is finished or not, start it if necessary and wait for it to finish --> sets bit BTRFS_ORDERED_LOGGED on ordered extent X's flags and adds it to trans->ordered btrfs_sync_log() finishes btrfs_submit_logged_extents() btrfs_log_inode() finishes mutex_unlock(inode->i_mutex) btrfs_sync_file() finishes btrfs_sync_log() btrfs_wait_logged_extents() --> Sees ordered extent X has the bit BTRFS_ORDERED_LOGGED set in its flags --> X's refcount is untouched btrfs_sync_log() finishes btrfs_sync_file() finishes btrfs_commit_transaction() --> called by transaction kthread for e.g. btrfs_wait_pending_ordered() --> waits for ordered extent X to complete --> decrements ordered extent X's refcount by 1 only, corresponding to the increment done by the fsync task ran by CPU 1 In the scenario of the above diagram, after the transaction commit, the ordered extent will remain with a refcount of 1 forever, leaking the ordered extent structure and preventing the i_count of its inode from ever decreasing to 0, since the delayed iput is scheduled only when the ordered extent's refcount drops to 0, preventing the inode from ever being evicted by the VFS. Fix this by using the flag BTRFS_ORDERED_LOGGED differently. Use it to mean that an ordered extent is already being processed by an fsync call, which will attach it to the current transaction, preventing it from being collected by subsequent fsync operations against the same inode. This race was introduced with the following change (added in 3.19 and backported to stable 3.18 and 3.17): Btrfs: make sure logged extents complete in the current transaction V3 commit 50d9aa99bd35c77200e0e3dd7a72274f8304701f I ran into this issue while running xfstests/generic/113 in a loop, which failed about 1 out of 10 runs with the following warning in dmesg: [ 2612.440038] WARNING: CPU: 4 PID: 22057 at fs/btrfs/disk-io.c:3558 free_fs_root+0x36/0x133 [btrfs]() [ 2612.442810] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop processor parport_pc parport psmouse therma l_sys i2c_piix4 serio_raw pcspkr evdev microcode button i2c_core ext4 crc16 jbd2 mbcache sd_mod sg sr_mod cdrom virtio_scsi ata_generic virtio_pci ata_piix virtio_ring libata virtio flo ppy e1000 scsi_mod [last unloaded: btrfs] [ 2612.452711] CPU: 4 PID: 22057 Comm: umount Tainted: G W 3.19.0-rc5-btrfs-next-4+ #1 [ 2612.454921] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 2612.457709] 0000000000000009 ffff8801342c3c78 ffffffff8142425e ffff88023ec8f2d8 [ 2612.459829] 0000000000000000 ffff8801342c3cb8 ffffffff81045308 ffff880046460000 [ 2612.461564] ffffffffa036da56 ffff88003d07b000 ffff880046460000 ffff880046460068 [ 2612.463163] Call Trace: [ 2612.463719] [<ffffffff8142425e>] dump_stack+0x4c/0x65 [ 2612.464789] [<ffffffff81045308>] warn_slowpath_common+0xa1/0xbb [ 2612.466026] [<ffffffffa036da56>] ? free_fs_root+0x36/0x133 [btrfs] [ 2612.467247] [<ffffffff810453c5>] warn_slowpath_null+0x1a/0x1c [ 2612.468416] [<ffffffffa036da56>] free_fs_root+0x36/0x133 [btrfs] [ 2612.469625] [<ffffffffa036f2a7>] btrfs_drop_and_free_fs_root+0x93/0x9b [btrfs] [ 2612.471251] [<ffffffffa036f353>] btrfs_free_fs_roots+0xa4/0xd6 [btrfs] [ 2612.472536] [<ffffffff8142612e>] ? wait_for_completion+0x24/0x26 [ 2612.473742] [<ffffffffa0370bbc>] close_ctree+0x1f3/0x33c [btrfs] [ 2612.475477] [<ffffffff81059d1d>] ? destroy_workqueue+0x148/0x1ba [ 2612.476695] [<ffffffffa034e3da>] btrfs_put_super+0x19/0x1b [btrfs] [ 2612.477911] [<ffffffff81153e53>] generic_shutdown_super+0x73/0xef [ 2612.479106] [<ffffffff811540e2>] kill_anon_super+0x13/0x1e [ 2612.480226] [<ffffffffa034e1e3>] btrfs_kill_super+0x17/0x23 [btrfs] [ 2612.481471] [<ffffffff81154307>] deactivate_locked_super+0x3b/0x50 [ 2612.482686] [<ffffffff811547a7>] deactivate_super+0x3f/0x43 [ 2612.483791] [<ffffffff8116b3ed>] cleanup_mnt+0x59/0x78 [ 2612.484842] [<ffffffff8116b44c>] __cleanup_mnt+0x12/0x14 [ 2612.485900] [<ffffffff8105d019>] task_work_run+0x8f/0xbc [ 2612.486960] [<ffffffff810028d8>] do_notify_resume+0x5a/0x6b [ 2612.488083] [<ffffffff81236e5b>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 2612.489333] [<ffffffff8142a17f>] int_signal+0x12/0x17 [ 2612.490353] ---[ end trace 54a960a6bdcb8d93 ]--- [ 2612.557253] VFS: Busy inodes after unmount of sdb. Self-destruct in 5 seconds. Have a nice day... Kmemleak confirmed the ordered extent leak (and btrfs inode specific structures such as delayed nodes): $ cat /sys/kernel/debug/kmemleak unreferenced object 0xffff880154290db0 (size 576): comm "btrfsck", pid 21980, jiffies 4295542503 (age 1273.412s) hex dump (first 32 bytes): 01 40 00 00 01 00 00 00 b0 1d f1 4e 01 88 ff ff .