[PATCH 4.14 057/124] ocfs2: free up write context when direct IO failed

Greg Kroah-Hartman
2018-11-19T16:49:18Z

From: Wengang Wang <wen.gang.wang@oracle.com>

commit 5040f8df56fb90c7919f1c9b0b6e54c843437456 upstream.

The write context should also be freed even when direct IO failed.
Otherwise a memory leak is introduced and entries remain in
oi->ip_unwritten_list causing the following BUG later in unlink path:

ERROR: bug expression: !list_empty(&oi->ip_unwritten_list)
ERROR: Clear inode of 215043, inode has unwritten extents
...
Call Trace:
? __set_current_blocked+0x42/0x68
ocfs2_evict_inode+0x91/0x6a0 [ocfs2]
? bit_waitqueue+0x40/0x33
evict+0xdb/0x1af
iput+0x1a2/0x1f7
do_unlinkat+0x194/0x28f
SyS_unlinkat+0x1b/0x2f
do_syscall_64+0x79/0x1ae
entry_SYSCALL_64_after_hwframe+0x151/0x0

This patch also logs, with frequency limit, direct IO failures.

Link: http://lkml.kernel.org/r/20181102170632.25921-1-wen.gang.wang@oracle.com
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Changwei Ge <ge.changwei@h3c.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ocfs2/aops.c | 12 ++++++++++--
fs/ocfs2/cluster/masklog.h | 9 +++++++++
2 files changed, 19 insertions(+), 2 deletions(-)

--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2404,8 +2404,16 @@ static int ocfs2_dio_end_io(struct kiocb
/* this io's submitter should not have unlocked this before we could */
BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));

- if (bytes > 0 && private)
- ret = ocfs2_dio_end_io_write(inode, private, offset, bytes);
+ if (bytes <= 0)
+ mlog_ratelimited(ML_ERROR, "Direct IO failed, bytes = %lld",
+ (long long)bytes);
+ if (private) {
+ if (bytes > 0)
+ ret = ocfs2_dio_end_io_write(inode, private, offset,
+ bytes);
+ else
+ ocfs2_dio_free_write_ctx(inode, private);
+ }

ocfs2_iocb_clear_rw_locked(iocb);

--- a/fs/ocfs2/cluster/masklog.h
+++ b/fs/ocfs2/cluster/masklog.h
@@ -178,6 +178,15 @@ do { \
##__VA_ARGS__); \
} while (0)

+#define mlog_ratelimited(mask, fmt, ...) \
+do { \
+ static DEFINE_RATELIMIT_STATE(_rs, \
+ DEFAULT_RATELIMIT_INTERVAL, \
+ DEFAULT_RATELIMIT_BURST); \
+ if (__ratelimit(&_rs)) \
+ mlog(mask, fmt, ##__VA_ARGS__); \
+} while (0)
+
#define mlog_errno(st) ({ \
int _st = (st); \
if (_st != -ERESTARTSYS && _st != -EINTR && \