[XFS] Extra check on the mount path - ensure we don't attempt to mount XFS fs's

with sector sizes smaller than those the device supports.  Tripped a BUG
in pagebuf, should now be resolved.

SGI Modid: 2.5.x-xfs:slinx:139328a

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index df578881cbcb248bccad08910902b9018b29457a..6fa2f67a7416cf205c958b12420d2eba4b9dd282 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -272,7 +272,7 @@ xfs_mount_validate_sb(
                cmn_err(CE_WARN,
                "XFS: Only page-sized (%d) or less blocksizes currently work.",
                        PAGE_SIZE);
-               return XFS_ERROR(EWRONGFS);
+               return XFS_ERROR(ENOSYS);
        }
 
        return 0;
@@ -459,10 +459,22 @@ xfs_readsb(xfs_mount_t *mp)
        }
 
        /*
-        * Re-read the superblock so that our buffer is correctly sized.
-        * We only need to do this if sector size on-disk is different.
+        * We must be able to do sector-sized and sector-aligned IO.
+        */
+       if (sector_size > mp->m_sb.sb_sectsize) {
+               cmn_err(CE_WARN,
+                       "XFS: device supports only %u byte sectors (not %u)",
+                       sector_size, mp->m_sb.sb_sectsize);
+               XFS_BUF_UNMANAGE(bp);
+               xfs_buf_relse(bp);
+               return XFS_ERROR(ENOSYS);
+       }
+
+       /*
+        * If device sector size is smaller than the superblock size,
+        * re-read the superblock so the buffer is correctly sized.
         */
-       if (sector_size != mp->m_sb.sb_sectsize) {
+       if (sector_size < mp->m_sb.sb_sectsize) {
                XFS_BUF_UNMANAGE(bp);
                xfs_buf_relse(bp);
                sector_size = mp->m_sb.sb_sectsize;