xfs: use b_maps[] for discontiguous buffers
Commits starting at 77c1a08 introduced a multiple segment support
to xfs_buf. xfs_trans_buf_item_match() could not find a multi-segment
buffer in the transaction because it was looking at the single segment
block number rather than the multi-segment b_maps[0].bm.bn. This
results on a recursive buffer lock that can never be satisfied.
This patch:
1) Changed the remaining b_map accesses to be b_maps[0] accesses.
2) Renames the single segment b_map structure to __b_map to avoid
future confusion.
Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 23f5642..433a12e 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -151,7 +151,7 @@
struct page **b_pages; /* array of page pointers */
struct page *b_page_array[XB_PAGES]; /* inline pages */
struct xfs_buf_map *b_maps; /* compound buffer map */
- struct xfs_buf_map b_map; /* inline compound buffer map */
+ struct xfs_buf_map __b_map; /* inline compound buffer map */
int b_map_count;
int b_io_length; /* IO size in BBs */
atomic_t b_pin_count; /* pin count */
@@ -330,8 +330,8 @@
* In future, uncached buffers will pass the block number directly to the io
* request function and hence these macros will go away at that point.
*/
-#define XFS_BUF_ADDR(bp) ((bp)->b_map.bm_bn)
-#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_map.bm_bn = (xfs_daddr_t)(bno))
+#define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn)
+#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
{