@.........N.... 00 00 00 00 00 00 00 00 c8 0d 29 54 01 88 ff ff ..........)T.... backtrace: [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83 [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190 [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs] [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs] [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs] [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs] [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff88014ef11db0 (size 576): comm "rm", pid 22009, jiffies 4295542593 (age 1273.052s) hex dump (first 32 bytes): 02 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 c8 1d f1 4e 01 88 ff ff ...........N.... backtrace: [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83 [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190 [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs] [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs] [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs] [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs] [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff8800336feda8 (size 584): comm "aio-stress", pid 22031, jiffies 4295543006 (age 1271.400s) hex dump (first 32 bytes): 00 40 3e 00 00 00 00 00 00 00 8f 42 00 00 00 00 .@>........B.... 00 00 01 00 00 00 00 00 00 00 01 00 00 00 00 00 ................ backtrace: [<ffffffff8114eb34>] create_object+0x172/0x29a [<ffffffff8141d790>] kmemleak_alloc+0x25/0x41 [<ffffffff81141ae6>] kmemleak_alloc_recursive.constprop.52+0x16/0x18 [<ffffffff81145288>] kmem_cache_alloc+0xf7/0x198 [<ffffffffa0389243>] __btrfs_add_ordered_extent+0x43/0x309 [btrfs] [<ffffffffa038968b>] btrfs_add_ordered_extent_dio+0x12/0x14 [btrfs] [<ffffffffa03810e2>] btrfs_get_blocks_direct+0x3ef/0x571 [btrfs] [<ffffffff81181349>] do_blockdev_direct_IO+0x62a/0xb47 [<ffffffff8118189a>] __blockdev_direct_IO+0x34/0x36 [<ffffffffa03776e5>] btrfs_direct_IO+0x16a/0x1e8 [btrfs] [<ffffffff81100373>] generic_file_direct_write+0xb8/0x12d [<ffffffffa038615c>] btrfs_file_write_iter+0x24b/0x42f [btrfs] [<ffffffff8118bb0d>] aio_run_iocb+0x2b7/0x32e [<ffffffff8118c99a>] do_io_submit+0x26e/0x2ff [<ffffffff8118ca3b>] SyS_io_submit+0x10/0x12 [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 CC: <stable@vger.kernel.org> # 3.19, 3.18 and 3.17 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-20Btrfs: fix allocation size calculations in alloc_btrfs_bioChris Mason
Since commit 8e5cfb55d3f (Btrfs: Make raid_map array be inlined in btrfs_bio structure), the raid map array is allocated along with the btrfs bio in alloc_btrfs_bio. The calculation used to decide how much we need to allocate was using the wrong parameter passed into the allocation function. The passed in real_stripes will be zero if a target replace operation is not currently running. We want to use total_stripes instead. Signed-off-by: Chris Mason <clm@fb.com> Reported-by: David Sterba <dsterba@suse.cz> Tested-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 BUG_ON in btrfs_orphan_add() when delete unused block groupForrest Liu
Removing large amount of block group in a transaction may encounters BUG_ON() in btrfs_orphan_add(). That is because btrfs_orphan_reserve_metadata() will grab metadata reservation from transaction handle, and btrfs_delete_unused_bgs() didn't reserve metadata for trnasaction handle when delete unused block group. The problem can be reproduce by following script mntpath=/btrfs loopdev=/dev/loop0 filepath=/home/forrest/image umount $mntpath losetup -d $loopdev truncate --size 1000g $filepath losetup $loopdev $filepath mkfs.btrfs -f $loopdev mount $loopdev $mntpath for j in `seq 1 1 1000`; do fallocate -l 1g $mntpath/$j done # wait cleaner thread remove unused block group sleep 300 The call trace that results from the BUG_ON() is: [ 613.093084] ------------[ cut here ]------------ [ 613.097928] kernel BUG at fs/btrfs/inode.c:3142! [ 613.105855] invalid opcode: 0000 [#1] SMP [ 613.112702] Modules linked in: coretemp(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) snd_ens1371(E) snd_ac97_codec(E) aes_x86_64(E) lrw(E) gf128mul(E) glue_helper(E) ppdev(E) ac97_bus(E) ablk_helper(E) gameport(E) cryptd(E) snd_rawmidi(E) snd_seq_device(E) snd_pcm(E) vmw_balloon(E) snd_timer(E) snd(E) soundcore(E) serio_raw(E) vmwgfx(E) ttm(E) drm_kms_helper(E) drm(E) vmw_vmci(E) parport_pc(E) shpchp(E) i2c_piix4(E) mac_hid(E) lp(E) parport(E) btrfs(E) xor(E) raid6_pq(E) hid_generic(E) usbhid(E) hid(E) psmouse(E) ahci(E) libahci(E) e1000(E) mptspi(E) mptscsih(E) mptbase(E) floppy(E) vmw_pvscsi(E) vmxnet3(E) [ 613.144196] CPU: 0 PID: 1480 Comm: btrfs-cleaner Tainted: G E 3.19.0-rc7-custom #2 [ 613.148501] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 [ 613.152694] task: ffff880035cdb1a0 ti: ffff880039cf4000 task.ti: ffff880039cf4000 [ 613.154969] RIP: 0010:[<ffffffffa01441c2>] [<ffffffffa01441c2>] btrfs_orphan_add+0x1d2/0x1e0 [btrfs] [ 613.157780] RSP: 0018:ffff880039cf7c48 EFLAGS: 00010286 [ 613.159560] RAX: 00000000ffffffe4 RBX: ffff88003bd981a0 RCX: ffff88003c9e4000 [ 613.161904] RDX: 0000000000002244 RSI: 0000000000040000 RDI: ffff88003c9e4138 [ 613.164264] RBP: ffff880039cf7c88 R08: 000060ffc0000850 R09: 0000000000000000 [ 613.166507] R10: ffff88003bc4b7a0 R11: ffffea0000eb6740 R12: ffff88003c9c0000 [ 613.168681] R13: ffff88003c102160 R14: ffff88003c9c0458 R15: 0000000000000001 [ 