On Mon, 24 Aug 2015 15:39:04 +0800 Junxiao Bi <junxiao...@oracle.com> wrote:
> On 08/24/2015 03:23 PM, Ryan Ding wrote:
> > Orabug: 21612107
> >
> > Use wrong return value in ocfs2_file_write_iter(). This will cause
> > ocfs2_rw_unlock() be called both in write_iter & end_io, and trigger a
> > BUG_ON.
> >
> > This issue exist since commit 7da839c475894ea872ec909a5d2e83dddccff5be.
> Better say:
> This issue is introduced by commit 7da839c47589 ("ocfs2: use
> __generic_file_write_iter()") , or checkpatch will report a style error.
> Other looks good.
>
> Reviewed-by: Junxiao Bi <junxiao...@oracle.com>
>
Also we've recently adopted the convention of using the "Fixes:" tag:
Fixes: 7da839c47589 ("ocfs2: use __generic_file_write_iter()")
And as the patch fixes a regression we should add the "Cc:
<sta...@vger.kernel.org>" tag.
And we should the author of the bad patch for review (hi, Al).
I've made these changes and I'll get this patch into Linus this week,
for 4.2.
From: Ryan Ding <ryan.d...@oracle.com>
Subject: ocfs2: direct write will call ocfs2_rw_unlock() twice when doing
aio+dio
Orabug: 21612107
ocfs2_file_write_iter() is usng the wrong return value ('written'). This
will cause ocfs2_rw_unlock() be called both in write_iter & end_io,
triggering a BUG_ON.
This issue was introduced by commit 7da839c47589 ("ocfs2: use
__generic_file_write_iter()").
Fixes: 7da839c47589 ("ocfs2: use __generic_file_write_iter()")
Signed-off-by: Ryan Ding <ryan.d...@oracle.com>
Reviewed-by: Junxiao Bi <junxiao...@oracle.com>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Cc: Mark Fasheh <mfas...@suse.com>
Cc: Joel Becker <jl...@evilplan.org>
Cc: <sta...@vger.kernel.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
---
fs/ocfs2/file.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff -puN
fs/ocfs2/file.c~ocfs2-direct-write-will-call-ocfs2_rw_unlock-twice-when-doing-aiodio
fs/ocfs2/file.c
---
a/fs/ocfs2/file.c~ocfs2-direct-write-will-call-ocfs2_rw_unlock-twice-when-doing-aiodio
+++ a/fs/ocfs2/file.c
@@ -2366,6 +2366,20 @@ relock:
/* buffered aio wouldn't have proper lock coverage today */
BUG_ON(written == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT));
+ /*
+ * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
+ * function pointer which is called when o_direct io completes so that
+ * it can unlock our rw lock.
+ * Unfortunately there are error cases which call end_io and others
+ * that don't. so we don't have to unlock the rw_lock if either an
+ * async dio is going to do it in the future or an end_io after an
+ * error has already done it.
+ */
+ if ((written == -EIOCBQUEUED) || (!ocfs2_iocb_is_rw_locked(iocb))) {
+ rw_level = -1;
+ unaligned_dio = 0;
+ }
+
if (unlikely(written <= 0))
goto no_sync;
@@ -2390,20 +2404,6 @@ relock:
}
no_sync:
- /*
- * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
- * function pointer which is called when o_direct io completes so that
- * it can unlock our rw lock.
- * Unfortunately there are error cases which call end_io and others
- * that don't. so we don't have to unlock the rw_lock if either an
- * async dio is going to do it in the future or an end_io after an
- * error has already done it.
- */
- if ((ret == -EIOCBQUEUED) || (!ocfs2_iocb_is_rw_locked(iocb))) {
- rw_level = -1;
- unaligned_dio = 0;
- }
-
if (unaligned_dio && ocfs2_iocb_is_unaligned_aio(iocb)) {
ocfs2_iocb_clear_unaligned_aio(iocb);
mutex_unlock(&OCFS2_I(inode)->ip_unaligned_aio);
_
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