xfs: add discontiguous buffer support to transactions

Now that the buffer cache supports discontiguous buffers, add
support to the transaction buffer interface for getting and reading
buffers.

Note that this patch does not convert the buffer item logging to
support discontiguous buffers. That will be done as a separate
commit.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 45 insertions, 5 deletions

diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 7c37b533aa8..bc2afd52a0b 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -448,11 +448,51 @@ xfs_trans_t	*xfs_trans_dup(xfs_trans_t *);
 int             xfs_trans_reserve(xfs_trans_t *, uint, uint, uint,
                                   uint, uint);
 void            xfs_trans_mod_sb(xfs_trans_t *, uint, int64_t);
-struct xfs_buf  *xfs_trans_get_buf(xfs_trans_t *, struct xfs_buftarg *, xfs_daddr_t,
-                                   int, uint);
-int             xfs_trans_read_buf(struct xfs_mount *, xfs_trans_t *,
-                                   struct xfs_buftarg *, xfs_daddr_t, int, uint,
-                                   struct xfs_buf **);
+
+struct xfs_buf  *xfs_trans_get_buf_map(struct xfs_trans *tp,
+                                       struct xfs_buftarg *target,
+                                       struct xfs_buf_map *map, int nmaps,
+                                       uint flags);
+
+static inline struct xfs_buf *
+xfs_trans_get_buf(
+        struct xfs_trans        *tp,
+        struct xfs_buftarg      *target,
+        xfs_daddr_t             blkno,
+        int                     numblks,
+        uint                    flags)
+{
+        struct xfs_buf_map      map = {
+                .bm_bn = blkno,
+                .bm_len = numblks,
+        };
+        return xfs_trans_get_buf_map(tp, target, &map, 1, flags);
+}
+
+int             xfs_trans_read_buf_map(struct xfs_mount *mp,
+                                       struct xfs_trans *tp,
+                                       struct xfs_buftarg *target,
+                                       struct xfs_buf_map *map, int nmaps,
+                                       xfs_buf_flags_t flags,
+                                       struct xfs_buf **bpp);
+
+static inline int
+xfs_trans_read_buf(
+        struct xfs_mount        *mp,
+        struct xfs_trans        *tp,
+        struct xfs_buftarg      *target,
+        xfs_daddr_t             blkno,
+        int                     numblks,
+        xfs_buf_flags_t         flags,
+        struct xfs_buf          **bpp)
+{
+        struct xfs_buf_map      map = {
+                .bm_bn = blkno,
+                .bm_len = numblks,
+        };
+        return xfs_trans_read_buf_map(mp, tp, target, &map, 1, flags, bpp);
+}
+
 struct xfs_buf  *xfs_trans_getsb(xfs_trans_t *, struct xfs_mount *, int);
 
 void            xfs_trans_brelse(xfs_trans_t *, struct xfs_buf *);