613.170932] FS: 0000000000000000(0000) GS:ffff88003f600000(0000) knlGS:0000000000000000 [ 613.173316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 613.175227] CR2: 00007f6343537000 CR3: 0000000036329000 CR4: 00000000000407f0 [ 613.177554] Stack: [ 613.178712] ffff880039cf7c88 ffffffffa0182a54 ffff88003c9e4b04 ffff88003c9c7800 [ 613.181297] ffff88003bc4b7a0 ffff88003bd981a0 ffff88003c8db200 ffff88003c2fcc60 [ 613.183782] ffff880039cf7d18 ffffffffa012da97 ffff88003bc4b7a4 ffff88003bc4b7a0 [ 613.186171] Call Trace: [ 613.187493] [<ffffffffa0182a54>] ? lookup_free_space_inode+0x44/0x100 [btrfs] [ 613.189801] [<ffffffffa012da97>] btrfs_remove_block_group+0x137/0x740 [btrfs] [ 613.192126] [<ffffffffa0166912>] btrfs_remove_chunk+0x672/0x780 [btrfs] [ 613.194267] [<ffffffffa012e2ff>] btrfs_delete_unused_bgs+0x25f/0x280 [btrfs] [ 613.196567] [<ffffffffa0135e4c>] cleaner_kthread+0x12c/0x190 [btrfs] [ 613.198687] [<ffffffffa0135d20>] ? check_leaf+0x350/0x350 [btrfs] [ 613.200758] [<ffffffff8108f232>] kthread+0xd2/0xf0 [ 613.202616] [<ffffffff8108f160>] ? kthread_create_on_node+0x180/0x180 [ 613.204738] [<ffffffff8175dabc>] ret_from_fork+0x7c/0xb0 [ 613.206652] [<ffffffff8108f160>] ? kthread_create_on_node+0x180/0x180 [ 613.208741] Code: ff ff 0f 1f 80 00 00 00 00 89 45 c8 3e 80 63 80 fd 48 89 df e8 d0 23 fe ff 8b 45 c8 e9 14 ff ff ff b8 f4 ff ff ff e9 12 ff ff ff <0f> 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 [ 613.216562] RIP [<ffffffffa01441c2>] btrfs_orphan_add+0x1d2/0x1e0 [btrfs] [ 613.218828] RSP <ffff880039cf7c48> [ 613.220382] ---[ end trace 71073106deb8a457 ]--- This patch replace btrfs_join_transaction() with btrfs_start_transaction() in btrfs_delete_unused_bgs() to revent BUG_ON() in btrfs_orphan_add() Signed-off-by: Forrest Liu <forrestl@synology.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: account for large extents with enospcJosef Bacik
On our gluster boxes we stream large tar balls of backups onto our fses. With 160gb of ram this means we get really large contiguous ranges of dirty data, but the way our ENOSPC stuff works is that as long as it's contiguous we only hold metadata reservation for one extent. The problem is we limit our extents to 128mb, so we'll end up with at least 800 extents so our enospc accounting is quite a bit lower than what we need. To keep track of this make sure we increase outstanding_extents for every multiple of the max extent size so we can be sure to have enough reserved metadata space. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: don't set and clear delalloc for O_DIRECT writesJosef Bacik
We do this to get the space accounting, but this is just needless churn on the io_tree, so just drop setting/clearing delalloc and just drop the reserved data space when we have a successfull allocation. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: only adjust outstanding_extents when we do a short writeJosef Bacik
We have this weird dance where we always inc outstanding_extents when we do a O_DIRECT write, even if we allocate the entire range. To get around this we also drop the metadata space if we successfully write. This is an unnecessary dance, we only need to jack up outstanding_extents if we don't satisfy the entire range request in get_blocks_direct, otherwise we are good using our original reservation. So drop the unconditional inc and the drop of the metadata space that we have for the unconditional inc. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14btrfs: Fix out-of-space bugZhao Lei
Btrfs will report NO_SPACE when we create and remove files for several times, and we can't write to filesystem until mount it again. Steps to reproduce: 1: Create a single-dev btrfs fs with default option 2: Write a file into it to take up most fs space 3: Delete above file 4: Wait about 100s to let chunk removed 5: goto 2 Script is like following: #!/bin/bash # Recommend 1.2G space, too large disk will make test slow DEV="/dev/sda16" MNT="/mnt/tmp" dev_size="$(lsblk -bn -o SIZE "$DEV")" || exit 2 file_size_m=$((dev_size * 75 / 100 / 1024 / 1024)) echo "Loop write ${file_size_m}M file on $((dev_size / 1024 / 1024))M dev" for ((i = 0; i < 10; i++)); do umount "$MNT" 2>/dev/null; done echo "mkfs $DEV" mkfs.btrfs -f "$DEV" >/dev/null || exit 2 echo "mount $DEV $MNT" mount "$DEV" "$MNT" || exit 2 for ((loop_i = 0; loop_i < 20; loop_i++)); do echo echo "loop $loop_i" echo "dd file..." cmd=(dd if=/dev/zero of="$MNT"/file0 bs=1M count="$file_size_m") "${cmd[@]}" 2>/dev/null || { # NO_SPACE error triggered echo "dd failed: ${cmd[*]}" exit 1 } echo "rm file..." rm -f "$MNT"/file0 || exit 2 for ((i = 0; i < 10; i++)); do df "$MNT" | tail -1 sleep 10 done done Reason: It is triggered by commit: 47ab2a6c689913db23ccae38349714edf8365e0a which is used to remove empty block groups automatically, but the reason is not in that patch. Code before works well because btrfs don't need to create and delete chunks so many times with high complexity. Above bug is caused by