2006-12-07 04:39:33

by Andrew Morton

[permalink] [raw]
Subject: [patch 272/354] jbd2: wait for already submitted t_sync_datalist buffer to complete

From: Hisashi Hifumi <[email protected]>

In the current jbd code, if a buffer on BJ_SyncData list is dirty and not
locked, the buffer is refiled to BJ_Locked list, submitted to the IO and
waited for IO completion.

But the fsstress test showed the case that when a buffer was already
submitted to the IO just before the buffer_dirty(bh) check, the buffer was
not waited for IO completion.

Following patch solves this problem. If it is assumed that a buffer is
submitted to the IO before the buffer_dirty(bh) check and still being
written to disk, this buffer is refiled to BJ_Locked list.

Signed-off-by: Hisashi Hifumi <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: "Stephen C. Tweedie" <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

fs/jbd2/commit.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff -puN fs/jbd2/commit.c~jbd2-wait-for-already-submitted-t_sync_datalist-buffer fs/jbd2/commit.c
--- a/fs/jbd2/commit.c~jbd2-wait-for-already-submitted-t_sync_datalist-buffer
+++ a/fs/jbd2/commit.c
@@ -248,8 +248,12 @@ write_out_data:
bufs = 0;
goto write_out_data;
- }
- else {
+ } else if (!locked && buffer_locked(bh)) {
+ __jbd2_journal_file_buffer(jh, commit_transaction,
+ BJ_Locked);
+ jbd_unlock_bh_state(bh);
+ put_bh(bh);
+ } else {
BUFFER_TRACE(bh, "writeout complete: unfile");