ocfs2: cancel dqi_sync_work before freeing oinfo

ocfs2_global_read_info() will initialize and schedule dqi_sync_work at the
end, if error occurs after successfully reading global quota, it will
trigger the following warning with CONFIG_DEBUG_OBJECTS_* enabled:

ODEBUG: free active (active state 0) object: 00000000d8b0ce28 object type: timer_list hint: qsync_work_fn+0x0/0x16c

This reports that there is an active delayed work when freeing oinfo in
error handling, so cancel dqi_sync_work first.  BTW, return status instead
of -1 when .read_file_info fails.

Link: https://syzkaller.appspot.com/bug?extid=f7af59df5d6b25f0febd
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 171bf93 ("ocfs2: Periodic quota syncing")
Signed-off-by: Joseph Qi <[email protected]>
Reviewed-by: Heming Zhao <[email protected]>
Reported-by: [email protected]
Tested-by: [email protected]
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: josephhz

fs/ocfs2/quota_local.c

@@ -692,14 +692,15 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	int status;
 	struct buffer_head *bh = NULL;
 	struct ocfs2_quota_recovery *rec;
-	int locked = 0;
+	int locked = 0, global_read = 0;
 
 	info->dqi_max_spc_limit = 0x7fffffffffffffffLL;
 	info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
 	oinfo = kmalloc(sizeof(struct ocfs2_mem_dqinfo), GFP_NOFS);
 	if (!oinfo) {
 		mlog(ML_ERROR, "failed to allocate memory for ocfs2 quota"
 			       " info.");
+		status = -ENOMEM;
 		goto out_err;
 	}
 	info->dqi_priv = oinfo;
@@ -712,6 +713,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	status = ocfs2_global_read_info(sb, type);
 	if (status < 0)
 		goto out_err;
+	global_read = 1;
 
 	status = ocfs2_inode_lock(lqinode, &oinfo->dqi_lqi_bh, 1);
 	if (status < 0) {
@@ -782,10 +784,12 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 		if (locked)
 			ocfs2_inode_unlock(lqinode, 1);
 		ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);
+		if (global_read)
+			cancel_delayed_work_sync(&oinfo->dqi_sync_work);
 		kfree(oinfo);
 	}
 	brelse(bh);
-	return -1;
+	return status;
 }
 
 /* Write local info to quota file */