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bio_map_user_iov(): move alignment check into the main loop 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-09-23 16:23:18 -04:00
parent e2e115d18b
commit 98f0bc9905
1 changed files with 23 additions and 23 deletions
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46
block/bio.c
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@ -1344,11 +1344,6 @@ struct bio *bio_map_user_iov(struct request_queue *q,
return ERR_PTR(-EINVAL);
nr_pages += end - start;
/*
* buffer must be aligned to at least logical block size for now
*/
if (uaddr & queue_dma_alignment(q))
return ERR_PTR(-EINVAL);
}
if (!nr_pages)
@ -1373,29 +1368,34 @@ struct bio *bio_map_user_iov(struct request_queue *q,
npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
for (j = 0; j < npages; j++) {
unsigned int n = PAGE_SIZE - offs;
unsigned short prev_bi_vcnt = bio->bi_vcnt;
if (unlikely(offs & queue_dma_alignment(q))) {
ret = -EINVAL;
j = 0;
} else {
for (j = 0; j < npages; j++) {
struct page *page = pages[j];
unsigned int n = PAGE_SIZE - offs;
unsigned short prev_bi_vcnt = bio->bi_vcnt;
if (n > bytes)
n = bytes;
if (n > bytes)
n = bytes;
if (!bio_add_pc_page(q, bio, pages[j], n, offs))
break;
if (!bio_add_pc_page(q, bio, page, n, offs))
break;
/*
* check if vector was merged with previous
* drop page reference if needed
*/
if (bio->bi_vcnt == prev_bi_vcnt)
put_page(pages[j]);
/*
* check if vector was merged with previous
* drop page reference if needed
*/
if (bio->bi_vcnt == prev_bi_vcnt)
put_page(page);
added += n;
bytes -= n;
offs = 0;
added += n;
bytes -= n;
offs = 0;
}
iov_iter_advance(&i, added);
}
iov_iter_advance(&i, added);
/*
* release the pages we didn't map into the bio, if any
*/