xfs: add a xfs_btree_init_ptr_from_cur

Inode-rooted btrees don't need to initialize the root pointer in the
->init_ptr_from_cur method as the root is found by the
xfs_btree_get_iroot method later.  Make ->init_ptr_from_cur option
for inode rooted btrees by providing a helper that does the right
thing for the given btree type and also documents the semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 5dad3db4affa04cde72f1b6b5640f49845486cc5..726cb506bbbfafa182ddef10939f2c5d1d3bb372 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -369,14 +369,6 @@ xfs_bmbt_init_rec_from_cur(
        xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
 }
 
-STATIC void
-xfs_bmbt_init_ptr_from_cur(
-       struct xfs_btree_cur    *cur,
-       union xfs_btree_ptr     *ptr)
-{
-       ptr->l = 0;
-}
-
 STATIC int64_t
 xfs_bmbt_key_diff(
        struct xfs_btree_cur            *cur,
@@ -544,7 +536,6 @@ const struct xfs_btree_ops xfs_bmbt_ops = {
        .init_key_from_rec      = xfs_bmbt_init_key_from_rec,
        .init_high_key_from_rec = xfs_bmbt_init_high_key_from_rec,
        .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_two_keys          = xfs_bmbt_diff_two_keys,
        .buf_ops                = &xfs_bmbt_buf_ops,

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 5d0b1084cba8b45978dd79bdb8b0416e5b706fa5..7c4f842c5f9130406a01fae1cf4784e9a4d205f3 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1881,6 +1881,25 @@ xfs_lookup_get_search_key(
        return xfs_btree_key_addr(cur, keyno, block);
 }
 
+/*
+ * Initialize a pointer to the root block.
+ */
+void
+xfs_btree_init_ptr_from_cur(
+       struct xfs_btree_cur    *cur,
+       union xfs_btree_ptr     *ptr)
+{
+       if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) {
+               /*
+                * Inode-rooted btrees call xfs_btree_get_iroot to find the root
+                * in xfs_btree_lookup_get_block and don't need a pointer here.
+                */
+               ptr->l = 0;
+       } else {
+               cur->bc_ops->init_ptr_from_cur(cur, ptr);
+       }
+}
+
 /*
  * Lookup the record.  The cursor is made to point to it, based on dir.
  * stat is set to 0 if can't find any such record, 1 for success.
@@ -1911,7 +1930,7 @@ xfs_btree_lookup(
        keyno = 0;
 
        /* initialise start pointer from cursor */
-       cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+       xfs_btree_init_ptr_from_cur(cur, &ptr);
        pp = &ptr;
 
        /*
@@ -3121,7 +3140,7 @@ xfs_btree_new_root(
        XFS_BTREE_STATS_INC(cur, newroot);
 
        /* initialise our start point from the cursor */
-       cur->bc_ops->init_ptr_from_cur(cur, &rptr);
+       xfs_btree_init_ptr_from_cur(cur, &rptr);
 
        /* Allocate the new block. If we can't do it, we're toast. Give up. */
        error = xfs_btree_alloc_block(cur, &rptr, &lptr, stat);
@@ -4430,7 +4449,7 @@ xfs_btree_visit_blocks(
        struct xfs_btree_block          *block = NULL;
        int                             error = 0;
 
-       cur->bc_ops->init_ptr_from_cur(cur, &lptr);
+       xfs_btree_init_ptr_from_cur(cur, &lptr);
 
        /* for each level */
        for (level = cur->bc_nlevels - 1; level >= 0; level--) {
@@ -4852,7 +4871,7 @@ xfs_btree_overlapped_query_range(
 
        /* Load the root of the btree. */
        level = cur->bc_nlevels - 1;
-       cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+       xfs_btree_init_ptr_from_cur(cur, &ptr);
        error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
        if (error)
                return error;

diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 07abc56e03954a76c4a1855b375da8050ec502a8..99194ae946948b26e6149e686741b2bba9aa7b3d 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -714,6 +714,8 @@ void xfs_btree_copy_ptrs(struct xfs_btree_cur *cur,
 void xfs_btree_copy_keys(struct xfs_btree_cur *cur,
                union xfs_btree_key *dst_key,
                const union xfs_btree_key *src_key, int numkeys);
+void xfs_btree_init_ptr_from_cur(struct xfs_btree_cur *cur,
+               union xfs_btree_ptr *ptr);
 
 static inline struct xfs_btree_cur *
 xfs_btree_alloc_cursor(

diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c
index a0dbe9b9b1c6c1bf2a5e550a6a5fc622d49696d9..36d8c584195615d61e878ecb83a59fc46aa225b8 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree_staging.c
+++ b/fs/xfs/libxfs/xfs_btree_staging.c
@@ -225,7 +225,6 @@ xfs_btree_stage_ifakeroot(
        memcpy(nops, cur->bc_ops, sizeof(struct xfs_btree_ops));
        nops->alloc_block = xfs_btree_fakeroot_alloc_block;
        nops->free_block = xfs_btree_fakeroot_free_block;
-       nops->init_ptr_from_cur = xfs_btree_fakeroot_init_ptr_from_cur;
        nops->dup_cursor = xfs_btree_fakeroot_dup_cursor;
 
        cur->bc_ino.ifake = ifake;

diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
index 71cfb2a45468239a5e1ad5812f96858c4ec1dc9f..1ec3339755b92ef6a8767c2d91175ebcfe6dc2a7 100644 (file)
--- a/fs/xfs/scrub/btree.c
+++ b/fs/xfs/scrub/btree.c
@@ -733,7 +733,7 @@ xchk_btree(
         * error codes for us.
         */
        level = cur->bc_nlevels - 1;
-       cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+       xfs_btree_init_ptr_from_cur(cur, &ptr);
        if (!xchk_btree_ptr_ok(bs, cur->bc_nlevels, &ptr))
                goto out;
        error = xchk_btree_get_block(bs, level, &ptr, &block, &bp);