1. 13 2月, 2019 2 次提交
    • E
      btrfs: use tagged writepage to mitigate livelock of snapshot · f5d5b543
      Ethan Lien 提交于
      [ Upstream commit 3cd24c698004d2f7668e0eb9fc1f096f533c791b ]
      
      Snapshot is expected to be fast. But if there are writers steadily
      creating dirty pages in our subvolume, the snapshot may take a very long
      time to complete. To fix the problem, we use tagged writepage for
      snapshot flusher as we do in the generic write_cache_pages(), so we can
      omit pages dirtied after the snapshot command.
      
      This does not change the semantics regarding which data get to the
      snapshot, if there are pages being dirtied during the snapshotting
      operation.  There's a sync called before snapshot is taken in old/new
      case, any IO in flight just after that may be in the snapshot but this
      depends on other system effects that might still sync the IO.
      
      We do a simple snapshot speed test on a Intel D-1531 box:
      
      fio --ioengine=libaio --iodepth=32 --bs=4k --rw=write --size=64G
      --direct=0 --thread=1 --numjobs=1 --time_based --runtime=120
      --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
      time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio
      
      original: 1m58sec
      patched:  6.54sec
      
      This is the best case for this patch since for a sequential write case,
      we omit nearly all pages dirtied after the snapshot command.
      
      For a multi writers, random write test:
      
      fio --ioengine=libaio --iodepth=32 --bs=4k --rw=randwrite --size=64G
      --direct=0 --thread=1 --numjobs=4 --time_based --runtime=120
      --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
      time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio
      
      original: 15.83sec
      patched:  10.35sec
      
      The improvement is smaller compared to the sequential write case,
      since we omit only half of the pages dirtied after snapshot command.
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NEthan Lien <ethanlien@synology.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      f5d5b543
    • A
      btrfs: harden agaist duplicate fsid on scanned devices · 3733632e
      Anand Jain 提交于
      [ Upstream commit a9261d4125c97ce8624e9941b75dee1b43ad5df9 ]
      
      It's not that impossible to imagine that a device OR a btrfs image is
      copied just by using the dd or the cp command. Which in case both the
      copies of the btrfs will have the same fsid. If on the system with
      automount enabled, the copied FS gets scanned.
      
      We have a known bug in btrfs, that we let the device path be changed
      after the device has been mounted. So using this loop hole the new
      copied device would appears as if its mounted immediately after it's
      been copied.
      
      For example:
      
      Initially.. /dev/mmcblk0p4 is mounted as /
      
        $ lsblk
        NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
        mmcblk0     179:0    0 29.2G  0 disk
        |-mmcblk0p4 179:4    0    4G  0 part /
        |-mmcblk0p2 179:2    0  500M  0 part /boot
        |-mmcblk0p3 179:3    0  256M  0 part [SWAP]
        `-mmcblk0p1 179:1    0  256M  0 part /boot/efi
      
        $ btrfs fi show
           Label: none  uuid: 07892354-ddaa-4443-90ea-f76a06accaba
           Total devices 1 FS bytes used 1.40GiB
           devid    1 size 4.00GiB used 3.00GiB path /dev/mmcblk0p4
      
      Copy mmcblk0 to sda
      
        $ dd if=/dev/mmcblk0 of=/dev/sda
      
      And immediately after the copy completes the change in the device
      superblock is notified which the automount scans using btrfs device scan
      and the new device sda becomes the mounted root device.
      
        $ lsblk
        NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
        sda           8:0    1 14.9G  0 disk
        |-sda4        8:4    1    4G  0 part /
        |-sda2        8:2    1  500M  0 part
        |-sda3        8:3    1  256M  0 part
        `-sda1        8:1    1  256M  0 part
        mmcblk0     179:0    0 29.2G  0 disk
        |-mmcblk0p4 179:4    0    4G  0 part
        |-mmcblk0p2 179:2    0  500M  0 part /boot
        |-mmcblk0p3 179:3    0  256M  0 part [SWAP]
        `-mmcblk0p1 179:1    0  256M  0 part /boot/efi
      
        $ btrfs fi show /
          Label: none  uuid: 07892354-ddaa-4443-90ea-f76a06accaba
          Total devices 1 FS bytes used 1.40GiB
          devid    1 size 4.00GiB used 3.00GiB path /dev/sda4
      
      The bug is quite nasty that you can't either unmount /dev/sda4 or
      /dev/mmcblk0p4. And the problem does not get solved until you take sda
      out of the system on to another system to change its fsid using the
      'btrfstune -u' command.
      Signed-off-by: NAnand Jain <anand.jain@oracle.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      3733632e
  2. 07 2月, 2019 2 次提交
    • E
      btrfs: On error always free subvol_name in btrfs_mount · 9ee5987f
      Eric W. Biederman 提交于
      commit 532b618bdf237250d6d4566536d4b6ce3d0a31fe upstream.
      
      The subvol_name is allocated in btrfs_parse_subvol_options and is
      consumed and freed in mount_subvol.  Add a free to the error paths that
      don't call mount_subvol so that it is guaranteed that subvol_name is
      freed when an error happens.
      
      Fixes: 312c89fb ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()")
      Cc: stable@vger.kernel.org # v4.19+
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9ee5987f
    • F
      Btrfs: fix deadlock when allocating tree block during leaf/node split · 5bce1436
      Filipe Manana 提交于
      commit a6279470762c19ba97e454f90798373dccdf6148 upstream.
      
      When splitting a leaf or node from one of the trees that are modified when
      flushing pending block groups (extent, chunk, device and free space trees),
      we need to allocate a new tree block, which in turn can result in the need
      to allocate a new block group. After allocating the new block group we may
      need to flush new block groups that were previously allocated during the
      course of the current transaction, which is what may cause a deadlock due
      to attempts to write lock twice the same leaf or node, as when splitting
      a leaf or node we are holding a write lock on it and its parent node.
      
      The same type of deadlock can also happen when increasing the tree's
      height, since we are holding a lock on the existing root while allocating
      the tree block to use as the new root node.
      
      An example trace when the deadlock happens during the leaf split path is:
      
        [27175.293054] CPU: 0 PID: 3005 Comm: kworker/u17:6 Tainted: G        W         4.19.16 #1
        [27175.293942] Hardware name: Penguin Computing Relion 1900/MD90-FS0-ZB-XX, BIOS R15 06/25/2018
        [27175.294846] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
        (...)
        [27175.298384] RSP: 0018:ffffab2087107758 EFLAGS: 00010246
        [27175.299269] RAX: 0000000000000bbd RBX: ffff9fadc7141c48 RCX: 0000000000000001
        [27175.300155] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9fadc7141c48
        [27175.301023] RBP: 0000000000000001 R08: ffff9faeb6ac1040 R09: ffff9fa9c0000000
        [27175.301887] R10: 0000000000000000 R11: 0000000000000040 R12: ffff9fb21aac8000
        [27175.302743] R13: ffff9fb1a64d6a20 R14: 0000000000000001 R15: ffff9fb1a64d6a18
        [27175.303601] FS:  0000000000000000(0000) GS:ffff9fb21fa00000(0000) knlGS:0000000000000000
        [27175.304468] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
        [27175.305339] CR2: 00007fdc8743ead8 CR3: 0000000763e0a006 CR4: 00000000003606f0
        [27175.306220] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
        [27175.307087] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
        [27175.307940] Call Trace:
        [27175.308802]  btrfs_search_slot+0x779/0x9a0 [btrfs]
        [27175.309669]  ? update_space_info+0xba/0xe0 [btrfs]
        [27175.310534]  btrfs_insert_empty_items+0x67/0xc0 [btrfs]
        [27175.311397]  btrfs_insert_item+0x60/0xd0 [btrfs]
        [27175.312253]  btrfs_create_pending_block_groups+0xee/0x210 [btrfs]
        [27175.313116]  do_chunk_alloc+0x25f/0x300 [btrfs]
        [27175.313984]  find_free_extent+0x706/0x10d0 [btrfs]
        [27175.314855]  btrfs_reserve_extent+0x9b/0x1d0 [btrfs]
        [27175.315707]  btrfs_alloc_tree_block+0x100/0x5b0 [btrfs]
        [27175.316548]  split_leaf+0x130/0x610 [btrfs]
        [27175.317390]  btrfs_search_slot+0x94d/0x9a0 [btrfs]
        [27175.318235]  btrfs_insert_empty_items+0x67/0xc0 [btrfs]
        [27175.319087]  alloc_reserved_file_extent+0x84/0x2c0 [btrfs]
        [27175.319938]  __btrfs_run_delayed_refs+0x596/0x1150 [btrfs]
        [27175.320792]  btrfs_run_delayed_refs+0xed/0x1b0 [btrfs]
        [27175.321643]  delayed_ref_async_start+0x81/0x90 [btrfs]
        [27175.322491]  normal_work_helper+0xd0/0x320 [btrfs]
        [27175.323328]  ? move_linked_works+0x6e/0xa0
        [27175.324160]  process_one_work+0x191/0x370
        [27175.324976]  worker_thread+0x4f/0x3b0
        [27175.325763]  kthread+0xf8/0x130
        [27175.326531]  ? rescuer_thread+0x320/0x320
        [27175.327284]  ? kthread_create_worker_on_cpu+0x50/0x50
        [27175.328027]  ret_from_fork+0x35/0x40
        [27175.328741] ---[ end trace 300a1b9f0ac30e26 ]---
      
      Fix this by preventing the flushing of new blocks groups when splitting a
      leaf/node and when inserting a new root node for one of the trees modified
      by the flushing operation, similar to what is done when COWing a node/leaf
      from on of these trees.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202383Reported-by: NEli V <eliventer@gmail.com>
      CC: stable@vger.kernel.org # 4.4+
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5bce1436
  3. 26 1月, 2019 4 次提交
    • J
      btrfs: improve error handling of btrfs_add_link · 310f8296
      Johannes Thumshirn 提交于
      [ Upstream commit 1690dd41e0cb1dade80850ed8a3eb0121b96d22f ]
      
      In the error handling block, err holds the return value of either
      btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked
      since it's introduction with commit fe66a05a (Btrfs: improve error
      handling for btrfs_insert_dir_item callers) in 2012.
      
      If the error handling in the error handling fails, there's not much left
      to do and the abort either happened earlier in the callees or is
      necessary here.
      
      So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort
      the transaction, but still return the original code of the failure
      stored in 'ret' as this will be reported to the user.
      Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      310f8296
    • A
      btrfs: fix use-after-free due to race between replace start and cancel · 38b17eee
      Anand Jain 提交于
      [ Upstream commit d189dd70e2556181732598956d808ea53cc8774e ]
      
      The device replace cancel thread can race with the replace start thread
      and if fs_info::scrubs_running is not yet set, btrfs_scrub_cancel() will
      fail to stop the scrub thread.
      
