Re: [PATCH v2 07/47] xfs: add function pointers for get/update keys to the btree

Brian Foster
2016-08-01T15:57:44Z

On Thu, Jul 28, 2016 at 12:46:15PM -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 | 164 +++++++++++++++++++++++---------------
> fs/xfs/libxfs/xfs_btree.h | 19 ++++
> fs/xfs/libxfs/xfs_ialloc_btree.c | 8 ++
> 5 files changed, 135 insertions(+), 64 deletions(-)
>
...
> diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
> index 8d8e362..405442d 100644
> --- a/fs/xfs/libxfs/xfs_btree.c
> +++ b/fs/xfs/libxfs/xfs_btree.c
...
> @@ -2146,11 +2194,10 @@ xfs_btree_lshift(
> */
> cur->bc_ops->init_key_from_rec(&key,
> xfs_btree_rec_addr(cur, 1, right));
> - rkp = &key;

Sorry, I should have been more clear. I think this entire hunk (the
above key initialization and comment) is effectively dead.

> }
>
> - /* 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);
> if (error)
> goto error0;
>
> @@ -2292,7 +2339,6 @@ xfs_btree_rshift(
> xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
>
> cur->bc_ops->init_key_from_rec(&key, rrp);
> - rkp = &key;

Same here. key isn't used beyond this.

I see that hch has some objections to the design here. FWIW, resolution
of that aside, and with the above fixes:

Reviewed-by: Brian Foster <bfoster@redhat.com>

>
> ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
> xfs_btree_rec_addr(cur, 2, right)));
> @@ -2321,7 +2367,8 @@ 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);
> if (error)
> goto error1;
>
> @@ -2422,6 +2469,11 @@ __xfs_btree_split(
>
> XFS_BTREE_STATS_ADD(cur, moves, rrecs);
>
> + /* Adjust numrecs for the later get_*_keys() calls. */
> + 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 +2499,15 @@ __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 */
> @@ -2463,27 +2516,23 @@ __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.
> + * Adjust sibling pointers.
> */
> xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
> xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
> 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);
> -
> xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
> xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
>
> @@ -2802,6 +2851,7 @@ xfs_btree_new_root(
> bp = lbp;
> nptr = 2;
> }
> +
> /* Fill in the new block's btree header and log it. */
> xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
> xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
> @@ -2810,19 +2860,24 @@ xfs_btree_new_root(
>
> /* Fill in the key data in the new root. */
> if (xfs_btree_get_level(left) > 0) {
> - xfs_btree_copy_keys(cur,
> - xfs_btree_key_addr(cur, 1, new),
> - xfs_btree_key_addr(cur, 1, left), 1);
> - xfs_btree_copy_keys(cur,
> - xfs_btree_key_addr(cur, 2, new),
> - xfs_btree_key_addr(cur, 1, right), 1);
> + /*
> + * Get the keys for the left block's keys and put them directly
> + * in the parent block. Do the same for the right block.
> + */
> + cur->bc_ops->get_node_keys(cur, left,
> + xfs_btree_key_addr(cur, 1, new));
> + cur->bc_ops->get_node_keys(cur, right,
> + xfs_btree_key_addr(cur, 2, new));
> } else {
> - cur->bc_ops->init_key_from_rec(
> - xfs_btree_key_addr(cur, 1, new),
> - xfs_btree_rec_addr(cur, 1, left));
> - cur->bc_ops->init_key_from_rec(
> - xfs_btree_key_addr(cur, 2, new),
> - xfs_btree_rec_addr(cur, 1, right));
> + /*
> + * Get the keys for the left block's records and put them
> + * directly in the parent block. Do the same for the right
> + * block.
> + */
> + cur->bc_ops->get_leaf_keys(cur, left,
> + xfs_btree_key_addr(cur, 1, new));
> + cur->bc_ops->get_leaf_keys(cur, right,
> + xfs_btree_key_addr(cur, 2, new));
> }
> xfs_btree_log_keys(cur, nbp, 1, 2);
>
> @@ -2858,7 +2913,7 @@ xfs_btree_make_block_unfull(
> int *index, /* new tree index */
> union xfs_btree_ptr *nptr, /* new btree ptr */
> struct xfs_btree_cur **ncur, /* new btree cursor */
> - union xfs_btree_key *key, /* key of new block */
> + union xfs_btree_key *key, /* key of new block */
> int *stat)
> {
> int error = 0;
> @@ -3086,8 +3141,8 @@ xfs_btree_insrec(
> xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
>
> /* If we inserted at the start of a block, update the parents' keys. */
> - if (optr == 1) {
> - error = xfs_btree_updkey(cur, key, level + 1);
> + if (xfs_btree_needs_key_update(cur, optr)) {
> + error = cur->bc_ops->update_keys(cur, level);
> if (error)
> goto error0;
> }
> @@ -3107,7 +3162,7 @@ xfs_btree_insrec(
> */
> *ptrp = nptr;
> if (!xfs_btree_ptr_is_null(cur, &nptr)) {
> - *key = nkey;
> + xfs_btree_copy_keys(cur, key, &nkey, 1);
> *curp = ncur;
> }
>
> @@ -3386,8 +3441,6 @@ xfs_btree_delrec(
> struct xfs_buf *bp; /* buffer for block */
> int error; /* error return value */
> int i; /* loop counter */
> - union xfs_btree_key key; /* storage for keyp */
> - union xfs_btree_key *keyp = &key; /* passed to the next level */
> union xfs_btree_ptr lptr; /* left sibling block ptr */
> struct xfs_buf *lbp; /* left buffer pointer */
> struct xfs_btree_block *left; /* left btree block */
> @@ -3458,13 +3511,6 @@ xfs_btree_delrec(
> xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
> xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
> }
> -
> - /*
> - * If it's the first record in the block, we'll need to pass a
> - * key up to the next level (updkey).
> - */
> - if (ptr == 1)
> - keyp = xfs_btree_key_addr(cur, 1, block);
> } else {
> /* It's a leaf. operate on records */
> if (ptr < numrecs) {
> @@ -3473,16 +3519,6 @@ xfs_btree_delrec(
> -1, numrecs - ptr);
> xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
> }
> -
> - /*
> - * If it's the first record in the block, we'll need a key
> - * structure to pass up to the next level (updkey).
> - */
> - if (ptr == 1) {
> - cur->bc_ops->init_key_from_rec(&key,
> - xfs_btree_rec_addr(cur, 1, block));
> - keyp = &key;
> - }
> }
>
> /*
> @@ -3549,8 +3585,8 @@ xfs_btree_delrec(
> * If we deleted the leftmost entry in the block, update the
> * key values above us in the tree.
> */
> - if (ptr == 1) {
> - error = xfs_btree_updkey(cur, keyp, level + 1);
> + if (xfs_btree_needs_key_update(cur, ptr)) {
> + error = cur->bc_ops->update_keys(cur, level);
> if (error)
> goto error0;
> }
> diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
> index b4f3035..e097e60 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);
> };
>
> /*
> @@ -475,4 +488,10 @@ 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);
>
> +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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