Add partial mappings support to bio_map_user.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
block/ll_rw_blk.c | 5 +++--
fs/bio.c | 11 +++++++----
include/linux/bio.h | 5 +++--
3 files changed, 13 insertions(+), 8 deletions(-)
cb01cdddfbed14cd32941b34fbbad5b92714eec6
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index f9fc07e..65c56b6 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2293,7 +2293,7 @@ int blk_rq_map_user(request_queue_t *q,
*/
uaddr = (unsigned long) ubuf;
if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))
- bio = bio_map_user(q, NULL, uaddr, len, reading);
+ bio = bio_map_user(q, NULL, uaddr, len, reading, 0);
else
bio = bio_copy_user(q, uaddr, len, reading);
@@ -2345,7 +2345,8 @@ int blk_rq_map_user_iov(request_queue_t
/* we don't allow misaligned data like bio_map_user() does. If the
* user is using sg, they're expected to know the alignment constraints
* and respect them accordingly */
- bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ);
+ bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ,
+ 0);
if (IS_ERR(bio))
return PTR_ERR(bio);
diff --git a/fs/bio.c b/fs/bio.c
index 1f3bb50..fd1e419 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -719,19 +719,21 @@ static struct bio *__bio_map_user_iov(re
* @uaddr: start of user address
* @len: length in bytes
* @write_to_vm: bool indicating writing to pages or not
+ * @support_partial: support partial mappings
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len, int write_to_vm)
+ unsigned long uaddr, unsigned int len, int write_to_vm,
+ int support_partial)
{
struct sg_iovec iov;
iov.iov_base = (void __user *)uaddr;
iov.iov_len = len;
- return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm);
+ return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, support_partial);
}
/**
@@ -741,13 +743,14 @@ struct bio *bio_map_user(request_queue_t
* @iov: the iovec.
* @iov_count: number of elements in the iovec
* @write_to_vm: bool indicating writing to pages or not
+ * @support_partial: support partial mappings
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev,
struct sg_iovec *iov, int iov_count,
- int write_to_vm)
+ int write_to_vm, int support_partial)
{
struct bio *bio;
int len = 0, i;
@@ -768,7 +771,7 @@ struct bio *bio_map_user_iov(request_que
for (i = 0; i < iov_count; i++)
len += iov[i].iov_len;
- if (bio->bi_size == len)
+ if (bio->bi_size == len || support_partial)
return bio;
/*
diff --git a/include/linux/bio.h b/include/linux/bio.h
index b60ffe3..fc0906c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -295,12 +295,13 @@ extern int bio_add_page(struct bio *, st
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
extern int bio_get_nr_vecs(struct block_device *);
+extern int __bio_get_nr_vecs(struct request_queue *);
extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
- unsigned long, unsigned int, int);
+ unsigned long, unsigned int, int, int);
struct sg_iovec;
extern struct bio *bio_map_user_iov(struct request_queue *,
struct block_device *,
- struct sg_iovec *, int, int);
+ struct sg_iovec *, int, int, int);
extern void bio_unmap_user(struct bio *);
extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
gfp_t);
--
1.1.3
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