      The scrub thread continues with the scrub for replace which then will
      try to write to the target device and which is already freed by the
      cancel thread.
      
      scrub_setup_ctx() warns as tgtdev is NULL.
      
        struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
        {
        ...
      	  if (is_dev_replace) {
      		  WARN_ON(!fs_info->dev_replace.tgtdev);  <===
      		  sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
      		  sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
      		  sctx->flush_all_writes = false;
      	  }
      
        [ 6724.497655] BTRFS info (device sdb): dev_replace from /dev/sdb (devid 1) to /dev/sdc started
        [ 6753.945017] BTRFS info (device sdb): dev_replace from /dev/sdb (devid 1) to /dev/sdc canceled
        [ 6852.426700] WARNING: CPU: 0 PID: 4494 at fs/btrfs/scrub.c:622 scrub_setup_ctx.isra.19+0x220/0x230 [btrfs]
        ...
        [ 6852.428928] RIP: 0010:scrub_setup_ctx.isra.19+0x220/0x230 [btrfs]
        ...
        [ 6852.432970] Call Trace:
        [ 6852.433202]  btrfs_scrub_dev+0x19b/0x5c0 [btrfs]
        [ 6852.433471]  btrfs_dev_replace_start+0x48c/0x6a0 [btrfs]
        [ 6852.433800]  btrfs_dev_replace_by_ioctl+0x3a/0x60 [btrfs]
        [ 6852.434097]  btrfs_ioctl+0x2476/0x2d20 [btrfs]
        [ 6852.434365]  ? do_sigaction+0x7d/0x1e0
        [ 6852.434623]  do_vfs_ioctl+0xa9/0x6c0
        [ 6852.434865]  ? syscall_trace_enter+0x1c8/0x310
        [ 6852.435124]  ? syscall_trace_enter+0x1c8/0x310
        [ 6852.435387]  ksys_ioctl+0x60/0x90
        [ 6852.435663]  __x64_sys_ioctl+0x16/0x20
        [ 6852.435907]  do_syscall_64+0x50/0x180
        [ 6852.436150]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      Further, as the replace thread enters scrub_write_page_to_dev_replace()
      without the target device it panics:
      
        static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
      				      struct scrub_page *spage)
        {
        ...
      	bio_set_dev(bio, sbio->dev->bdev); <======
      
        [ 6929.715145] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
        ..
        [ 6929.717106] Workqueue: btrfs-scrub btrfs_scrub_helper [btrfs]
        [ 6929.717420] RIP: 0010:scrub_write_page_to_dev_replace+0xb4/0x260
        [btrfs]
        ..
        [ 6929.721430] Call Trace:
        [ 6929.721663]  scrub_write_block_to_dev_replace+0x3f/0x60 [btrfs]
        [ 6929.721975]  scrub_bio_end_io_worker+0x1af/0x490 [btrfs]
        [ 6929.722277]  normal_work_helper+0xf0/0x4c0 [btrfs]
        [ 6929.722552]  process_one_work+0x1f4/0x520
        [ 6929.722805]  ? process_one_work+0x16e/0x520
        [ 6929.723063]  worker_thread+0x46/0x3d0
        [ 6929.723313]  kthread+0xf8/0x130
        [ 6929.723544]  ? process_one_work+0x520/0x520
        [ 6929.723800]  ? kthread_delayed_work_timer_fn+0x80/0x80
        [ 6929.724081]  ret_from_fork+0x3a/0x50
      
      Fix this by letting the btrfs_dev_replace_finishing() to do the job of
      cleaning after the cancel, including freeing of the target device.
      btrfs_dev_replace_finishing() is called when btrfs_scub_dev() returns
      along with the scrub return status.
      Signed-off-by: NAnand Jain <anand.jain@oracle.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      38b17eee
    • H
      btrfs: alloc_chunk: fix more DUP stripe size handling · 720b86a5
      Hans van Kranenburg 提交于
      [ Upstream commit baf92114c7e6dd6124aa3d506e4bc4b694da3bc3 ]
      
      Commit 92e222df "btrfs: alloc_chunk: fix DUP stripe size handling"
      fixed calculating the stripe_size for a new DUP chunk.
      
      However, the same calculation reappears a bit later, and that one was
      not changed yet. The resulting bug that is exposed is that the newly
      allocated device extents ('stripes') can have a few MiB overlap with the
      next thing stored after them, which is another device extent or the end
      of the disk.
      
      The scenario in which this can happen is:
      * The block device for the filesystem is less than 10GiB in size.
      * The amount of contiguous free unallocated disk space chosen to use for
        chunk allocation is 20% of the total device size, or a few MiB more or
        less.
      
      An example:
      - The filesystem device is 7880MiB (max_chunk_size gets set to 788MiB)
      - There's 1578MiB unallocated raw disk space left in one contiguous
        piece.
      
      In this case stripe_size is first calculated as 789MiB, (half of
      1578MiB).
      
      Since 789MiB (stripe_size * data_stripes) > 788MiB (max_chunk_size), we
      enter the if block. Now stripe_size value is immediately overwritten
      while calculating an adjusted value based on max_chunk_size, which ends
      up as 788MiB.
      
      Next, the value is rounded up to a 16MiB boundary, 800MiB, which is
      actually more than the value we had before. However, the last comparison
      fails to detect this, because it's comparing the value with the total
      amount of free space, which is about twice the size of stripe_size.
      
      In the example above, this means that the resulting raw disk space being
      allocated is 1600MiB, while only a gap of 1578MiB has been found. The
      second device extent object for this DUP chunk will overlap for 22MiB
      with whatever comes next.
      
      The underlying problem here is that the stripe_size is reused all the
      time for different things. So, when entering the code in the if block,
      stripe_size is immediately overwritten with something else. If later we
      decide we want to have the previous value back, then the logic to
      compute it was copy pasted in again.
      
      With this change, the value in stripe_size is not unnecessarily
      destroyed, so the duplicated calculation is not needed any more.
      Signed-off-by: NHans van Kranenburg <hans.van.kranenburg@mendix.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      720b86a5
    • Q
      btrfs: volumes: Make sure there is no overlap of dev extents at mount time · bb5717a4
      Qu Wenruo 提交于
      [ Upstream commit 5eb193812a42dc49331f25137a38dfef9612d3e4 ]
      
      Enhance btrfs_verify_dev_extents() to remember previous checked dev
      extents, so it can verify no dev extents can overlap.
      
      Analysis from Hans:
      
      "Imagine allocating a DATA|DUP chunk.
      
       In the chunk allocator, we first set...
         max_stripe_size = SZ_1G;
         max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE
       ... which is 10GiB.
      
       Then...
         /* we don't want a chunk larger than 10% of writeable space */
         max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
             		 max_chunk_size);
      
       Imagine we only have one 7880MiB block device in this filesystem. Now
       max_chunk_size is down to 788MiB.
      
       The next step in the code is to search for max_stripe_size * dev_stripes
       amount of free space on the device, which is in our example 1GiB * 2 =
       2GiB. Imagine the device has exactly 1578MiB free in one contiguous
       piece. This amount of bytes will be put in devices_info[ndevs - 1].max_avail
      
       Next we recalculate the stripe_size (which is actually the device extent
       length), based on the actual maximum amount of available raw disk space:
         stripe_size = div_u64(devices_info[ndevs - 1].max_avail, dev_stripes);
      
       stripe_size is now 789MiB
      
       Next we do...
         data_stripes = num_stripes / ncopies
       ...where data_stripes ends up as 1, because num_stripes is 2 (the amount
       of device extents we're going to have), and DUP has ncopies 2.
      
       Next there's a check...
         if (stripe_size * data_stripes > max_chunk_size)
       ...which matches because 789MiB * 1 > 788MiB.
      
       We go into the if code, and next is...
         stripe_size = div_u64(max_chunk_size, data_stripes);
       ...which resets stripe_size to max_chunk_size: 788MiB
      
       Next is a fun one...
         /* bump the answer up to a 16MB boundary */
         stripe_size = round_up(stripe_size, SZ_16M);
       ...which changes stripe_size from 788MiB to 800MiB.
      
       We're not done changing stripe_size yet...
         /* But don't go higher than the limits we found while searching
          * for free extents
          */
         stripe_size = min(devices_info[ndevs - 1].max_avail,
             	      stripe_size);
      
       This is bad. max_avail is twice the stripe_size (we need to fit 2 device
       extents on the same device for DUP).
      
       The result here is that 800MiB < 1578MiB, so it's unchanged. However,
       the resulting DUP chunk will need 1600MiB disk space, which isn't there,
       and the second dev_extent might extend into the next thing (next
       dev_extent? end of device?) for 22MiB.
      
       The last shown line of code relies on a situation where there's twice
       the value of stripe_size present as value for the variable stripe_size
       when it's DUP. This was actually the case before commit 92e222df
       "btrfs: alloc_chunk: fix DUP stripe size handling", from which I quote:
         "[...] in the meantime there's a check to see if the stripe_size does
       not exceed max_chunk_size. Since during this check stripe_size is twice
       the amount as intended, the check will reduce the stripe_size to
       max_chunk_size if the actual correct to be used stripe_size is more than
       half the amount of max_chunk_size."
      
       In the previous version of the code, the 16MiB alignment (why is this
       done, by the way?) would result in a 50% chance that it would actually
       do an 8MiB alignment for the individual dev_extents, since it was
       operating on double the size. Does this matter?
      
       Does it matter that stripe_size can be set to anything which is not
       16MiB aligned because of the amount of remaining available disk space
       which is just taken?
      
       What is the main purpose of this round_up?
      
       The most straightforward thing to do seems something like...
         stripe_size = min(
             div_u64(devices_info[ndevs - 1].max_avail, dev_stripes),
             stripe_size
         )
       ..just putting half of the max_avail into stripe_size."
      
      Link: https://lore.kernel.org/linux-btrfs/b3461a38-e5f8-f41d-c67c-2efac8129054@mendix.com/Reported-by: NHans van Kranenburg <hans.van.kranenburg@mendix.com>
      Signed-off-by: NQu Wenruo <wqu@suse.com>
      [ add analysis from report ]
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      bb5717a4
  4. 23 1月, 2019 2 次提交
    • J
      btrfs: wait on ordered extents on abort cleanup · 01634ac5
      Josef Bacik 提交于
      commit 74d5d229b1bf60f93bff244b2dfc0eb21ec32a07 upstream.
      
      If we flip read-only before we initiate writeback on all dirty pages for
      ordered extents we've created then we'll have ordered extents left over
      on umount, which results in all sorts of bad things happening.  Fix this
      by making sure we wait on ordered extents if we have to do the aborted
      transaction cleanup stuff.
      
      generic/475 can produce this warning:
      
       [ 8531.177332] WARNING: CPU: 2 PID: 11997 at fs/btrfs/disk-io.c:3856 btrfs_free_fs_root+0x95/0xa0 [btrfs]
       [ 8531.183282] CPU: 2 PID: 11997 Comm: umount Tainted: G        W 5.0.0-rc1-default+ #394
       [ 8531.185164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
       [ 8531.187851] RIP: 0010:btrfs_free_fs_root+0x95/0xa0 [btrfs]
       [ 8531.193082] RSP: 0018:ffffb1ab86163d98 EFLAGS: 00010286
       [ 8531.194198] RAX: ffff9f3449494d18 RBX: ffff9f34a2695000 RCX:0000000000000000
       [ 8531.195629] RDX: 0000000000000002 RSI: 0000000000000001 RDI:0000000000000000
       [ 8531.197315] RBP: ffff9f344e930000 R08: 0000000000000001 R09:0000000000000000
       [ 8531.199095] R10: 0000000000000000 R11: ffff9f34494d4ff8 R12:ffffb1ab86163dc0
       [ 8531.200870] R13: ffff9f344e9300b0 R14: ffffb1ab86163db8 R15:0000000000000000
       [ 8531.202707] FS:  00007fc68e949fc0(0000) GS:ffff9f34bd800000(0000)knlGS:0000000000000000
       [ 8531.204851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       [ 8531.205942] CR2: 00007ffde8114dd8 CR3: 000000002dfbd000 CR4:00000000000006e0
       [ 8531.207516] Call Trace:
       [ 8531.208175]  btrfs_free_fs_roots+0xdb/0x170 [btrfs]
       [ 8531.210209]  ? wait_for_completion+0x5b/0x190
       [ 8531.211303]  close_ctree+0x157/0x350 [btrfs]
       [ 8531.212412]  generic_shutdown_super+0x64/0x100
       [ 8531.213485]  kill_anon_super+0x14/0x30
       [ 8531.214430]  btrfs_kill_super+0x12/0xa0 [btrfs]
       [ 8531.215539]  deactivate_locked_super+0x29/0x60
       [ 8531.216633]  cleanup_mnt+0x3b/0x70
       [ 8531.217497]  task_work_run+0x98/0xc0
       [ 8531.218397]  exit_to_usermode_loop+0x83/0x90
       [ 8531.219324]  do_syscall_64+0x15b/0x180
       [ 8531.220192]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
       [ 8531.221286] RIP: 0033:0x7fc68e5e4d07
       [ 8531.225621] RSP: 002b:00007ffde8116608 EFLAGS: 00000246 ORIG_RAX:00000000000000a6
       [ 8531.227512] RAX: 0000000000000000 RBX: 00005580c2175970 RCX:00007fc68e5e4d07
       [ 8531.229098] RDX: 0000000000000001 RSI: 0000000000000000 RDI:00005580c2175b80
       [ 8531.230730] RBP: 0000000000000000 R08: 00005580c2175ba0 R09:00007ffde8114e80
       [ 8531.232269] R10: 0000000000000000 R11: 0000000000000246 R12:00005580c2175b80
       [ 8531.233839] R13: 00007fc68eac61c4 R14: 00005580c2175a68 R15:0000000000000000
      
      Leaving a tree in the rb-tree:
      
      3853 void btrfs_free_fs_root(struct btrfs_root *root)
      3854 {
      3855         iput(root->ino_cache_inode);
      3856         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
      
      CC: stable@vger.kernel.org
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      [ add stacktrace ]
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      01634ac5
    • D
      Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io" · 4675f90e
      David Sterba 提交于
      commit 77b7aad195099e7c6da11e94b7fa6ef5e6fb0025 upstream.
      
      This reverts commit e73e81b6.
      
