bio_set_flag(bio, BIO_CLONED);
}
-static unsigned int get_contig_folio_len(struct page **pages,
- unsigned int *num_pages, size_t left,
- size_t offset)
-{
- struct folio *folio = page_folio(pages[0]);
- size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, left);
- unsigned int max_pages, i;
- size_t folio_offset, len;
-
- folio_offset = PAGE_SIZE * folio_page_idx(folio, pages[0]) + offset;
- len = min(folio_size(folio) - folio_offset, left);
-
- /*
- * We might COW a single page in the middle of a large folio, so we have
- * to check that all pages belong to the same folio.
- */
- left -= contig_sz;
- max_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
- for (i = 1; i < max_pages; i++) {
- size_t next = min_t(size_t, PAGE_SIZE, left);
-
- if (page_folio(pages[i]) != folio ||
- pages[i] != pages[i - 1] + 1)
- break;
- contig_sz += next;
- left -= next;
- }
-
- *num_pages = i;
- return contig_sz;
-}
-
-#define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *))
-
-/**
- * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio
- * @bio: bio to add pages to
- * @iter: iov iterator describing the region to be mapped
- *
- * Extracts pages from *iter and appends them to @bio's bvec array. The pages
- * will have to be cleaned up in the way indicated by the BIO_PAGE_PINNED flag.
- * For a multi-segment *iter, this function only adds pages from the next
- * non-empty segment of the iov iterator.
- */
-static ssize_t __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
-{
- iov_iter_extraction_t extraction_flags = 0;
- unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
- unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
- struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
- struct page **pages = (struct page **)bv;
- ssize_t size;
- unsigned int i = 0;
- size_t offset, left, len;
-
- /*
- * Move page array up in the allocated memory for the bio vecs as far as
- * possible so that we can start filling biovecs from the beginning
- * without overwriting the temporary page array.
- */
- BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);
- pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);
-
- if (bio->bi_bdev && blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue))
- extraction_flags |= ITER_ALLOW_P2PDMA;
-
- size = iov_iter_extract_pages(iter, &pages,
- BIO_MAX_SIZE - bio->bi_iter.bi_size,
- nr_pages, extraction_flags, &offset);
- if (unlikely(size <= 0))
- return size ? size : -EFAULT;
-
- nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE);
- for (left = size; left > 0; left -= len) {
- unsigned int nr_to_add;
-
- if (bio->bi_vcnt > 0) {
- struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
-
- if (!zone_device_pages_have_same_pgmap(prev->bv_page,
- pages[i]))
- break;
- }
-
- len = get_contig_folio_len(&pages[i], &nr_to_add, left, offset);
- __bio_add_page(bio, pages[i], len, offset);
- i += nr_to_add;
- offset = 0;
- }
-
- iov_iter_revert(iter, left);
- while (i < nr_pages)
- bio_release_page(bio, pages[i++]);
- return size - left;
-}
-
/*
* Aligns the bio size to the len_align_mask, releasing excessive bio vecs that
* __bio_iov_iter_get_pages may have inserted, and reverts the trimmed length
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter,
unsigned len_align_mask)
{
- ssize_t ret;
+ iov_iter_extraction_t flags = 0;
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return -EIO;
if (iov_iter_extract_will_pin(iter))
bio_set_flag(bio, BIO_PAGE_PINNED);
+ if (bio->bi_bdev && blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue))
+ flags |= ITER_ALLOW_P2PDMA;
do {
- ret = __bio_iov_iter_get_pages(bio, iter);
- } while (ret > 0 && iov_iter_count(iter) && !bio_full(bio, 0));
+ ssize_t ret;
+
+ ret = iov_iter_extract_bvecs(iter, bio->bi_io_vec,
+ BIO_MAX_SIZE - bio->bi_iter.bi_size,
+ &bio->bi_vcnt, bio->bi_max_vecs, flags);
+ if (ret <= 0) {
+ if (!bio->bi_vcnt)
+ return ret;
+ break;
+ }
+ bio->bi_iter.bi_size += ret;
+ } while (iov_iter_count(iter) && !bio_full(bio, 0));
- if (bio->bi_vcnt)
- return bio_iov_iter_align_down(bio, iter, len_align_mask);
- return ret;
+ if (is_pci_p2pdma_page(bio->bi_io_vec->bv_page))
+ bio->bi_opf |= REQ_NOMERGE;
+ return bio_iov_iter_align_down(bio, iter, len_align_mask);
}
static void submit_bio_wait_endio(struct bio *bio)
return -EFAULT;
}
EXPORT_SYMBOL_GPL(iov_iter_extract_pages);
+
+static unsigned int get_contig_folio_len(struct page **pages,
+ unsigned int *num_pages, size_t left, size_t offset)
+{
+ struct folio *folio = page_folio(pages[0]);
+ size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, left);
+ unsigned int max_pages, i;
+ size_t folio_offset, len;
+
+ folio_offset = PAGE_SIZE * folio_page_idx(folio, pages[0]) + offset;
+ len = min(folio_size(folio) - folio_offset, left);
+
+ /*
+ * We might COW a single page in the middle of a large folio, so we have
+ * to check that all pages belong to the same folio.
