On 05/11/24 04:52PM, Christoph Hellwig wrote:
__bio_iov_iter_get_pages currently open codes adding pages to the bio,
which duplicates a lot of code from bio_add_page. Add a lower level
bio_do_add_page helpers that passes down the same_page output argument
so that __bio_iov_iter_get_pages can reuse the code and also check
for the error return from it - while no error should happen due to
how the bvec space is used for the pin_user_space result I'd rather
be safe than sorry and actually check for these impossible errors.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/bio.c | 66 ++++++++++++++++++++++++-----------------------------
1 file changed, 30 insertions(+), 36 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 1f6ac44b4881..bc3bca5f0686 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1063,20 +1063,9 @@ void __bio_add_page(struct bio *bio, struct page *page,
}
EXPORT_SYMBOL_GPL(__bio_add_page);
-/**
- * bio_add_page - attempt to add page(s) to bio
- * @bio: destination bio
- * @page: start page to add
- * @len: vec entry length, may cross pages
- * @offset: vec entry offset relative to @page, may cross pages
- *
- * Attempt to add page(s) to the bio_vec maplist. This will only fail
- * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
- */
-int bio_add_page(struct bio *bio, struct page *page,
- unsigned int len, unsigned int offset)
+static int bio_do_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset, bool *same_page)
As we are passing length within a folio, values will reach near UINT_MAX.
It will be better to make len and offset as size_t, also to add a check like :
if (len > UINT_MAX || offset > UINT_MAX)
return 0;
{
- bool same_page = false;
nit: extra line got added