      This patch causes a few problems:
      
      - adds latency to btrfs_finish_ordered_io
      - as btrfs_finish_ordered_io is used for free space cache, generating
        more work from btrfs_btree_balance_dirty_nodelay could end up in the
        same workque, effectively deadlocking
      
      12260 kworker/u96:16+btrfs-freespace-write D
      [<0>] balance_dirty_pages+0x6e6/0x7ad
      [<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90
      [<0>] btrfs_finish_ordered_io+0x3da/0x770
      [<0>] normal_work_helper+0x1c5/0x5a0
      [<0>] process_one_work+0x1ee/0x5a0
      [<0>] worker_thread+0x46/0x3d0
      [<0>] kthread+0xf5/0x130
      [<0>] ret_from_fork+0x24/0x30
      [<0>] 0xffffffffffffffff
      
      Transaction commit will wait on the freespace cache:
      
      838 btrfs-transacti D
      [<0>] btrfs_start_ordered_extent+0x154/0x1e0
      [<0>] btrfs_wait_ordered_range+0xbd/0x110
      [<0>] __btrfs_wait_cache_io+0x49/0x1a0
      [<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0
      [<0>] commit_cowonly_roots+0x215/0x2b0
      [<0>] btrfs_commit_transaction+0x37e/0x910
      [<0>] transaction_kthread+0x14d/0x180
      [<0>] kthread+0xf5/0x130
      [<0>] ret_from_fork+0x24/0x30
      [<0>] 0xffffffffffffffff
      
      And then writepages ends up waiting on transaction commit:
      
      9520 kworker/u96:13+flush-btrfs-1 D
      [<0>] wait_current_trans+0xac/0xe0
      [<0>] start_transaction+0x21b/0x4b0
      [<0>] cow_file_range_inline+0x10b/0x6b0
      [<0>] cow_file_range.isra.69+0x329/0x4a0
      [<0>] run_delalloc_range+0x105/0x3c0
      [<0>] writepage_delalloc+0x119/0x180
      [<0>] __extent_writepage+0x10c/0x390
      [<0>] extent_write_cache_pages+0x26f/0x3d0
      [<0>] extent_writepages+0x4f/0x80
      [<0>] do_writepages+0x17/0x60
      [<0>] __writeback_single_inode+0x59/0x690
      [<0>] writeback_sb_inodes+0x291/0x4e0
      [<0>] __writeback_inodes_wb+0x87/0xb0
      [<0>] wb_writeback+0x3bb/0x500
      [<0>] wb_workfn+0x40d/0x610
      [<0>] process_one_work+0x1ee/0x5a0
      [<0>] worker_thread+0x1e0/0x3d0
      [<0>] kthread+0xf5/0x130
      [<0>] ret_from_fork+0x24/0x30
      [<0>] 0xffffffffffffffff
      
      Eventually, we have every process in the system waiting on
      balance_dirty_pages(), and nobody is able to make progress on page
      writeback.
      
      The original patch tried to fix an OOM condition, that happened on 4.4 but no
      success reproducing that on later kernels (4.19 and 4.20). This is more likely
      a problem in OOM itself.
      
      Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/Reported-by: NChris Mason <clm@fb.com>
      CC: stable@vger.kernel.org # 4.18+
      CC: ethanlien <ethanlien@synology.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4675f90e
  5. 17 1月, 2019 4 次提交
    • F
      Btrfs: use nofs context when initializing security xattrs to avoid deadlock · 7a1b9b76
      Filipe Manana 提交于
      commit 827aa18e7b903c5ff3b3cd8fec328a99b1dbd411 upstream.
      
      When initializing the security xattrs, we are holding a transaction handle
      therefore we need to use a GFP_NOFS context in order to avoid a deadlock
      with reclaim in case it's triggered.
      
      Fixes: 39a27ec1 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7a1b9b76
    • F
      Btrfs: fix deadlock when enabling quotas due to concurrent snapshot creation · 79aa5c0d
      Filipe Manana 提交于
      commit 9a6f209e36500efac51528132a3e3083586eda5f upstream.
      
      If the quota enable and snapshot creation ioctls are called concurrently
      we can get into a deadlock where the task enabling quotas will deadlock
      on the fs_info->qgroup_ioctl_lock mutex because it attempts to lock it
      twice, or the task creating a snapshot tries to commit the transaction
      while the task enabling quota waits for the former task to commit the
      transaction while holding the mutex. The following time diagrams show how
      both cases happen.
      
      First scenario:
      
                 CPU 0                                    CPU 1
      
       btrfs_ioctl()
        btrfs_ioctl_quota_ctl()
         btrfs_quota_enable()
          mutex_lock(fs_info->qgroup_ioctl_lock)
          btrfs_start_transaction()
      
                                                   btrfs_ioctl()
                                                    btrfs_ioctl_snap_create_v2
                                                     create_snapshot()
                                                      --> adds snapshot to the
                                                          list pending_snapshots
                                                          of the current
                                                          transaction
      
          btrfs_commit_transaction()
           create_pending_snapshots()
             create_pending_snapshot()
              qgroup_account_snapshot()
               btrfs_qgroup_inherit()
      	   mutex_lock(fs_info->qgroup_ioctl_lock)
      	    --> deadlock, mutex already locked
      	        by this task at
      		btrfs_quota_enable()
      
      Second scenario:
      
                 CPU 0                                    CPU 1
      
       btrfs_ioctl()
        btrfs_ioctl_quota_ctl()
         btrfs_quota_enable()
          mutex_lock(fs_info->qgroup_ioctl_lock)
          btrfs_start_transaction()
      
                                                   btrfs_ioctl()
                                                    btrfs_ioctl_snap_create_v2
                                                     create_snapshot()
                                                      --> adds snapshot to the
                                                          list pending_snapshots
                                                          of the current
                                                          transaction
      
                                                      btrfs_commit_transaction()
                                                       --> waits for task at
                                                           CPU 0 to release
                                                           its transaction
                                                           handle
      
          btrfs_commit_transaction()
           --> sees another task started
               the transaction commit first
           --> releases its transaction
               handle
           --> waits for the transaction
               commit to be completed by
               the task at CPU 1
      
                                                       create_pending_snapshot()
                                                        qgroup_account_snapshot()
                                                         btrfs_qgroup_inherit()
                                                          mutex_lock(fs_info->qgroup_ioctl_lock)
                                                           --> deadlock, task at CPU 0
                                                               has the mutex locked but
                                                               it is waiting for us to
                                                               finish the transaction
                                                               commit
      
      So fix this by setting the quota enabled flag in fs_info after committing
      the transaction at btrfs_quota_enable(). This ends up serializing quota
      enable and snapshot creation as if the snapshot creation happened just
      before the quota enable request. The quota rescan task, scheduled after
      committing the transaction in btrfs_quote_enable(), will do the accounting.
      
      Fixes: 6426c7ad ("btrfs: qgroup: Fix qgroup accounting when creating snapshot")
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      79aa5c0d
    • F
      Btrfs: fix access to available allocation bits when starting balance · 829431a2
      Filipe Manana 提交于
      commit 5a8067c0d17feb7579db0476191417b441a8996e upstream.
      
      The available allocation bits members from struct btrfs_fs_info are
      protected by a sequence lock, and when starting balance we access them
      incorrectly in two different ways:
      
      1) In the read sequence lock loop at btrfs_balance() we use the values we
         read from fs_info->avail_*_alloc_bits and we can immediately do actions
         that have side effects and can not be undone (printing a message and
         jumping to a label). This is wrong because a retry might be needed, so
         our actions must not have side effects and must be repeatable as long
         as read_seqretry() returns a non-zero value. In other words, we were
         essentially ignoring the sequence lock;
      
      2) Right below the read sequence lock loop, we were reading the values
         from avail_metadata_alloc_bits and avail_data_alloc_bits without any
         protection from concurrent writers, that is, reading them outside of
         the read sequence lock critical section.
      
      So fix this by making sure we only read the available allocation bits
      while in a read sequence lock critical section and that what we do in the
      critical section is repeatable (has nothing that can not be undone) so
      that any eventual retry that is needed is handled properly.
      
      Fixes: de98ced9 ("Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits")
      Fixes: 14506127 ("btrfs: fix a bogus warning when converting only data or metadata")
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      829431a2
    • F
      Btrfs: fix deadlock when using free space tree due to block group creation · d7068618
      Filipe Manana 提交于
      commit a6d8654d885d7d79a3fb82da64eaa489ca332a82 upstream.
      
      When modifying the free space tree we can end up COWing one of its extent
      buffers which in turn might result in allocating a new chunk, which in
      turn can result in flushing (finish creation) of pending block groups. If
      that happens we can deadlock because creating a pending block group needs
      to update the free space tree, and if any of the updates tries to modify
      the same extent buffer that we are COWing, we end up in a deadlock since
      we try to write lock twice the same extent buffer.
      
      So fix this by skipping pending block group creation if we are COWing an
      extent buffer from the free space tree. This is a case missed by commit
      5ce555578e091 ("Btrfs: fix deadlock when writing out free space caches").
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202173
      Fixes: 5ce555578e091 ("Btrfs: fix deadlock when writing out free space caches")
      CC: stable@vger.kernel.org # 4.18+
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d7068618
  6. 10 1月, 2019 6 次提交
    • F
      Btrfs: send, fix race with transaction commits that create snapshots · 9eec74b4
      Filipe Manana 提交于
      commit be6821f82c3cc36e026f5afd10249988852b35ea upstream.
      
      If we create a snapshot of a snapshot currently being used by a send
      operation, we can end up with send failing unexpectedly (returning
      -ENOENT error to user space for example). The following diagram shows
      how this happens.
      
                  CPU 1                                   CPU2                                CPU3
      
       btrfs_ioctl_send()
        (...)
                                           create_snapshot()
                                            -> creates snapshot of a
                                               root used by the send
                                               task
                                            btrfs_commit_transaction()
                                             create_pending_snapshot()
        __get_inode_info()
         btrfs_search_slot()
          btrfs_search_slot_get_root()
           down_read commit_root_sem
      
           get reference on eb of the
           commit root
            -> eb with bytenr == X
      
           up_read commit_root_sem
      
                                              btrfs_cow_block(root node)
                                               btrfs_free_tree_block()
                                                -> creates delayed ref to
                                                   free the extent
      
                                             btrfs_run_delayed_refs()
                                              -> runs the delayed ref,
                                                 adds extent to
                                                 fs_info->pinned_extents
      
                                             btrfs_finish_extent_commit()
                                              unpin_extent_range()
                                               -> marks extent as free
                                                  in the free space cache
      
                                            transaction commit finishes
      
                                                                             btrfs_start_transaction()
                                                                              (...)
                                                                              btrfs_cow_block()
                                                                               btrfs_alloc_tree_block()
                                                                                btrfs_reserve_extent()
                                                                                 -> allocates extent at
                                                                                    bytenr == X
                                                                                btrfs_init_new_buffer(bytenr X)
                                                                                 btrfs_find_create_tree_block()
                                                                                  alloc_extent_buffer(bytenr X)
                                                                                   find_extent_buffer(bytenr X)
                                                                                    -> returns existing eb,
                                                                                       which the send task got
      
                                                                              (...)
                                                                               -> modifies content of the
                                                                                  eb with bytenr == X
      
          -> uses an eb that now
             belongs to some other
             tree and no more matches
             the commit root of the
             snapshot, resuts will be
             unpredictable
      
      The consequences of this race can be various, and can lead to searches in
      the commit root performed by the send task failing unexpectedly (unable to
      find inode items, returning -ENOENT to user space, for example) or not
      failing because an inode item with the same number was added to the tree
      that reused the metadata extent, in which case send can behave incorrectly
      in the worst case or just fail later for some reason.
      
      Fix this by performing a copy of the commit root's extent buffer when doing
      a search in the context of a send operation.
      
      CC: stable@vger.kernel.org # 4.4.x: 1fc28d8e: Btrfs: move get root out of btrfs_search_slot to a helper
      CC: stable@vger.kernel.org # 4.4.x: f9ddfd05: Btrfs: remove unused check of skip_locking
      CC: stable@vger.kernel.org # 4.4.x
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9eec74b4
    • J
      btrfs: run delayed items before dropping the snapshot · 6911b074
      Josef Bacik 提交于
      commit 0568e82dbe2510fc1fa664f58e5c997d3f1e649e upstream.
      
