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Date: Fri, 16 Jan 2015 13:04:50 +0100
From: Christoph Hellwig <hch@....de>
To: Jens Axboe <axboe@...nel.dk>,
Dongsu Park <dongsu.park@...fitbricks.com>
Cc: Kent Overstreet <kmo@...erainc.com>, linux-kernel@...r.kernel.org
Subject: [PATCH 2/7] block: use blk_rq_map_user_iov to implement blk_rq_map_user
Signed-off-by: Christoph Hellwig <hch@....de>
---
block/bio.c | 53 +-------------------
block/blk-map.c | 137 +++++-----------------------------------------------
include/linux/bio.h | 4 --
3 files changed, 14 insertions(+), 180 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 54da51e..879921e 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1102,7 +1102,7 @@ static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_c
* bio_uncopy_user - finish previously mapped bio
* @bio: bio being terminated
*
- * Free pages allocated from bio_copy_user() and write back data
+ * Free pages allocated from bio_copy_user_iov() and write back data
* to user space in case of a read.
*/
int bio_uncopy_user(struct bio *bio)
@@ -1256,32 +1256,6 @@ out_bmd:
return ERR_PTR(ret);
}
-/**
- * bio_copy_user - copy user data to bio
- * @q: destination block queue
- * @map_data: pointer to the rq_map_data holding pages (if necessary)
- * @uaddr: start of user address
- * @len: length in bytes
- * @write_to_vm: bool indicating writing to pages or not
- * @gfp_mask: memory allocation flags
- *
- * Prepares and returns a bio for indirect user io, bouncing data
- * to/from kernel pages as necessary. Must be paired with
- * call bio_uncopy_user() on io completion.
- */
-struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
- unsigned long uaddr, unsigned int len,
- int write_to_vm, gfp_t gfp_mask)
-{
- struct sg_iovec iov;
-
- iov.iov_base = (void __user *)uaddr;
- iov.iov_len = len;
-
- return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
-}
-EXPORT_SYMBOL(bio_copy_user);
-
static struct bio *__bio_map_user_iov(struct request_queue *q,
struct block_device *bdev,
const struct sg_iovec *iov, int iov_count,
@@ -1395,31 +1369,6 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
}
/**
- * bio_map_user - map user address into bio
- * @q: the struct request_queue for the bio
- * @bdev: destination block device
- * @uaddr: start of user address
- * @len: length in bytes
- * @write_to_vm: bool indicating writing to pages or not
- * @gfp_mask: memory allocation flags
- *
- * 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(struct request_queue *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len, int write_to_vm,
- gfp_t gfp_mask)
-{
- 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, gfp_mask);
-}
-EXPORT_SYMBOL(bio_map_user);
-
-/**
* bio_map_user_iov - map user sg_iovec table into bio
* @q: the struct request_queue for the bio
* @bdev: destination block device
diff --git a/block/blk-map.c b/block/blk-map.c
index f890d43..152a5fe 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -39,130 +39,6 @@ static int __blk_rq_unmap_user(struct bio *bio)
return ret;
}
-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, gfp_t gfp_mask)
-{
- unsigned long uaddr;
- struct bio *bio, *orig_bio;
- int reading, ret;
-
- reading = rq_data_dir(rq) == READ;
-
- /*
- * if alignment requirement is satisfied, map in user pages for
- * direct dma. else, set up kernel bounce buffers
- */
- uaddr = (unsigned long) ubuf;
- if (blk_rq_aligned(q, uaddr, len) && !map_data)
- bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
- else
- bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);
-
- if (IS_ERR(bio))
- return PTR_ERR(bio);
-
- if (map_data && map_data->null_mapped)
- bio->bi_flags |= (1 << BIO_NULL_MAPPED);
-
- orig_bio = bio;
- blk_queue_bounce(q, &bio);
-
- /*
- * We link the bounce buffer in and could have to traverse it
- * later so we have to get a ref to prevent it from being freed
- */
- bio_get(bio);
-
- ret = blk_rq_append_bio(q, rq, bio);
- if (!ret)
- return bio->bi_iter.bi_size;
-
- /* if it was boucned we must call the end io function */
- bio_endio(bio, 0);
- __blk_rq_unmap_user(orig_bio);
- bio_put(bio);
- return ret;
-}
-
-/**
- * blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
- * @q: request queue where request should be inserted
- * @rq: request structure to fill
- * @map_data: pointer to the rq_map_data holding pages (if necessary)
- * @ubuf: the user buffer
- * @len: length of user data
- * @gfp_mask: memory allocation flags
- *
- * Description:
- * Data will be mapped directly for zero copy I/O, if possible. Otherwise
- * a kernel bounce buffer is used.
