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

Christoph Hellwig
2016-08-02T12:23:38Z

On Mon, Aug 01, 2016 at 10:33:31AM -0700, Darrick J. Wong wrote:
> That's roughly the approach I took in previous versions of this patch,
> but using the OVERLAPPING flag to dispatch the overlapped vs. non-
> versions of the get*keys and updkey* functions confused Dave, so he
> asked me to add to function pointers[1] to the btree ops and dispatch
> that way.

I remember I had a similar disagreement with Dave on the long vs
short pointers when doing the initial common btree work, and
I prevailed using the flag :)

Below is a patch to on top of your for-dave-for-4.8-2 branch
which uses the flag, but also keeps your useful refactoring.

This both reduces source:

6 files changed, 61 insertions(+), 136 deletions(-)

as well as binary:

hch@brick:~/work/xfs$ size xfs.o-*
text data bss dec hex filename
911881 160951 1568 1074400 1064e0 xfs.o-flag
912457 160951 1568 1074976 106720 xfs.o-pointer

sizes and makes the whole thing much easier to follow and understand.

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index c60eeb8..5ba2dac 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -403,10 +403,6 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
.keys_inorder = xfs_allocbt_keys_inorder,
.recs_inorder = xfs_allocbt_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,
};

/*
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 9e34ca4..cd85274 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -763,10 +763,6 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
.keys_inorder = xfs_bmbt_keys_inorder,
.recs_inorder = xfs_bmbt_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,
};

/*
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index fe5f27e..45a9545b 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1951,29 +1951,6 @@ error0:
return error;
}

-/* Determine the low key of a leaf block (simple) */
-void
-xfs_btree_get_leaf_keys(
- struct xfs_btree_cur *cur,
- struct xfs_btree_block *block,
- union xfs_btree_key *key)
-{
- union xfs_btree_rec *rec;
-
- rec = xfs_btree_rec_addr(cur, 1, block);
- cur->bc_ops->init_key_from_rec(key, rec);
-}
-
-/* Determine the low key of a node block (simple) */
-void
-xfs_btree_get_node_keys(
- struct xfs_btree_cur *cur,
- struct xfs_btree_block *block,
- union xfs_btree_key *key)
-{
- memcpy(key, xfs_btree_key_addr(cur, 1, block), cur->bc_ops->key_len);
-}
-
/* Find the high key storage area from a regular key. */
STATIC union xfs_btree_key *
xfs_btree_high_key_from_key(
@@ -1985,38 +1962,41 @@ xfs_btree_high_key_from_key(
(cur->bc_ops->key_len / 2));
}

-/* Determine the low and high keys of a leaf block (overlapped) */
-void
-xfs_btree_get_leaf_keys_overlapped(
+/* Determine the low (and high if overlapped) key of a leaf block */
+STATIC void
+xfs_btree_get_leaf_keys(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_key *key)
{
- int n;
union xfs_btree_rec *rec;
- union xfs_btree_key max_hkey;
- union xfs_btree_key hkey;
- union xfs_btree_key *high;

- ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
rec = xfs_btree_rec_addr(cur, 1, block);
cur->bc_ops->init_key_from_rec(key, rec);

- cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
- for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
- rec = xfs_btree_rec_addr(cur, n, block);
- cur->bc_ops->init_high_key_from_rec(&hkey, rec);
- if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey) > 0)
- max_hkey = hkey;
- }
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ union xfs_btree_key max_hkey;
+ union xfs_btree_key hkey;
+ union xfs_btree_key *high;
+ int n;
+
+ cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
+ for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+ rec = xfs_btree_rec_addr(cur, n, block);
+ cur->bc_ops->init_high_key_from_rec(&hkey, rec);
+ if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
+ > 0)
+ max_hkey = hkey;
+ }

- high = xfs_btree_high_key_from_key(cur, key);
- memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
+ high = xfs_btree_high_key_from_key(cur, key);
+ memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
+ }
}

/* Determine the low and high keys of a node block (overlapped) */
-void
-xfs_btree_get_node_keys_overlapped(
+STATIC void
+xfs_btree_get_node_keys(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_key *key)
@@ -2026,19 +2006,23 @@ xfs_btree_get_node_keys_overlapped(
union xfs_btree_key *max_hkey;
union xfs_btree_key *high;

- ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
- memcpy(key, xfs_btree_key_addr(cur, 1, block),
- cur->bc_ops->key_len / 2);
-
- max_hkey = xfs_btree_high_key_addr(cur, 1, block);
- for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
- hkey = xfs_btree_high_key_addr(cur, n, block);
- if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
- max_hkey = hkey;
- }
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ memcpy(key, xfs_btree_key_addr(cur, 1, block),
+ cur->bc_ops->key_len / 2);
+
+ max_hkey = xfs_btree_high_key_addr(cur, 1, block);
+ for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+ hkey = xfs_btree_high_key_addr(cur, n, block);
+ if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
+ max_hkey = hkey;
+ }

- high = xfs_btree_high_key_from_key(cur, key);
- memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
+ high = xfs_btree_high_key_from_key(cur, key);
+ memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
+ } else {
+ memcpy(key, xfs_btree_key_addr(cur, 1, block),
+ cur->bc_ops->key_len);
+ }
}

/* Derive the keys for any btree block. */
@@ -2049,9 +2033,9 @@ xfs_btree_get_keys(
union xfs_btree_key *key)
{
if (be16_to_cpu(block->bb_level) == 0)
- cur->bc_ops->get_leaf_keys(cur, block, key);
+ xfs_btree_get_leaf_keys(cur, block, key);
else
- cur->bc_ops->get_node_keys(cur, block, key);
+ xfs_btree_get_node_keys(cur, block, key);
}

/*
@@ -2125,28 +2109,12 @@ __xfs_btree_updkeys(
xfs_btree_log_keys(cur, bp, ptr, ptr);
if (level + 1 >= cur->bc_nlevels)
break;
- cur->bc_ops->get_node_keys(cur, block, lkey);
+ xfs_btree_get_node_keys(cur, block, lkey);
}

return 0;
}

-/*
- * Update all the keys from some level in cursor back to the root, stopping
- * when we find a key pair that don't need updating.
- */
-int
-xfs_btree_update_keys_overlapped(
- struct xfs_btree_cur *cur,
- int level)
-{
- struct xfs_buf *bp;
- struct xfs_btree_block *block;
-
- block = xfs_btree_get_block(cur, level, &bp);
- return __xfs_btree_updkeys(cur, level, block, bp, false);
-}
-
/* Update all the keys from some level in cursor back to the root. */
STATIC int
xfs_btree_updkeys_force(
@@ -2163,7 +2131,7 @@ xfs_btree_updkeys_force(
/*
* Update the parent keys of the given level, progressing towards the root.
*/
-int
+STATIC int
xfs_btree_update_keys(
struct xfs_btree_cur *cur,
int level)
@@ -2174,20 +2142,21 @@ xfs_btree_update_keys(
union xfs_btree_key key;
int ptr;

- ASSERT(!(cur->bc_flags & XFS_BTREE_OVERLAPPING));
+ ASSERT(level >= 0);
+
+ block = xfs_btree_get_block(cur, level, &bp);
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
+ return __xfs_btree_updkeys(cur, level, block, bp, false);

XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGIK(cur, level, keyp);

- ASSERT(level >= 0);
-
/*
* Go up the tree from this level toward the root.
* At each level, update the key value to the value input.
* Stop when we reach a level where the cursor isn't pointing
* at the first entry in the block.
*/
- block = xfs_btree_get_block(cur, level, &bp);
xfs_btree_get_keys(cur, block, &key);
for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
#ifdef DEBUG
@@ -2257,7 +2226,7 @@ xfs_btree_update(

/* Pass new key value up to our parent. */
if (xfs_btree_needs_key_update(cur, ptr)) {
- error = cur->bc_ops->update_keys(cur, 0);
+ error = xfs_btree_update_keys(cur, 0);
if (error)
goto error0;
}
@@ -2447,13 +2416,13 @@ xfs_btree_lshift(
goto error1;

/* Update the parent keys of the right block. */
- error = cur->bc_ops->update_keys(cur, level);
+ error = xfs_btree_update_keys(cur, level);
if (error)
goto error1;

