ext4: add lockdep annotations for i_data_sem
authorTheodore Ts'o <tytso@mit.edu>
Fri, 1 Apr 2016 05:31:28 +0000 (01:31 -0400)
committerSasha Levin <sasha.levin@oracle.com>
Wed, 20 Apr 2016 05:03:43 +0000 (01:03 -0400)
commit031b34ddc5b7714d957f7e8ed229e1c1a4c22a8f
tree175e475070909ad47fb33fd2054f4e4cae5a2ec5
parent9dcc54b46e2c231877dfdf28f883789925985891
ext4: add lockdep annotations for i_data_sem

[ Upstream commit daf647d2dd58cec59570d7698a45b98e580f2076 ]

With the internal Quota feature, mke2fs creates empty quota inodes and
quota usage tracking is enabled as soon as the file system is mounted.
Since quotacheck is no longer preallocating all of the blocks in the
quota inode that are likely needed to be written to, we are now seeing
a lockdep false positive caused by needing to allocate a quota block
from inside ext4_map_blocks(), while holding i_data_sem for a data
inode.  This results in this complaint:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&ei->i_data_sem);
                                lock(&s->s_dquot.dqio_mutex);
                                lock(&ei->i_data_sem);
   lock(&s->s_dquot.dqio_mutex);

Google-Bug-Id: 27907753

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
fs/ext4/ext4.h
fs/ext4/move_extent.c
fs/ext4/super.c