ext4: don't mark mmp buffer head dirty
authorLi Dongyang <dongyangli@ddn.com>
Sat, 15 Sep 2018 21:11:25 +0000 (17:11 -0400)
committerTheodore Ts'o <tytso@mit.edu>
Sat, 15 Sep 2018 21:11:25 +0000 (17:11 -0400)
commitfe18d649891d813964d3aaeebad873f281627fbc
tree9ff37bdb4d0eaff78f8ddd0ad4e9e68d48f21e36
parent338affb548c243d2af25b1ca628e67819350de6b
ext4: don't mark mmp buffer head dirty

Marking mmp bh dirty before writing it will make writeback
pick up mmp block later and submit a write, we don't want the
duplicate write as kmmpd thread should have full control of
reading and writing the mmp block.
Another reason is we will also have random I/O error on
the writeback request when blk integrity is enabled, because
kmmpd could modify the content of the mmp block(e.g. setting
new seq and time) while the mmp block is under I/O requested
by writeback.

Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: stable@vger.kernel.org
fs/ext4/mmp.c