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| author | Jens Axboe <axboe@fb.com> | 2014-06-25 02:22:24 +0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-06-25 02:22:24 +0400 |
| commit | 66cb45aa41315d1d9972cada354fbdf7870d7714 (patch) | |
| tree | 5ca5ef3c31f24a7a11989d8a6a163eed9aaf9528 /block/bio.c | |
| parent | 3a4b0eda8e4b27e6aca86f9f4d327c1070815e30 (diff) | |
| download | linux-66cb45aa41315d1d9972cada354fbdf7870d7714.tar.xz | |
block: add support for limiting gaps in SG lists
Another restriction inherited for NVMe - those devices don't support
SG lists that have "gaps" in them. Gaps refers to cases where the
previous SG entry doesn't end on a page boundary. For NVMe, all SG
entries must start at offset 0 (except the first) and end on a page
boundary (except the last).
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c index 8c2e55e39a1b..0ec61c9e536c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -746,6 +746,14 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page goto done; } + + /* + * If the queue doesn't support SG gaps and adding this + * offset would create a gap, disallow it. + */ + if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && + bvec_gap_to_prev(prev, offset)) + return 0; } if (bio->bi_vcnt >= bio->bi_max_vecs) |