[SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITE
The commit 818827669d85b84241696ffef2de485db46b0b5e (block: make
blk_rq_map_user take a NULL user-space buffer) extended
blk_rq_map_user to accept a NULL user-space buffer with a READ
command. It was necessary to convert sg to use the block layer mapping
API.
This patch extends blk_rq_map_user again for a WRITE command. It is
necessary to convert st and osst drivers to use the block layer
apping API.
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>
diff --git a/block/blk-map.c b/block/blk-map.c
index c7e55b2..f103729 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -42,7 +42,7 @@
static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
struct rq_map_data *map_data, void __user *ubuf,
- unsigned int len, int null_mapped, gfp_t gfp_mask)
+ unsigned int len, gfp_t gfp_mask)
{
unsigned long uaddr;
struct bio *bio, *orig_bio;
@@ -63,7 +63,7 @@
if (IS_ERR(bio))
return PTR_ERR(bio);
- if (null_mapped)
+ if (map_data && map_data->null_mapped)
bio->bi_flags |= (1 << BIO_NULL_MAPPED);
orig_bio = bio;
@@ -114,17 +114,15 @@
{
unsigned long bytes_read = 0;
struct bio *bio = NULL;
- int ret, null_mapped = 0;
+ int ret;
if (len > (q->max_hw_sectors << 9))
return -EINVAL;
if (!len)
return -EINVAL;
- if (!ubuf) {
- if (!map_data || rq_data_dir(rq) != READ)
- return -EINVAL;
- null_mapped = 1;
- }
+
+ if (!ubuf && (!map_data || !map_data->null_mapped))
+ return -EINVAL;
while (bytes_read != len) {
unsigned long map_len, end, start;
@@ -143,7 +141,7 @@
map_len -= PAGE_SIZE;
ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
- null_mapped, gfp_mask);
+ gfp_mask);
if (ret < 0)
goto unmap_rq;
if (!bio)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7d0b3d9..8f0bd3f 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1670,6 +1670,7 @@
md->page_order = req_schp->page_order;
md->nr_entries = req_schp->k_use_sg;
md->offset = 0;
+ md->null_mapped = hp->dxferp ? 0 : 1;
}
if (iov_count)
diff --git a/fs/bio.c b/fs/bio.c
index 13be075..062299a 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -859,7 +859,7 @@
/*
* success
*/
- if (!write_to_vm) {
+ if (!write_to_vm && (!map_data || !map_data->null_mapped)) {
ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
if (ret)
goto cleanup;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 811e534..044467e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -691,6 +691,7 @@
int page_order;
int nr_entries;
unsigned long offset;
+ int null_mapped;
};
struct req_iterator {