[PATCH 10/14] xfs: encode the max btree height in the cursor

Darrick J. Wong
2021-09-18T01:30:07Z

From: Darrick J. Wong <djwong@kernel.org>

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>
---
fs/xfs/libxfs/xfs_bmap.c | 2 +-
fs/xfs/libxfs/xfs_btree.c | 5 +++--
fs/xfs/libxfs/xfs_btree.h | 3 ++-
fs/xfs/libxfs/xfs_btree_staging.c | 10 +++++-----
4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 644b956301b6..2ae5bf9a74e7 100644
--- 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 70785004414e..2486ba22c01d 100644
--- 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:
@@ -4941,6 +4941,7 @@ xfs_btree_alloc_cursor(
cur->bc_mp = mp;
cur->bc_btnum = btnum;
cur->bc_blocklog = mp->m_sb.sb_blocklog;
+ cur->bc_maxlevels = XFS_BTREE_MAXLEVELS;

return cur;
}
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 6540c4957c36..6075918efa0c 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -235,9 +235,10 @@ struct xfs_btree_cur
struct xfs_mount *bc_mp; /* file system mount struct */
const struct xfs_btree_ops *bc_ops;
uint bc_flags; /* btree features - below */
- union xfs_btree_irec bc_rec; /* current insert/search record value */
+ uint8_t bc_maxlevels; /* maximum levels for this btree type */
uint8_t bc_nlevels; /* number of levels in the tree */
uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
+ union xfs_btree_irec bc_rec; /* current insert/search record value */
xfs_btnum_t bc_btnum; /* identifies which btree type */
int bc_statoff; /* offset of btre stats array */

diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c
index cc56efc2b90a..dd75e208b543 100644
--- 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;