Re: [PATCH 07/47] xfs: add function pointers for get/update keys to the btree

Brian Foster
2016-07-26T19:10:01Z

On Wed, Jul 20, 2016 at 09:56:46PM -0700, Darrick J. Wong wrote:
> Add some function pointers to bc_ops to get the btree keys for
> leaf and node blocks, and to update parent keys of a block.
> Convert the _btree_updkey calls to use our new pointer, and
> modify the tree shape changing code to call the appropriate
> get_*_keys pointer instead of _btree_copy_keys because the
> overlapping btree has to calculate high key values.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/libxfs/xfs_alloc_btree.c | 4 +
> fs/xfs/libxfs/xfs_bmap_btree.c | 4 +
> fs/xfs/libxfs/xfs_btree.c | 159 +++++++++++++++++++++++---------------
> fs/xfs/libxfs/xfs_btree.h | 19 +++++
> fs/xfs/libxfs/xfs_ialloc_btree.c | 8 ++
> 5 files changed, 133 insertions(+), 61 deletions(-)
>
>
...
> diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
> index 8d8e362..70d1c60 100644
> --- a/fs/xfs/libxfs/xfs_btree.c
> +++ b/fs/xfs/libxfs/xfs_btree.c
...
> @@ -2149,8 +2197,8 @@ xfs_btree_lshift(
> rkp = &key;
> }
>
> - /* Update the parent key values of right. */
> - error = xfs_btree_updkey(cur, rkp, level + 1);
> + /* Update the parent keys of the right block. */
> + error = cur->bc_ops->update_keys(cur, level);

Looks like there's some code to set up rkp just above that can probably
die.

> if (error)
> goto error0;
>
> @@ -2321,7 +2369,8 @@ xfs_btree_rshift(
> if (error)
> goto error1;
>
> - error = xfs_btree_updkey(tcur, rkp, level + 1);
> + /* Update the parent keys of the right block. */
> + error = cur->bc_ops->update_keys(tcur, level);

Similar deal here, just a bit further up.

> if (error)
> goto error1;
>
> @@ -2422,6 +2471,10 @@ __xfs_btree_split(
>
> XFS_BTREE_STATS_ADD(cur, moves, rrecs);
>
> + lrecs -= rrecs;
> + xfs_btree_set_numrecs(left, lrecs);
> + xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
> +
> /*
> * Copy btree block entries from the left block over to the
> * new block, the right. Update the right block and log the
> @@ -2447,14 +2500,15 @@ __xfs_btree_split(
> }
> #endif
>
> + /* Copy the keys & pointers to the new block. */
> xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
> xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
>
> xfs_btree_log_keys(cur, rbp, 1, rrecs);
> xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
>
> - /* Grab the keys to the entries moved to the right block */
> - xfs_btree_copy_keys(cur, key, rkp, 1);
> + /* Stash the keys of the new block for later insertion. */
> + cur->bc_ops->get_node_keys(cur, right, key);
> } else {
> /* It's a leaf. Move records. */
> union xfs_btree_rec *lrp; /* left record pointer */
> @@ -2463,14 +2517,14 @@ __xfs_btree_split(
> lrp = xfs_btree_rec_addr(cur, src_index, left);
> rrp = xfs_btree_rec_addr(cur, 1, right);
>
> + /* Copy records to the new block. */
> xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
> xfs_btree_log_recs(cur, rbp, 1, rrecs);
>
> - cur->bc_ops->init_key_from_rec(key,
> - xfs_btree_rec_addr(cur, 1, right));
> + /* Stash the keys of the new block for later insertion. */
> + cur->bc_ops->get_leaf_keys(cur, right, key);
> }
>
> -
> /*
> * Find the left block number by looking in the buffer.
> * Adjust numrecs, sibling pointers.
> @@ -2480,10 +2534,6 @@ __xfs_btree_split(
> xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
> xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
>
> - lrecs -= rrecs;
> - xfs_btree_set_numrecs(left, lrecs);
> - xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
> -

The immediately previous comment needs an update if this gets moved.

> xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
> xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
>
...
> diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
> index b4f3035..bb40457 100644
> --- a/fs/xfs/libxfs/xfs_btree.h
> +++ b/fs/xfs/libxfs/xfs_btree.h
> @@ -180,6 +180,19 @@ struct xfs_btree_ops {
> union xfs_btree_rec *r1,
> union xfs_btree_rec *r2);
> #endif
> +
> + /* derive the low & high keys from the records in a leaf block */
> + void (*get_leaf_keys)(struct xfs_btree_cur *cur,
> + struct xfs_btree_block *block,
> + union xfs_btree_key *key);
> +
> + /* derive the low & high keys from the keys in a node block */
> + void (*get_node_keys)(struct xfs_btree_cur *cur,
> + struct xfs_btree_block *block,
> + union xfs_btree_key *key);
> +
> + /* update the parent keys of given btree level */
> + int (*update_keys)(struct xfs_btree_cur *cur, int level);
> };
>
> /*
> @@ -474,5 +487,11 @@ bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
> bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
> uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
> unsigned long len);
> +

Whitespace damage here ^

Brian

> +void xfs_btree_get_leaf_keys(struct xfs_btree_cur *cur,
> + struct xfs_btree_block *block, union xfs_btree_key *key);
> +void xfs_btree_get_node_keys(struct xfs_btree_cur *cur,
> + struct xfs_btree_block *block, union xfs_btree_key *key);
> +int xfs_btree_update_keys(struct xfs_btree_cur *cur, int level);
>
> #endif /* __XFS_BTREE_H__ */
> diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
> index 88da2ad..a48f448 100644
> --- a/fs/xfs/libxfs/xfs_ialloc_btree.c
> +++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
> @@ -314,6 +314,10 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
> .keys_inorder = xfs_inobt_keys_inorder,
> .recs_inorder = xfs_inobt_recs_inorder,
> #endif
> +
> + .get_leaf_keys = xfs_btree_get_leaf_keys,
> + .get_node_keys = xfs_btree_get_node_keys,
> + .update_keys = xfs_btree_update_keys,
> };
>
> static const struct xfs_btree_ops xfs_finobt_ops = {
> @@ -335,6 +339,10 @@ static const struct xfs_btree_ops xfs_finobt_ops = {
> .keys_inorder = xfs_inobt_keys_inorder,
> .recs_inorder = xfs_inobt_recs_inorder,
> #endif
> +
> + .get_leaf_keys = xfs_btree_get_leaf_keys,
> + .get_node_keys = xfs_btree_get_node_keys,
> + .update_keys = xfs_btree_update_keys,
> };
>
> /*
>
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