[PATCH 3/3] xfs: make growfs initialise the AGFL header

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

For verification purposes, AGFLs need to be initialised to a known
set of values. For upcoming CRC changes, the 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.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 fs/xfs/xfs_alloc.c |    2 +-
 fs/xfs/xfs_alloc.h |    1 +
 fs/xfs/xfs_fsops.c |   21 +++++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 8517e69..5b2357e 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -479,7 +479,7 @@ xfs_agfl_read_verify(
        xfs_agfl_verify(bp);
 }
 
-static const struct xfs_buf_ops xfs_agfl_buf_ops = {
+const struct xfs_buf_ops xfs_agfl_buf_ops = {
        .verify_read = xfs_agfl_read_verify,
        .verify_write = xfs_agfl_write_verify,
 };
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h
index 786e1b8..a197b3c 100644
--- a/fs/xfs/xfs_alloc.h
+++ b/fs/xfs/xfs_alloc.h
@@ -239,5 +239,6 @@ xfs_alloc_freespace_map(
        u64                     length);
 
 extern const struct xfs_buf_ops xfs_agf_buf_ops;
+extern const struct xfs_buf_ops xfs_agfl_buf_ops;
 
 #endif /* __XFS_ALLOC_H__ */
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 717b803..2f7d11e 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;
@@ -249,6 +250,26 @@ xfs_growfs_data_private(
                        goto error0;
 
                /*
+                * AGFL 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, &xfs_agfl_buf_ops);
+               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,
-- 
1.7.10