many reason, any of them can trigger it. Reason1: When we remove some continuous chunks but leave other chunks after, these disk space should be used by chunk-recreating, but in current code, only first create will successed. Fixed by Forrest Liu <forrestl@synology.com> in: Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole Reason2: contains_pending_extent() return wrong value in calculation. Fixed by Forrest Liu <forrestl@synology.com> in: Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole Reason3: btrfs_check_data_free_space() try to commit transaction and retry allocating chunk when the first allocating failed, but space_info->full is set in first allocating, and prevent second allocating in retry. Fixed in this patch by clear space_info->full in commit transaction. Tested for severial times by above script. Changelog v3->v4: use light weight int instead of atomic_t to record have_remove_bgs in transaction, suggested by: Josef Bacik <jbacik@fb.com> Changelog v2->v3: v2 fixed the bug by adding more commit-transaction, but we only need to reclaim space when we are really have no space for new chunk, noticed by: Filipe David Manana <fdmanana@gmail.com> Actually, our code already have this type of commit-and-retry, we only need to make it working with removed-bgs. v3 fixed the bug with above way. Changelog v1->v2: v1 will introduce a new bug when delete and create chunk in same disk space in same transaction, noticed by: Filipe David Manana <fdmanana@gmail.com> V2 fix this bug by commit transaction after remove block grops. Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Suggested-by: Filipe David Manana <fdmanana@gmail.com> Suggested-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14Btrfs: scrub, fix sleep in atomic contextFilipe Manana
My previous patch "Btrfs: fix scrub race leading to use-after-free" introduced the possibility to sleep in an atomic context, which happens when the scrub_lock mutex is held at the time scrub_pending_bio_dec() is called - this function can be called under an atomic context. Chris ran into this in a debug kernel which gave the following trace: [ 1928.950319] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:621 [ 1928.967334] in_atomic(): 1, irqs_disabled(): 0, pid: 149670, name: fsstress [ 1928.981324] INFO: lockdep is turned off. [ 1928.989244] CPU: 24 PID: 149670 Comm: fsstress Tainted: G W 3.19.0-rc7-mason+ #41 [ 1929.006418] Hardware name: ZTSYSTEMS Echo Ridge T4 /A9DRPF-10D, BIOS 1.07 05/10/2012 [ 1929.022207] ffffffff81a22cf8 ffff881076e03b78 ffffffff816b8dd9 ffff881076e03b78 [ 1929.037267] ffff880d8e828710 ffff881076e03ba8 ffffffff810856c4 ffff881076e03bc8 [ 1929.052315] 0000000000000000 000000000000026d ffffffff81a22cf8 ffff881076e03bd8 [ 1929.067381] Call Trace: [ 1929.072344] <IRQ> [<ffffffff816b8dd9>] dump_stack+0x4f/0x6e [ 1929.083968] [<ffffffff810856c4>] ___might_sleep+0x174/0x230 [ 1929.095352] [<ffffffff810857d2>] __might_sleep+0x52/0x90 [ 1929.106223] [<ffffffff816bb68f>] mutex_lock_nested+0x2f/0x3b0 [ 1929.117951] [<ffffffff810ab37d>] ? trace_hardirqs_on+0xd/0x10 [ 1929.129708] [<ffffffffa05dc838>] scrub_pending_bio_dec+0x38/0x70 [btrfs] [ 1929.143370] [<ffffffffa05dd0e0>] scrub_parity_bio_endio+0x50/0x70 [btrfs] [ 1929.157191] [<ffffffff812fa603>] bio_endio+0x53/0xa0 [ 1929.167382] [<ffffffffa05f96bc>] rbio_orig_end_io+0x7c/0xa0 [btrfs] [ 1929.180161] [<ffffffffa05f97ba>] raid_write_parity_end_io+0x5a/0x80 [btrfs] [ 1929.194318] [<ffffffff812fa603>] bio_endio+0x53/0xa0 [ 1929.204496] [<ffffffff8130401b>] blk_update_request+0x1eb/0x450 [ 1929.216569] [<ffffffff81096e58>] ? trigger_load_balance+0x78/0x500 [ 1929.229176] [<ffffffff8144c74d>] scsi_end_request+0x3d/0x1f0 [ 1929.240740] [<ffffffff8144ccac>] scsi_io_completion+0xac/0x5b0 [ 1929.252654] [<ffffffff81441c50>] scsi_finish_command+0xf0/0x150 [ 1929.264725] [<ffffffff8144d317>] scsi_softirq_done+0x147/0x170 [ 1929.276635] [<ffffffff8130ace6>] blk_done_softirq+0x86/0xa0 [ 1929.288014] [<ffffffff8105d92e>] __do_softirq+0xde/0x600 [ 1929.298885] [<ffffffff8105df6d>] irq_exit+0xbd/0xd0 (...) Fix this by using a reference count on the scrub context structure instead of locking the scrub_lock mutex. 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>
2015-02-03btrfs: cleanup init for list in free-space-cacheGui Hecheng
o removed an unecessary INIT_LIST_HEAD after LIST_HEAD o merge a declare & INIT_LIST_HEAD pair into one LIST_HEAD Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: delete chunk allocation attemp when setting block group roShaohua Li
Below test will fail currently: mkfs.ext4 -F /dev/sda btrfs-convert /dev/sda mount /dev/sda /mnt btrfs device add -f /dev/sdb /mnt btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt The reason is there are some block groups with usage 0, but the whole disk hasn't free space to allocate new chunk, so we even can't set such block group readonly. This patch deletes the chunk allocation when setting block group ro. For META, we already have reserve. But for SYSTEM, we don't have, so the check_system_chunk is still required. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: clear bio reference after submit_one_bio()Naohiro Aota
