[XFS] implement generic xfs_btree_lookup
From: Dave Chinner <dgc@sgi.com>
[hch: split out from bigger patch and minor adaptions]
SGI-PV: 985583
SGI-Modid: xfs-linux-melb:xfs-kern:32192a
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>
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 7ca6903..6bda0ae 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -90,6 +90,54 @@
*/
/*
+ * Lookup the record equal to [bno, len] in the btree given by cur.
+ */
+STATIC int /* error */
+xfs_alloc_lookup_eq(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t bno, /* starting block of extent */
+ xfs_extlen_t len, /* length of extent */
+ int *stat) /* success/failure */
+{
+ cur->bc_rec.a.ar_startblock = bno;
+ cur->bc_rec.a.ar_blockcount = len;
+ return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
+}
+
+/*
+ * Lookup the first record greater than or equal to [bno, len]
+ * in the btree given by cur.
+ */
+STATIC int /* error */
+xfs_alloc_lookup_ge(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t bno, /* starting block of extent */
+ xfs_extlen_t len, /* length of extent */
+ int *stat) /* success/failure */
+{
+ cur->bc_rec.a.ar_startblock = bno;
+ cur->bc_rec.a.ar_blockcount = len;
+ return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
+}
+
+/*
+ * Lookup the first record less than or equal to [bno, len]
+ * in the btree given by cur.
+ */
+STATIC int /* error */
+xfs_alloc_lookup_le(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t bno, /* starting block of extent */
+ xfs_extlen_t len, /* length of extent */
+ int *stat) /* success/failure */
+{
+ cur->bc_rec.a.ar_startblock = bno;
+ cur->bc_rec.a.ar_blockcount = len;
+ return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
+}
+
+
+/*
* Compute aligned version of the found extent.
* Takes alignment and min length into account.
*/