From: Darrick J. Wong <djwong@xxxxxxxxxx>
In preparation for allowing records in an inode btree root, hoist the
code that copies keyptrs from an existing node child into the root block
to a separate function. Remove some unnecessary conditionals and clean
up a few function calls in the new function. Note that this change
reorders the ->free_block call with respect to the change in bc_nlevels
to make it easier to support inode root leaf blocks in the next patch.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
libxfs/xfs_btree.c | 94 +++++++++++++++++++++++++++++++++-------------------
1 file changed, 60 insertions(+), 34 deletions(-)
diff --git a/libxfs/xfs_btree.c b/libxfs/xfs_btree.c
index 5a21788c707..0f0198ae0cd 100644
--- a/libxfs/xfs_btree.c
+++ b/libxfs/xfs_btree.c
@@ -3704,6 +3704,63 @@ xfs_btree_insert(
return error;
}
+/*
+ * Move the keyptrs from a child node block to the root block.
+ *
+ * Since the keyptr size does not change, all we have to do is increase the
+ * tree height, copy the keyptrs to the new internal node (cblock), shrink
+ * the root, and copy the pointers there.
+ */
+STATIC int
+xfs_btree_demote_node_child(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *cblock,
+ int level,
+ int numrecs)
+{
+ struct xfs_btree_block *block;
+ union xfs_btree_key *ckp;
+ union xfs_btree_key *kp;
+ union xfs_btree_ptr *cpp;
+ union xfs_btree_ptr *pp;
+ int i;
+ int error;
+ int diff;
+
+ /*
+ * Adjust the root btree node size and the record count to match the
+ * doomed child so that we can copy the keyptrs ahead of changing the
+ * tree shape.
+ */
+ diff = numrecs - cur->bc_ops->get_maxrecs(cur, level);
+ xfs_btree_iroot_realloc(cur, diff);
+ block = xfs_btree_get_iroot(cur);
+
+ xfs_btree_set_numrecs(block, numrecs);
+ ASSERT(block->bb_numrecs == cblock->bb_numrecs);
+
+ /* Copy keys from the doomed block. */
+ kp = xfs_btree_key_addr(cur, 1, block);
+ ckp = xfs_btree_key_addr(cur, 1, cblock);
+ xfs_btree_copy_keys(cur, kp, ckp, numrecs);
+
+ /* Copy pointers from the doomed block. */
+ pp = xfs_btree_ptr_addr(cur, 1, block);
+ cpp = xfs_btree_ptr_addr(cur, 1, cblock);
+ for (i = 0; i < numrecs; i++) {
+ error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
+ if (error)
+ return error;
+ }
+ xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
+
+ /* Decrease tree height, adjusting the root block level to match. */
+ cur->bc_levels[level - 1].bp = NULL;
+ be16_add_cpu(&block->bb_level, -1);
+ cur->bc_nlevels--;
+ return 0;
+}
+
/*
* Try to merge a non-leaf block back into the inode root.
*
@@ -3716,24 +3773,16 @@ STATIC int
xfs_btree_kill_iroot(
struct xfs_btree_cur *cur)
{
- int whichfork = cur->bc_ino.whichfork;
struct xfs_inode *ip = cur->bc_ino.ip;
- struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
struct xfs_btree_block *block;
struct xfs_btree_block *cblock;
- union xfs_btree_key *kp;
- union xfs_btree_key *ckp;
- union xfs_btree_ptr *pp;
- union xfs_btree_ptr *cpp;
struct xfs_buf *cbp;
int level;
- int index;
int numrecs;
int error;
#ifdef DEBUG
union xfs_btree_ptr ptr;
#endif
- int i;
ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
ASSERT(cur->bc_nlevels > 1);
@@ -3773,39 +3822,16 @@ xfs_btree_kill_iroot(
ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
#endif
- index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
- if (index) {
- xfs_btree_iroot_realloc(cur, index);
- block = ifp->if_broot;
- }
-
- be16_add_cpu(&block->bb_numrecs, index);
- ASSERT(block->bb_numrecs == cblock->bb_numrecs);
-
- kp = xfs_btree_key_addr(cur, 1, block);
- ckp = xfs_btree_key_addr(cur, 1, cblock);
- xfs_btree_copy_keys(cur, kp, ckp, numrecs);
-
- pp = xfs_btree_ptr_addr(cur, 1, block);
- cpp = xfs_btree_ptr_addr(cur, 1, cblock);
-
- for (i = 0; i < numrecs; i++) {
- error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
- if (error)
- return error;
- }
-
- xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
+ error = xfs_btree_demote_node_child(cur, cblock, level, numrecs);
+ if (error)
+ return error;
error = xfs_btree_free_block(cur, cbp);
if (error)
return error;
- cur->bc_levels[level - 1].bp = NULL;
- be16_add_cpu(&block->bb_level, -1);
xfs_trans_log_inode(cur->bc_tp, ip,
XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork));
- cur->bc_nlevels--;
out0:
return 0;
}
