diff options
| -rw-r--r-- | block/blk-merge.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 247b17f2a0f6..21e87a714a73 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -474,9 +474,21 @@ static unsigned blk_bvec_map_sg(struct request_queue *q, while (nbytes > 0) { unsigned offset = bvec->bv_offset + total; unsigned len = min(get_max_segment_size(q, offset), nbytes); + struct page *page = bvec->bv_page; + + /* + * Unfortunately a fair number of drivers barf on scatterlists + * that have an offset larger than PAGE_SIZE, despite other + * subsystems dealing with that invariant just fine. For now + * stick to the legacy format where we never present those from + * the block layer, but the code below should be removed once + * these offenders (mostly MMC/SD drivers) are fixed. + */ + page += (offset >> PAGE_SHIFT); + offset &= ~PAGE_MASK; *sg = blk_next_sg(sg, sglist); - sg_set_page(*sg, bvec->bv_page, len, offset); + sg_set_page(*sg, page, len, offset); total += len; nbytes -= len; |