/* Update the parent high keys of the left block, if needed. */
if (tcur->bc_flags & XFS_BTREE_OVERLAPPING) {
- error = tcur->bc_ops->update_keys(tcur, level);
+ error = xfs_btree_update_keys(tcur, level);
if (error)
goto error1;
}
@@ -2633,13 +2602,13 @@ xfs_btree_rshift(

/* Update the parent high keys of the left block, if needed. */
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
- error = cur->bc_ops->update_keys(cur, level);
+ error = xfs_btree_update_keys(cur, level);
if (error)
goto error1;
}

/* Update the parent keys of the right block. */
- error = cur->bc_ops->update_keys(tcur, level);
+ error = xfs_btree_update_keys(tcur, level);
if (error)
goto error1;

@@ -2778,7 +2747,7 @@ __xfs_btree_split(
xfs_btree_log_ptrs(cur, rbp, 1, rrecs);

/* Stash the keys of the new block for later insertion. */
- cur->bc_ops->get_node_keys(cur, right, key);
+ xfs_btree_get_node_keys(cur, right, key);
} else {
/* It's a leaf. Move records. */
union xfs_btree_rec *lrp; /* left record pointer */
@@ -2792,7 +2761,7 @@ __xfs_btree_split(
xfs_btree_log_recs(cur, rbp, 1, rrecs);

/* Stash the keys of the new block for later insertion. */
- cur->bc_ops->get_leaf_keys(cur, right, key);
+ xfs_btree_get_leaf_keys(cur, right, key);
}

/*
@@ -2822,7 +2791,7 @@ __xfs_btree_split(

/* Update the parent high keys of the left block, if needed. */
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
- error = cur->bc_ops->update_keys(cur, level);
+ error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
}
@@ -3143,9 +3112,9 @@ xfs_btree_new_root(
* 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_get_node_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
- cur->bc_ops->get_node_keys(cur, right,
+ xfs_btree_get_node_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
} else {
/*
@@ -3153,9 +3122,9 @@ xfs_btree_new_root(
* directly in the parent block. Do the same for the right
* block.
*/
- cur->bc_ops->get_leaf_keys(cur, left,
+ xfs_btree_get_leaf_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
- cur->bc_ops->get_leaf_keys(cur, right,
+ xfs_btree_get_leaf_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
}
xfs_btree_log_keys(cur, nbp, 1, 2);
@@ -3434,7 +3403,7 @@ xfs_btree_insrec(
if (bp && bp->b_bn != old_bn) {
xfs_btree_get_keys(cur, block, lkey);
} else if (xfs_btree_needs_key_update(cur, optr)) {
- error = cur->bc_ops->update_keys(cur, level);
+ error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
}
@@ -3880,7 +3849,7 @@ xfs_btree_delrec(
* key values above us in the tree.
*/
if (xfs_btree_needs_key_update(cur, ptr)) {
- error = cur->bc_ops->update_keys(cur, level);
+ error = xfs_btree_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 9b6d628..04d0865 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -214,19 +214,6 @@ 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);
};

/*
@@ -527,17 +514,6 @@ 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);
-void xfs_btree_get_leaf_keys_overlapped(struct xfs_btree_cur *cur,
- struct xfs_btree_block *block, union xfs_btree_key *key);
-void xfs_btree_get_node_keys_overlapped(struct xfs_btree_cur *cur,
- struct xfs_btree_block *block, union xfs_btree_key *key);
-int xfs_btree_update_keys_overlapped(struct xfs_btree_cur *cur, int level);
-
/* return codes */
#define XFS_BTREE_QUERY_RANGE_CONTINUE 0 /* keep iterating */
#define XFS_BTREE_QUERY_RANGE_ABORT 1 /* stop iterating */
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index c83691e..31ca220 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -320,10 +320,6 @@ 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 = {
@@ -345,10 +341,6 @@ 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,
};

/*
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 232450c..bc1faeb 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -453,10 +453,6 @@ static const struct xfs_btree_ops xfs_rmapbt_ops = {
.keys_inorder = xfs_rmapbt_keys_inorder,
.recs_inorder = xfs_rmapbt_recs_inorder,
#endif
-
- .get_leaf_keys = xfs_btree_get_leaf_keys_overlapped,
- .get_node_keys = xfs_btree_get_node_keys_overlapped,
- .update_keys = xfs_btree_update_keys_overlapped,
};

/*