1. 30 Nov, 2011 9 commits
    • Alexandre Oliva's avatar
      Btrfs: skip block groups without enough space for a cluster · 425d8315
      Alexandre Oliva authored
      We test whether a block group has enough free space to hold the
      requested block, but when we're doing clustered allocation, we can
      save some cycles by testing whether it has enough room for the cluster
      upfront, otherwise we end up attempting to set up a cluster and
      failing.  Only in the NO_EMPTY_SIZE loop do we attempt an unclustered
      allocation, and by then we'll have zeroed the cluster size, so this
      patch won't stop us from using the block group as a last resort.
      Signed-off-by: default avatarAlexandre Oliva <oliva@lsd.ic.unicamp.br>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      425d8315
    • Alexandre Oliva's avatar
      Btrfs: start search for new cluster at the beginning · 1b22bad7
      Alexandre Oliva authored
      Instead of starting at zero (offset is always zero), request a cluster
      starting at search_start, that denotes the beginning of the current
      block group.
      Signed-off-by: default avatarAlexandre Oliva <oliva@lsd.ic.unicamp.br>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      1b22bad7
    • Alexandre Oliva's avatar
      Btrfs: reset cluster's max_size when creating bitmap · b78d09bc
      Alexandre Oliva authored
      The field that indicates the size of the largest contiguous chunk of
      free space in the cluster is not initialized when setting up bitmaps,
      it's only increased when we find a larger contiguous chunk.  We end up
      retaining a larger value than appropriate for highly-fragmented
      clusters, which may cause pointless searches for large contiguous
      groups, and even cause clusters that do not meet the density
      requirements to be set up.
      Signed-off-by: default avatarAlexandre Oliva <oliva@lsd.ic.unicamp.br>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      b78d09bc
    • Alexandre Oliva's avatar
      Btrfs: initialize new bitmaps' list · f2d0f676
      Alexandre Oliva authored
      We're failing to create clusters with bitmaps because
      setup_cluster_no_bitmap checks that the list is empty before inserting
      the bitmap entry in the list for setup_cluster_bitmap, but the list
      field is only initialized when it is restored from the on-disk free
      space cache, or when it is written out to disk.
      
      Besides a potential race condition due to the multiple use of the list
      field, filesystem performance severely degrades over time: as we use
      up all non-bitmap free extents, the try-to-set-up-cluster dance is
      done at every metadata block allocation.  For every block group, we
      fail to set up a cluster, and after failing on them all up to twice,
      we fall back to the much slower unclustered allocation.
      
      To make matters worse, before the unclustered allocation, we try to
      create new block groups until we reach the 1% threshold, which
      introduces additional bitmaps and thus block groups that we'll iterate
      over at each metadata block request.
      f2d0f676
    • Li Zefan's avatar
      Btrfs: fix oops when calling statfs on readonly device · b772a86e
      Li Zefan authored
      To reproduce this bug:
      
        # dd if=/dev/zero of=img bs=1M count=256
        # mkfs.btrfs img
        # losetup -r /dev/loop1 img
        # mount /dev/loop1 /mnt
        OOPS!!
      
      It triggered BUG_ON(!nr_devices) in btrfs_calc_avail_data_space().
      
      To fix this, instead of checking write-only devices, we check all open
      deivces:
      
        # df -h /dev/loop1
        Filesystem            Size  Used Avail Use% Mounted on
        /dev/loop1            250M   28K  238M   1% /mnt
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      b772a86e
    • Mike Fleetwood's avatar
      Btrfs: Don't error on resizing FS to same size · ece7d20e
      Mike Fleetwood authored
      It seems overly harsh to fail a resize of a btrfs file system to the
      same size when a shrink or grow would succeed.  User app GParted trips
      over this error.  Allow it by bypassing the shrink or grow operation.
      Signed-off-by: default avatarMike Fleetwood <mike.fleetwood@googlemail.com>
      ece7d20e
    • Miao Xie's avatar
      Btrfs: fix deadlock on metadata reservation when evicting a inode · aa38a711
      Miao Xie authored
      When I ran the xfstests, I found the test tasks was blocked on meta-data
      reservation.
      
