1 files changed, 36 insertions, 8 deletions

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index afe4d29f7ab4..ac0fcdad0c4e 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -861,6 +861,21 @@ out_trans_cancel:
         return error;
 }
 
+static void
+xfs_alloc_rsum_cache(
+        xfs_mount_t     *mp,            /* file system mount structure */
+        xfs_extlen_t    rbmblocks)      /* number of rt bitmap blocks */
+{
+        /*
+         * The rsum cache is initialized to all zeroes, which is trivially a
+         * lower bound on the minimum level with any free extents. We can
+         * continue without the cache if it couldn't be allocated.
+         */
+        mp->m_rsum_cache = kmem_zalloc_large(rbmblocks, KM_SLEEP);
+        if (!mp->m_rsum_cache)
+                xfs_warn(mp, "could not allocate realtime summary cache");
+}
+
 /*
  * Visible (exported) functions.
  */
@@ -889,6 +904,7 @@ xfs_growfs_rt(
         xfs_extlen_t    rsumblocks;     /* current number of rt summary blks */
         xfs_sb_t        *sbp;           /* old superblock */
         xfs_fsblock_t   sumbno;         /* summary block number */
+        uint8_t         *rsum_cache;    /* old summary cache */
 
         sbp = &mp->m_sb;
         /*
@@ -945,6 +961,11 @@ xfs_growfs_rt(
         error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
         if (error)
                 return error;
+
+        rsum_cache = mp->m_rsum_cache;
+        if (nrbmblocks != sbp->sb_rbmblocks)
+                xfs_alloc_rsum_cache(mp, nrbmblocks);
+
         /*
          * Allocate a new (fake) mount/sb.
          */
@@ -1070,6 +1091,20 @@ error_cancel:
          */
         kmem_free(nmp);
 
+        /*
+         * If we had to allocate a new rsum_cache, we either need to free the
+         * old one (if we succeeded) or free the new one and restore the old one
+         * (if there was an error).
+         */
+        if (rsum_cache != mp->m_rsum_cache) {
+                if (error) {
+                        kmem_free(mp->m_rsum_cache);
+                        mp->m_rsum_cache = rsum_cache;
+                } else {
+                        kmem_free(rsum_cache);
+                }
+        }
+
         return error;
 }
 
@@ -1217,14 +1252,7 @@ xfs_rtmount_inodes(
                 return error;
         }
         ASSERT(mp->m_rsumip != NULL);
-        /*
-         * The rsum cache is initialized to all zeroes, which is trivially a
-         * lower bound on the minimum level with any free extents. We can
-         * continue without the cache if it couldn't be allocated.
-         */
-        mp->m_rsum_cache = kmem_zalloc_large(sbp->sb_rbmblocks, KM_SLEEP);
-        if (!mp->m_rsum_cache)
-                xfs_warn(mp, "could not allocate realtime summary cache");
+        xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
         return 0;
 }