From 41e58880f6ba868339754e82414c9e413b9f254d Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@redhat.com>
Date: Mon, 21 Jan 2013 23:53:52 +1100
Subject: [PATCH] --- yaml --- r: 352922 b: refs/heads/master c:
 10616b806d1d7835b1d23b8d75ef638f92cb98b6 h: refs/heads/master v: v3

---
 [refs]                 |  2 +-
 trunk/fs/xfs/xfs_buf.c | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 1acb42a08c39..62583bd34152 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 003fd6c8be14a348c56cb1d171605ab13fca906f
+refs/heads/master: 10616b806d1d7835b1d23b8d75ef638f92cb98b6
diff --git a/trunk/fs/xfs/xfs_buf.c b/trunk/fs/xfs/xfs_buf.c
index 56d1614760cf..689d72655ea6 100644
--- a/trunk/fs/xfs/xfs_buf.c
+++ b/trunk/fs/xfs/xfs_buf.c
@@ -487,6 +487,7 @@ _xfs_buf_find(
 	struct rb_node		*parent;
 	xfs_buf_t		*bp;
 	xfs_daddr_t		blkno = map[0].bm_bn;
+	xfs_daddr_t		eofs;
 	int			numblks = 0;
 	int			i;
 
@@ -498,6 +499,23 @@ _xfs_buf_find(
 	ASSERT(!(numbytes < (1 << btp->bt_sshift)));
 	ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask));
 
+	/*
+	 * Corrupted block numbers can get through to here, unfortunately, so we
+	 * have to check that the buffer falls within the filesystem bounds.
+	 */
+	eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks);
+	if (blkno >= eofs) {
+		/*
+		 * XXX (dgc): we should really be returning EFSCORRUPTED here,
+		 * but none of the higher level infrastructure supports
+		 * returning a specific error on buffer lookup failures.
+		 */
+		xfs_alert(btp->bt_mount,
+			  "%s: Block out of range: block 0x%llx, EOFS 0x%llx ",
+			  __func__, blkno, eofs);
+		return NULL;
+	}
+
 	/* get tree root */
 	pag = xfs_perag_get(btp->bt_mount,
 				xfs_daddr_to_agno(btp->bt_mount, blkno));