1. 14 Jun, 2013 38 commits
  2. 08 Jun, 2013 2 commits
    • Josef Bacik's avatar
      Btrfs: stop all workers before cleaning up roots · 13e6c37b
      Josef Bacik authored
      Dave reported a panic because the extent_root->commit_root was NULL in the
      caching kthread.  That is because we just unset it in free_root_pointers, which
      is not the correct thing to do, we have to either wait for the caching kthread
      to complete or hold the extent_commit_sem lock so we know the thread has exited.
      This patch makes the kthreads all stop first and then we do our cleanup.  This
      should fix the race.  Thanks,
      Reported-by: default avatarDavid Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
      13e6c37b
    • Liu Bo's avatar
      Btrfs: fix use-after-free bug during umount · 2932505a
      Liu Bo authored
      Commit be283b2e
      (    Btrfs: use helper to cleanup tree roots) introduced the following bug,
      
       BUG: unable to handle kernel NULL pointer dereference at 0000000000000034
       IP: [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
      [...]
       Pid: 2463, comm: btrfs-cache-1 Tainted: G           O 3.9.0+ #4 innotek GmbH VirtualBox/VirtualBox
       RIP: 0010:[<ffffffffa039368c>]  [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
       Process btrfs-cache-1 (pid: 2463, threadinfo ffff880112d60000, task ffff880117679730)
      [...]
       Call Trace:
        [<ffffffffa0398a99>] btrfs_search_slot+0x104/0x64d [btrfs]
        [<ffffffffa039aea4>] btrfs_next_old_leaf+0xa7/0x334 [btrfs]
        [<ffffffffa039b141>] btrfs_next_leaf+0x10/0x12 [btrfs]
        [<ffffffffa039ea13>] caching_thread+0x1a3/0x2e0 [btrfs]
        [<ffffffffa03d8811>] worker_loop+0x14b/0x48e [btrfs]
        [<ffffffffa03d86c6>] ? btrfs_queue_worker+0x25c/0x25c [btrfs]
        [<ffffffff81068d3d>] kthread+0x8d/0x95
        [<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43
        [<ffffffff8151e5ac>] ret_from_fork+0x7c/0xb0
        [<ffffffff81068cb0>] ? kthread_freezable_should_stop+0x43/0x43
      RIP  [<ffffffffa039368c>] extent_buffer_get+0x4/0xa [btrfs]
      
      We've free'ed commit_root before actually getting to free block groups where
      caching thread needs valid extent_root->commit_root.
      Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
      Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
      Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
      2932505a