From: Kent Overstreet <k...@daterainc.com>

Make use of a new interface provided by iov_iter, backed by
scatter-gather list of iovec, instead of the old interface based on
sg_iovec. Also use iov_iter_advance() instead of manual iteration.

This commit should contain only literal replacements, without
functional changes.

Signed-off-by: Kent Overstreet <k...@daterainc.com>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <dongsu.p...@profitbricks.com>
Cc: Jens Axboe <ax...@kernel.dk>
Cc: Doug Gilbert <dgilb...@interlog.com>
Cc: "James E.J. Bottomley" <jbottom...@parallels.com>
---
 block/bio.c            | 114 +++++++++++++++++++++++++------------------------
 block/blk-map.c        |  27 ++++++------
 block/scsi_ioctl.c     |  19 +++------
 drivers/scsi/sg.c      |  15 +++----
 include/linux/bio.h    |   8 ++--
 include/linux/blkdev.h |   4 +-
 6 files changed, 90 insertions(+), 97 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 955bc57..4731c4a 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -997,18 +997,17 @@ void bio_copy_data(struct bio *dst, struct bio *src)
 EXPORT_SYMBOL(bio_copy_data);
 
 struct bio_map_data {
-       int nr_sgvecs;
        int is_our_pages;
-       struct sg_iovec sgvecs[];
+       struct iov_iter iter;
+       struct iovec sgvecs[];
 };
 
 static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
-                            const struct sg_iovec *iov, int iov_count,
-                            int is_our_pages)
+                            const struct iov_iter *iter, int is_our_pages)
 {
-       memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
-       bmd->nr_sgvecs = iov_count;
        bmd->is_our_pages = is_our_pages;
+       bmd->iter = *iter;
+       memcpy(bmd->sgvecs, iter->iov, sizeof(struct iovec) * iter->nr_segs);
        bio->bi_private = bmd;
 }
 
@@ -1022,33 +1021,30 @@ static struct bio_map_data *bio_alloc_map_data(unsigned 
int iov_count,
                       sizeof(struct sg_iovec) * iov_count, gfp_mask);
 }
 
-static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int 
iov_count,
+static int __bio_copy_iov(struct bio *bio, const struct iov_iter *iter,
                          int to_user, int from_user, int do_free_page)
 {
        int ret = 0, i;
        struct bio_vec *bvec;
-       int iov_idx = 0;
-       unsigned int iov_off = 0;
+       struct iov_iter iov_iter = *iter;
 
        bio_for_each_segment_all(bvec, bio, i) {
                char *bv_addr = page_address(bvec->bv_page);
                unsigned int bv_len = bvec->bv_len;
 
-               while (bv_len && iov_idx < iov_count) {
-                       unsigned int bytes;
-                       char __user *iov_addr;
-
-                       bytes = min_t(unsigned int,
-                                     iov[iov_idx].iov_len - iov_off, bv_len);
-                       iov_addr = iov[iov_idx].iov_base + iov_off;
+               while (bv_len && iov_iter.count) {
+                       struct iovec iov = iov_iter_iovec(&iov_iter);
+                       unsigned int bytes = min_t(unsigned int, bv_len,
+                                                  iov.iov_len);
 
                        if (!ret) {
                                if (to_user)
-                                       ret = copy_to_user(iov_addr, bv_addr,
-                                                          bytes);
+                                       ret = copy_to_user(iov.iov_base,
+                                                          bv_addr, bytes);
 
                                if (from_user)
-                                       ret = copy_from_user(bv_addr, iov_addr,
+                                       ret = copy_from_user(bv_addr,
+                                                            iov.iov_base,
                                                             bytes);
 
                                if (ret)
@@ -1057,13 +1053,7 @@ static int __bio_copy_iov(struct bio *bio, const struct 
sg_iovec *iov, int iov_c
 
