---

yaml
---
r: 339437
b: refs/heads/master
c: cfb0285
h: refs/heads/master
i:
  339435: e5cc1e7
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: da6958c873ecd846d71fafbfe0f6168bb9c2c99e
+refs/heads/master: cfb02852226aa449fe27075caffe88726507668c

trunk/fs/xfs/xfs_buf.c

@@ -569,7 +569,9 @@ _xfs_buf_find(
 	 */
 	if (bp->b_flags & XBF_STALE) {
 		ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
+		ASSERT(bp->b_iodone == NULL);
 		bp->b_flags &= _XBF_KMEM | _XBF_PAGES;
+		bp->b_pre_io = NULL;
 	}
 
 	trace_xfs_buf_find(bp, flags, _RET_IP_);
@@ -1323,6 +1325,20 @@ _xfs_buf_ioapply(
 	/* we only use the buffer cache for meta-data */
 	rw |= REQ_META;
 
+	/*
+	 * run the pre-io callback function if it exists. If this function
+	 * fails it will mark the buffer with an error and the IO should
+	 * not be dispatched.
+	 */
+	if (bp->b_pre_io) {
+		bp->b_pre_io(bp);
+		if (bp->b_error) {
+			xfs_force_shutdown(bp->b_target->bt_mount,
+					   SHUTDOWN_CORRUPT_INCORE);
+			return;
+		}
+	}
+
 	/*
 	 * Walk all the vectors issuing IO on them. Set up the initial offset
 	 * into the buffer and the desired IO size before we start -

trunk/fs/xfs/xfs_buf.h

@@ -155,6 +155,9 @@ typedef struct xfs_buf {
 	unsigned int		b_offset;	/* page offset in first page */
 	unsigned short		b_error;	/* error code on I/O */
 
+	void			(*b_pre_io)(struct xfs_buf *);
+						/* pre-io callback function */
+
 #ifdef XFS_BUF_LOCK_TRACKING
 	int			b_last_holder;
 #endif