      With my delayed refs patches in place we started seeing a large amount
      of aborts in __btrfs_free_extent:
      
       BTRFS error (device sdb1): unable to find ref byte nr 91947008 parent 0 root 35964  owner 1 offset 0
       Call Trace:
        ? btrfs_merge_delayed_refs+0xaf/0x340
        __btrfs_run_delayed_refs+0x6ea/0xfc0
        ? btrfs_set_path_blocking+0x31/0x60
        btrfs_run_delayed_refs+0xeb/0x180
        btrfs_commit_transaction+0x179/0x7f0
        ? btrfs_check_space_for_delayed_refs+0x30/0x50
        ? should_end_transaction.isra.19+0xe/0x40
        btrfs_drop_snapshot+0x41c/0x7c0
        btrfs_clean_one_deleted_snapshot+0xb5/0xd0
        cleaner_kthread+0xf6/0x120
        kthread+0xf8/0x130
        ? btree_invalidatepage+0x90/0x90
        ? kthread_bind+0x10/0x10
        ret_from_fork+0x35/0x40
      
      This was because btrfs_drop_snapshot depends on the root not being
      modified while it's dropping the snapshot.  It will unlock the root node
      (and really every node) as it walks down the tree, only to re-lock it
      when it needs to do something.  This is a problem because if we modify
      the tree we could cow a block in our path, which frees our reference to
      that block.  Then once we get back to that shared block we'll free our
      reference to it again, and get ENOENT when trying to lookup our extent
      reference to that block in __btrfs_free_extent.
      
      This is ultimately happening because we have delayed items left to be
      processed for our deleted snapshot _after_ all of the inodes are closed
      for the snapshot.  We only run the delayed inode item if we're deleting
      the inode, and even then we do not run the delayed insertions or delayed
      removals.  These can be run at any point after our final inode does its
      last iput, which is what triggers the snapshot deletion.  We can end up
      with the snapshot deletion happening and then have the delayed items run
      on that file system, resulting in the above problem.
      
      This problem has existed forever, however my patches made it much easier
      to hit as I wake up the cleaner much more often to deal with delayed
      iputs, which made us more likely to start the snapshot dropping work
      before the transaction commits, which is when the delayed items would
      generally be run.  Before, generally speaking, we would run the delayed
      items, commit the transaction, and wakeup the cleaner thread to start
      deleting snapshots, which means we were less likely to hit this problem.
      You could still hit it if you had multiple snapshots to be deleted and
      ended up with lots of delayed items, but it was definitely harder.
      
      Fix for now by simply running all the delayed items before starting to
      drop the snapshot.  We could make this smarter in the future by making
      the delayed items per-root, and then simply drop any delayed items for
      roots that we are going to delete.  But for now just a quick and easy
      solution is the safest.
      
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6911b074
    • F
      Btrfs: fix fsync of files with multiple hard links in new directories · 10b04210
      Filipe Manana 提交于
      commit 41bd60676923822de1df2c50b3f9a10171f4338a upstream.
      
      The log tree has a long standing problem that when a file is fsync'ed we
      only check for new ancestors, created in the current transaction, by
      following only the hard link for which the fsync was issued. We follow the
      ancestors using the VFS' dget_parent() API. This means that if we create a
      new link for a file in a directory that is new (or in an any other new
      ancestor directory) and then fsync the file using an old hard link, we end
      up not logging the new ancestor, and on log replay that new hard link and
      ancestor do not exist. In some cases, involving renames, the file will not
      exist at all.
      
      Example:
      
        mkfs.btrfs -f /dev/sdb
        mount /dev/sdb /mnt
      
        mkdir /mnt/A
        touch /mnt/foo
        ln /mnt/foo /mnt/A/bar
        xfs_io -c fsync /mnt/foo
      
        <power failure>
      
      In this example after log replay only the hard link named 'foo' exists
      and directory A does not exist, which is unexpected. In other major linux
      filesystems, such as ext4, xfs and f2fs for example, both hard links exist
      and so does directory A after mounting again the filesystem.
      
      Checking if any new ancestors are new and need to be logged was added in
      2009 by commit 12fcfd22 ("Btrfs: tree logging unlink/rename fixes"),
      however only for the ancestors of the hard link (dentry) for which the
      fsync was issued, instead of checking for all ancestors for all of the
      inode's hard links.
      
      So fix this by tracking the id of the last transaction where a hard link
      was created for an inode and then on fsync fallback to a full transaction
      commit when an inode has more than one hard link and at least one new hard
      link was created in the current transaction. This is the simplest solution
      since this is not a common use case (adding frequently hard links for
      which there's an ancestor created in the current transaction and then
      fsync the file). In case it ever becomes a common use case, a solution
      that consists of iterating the fs/subvol btree for each hard link and
      check if any ancestor is new, could be implemented.
      
      This solves many unexpected scenarios reported by Jayashree Mohan and
      Vijay Chidambaram, and for which there is a new test case for fstests
      under review.
      
      Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes")
      CC: stable@vger.kernel.org # 4.4+
      Reported-by: NVijay Chidambaram <vvijay03@gmail.com>
      Reported-by: NJayashree Mohan <jayashree2912@gmail.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      10b04210
    • L
      btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow · 7708a830
      Lu Fengqi 提交于
      commit 27a7ff554e8d349627a90bda275c527b7348adae upstream.
      
      The test case btrfs/001 with inode_cache mount option will encounter the
      following warning:
      
        WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs]
        CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G        W  O      4.20.0-rc4-custom+ #30
        Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
        RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs]
        Call Trace:
         ? free_extent_buffer+0x46/0x90 [btrfs]
         run_delalloc_nocow+0x455/0x900 [btrfs]
         btrfs_run_delalloc_range+0x1a7/0x360 [btrfs]
         writepage_delalloc+0xf9/0x150 [btrfs]
         __extent_writepage+0x125/0x3e0 [btrfs]
         extent_write_cache_pages+0x1b6/0x3e0 [btrfs]
         ? __wake_up_common_lock+0x63/0xc0
         extent_writepages+0x50/0x80 [btrfs]
         do_writepages+0x41/0xd0
         ? __filemap_fdatawrite_range+0x9e/0xf0
         __filemap_fdatawrite_range+0xbe/0xf0
         btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
         __btrfs_write_out_cache+0x42c/0x480 [btrfs]
         btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
         btrfs_save_ino_cache+0x551/0x660 [btrfs]
         commit_fs_roots+0xc5/0x190 [btrfs]
         btrfs_commit_transaction+0x2bf/0x8d0 [btrfs]
         btrfs_mksubvol+0x48d/0x4d0 [btrfs]
         btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs]
         btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs]
         btrfs_ioctl+0x123f/0x3030 [btrfs]
      
      The file extent generation of the free space inode is equal to the last
      snapshot of the file root, so the inode will be passed to cow_file_rage.
      But the inode was created and its extents were preallocated in
      btrfs_save_ino_cache, there are no cow copies on disk.
      
      The preallocated extent is not yet in the extent tree, and
      btrfs_cross_ref_exist will ignore the -ENOENT returned by
      check_committed_ref, so we can directly write the inode to the disk.
      
      Fixes: 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path")
      CC: stable@vger.kernel.org # 4.18+
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7708a830
    • A
      btrfs: dev-replace: go back to suspend state if another EXCL_OP is running · c1f90eb0
      Anand Jain 提交于
      commit 05c49e6bc1e8866ecfd674ebeeb58cdbff9145c2 upstream.
      
      In a secnario where balance and replace co-exists as below,
      
        - start balance
        - pause balance
        - start replace
        - reboot
      
      and when system restarts, balance resumes first. Then the replace is
      attempted to restart but will fail as the EXCL_OP lock is already held
      by the balance. If so place the replace state back to
      BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state.
      
      Fixes: 010a47bd ("btrfs: add proper safety check before resuming dev-replace")
      CC: stable@vger.kernel.org # 4.18+
      Signed-off-by: NAnand Jain <anand.jain@oracle.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c1f90eb0
    • A
      btrfs: dev-replace: go back to suspended state if target device is missing · 28867a52
      Anand Jain 提交于
      commit 0d228ece59a35a9b9e8ff0d40653234a6d90f61e upstream.
      
      At the time of forced unmount we place the running replace to
      BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state, so when the system comes
      back and expect the target device is missing.
      
      Then let the replace state continue to be in
      BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state instead of
      BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED as there isn't any matching scrub
      running as part of replace.
      
      Fixes: e93c89c1 ("Btrfs: add new sources for device replace code")
      CC: stable@vger.kernel.org # 4.4+
      Signed-off-by: NAnand Jain <anand.jain@oracle.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      28867a52
  7. 21 12月, 2018 1 次提交
    • O
      Btrfs: fix missing delayed iputs on unmount · b4c7c826
      Omar Sandoval 提交于
      [ Upstream commit d6fd0ae25c6495674dc5a41a8d16bc8e0073276d ]
      
      There's a race between close_ctree() and cleaner_kthread().
      close_ctree() sets btrfs_fs_closing(), and the cleaner stops when it
      sees it set, but this is racy; the cleaner might have already checked
      the bit and could be cleaning stuff. In particular, if it deletes unused
      block groups, it will create delayed iputs for the free space cache
      inodes. As of "btrfs: don't run delayed_iputs in commit", we're no
      longer running delayed iputs after a commit. Therefore, if the cleaner
      creates more delayed iputs after delayed iputs are run in
      btrfs_commit_super(), we will leak inodes on unmount and get a busy
      inode crash from the VFS.
      
      Fix it by parking the cleaner before we actually close anything. Then,
      any remaining delayed iputs will always be handled in
      btrfs_commit_super(). This also ensures that the commit in close_ctree()
      is really the last commit, so we can get rid of the commit in
      cleaner_kthread().
      
      The fstest/generic/475 followed by 476 can trigger a crash that
      manifests as a slab corruption caused by accessing the freed kthread
      structure by a wake up function. Sample trace:
      
      [ 5657.077612] BUG: unable to handle kernel NULL pointer dereference at 00000000000000cc
      [ 5657.079432] PGD 1c57a067 P4D 1c57a067 PUD da10067 PMD 0
      [ 5657.080661] Oops: 0000 [#1] PREEMPT SMP
      [ 5657.081592] CPU: 1 PID: 5157 Comm: fsstress Tainted: G        W         4.19.0-rc8-default+ #323
      [ 5657.083703] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
      [ 5657.086577] RIP: 0010:shrink_page_list+0x2f9/0xe90
      [ 5657.091937] RSP: 0018:ffffb5c745c8f728 EFLAGS: 00010287
      [ 5657.092953] RAX: 0000000000000074 RBX: ffffb5c745c8f830 RCX: 0000000000000000
      [ 5657.094590] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a8747fdf3d0
      [ 5657.095987] RBP: ffffb5c745c8f9e0 R08: 0000000000000000 R09: 0000000000000000
      [ 5657.097159] R10: ffff9a8747fdf5e8 R11: 0000000000000000 R12: ffffb5c745c8f788
      [ 5657.098513] R13: ffff9a877f6ff2c0 R14: ffff9a877f6ff2c8 R15: dead000000000200
      [ 5657.099689] FS:  00007f948d853b80(0000) GS:ffff9a877d600000(0000) knlGS:0000000000000000
      [ 5657.101032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 5657.101953] CR2: 00000000000000cc CR3: 00000000684bd000 CR4: 00000000000006e0
      [ 5657.103159] Call Trace:
      [ 5657.103776]  shrink_inactive_list+0x194/0x410
      [ 5657.104671]  shrink_node_memcg.constprop.84+0x39a/0x6a0
      [ 5657.105750]  shrink_node+0x62/0x1c0
      [ 5657.106529]  try_to_free_pages+0x1a4/0x500
      [ 5657.107408]  __alloc_pages_slowpath+0x2c9/0xb20
      [ 5657.108418]  __alloc_pages_nodemask+0x268/0x2b0
      [ 5657.109348]  kmalloc_large_node+0x37/0x90
      [ 5657.110205]  __kmalloc_node+0x236/0x310
      [ 5657.111014]  kvmalloc_node+0x3e/0x70
      
      Fixes: 30928e9baac2 ("btrfs: don't run delayed_iputs in commit")
      Signed-off-by: NOmar Sandoval <osandov@fb.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      [ add trace ]
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      b4c7c826
  8. 17 12月, 2018 1 次提交
    • R
      Btrfs: send, fix infinite loop due to directory rename dependencies · 91f6a9aa
      Robbie Ko 提交于
      [ Upstream commit a4390aee72713d9e73f1132bcdeb17d72fbbf974 ]
      
      When doing an incremental send, due to the need of delaying directory move
      (rename) operations we can end up in infinite loop at
      apply_children_dir_moves().
      
      An example scenario that triggers this problem is described below, where
      directory names correspond to the numbers of their respective inodes.
      