                        bv_len -= bytes;
                        bv_addr += bytes;
-                       iov_addr += bytes;
-                       iov_off += bytes;
-
-                       if (iov[iov_idx].iov_len == iov_off) {
-                               iov_idx++;
-                               iov_off = 0;
-                       }
+                       iov_iter_advance(&iov_iter, bytes);
                }
 
                if (do_free_page)
@@ -1092,7 +1082,7 @@ int bio_uncopy_user(struct bio *bio)
                 * don't copy into a random user address space, just free.
                 */
                if (current->mm)
-                       ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs,
+                       ret = __bio_copy_iov(bio, &bmd->iter,
                                             bio_data_dir(bio) == READ,
                                             0, bmd->is_our_pages);
                else if (bmd->is_our_pages)
@@ -1120,7 +1110,7 @@ EXPORT_SYMBOL(bio_uncopy_user);
  */
 struct bio *bio_copy_user_iov(struct request_queue *q,
                              struct rq_map_data *map_data,
-                             const struct sg_iovec *iov, int iov_count,
+                             const struct iov_iter *iter,
                              int write_to_vm, gfp_t gfp_mask)
 {
        struct bio_map_data *bmd;
@@ -1129,16 +1119,17 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
        struct bio *bio;
        int i, ret;
        int nr_pages = 0;
-       unsigned int len = 0;
+       unsigned int len;
        unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
 
-       for (i = 0; i < iov_count; i++) {
+       for (i = 0; i < iter->nr_segs; i++) {
                unsigned long uaddr;
                unsigned long end;
                unsigned long start;
 
-               uaddr = (unsigned long)iov[i].iov_base;
-               end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+               uaddr = (unsigned long) iter->iov[i].iov_base;
+               end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
+                       >> PAGE_SHIFT;
                start = uaddr >> PAGE_SHIFT;
 
                /*
@@ -1148,13 +1139,12 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
                        return ERR_PTR(-EINVAL);
 
                nr_pages += end - start;
-               len += iov[i].iov_len;
        }
 
        if (offset)
                nr_pages++;
 
-       bmd = bio_alloc_map_data(iov_count, gfp_mask);
+       bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask);
        if (!bmd)
                return ERR_PTR(-ENOMEM);
 
@@ -1171,7 +1161,12 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
        if (map_data) {
                nr_pages = 1 << map_data->page_order;
                i = map_data->offset / PAGE_SIZE;
+       } else {
+               i = 0;
        }
+
+       len = iter->count;
+
        while (len) {
                unsigned int bytes = PAGE_SIZE;
 
@@ -1213,12 +1208,12 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
         */
        if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||
            (map_data && map_data->from_user)) {
-               ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0);
+               ret = __bio_copy_iov(bio, iter, 0, 1, 0);
                if (ret)
                        goto cleanup;
        }
 
-       bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
+       bio_set_map_data(bmd, bio, iter, map_data ? 0 : 1);
        return bio;
 cleanup:
        if (!map_data)
@@ -1248,30 +1243,35 @@ 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;
+       struct iovec iov;
+       struct iov_iter i;
 
-       iov.iov_base = (void __user *)uaddr;
+       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);
+       iov_iter_init(&i, write_to_vm ? WRITE : READ, &iov, 1, len);
+
+       return bio_copy_user_iov(q, map_data, &i, 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,
+                                     const struct iov_iter *iter,
                                      int write_to_vm, gfp_t gfp_mask)
 {
-       int i, j;
+       int j;
        int nr_pages = 0;
        struct page **pages;
        struct bio *bio;
        int cur_page = 0;
        int ret, offset;
+       struct iov_iter i;
+       struct iovec iov;
 
-       for (i = 0; i < iov_count; i++) {
-               unsigned long uaddr = (unsigned long)iov[i].iov_base;
-               unsigned long len = iov[i].iov_len;
+       iov_for_each(iov, i, *iter) {
+               unsigned long uaddr = (unsigned long) iov.iov_base;
+               unsigned long len = iov.iov_len;
                unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
                unsigned long start = uaddr >> PAGE_SHIFT;
 
@@ -1301,9 +1301,9 @@ static struct bio *__bio_map_user_iov(struct 
request_queue *q,
        if (!pages)
                goto out;
 
