xfs: during btree split, save new block key & ptr for future insertion

When a btree block has to be split, we pass the new block's ptr from
xfs_btree_split() back to xfs_btree_insert() via a pointer parameter;
however, we pass the block's key through the cursor's record.  It is a
little weird to "initialize" a record from a key since the non-key
attributes will have garbage values.

When we go to add support for interval queries, we have to be able to
pass the lowest and highest keys accessible via a pointer.  There's no
clean way to pass this back through the cursor's record field.
Therefore, pass the key directly back to xfs_btree_insert() the same
way that we pass the btree_ptr.

As a bonus, we no longer need init_rec_from_key and can drop it from the
codebase.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

5 files changed, 20 insertions, 56 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index d9b42425291e..5ba2dac5e67c 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -212,17 +212,6 @@ xfs_allocbt_init_key_from_rec(
 }
 
 STATIC void
-xfs_allocbt_init_rec_from_key(
-        union xfs_btree_key     *key,
-        union xfs_btree_rec     *rec)
-{
-        ASSERT(key->alloc.ar_startblock != 0);
-
-        rec->alloc.ar_startblock = key->alloc.ar_startblock;
-        rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
-}
-
-STATIC void
 xfs_allocbt_init_rec_from_cur(
         struct xfs_btree_cur    *cur,
         union xfs_btree_rec     *rec)
@@ -406,7 +395,6 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
         .get_minrecs            = xfs_allocbt_get_minrecs,
         .get_maxrecs            = xfs_allocbt_get_maxrecs,
         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
-        .init_rec_from_key      = xfs_allocbt_init_rec_from_key,
         .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
         .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
         .key_diff               = xfs_allocbt_key_diff,
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index db0c71e470c9..714b387e11ad 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -600,17 +600,6 @@ xfs_bmbt_init_key_from_rec(
 }
 
 STATIC void
-xfs_bmbt_init_rec_from_key(
-        union xfs_btree_key     *key,
-        union xfs_btree_rec     *rec)
-{
-        ASSERT(key->bmbt.br_startoff != 0);
-
-        xfs_bmbt_disk_set_allf(&rec->bmbt, be64_to_cpu(key->bmbt.br_startoff),
-                               0, 0, XFS_EXT_NORM);
-}
-
-STATIC void
 xfs_bmbt_init_rec_from_cur(
         struct xfs_btree_cur    *cur,
         union xfs_btree_rec     *rec)
@@ -760,7 +749,6 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
         .get_minrecs            = xfs_bmbt_get_minrecs,
         .get_dmaxrecs           = xfs_bmbt_get_dmaxrecs,
         .init_key_from_rec      = xfs_bmbt_init_key_from_rec,
-        .init_rec_from_key      = xfs_bmbt_init_rec_from_key,
         .init_rec_from_cur      = xfs_bmbt_init_rec_from_cur,
         .init_ptr_from_cur      = xfs_bmbt_init_ptr_from_cur,
         .key_diff               = xfs_bmbt_key_diff,
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index f5ff95a18e9d..8d8e3625c365 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -2858,10 +2858,9 @@ 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_rec     *nrec,  /* new record */
+        union xfs_btree_key     *key, /* key of new block */
         int                     *stat)
 {
-        union xfs_btree_key     key;    /* new btree key value */
         int                     error = 0;
 
         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
@@ -2907,13 +2906,12 @@ xfs_btree_make_block_unfull(
          * If this works we have to re-set our variables because we
          * could be in a different block now.
          */
-        error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
+        error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
         if (error || *stat == 0)
                 return error;
 
 
         *index = cur->bc_ptrs[level];
-        cur->bc_ops->init_rec_from_key(&key, nrec);
         return 0;
 }
 
