RE: [PATCH 02/21] block: Add bio_add_folio()

wangjianjian (C)
2021-11-03T01:26:03Z

diff --git a/block/bio.c b/block/bio.c
index 15ab0d6d1c06..0e911c4fb9f2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1033,6 +1033,28 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page);

+/**
+ * bio_add_folio - Attempt to add part of a folio to a bio.
+ * @bio: BIO to add to.
+ * @folio: Folio to add.
+ * @len: How many bytes from the folio to add.
+ * @off: First byte in this folio to add.
+ *
+ * Filesystems that use folios can call this function instead of
+calling
+ * bio_add_page() for each page in the folio. If @off is bigger than
+ * PAGE_SIZE, this function can create a bio_vec that starts in a page
+ * after the bv_page. BIOs do not support folios that are 4GiB or larger.
+ *
+ * Return: Whether the addition was successful.
+ */
+bool bio_add_folio(struct bio *bio, struct folio *folio, size_t len,
+ size_t off)
+{
+ if (len > UINT_MAX || off > UINT_MAX)
+ return 0;
+ return bio_add_page(bio, &folio->page, len, off) > 0; }
+

Newline.