After submit_one_bio(), `bio' can go away. However submit_extent_page() leave `bio' referable if submit_one_bio() failed (e.g. -ENOMEM on OOM). It will cause invalid paging request when submit_extent_page() is called next time. I reproduced ENOMEM case with the following script (need CONFIG_FAIL_PAGE_ALLOC, and CONFIG_FAULT_INJECTION_DEBUG_FS). #!/bin/bash dmesgout=dmesg.txt start=100000 end=300000 step=1000 # btrfs options device=/dev/vdb1 directory=/mnt/btrfs # fault-injection options percent=100 times=3 mkdir -p $directory || exit 1 mount -o compress $device $directory || exit 1 rm -f $directory/file || exit 1 dd if=/dev/zero of=$directory/file bs=1M count=512 || exit 1 for interval in `seq $start $step $end`; do dmesg -C echo 1 > /proc/sys/vm/drop_caches sync export FAILCMD_TYPE=fail_page_alloc ./failcmd.sh -p $percent -t $times -i $interval \ --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \ -- \ cat $directory/file > /dev/null dmesg > ${dmesgout} if grep -q BUG: ${dmesgout}; then cat ${dmesgout} exit 1 fi done umount $directory exit 0 Signed-off-by: Naohiro Aota <naota@elisp.net> Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03Btrfs: fix scrub race leading to use-after-freeFilipe Manana
While running a scrub on a kernel with CONFIG_DEBUG_PAGEALLOC=y, I got the following trace: [68127.807663] BUG: unable to handle kernel paging request at ffff8803f8947a50 [68127.807663] IP: [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122 [68127.807663] PGD 3003067 PUD 43e1f5067 PMD 43e030067 PTE 80000003f8947060 [68127.807663] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [68127.807663] 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 processor parpo [68127.807663] CPU: 2 PID: 3081 Comm: kworker/u8:5 Not tainted 3.18.0-rc6-btrfs-next-3+ #4 [68127.807663] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [68127.807663] Workqueue: btrfs-btrfs-scrub btrfs_scrub_helper [btrfs] [68127.807663] task: ffff880101fc5250 ti: ffff8803f097c000 task.ti: ffff8803f097c000 [68127.807663] RIP: 0010:[<ffffffff8107da31>] [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122 [68127.807663] RSP: 0018:ffff8803f097fbb8 EFLAGS: 00010093 [68127.807663] RAX: 0000000028dd386c RBX: ffff8803f8947a50 RCX: 0000000028dd3854 [68127.807663] RDX: 0000000000000018 RSI: 0000000000000002 RDI: 0000000000000001 [68127.807663] RBP: ffff8803f097fbd8 R08: 0000000000000004 R09: 0000000000000001 [68127.807663] R10: ffff880102620980 R11: ffff8801f3e8c900 R12: 000000000001d390 [68127.807663] R13: 00000000cabd13c8 R14: ffff8803f8947800 R15: ffff88037c574f00 [68127.807663] FS: 0000000000000000(0000) GS:ffff88043dd00000(0000) knlGS:0000000000000000 [68127.807663] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [68127.807663] CR2: ffff8803f8947a50 CR3: 00000000b6481000 CR4: 00000000000006e0 [68127.807663] Stack: [68127.807663] ffffffff823942a8 ffff8803f8947a50 ffff8802a3416f80 0000000000000000 [68127.807663] ffff8803f097fc18 ffffffff8141e7c0 ffffffff81072948 000000000034f314 [68127.807663] ffff8803f097fc08 0000000000000292 ffff8803f097fc48 ffff8803f8947a50 [68127.807663] Call Trace: [68127.807663] [<ffffffff8141e7c0>] _raw_spin_lock_irqsave+0x4b/0x55 [68127.807663] [<ffffffff81072948>] ? __wake_up+0x22/0x4b [68127.807663] [<ffffffff81072948>] __wake_up+0x22/0x4b [68127.807663] [<ffffffffa0392327>] scrub_pending_bio_dec+0x32/0x36 [btrfs] [68127.807663] [<ffffffffa0395e70>] scrub_bio_end_io_worker+0x5a3/0x5c9 [btrfs] [68127.807663] [<ffffffff810e0c7c>] ? time_hardirqs_off+0x15/0x28 [68127.807663] [<ffffffff81078106>] ? trace_hardirqs_off_caller+0x4c/0xb9 [68127.807663] [<ffffffffa0372a7c>] normal_work_helper+0xf1/0x238 [btrfs] [68127.807663] [<ffffffffa0372d3d>] btrfs_scrub_helper+0x12/0x14 [btrfs] [68127.807663] [<ffffffff810582d2>] process_one_work+0x1e4/0x3b6 [68127.807663] [<ffffffff81078180>] ? trace_hardirqs_off+0xd/0xf [68127.807663] [<ffffffff81058dc9>] worker_thread+0x1fb/0x2a8 [68127.807663] [<ffffffff81058bce>] ? rescuer_thread+0x219/0x219 [68127.807663] [<ffffffff8105cd75>] kthread+0xdb/0xe3 [68127.807663] [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67 [68127.807663] [<ffffffff8141f1ec>] ret_from_fork+0x7c/0xb0 [68127.807663] [<ffffffff8105cc9a>] ? __kthread_parkme+0x67/0x67 [68127.807663] Code: 39 c2 75 14 8d 8a 00 00 01 00 89 d0 f0 0f b1 0b 39 d0 0f 84 81 00 00 00 4c 69 2d 27 86 99 00 fa 00 00 00 45 31 e4 4d 39 ec 74 2b <8b> 13 89 d0 c1 e8 10 66 39 c2 75 [68127.807663] RIP [<ffffffff8107da31>] do_raw_spin_lock+0x94/0x122 [68127.807663] RSP <ffff8803f097fbb8> [68127.807663] CR2: ffff8803f8947a50 [68127.807663] ---[ end trace d7045aac00a66cd8 ]--- This is due to a race that can happen in a very tiny time window and is illustrated by the following sequence diagram: CPU 1 CPU 2 