      By debugging, I found the reason of this bug:
         start transaction
              |
      	v
         reserve meta-data space
      	|
      	v
         flush delay allocation -> iput inode -> evict inode
      	^					|
      	|					v
         wait for delay allocation flush <- reserve meta-data space
      
      And besides that, the flush on evicting inode will block the thread, which
      is reclaiming the memory, and make oom happen easily.
      
      Fix this bug by skipping the flush step when evicting inode.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      aa38a711
    • Arnd Hannemann's avatar
      Fix URL of btrfs-progs git repository in docs · b52f75a5
      Arnd Hannemann authored
      	The location of the btrfs-progs repository has been changed.
      	This patch updates the documentation accordingly.
      Signed-off-by: default avatarArnd Hannemann <arnd@arndnet.de>
      b52f75a5
    • Dan Carpenter's avatar
      btrfs scrub: handle -ENOMEM from init_ipath() · 26bdef54
      Dan Carpenter authored
      init_ipath() can return an ERR_PTR(-ENOMEM).
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      26bdef54
  2. 21 Nov, 2011 1 commit
    • Chris Mason's avatar
      Btrfs: remove free-space-cache.c WARN during log replay · 24a70313
      Chris Mason authored
      The log replay code only partially loads block groups, since
      the block group caching code is able to detect and deal with
      extents the logging code has pinned down.
      
      While the logging code is pinning down block groups, there is
      a bogus WARN_ON we're hitting if the code wasn't able to find
      an extent in the cache.  This commit removes the warning because
      it can happen any time there isn't a valid free space cache
      for that block group.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      24a70313
  3. 20 Nov, 2011 10 commits
    • Josef Bacik's avatar
      Btrfs: sectorsize align offsets in fiemap · 4d479cf0
      Josef Bacik authored
      We've been hitting BUG()'s in btrfs_cont_expand and btrfs_fallocate and anywhere
      else that calls btrfs_get_extent while running xfstests 13 in a loop.  This is
      because fiemap is calling btrfs_get_extent with non-sectorsize aligned offsets,
      which will end up adding mappings that are not sectorsize aligned, which will
      cause problems in some cases for subsequent calls to btrfs_get_extent for
      similar areas that are sectorsize aligned.  With this patch I ran xfstests 13 in
      a loop for a couple of hours and didn't hit the problem that I could previously
      hit in at most 20 minutes.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      4d479cf0
    • Josef Bacik's avatar
      Btrfs: clear pages dirty for io and set them extent mapped · f7d61dcd
      Josef Bacik authored
      When doing the io_ctl helpers to clean up the free space cache stuff I stopped
      using our normal prepare_pages stuff, which means I of course forgot to do
      things like set the pages extent mapped, which will cause us all sorts of
      wonderful propblems.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      f7d61dcd
    • Josef Bacik's avatar
      Btrfs: wait on caching if we're loading the free space cache · 291c7d2f
      Josef Bacik authored
      We've been hitting panics when running xfstest 13 in a loop for long periods of
      time.  And actually this problem has always existed so we've been hitting these
      things randomly for a while.  Basically what happens is we get a thread coming
      into the allocator and reading the space cache off of disk and adding the
      entries to the free space cache as we go.  Then we get another thread that comes
      in and tries to allocate from that block group.  Since block_group->cached !=
      BTRFS_CACHE_NO it goes ahead and tries to do the allocation.  We do this because
      if we're doing the old slow way of caching we don't want to hold people up and
      wait for everything to finish.  The problem with this is we could end up
      discarding the space cache at some arbitrary point in the future, which means we
      could very well end up allocating space that is either bad, or when the real
      caching happens it could end up thinking the space isn't in use when it really
      is and cause all sorts of other problems.
      
