1. 12 Dec, 2013 4 commits
    • Wang Shilong's avatar
      Btrfs: fix an oops when doing balance relocation · c974c464
      Wang Shilong authored
      I hit an oops when inserting reloc root into @reloc_root_tree(it can be
      easily triggered when forcing cow for relocation root)
      
      [  866.494539]  [<ffffffffa0499579>] btrfs_init_reloc_root+0x79/0xb0 [btrfs]
      [  866.495321]  [<ffffffffa044c240>] record_root_in_trans+0xb0/0x110 [btrfs]
      [  866.496109]  [<ffffffffa044d758>] btrfs_record_root_in_trans+0x48/0x80 [btrfs]
      [  866.496908]  [<ffffffffa0494da8>] select_reloc_root+0xa8/0x210 [btrfs]
      [  866.497703]  [<ffffffffa0495c8a>] do_relocation+0x16a/0x540 [btrfs]
      
      This is because reloc root inserted into @reloc_root_tree is not within one
      transaction,reloc root may be cowed and root block bytenr will be reused then
      oops happens.We should update reloc root in @reloc_root_tree when cow reloc
      root node, fix it.
      Signed-off-by: default avatarWang Shilong <wangsl.fnst@cn.fujitsu.com>
      Reviewed-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      c974c464
    • Filipe David Borba Manana's avatar
      Btrfs: don't miss skinny extent items on delayed ref head contention · 639eefc8
      Filipe David Borba Manana authored
      Currently extent-tree.c:btrfs_lookup_extent_info() can miss the lookup
      of skinny extent items. This can happen when the execution flow is the
      following:
      
      * We do an extent tree lookup and fail to find a skinny extent item;
      
      * As a result, we attempt to see if a non-skinny extent item exists,
        either by looking at previous item in the leaf or by doing another
        full extent tree search;
      
      * We have a transaction and then we check for a matching delayed ref
        head in the transaction's delayed refs rbtree;
      
      * We find such delayed ref head and then we try to lock it with a
        call to mutex_trylock();
      
      * The lock was contended so we jump to the label "again", which repeats
        the extent tree search but for a non-skinny extent item, because we set
        previously metadata variable to 0 and the search key to look for a
        non-skinny extent-item;
      
      * After the jump (and after releasing the transaction's delayed refs
        lock), a skinny extent item might have been added to the extent tree
        but we will miss it because metadata is set to 0 and the search key
        is set for a non-skinny extent-item.
      
      The fix here is to not reset metadata to 0 and to jump to the initial search
      key setup if the delayed ref head is contended, instead of jumping directly
      to the extent tree search label ("again").
      
      This issue was found while investigating the issue reported at Bugzilla 64961.
      
      David Sterba suspected this function was missing extent items, and that
      this could be caused by the last change to this function, which was made
      in the following patch:
      
          [PATCH] Btrfs: optimize btrfs_lookup_extent_info()
          (commit 74be9510)
      
      But in fact this issue already existed before, because after failing to find
      a skinny extent item, the code set the search key for a non-skinny extent
      item, and on contention of a matching delayed ref head it would not search
      the extent tree for a skinny extent item anymore.
      Signed-off-by: default avatarFilipe David Borba Manana <fdmanana@gmail.com>
      Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      639eefc8
    • David Sterba's avatar
      btrfs: call mnt_drop_write after interrupted subvol deletion · e43f998e
      David Sterba authored
      If btrfs_ioctl_snap_destroy blocks on the mutex and the process is
      killed, mnt_write count is unbalanced and leads to unmountable
      filesystem.
      
      CC: stable@vger.kernel.org
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      e43f998e
    • Miao Xie's avatar
      Btrfs: don't clear the default compression type · a7e252af
      Miao Xie authored
      We met a oops caused by the wrong compression type:
      [  556.512356] BUG: unable to handle kernel NULL pointer dereference at           (null)
      [  556.512370] IP: [<ffffffff811dbaa0>] __list_del_entry+0x1/0x98
      [SNIP]
      [  556.512490]  [<ffffffff811dbb44>] ? list_del+0xd/0x2b
      [  556.512539]  [<ffffffffa05dd5ce>] find_workspace+0x97/0x175 [btrfs]
      [  556.512546]  [<ffffffff813c14b5>] ? _raw_spin_lock+0xe/0x10
      [  556.512576]  [<ffffffffa05de276>] btrfs_compress_pages+0x2d/0xa2 [btrfs]
      [  556.512601]  [<ffffffffa05af060>] compress_file_range.constprop.54+0x1f2/0x4e8 [btrfs]
      [  556.512627]  [<ffffffffa05af388>] async_cow_start+0x32/0x4d [btrfs]
      [  556.512655]  [<ffffffffa05cc7a1>] worker_loop+0x144/0x4c3 [btrfs]
      [  556.512661]  [<ffffffff81059404>] ? finish_task_switch+0x80/0xb8
      [  556.512689]  [<ffffffffa05cc65d>] ? btrfs_queue_worker+0x244/0x244 [btrfs]
      [  556.512695]  [<ffffffff8104fa4e>] kthread+0x8d/0x95
      [  556.512699]  [<ffffffff81050000>] ? bit_waitqueue+0x34/0x7d
      [  556.512704]  [<ffffffff8104f9c1>] ? __kthread_parkme+0x65/0x65
      [  556.512709]  [<ffffffff813c7eec>] ret_from_fork+0x7c/0xb0
      [  556.512713]  [<ffffffff8104f9c1>] ? __kthread_parkme+0x65/0x65
      
      Steps to reproduce:
       # mkfs.btrfs -f <dev>
       # mount -o nodatacow <dev> <mnt>
       # touch <mnt>/<file>
       # chattr =c <mnt>/<file>
       # dd if=/dev/zero of=<mnt>/<file> bs=1M count=10
      
      It is because we cleared the default compression type when setting the
      nodatacow. In fact, we needn't do it because we have used COMPRESS flag to
      indicate if we need compressed the file data or not, needn't use the
      variant -- compress_type -- in btrfs_info to do the same thing, and just
      use it to hold the default compression type. Or we would get a wrong compress
      type for a file whose own compress flag is set but the compress flag of its
      filesystem is not set.
      Reported-by: default avatarTsutomu Itoh <t-itoh@jp.fujitsu.com>
      Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
      Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      a7e252af
  2. 04 Dec, 2013 1 commit
  3. 21 Nov, 2013 18 commits
  4. 15 Nov, 2013 2 commits
  5. 12 Nov, 2013 15 commits