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[SCSI] block: fix the partial mappings with struct rq_map_data

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This fixes bio_copy_user_iov to properly handle the partial mappings
with struct rq_map_data (which only sg uses for now but st and osst
will shortly). It adds the offset member to struct rq_map_data and
changes blk_rq_map_user to update it so that bio_copy_user_iov can add
an appropriate page frame via bio_add_pc_page().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
FUJITA Tomonori
2008-12-18 14:49:37 +09:00
committed by James Bottomley
parent e623ddb4e9
commit 56c451f4b5
4 changed files with 14 additions and 3 deletions
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12
fs/bio.c
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@@ -788,6 +788,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
int i, ret;
int nr_pages = 0;
unsigned int len = 0;
unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
for (i = 0; i < iov_count; i++) {
unsigned long uaddr;
@@ -814,12 +815,16 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
bio->bi_rw |= (!write_to_vm << BIO_RW);
ret = 0;
i = 0;
if (map_data)
if (map_data) {
nr_pages = 1 << map_data->page_order;
i = map_data->offset / PAGE_SIZE;
}
while (len) {
unsigned int bytes = PAGE_SIZE;
bytes -= offset;
if (bytes > len)
bytes = len;
@@ -841,10 +846,11 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
}
}
if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
break;
len -= bytes;
offset = 0;
}
if (ret)