      The solution is to add a new flag to indicate we are loading the free space
      cache from disk, and always try to cache the block group if cache->cached !=
      BTRFS_CACHE_FINISHED.  That way if we are loading the space cache anybody else
      who tries to allocate from the block group will have to wait until it's finished
      to make sure it completes successfully.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      291c7d2f
    • Arnd Hannemann's avatar
      Btrfs: prefix resize related printks with btrfs: · 5bb14682
      Arnd Hannemann authored
      For the user it is confusing to find something like:
      [10197.627710] new size for /dev/mapper/vg0-usr_share is 3221225472
      in kernel log, because it doesn't point directly to btrfs.
      
      This patch prefixes those messages with "btrfs:" like other btrfs
      related printks.
      Signed-off-by: default avatarArnd Hannemann <arnd@arndnet.de>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      5bb14682
    • David Sterba's avatar
      btrfs: fix stat blocks accounting · fadc0d8b
      David Sterba authored
      Round inode bytes and delalloc bytes up to real blocksize before
      converting to sector size. Otherwise eg. files smaller than 512
      are reported with zero blocks due to incorrect rounding.
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      fadc0d8b
    • Li Zefan's avatar
      Btrfs: avoid unnecessary bitmap search for cluster setup · 52621cb6
      Li Zefan authored
      setup_cluster_no_bitmap() searches all the extents and bitmaps starting
      from offset. Therefore if it returns -ENOSPC, all the bitmaps starting
      from offset are in the bitmaps list, so it's sufficient to search from
      this list in setup_cluser_bitmap().
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      52621cb6
    • Li Zefan's avatar
      Btrfs: fix to search one more bitmap for cluster setup · 0f0fbf1d
      Li Zefan authored
      Suppose there are two bitmaps [0, 256], [256, 512] and one extent
      [100, 120] in the free space cache, and we want to setup a cluster
      with offset=100, bytes=50.
      
      In this case, there will be only one bitmap [256, 512] in the temporary
      bitmaps list, and then setup_cluster_bitmap() won't search bitmap [0, 256].
      
      The cause is, the list is constructed in setup_cluster_no_bitmap(),
      and only bitmaps with bitmap_entry->offset >= offset will be added
      into the list, and the very bitmap that convers offset has
      bitmap_entry->offset <= offset.
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      0f0fbf1d
    • Jan Schmidt's avatar
      btrfs: mirror_num should be int, not u64 · 32240a91
      Jan Schmidt authored
      My previous patch introduced some u64 for failed_mirror variables, this one
      makes it consistent again.
      Signed-off-by: default avatarJan Schmidt <list.btrfs@jan-o-sch.net>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      32240a91
    • Jeff Mahoney's avatar
      btrfs: Fix up 32/64-bit compatibility for new ioctls · 745c4d8e
      Jeff Mahoney authored
       This patch casts to unsigned long before casting to a pointer and fixes
       the following warnings:
      fs/btrfs/extent_io.c:2289:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      fs/btrfs/ioctl.c:2933:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      fs/btrfs/ioctl.c:2937:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
      fs/btrfs/ioctl.c:3020:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
      fs/btrfs/scrub.c:275:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
      fs/btrfs/backref.c:686:27: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      745c4d8e
    • Chris Mason's avatar
      Btrfs: fix barrier flushes · 387125fc
      Chris Mason authored
      When btrfs is writing the super blocks, it send barrier flushes to make
      sure writeback caching drives get all the metadata on disk in the
      right order.
      
      But, we have two bugs in the way these are sent down.  When doing
      full commits (not via the tree log), we are sending the barrier down
      before the last super when it should be going down before the first.
      
      In multi-device setups, we should be waiting for the barriers to
      complete on all devices before writing any of the supers.
      
      Both of these bugs can cause corruptions on power failures.  We fix it
      with some new code to send down empty barriers to all devices before
      writing the first super.
      
      Alexandre Oliva found the multi-device bug.  Arne Jansen did the async
      barrier loop.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      Reported-by: default avatarAlexandre Oliva <oliva@lsd.ic.unicamp.br>
      387125fc
  4. 15 Nov, 2011 1 commit
    • Liu Bo's avatar
      Btrfs: fix tree corruption after multi-thread snapshots and inode_cache flush · f1ebcc74
      Liu Bo authored
      The btrfs snapshotting code requires that once a root has been
      snapshotted, we don't change it during a commit.
      
