[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, 14 insertions, 0 deletions

diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index ac3f527b0ac4..c3bfa5556c19 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -187,6 +187,12 @@ struct xfs_btree_ops {
         /* cursor operations */
         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 
+        /* update last record information */
+        void    (*update_lastrec)(struct xfs_btree_cur *cur,
+                                  struct xfs_btree_block *block,
+                                  union xfs_btree_rec *rec,
+                                  int ptr, int reason);
+
         /* records in block/level */
         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 
@@ -221,6 +227,12 @@ struct xfs_btree_ops {
 };
 
 /*
+ * Reasons for the update_lastrec method to be called.
+ */
+#define LASTREC_UPDATE  0
+
+
+/*
  * Btree cursor structure.
  * This collects all information needed by the btree code in one place.
  */
@@ -264,6 +276,7 @@ typedef struct xfs_btree_cur
 /* cursor flags */
 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
+#define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 
 
 #define XFS_BTREE_NOERROR       0
@@ -519,6 +532,7 @@ int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 int xfs_btree_updkey(struct xfs_btree_cur *, union xfs_btree_key *, int);
+int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 
 /*
  * Helpers.