@@ -2926,16 +2924,16 @@ xfs_btree_insrec(
         struct xfs_btree_cur    *cur,   /* btree cursor */
         int                     level,  /* level to insert record at */
         union xfs_btree_ptr     *ptrp,  /* i/o: block number inserted */
-        union xfs_btree_rec     *recp,  /* i/o: record data inserted */
+        union xfs_btree_rec     *rec,   /* record to insert */
+        union xfs_btree_key     *key,   /* i/o: block key for ptrp */
         struct xfs_btree_cur    **curp, /* output: new cursor replacing cur */
         int                     *stat)  /* success/failure */
 {
         struct xfs_btree_block  *block; /* btree block */
         struct xfs_buf          *bp;    /* buffer for block */
-        union xfs_btree_key     key;    /* btree key */
         union xfs_btree_ptr     nptr;   /* new block ptr */
         struct xfs_btree_cur    *ncur;  /* new btree cursor */
-        union xfs_btree_rec     nrec;   /* new record count */
+        union xfs_btree_key     nkey;   /* new block key */
         int                     optr;   /* old key/record index */
         int                     ptr;    /* key/record index */
         int                     numrecs;/* number of records */
@@ -2945,7 +2943,7 @@ xfs_btree_insrec(
 #endif
 
         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
-        XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
+        XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, &rec);
 
         ncur = NULL;
 
@@ -2970,9 +2968,6 @@ xfs_btree_insrec(
                 return 0;
         }
 
-        /* Make a key out of the record data to be inserted, and save it. */
-        cur->bc_ops->init_key_from_rec(&key, recp);
-
         optr = ptr;
 
         XFS_BTREE_STATS_INC(cur, insrec);
@@ -2989,10 +2984,10 @@ xfs_btree_insrec(
         /* Check that the new entry is being inserted in the right place. */
         if (ptr <= numrecs) {
                 if (level == 0) {
-                        ASSERT(cur->bc_ops->recs_inorder(cur, recp,
+                        ASSERT(cur->bc_ops->recs_inorder(cur, rec,
                                 xfs_btree_rec_addr(cur, ptr, block)));
                 } else {
-                        ASSERT(cur->bc_ops->keys_inorder(cur, &key,
+                        ASSERT(cur->bc_ops->keys_inorder(cur, key,
                                 xfs_btree_key_addr(cur, ptr, block)));
                 }
         }
@@ -3005,7 +3000,7 @@ xfs_btree_insrec(
         xfs_btree_set_ptr_null(cur, &nptr);
         if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
                 error = xfs_btree_make_block_unfull(cur, level, numrecs,
-                                        &optr, &ptr, &nptr, &ncur, &nrec, stat);
+                                        &optr, &ptr, &nptr, &ncur, &nkey, stat);
                 if (error || *stat == 0)
                         goto error0;
         }
@@ -3055,7 +3050,7 @@ xfs_btree_insrec(
 #endif
 
                 /* Now put the new data in, bump numrecs and log it. */
-                xfs_btree_copy_keys(cur, kp, &key, 1);
+                xfs_btree_copy_keys(cur, kp, key, 1);
                 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
                 numrecs++;
                 xfs_btree_set_numrecs(block, numrecs);
@@ -3076,7 +3071,7 @@ xfs_btree_insrec(
                 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
 
                 /* Now put the new data in, bump numrecs and log it. */
-                xfs_btree_copy_recs(cur, rp, recp, 1);
+                xfs_btree_copy_recs(cur, rp, rec, 1);
                 xfs_btree_set_numrecs(block, ++numrecs);
                 xfs_btree_log_recs(cur, bp, ptr, numrecs);
 #ifdef DEBUG
@@ -3092,7 +3087,7 @@ xfs_btree_insrec(
 