      But there are two cases to lead to tree corruptions:
      
      1) multi-thread snapshots can commit serveral snapshots in a transaction,
         and this may change the src root when processing the following pending
         snapshots, which lead to the former snapshots corruptions;
      
      2) the free inode cache was changing the roots when it root the cache,
         which lead to corruptions.
      
      This fixes things by making sure we force COW the block after we create a
      snapshot during commiting a transaction, then any changes to the roots
      will result in COW, and we get all the fs roots and snapshot roots to be
      consistent.
      Signed-off-by: default avatarLiu Bo <liubo2009@cn.fujitsu.com>
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      f1ebcc74
  5. 11 Nov, 2011 11 commits
    • David Sterba's avatar
      btrfs: rename the option to nospace_cache · 8965593e
      David Sterba authored
      Rename no_space_cache option to nospace_cache to be more consistent with
      the rest, where the simple prefix 'no' is used to negate an option.
      
      The option has been introduced during the -rc1 cycle and there are has not been
      widely used, so it's safe.
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      8965593e
    • Arne Jansen's avatar
      Btrfs: handle bio_add_page failure gracefully in scrub · 69f4cb52
      Arne Jansen authored
      Currently scrub fails with ENOMEM when bio_add_page fails. Unfortunately
      dm based targets accept only one page per bio, thus making scrub always
      fails. This patch just submits the current bio when an error is encountered
      and starts a new one.
      Signed-off-by: default avatarArne Jansen <sensille@gmx.net>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      69f4cb52
    • Miao Xie's avatar
      Btrfs: fix deadlock caused by the race between relocation · 62f30c54
      Miao Xie authored
      We can not do flushable reservation for the relocation when we create snapshot,
      because it may make the transaction commit task and the flush task wait for
      each other and the deadlock happens.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      62f30c54
    • Josef Bacik's avatar
      Btrfs: only map pages if we know we need them when reading the space cache · 2f120c05
      Josef Bacik authored
      People have been running into a warning when loading space cache because the
      page is already mapped when trying to read in a bitmap.  The way we read in
      entries and pages is kind of convoluted, so fix it so that io_ctl_read_entry
      maps the entries if it needs to, and if it hits the end of the page it simply
      unmaps the page.  That way we can unconditionally unmap the io_ctl before
      reading in the bitmap and we should stop hitting these warnings.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      2f120c05
    • Miao Xie's avatar
      Btrfs: fix orphan backref nodes · 76b9e23d
      Miao Xie authored
      If the root node of a fs/file tree is in the block group that is
      being relocated, but the others are not in the other block groups.
      when we create a snapshot for this tree between the relocation tree
      creation ends and ->create_reloc_tree is set to 0, Btrfs will create
      some backref nodes that are the lowest nodes of the backrefs cache.
      But we forget to add them into ->leaves list of the backref cache
      and deal with them, and at last, they will triggered BUG_ON().
      
        kernel BUG at fs/btrfs/relocation.c:239!
      
      This patch fixes it by adding them into ->leaves list of backref cache.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      76b9e23d
    • Miao Xie's avatar
      Btrfs: Abstract similar code for btrfs_block_rsv_add{, _noflush} · 61b520a9
      Miao Xie authored
      btrfs_block_rsv_add{, _noflush}() have similar code, so abstract that code.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      61b520a9
    • Miao Xie's avatar
      Btrfs: fix unreleased path in btrfs_orphan_cleanup() · 3254c876
      Miao Xie authored
      When we did stress test for the space relocation, the deadlock happened.
      By debugging, We found it was caused by the carelessness that we forgot
      to unlock the read lock of the extent buffers in btrfs_orphan_cleanup()
      before we end the transaction handle, so the transaction commit task waited
      the task, which called btrfs_orphan_cleanup(), to unlock the extent buffer,
      but that task waited the commit task to end the transaction commit, and
      the deadlock happened. Fix it.
      Signed-ff-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      3254c876
    • Miao Xie's avatar
      Btrfs: fix no reserved space for writing out inode cache · ba38eb4d
      Miao Xie authored
      I-node cache forgets to reserve the space when writing out it. And when
      we do some stress test, such as synctest, it will trigger WARN_ON() in
      use_block_rsv().
      
