block: introduce struct rq_map_data to use reserved pages

This patch introduces struct rq_map_data to enable bio_copy_use_iov()
use reserved pages.

Currently, bio_copy_user_iov allocates bounce pages but
drivers/scsi/sg.c wants to allocate pages by itself and use
them. struct rq_map_data can be used to pass allocated pages to
bio_copy_user_iov.

The current users of bio_copy_user_iov simply passes NULL (they don't
want to use pre-allocated pages).

Signed-off-by: FUJITA Tomonori <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Douglas Gilbert <[email protected]>
Cc: Mike Christie <[email protected]>
Cc: James Bottomley <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
FUJITA Tomonori 2008-08-28 16:17:06 +09:00 • committed by Jens Axboe
commit 152e283fdf
8 changed files with 80 additions and 39 deletions

View file

@ -283,8 +283,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, int has_write_perm)
next_rq->cmd_type = rq->cmd_type;
dxferp = (void*)(unsigned long)hdr->din_xferp;
ret = blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len,
GFP_KERNEL);
ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
hdr->din_xfer_len, GFP_KERNEL);
if (ret)
goto out;
}
@ -299,7 +299,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, int has_write_perm)
dxfer_len = 0;
if (dxfer_len) {
ret = blk_rq_map_user(q, rq, dxferp, dxfer_len, GFP_KERNEL);
ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
GFP_KERNEL);
if (ret)
goto out;
}