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.c b/fs/xfs/xfs_buf.c
index 26673a0..56d1614 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -175,7 +175,7 @@
bp->b_map_count = map_count;
if (map_count == 1) {
- bp->b_maps = &bp->b_map;
+ bp->b_maps = &bp->__b_map;
return 0;
}
@@ -193,7 +193,7 @@
xfs_buf_free_maps(
struct xfs_buf *bp)
{
- if (bp->b_maps != &bp->b_map) {
+ if (bp->b_maps != &bp->__b_map) {
kmem_free(bp->b_maps);
bp->b_maps = NULL;
}
@@ -377,8 +377,8 @@
}
use_alloc_page:
- start = BBTOB(bp->b_map.bm_bn) >> PAGE_SHIFT;
- end = (BBTOB(bp->b_map.bm_bn + bp->b_length) + PAGE_SIZE - 1)
+ start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT;
+ end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1)
>> PAGE_SHIFT;
page_count = end - start;
error = _xfs_buf_get_pages(bp, page_count, flags);
@@ -640,7 +640,7 @@
xfs_buf_flags_t flags)
{
ASSERT(!(flags & XBF_WRITE));
- ASSERT(bp->b_map.bm_bn != XFS_BUF_DADDR_NULL);
+ ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL);
bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD);
bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD);
@@ -1709,7 +1709,7 @@
struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list);
xfs_daddr_t diff;
- diff = ap->b_map.bm_bn - bp->b_map.bm_bn;
+ diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn;
if (diff < 0)
return -1;
if (diff > 0)