      WARNING: at fs/btrfs/extent-tree.c:5718 btrfs_alloc_free_block+0xbf/0x281 [btrfs]()
      ...
      Call Trace:
       [<ffffffff8104df86>] warn_slowpath_common+0x80/0x98
       [<ffffffff8104dfb3>] warn_slowpath_null+0x15/0x17
       [<ffffffffa0369c60>] btrfs_alloc_free_block+0xbf/0x281 [btrfs]
       [<ffffffff810cbcb8>] ? __set_page_dirty_nobuffers+0xfe/0x108
       [<ffffffffa035c040>] __btrfs_cow_block+0x118/0x3b5 [btrfs]
       [<ffffffffa035c7ba>] btrfs_cow_block+0x103/0x14e [btrfs]
       [<ffffffffa035e4c4>] btrfs_search_slot+0x249/0x6a4 [btrfs]
       [<ffffffffa036d086>] btrfs_lookup_inode+0x2a/0x8a [btrfs]
       [<ffffffffa03788b7>] btrfs_update_inode+0xaa/0x141 [btrfs]
       [<ffffffffa036d7ec>] btrfs_save_ino_cache+0xea/0x202 [btrfs]
       [<ffffffffa03a761e>] ? btrfs_update_reloc_root+0x17e/0x197 [btrfs]
       [<ffffffffa0373867>] commit_fs_roots+0xaa/0x158 [btrfs]
       [<ffffffffa03746a6>] btrfs_commit_transaction+0x405/0x731 [btrfs]
       [<ffffffff810690df>] ? wake_up_bit+0x25/0x25
       [<ffffffffa039d652>] ? btrfs_log_dentry_safe+0x43/0x51 [btrfs]
       [<ffffffffa0381c5f>] btrfs_sync_file+0x16a/0x198 [btrfs]
       [<ffffffff81122806>] ? mntput+0x21/0x23
       [<ffffffff8112d150>] vfs_fsync_range+0x18/0x21
       [<ffffffff8112d170>] vfs_fsync+0x17/0x19
       [<ffffffff8112d316>] do_fsync+0x29/0x3e
       [<ffffffff8112d348>] sys_fsync+0xb/0xf
       [<ffffffff81468352>] system_call_fastpath+0x16/0x1b
      
      Sometimes it causes BUG_ON() in the reservation code of the delayed inode
      is triggered.
      
      So we must reserve enough space for inode cache.
      
      Note: If we can not reserve the enough space for inode cache, we will
      give up writing out it.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      ba38eb4d
    • Miao Xie's avatar
      Btrfs: fix nocow when deleting the item · 924cd8fb
      Miao Xie authored
      btrfs_previous_item() just search the b+ tree, do not COW the nodes or leaves,
      if we modify the result of it, the meta-data will be broken. fix it.
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      924cd8fb
    • Chris Mason's avatar
    • Chris Mason's avatar
      Btrfs: tweak the delayed inode reservations again · 2115133f
      Chris Mason authored
      Josef sent along an incremental to the inode reservation
      code to make sure we try and fall back to directly updating
      the inode item if things go horribly wrong.
      
