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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-12-18 14:49:37 +0900
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2009-01-02 11:10:08 -0600
commit56c451f4b583ccdf80c9e676179c9cb49de86745 (patch)
tree7ad9daeafb88e3c4390bf7a2db0c203fe2642728
parente623ddb4e940b266adc77ba1cc28a3554aa90e79 (diff)
downloadkernel-56c451f4b583ccdf80c9e676179c9cb49de86745.tar.gz
[SCSI] block: fix the partial mappings with struct rq_map_data
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>
-rw-r--r--block/blk-map.c3
-rw-r--r--drivers/scsi/sg.c1
-rw-r--r--fs/bio.c12
-rw-r--r--include/linux/blkdev.h1
4 files changed, 14 insertions, 3 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index 2990447f45e9..c7e55b23a2bc 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -150,6 +150,9 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
bio = rq->bio;
bytes_read += ret;
ubuf += ret;
+
+ if (map_data)
+ map_data->offset += ret;
}
if (!bio_flagged(bio, BIO_USER_MAPPED))
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 5103855242ae..7d0b3d9ee43b 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1669,6 +1669,7 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
md->pages = req_schp->pages;
md->page_order = req_schp->page_order;
md->nr_entries = req_schp->k_use_sg;
+ md->offset = 0;
}
if (iov_count)
diff --git a/fs/bio.c b/fs/bio.c
index 356e7423b923..13be075806b6 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -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)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7035cec583b6..811e5342c452 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -690,6 +690,7 @@ struct rq_map_data {
struct page **pages;
int page_order;
int nr_entries;
+ unsigned long offset;
};
struct req_iterator {