ocfs2: free up write context when direct IO failed

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>

2 files changed, 19 insertions, 2 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index da578ad4c08f..eb1ce30412dc 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2411,8 +2411,16 @@ static int ocfs2_dio_end_io(struct kiocb *iocb,
         /* 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);
 
diff --git a/fs/ocfs2/cluster/masklog.h b/fs/ocfs2/cluster/masklog.h
index 308ea0eb35fd..a396096a5099 100644
--- 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 &&                     \