      This reworks that patch slightly, adding a fallback function
      that will always try to update the inode item directly without
      going through the delayed_inode code.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      2115133f
  6. 09 Nov, 2011 5 commits
  7. 08 Nov, 2011 2 commits
    • Josef Bacik's avatar
      Btrfs: fix our reservations for updating an inode when completing io · 7fd2ae21
      Josef Bacik authored
      People have been reporting ENOSPC crashes in finish_ordered_io.  This is because
      we try to steal from the delalloc block rsv to satisfy a reservation to update
      the inode.  The problem with this is we don't explicitly save space for updating
      the inode when doing delalloc.  This is kind of a problem and we've gotten away
      with this because way back when we just stole from the delalloc reserve without
      any questions, and this worked out fine because generally speaking the leaf had
      been modified either by the mtime update when we did the original write or
      because we just updated the leaf when we inserted the file extent item, only on
      rare occasions had the leaf not actually been modified, and that was still ok
      because we'd just use a block or two out of the over-reservation that is
      delalloc.
      
      Then came the delayed inode stuff.  This is amazing, except it wants a full
      reservation for updating the inode since it may do it at some point down the
      road after we've written the blocks and we have to recow everything again.  This
      worked out because the delayed inode stuff just stole from the global reserve,
      that is until recently when I changed that because it caused other problems.
      
      So here we are, we're doing everything right and being screwed for it.  So take
      an extra reservation for the inode at delalloc reservation time and carry it
      through the life of the delalloc reservation.  If we need it we can steal it in
      the delayed inode stuff.  If we have already stolen it try and do a normal
      metadata reservation.  If that fails try to steal from the delalloc reservation.
      If _that_ fails we'll get a WARN_ON() so I can start thinking of a better way to
      solve this and in the meantime we'll steal from the global reserve.
      
      With this patch I ran xfstests 13 in a loop for a couple of hours and didn't see
      any problems.
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      7fd2ae21
    • Chris Mason's avatar
      Btrfs: fix oops on NULL trans handle in btrfs_truncate · 917c16b2
      Chris Mason authored
      If we fail to reserve space in the transaction during truncate, we can
      error out with a NULL trans handle.  The cleanup code needs an extra
      check to make sure we aren't trying to use the bad handle.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      917c16b2
  8. 07 Nov, 2011 1 commit
    • slyich@gmail.com's avatar
      btrfs: fix double-free 'tree_root' in 'btrfs_mount()' · 45ea6095
      slyich@gmail.com authored
      On error path 'tree_root' is treed in 'free_fs_info()'.
      No need to free it explicitely. Noticed by SLUB in debug mode:
      
      Complete reproducer under usermode linux (discovered on real
      machine):
      
          bdev=/dev/ubda
          btr_root=/btr
          /mkfs.btrfs $bdev
          mount $bdev $btr_root
          mkdir $btr_root/subvols/
          cd $btr_root/subvols/
          /btrfs su cr foo
          /btrfs su cr bar
          mount $bdev -osubvol=subvols/foo $btr_root/subvols/bar
          umount $btr_root/subvols/bar
      
      which gives
      
      device fsid 4d55aa28-45b1-474b-b4ec-da912322195e devid 1 transid 7 /dev/ubda
      =============================================================================
      BUG kmalloc-2048: Object already free
      -----------------------------------------------------------------------------
      
      INFO: Allocated in btrfs_mount+0x389/0x7f0 age=0 cpu=0 pid=277
      INFO: Freed in btrfs_mount+0x51c/0x7f0 age=0 cpu=0 pid=277
      INFO: Slab 0x0000000062886200 objects=15 used=9 fp=0x0000000070b4d2d0 flags=0x4081
      INFO: Object 0x0000000070b4d2d0 @offset=21200 fp=0x0000000070b4a968
      ...
      Call Trace:
      70b31948:  [<6008c522>] print_trailer+0xe2/0x130
      70b31978:  [<6008c5aa>] object_err+0x3a/0x50
      70b319a8:  [<6008e242>] free_debug_processing+0x142/0x2a0
      70b319e0:  [<600ebf6f>] btrfs_mount+0x55f/0x7f0
      70b319f8:  [<6008e5c1>] __slab_free+0x221/0x2d0
      Signed-off-by: default avatarSergei Trofimovich <slyfox@gentoo.org>
      Cc: Arne Jansen <sensille@gmx.net>
      Cc: Chris Mason <chris.mason@oracle.com>
      Cc: David Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      45ea6095