[XFS] Don't grow filesystems past the size they can index.

When growing a filesystem we don't check to see if the new size overflows
the page cache index range, so we can do silly things like grow a
filesystem page 16TB on a 32bit. Check new filesystem sizes against the
limits the kernel can support.

SGI-PV: 957886
SGI-Modid: xfs-linux-melb:xfs-kern:28563a

Signed-Off-By: Nathan Scott <nscott@aconex.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index b3a5f07bd073..47082c01872d 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1882,11 +1882,13 @@ xfs_growfs_rt(
             (nrblocks = in->newblocks) <= sbp->sb_rblocks ||
             (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))
                 return XFS_ERROR(EINVAL);
+        if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))
+                return error;
         /*
          * Read in the last block of the device, make sure it exists.
          */
         error = xfs_read_buf(mp, mp->m_rtdev_targp,
-                        XFS_FSB_TO_BB(mp, in->newblocks - 1),
+                        XFS_FSB_TO_BB(mp, nrblocks - 1),
                         XFS_FSB_TO_BB(mp, 1), 0, &bp);
         if (error)
                 return error;