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Message-Id: <20170106141107.23953-7-mhocko@kernel.org> Date: Fri, 6 Jan 2017 15:11:05 +0100 From: Michal Hocko <mhocko@...nel.org> To: <linux-mm@...ck.org>, <linux-fsdevel@...r.kernel.org> Cc: Andrew Morton <akpm@...ux-foundation.org>, Dave Chinner <david@...morbit.com>, djwong@...nel.org, "Theodore Ts'o" <tytso@....edu>, Chris Mason <clm@...com>, David Sterba <dsterba@...e.cz>, Jan Kara <jack@...e.cz>, ceph-devel@...r.kernel.org, cluster-devel@...hat.com, linux-nfs@...r.kernel.org, logfs@...fs.org, linux-xfs@...r.kernel.org, linux-ext4@...r.kernel.org, linux-btrfs@...r.kernel.org, linux-mtd@...ts.infradead.org, reiserfs-devel@...r.kernel.org, linux-ntfs-dev@...ts.sourceforge.net, linux-f2fs-devel@...ts.sourceforge.net, linux-afs@...ts.infradead.org, LKML <linux-kernel@...r.kernel.org>, Michal Hocko <mhocko@...e.com> Subject: [PATCH 6/8] jbd2: make the whole kjournald2 kthread NOFS safe From: Michal Hocko <mhocko@...e.com> kjournald2 is central to the transaction commit processing. As such any potential allocation from this kernel thread has to be GFP_NOFS. Make sure to mark the whole kernel thread GFP_NOFS by the memalloc_nofs_save. Suggested-by: Jan Kara <jack@...e.cz> Signed-off-by: Michal Hocko <mhocko@...e.com> Reviewed-by: Jan Kara <jack@...e.cz> --- fs/jbd2/journal.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index a097048ed1a3..3a449150f834 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -206,6 +206,13 @@ static int kjournald2(void *arg) wake_up(&journal->j_wait_done_commit); /* + * Make sure that no allocations from this kernel thread will ever recurse + * to the fs layer because we are responsible for the transaction commit + * and any fs involvement might get stuck waiting for the trasn. commit. + */ + memalloc_nofs_save(); + + /* * And now, wait forever for commit wakeup events. */ write_lock(&journal->j_state_lock); -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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