      Parent snapshot:
      
       .
       |--- 261/
             |--- 271/
                   |--- 266/
                         |--- 259/
                         |--- 260/
                         |     |--- 267
                         |
                         |--- 264/
                         |     |--- 258/
                         |           |--- 257/
                         |
                         |--- 265/
                         |--- 268/
                         |--- 269/
                         |     |--- 262/
                         |
                         |--- 270/
                         |--- 272/
                         |     |--- 263/
                         |     |--- 275/
                         |
                         |--- 274/
                               |--- 273/
      
      Send snapshot:
      
       .
       |-- 275/
            |-- 274/
                 |-- 273/
                      |-- 262/
                           |-- 269/
                                |-- 258/
                                     |-- 271/
                                          |-- 268/
                                               |-- 267/
                                                    |-- 270/
                                                         |-- 259/
                                                         |    |-- 265/
                                                         |
                                                         |-- 272/
                                                              |-- 257/
                                                                   |-- 260/
                                                                   |-- 264/
                                                                        |-- 263/
                                                                             |-- 261/
                                                                                  |-- 266/
      
      When processing inode 257 we delay its move (rename) operation because its
      new parent in the send snapshot, inode 272, was not yet processed. Then
      when processing inode 272, we delay the move operation for that inode
      because inode 274 is its ancestor in the send snapshot. Finally we delay
      the move operation for inode 274 when processing it because inode 275 is
      its new parent in the send snapshot and was not yet moved.
      
      When finishing processing inode 275, we start to do the move operations
      that were previously delayed (at apply_children_dir_moves()), resulting in
      the following iterations:
      
      1) We issue the move operation for inode 274;
      
      2) Because inode 262 depended on the move operation of inode 274 (it was
         delayed because 274 is its ancestor in the send snapshot), we issue the
         move operation for inode 262;
      
      3) We issue the move operation for inode 272, because it was delayed by
         inode 274 too (ancestor of 272 in the send snapshot);
      
      4) We issue the move operation for inode 269 (it was delayed by 262);
      
      5) We issue the move operation for inode 257 (it was delayed by 272);
      
      6) We issue the move operation for inode 260 (it was delayed by 272);
      
      7) We issue the move operation for inode 258 (it was delayed by 269);
      
      8) We issue the move operation for inode 264 (it was delayed by 257);
      
      9) We issue the move operation for inode 271 (it was delayed by 258);
      
      10) We issue the move operation for inode 263 (it was delayed by 264);
      
      11) We issue the move operation for inode 268 (it was delayed by 271);
      
      12) We verify if we can issue the move operation for inode 270 (it was
          delayed by 271). We detect a path loop in the current state, because
          inode 267 needs to be moved first before we can issue the move
          operation for inode 270. So we delay again the move operation for
          inode 270, this time we will attempt to do it after inode 267 is
          moved;
      
      13) We issue the move operation for inode 261 (it was delayed by 263);
      
      14) We verify if we can issue the move operation for inode 266 (it was
          delayed by 263). We detect a path loop in the current state, because
          inode 270 needs to be moved first before we can issue the move
          operation for inode 266. So we delay again the move operation for
          inode 266, this time we will attempt to do it after inode 270 is
          moved (its move operation was delayed in step 12);
      
      15) We issue the move operation for inode 267 (it was delayed by 268);
      
      16) We verify if we can issue the move operation for inode 266 (it was
          delayed by 270). We detect a path loop in the current state, because
          inode 270 needs to be moved first before we can issue the move
          operation for inode 266. So we delay again the move operation for
          inode 266, this time we will attempt to do it after inode 270 is
          moved (its move operation was delayed in step 12). So here we added
          again the same delayed move operation that we added in step 14;
      
      17) We attempt again to see if we can issue the move operation for inode
          266, and as in step 16, we realize we can not due to a path loop in
          the current state due to a dependency on inode 270. Again we delay
          inode's 266 rename to happen after inode's 270 move operation, adding
          the same dependency to the empty stack that we did in steps 14 and 16.
          The next iteration will pick the same move dependency on the stack
          (the only entry) and realize again there is still a path loop and then
          again the same dependency to the stack, over and over, resulting in
          an infinite loop.
      
      So fix this by preventing adding the same move dependency entries to the
      stack by removing each pending move record from the red black tree of
      pending moves. This way the next call to get_pending_dir_moves() will
      not return anything for the current parent inode.
      
      A test case for fstests, with this reproducer, follows soon.
      Signed-off-by: NRobbie Ko <robbieko@synology.com>
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      [Wrote changelog with example and more clear explanation]
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      91f6a9aa
  9. 08 12月, 2018 1 次提交
    • Q
      btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable · b0234f15
      Qu Wenruo 提交于
      commit 10950929e994c5ecee149ff0873388d3c98f12b5 upstream.
      
      [BUG]
      A completely valid btrfs will refuse to mount, with error message like:
        BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \
          bg_start=12018974720 bg_len=10888413184, invalid block group size, \
          have 10888413184 expect (0, 10737418240]
      
      This has been reported several times as the 4.19 kernel is now being
      used. The filesystem refuses to mount, but is otherwise ok and booting
      4.18 is a workaround.
      
      Btrfs check returns no error, and all kernels used on this fs is later
      than 2011, which should all have the 10G size limit commit.
      
      [CAUSE]
      For a 12 devices btrfs, we could allocate a chunk larger than 10G due to
      stripe stripe bump up.
      
      __btrfs_alloc_chunk()
      |- max_stripe_size = 1G
      |- max_chunk_size = 10G
      |- data_stripe = 11
      |- if (1G * 11 > 10G) {
             stripe_size = 976128930;
             stripe_size = round_up(976128930, SZ_16M) = 989855744
      
      However the final stripe_size (989855744) * 11 = 10888413184, which is
      still larger than 10G.
      
      [FIX]
      For the comprehensive check, we need to do the full check at chunk read
      time, and rely on bg <-> chunk mapping to do the check.
      
      We could just skip the length check for now.
      
      Fixes: fce466ea ("btrfs: tree-checker: Verify block_group_item")
      Cc: stable@vger.kernel.org # v4.19+
      Reported-by: NWang Yugui <wangyugui@e16-tech.com>
      Signed-off-by: NQu Wenruo <wqu@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b0234f15
  10. 06 12月, 2018 5 次提交
    • P
      btrfs: relocation: set trans to be NULL after ending transaction · 59065765
      Pan Bian 提交于
      commit 42a657f57628402c73237547f0134e083e2f6764 upstream.
      
      The function relocate_block_group calls btrfs_end_transaction to release
      trans when update_backref_cache returns 1, and then continues the loop
      body. If btrfs_block_rsv_refill fails this time, it will jump out the
      loop and the freed trans will be accessed. This may result in a
      use-after-free bug. The patch assigns NULL to trans after trans is
      released so that it will not be accessed.
      
      Fixes: 0647bf56 ("Btrfs: improve forever loop when doing balance relocation")
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NQu Wenruo <wqu@suse.com>
      Signed-off-by: NPan Bian <bianpan2016@163.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      59065765
    • F
      Btrfs: fix race between enabling quotas and subvolume creation · 172a94eb
      Filipe Manana 提交于
      commit 552f0329c75b3e1d7f9bb8c9e421d37403f192cd upstream.
      
      We have a race between enabling quotas end subvolume creation that cause
      subvolume creation to fail with -EINVAL, and the following diagram shows
      how it happens:
      
                    CPU 0                                          CPU 1
      
       btrfs_ioctl()
        btrfs_ioctl_quota_ctl()
         btrfs_quota_enable()
          mutex_lock(fs_info->qgroup_ioctl_lock)
      
                                                        btrfs_ioctl()
                                                         create_subvol()
                                                          btrfs_qgroup_inherit()
                                                           -> save fs_info->quota_root
                                                              into quota_root
                                                           -> stores a NULL value
                                                           -> tries to lock the mutex
                                                              qgroup_ioctl_lock
                                                              -> blocks waiting for
                                                                 the task at CPU0
      
         -> sets BTRFS_FS_QUOTA_ENABLED in fs_info
         -> sets quota_root in fs_info->quota_root
            (non-NULL value)
      
         mutex_unlock(fs_info->qgroup_ioctl_lock)
      
                                                           -> checks quota enabled
                                                              flag is set
                                                           -> returns -EINVAL because
                                                              fs_info->quota_root was
                                                              NULL before it acquired
                                                              the mutex
                                                              qgroup_ioctl_lock
                                                         -> ioctl returns -EINVAL
      
      Returning -EINVAL to user space will be confusing if all the arguments
      passed to the subvolume creation ioctl were valid.
      
      Fix it by grabbing the value from fs_info->quota_root after acquiring
      the mutex.
      
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NQu Wenruo <wqu@suse.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      172a94eb
    • F
      Btrfs: fix rare chances for data loss when doing a fast fsync · 715608db
      Filipe Manana 提交于
      commit aab15e8ec25765cf7968c72cbec7583acf99d8a4 upstream.
      
      After the simplification of the fast fsync patch done recently by commit
      b5e6c3e1 ("btrfs: always wait on ordered extents at fsync time") and
      commit e7175a69 ("btrfs: remove the wait ordered logic in the
      log_one_extent path"), we got a very short time window where we can get
      extents logged without writeback completing first or extents logged
      without logging the respective data checksums. Both issues can only happen
      when doing a non-full (fast) fsync.
      
      As soon as we enter btrfs_sync_file() we trigger writeback, then lock the
      inode and then wait for the writeback to complete before starting to log
      the inode. However before we acquire the inode's lock and after we started
      writeback, it's possible that more writes happened and dirtied more pages.
      If that happened and those pages get writeback triggered while we are
      logging the inode (for example, the VM subsystem triggering it due to
      memory pressure, or another concurrent fsync), we end up seeing the
      respective extent maps in the inode's list of modified extents and will
      log matching file extent items without waiting for the respective
      ordered extents to complete, meaning that either of the following will
      happen:
      
      1) We log an extent after its writeback finishes but before its checksums
         are added to the csum tree, leading to -EIO errors when attempting to
         read the extent after a log replay.
      
      2) We log an extent before its writeback finishes.
         Therefore after the log replay we will have a file extent item pointing
         to an unwritten extent (and without the respective data checksums as
         well).
      
      This could not happen before the fast fsync patch simplification, because
      for any extent we found in the list of modified extents, we would wait for
      its respective ordered extent to finish writeback or collect its checksums
      for logging if it did not complete yet.
      
      Fix this by triggering writeback again after acquiring the inode's lock
      and before waiting for ordered extents to complete.
      
      Fixes: e7175a69 ("btrfs: remove the wait ordered logic in the log_one_extent path")
      Fixes: b5e6c3e1 ("btrfs: always wait on ordered extents at fsync time")
      CC: stable@vger.kernel.org # 4.19+
      Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      715608db
    • F
      Btrfs: ensure path name is null terminated at btrfs_control_ioctl · 78a2890f
      Filipe Manana 提交于
      commit f505754fd6599230371cb01b9332754ddc104be1 upstream.
      
      We were using the path name received from user space without checking that
      it is null terminated. While btrfs-progs is well behaved and does proper
      validation and null termination, someone could call the ioctl and pass
      a non-null terminated patch, leading to buffer overrun problems in the
      kernel.  The ioctl is protected by CAP_SYS_ADMIN.
      
      So just set the last byte of the path to a null character, similar to what
      we do in other ioctls (add/remove/resize device, snapshot creation, etc).
      
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NAnand Jain <anand.jain@oracle.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      78a2890f
    • N
      btrfs: Always try all copies when reading extent buffers · aaf249e3
      Nikolay Borisov 提交于
      commit f8397d69daef06d358430d3054662fb597e37c00 upstream.
      
      When a metadata read is served the endio routine btree_readpage_end_io_hook
      is called which eventually runs the tree-checker. If tree-checker fails
      to validate the read eb then it sets EXTENT_BUFFER_CORRUPT flag. This
      leads to btree_read_extent_buffer_pages wrongly assuming that all
      available copies of this extent buffer are wrong and failing prematurely.
      Fix this modify btree_read_extent_buffer_pages to read all copies of
      the data.
      
      This failure was exhibitted in xfstests btrfs/124 which would
      spuriously fail its balance operations. The reason was that when balance
      was run following re-introduction of the missing raid1 disk
      __btrfs_map_block would map the read request to stripe 0, which
      corresponded to devid 2 (the disk which is being removed in the test):
      
          item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 3553624064) itemoff 15975 itemsize 112
      	length 1073741824 owner 2 stripe_len 65536 type DATA|RAID1
      	io_align 65536 io_width 65536 sector_size 4096
      	num_stripes 2 sub_stripes 1
      		stripe 0 devid 2 offset 2156920832
      		dev_uuid 8466c350-ed0c-4c3b-b17d-6379b445d5c8
      		stripe 1 devid 1 offset 3553624064
      		dev_uuid 1265d8db-5596-477e-af03-df08eb38d2ca
      
      This caused read requests for a checksum item that to be routed to the
      stale disk which triggered the aforementioned logic involving
      EXTENT_BUFFER_CORRUPT flag. This then triggered cascading failures of
      the balance operation.
      
