xfs: make growfs initialise the AGFL header

For verification purposes, AGFLs need to be initialised to a known
set of values. For upcoming CRC changes, they are also headers that
need to be initialised. Currently, growfs does neither for the AGFLs
- it ignores them completely. Add initialisation of the AGFL to be
full of invalid block numbers (NULLAGBLOCK) to put the
infrastructure in place needed for CRC support.

Includes a comment clarification from Jeff Liu.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 2196830bf5c0..bd9cb7f0b073 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -140,6 +140,7 @@ xfs_growfs_data_private(
         xfs_growfs_data_t       *in)            /* growfs data input struct */
 {
         xfs_agf_t               *agf;
+        struct xfs_agfl         *agfl;
         xfs_agi_t               *agi;
         xfs_agnumber_t          agno;
         xfs_extlen_t            agsize;
@@ -207,7 +208,7 @@ xfs_growfs_data_private(
         nfree = 0;
         for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
                 /*
-                 * AG freelist header block
+                 * AG freespace header block
                  */
                 bp = xfs_growfs_get_hdr_buf(mp,
                                 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
@@ -244,6 +245,26 @@ xfs_growfs_data_private(
                         goto error0;
 
                 /*
+                 * AG freelist header block
+                 */
+                bp = xfs_growfs_get_hdr_buf(mp,
+                                XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
+                                XFS_FSS_TO_BB(mp, 1), 0);
+                if (!bp) {
+                        error = ENOMEM;
+                        goto error0;
+                }
+
+                agfl = XFS_BUF_TO_AGFL(bp);
+                for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
+                        agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
+
+                error = xfs_bwrite(bp);
+                xfs_buf_relse(bp);
+                if (error)
+                        goto error0;
+
+                /*
                  * AG inode header block
                  */
                 bp = xfs_growfs_get_hdr_buf(mp,