[ 026/167] [PATCH] jbd2: use GFP_NOFS for blkdev_issue_flush

Ben Hutchings
2012-05-09T06:18:48Z

From: Shaohua Li <shli@kernel.org>

commit 99aa78466777083255b876293e9e83dec7cd809a upstream.

flush request is issued in transaction commit code path, so looks using
GFP_KERNEL to allocate memory for flush request bio falls into the classic
deadlock issue. I saw btrfs and dm get it right, but ext4, xfs and md are
using GFP.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/jbd2/commit.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 806525a..840f70f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -723,7 +723,7 @@ start_journal_io:
if (commit_transaction->t_need_data_flush &&
(journal->j_fs_dev != journal->j_dev) &&
(journal->j_flags & JBD2_BARRIER))
- blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
+ blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);

/* Done it all: now write the commit record asynchronously. */
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
@@ -859,7 +859,7 @@ wait_for_iobuf:
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
journal->j_flags & JBD2_BARRIER) {
- blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL);
+ blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
}

if (err)
--
1.7.10