[0/3] block cleanup patches

[0/3] block cleanup patches

[FUJITA Tomonori]

Here's some minor cleanup patches. This can be applied to the
for-2.6.26 branch in the block tree including the sg conversion
patchset.

[PATCH 1/3] bio: convert bio_copy_kern to use bio_copy_user

[FUJITA Tomonori]

bio_copy_kern and bio_copy_user are very similar. This converts
bio_copy_kern to use bio_copy_user.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
---
 fs/bio.c |   54 ++++--------------------------------------------------
 1 files changed, 4 insertions(+), 50 deletions(-)

diff --git a/fs/bio.c b/fs/bio.c
index a2f0726..9d68ddb 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -995,48 +995,13 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
 struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
 			  gfp_t gfp_mask, int reading)
 {
-	unsigned long kaddr = (unsigned long)data;
-	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	unsigned long start = kaddr >> PAGE_SHIFT;
-	const int nr_pages = end - start;
 	struct bio *bio;
 	struct bio_vec *bvec;
-	struct bio_map_data *bmd;
-	int i, ret;
-	struct sg_iovec iov;
-
-	iov.iov_base = data;
-	iov.iov_len = len;
-
-	bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
-	if (!bmd)
-		return ERR_PTR(-ENOMEM);
-
-	ret = -ENOMEM;
-	bio = bio_alloc(gfp_mask, nr_pages);
-	if (!bio)
-		goto out_bmd;
-
-	while (len) {
-		struct page *page;
-		unsigned int bytes = PAGE_SIZE;
-
-		if (bytes > len)
-			bytes = len;
-
-		page = alloc_page(q->bounce_gfp | gfp_mask);
-		if (!page) {
-			ret = -ENOMEM;
-			goto cleanup;
-		}
-
-		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
-			ret = -EINVAL;
-			goto cleanup;
-		}
+	int i;
 
-		len -= bytes;
-	}
+	bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
+	if (IS_ERR(bio))
+		return bio;
 
 	if (!reading) {
 		void *p = data;
@@ -1049,20 +1014,9 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
 		}
 	}
 
-	bio->bi_private = bmd;
 	bio->bi_end_io = bio_copy_kern_endio;
 
-	bio_set_map_data(bmd, bio, &iov, 1, 1);
 	return bio;
-cleanup:
-	bio_for_each_segment(bvec, bio, i)
-		__free_page(bvec->bv_page);
-
-	bio_put(bio);
-out_bmd:
-	bio_free_map_data(bmd);
-
-	return ERR_PTR(ret);
 }
 
 /*
-- 
1.5.5.GIT

[PATCH 2/3] block: add blk_rq_aligned helper function

[FUJITA Tomonori]

This adds blk_rq_aligned helper function to see if alignment and
padding requirement is satisfied for DMA transfer. This also converts
blk_rq_map_kern and __blk_rq_map_user to use the helper function.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
---
 block/blk-map.c        |   12 ++----------
 include/linux/blkdev.h |    7 +++++++
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/block/blk-map.c b/block/blk-map.c
index dad6a29..572140c 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -45,7 +45,6 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
 			     unsigned int len, gfp_t gfp_mask)
 {
 	unsigned long uaddr;
-	unsigned int alignment;
 	struct bio *bio, *orig_bio;
 	int reading, ret;
 
@@ -56,8 +55,7 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
 	 * direct dma. else, set up kernel bounce buffers
 	 */
 	uaddr = (unsigned long) ubuf;
-	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
-	if (!(uaddr & alignment) && !(len & alignment) && !map_data)
+	if (blk_rq_aligned(q, ubuf, 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);
@@ -274,8 +272,6 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
 int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 		    unsigned int len, gfp_t gfp_mask)
 {
-	unsigned long kaddr;
-	unsigned int alignment;
 	int reading = rq_data_dir(rq) == READ;
 	int do_copy = 0;
 	struct bio *bio;
@@ -285,11 +281,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (!len || !kbuf)
 		return -EINVAL;
 
-	kaddr = (unsigned long)kbuf;
-	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
-	do_copy = ((kaddr & alignment) || (len & alignment) ||
-		   object_is_on_stack(kbuf));
-
+	do_copy = !blk_rq_aligned(q, kbuf, len) || object_is_on_stack(kbuf);
 	if (do_copy)
 		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
 	else
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d2faa72..4cd8caa 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -901,6 +901,13 @@ static inline int queue_dma_alignment(struct request_queue *q)
 	return q ? q->dma_alignment : 511;
 }
 
+static inline int blk_rq_aligned(struct request_queue *q, void *addr,
+				 unsigned int len)
+{
+	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+	return !((unsigned long)addr & alignment) && !(len & alignment);
+}
+
 /* assumes size > 256 */
 static inline unsigned int blksize_bits(unsigned int size)
 {
-- 
1.5.5.GIT

[PATCH 3/3] sg: use blk_rq_aligned helper function

[FUJITA Tomonori]

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Douglas Gilbert <dougg@torque.net>
Cc: Jens Axboe <jens.axboe@oracle.com>
---
 drivers/scsi/sg.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 56a5d96..61262bd 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1656,11 +1656,9 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
 	sg_io_hdr_t *hp = &srp->header;
 	int dxfer_len = (int) hp->dxfer_len;
 	int dxfer_dir = hp->dxfer_direction;
-	unsigned long uaddr = (unsigned long)hp->dxferp;
 	Sg_scatter_hold *req_schp = &srp->data;
 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
 	struct request_queue *q = sfp->parentdp->device->request_queue;
-	unsigned long alignment = queue_dma_alignment(q) | q->dma_pad_mask;
 	struct rq_map_data map_data;
 
 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
@@ -1676,7 +1674,7 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
 	    (!sfp->parentdp->device->host->unchecked_isa_dma) &&
-	    !(uaddr & alignment) && !(dxfer_len & alignment))
+	    blk_rq_aligned(q, hp->dxferp, dxfer_len))
 		return sg_build_direct(srp, sfp, dxfer_len);
 #endif
 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
-- 
1.5.5.GIT

Re: [0/3] block cleanup patches

[Jens Axboe]

On Thu, Aug 28 2008, FUJITA Tomonori wrote:
> Here's some minor cleanup patches. This can be applied to the
> for-2.6.26 branch in the block tree including the sg conversion
> patchset.

Very nice, thanks! Applied to for-2.6.28.

-- 
Jens Axboe