From 492c5d455969fc2e829f26ed4c83487b068f0dd7 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 30 Nov 2023 13:53:06 -0800 Subject: block: bio-integrity: directly map user buffers Passthrough commands that utilize metadata currently need to bounce the user space buffer through the kernel. Add support for mapping user space directly so that we can avoid this costly overhead. This is similar to how the normal bio data payload utilizes user addresses with bio_map_user_iov(). If the user address can't directly be used for reason, like too many segments or address unalignement, fallback to a copy of the user vec while keeping the user address pinned for the IO duration so that it can safely be copied on completion in any process context. Signed-off-by: Keith Busch Link: https://lore.kernel.org/r/20231130215309.2923568-2-kbusch@meta.com [axboe: fold in fix from Kanchan Joshi] Signed-off-by: Jens Axboe --- include/linux/bio.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index 41d417ee1349..ec4db73e5f4e 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -324,6 +324,8 @@ enum bip_flags { BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */ BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */ BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */ + BIP_INTEGRITY_USER = 1 << 5, /* Integrity payload is user address */ + BIP_COPY_USER = 1 << 6, /* Kernel bounce buffer in use */ }; /* @@ -718,6 +720,7 @@ static inline bool bioset_initialized(struct bio_set *bs) for_each_bio(_bio) \ bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) +int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t len, u32 seed); extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int); extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int); extern bool bio_integrity_prep(struct bio *); @@ -789,6 +792,12 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page, return 0; } +static inline int bio_integrity_map_user(struct bio *bio, void __user *ubuf, + ssize_t len, u32 seed) +{ + return -EINVAL; +} + #endif /* CONFIG_BLK_DEV_INTEGRITY */ /* -- cgit v1.2.3 From 7bed6f3d08b7af27b7015da8dc3acf2b9c1f21d7 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 16 Jan 2024 21:29:59 +0000 Subject: block: Fix iterating over an empty bio with bio_for_each_folio_all If the bio contains no data, bio_first_folio() calls page_folio() on a NULL pointer and oopses. Move the test that we've reached the end of the bio from bio_next_folio() to bio_first_folio(). Reported-by: syzbot+8b23309d5788a79d3eea@syzkaller.appspotmail.com Reported-by: syzbot+004c1e0fced2b4bc3dcc@syzkaller.appspotmail.com Fixes: 640d1930bef4 ("block: Add bio_for_each_folio_all()") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20240116212959.3413014-1-willy@infradead.org [axboe: add unlikely() to error case] Signed-off-by: Jens Axboe --- include/linux/bio.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index ec4db73e5f4e..875d792bffff 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -286,6 +286,11 @@ static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio, { struct bio_vec *bvec = bio_first_bvec_all(bio) + i; + if (unlikely(i >= bio->bi_vcnt)) { + fi->folio = NULL; + return; + } + fi->folio = page_folio(bvec->bv_page); fi->offset = bvec->bv_offset + PAGE_SIZE * (bvec->bv_page - &fi->folio->page); @@ -303,10 +308,8 @@ static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio) fi->offset = 0; fi->length = min(folio_size(fi->folio), fi->_seg_count); fi->_next = folio_next(fi->folio); - } else if (fi->_i + 1 < bio->bi_vcnt) { - bio_first_folio(fi, bio, fi->_i + 1); } else { - fi->folio = NULL; + bio_first_folio(fi, bio, fi->_i + 1); } } -- cgit v1.2.3