block: use blk_rq_map_user_iov to implement blk_rq_map_user

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

2 files changed, 14 insertions, 176 deletions

diff --git a/block/bio.c b/block/bio.c
index 54da51ed43de..879921e6b049 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 f890d4345b0c..152a5fe5d85e 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