xfs: add function pointers for get/update keys to the btree

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>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

5 files changed, 135 insertions, 64 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index 5ba2dac5e67c..c60eeb826b9d 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -403,6 +403,10 @@ 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 714b387e11ad..4f1a98e6fb54 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -757,6 +757,10 @@ 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 8d8e3625c365..405442d8e780 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1879,24 +1879,73 @@ 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);
+}
+
+/* Derive the keys for any btree block. */
+STATIC void
+xfs_btree_get_keys(
+        struct xfs_btree_cur    *cur,
+        struct xfs_btree_block  *block,
+        union xfs_btree_key     *key)
+{
+        if (be16_to_cpu(block->bb_level) == 0)
+                cur->bc_ops->get_leaf_keys(cur, block, key);
+        else
+                cur->bc_ops->get_node_keys(cur, block, key);
+}
+
 /*
- * Update keys at all levels from here to the root along the cursor's path.
+ * Decide if we need to update the parent keys of a btree block.  For
+ * a standard btree this is only necessary if we're updating the first
+ * record/key.
  */
-STATIC int
-xfs_btree_updkey(
+static inline bool
+xfs_btree_needs_key_update(
+        struct xfs_btree_cur    *cur,
+        int                     ptr)
+{
+        return ptr == 1;
+}
+
+/*
+ * Update the parent keys of the given level, progressing towards the root.
+ */
+int
+xfs_btree_update_keys(
         struct xfs_btree_cur    *cur,
-        union xfs_btree_key     *keyp,
         int                     level)
 {
         struct xfs_btree_block  *block;
         struct xfs_buf          *bp;
         union xfs_btree_key     *kp;
+        union xfs_btree_key     key;
         int                     ptr;
 
         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
         XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
 
-        ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
+        ASSERT(level >= 0);
 
         /*
          * Go up the tree from this level toward the root.
@@ -1904,7 +1953,9 @@ xfs_btree_updkey(
          * Stop when we reach a level where the cursor isn't pointing
          * at the first entry in the block.
          */
-        for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
+        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
                 int             error;
 #endif
@@ -1918,7 +1969,7 @@ xfs_btree_updkey(
 #endif
                 ptr = cur->bc_ptrs[level];
                 kp = xfs_btree_key_addr(cur, ptr, block);
-                xfs_btree_copy_keys(cur, kp, keyp, 1);
+                xfs_btree_copy_keys(cur, kp, &key, 1);
                 xfs_btree_log_keys(cur, bp, ptr, ptr);
         }
 
@@ -1971,11 +2022,8 @@ xfs_btree_update(
         }
 
         /* Updating first rec in leaf. Pass new key value up to our parent. */
-        if (ptr == 1) {
-                union xfs_btree_key     key;
-
-                cur->bc_ops->init_key_from_rec(&key, rec);
-                error = xfs_btree_updkey(cur, &key, 1);
+        if (xfs_btree_needs_key_update(cur, ptr)) {
+                error = cur->bc_ops->update_keys(cur, 0);
                 if (error)
                         goto error0;
         }
@@ -2146,11 +2194,10 @@ xfs_btree_lshift(
                  */
                 cur->bc_ops->init_key_from_rec(&key,
                         xfs_btree_rec_addr(cur, 1, right));
-                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);
         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;
 
                 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 b4f3035ae05e..e097e60400d8 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 88da2ad939d4..a48f4482004c 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,
 };
 
 /*