      Fixes: a826d6dc ("Btrfs: check items for correctness as we search")
      CC: stable@vger.kernel.org # 4.4+
      Suggested-by: NQu Wenruo <wqu@suse.com>
      Reviewed-by: NQu Wenruo <wqu@suse.com>
      Signed-off-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      aaf249e3
  11. 21 11月, 2018 6 次提交
    • S
      btrfs: tree-checker: Fix misleading group system information · f2589f9a
      Shaokun Zhang 提交于
      commit 761333f2f50ccc887aa9957ae829300262c0d15b upstream.
      
      block_group_err shows the group system as a decimal value with a '0x'
      prefix, which is somewhat misleading.
      
      Fix it to print hexadecimal, as was intended.
      
      Fixes: fce466ea ("btrfs: tree-checker: Verify block_group_item")
      CC: stable@vger.kernel.org # 4.19+
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Reviewed-by: NQu Wenruo <wqu@suse.com>
      Signed-off-by: NShaokun Zhang <zhangshaokun@hisilicon.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f2589f9a
    • F
      Btrfs: fix data corruption due to cloning of eof block · ec6d90a4
      Filipe Manana 提交于
      commit ac765f83f1397646c11092a032d4f62c3d478b81 upstream.
      
      We currently allow cloning a range from a file which includes the last
      block of the file even if the file's size is not aligned to the block
      size. This is fine and useful when the destination file has the same size,
      but when it does not and the range ends somewhere in the middle of the
      destination file, it leads to corruption because the bytes between the EOF
      and the end of the block have undefined data (when there is support for
      discard/trimming they have a value of 0x00).
      
      Example:
      
       $ mkfs.btrfs -f /dev/sdb
       $ mount /dev/sdb /mnt
      
       $ export foo_size=$((256 * 1024 + 100))
       $ xfs_io -f -c "pwrite -S 0x3c 0 $foo_size" /mnt/foo
       $ xfs_io -f -c "pwrite -S 0xb5 0 1M" /mnt/bar
      
       $ xfs_io -c "reflink /mnt/foo 0 512K $foo_size" /mnt/bar
      
       $ od -A d -t x1 /mnt/bar
       0000000 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
       *
       0524288 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c
       *
       0786528 3c 3c 3c 3c 00 00 00 00 00 00 00 00 00 00 00 00
       0786544 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
       *
       0790528 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
       *
       1048576
      
      The bytes in the range from 786532 (512Kb + 256Kb + 100 bytes) to 790527
      (512Kb + 256Kb + 4Kb - 1) got corrupted, having now a value of 0x00 instead
      of 0xb5.
      
      This is similar to the problem we had for deduplication that got recently
      fixed by commit de02b9f6 ("Btrfs: fix data corruption when
      deduplicating between different files").
      
      Fix this by not allowing such operations to be performed and return the
      errno -EINVAL to user space. This is what XFS is doing as well at the VFS
      level. This change however now makes us return -EINVAL instead of
      -EOPNOTSUPP for cases where the source range maps to an inline extent and
      the destination range's end is smaller then the destination file's size,
      since the detection of inline extents is done during the actual process of
      dropping file extent items (at __btrfs_drop_extents()). Returning the
      -EINVAL error is done early on and solely based on the input parameters
      (offsets and length) and destination file's size. This makes us consistent
      with XFS and anyone else supporting cloning since this case is now checked
      at a higher level in the VFS and is where the -EINVAL will be returned
      from starting with kernel 4.20 (the VFS changed was introduced in 4.20-rc1
      by commit 07d19dc9fbe9 ("vfs: avoid problematic remapping requests into
      partial EOF block"). So this change is more geared towards stable kernels,
      as it's unlikely the new VFS checks get removed intentionally.
      
      A test case for fstests follows soon, as well as an update to filter
      existing tests that expect -EOPNOTSUPP to accept -EINVAL as well.
      
      CC: <stable@vger.kernel.org> # 4.4+
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ec6d90a4
    • F
      Btrfs: fix infinite loop on inode eviction after deduplication of eof block · bafd5b78
      Filipe Manana 提交于
      commit 11023d3f5fdf89bba5e1142127701ca6e6014587 upstream.
      
      If we attempt to deduplicate the last block of a file A into the middle of
      a file B, and file A's size is not a multiple of the block size, we end
      rounding the deduplication length to 0 bytes, to avoid the data corruption
      issue fixed by commit de02b9f6 ("Btrfs: fix data corruption when
      deduplicating between different files"). However a length of zero will
      cause the insertion of an extent state with a start value greater (by 1)
      then the end value, leading to a corrupt extent state that will trigger a
      warning and cause chaos such as an infinite loop during inode eviction.
      Example trace:
      
       [96049.833585] ------------[ cut here ]------------
       [96049.833714] WARNING: CPU: 0 PID: 24448 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
       [96049.833767] CPU: 0 PID: 24448 Comm: xfs_io Not tainted 4.19.0-rc7-btrfs-next-39 #1
       [96049.833768] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
       [96049.833780] RIP: 0010:insert_state+0x101/0x120 [btrfs]
       [96049.833783] RSP: 0018:ffffafd2c3707af0 EFLAGS: 00010282
       [96049.833785] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
       [96049.833786] RDX: 0000000000000007 RSI: ffff99045c143230 RDI: ffff99047b2168a0
       [96049.833787] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
       [96049.833787] R10: ffffafd2c3707ab8 R11: 0000000000000000 R12: ffff9903b93b12c8
       [96049.833788] R13: 000000000004e000 R14: ffffafd2c3707b80 R15: ffffafd2c3707b78
       [96049.833790] FS:  00007f5c14e7d700(0000) GS:ffff99047b200000(0000) knlGS:0000000000000000
       [96049.833791] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       [96049.833792] CR2: 00007f5c146abff8 CR3: 0000000115f4c004 CR4: 00000000003606f0
       [96049.833795] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       [96049.833796] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
       [96049.833796] Call Trace:
       [96049.833809]  __set_extent_bit+0x46c/0x6a0 [btrfs]
       [96049.833823]  lock_extent_bits+0x6b/0x210 [btrfs]
       [96049.833831]  ? _raw_spin_unlock+0x24/0x30
       [96049.833841]  ? test_range_bit+0xdf/0x130 [btrfs]
       [96049.833853]  lock_extent_range+0x8e/0x150 [btrfs]
       [96049.833864]  btrfs_double_extent_lock+0x78/0xb0 [btrfs]
       [96049.833875]  btrfs_extent_same_range+0x14e/0x550 [btrfs]
       [96049.833885]  ? rcu_read_lock_sched_held+0x3f/0x70
       [96049.833890]  ? __kmalloc_node+0x2b0/0x2f0
       [96049.833899]  ? btrfs_dedupe_file_range+0x19a/0x280 [btrfs]
       [96049.833909]  btrfs_dedupe_file_range+0x270/0x280 [btrfs]
       [96049.833916]  vfs_dedupe_file_range_one+0xd9/0xe0
       [96049.833919]  vfs_dedupe_file_range+0x131/0x1b0
       [96049.833924]  do_vfs_ioctl+0x272/0x6e0
       [96049.833927]  ? __fget+0x113/0x200
       [96049.833931]  ksys_ioctl+0x70/0x80
       [96049.833933]  __x64_sys_ioctl+0x16/0x20
       [96049.833937]  do_syscall_64+0x60/0x1b0
       [96049.833939]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
       [96049.833941] RIP: 0033:0x7f5c1478ddd7
       [96049.833943] RSP: 002b:00007ffe15b196a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
       [96049.833945] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1478ddd7
       [96049.833946] RDX: 00005625ece322d0 RSI: 00000000c0189436 RDI: 0000000000000004
       [96049.833947] RBP: 0000000000000000 R08: 00007f5c14a46f48 R09: 0000000000000040
       [96049.833948] R10: 0000000000000541 R11: 0000000000000202 R12: 0000000000000000
       [96049.833949] R13: 0000000000000000 R14: 0000000000000004 R15: 00005625ece322d0
       [96049.833954] irq event stamp: 6196
       [96049.833956] hardirqs last  enabled at (6195): [<ffffffff91b00663>] console_unlock+0x503/0x640
       [96049.833958] hardirqs last disabled at (6196): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
       [96049.833959] softirqs last  enabled at (6114): [<ffffffff92600370>] __do_softirq+0x370/0x421
       [96049.833964] softirqs last disabled at (6095): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
       [96049.833965] ---[ end trace db7b05f01b7fa10c ]---
       [96049.935816] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
       [96049.935822] irq event stamp: 6584
       [96049.935823] hardirqs last  enabled at (6583): [<ffffffff91b00663>] console_unlock+0x503/0x640
       [96049.935825] hardirqs last disabled at (6584): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
       [96049.935827] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
       [96049.935828] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
       [96049.935829] ---[ end trace db7b05f01b7fa123 ]---
       [96049.935840] ------------[ cut here ]------------
       [96049.936065] WARNING: CPU: 1 PID: 24463 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
       [96049.936107] CPU: 1 PID: 24463 Comm: umount Tainted: G        W         4.19.0-rc7-btrfs-next-39 #1
       [96049.936108] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
       [96049.936117] RIP: 0010:insert_state+0x101/0x120 [btrfs]
       [96049.936119] RSP: 0018:ffffafd2c3637bc0 EFLAGS: 00010282
       [96049.936120] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
       [96049.936121] RDX: 0000000000000007 RSI: ffff990445cf88e0 RDI: ffff99047b2968a0
       [96049.936122] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
       [96049.936123] R10: ffffafd2c3637b88 R11: 0000000000000000 R12: ffff9904574301e8
       [96049.936124] R13: 000000000004e000 R14: ffffafd2c3637c50 R15: ffffafd2c3637c48
       [96049.936125] FS:  00007fe4b87e72c0(0000) GS:ffff99047b280000(0000) knlGS:0000000000000000
       [96049.936126] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       [96049.936128] CR2: 00005562e52618d8 CR3: 00000001151c8005 CR4: 00000000003606e0
       [96049.936129] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       [96049.936131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
       [96049.936131] Call Trace:
       [96049.936141]  __set_extent_bit+0x46c/0x6a0 [btrfs]
       [96049.936154]  lock_extent_bits+0x6b/0x210 [btrfs]
       [96049.936167]  btrfs_evict_inode+0x1e1/0x5a0 [btrfs]
       [96049.936172]  evict+0xbf/0x1c0
       [96049.936174]  dispose_list+0x51/0x80
       [96049.936176]  evict_inodes+0x193/0x1c0
       [96049.936180]  generic_shutdown_super+0x3f/0x110
       [96049.936182]  kill_anon_super+0xe/0x30
       [96049.936189]  btrfs_kill_super+0x13/0x100 [btrfs]
       [96049.936191]  deactivate_locked_super+0x3a/0x70
       [96049.936193]  cleanup_mnt+0x3b/0x80
       [96049.936195]  task_work_run+0x93/0xc0
       [96049.936198]  exit_to_usermode_loop+0xfa/0x100
       [96049.936201]  do_syscall_64+0x17f/0x1b0
       [96049.936202]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
       [96049.936204] RIP: 0033:0x7fe4b80cfb37
       [96049.936206] RSP: 002b:00007ffff092b688 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
       [96049.936207] RAX: 0000000000000000 RBX: 00005562e5259060 RCX: 00007fe4b80cfb37
       [96049.936208] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00005562e525faa0
       [96049.936209] RBP: 00005562e525faa0 R08: 00005562e525f770 R09: 0000000000000015
       [96049.936210] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fe4b85d1e64
       [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
       [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
       [96049.936216] irq event stamp: 6616
       [96049.936219] hardirqs last  enabled at (6615): [<ffffffff91b00663>] console_unlock+0x503/0x640
       [96049.936219] hardirqs last disabled at (6616): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
       [96049.936222] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
       [96049.936222] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
       [96049.936223] ---[ end trace db7b05f01b7fa124 ]---
      
      The second stack trace, from inode eviction, is repeated forever due to
      the infinite loop during eviction.
      
      This is the same type of problem fixed way back in 2015 by commit
      113e8283 ("Btrfs: fix inode eviction infinite loop after extent_same
      ioctl") and commit ccccf3d6 ("Btrfs: fix inode eviction infinite loop
      after cloning into it").
      
