1 files changed, 41 insertions, 13 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 108c7a085f94..be7cf625421f 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -887,7 +887,7 @@ xfs_iread(
          * around for a while.  This helps to keep recently accessed
          * meta-data in-core longer.
          */
-        XFS_BUF_SET_REF(bp, XFS_INO_REF);
+        xfs_buf_set_ref(bp, XFS_INO_REF);
 
         /*
          * Use xfs_trans_brelse() to release the buffer containing the
@@ -2000,17 +2000,33 @@ xfs_ifree_cluster(
                  */
                 for (i = 0; i < ninodes; i++) {
 retry:
-                        read_lock(&pag->pag_ici_lock);
+                        rcu_read_lock();
                         ip = radix_tree_lookup(&pag->pag_ici_root,
                                         XFS_INO_TO_AGINO(mp, (inum + i)));
 
-                        /* Inode not in memory or stale, nothing to do */
-                        if (!ip || xfs_iflags_test(ip, XFS_ISTALE)) {
-                                read_unlock(&pag->pag_ici_lock);
+                        /* Inode not in memory, nothing to do */
+                        if (!ip) {
+                                rcu_read_unlock();
                                 continue;
                         }
 
                         /*
+                         * because this is an RCU protected lookup, we could
+                         * find a recently freed or even reallocated inode
+                         * during the lookup. We need to check under the
+                         * i_flags_lock for a valid inode here. Skip it if it
+                         * is not valid, the wrong inode or stale.
+                         */
+                        spin_lock(&ip->i_flags_lock);
+                        if (ip->i_ino != inum + i ||
+                            __xfs_iflags_test(ip, XFS_ISTALE)) {
+                                spin_unlock(&ip->i_flags_lock);
+                                rcu_read_unlock();
+                                continue;
+                        }
+                        spin_unlock(&ip->i_flags_lock);
+
+                        /*
                          * Don't try to lock/unlock the current inode, but we
                          * _cannot_ skip the other inodes that we did not find
                          * in the list attached to the buffer and are not
@@ -2019,11 +2035,11 @@ retry:
                          */
                         if (ip != free_ip &&
                             !xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
-                                read_unlock(&pag->pag_ici_lock);
+                                rcu_read_unlock();
                                 delay(1);
                                 goto retry;
                         }
-                        read_unlock(&pag->pag_ici_lock);
+                        rcu_read_unlock();
 
                         xfs_iflock(ip);
                         xfs_iflags_set(ip, XFS_ISTALE);
@@ -2629,7 +2645,7 @@ xfs_iflush_cluster(
 
         mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
         first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
-        read_lock(&pag->pag_ici_lock);
+        rcu_read_lock();
         /* really need a gang lookup range call here */
         nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)ilist,
                                         first_index, inodes_per_cluster);
@@ -2640,9 +2656,21 @@ xfs_iflush_cluster(
                 iq = ilist[i];
                 if (iq == ip)
                         continue;
-                /* if the inode lies outside this cluster, we're done. */
-                if ((XFS_INO_TO_AGINO(mp, iq->i_ino) & mask) != first_index)
-                        break;
+
+                /*
+                 * because this is an RCU protected lookup, we could find a
+                 * recently freed or even reallocated inode during the lookup.
+                 * We need to check under the i_flags_lock for a valid inode
+                 * here. Skip it if it is not valid or the wrong inode.
+                 */
+                spin_lock(&ip->i_flags_lock);
+                if (!ip->i_ino ||
+                    (XFS_INO_TO_AGINO(mp, iq->i_ino) & mask) != first_index) {
+                        spin_unlock(&ip->i_flags_lock);
+                        continue;
+                }
+                spin_unlock(&ip->i_flags_lock);
+
                 /*
                  * Do an un-protected check to see if the inode is dirty and
                  * is a candidate for flushing.  These checks will be repeated
@@ -2692,7 +2720,7 @@ xfs_iflush_cluster(
         }
 
 out_free:
-        read_unlock(&pag->pag_ici_lock);
+        rcu_read_unlock();
         kmem_free(ilist);
 out_put:
         xfs_perag_put(pag);
@@ -2704,7 +2732,7 @@ cluster_corrupt_out:
          * Corruption detected in the clustering loop.  Invalidate the
          * inode buffer and shut down the filesystem.
          */
-        read_unlock(&pag->pag_ici_lock);
+        rcu_read_unlock();
         /*
          * Clean up the buffer.  If it was B_DELWRI, just release it --
          * brelse can handle it with no problems.  If not, shut down the