[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, 20 insertions, 0 deletions

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index bbf537f64c41..138651afd44f 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -172,6 +172,26 @@ xfs_inobt_lookup_le(
 }
 
 /*
+ * Update the record referred to by cur to the value given
+ * by [ino, fcnt, free].
+ * This either works (return 0) or gets an EFSCORRUPTED error.
+ */
+STATIC int                              /* error */
+xfs_inobt_update(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        xfs_agino_t             ino,    /* starting inode of chunk */
+        __int32_t               fcnt,   /* free inode count */
+        xfs_inofree_t           free)   /* free inode mask */
+{
+        union xfs_btree_rec     rec;
+
+        rec.inobt.ir_startino = cpu_to_be32(ino);
+        rec.inobt.ir_freecount = cpu_to_be32(fcnt);
+        rec.inobt.ir_free = cpu_to_be64(free);
+        return xfs_btree_update(cur, &rec);
+}
+
+/*
  * Allocate new inodes in the allocation group specified by agbp.
  * Return 0 for success, else error code.
  */