+ */
+ left -= contig_sz;
+ max_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+ for (i = 1; i < max_pages; i++) {
+ size_t next = min_t(size_t, PAGE_SIZE, left);
+
+ if (page_folio(pages[i]) != folio ||
+ pages[i] != pages[i - 1] + 1)
+ break;
+ contig_sz += next;
+ left -= next;
+ }
+
+ *num_pages = i;
+ return contig_sz;
+}
+
+#define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *))
+
+/**
+ * iov_iter_extract_bvecs - Extract bvecs from an iterator
+ * @iter: the iterator to extract from
+ * @bv: bvec return array
+ * @max_size: maximum size to extract from @iter
+ * @nr_vecs: number of vectors in @bv (on in and output)
+ * @max_vecs: maximum vectors in @bv, including those filled before calling
+ * @extraction_flags: flags to qualify request
+ *
+ * Like iov_iter_extract_pages(), but returns physically contiguous ranges
+ * contained in a single folio as a single bvec instead of multiple entries.
+ *
+ * Returns the number of bytes extracted when successful, or a negative errno.
+ * If @nr_vecs was non-zero on entry, the number of successfully extracted bytes
+ * can be 0.
+ */
+ssize_t iov_iter_extract_bvecs(struct iov_iter *iter, struct bio_vec *bv,
+ size_t max_size, unsigned short *nr_vecs,
+ unsigned short max_vecs, iov_iter_extraction_t extraction_flags)
+{
+ unsigned short entries_left = max_vecs - *nr_vecs;
+ unsigned short nr_pages, i = 0;
+ size_t left, offset, len;
+ struct page **pages;
+ ssize_t size;
+
+ /*
+ * Move page array up in the allocated memory for the bio vecs as far as
+ * possible so that we can start filling biovecs from the beginning
+ * without overwriting the temporary page array.
+ */
+ BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);
+ pages = (struct page **)(bv + *nr_vecs) +
+ entries_left * (PAGE_PTRS_PER_BVEC - 1);
+
+ size = iov_iter_extract_pages(iter, &pages, max_size, entries_left,
+ extraction_flags, &offset);
+ if (unlikely(size <= 0))
+ return size ? size : -EFAULT;
+
+ nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE);
+ for (left = size; left > 0; left -= len) {
+ unsigned int nr_to_add;
+
+ if (*nr_vecs > 0 &&
+ !zone_device_pages_have_same_pgmap(bv[*nr_vecs - 1].bv_page,
+ pages[i]))
+ break;
+
+ len = get_contig_folio_len(&pages[i], &nr_to_add, left, offset);
+ bvec_set_page(&bv[*nr_vecs], pages[i], len, offset);
+ i += nr_to_add;
+ (*nr_vecs)++;
+ offset = 0;
+ }
+
+ iov_iter_revert(iter, left);
+ if (iov_iter_extract_will_pin(iter)) {
+ while (i < nr_pages)
+ unpin_user_page(pages[i++]);
+ }
+ return size - left;
+}
+EXPORT_SYMBOL_GPL(iov_iter_extract_bvecs);
projects / thirdparty / linux.git / commitdiff
