[XFS] implement generic xfs_btree_get_rec

Not really much reason to make it generic given that it's so small, but
this is the last non-method in xfs_alloc_btree.c and xfs_ialloc_btree.c,
so it makes the whole btree implementation more structured.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32206a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 28cc76818343..8503ed5d10a0 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -3764,3 +3764,44 @@ error0:
         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
         return error;
 }
+
+/*
+ * Get the data from the pointed-to record.
+ */
+int                                     /* error */
+xfs_btree_get_rec(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        union xfs_btree_rec     **recp, /* output: btree record */
+        int                     *stat)  /* output: success/failure */
+{
+        struct xfs_btree_block  *block; /* btree block */
+        struct xfs_buf          *bp;    /* buffer pointer */
+        int                     ptr;    /* record number */
+#ifdef DEBUG
+        int                     error;  /* error return value */
+#endif
+
+        ptr = cur->bc_ptrs[0];
+        block = xfs_btree_get_block(cur, 0, &bp);
+
+#ifdef DEBUG
+        error = xfs_btree_check_block(cur, block, 0, bp);
+        if (error)
+                return error;
+#endif
+
+        /*
+         * Off the right end or left end, return failure.
+         */
+        if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
+                *stat = 0;
+                return 0;
+        }
+
+        /*
+         * Point to the record and extract its data.
+         */
+        *recp = xfs_btree_rec_addr(cur, ptr, block);
+        *stat = 1;
+        return 0;
+}