xfs: encode the max btree height in the cursor

Encode the maximum btree height in the cursor, since we're soon going to
allow smaller cursors for AG btrees and larger cursors for file btrees.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 644b956..2ae5bf9 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -239,7 +239,7 @@ xfs_bmap_get_bp(
        if (!cur)
                return NULL;
 
-       for (i = 0; i < XFS_BTREE_MAXLEVELS; i++) {
+       for (i = 0; i < cur->bc_maxlevels; i++) {
                if (!cur->bc_levels[i].bp)
                        break;
                if (xfs_buf_daddr(cur->bc_levels[i].bp) == bno)

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 25dfab8..6ced8f0 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -2933,7 +2933,7 @@ xfs_btree_new_iroot(
        be16_add_cpu(&block->bb_level, 1);
        xfs_btree_set_numrecs(block, 1);
        cur->bc_nlevels++;
-       ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);
+       ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
        cur->bc_levels[level + 1].ptr = 1;
 
        kp = xfs_btree_key_addr(cur, 1, block);
@@ -3097,7 +3097,7 @@ xfs_btree_new_root(
        xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
        cur->bc_levels[cur->bc_nlevels].ptr = nptr;
        cur->bc_nlevels++;
-       ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);
+       ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
        *stat = 1;
        return 0;
 error0:

diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 8e78ede..ed0b7d5 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -238,6 +238,7 @@ struct xfs_btree_cur
        xfs_btnum_t             bc_btnum; /* identifies which btree type */
        union xfs_btree_irec    bc_rec; /* current insert/search record value */
        uint8_t                 bc_nlevels; /* number of levels in the tree */
+       uint8_t                 bc_maxlevels; /* maximum levels for this btree type */
        int                     bc_statoff; /* offset of btree stats array */
 
        /*
@@ -590,6 +591,7 @@ xfs_btree_alloc_cursor(
        cur->bc_tp = tp;
        cur->bc_mp = mp;
        cur->bc_btnum = btnum;
+       cur->bc_maxlevels = XFS_BTREE_MAXLEVELS;
 
        return cur;
 }

diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c
index cc56efc..dd75e20 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree_staging.c
+++ b/fs/xfs/libxfs/xfs_btree_staging.c
@@ -657,12 +657,12 @@ xfs_btree_bload_compute_geometry(
         * checking levels 0 and 1 here, so set bc_nlevels such that the btree
         * code doesn't interpret either as the root level.
         */
-       cur->bc_nlevels = XFS_BTREE_MAXLEVELS - 1;
+       cur->bc_nlevels = cur->bc_maxlevels - 1;
        xfs_btree_bload_ensure_slack(cur, &bbl->leaf_slack, 0);
        xfs_btree_bload_ensure_slack(cur, &bbl->node_slack, 1);
 
        bbl->nr_records = nr_this_level = nr_records;
-       for (cur->bc_nlevels = 1; cur->bc_nlevels <= XFS_BTREE_MAXLEVELS;) {
+       for (cur->bc_nlevels = 1; cur->bc_nlevels <= cur->bc_maxlevels;) {
                uint64_t        level_blocks;
                uint64_t        dontcare64;
                unsigned int    level = cur->bc_nlevels - 1;
@@ -703,7 +703,7 @@ xfs_btree_bload_compute_geometry(
                         * block-based btree level.
                         */
                        cur->bc_nlevels++;
-                       ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);
+                       ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
                        xfs_btree_bload_level_geometry(cur, bbl, level,
                                        nr_this_level, &avg_per_block,
                                        &level_blocks, &dontcare64);
@@ -719,14 +719,14 @@ xfs_btree_bload_compute_geometry(
 
                        /* Otherwise, we need another level of btree. */
                        cur->bc_nlevels++;
-                       ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);
+                       ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
                }
 
                nr_blocks += level_blocks;
                nr_this_level = level_blocks;
        }
 
-       if (cur->bc_nlevels > XFS_BTREE_MAXLEVELS)
+       if (cur->bc_nlevels > cur->bc_maxlevels)
                return -EOVERFLOW;
 
        bbl->btree_height = cur->bc_nlevels;