xfs: use the actual AG length when reserving blocks

commit 20e73b000bcded44a91b79429d8fa743247602ad upstream.

We need to use the actual AG length when making per-AG reservations,
since we could otherwise end up reserving more blocks out of the last
AG than there are actual blocks.

Complained-about-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 34 insertions, 12 deletions

diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
index e5ebc3770460..d346d42c54d1 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.c
+++ b/fs/xfs/libxfs/xfs_ag_resv.c
@@ -256,6 +256,9 @@ xfs_ag_resv_init(
                         goto out;
         }
 
+        ASSERT(xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved +
+               xfs_perag_resv(pag, XFS_AG_RESV_AGFL)->ar_reserved <=
+               pag->pagf_freeblks + pag->pagf_flcount);
 out:
         return error;
 }
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.c b/fs/xfs/libxfs/xfs_refcount_btree.c
index 453bb2757ec2..2ba216966002 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.c
+++ b/fs/xfs/libxfs/xfs_refcount_btree.c
@@ -408,13 +408,14 @@ xfs_refcountbt_calc_size(
  */
 xfs_extlen_t
 xfs_refcountbt_max_size(
-        struct xfs_mount        *mp)
+        struct xfs_mount        *mp,
+        xfs_agblock_t           agblocks)
 {
         /* Bail out if we're uninitialized, which can happen in mkfs. */
         if (mp->m_refc_mxr[0] == 0)
                 return 0;
 
-        return xfs_refcountbt_calc_size(mp, mp->m_sb.sb_agblocks);
+        return xfs_refcountbt_calc_size(mp, agblocks);
 }
 
 /*
@@ -429,22 +430,24 @@ xfs_refcountbt_calc_reserves(
 {
         struct xfs_buf          *agbp;
         struct xfs_agf          *agf;
+        xfs_agblock_t           agblocks;
         xfs_extlen_t            tree_len;
         int                     error;
 
         if (!xfs_sb_version_hasreflink(&mp->m_sb))
                 return 0;
 
-        *ask += xfs_refcountbt_max_size(mp);
 
         error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
         if (error)
                 return error;
 
         agf = XFS_BUF_TO_AGF(agbp);
+        agblocks = be32_to_cpu(agf->agf_length);
         tree_len = be32_to_cpu(agf->agf_refcount_blocks);
         xfs_buf_relse(agbp);
 
+        *ask += xfs_refcountbt_max_size(mp, agblocks);
         *used += tree_len;
 
         return error;
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.h b/fs/xfs/libxfs/xfs_refcount_btree.h
index 3be7768bd51a..9db008b955b7 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.h
+++ b/fs/xfs/libxfs/xfs_refcount_btree.h
@@ -66,7 +66,8 @@ extern void xfs_refcountbt_compute_maxlevels(struct xfs_mount *mp);
 
 extern xfs_extlen_t xfs_refcountbt_calc_size(struct xfs_mount *mp,
                 unsigned long long len);
-extern xfs_extlen_t xfs_refcountbt_max_size(struct xfs_mount *mp);
+extern xfs_extlen_t xfs_refcountbt_max_size(struct xfs_mount *mp,
+                xfs_agblock_t agblocks);
 
 extern int xfs_refcountbt_calc_reserves(struct xfs_mount *mp,
                 xfs_agnumber_t agno, xfs_extlen_t *ask, xfs_extlen_t *used);
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 83e672ff7577..33a28efc3085 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -549,13 +549,14 @@ xfs_rmapbt_calc_size(
  */
 xfs_extlen_t
 xfs_rmapbt_max_size(
-        struct xfs_mount        *mp)
+        struct xfs_mount        *mp,
+        xfs_agblock_t           agblocks)
 {
         /* Bail out if we're uninitialized, which can happen in mkfs. */
         if (mp->m_rmap_mxr[0] == 0)
                 return 0;
 
-        return xfs_rmapbt_calc_size(mp, mp->m_sb.sb_agblocks);
+        return xfs_rmapbt_calc_size(mp, agblocks);
 }
 
 /*
@@ -570,25 +571,24 @@ xfs_rmapbt_calc_reserves(
 {
         struct xfs_buf          *agbp;
         struct xfs_agf          *agf;
-        xfs_extlen_t            pool_len;
+        xfs_agblock_t           agblocks;
         xfs_extlen_t            tree_len;
         int                     error;
 
         if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
                 return 0;
 
-        /* Reserve 1% of the AG or enough for 1 block per record. */
-        pool_len = max(mp->m_sb.sb_agblocks / 100, xfs_rmapbt_max_size(mp));
-        *ask += pool_len;
-
         error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
         if (error)
                 return error;
 
         agf = XFS_BUF_TO_AGF(agbp);
+        agblocks = be32_to_cpu(agf->agf_length);
         tree_len = be32_to_cpu(agf->agf_rmap_blocks);
         xfs_buf_relse(agbp);
 
+        /* Reserve 1% of the AG or enough for 1 block per record. */
+        *ask += max(agblocks / 100, xfs_rmapbt_max_size(mp, agblocks));
         *used += tree_len;
 
         return error;
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.h b/fs/xfs/libxfs/xfs_rmap_btree.h
index 2a9ac472fb15..19c08e933049 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.h
+++ b/fs/xfs/libxfs/xfs_rmap_btree.h
@@ -60,7 +60,8 @@ extern void xfs_rmapbt_compute_maxlevels(struct xfs_mount *mp);
 
 extern xfs_extlen_t xfs_rmapbt_calc_size(struct xfs_mount *mp,
                 unsigned long long len);
-extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp);
+extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp,
+                xfs_agblock_t agblocks);
 
 extern int xfs_rmapbt_calc_reserves(struct xfs_mount *mp,
                 xfs_agnumber_t agno, xfs_extlen_t *ask, xfs_extlen_t *used);
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 93d12fa2670d..242e8091296d 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -631,6 +631,20 @@ xfs_growfs_data_private(
         xfs_set_low_space_thresholds(mp);
         mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
 
+        /*
+         * If we expanded the last AG, free the per-AG reservation
+         * so we can reinitialize it with the new size.
+         */
+        if (new) {
+                struct xfs_perag        *pag;
+
+                pag = xfs_perag_get(mp, agno);
+                error = xfs_ag_resv_free(pag);
+                xfs_perag_put(pag);
+                if (error)
+                        goto out;
+        }
+
         /* Reserve AG metadata blocks. */
         error = xfs_fs_reserve_ag_blocks(mp);
         if (error && error != -ENOSPC)