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| author | Tejun Heo <htejun@gmail.com> | 2008-03-04 11:18:17 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-03-04 11:18:17 +0100 |
| commit | e3790c7d42a545e8fe8b38b513613ca96687b670 (patch) | |
| tree | 0b849ba46007c4d7f7a34271a76d58e7406cbad7 /block/blk-map.c | |
| parent | 7a85f8896f4b4a4a0249563b92af9e3161a6b467 (diff) | |
| download | linux-3.10-e3790c7d42a545e8fe8b38b513613ca96687b670.tar.gz linux-3.10-e3790c7d42a545e8fe8b38b513613ca96687b670.tar.bz2 linux-3.10-e3790c7d42a545e8fe8b38b513613ca96687b670.zip | |
block: separate out padding from alignment
Block layer alignment was used for two different purposes - memory
alignment and padding. This causes problems in lower layers because
drivers which only require memory alignment ends up with adjusted
rq->data_len. Separate out padding such that padding occurs iff
driver explicitly requests it.
Tomo: restorethe code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa
according to padding alignment.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-map.c')
| -rw-r--r-- | block/blk-map.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index f5598322954..4e17dfd0035 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -43,6 +43,7 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq, void __user *ubuf, unsigned int len) { unsigned long uaddr; + unsigned int alignment; struct bio *bio, *orig_bio; int reading, ret; @@ -53,8 +54,8 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq, * direct dma. else, set up kernel bounce buffers */ uaddr = (unsigned long) ubuf; - if (!(uaddr & queue_dma_alignment(q)) && - !(len & queue_dma_alignment(q))) + alignment = queue_dma_alignment(q) | q->dma_pad_mask; + if (!(uaddr & alignment) && !(len & alignment)) bio = bio_map_user(q, NULL, uaddr, len, reading); else bio = bio_copy_user(q, uaddr, len, reading); @@ -141,15 +142,20 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, /* * __blk_rq_map_user() copies the buffers if starting address - * or length isn't aligned. As the copied buffer is always - * page aligned, we know that there's enough room for padding. - * Extend the last bio and update rq->data_len accordingly. + * or length isn't aligned to dma_pad_mask. As the copied + * buffer is always page aligned, we know that there's enough + * room for padding. Extend the last bio and update + * rq->data_len accordingly. * * On unmap, bio_uncopy_user() will use unmodified * bio_map_data pointed to by bio->bi_private. */ - if (len & queue_dma_alignment(q)) { - unsigned int pad_len = (queue_dma_alignment(q) & ~len) + 1; + if (len & q->dma_pad_mask) { + unsigned int pad_len = (q->dma_pad_mask & ~len) + 1; + struct bio *bio = rq->biotail; + + bio->bi_io_vec[bio->bi_vcnt - 1].bv_len += pad_len; + bio->bi_size += pad_len; rq->extra_len += pad_len; } |