-       for (i = 0; i < iov_count; i++) {
-               unsigned long uaddr = (unsigned long)iov[i].iov_base;
-               unsigned long len = iov[i].iov_len;
+       iov_for_each(iov, i, *iter) {
+               unsigned long uaddr = (unsigned long) iov.iov_base;
+               unsigned long len = iov.iov_len;
                unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
                unsigned long start = uaddr >> PAGE_SHIFT;
                const int local_nr_pages = end - start;
@@ -1358,10 +1358,10 @@ static struct bio *__bio_map_user_iov(struct 
request_queue *q,
        return bio;
 
  out_unmap:
-       for (i = 0; i < nr_pages; i++) {
-               if(!pages[i])
+       for (j = 0; j < nr_pages; j++) {
+               if (!pages[j])
                        break;
-               page_cache_release(pages[i]);
+               page_cache_release(pages[j]);
        }
  out:
        kfree(pages);
@@ -1385,12 +1385,15 @@ 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;
+       struct iovec iov;
+       struct iov_iter i;
 
-       iov.iov_base = (void __user *)uaddr;
+       iov.iov_base = (void __user *) uaddr;
        iov.iov_len = len;
 
-       return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
+       iov_iter_init(&i, write_to_vm ? WRITE : READ, &iov, 1, len);
+
+       return bio_map_user_iov(q, bdev, &i, write_to_vm, gfp_mask);
 }
 EXPORT_SYMBOL(bio_map_user);
 
@@ -1407,13 +1410,12 @@ EXPORT_SYMBOL(bio_map_user);
  *     device. Returns an error pointer in case of error.
  */
 struct bio *bio_map_user_iov(struct request_queue *q, struct block_device 
*bdev,
-                            const struct sg_iovec *iov, int iov_count,
+                            const struct iov_iter *iter,
                             int write_to_vm, gfp_t gfp_mask)
 {
        struct bio *bio;
 
-       bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
-                                gfp_mask);
+       bio = __bio_map_user_iov(q, bdev, iter, write_to_vm, gfp_mask);
        if (IS_ERR(bio))
                return bio;
 
diff --git a/block/blk-map.c b/block/blk-map.c
index f890d43..496af28 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -5,7 +5,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
-#include <scsi/sg.h>           /* for struct sg_iovec */
+#include <linux/uio.h>
 
 #include "blk.h"
 
@@ -187,20 +187,22 @@ EXPORT_SYMBOL(blk_rq_map_user);
  *    unmapping.
  */
 int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
-                       struct rq_map_data *map_data, const struct sg_iovec 
*iov,
-                       int iov_count, unsigned int len, gfp_t gfp_mask)
+                       struct rq_map_data *map_data,
+                       const struct iov_iter *iter, gfp_t gfp_mask)
 {
        struct bio *bio;
-       int i, read = rq_data_dir(rq) == READ;
+       int read = rq_data_dir(rq) == READ;
        int unaligned = 0;
+       struct iov_iter i;
+       struct iovec iov;
 
-       if (!iov || iov_count <= 0)
+       if (!iter || !iter->count)
                return -EINVAL;
 
-       for (i = 0; i < iov_count; i++) {
-               unsigned long uaddr = (unsigned long)iov[i].iov_base;
+       iov_for_each(iov, i, *iter) {
+               unsigned long uaddr = (unsigned long) iov.iov_base;
 
-               if (!iov[i].iov_len)
+               if (!iov.iov_len)
                        return -EINVAL;
 
                /*
@@ -210,16 +212,15 @@ int blk_rq_map_user_iov(struct request_queue *q, struct 
request *rq,
                        unaligned = 1;
        }
 
-       if (unaligned || (q->dma_pad_mask & len) || map_data)
-               bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
-                                       gfp_mask);
+       if (unaligned || (q->dma_pad_mask & iter->count) || map_data)
+               bio = bio_copy_user_iov(q, map_data, iter, read, gfp_mask);
        else
-               bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
+               bio = bio_map_user_iov(q, NULL, iter, read, gfp_mask);
 
        if (IS_ERR(bio))
                return PTR_ERR(bio);
 