         /* If we inserted at the start of a block, update the parents' keys. */
         if (optr == 1) {
-                error = xfs_btree_updkey(cur, &key, level + 1);
+                error = xfs_btree_updkey(cur, key, level + 1);
                 if (error)
                         goto error0;
         }
@@ -3102,7 +3097,7 @@ xfs_btree_insrec(
          * we are at the far right edge of the tree, update it.
          */
         if (xfs_btree_is_lastrec(cur, block, level)) {
-                cur->bc_ops->update_lastrec(cur, block, recp,
+                cur->bc_ops->update_lastrec(cur, block, rec,
                                             ptr, LASTREC_INSREC);
         }
 
@@ -3112,7 +3107,7 @@ xfs_btree_insrec(
          */
         *ptrp = nptr;
         if (!xfs_btree_ptr_is_null(cur, &nptr)) {
-                *recp = nrec;
+                *key = nkey;
                 *curp = ncur;
         }
 
@@ -3143,6 +3138,7 @@ xfs_btree_insert(
         union xfs_btree_ptr     nptr;   /* new block number (split result) */
         struct xfs_btree_cur    *ncur;  /* new cursor (split result) */
         struct xfs_btree_cur    *pcur;  /* previous level's cursor */
+        union xfs_btree_key     key;    /* key of block to insert */
         union xfs_btree_rec     rec;    /* record to insert */
 
         level = 0;
@@ -3150,7 +3146,10 @@ xfs_btree_insert(
         pcur = cur;
 
         xfs_btree_set_ptr_null(cur, &nptr);
+
+        /* Make a key out of the record data to be inserted, and save it. */
         cur->bc_ops->init_rec_from_cur(cur, &rec);
+        cur->bc_ops->init_key_from_rec(&key, &rec);
 
         /*
          * Loop going up the tree, starting at the leaf level.
@@ -3162,7 +3161,8 @@ xfs_btree_insert(
                  * Insert nrec/nptr into this level of the tree.
                  * Note if we fail, nptr will be null.
                  */
-                error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
+                error = xfs_btree_insrec(pcur, level, &nptr, &rec, &key,
+                                &ncur, &i);
                 if (error) {
                         if (pcur != cur)
                                 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 785a99682159..b4f3035ae05e 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -158,8 +158,6 @@ struct xfs_btree_ops {
         /* init values of btree structures */
         void    (*init_key_from_rec)(union xfs_btree_key *key,
                                      union xfs_btree_rec *rec);
-        void    (*init_rec_from_key)(union xfs_btree_key *key,
-                                     union xfs_btree_rec *rec);
         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
                                      union xfs_btree_rec *rec);
         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index 89c21d771e35..88da2ad939d4 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -146,14 +146,6 @@ xfs_inobt_init_key_from_rec(
 }
 
 STATIC void
-xfs_inobt_init_rec_from_key(
-        union xfs_btree_key     *key,
-        union xfs_btree_rec     *rec)
-{
-        rec->inobt.ir_startino = key->inobt.ir_startino;
-}
-
-STATIC void
 xfs_inobt_init_rec_from_cur(
         struct xfs_btree_cur    *cur,
         union xfs_btree_rec     *rec)
@@ -314,7 +306,6 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
         .get_minrecs            = xfs_inobt_get_minrecs,
         .get_maxrecs            = xfs_inobt_get_maxrecs,
         .init_key_from_rec      = xfs_inobt_init_key_from_rec,
-        .init_rec_from_key      = xfs_inobt_init_rec_from_key,
         .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
         .init_ptr_from_cur      = xfs_inobt_init_ptr_from_cur,
         .key_diff               = xfs_inobt_key_diff,
@@ -336,7 +327,6 @@ static const struct xfs_btree_ops xfs_finobt_ops = {
         .get_minrecs            = xfs_inobt_get_minrecs,
         .get_maxrecs            = xfs_inobt_get_maxrecs,
         .init_key_from_rec      = xfs_inobt_init_key_from_rec,
-        .init_rec_from_key      = xfs_inobt_init_rec_from_key,
         .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
         .init_ptr_from_cur      = xfs_finobt_init_ptr_from_cur,
         .key_diff               = xfs_inobt_key_diff,