1 files changed, 20 insertions, 0 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 56d1614760cf..fbbb9eb92e32 100644
--- a/fs/xfs/xfs_buf.c
+++ b/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));
@@ -1487,6 +1505,8 @@ restart:
         while (!list_empty(&btp->bt_lru)) {
                 bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
                 if (atomic_read(&bp->b_hold) > 1) {
+                        trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
+                        list_move_tail(&bp->b_lru, &btp->bt_lru);
                         spin_unlock(&btp->bt_lru_lock);
                         delay(100);
                         goto restart;