-       if (bio->bi_iter.bi_size != len) {
+       if (bio->bi_iter.bi_size != iter->count) {
                /*
                 * Grab an extra reference to this bio, as bio_unmap_user()
                 * expects to be able to drop it twice as it happens on the
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 28163fa..8c6652b 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -332,7 +332,7 @@ static int sg_io(struct request_queue *q, struct gendisk 
*bd_disk,
 
        ret = 0;
        if (hdr->iovec_count) {
-               size_t iov_data_len;
+               struct iov_iter i;
                struct iovec *iov = NULL;
 
                ret = rw_copy_check_uvector(-1, hdr->dxferp, hdr->iovec_count,
@@ -342,20 +342,13 @@ static int sg_io(struct request_queue *q, struct gendisk 
*bd_disk,
                        goto out_free_cdb;
                }
 
-               iov_data_len = ret;
-               ret = 0;
-
                /* SG_IO howto says that the shorter of the two wins */
-               if (hdr->dxfer_len < iov_data_len) {
-                       hdr->iovec_count = iov_shorten(iov,
-                                                      hdr->iovec_count,
-                                                      hdr->dxfer_len);
-                       iov_data_len = hdr->dxfer_len;
-               }
+               iov_iter_init(&i,
+                             rq_data_dir(rq) == READ ? WRITE : READ,
+                             iov, hdr->iovec_count,
+                             min_t(unsigned, ret, hdr->dxfer_len));
 
-               ret = blk_rq_map_user_iov(q, rq, NULL, (struct sg_iovec *) iov,
-                                         hdr->iovec_count,
-                                         iov_data_len, GFP_KERNEL);
+               ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
                kfree(iov);
        } else if (hdr->dxfer_len)
                ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index b14f64c..3ce5cad 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1734,22 +1734,19 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
        }
 
        if (iov_count) {
-               int len, size = sizeof(struct sg_iovec) * iov_count;
+               int size = sizeof(struct sg_iovec) * iov_count;
                struct iovec *iov;
+               struct iov_iter i;
 
                iov = memdup_user(hp->dxferp, size);
                if (IS_ERR(iov))
                        return PTR_ERR(iov);
 
-               len = iov_length(iov, iov_count);
-               if (hp->dxfer_len < len) {
-                       iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
-                       len = hp->dxfer_len;
-               }
+               iov_iter_init(&i, rw, iov, iov_count,
+                             min_t(size_t, hp->dxfer_len,
+                                   iov_length(iov, iov_count)));
 
-               res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
-                                         iov_count,
-                                         len, GFP_ATOMIC);
+               res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
                kfree(iov);
        } else
                res = blk_rq_map_user(q, rq, md, hp->dxferp,
diff --git a/include/linux/bio.h b/include/linux/bio.h
index efead0b..a69f7b1 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -430,11 +430,11 @@ extern int bio_add_pc_page(struct request_queue *, struct 
bio *, struct page *,
 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 iov_iter;
 struct rq_map_data;
 extern struct bio *bio_map_user_iov(struct request_queue *,
                                    struct block_device *,
-                                   const struct sg_iovec *, int, int, gfp_t);
+                                   const struct iov_iter *, int, gfp_t);
 extern void bio_unmap_user(struct bio *);
 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
                                gfp_t);
@@ -466,8 +466,8 @@ 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 *,
-                                    int, int, gfp_t);
+                                    const struct iov_iter *,
+                                    int, gfp_t);
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio(struct bio *bio);
 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 191ee4b..c03e37a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -853,8 +853,8 @@ extern int blk_rq_map_user(struct request_queue *, struct 
request *,
 extern int blk_rq_unmap_user(struct bio *);
 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, 
unsigned int, gfp_t);
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
-                              struct rq_map_data *, const struct sg_iovec *,
-                              int, unsigned int, gfp_t);
+                              struct rq_map_data *, const struct iov_iter *,
+                              gfp_t);
 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
                          struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to