btrfs_scrub_dev() scrub_bio_end_io_worker() scrub_pending_bio_dec() atomic_dec(&sctx->bios_in_flight) wait sctx->bios_in_flight == 0 wait sctx->workers_pending == 0 mutex_lock(&fs_info->scrub_lock) (...) mutex_lock(&fs_info->scrub_lock) scrub_free_ctx(sctx) kfree(sctx) wake_up(&sctx->list_wait) __wake_up() spin_lock_irqsave(&sctx->list_wait->lock, flags) Another variation of this scenario that results in the same use-after-free issue is: CPU 1 CPU 2 btrfs_scrub_dev() wait sctx->bios_in_flight == 0 scrub_bio_end_io_worker() scrub_pending_bio_dec() __wake_up(&sctx->list_wait) spin_lock_irqsave(&sctx->list_wait->lock, flags) default_wake_function() wake up task at CPU 2 wait sctx->workers_pending == 0 mutex_lock(&fs_info->scrub_lock) (...) mutex_lock(&fs_info->scrub_lock) scrub_free_ctx(sctx) kfree(sctx) spin_unlock_irqrestore(&sctx->list_wait->lock, flags) Fix this by holding the scrub lock while doing the wakeup. This isn't a recent regression, the issue as been around since the scrub feature was added (2011, commit a2de733c78fa7af51ba9670482fa7d392aa67c57). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03Btrfs: add missing cleanup on sysfs init failureFilipe Manana
If we failed during initialization of sysfs, we weren't unregistering the top level btrfs sysfs entry nor the debugfs stuff. Not unregistering the top level sysfs entry makes future attempts to reload the btrfs module impossible and the following is reported in dmesg: [ 2246.451296] WARNING: CPU: 3 PID: 10999 at fs/sysfs/dir.c:486 sysfs_warn_dup+0x91/0xb0() [ 2246.451298] sysfs: cannot create duplicate filename '/fs/btrfs' [ 2246.451298] Modules linked in: btrfs(+) raid6_pq xor bnep rfcomm bluetooth binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc parport_pc parport psmouse serio_raw pcspkr evbug i2c_piix4 e1000 floppy [last unloaded: btrfs] [ 2246.451310] CPU: 3 PID: 10999 Comm: modprobe Tainted: G W 3.13.0-fdm-btrfs-next-24+ #7 [ 2246.451311] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 2246.451312] 0000000000000009 ffff8800d353fa08 ffffffff816f1da6 0000000000000410 [ 2246.451314] ffff8800d353fa58 ffff8800d353fa48 ffffffff8104a32c ffff88020821a290 [ 2246.451316] ffff88020821a290 ffff88020821a290 ffff8802148f0000 ffff8800d353fb80 [ 2246.451318] Call Trace: [ 2246.451322] [<ffffffff816f1da6>] dump_stack+0x4e/0x68 [ 2246.451324] [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0 [ 2246.451325] [<ffffffff8104a416>] warn_slowpath_fmt+0x46/0x50 [ 2246.451328] [<ffffffff81367dc5>] ? strlcat+0x65/0x90 (....) This fixes the following change: btrfs: add simple debugfs interface commit 1bae30982bc86ab66d61ccb6e22792593b45d44d Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03Btrfs: fix race between transaction commit and empty block group removalFilipe Manana
Committing a transaction can race with automatic removal of empty block groups (cleaner kthread), leading to a BUG_ON() in the transaction commit code while running btrfs_finish_extent_commit(). The following sequence diagram shows how it can happen: CPU 1 CPU 2 btrfs_commit_transaction() fs_info->running_transaction = NULL btrfs_finish_extent_commit() find_first_extent_bit() -> found range for block group X in fs_info->freed_extents[] btrfs_delete_unused_bgs() -> found block group X Removed block group X's range from fs_info->freed_extents[] btrfs_remove_chunk() btrfs_remove_block_group(bg X) unpin_extent_range(bg X range) btrfs_lookup_block_group(bg X) -> returns NULL -> BUG_ON() The trace that results from the BUG_ON() is: [48665.187808] ------------[ cut here ]------------ [48665.188032] kernel BUG at fs/btrfs/extent-tree.c:5675! [48665.188032] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [48665.188032] 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 evdev microcode [48665.197388] CPU: 2 PID: 31211 Comm: kworker/u32:16 Tainted: G W 3.19.0-rc5-btrfs-next-4+ #1 [48665.197388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [48665.197388] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] [48665.197388] task: ffff880222011810 ti: ffff8801b56a4000 task.ti: ffff8801b56a4000 [48665.197388] RIP: 0010:[<ffffffffa0350d05>] [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs] [48665.197388] RSP: 0018:ffff8801b56a7b88 EFLAGS: 00010246 [48665.197388] RAX: 0000000000000000 RBX: ffff8802143a6000 RCX: ffff8802220120c8 [48665.197388] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8800a3c140b0 [48665.197388] RBP: ffff8801b56a7bd8 R08: 0000000000000003 R09: 0000000000000000 [48665.197388] R10: 0000000000000000 R11: 000000000000bbac R12: 0000000012e8e000 [48665.197388] R13: ffff8800a3c14000 R14: 0000000000000000 R15: 0000000000000000 [48665.197388] FS: 0000000000000000(0000) GS:ffff88023ec40000(0000) knlGS:0000000000000000 [48665.197388] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [48665.197388] CR2: 00007f065e42f270 CR3: 0000000206f70000 CR4: 00000000000006e0 [48665.197388] Stack: [48665.197388] ffff8801b56a7bd8 0000000012ea0000 01ff8800a3c14138 0000000012e9ffff [48665.197388] ffff880141df3dd8 