1 files changed, 70 insertions, 5 deletions

diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 68b45c82c37a..5bb6b8aff232 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -11,6 +11,7 @@
 #include <linux/kmemleak.h>
 #include <linux/bvec.h>
 #include <linux/uio.h>
+#include <linux/folio_queue.h>
 
 /**
  * sg_next - return the next scatterlist entry in a list
@@ -473,14 +474,14 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append,
 		return -EOPNOTSUPP;
 
 	if (sgt_append->prv) {
-		unsigned long next_pfn = (page_to_phys(sg_page(sgt_append->prv)) +
-			sgt_append->prv->offset + sgt_append->prv->length) / PAGE_SIZE;
+		unsigned long next_pfn;
 
 		if (WARN_ON(offset))
 			return -EINVAL;
 
 		/* Merge contiguous pages into the last SG */
 		prv_len = sgt_append->prv->length;
+		next_pfn = (sg_phys(sgt_append->prv) + prv_len) / PAGE_SIZE;
 		if (page_to_pfn(pages[0]) == next_pfn) {
 			last_pg = pfn_to_page(next_pfn - 1);
 			while (n_pages && pages_are_mergeable(pages[0], last_pg)) {
@@ -1124,7 +1125,7 @@ static ssize_t extract_user_to_sg(struct iov_iter *iter,
 	do {
 		res = iov_iter_extract_pages(iter, &pages, maxsize, sg_max,
 					     extraction_flags, &off);
-		if (res < 0)
+		if (res <= 0)
 			goto failed;
 
 		len = res;
@@ -1262,6 +1263,67 @@ static ssize_t extract_kvec_to_sg(struct iov_iter *iter,
 }
 
 /*
+ * Extract up to sg_max folios from an FOLIOQ-type iterator and add them to
+ * the scatterlist.  The pages are not pinned.
+ */
+static ssize_t extract_folioq_to_sg(struct iov_iter *iter,
+				   ssize_t maxsize,
+				   struct sg_table *sgtable,
+				   unsigned int sg_max,
+				   iov_iter_extraction_t extraction_flags)
+{
+	const struct folio_queue *folioq = iter->folioq;
+	struct scatterlist *sg = sgtable->sgl + sgtable->nents;
+	unsigned int slot = iter->folioq_slot;
+	ssize_t ret = 0;
+	size_t offset = iter->iov_offset;
+
+	BUG_ON(!folioq);
+
+	if (slot >= folioq_nr_slots(folioq)) {
+		folioq = folioq->next;
+		if (WARN_ON_ONCE(!folioq))
+			return 0;
+		slot = 0;
+	}
+
+	do {
+		struct folio *folio = folioq_folio(folioq, slot);
+		size_t fsize = folioq_folio_size(folioq, slot);
+
+		if (offset < fsize) {
+			size_t part = umin(maxsize - ret, fsize - offset);
+
+			sg_set_page(sg, folio_page(folio, 0), part, offset);
+			sgtable->nents++;
+			sg++;
+			sg_max--;
+			offset += part;
+			ret += part;
+		}
+
+		if (offset >= fsize) {
+			offset = 0;
+			slot++;
+			if (slot >= folioq_nr_slots(folioq)) {
+				if (!folioq->next) {
+					WARN_ON_ONCE(ret < iter->count);
+					break;
+				}
+				folioq = folioq->next;
+				slot = 0;
+			}
+		}
+	} while (sg_max > 0 && ret < maxsize);
+
+	iter->folioq = folioq;
+	iter->folioq_slot = slot;
+	iter->iov_offset = offset;
+	iter->count -= ret;
+	return ret;
+}
+
+/*
  * Extract up to sg_max folios from an XARRAY-type iterator and add them to
  * the scatterlist.  The pages are not pinned.
  */
@@ -1323,8 +1385,8 @@ static ssize_t extract_xarray_to_sg(struct iov_iter *iter,
  * addition of @sg_max elements.
  *
  * The pages referred to by UBUF- and IOVEC-type iterators are extracted and
- * pinned; BVEC-, KVEC- and XARRAY-type are extracted but aren't pinned; PIPE-
- * and DISCARD-type are not supported.
+ * pinned; BVEC-, KVEC-, FOLIOQ- and XARRAY-type are extracted but aren't
+ * pinned; DISCARD-type is not supported.
  *
  * No end mark is placed on the scatterlist; that's left to the caller.
  *
@@ -1356,6 +1418,9 @@ ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t maxsize,
 	case ITER_KVEC:
 		return extract_kvec_to_sg(iter, maxsize, sgtable, sg_max,
 					  extraction_flags);
+	case ITER_FOLIOQ:
+		return extract_folioq_to_sg(iter, maxsize, sgtable, sg_max,
+					    extraction_flags);
 	case ITER_XARRAY:
 		return extract_xarray_to_sg(iter, maxsize, sgtable, sg_max,
 					    extraction_flags);