diff options
| -rw-r--r-- | fs/xfs/xfs_buf_item.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 47549cfa61cd..0ee6fa9efd18 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -57,6 +57,10 @@ xfs_buf_log_format_size( (blfp->blf_map_size * sizeof(blfp->blf_data_map[0])); } +/* + * We only have to worry about discontiguous buffer range straddling on unmapped + * buffers. Everything else will have a contiguous data region we can copy from. + */ static inline bool xfs_buf_item_straddle( struct xfs_buf *bp, @@ -66,6 +70,9 @@ xfs_buf_item_straddle( { void *first, *last; + if (bp->b_page_count == 1 || !(bp->b_flags & XBF_UNMAPPED)) + return false; + first = xfs_buf_offset(bp, offset + (first_bit << XFS_BLF_SHIFT)); last = xfs_buf_offset(bp, offset + ((first_bit + nbits) << XFS_BLF_SHIFT)); @@ -133,11 +140,13 @@ xfs_buf_item_size_segment( return; slow_scan: - /* Count the first bit we jumped out of the above loop from */ - (*nvecs)++; - *nbytes += XFS_BLF_CHUNK; + ASSERT(bp->b_addr == NULL); last_bit = first_bit; + nbits = 1; while (last_bit != -1) { + + *nbytes += XFS_BLF_CHUNK; + /* * This takes the bit number to start looking from and * returns the next set bit from there. It returns -1 @@ -152,6 +161,8 @@ slow_scan: * else keep scanning the current set of bits. */ if (next_bit == -1) { + if (first_bit != last_bit) + (*nvecs)++; break; } else if (next_bit != last_bit + 1 || xfs_buf_item_straddle(bp, offset, first_bit, nbits)) { @@ -163,7 +174,6 @@ slow_scan: last_bit++; nbits++; } - *nbytes += XFS_BLF_CHUNK; } } |