      So fix this by returning immediately if the deduplication range length
      gets rounded down to 0 bytes, as there is nothing that needs to be done in
      such case.
      
      Example reproducer:
      
       $ mkfs.btrfs -f /dev/sdb
       $ mount /dev/sdb /mnt
      
       $ xfs_io -f -c "pwrite -S 0xe6 0 100" /mnt/foo
       $ xfs_io -f -c "pwrite -S 0xe6 0 1M" /mnt/bar
      
       # Unmount the filesystem and mount it again so that we start without any
       # extent state records when we ask for the deduplication.
       $ umount /mnt
       $ mount /dev/sdb /mnt
      
       $ xfs_io -c "dedupe /mnt/foo 0 500K 100" /mnt/bar
      
       # This unmount triggers the infinite loop.
       $ umount /mnt
      
      A test case for fstests will follow soon.
      
      Fixes: de02b9f6 ("Btrfs: fix data corruption when deduplicating between different files")
      CC: <stable@vger.kernel.org> # 4.19+
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bafd5b78
    • R
      Btrfs: fix cur_offset in the error case for nocow · db39065c
      Robbie Ko 提交于
      commit 506481b20e818db40b6198815904ecd2d6daee64 upstream.
      
      When the cow_file_range fails, the related resources are unlocked
      according to the range [start..end), so the unlock cannot be repeated in
      run_delalloc_nocow.
      
      In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is
      not updated correctly, so move the cur_offset update before
      cow_file_range.
      
        kernel BUG at mm/page-writeback.c:2663!
        Internal error: Oops - BUG: 0 [#1] SMP
        CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O
        Hardware name: Realtek_RTD1296 (DT)
        Workqueue: writeback wb_workfn (flush-btrfs-1)
        task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000
        PC is at clear_page_dirty_for_io+0x1bc/0x1e8
        LR is at clear_page_dirty_for_io+0x14/0x1e8
        pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145
        sp : ffffffc02e9af4f0
        Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020)
        Call trace:
        [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8
        [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs]
        [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs]
        [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs]
        [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs]
        [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs]
        [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs]
        [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs]
        [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs]
        [<ffffffc00033d758>] do_writepages+0x30/0x88
        [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198
        [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0
        [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0
        [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0
        [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250
        [<ffffffc0002b0014>] process_one_work+0x1dc/0x388
        [<ffffffc0002b02f0>] worker_thread+0x130/0x500
        [<ffffffc0002b6344>] kthread+0x10c/0x110
        [<ffffffc000284590>] ret_from_fork+0x10/0x40
        Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000)
      
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NRobbie Ko <robbieko@synology.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      db39065c
    • F
      Btrfs: fix missing data checksums after a ranged fsync (msync) · fa625a48
      Filipe Manana 提交于
      commit 008c6753f7e070c77c70d708a6bf0255b4381763 upstream.
      
      Recently we got a massive simplification for fsync, where for the fast
      path we no longer log new extents while their respective ordered extents
      are still running.
      
      However that simplification introduced a subtle regression for the case
      where we use a ranged fsync (msync). Consider the following example:
      
                     CPU 0                                    CPU 1
      
                                                  mmap write to range [2Mb, 4Mb[
        mmap write to range [512Kb, 1Mb[
        msync range [512K, 1Mb[
          --> triggers fast fsync
              (BTRFS_INODE_NEEDS_FULL_SYNC
               not set)
          --> creates extent map A for this
              range and adds it to list of
              modified extents
          --> starts ordered extent A for
              this range
          --> waits for it to complete
      
                                                  writeback triggered for range
                                                  [2Mb, 4Mb[
                                                    --> create extent map B and
                                                        adds it to the list of
                                                        modified extents
                                                    --> creates ordered extent B
      
          --> start looking for and logging
              modified extents
          --> logs extent maps A and B
          --> finds checksums for extent A
              in the csum tree, but not for
              extent B
        fsync (msync) finishes
      
                                                    --> ordered extent B
                                                        finishes and its
                                                        checksums are added
                                                        to the csum tree
      
                                      <power cut>
      
      After replaying the log, we have the extent covering the range [2Mb, 4Mb[
      but do not have the data checksum items covering that file range.
      
      This happens because at the very beginning of an fsync (btrfs_sync_file())
      we start and wait for IO in the given range [512Kb, 1Mb[ and therefore
      wait for any ordered extents in that range to complete before we start
      logging the extents. However if right before we start logging the extent
      in our range [512Kb, 1Mb[, writeback is started for any other dirty range,
      such as the range [2Mb, 4Mb[ due to memory pressure or a concurrent fsync
      or msync (btrfs_sync_file() starts writeback before acquiring the inode's
      lock), an ordered extent is created for that other range and a new extent
      map is created to represent that range and added to the inode's list of
      modified extents.
      
      That means that we will see that other extent in that list when collecting
      extents for logging (done at btrfs_log_changed_extents()) and log the
      extent before the respective ordered extent finishes - namely before the
      checksum items are added to the checksums tree, which is where
      log_extent_csums() looks for the checksums, therefore making us log an
      extent without logging its checksums. Before that massive simplification
      of fsync, this wasn't a problem because besides looking for checkums in
      the checksums tree, we also looked for them in any ordered extent still
      running.
      
      The consequence of data checksums missing for a file range is that users
      attempting to read the affected file range will get -EIO errors and dmesg
      reports the following:
      
       [10188.358136] BTRFS info (device sdc): no csum found for inode 297 start 57344
       [10188.359278] BTRFS warning (device sdc): csum failed root 5 ino 297 off 57344 csum 0x98f94189 expected csum 0x00000000 mirror 1
      
      So fix this by skipping extents outside of our logging range at
      btrfs_log_changed_extents() and leaving them on the list of modified
      extents so that any subsequent ranged fsync may collect them if needed.
      Also, if we find a hole extent outside of the range still log it, just
      to prevent having gaps between extent items after replaying the log,
      otherwise fsck will complain when we are not using the NO_HOLES feature
      (fstest btrfs/056 triggers such case).
      
      Fixes: e7175a69 ("btrfs: remove the wait ordered logic in the log_one_extent path")
      CC: stable@vger.kernel.org # 4.19+
      Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fa625a48
    • L
      btrfs: fix pinned underflow after transaction aborted · ec26ad25
      Lu Fengqi 提交于
      commit fcd5e74288f7d36991b1f0fb96b8c57079645e38 upstream.
      
      When running generic/475, we may get the following warning in dmesg:
      
      [ 6902.102154] WARNING: CPU: 3 PID: 18013 at fs/btrfs/extent-tree.c:9776 btrfs_free_block_groups+0x2af/0x3b0 [btrfs]
      [ 6902.109160] CPU: 3 PID: 18013 Comm: umount Tainted: G        W  O      4.19.0-rc8+ #8
      [ 6902.110971] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
      [ 6902.112857] RIP: 0010:btrfs_free_block_groups+0x2af/0x3b0 [btrfs]
      [ 6902.118921] RSP: 0018:ffffc9000459bdb0 EFLAGS: 00010286
      [ 6902.120315] RAX: ffff880175050bb0 RBX: ffff8801124a8000 RCX: 0000000000170007
      [ 6902.121969] RDX: 0000000000000002 RSI: 0000000000170007 RDI: ffffffff8125fb74
      [ 6902.123716] RBP: ffff880175055d10 R08: 0000000000000000 R09: 0000000000000000
      [ 6902.125417] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880175055d88
      [ 6902.127129] R13: ffff880175050bb0 R14: 0000000000000000 R15: dead000000000100
      [ 6902.129060] FS:  00007f4507223780(0000) GS:ffff88017ba00000(0000) knlGS:0000000000000000
      [ 6902.130996] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 6902.132558] CR2: 00005623599cac78 CR3: 000000014b700001 CR4: 00000000003606e0
      [ 6902.134270] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      [ 6902.135981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      [ 6902.137836] Call Trace:
      [ 6902.138939]  close_ctree+0x171/0x330 [btrfs]
      [ 6902.140181]  ? kthread_stop+0x146/0x1f0
      [ 6902.141277]  generic_shutdown_super+0x6c/0x100
      [ 6902.142517]  kill_anon_super+0x14/0x30
      [ 6902.143554]  btrfs_kill_super+0x13/0x100 [btrfs]
      [ 6902.144790]  deactivate_locked_super+0x2f/0x70
      [ 6902.146014]  cleanup_mnt+0x3b/0x70
      [ 6902.147020]  task_work_run+0x9e/0xd0
      [ 6902.148036]  do_syscall_64+0x470/0x600
      [ 6902.149142]  ? trace_hardirqs_off_thunk+0x1a/0x1c
      [ 6902.150375]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
      [ 6902.151640] RIP: 0033:0x7f45077a6a7b
      [ 6902.157324] RSP: 002b:00007ffd589f3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
      [ 6902.159187] RAX: 0000000000000000 RBX: 000055e8eec732b0 RCX: 00007f45077a6a7b
      [ 6902.160834] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055e8eec73490
      [ 6902.162526] RBP: 0000000000000000 R08: 000055e8eec734b0 R09: 00007ffd589f26c0
      [ 6902.164141] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e8eec73490
      [ 6902.165815] R13: 00007f4507ac61a4 R14: 0000000000000000 R15: 00007ffd589f40d8
      [ 6902.167553] irq event stamp: 0
      [ 6902.168998] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
      [ 6902.170731] hardirqs last disabled at (0): [<ffffffff810cd810>] copy_process.part.55+0x3b0/0x1f00
      [ 6902.172773] softirqs last  enabled at (0): [<ffffffff810cd810>] copy_process.part.55+0x3b0/0x1f00
      [ 6902.174671] softirqs last disabled at (0): [<0000000000000000>]           (null)
      [ 6902.176407] ---[ end trace 463138c2986b275c ]---
      [ 6902.177636] BTRFS info (device dm-3): space_info 4 has 273465344 free, is not full
      [ 6902.179453] BTRFS info (device dm-3): space_info total=276824064, used=4685824, pinned=18446744073708158976, reserved=0, may_use=0, readonly=65536
      
      In the above line there's "pinned=18446744073708158976" which is an
      unsigned u64 value of -1392640, an obvious underflow.
      
      When transaction_kthread is running cleanup_transaction(), another
      fsstress is running btrfs_commit_transaction(). The
      btrfs_finish_extent_commit() may get the same range as
      btrfs_destroy_pinned_extent() got, which causes the pinned underflow.
      
      Fixes: d4b450cd ("Btrfs: fix race between transaction commit and empty block group removal")
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ec26ad25
  12. 14 11月, 2018 6 次提交
    • F
      Btrfs: fix use-after-free when dumping free space · 0c286e9d
      Filipe Manana 提交于
      commit 9084cb6a24bf5838a665af92ded1af8363f9e563 upstream.
      
      We were iterating a block group's free space cache rbtree without locking
      first the lock that protects it (the free_space_ctl->free_space_offset
      rbtree is protected by the free_space_ctl->tree_lock spinlock).
      
