Zheng Liu 4bd809dbbf ext4: don't take the i_mutex lock when doing DIO overwrites
Aligned and overwrite direct I/O can be parallelized.  In
ext4_file_dio_write, we first check whether these conditions are
satisfied or not.  If so, we take i_data_sem and release i_mutex lock
directly.  Meanwhile iocb->private is set to indicate that this is a
dio overwrite, and it will be handled in ext4_ext_direct_IO.

[ Added fix from Dan Carpenter to fix locking bug on the error path. ]

CC: Tao Ma <tm@tao.ma>
CC: Eric Sandeen <sandeen@redhat.com>
CC: Robin Dong <hao.bigrat@gmail.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-07-22 20:19:31 -04:00
..
2011-07-25 14:30:23 -04:00
2012-04-29 18:47:10 -04:00