jbd2: use GFP_NOFS for blkdev_issue_flush (99aa7846) · Commits · 戴 / test

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> Cc: stable@vger.kernel.org

fs/jbd2/commit.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)

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