      KASAN reported an use-after-free problem when iterating such a rbtree due
      to a concurrent rbtree delete:
      
      [ 9520.359168] ==================================================================
      [ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
      [ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
      [ 9520.360357]
      [ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor #555
      [ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
      [ 9520.362682] Call Trace:
      [ 9520.362887]  dump_stack+0xa4/0xf5
      [ 9520.363146]  print_address_description+0x78/0x280
      [ 9520.363412]  kasan_report+0x263/0x390
      [ 9520.363650]  ? rb_next+0x13/0x90
      [ 9520.363873]  __asan_load8+0x54/0x90
      [ 9520.364102]  rb_next+0x13/0x90
      [ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
      [ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
      [ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
      [ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
      [ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
      [ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
      [ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
      [ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
      [ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
      [ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
      [ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
      [ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
      [ 9520.368104]  ? kasan_check_read+0x11/0x20
      [ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
      [ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
      [ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
      [ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
      [ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
      [ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
      [ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
      [ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
      [ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
      [ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
      [ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
      [ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
      [ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
      [ 9520.372537]  kthread+0x1d2/0x1f0
      [ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
      [ 9520.373090]  ? kthread_park+0xb0/0xb0
      [ 9520.373329]  ret_from_fork+0x3a/0x50
      [ 9520.373567]
      [ 9520.373738] Allocated by task 1804:
      [ 9520.373974]  kasan_kmalloc+0xff/0x180
      [ 9520.374208]  kasan_slab_alloc+0x11/0x20
      [ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
      [ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
      [ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
      [ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
      [ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
      [ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
      [ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
      [ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
      [ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
      [ 9520.377284]  generic_file_direct_write+0x11e/0x220
      [ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
      [ 9520.377875]  aio_write+0x25c/0x360
      [ 9520.378106]  io_submit_one+0xaa0/0xdc0
      [ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
      [ 9520.378589]  __x64_sys_io_submit+0x43/0x50
      [ 9520.378840]  do_syscall_64+0x7d/0x240
      [ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
      [ 9520.379387]
      [ 9520.379557] Freed by task 1802:
      [ 9520.379782]  __kasan_slab_free+0x173/0x260
      [ 9520.380028]  kasan_slab_free+0xe/0x10
      [ 9520.380262]  kmem_cache_free+0xc1/0x2c0
      [ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
      [ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
      [ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
      [ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
      [ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
      [ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
      [ 9520.382321]  generic_file_direct_write+0x11e/0x220
      [ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
      [ 9520.382904]  aio_write+0x25c/0x360
      [ 9520.383172]  io_submit_one+0xaa0/0xdc0
      [ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
      [ 9520.383678]  __x64_sys_io_submit+0x43/0x50
      [ 9520.383927]  do_syscall_64+0x7d/0x240
      [ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
      [ 9520.384439]
      [ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                      which belongs to the cache btrfs_free_space of size 72
      [ 9520.385175] The buggy address is located 0 bytes inside of
                      72-byte region [ffff8800b7ada500, ffff8800b7ada548)
      [ 9520.385691] The buggy address belongs to the page:
      [ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
      [ 9520.388030] flags: 0x8100(slab|head)
      [ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
      [ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
      [ 9520.389169] page dumped because: kasan: bad access detected
      [ 9520.389473]
      [ 9520.389658] Memory state around the buggy address:
      [ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      [ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      [ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
      [ 9520.391223]                    ^
      [ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      [ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      [ 9520.392313] ==================================================================
      [ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
      [ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
      [ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
      [ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
      [ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor #555
      [ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
      [ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
      [ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
      [ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
      [ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
      [ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
      [ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
      [ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
      [ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
      [ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
      [ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      [ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      [ 9520.400400] Call Trace:
      [ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
      [ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
      [ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
      [ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
      [ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
      [ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
      [ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
      [ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
      [ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
      [ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
      [ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
      [ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
      [ 9520.404481]  ? kasan_check_read+0x11/0x20
      [ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
      [ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
      [ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
      [ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
      [ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
      [ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
      [ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
      [ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
      [ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
      [ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
      [ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
      [ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
      [ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
      [ 9520.408870]  kthread+0x1d2/0x1f0
      [ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
      [ 9520.409440]  ? kthread_park+0xb0/0xb0
      [ 9520.409682]  ret_from_fork+0x3a/0x50
      [ 9520.410508] Dumping ftrace buffer:
      [ 9520.410764]    (ftrace buffer empty)
      [ 9520.411007] CR2: 0000000000000011
      [ 9520.411297] ---[ end trace 01a0863445cf360a ]---
      [ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
      [ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
      [ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
      [ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
      [ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
      [ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
      [ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
      [ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
      [ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
      [ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      [ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      [ 9520.419204] Kernel panic - not syncing: Fatal exception
      [ 9520.419666] Dumping ftrace buffer:
      [ 9520.419930]    (ftrace buffer empty)
      [ 9520.420168] Kernel Offset: disabled
      [ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---
      
      Fix this by acquiring the respective lock before iterating the rbtree.
      Reported-by: NNikolay Borisov <nborisov@suse.com>
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0c286e9d
    • F
      Btrfs: fix use-after-free during inode eviction · 5b7a4630
      Filipe Manana 提交于
      commit 421f0922a2cfb0c75acd9746454aaa576c711a65 upstream.
      
      At inode.c:evict_inode_truncate_pages(), when we iterate over the
      inode's extent states, we access an extent state record's "state" field
      after we unlocked the inode's io tree lock. This can lead to a
      use-after-free issue because after we unlock the io tree that extent
      state record might have been freed due to being merged into another
      adjacent extent state record (a previous inflight bio for a read
      operation finished in the meanwhile which unlocked a range in the io
      tree and cause a merge of extent state records, as explained in the
      comment before the while loop added in commit 6ca07097 ("Btrfs: fix
      hang during inode eviction due to concurrent readahead")).
      
      Fix this by keeping a copy of the extent state's flags in a local
      variable and using it after unlocking the io tree.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201189
      Fixes: b9d0b389 ("btrfs: Add handler for invalidate page")
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NQu Wenruo <wqu@suse.com>
      Signed-off-by: NFilipe Manana <fdmanana@suse.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5b7a4630
    • J
      btrfs: move the dio_sem higher up the callchain · 51c62a33
      Josef Bacik 提交于
      commit c495144bc6962186feae31d687596d2472000e45 upstream.
      
      We're getting a lockdep splat because we take the dio_sem under the
      log_mutex.  What we really need is to protect fsync() from logging an
      extent map for an extent we never waited on higher up, so just guard the
      whole thing with dio_sem.
      
      ======================================================
      WARNING: possible circular locking dependency detected
      4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Not tainted
      ------------------------------------------------------
      aio-dio-invalid/30928 is trying to acquire lock:
      0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0
      
      but task is already holding lock:
      00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #5 (&ei->dio_sem){++++}:
             lock_acquire+0xbd/0x220
             down_write+0x51/0xb0
             btrfs_log_changed_extents+0x80/0xa40
             btrfs_log_inode+0xbaf/0x1000
             btrfs_log_inode_parent+0x26f/0xa80
             btrfs_log_dentry_safe+0x50/0x70
             btrfs_sync_file+0x357/0x540
             do_fsync+0x38/0x60
             __ia32_sys_fdatasync+0x12/0x20
             do_fast_syscall_32+0x9a/0x2f0
             entry_SYSENTER_compat+0x84/0x96
      
      -> #4 (&ei->log_mutex){+.+.}:
             lock_acquire+0xbd/0x220
             __mutex_lock+0x86/0xa10
             btrfs_record_unlink_dir+0x2a/0xa0
             btrfs_unlink+0x5a/0xc0
             vfs_unlink+0xb1/0x1a0
             do_unlinkat+0x264/0x2b0
             do_fast_syscall_32+0x9a/0x2f0
             entry_SYSENTER_compat+0x84/0x96
      
      -> #3 (sb_internal#2){.+.+}:
             lock_acquire+0xbd/0x220
             __sb_start_write+0x14d/0x230
             start_transaction+0x3e6/0x590
             btrfs_evict_inode+0x475/0x640
             evict+0xbf/0x1b0
             btrfs_run_delayed_iputs+0x6c/0x90
             cleaner_kthread+0x124/0x1a0
             kthread+0x106/0x140
             ret_from_fork+0x3a/0x50
      
      -> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}:
             lock_acquire+0xbd/0x220
             __mutex_lock+0x86/0xa10
             btrfs_alloc_data_chunk_ondemand+0x197/0x530
             btrfs_check_data_free_space+0x4c/0x90
             btrfs_delalloc_reserve_space+0x20/0x60
             btrfs_page_mkwrite+0x87/0x520
             do_page_mkwrite+0x31/0xa0
             __handle_mm_fault+0x799/0xb00
             handle_mm_fault+0x7c/0xe0
             __do_page_fault+0x1d3/0x4a0
             async_page_fault+0x1e/0x30
      
      -> #1 (sb_pagefaults){.+.+}:
             lock_acquire+0xbd/0x220
             __sb_start_write+0x14d/0x230
             btrfs_page_mkwrite+0x6a/0x520
             do_page_mkwrite+0x31/0xa0
             __handle_mm_fault+0x799/0xb00
             handle_mm_fault+0x7c/0xe0
             __do_page_fault+0x1d3/0x4a0
             async_page_fault+0x1e/0x30
      
      -> #0 (&mm->mmap_sem){++++}:
             __lock_acquire+0x42e/0x7a0
             lock_acquire+0xbd/0x220
             down_read+0x48/0xb0
             get_user_pages_unlocked+0x5a/0x1e0
             get_user_pages_fast+0xa4/0x150
             iov_iter_get_pages+0xc3/0x340
             do_direct_IO+0xf93/0x1d70
             __blockdev_direct_IO+0x32d/0x1c20
             btrfs_direct_IO+0x227/0x400
             generic_file_direct_write+0xcf/0x180
             btrfs_file_write_iter+0x308/0x58c
             aio_write+0xf8/0x1d0
             io_submit_one+0x3a9/0x620
             __ia32_compat_sys_io_submit+0xb2/0x270
             do_int80_syscall_32+0x5b/0x1a0
             entry_INT80_compat+0x88/0xa0
      
      other info that might help us debug this:
      
      Chain exists of:
        &mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem
      
       Possible unsafe locking scenario:
      
             CPU0                    CPU1
             ----                    ----
        lock(&ei->dio_sem);
                                     lock(&ei->log_mutex);
                                     lock(&ei->dio_sem);
        lock(&mm->mmap_sem);
      
       *** DEADLOCK ***
      
      1 lock held by aio-dio-invalid/30928:
       #0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400
      
      stack backtrace:
      CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
      Call Trace:
       dump_stack+0x7c/0xbb
       print_circular_bug.isra.37+0x297/0x2a4
       check_prev_add.constprop.45+0x781/0x7a0
       ? __lock_acquire+0x42e/0x7a0
       validate_chain.isra.41+0x7f0/0xb00
       __lock_acquire+0x42e/0x7a0
       lock_acquire+0xbd/0x220
       ? get_user_pages_unlocked+0x5a/0x1e0
       down_read+0x48/0xb0
       ? get_user_pages_unlocked+0x5a/0x1e0
       get_user_pages_unlocked+0x5a/0x1e0
       get_user_pages_fast+0xa4/0x150
       iov_iter_get_pages+0xc3/0x340
       do_direct_IO+0xf93/0x1d70
       ? __alloc_workqueue_key+0x358/0x490
       ? __blockdev_direct_IO+0x14b/0x1c20
       __blockdev_direct_IO+0x32d/0x1c20
       ? btrfs_run_delalloc_work+0x40/0x40
       ? can_nocow_extent+0x490/0x490
       ? kvm_clock_read+0x1f/0x30
       ? can_nocow_extent+0x490/0x490
       ? btrfs_run_delalloc_work+0x40/0x40
       btrfs_direct_IO+0x227/0x400
       ? btrfs_run_delalloc_work+0x40/0x40
       generic_file_direct_write+0xcf/0x180
       btrfs_file_write_iter+0x308/0x58c
       aio_write+0xf8/0x1d0
       ? kvm_clock_read+0x1f/0x30
       ? __might_fault+0x3e/0x90
       io_submit_one+0x3a9/0x620
       ? io_submit_one+0xe5/0x620
       __ia32_compat_sys_io_submit+0xb2/0x270
       do_int80_syscall_32+0x5b/0x1a0
       entry_INT80_compat+0x88/0xa0
      
      CC: stable@vger.kernel.org # 4.14+
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      51c62a33
    • J
      btrfs: don't run delayed_iputs in commit · dd472956
      Josef Bacik 提交于
      commit 30928e9baac238a7330085a1c5747f0b5df444b4 upstream.
      
      This could result in a really bad case where we do something like
      
      evict
        evict_refill_and_join
          btrfs_commit_transaction
            btrfs_run_delayed_iputs
              evict
                evict_refill_and_join
                  btrfs_commit_transaction
      ... forever
      
      We have plenty of other places where we run delayed iputs that are much
      safer, let those do the work.
      
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dd472956
    • J
      btrfs: fix insert_reserved error handling · 186b5248
      Josef Bacik 提交于
      commit 80ee54bfe8a3850015585ebc84e8d207fcae6831 upstream.
      
      We were not handling the reserved byte accounting properly for data
      references.  Metadata was fine, if it errored out the error paths would
      free the bytes_reserved count and pin the extent, but it even missed one
      of the error cases.  So instead move this handling up into
      run_one_delayed_ref so we are sure that both cases are properly cleaned
      up in case of a transaction abort.
      
      CC: stable@vger.kernel.org # 4.18+
      Reviewed-by: NNikolay Borisov <nborisov@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      Reviewed-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      186b5248
    • J
      btrfs: only free reserved extent if we didn't insert it · 5a1e9bf4
      Josef Bacik 提交于
      commit 49940bdd57779c78462da7aa5a8650b2fea8c2ff upstream.
      
      When we insert the file extent once the ordered extent completes we free
      the reserved extent reservation as it'll have been migrated to the
      bytes_used counter.  However if we error out after this step we'll still
      clear the reserved extent reservation, resulting in a negative
      accounting of the reserved bytes for the block group and space info.
      Fix this by only doing the free if we didn't successfully insert a file
      extent for this extent.
      
      CC: stable@vger.kernel.org # 4.14+
      Reviewed-by: NOmar Sandoval <osandov@fb.com>
      Reviewed-by: NFilipe Manana <fdmanana@suse.com>
      Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: NDavid Sterba <dsterba@suse.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5a1e9bf4