[XFS] implement generic xfs_btree_update

From: Dave Chinner <dgc@sgi.com>

The most complicated part here is the lastrec tracking for the alloc
btree. Most logic is in the update_lastrec method which has to do some
hopefully good enough dirty magic to maintain it.

[hch: split out from bigger patch and a rework of the lastrec

logic]

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32194a

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, 18 insertions, 0 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 1296b4102e9..7d6c4ace805 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -430,6 +430,24 @@ xfs_bmbt_lookup_ge(
         return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
 }
 
+/*
+* Update the record referred to by cur to the value given
+ * by [off, bno, len, state].
+ * This either works (return 0) or gets an EFSCORRUPTED error.
+ */
+STATIC int
+xfs_bmbt_update(
+        struct xfs_btree_cur    *cur,
+        xfs_fileoff_t           off,
+        xfs_fsblock_t           bno,
+        xfs_filblks_t           len,
+        xfs_exntst_t            state)
+{
+        union xfs_btree_rec     rec;
+
+        xfs_bmbt_disk_set_allf(&rec.bmbt, off, bno, len, state);
+        return xfs_btree_update(cur, &rec);
+}
 
 /*
  * Called from xfs_bmap_add_attrfork to handle btree format files.