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-rw-r--r--block/bio.c192
1 files changed, 73 insertions, 119 deletions
diff --git a/block/bio.c b/block/bio.c
index 459cc857f3d9..228229f3bb76 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1062,14 +1062,21 @@ struct bio_map_data {
struct iovec iov[];
};
-static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,
+static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
gfp_t gfp_mask)
{
- if (iov_count > UIO_MAXIOV)
+ struct bio_map_data *bmd;
+ if (data->nr_segs > UIO_MAXIOV)
return NULL;
- return kmalloc(sizeof(struct bio_map_data) +
- sizeof(struct iovec) * iov_count, gfp_mask);
+ bmd = kmalloc(sizeof(struct bio_map_data) +
+ sizeof(struct iovec) * data->nr_segs, gfp_mask);
+ if (!bmd)
+ return NULL;
+ memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
+ bmd->iter = *data;
+ bmd->iter.iov = bmd->iov;
+ return bmd;
}
/**
@@ -1080,7 +1087,7 @@ static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,
* Copy all pages from iov_iter to bio.
* Returns 0 on success, or error on failure.
*/
-static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter)
+static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
{
int i;
struct bio_vec *bvec;
@@ -1091,9 +1098,9 @@ static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter)
ret = copy_page_from_iter(bvec->bv_page,
bvec->bv_offset,
bvec->bv_len,
- &iter);
+ iter);
- if (!iov_iter_count(&iter))
+ if (!iov_iter_count(iter))
break;
if (ret < bvec->bv_len)
@@ -1187,40 +1194,18 @@ int bio_uncopy_user(struct bio *bio)
*/
struct bio *bio_copy_user_iov(struct request_queue *q,
struct rq_map_data *map_data,
- const struct iov_iter *iter,
+ struct iov_iter *iter,
gfp_t gfp_mask)
{
struct bio_map_data *bmd;
struct page *page;
struct bio *bio;
- int i, ret;
- int nr_pages = 0;
+ int i = 0, ret;
+ int nr_pages;
unsigned int len = iter->count;
unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
- for (i = 0; i < iter->nr_segs; i++) {
- unsigned long uaddr;
- unsigned long end;
- unsigned long start;
-
- uaddr = (unsigned long) iter->iov[i].iov_base;
- end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
- >> PAGE_SHIFT;
- start = uaddr >> PAGE_SHIFT;
-
- /*
- * Overflow, abort
- */
- if (end < start)
- return ERR_PTR(-EINVAL);
-
- nr_pages += end - start;
- }
-
- if (offset)
- nr_pages++;
-
- bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask);
+ bmd = bio_alloc_map_data(iter, gfp_mask);
if (!bmd)
return ERR_PTR(-ENOMEM);
@@ -1230,9 +1215,10 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
* shortlived one.
*/
bmd->is_our_pages = map_data ? 0 : 1;
- memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs);
- bmd->iter = *iter;
- bmd->iter.iov = bmd->iov;
+
+ nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+ if (nr_pages > BIO_MAX_PAGES)
+ nr_pages = BIO_MAX_PAGES;
ret = -ENOMEM;
bio = bio_kmalloc(gfp_mask, nr_pages);
@@ -1281,17 +1267,24 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
if (ret)
goto cleanup;
+ if (map_data)
+ map_data->offset += bio->bi_iter.bi_size;
+
/*
* success
*/
if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
(map_data && map_data->from_user)) {
- ret = bio_copy_from_iter(bio, *iter);
+ ret = bio_copy_from_iter(bio, iter);
if (ret)
goto cleanup;
+ } else {
+ iov_iter_advance(iter, bio->bi_iter.bi_size);
}
bio->bi_private = bmd;
+ if (map_data && map_data->null_mapped)
+ bio_set_flag(bio, BIO_NULL_MAPPED);
return bio;
cleanup:
if (!map_data)
@@ -1312,111 +1305,74 @@ out_bmd:
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user_iov(struct request_queue *q,
- const struct iov_iter *iter,
+ struct iov_iter *iter,
gfp_t gfp_mask)
{
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;
+ int ret;
struct bio_vec *bvec;
- 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;
-
- /*
- * Overflow, abort
- */
- if (end < start)
- return ERR_PTR(-EINVAL);
-
- nr_pages += end - start;
- /*
- * buffer must be aligned to at least logical block size for now
- */
- if (uaddr & queue_dma_alignment(q))
- return ERR_PTR(-EINVAL);
- }
-
- if (!nr_pages)
+ if (!iov_iter_count(iter))
return ERR_PTR(-EINVAL);
- bio = bio_kmalloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
if (!bio)
return ERR_PTR(-ENOMEM);
- ret = -ENOMEM;
- pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
- if (!pages)
- goto out;
+ while (iov_iter_count(iter)) {
+ struct page **pages;
+ ssize_t bytes;
+ size_t offs, added = 0;
+ int npages;
- 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;
- const int page_limit = cur_page + local_nr_pages;
-
- ret = get_user_pages_fast(uaddr, local_nr_pages,
- (iter->type & WRITE) != WRITE,
- &pages[cur_page]);
- if (unlikely(ret < local_nr_pages)) {
- for (j = cur_page; j < page_limit; j++) {
- if (!pages[j])
- break;
- put_page(pages[j]);
- }
- ret = -EFAULT;
+ bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
+ if (unlikely(bytes <= 0)) {
+ ret = bytes ? bytes : -EFAULT;
goto out_unmap;
}
- offset = offset_in_page(uaddr);
- for (j = cur_page; j < page_limit; j++) {
- unsigned int bytes = PAGE_SIZE - offset;
- unsigned short prev_bi_vcnt = bio->bi_vcnt;
+ npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
- if (len <= 0)
- break;
-
- if (bytes > len)
- bytes = len;
-
- /*
- * sorry...
- */
- if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
- bytes)
- break;
+ if (unlikely(offs & queue_dma_alignment(q))) {
+ ret = -EINVAL;
+ j = 0;
+ } else {
+ for (j = 0; j < npages; j++) {
+ struct page *page = pages[j];
+ unsigned int n = PAGE_SIZE - offs;
+ unsigned short prev_bi_vcnt = bio->bi_vcnt;
- /*
- * check if vector was merged with previous
- * drop page reference if needed
- */
- if (bio->bi_vcnt == prev_bi_vcnt)
- put_page(pages[j]);
+ if (n > bytes)
+ n = bytes;
- len -= bytes;
- offset = 0;
- }
+ if (!bio_add_pc_page(q, bio, page, n, offs))
+ break;
- cur_page = j;
+ /*
+ * check if vector was merged with previous
+ * drop page reference if needed
+ */
+ if (bio->bi_vcnt == prev_bi_vcnt)
+ put_page(page);
+
+ added += n;
+ bytes -= n;
+ offs = 0;
+ }
+ iov_iter_advance(iter, added);
+ }
/*
* release the pages we didn't map into the bio, if any
*/
- while (j < page_limit)
+ while (j < npages)
put_page(pages[j++]);
+ kvfree(pages);
+ /* couldn't stuff something into bio? */
+ if (bytes)
+ break;
}
- kfree(pages);
-
bio_set_flag(bio, BIO_USER_MAPPED);
/*
@@ -1432,8 +1388,6 @@ struct bio *bio_map_user_iov(struct request_queue *q,
bio_for_each_segment_all(bvec, bio, j) {
put_page(bvec->bv_page);
}
- out:
- kfree(pages);
bio_put(bio);
return ERR_PTR(ret);
}