ffff8802143a6000 ffff8800a3c14138 ffff880141df3df0 [48665.197388] ffff880141df3dd8 0000000000000000 ffff8801b56a7c08 ffffffffa0354227 [48665.197388] Call Trace: [48665.197388] [<ffffffffa0354227>] btrfs_finish_extent_commit+0xb0/0xd9 [btrfs] [48665.197388] [<ffffffffa0366b4b>] btrfs_commit_transaction+0x791/0x92c [btrfs] [48665.197388] [<ffffffffa0352432>] flush_space+0x43d/0x452 [btrfs] [48665.197388] [<ffffffff814295c3>] ? _raw_spin_unlock+0x28/0x33 [48665.197388] [<ffffffffa035255f>] btrfs_async_reclaim_metadata_space+0x118/0x164 [btrfs] [48665.197388] [<ffffffff81059917>] ? process_one_work+0x14b/0x3ab [48665.197388] [<ffffffff810599ac>] process_one_work+0x1e0/0x3ab [48665.197388] [<ffffffff81079fa9>] ? trace_hardirqs_off+0xd/0xf [48665.197388] [<ffffffff8105a55b>] worker_thread+0x210/0x2d0 [48665.197388] [<ffffffff8105a34b>] ? rescuer_thread+0x2c3/0x2c3 [48665.197388] [<ffffffff8105e5c0>] kthread+0xef/0xf7 [48665.197388] [<ffffffff81429682>] ? _raw_spin_unlock_irq+0x2d/0x39 [48665.197388] [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad [48665.197388] [<ffffffff81429dec>] ret_from_fork+0x7c/0xb0 [48665.197388] [<ffffffff8105e4d1>] ? __kthread_parkme+0xad/0xad [48665.197388] Code: 85 f6 74 14 49 8b 06 49 03 46 09 49 39 c4 72 1d 4c 89 f7 e8 83 ec ff ff 4c 89 e6 4c 89 ef e8 1e f1 ff ff 48 85 c0 49 89 c6 75 02 <0f> 0b 49 8b 1e 49 03 5e 09 48 8b [48665.197388] RIP [<ffffffffa0350d05>] unpin_extent_range+0x6a/0x1ba [btrfs] [48665.197388] RSP <ffff8801b56a7b88> [48665.272246] ---[ end trace b9c6ab9957521376 ]--- Fix this by ensuring that unpining the block group's range in btrfs_finish_extent_commit() is done in a synchronized fashion with removing the block group's range from freed_extents[] in btrfs_delete_unused_bgs() This race got introduced with the change: Btrfs: remove empty block groups automatically commit 47ab2a6c689913db23ccae38349714edf8365e0a Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: add more checks to btrfs_read_sys_arrayDavid Sterba
Verify that the sys_array has enough bytes to read the next item. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: cleanup, rename a few variables in btrfs_read_sys_arrayDavid Sterba
There's a pointer to buffer, integer offset and offset passed as pointer, try to find matching names for them. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: add checks for sys_chunk_array sizesDavid Sterba
Verify that possible minimum and maximum size is set, validity of contents is checked in btrfs_read_sys_array. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesizeDavid Sterba
I received a few crafted images from Jiri, all got through the recently added superblock checks. The lower bounds checks for num_devices and sector/node -sizes were missing and caused a crash during mount. Tools for symbolic code execution were used to prepare the images contents. Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03Btrfs: Add code to support file creation timechandan r
This patch adds a new member to the 'struct btrfs_inode' structure to hold the file creation time. Signed-off-by: chandan <chandanrmail@gmail.com> [refreshed, removed btrfs_inode_otime] Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-03btrfs: 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>
2015-01-22Btrfs: insert_new_root: Fix lock type of the extent buffer.chandan
btrfs_alloc_tree_block() returns an extent buffer on which a blocked lock has been taken. Hence assign the appropriate value to path->locks[level]. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: fix unused members in struct btrfs_rootAnand Jain
There isn't any real use of following members of struct btrfs_root so delete them. struct kobject root_kobj; struct completion kobj_unregister; Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22btrfs: qgroup: move WARN_ON() to the correct location.Yang Dongsheng
In function qgroup_excl_accounting(), we need to WARN when qg->excl is less than what we want to free, same to child and parents. But currently, for parent qgroup, the WARN_ON() is located after freeing qg->excl. It will WARN out even we free it normally. This patch move this WARN_ON() before freeing qg->excl. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: cleanup unused run_mostLiu Bo
"run_most" is not used anymore. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Rename all ref_count to refs in structZhao Lei
refs is better than ref_count to record a struct's ref count. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Suggested-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Introduce BTRFS_BLOCK_GROUP_RAID56_MASK to check raid56 simplyZhao Lei
So we can check raid56 with: (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) instead of long: (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Include map_type in raid_bioZhao Lei
