xfs: use unhashed buffers for size checks

When we are checking we can access the last block of each device, we
do not need to use cached buffers as they will be tossed away
immediately. Use uncached buffers for size checks so that all IO
prior to full in-memory structure initialisation does not use the
buffer cache.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

1 files changed, 5 insertions, 6 deletions

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 43b1d5699335..6a1edb1348f6 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -144,12 +144,11 @@ xfs_growfs_data_private(
         if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
                 return error;
         dpct = pct - mp->m_sb.sb_imax_pct;
-        error = xfs_read_buf(mp, mp->m_ddev_targp,
-                        XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
-                        XFS_FSS_TO_BB(mp, 1), 0, &bp);
-        if (error)
-                return error;
-        ASSERT(bp);
+        bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+                                XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
+                                BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
+        if (!bp)
+                return EIO;
         xfs_buf_relse(bp);
 
         new = nb;       /* use new as a temporary here */