2006-11-29 08:21:17

by Hisashi Hifumi

[permalink] [raw]
Subject: [PATCH] jbd: wait for already submitted t_sync_datalist buffer to complete

Hi.

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.

Thanks.

Signed-off-by :Hisashi Hifumi <[email protected]>

--- linux-2.6.19-rc6.org/fs/jbd/commit.c 2006-11-28 17:10:01.000000000 +0900
+++ linux-2.6.19-rc6/fs/jbd/commit.c 2006-11-29 14:51:09.000000000 +0900
@@ -248,8 +248,12 @@ write_out_data:
bufs = 0;
goto write_out_data;
}
- }
- else {
+ } else if (!locked && buffer_locked(bh)) {
+ __journal_file_buffer(jh, commit_transaction,
+ BJ_Locked);
+ jbd_unlock_bh_state(bh);
+ put_bh(bh);
+ } else {
BUFFER_TRACE(bh, "writeout complete: unfile");
__journal_unfile_buffer(jh);
jbd_unlock_bh_state(bh);