Corrent code use many kinds of "clever" way to determine operation target's raid type, as: raid_map != NULL or raid_map[MAX_NR] == RAID[56]_Q_STRIPE To make code easy to maintenance, this patch put raid type into bbio, and we can always get raid type from bbio with a "stupid" way. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Simplify scrub_setup_recheck_block()'s argumentZhao Lei
scrub_setup_recheck_block() have many arguments but most of them can be get from one of them, we can remove them to make code clean. Some other cleanup for that function also included in this patch. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Combine per-page recover in dev-replace and scrubZhao Lei
The code are similar, combine them to make code clean and easy to maintenance. Some lost condition are also completed with benefit of this combination. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Separate finding-right-mirror and writing-to-target's process in ↵Zhao Lei
scrub_handle_errored_block() In corrent code, code of finding-right-mirror and writing-to-target are mixed in logic, if we find a right mirror but failed in writing to target, it will treat as "hadn't found right block", and fill the target with sblock_bad. Actually, "failed in writing to target" does not mean "source block is wrong", this patch separate above two condition in logic, and do some cleanup to make code clean. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Break loop when reach BTRFS_MAX_MIRRORS in scrub_setup_recheck_block()Zhao Lei
Use break instead of useless loop should be more suitable in this case. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: btrfs_rm_dev_replace_blocked(): Use wait_event()Zhao Lei
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Cleanup btrfs_bio_counter_inc_blocked()Zhao Lei
1: Remove no-need DEFINE_WAIT(wait) 2: Add likely() for BTRFS_FS_STATE_DEV_REPLACING condition 3: Use while loop instead of goto Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Remove noneed force_write in scrub_write_block_to_dev_replaceZhao Lei
It is always 1 in this place, because !1 case was already jumped out in previous code. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Fix a jump typo of nodatasum_case to avoid wrong WARN_ON()Zhao Lei
if (sctx->is_dev_replace && !is_metadata && !have_csum) { ... goto nodatasum_case; } ... nodatasum_case: WARN_ON(sctx->is_dev_replace); In above code, nodatasum_case marker should be moved after WARN_ON(). Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: add ref_count and free function for btrfs_bioZhao Lei
1: ref_count is simple than current RBIO_HOLD_BBIO_MAP_BIT flag to keep btrfs_bio's memory in raid56 recovery implement. 2: free function for bbio will make code clean and flexible, plus forced data type checking in compile. Changelog v1->v2: Rename following by David Sterba's suggestion: put_btrfs_bio() -> btrfs_put_bio() get_btrfs_bio() -> btrfs_get_bio() bbio->ref_count -> bbio->refs Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Make raid_map array be inlined in btrfs_bio structureZhao Lei
It can make code more simple and clear, we need not care about free bbio and raid_map together. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: sort raid_map before adding tgtdev stripesZhao Lei
It can avoid complex calculation of real stripes in sort, moreover, we can clean up code of sorting tgtdev_map because it will be in order initially. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: fix a out-of-bound access of raid_mapZhao Lei
We add the number of stripes on target devices into bbio->num_stripes if we are under device replacement, and we just sort the raid_map of those stripes that not on the target devices, so if when we need real raid_map, we need skip the stripes on the target devices. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: 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>
2015-01-22Btrfs: 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>
2015-01-22Btrfs: 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>
2015-01-22Btrfs: lookup for block group only if needed when freeing a tree blockFilipe Manana
Very often our extent buffer's header generation doesn't match the current transaction's id or it is also referenced by other trees (snapshots), so we don't need the corresponding block group cache object. Therefore only search for it if we are going to use it, so we avoid an unnecessary search in the block groups rbtree (and acquiring and releasing its spinlock). Freeing a tree block is performed when COWing or deleting a node/leaf, which implies we are holding the node/leaf's parent node lock, therefore reducing the amount of time spent when freeing a tree block helps reducing the amount of time we are holding the parent node's lock. For example, for a run of xfstests/generic/083, the block group cache object was needed only 682 times for a total of 226691 calls to free a tree block. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22btrfs: remove a no-op unfreeze superbock callbackDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
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