- *
- * A matching blk_rq_unmap_user() must be issued at the end of I/O, while
- * still in process context.
- *
- * Note: The mapped bio may need to be bounced through blk_queue_bounce()
- * before being submitted to the device, as pages mapped may be out of
- * reach. It's the callers responsibility to make sure this happens. The
- * original bio must be passed back in to blk_rq_unmap_user() for proper
- * unmapping.
- */
-int blk_rq_map_user(struct request_queue *q, struct request *rq,
- struct rq_map_data *map_data, void __user *ubuf,
- unsigned long len, gfp_t gfp_mask)
-{
- unsigned long bytes_read = 0;
- struct bio *bio = NULL;
- int ret;
-
- if (len > (queue_max_hw_sectors(q) << 9))
- return -EINVAL;
- if (!len)
- return -EINVAL;
-
- if (!ubuf && (!map_data || !map_data->null_mapped))
- return -EINVAL;
-
- while (bytes_read != len) {
- unsigned long map_len, end, start;
-
- map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
- end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
- >> PAGE_SHIFT;
- start = (unsigned long)ubuf >> PAGE_SHIFT;
-
- /*
- * A bad offset could cause us to require BIO_MAX_PAGES + 1
- * pages. If this happens we just lower the requested
- * mapping len by a page so that we can fit
- */
- if (end - start > BIO_MAX_PAGES)
- map_len -= PAGE_SIZE;
-
- ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
- gfp_mask);
- if (ret < 0)
- goto unmap_rq;
- if (!bio)
- bio = rq->bio;
- bytes_read += ret;
- ubuf += ret;
-
- if (map_data)
- map_data->offset += ret;
- }
-
- if (!bio_flagged(bio, BIO_USER_MAPPED))
- rq->cmd_flags |= REQ_COPY_USER;
-
- return 0;
-unmap_rq:
- blk_rq_unmap_user(bio);
- rq->bio = NULL;
- return ret;
-}
-EXPORT_SYMBOL(blk_rq_map_user);
-
/**
* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
* @q: request queue where request should be inserted
@@ -241,6 +117,19 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_rq_map_user_iov);
+int blk_rq_map_user(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data, void __user *ubuf,
+ unsigned long len, gfp_t gfp_mask)
+{
+ struct sg_iovec iov;
+
+ iov.iov_base = (void __user *)ubuf;
+ iov.iov_len = len;
+
+ return blk_rq_map_user_iov(q, rq, map_data, &iov, 1, len, gfp_mask);
+}
+EXPORT_SYMBOL(blk_rq_map_user);
+
/**
* blk_rq_unmap_user - unmap a request with user data
* @bio: start of bio list
diff --git a/include/linux/bio.h b/include/linux/bio.h
index efead0b..d0d6735 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -428,8 +428,6 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
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 struct bio *bio_map_user(struct request_queue *, struct block_device *,
- unsigned long, unsigned int, int, gfp_t);
struct sg_iovec;
struct rq_map_data;
extern struct bio *bio_map_user_iov(struct request_queue *,
@@ -462,8 +460,6 @@ static inline void bio_flush_dcache_pages(struct bio *bi)
extern void bio_copy_data(struct bio *dst, struct bio *src);
extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
-extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
- unsigned long, unsigned int, int, gfp_t);
extern struct bio *bio_copy_user_iov(struct request_queue *,
struct rq_map_data *,
const struct sg_iovec *,
--
1.9.1
--
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