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

Darrick J. Wong
2016-07-28T19:14:00Z

On Tue, Jul 26, 2016 at 03:09:54PM -0400, Brian Foster wrote:
> 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.

Yup, both rkp = &key instances can go.

> > 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.

I'll update the comment and add a new one at the new site explaining why the
numrecs update has to come first (the overlapped get_keys() functions need it).

> > 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 ^

Oops. Will fix, thanks for the review!

--D

>
> 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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> > xfs@oss.sgi.com
> > http://oss.sgi.com/mailman/listinfo/xfs