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Date: Wed, 25 Jan 2023 21:06:50 +0000 Message-Id: <20230125210657.2335748-2-dhowells@redhat.com> In-Reply-To: <20230125210657.2335748-1-dhowells@redhat.com> References: <20230125210657.2335748-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: owa1hqifs364zsosryrot64u17da6mfe X-Rspamd-Queue-Id: AF9D4C0007 X-HE-Tag: 1674680830-753456 X-HE-Meta: U2FsdGVkX1+QdGCgh56AaLenjbla1R8eNIKEp09loqYLDhVNGnqBS0oI0U5o27MpobiusZs35IvUCuo7M6xzc1SSyGZ+IBQkSjkVKEyur8a4QX84j9r2g1uxvI6xxIGXCz33kLlxGfeyAjmfSniOSBWTM/uaiqFxoFos6XbJfZRAGz+x8U0T8gyl065ylj4O0cMLd0vhWtL5pqHqXvEC6huta/50XIEs4TqxnPCZM+QVPx5lesVZFqwoXx0Gc9T7m6YbsW2JtDyao6PjXDGqsJIpF5scU4ouVGA0QxtN6e1/o9vLaYwQj9NNLryDgTSxJveQWAifzmsDM2/g4YOxOrTAP6tHtivisXmwJnZ2t8ih/S+9TwNgyW4EJWXxaDAhP2LtD9FcvrLJS4846qs0OW8EanNVVBdConbozEkSs8z9/mmSTEvMASLDmgUhYOgUpdTeje94GKeHj2pq9jF5GFMxNSo6q81y+lFmb8fwVFzY2yfNh5Q7kkWEcT+kcdKs5QcW/j/l+jfq1I1tK7hv1fQKpmlxIqqryCDBa8zsn3drwIR+xjxoMSEgxVba2o1DLHaR/Y2BaKryb8i6cpqAVfH0qm/SXwcMhAgVb496XxXb9pGPA6OeQgwY78HyUQ2pY8uILo8KyuAjLAZg53HI65osNQASqgblC3NOIRLEAXJT5iTP9E5JKpVhbY9bGtg7quK8SUNJmDuQpv9cNPRrHVpMggxhcGj5XEsUNYXjhAeLKlawXGUczozTM3X2hrGpPuQ34qRLzb2jROzNolwP6zugGOPZNLwX5P2tu0xTXZtE0/gzg01Q23dkG5tHFOLgGhNZCJXi1scEMyC8UTuyhfOVL6fXoLl0hXIoCkjTSRBLWd2xYdpGutj9ISePzV2RnWkKNDyJmb4jwk8tdGyu82qY0WWb8R9zMoXhfxj2WFe+oaPbesZi0hGVp92SJAFY6NteSLHVNlxm4Ztw05U tW838L3b DtLJr4ni68qDeexNyQj4x8OcpkJyXRmhow+buWRSf3Df5JWPJvwUjcWSUQp6LHX5Rur93gd2UESSxrs80tJYj4U8sfKl2jp+saLNNsdFzRgHQmm8FztwmDzhe0iAr7HbAWNaOhraCv/g4uNAyykzzT99MDTO6kb2QwRMSGtWIMS7S5Pge6jOurFB2wdJjIk2oolwRqm8+jOAgGG1iXZ6dX7mrxxq3oPjYHj8OlIZ/MqMyBQXI6A+QAPdShFXHkdsStDsc0lKuB1TcbbHgeiCvnFd2EWIwcDPDWoUnjBrr9/XLeGUGKLBMmaS573ZUGQ5lJGJNaHBsH4Sua81fXiDzrEk/bRlcYYBOKJjTN7EBMXnREqAkHkIt33mHfVY6FYrdJgEkL66O9zj+KPbHt5fadZP8NYOVXJL+rHGpPjAozuMAGrUAs9qZFOL31oNqYDA++6r+ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Define flags to qualify page extraction to pass into iov_iter_*_pages*() rather than passing in FOLL_* flags. For now only a flag to allow peer-to-peer DMA is supported. Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Logan Gunthorpe cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org --- Notes: ver #9) - Change extract_flags to extraction_flags. ver #7) - Don't use FOLL_* as a parameter, but rather define constants specifically to use with iov_iter_*_pages*(). - Drop the I/O direction constants for now. block/bio.c | 6 +++--- block/blk-map.c | 8 ++++---- include/linux/uio.h | 7 +++++-- lib/iov_iter.c | 14 ++++++++------ 4 files changed, 20 insertions(+), 15 deletions(-) diff --git a/block/bio.c b/block/bio.c index ab59a491a883..683444e6b711 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1249,7 +1249,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 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; - unsigned int gup_flags = 0; + unsigned int extraction_flags = 0; ssize_t size, left; unsigned len, i = 0; size_t offset, trim; @@ -1264,7 +1264,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); if (bio->bi_bdev && blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue)) - gup_flags |= FOLL_PCI_P2PDMA; + extraction_flags |= ITER_ALLOW_P2PDMA; /* * Each segment in the iov is required to be a block size multiple. @@ -1275,7 +1275,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) */ size = iov_iter_get_pages(iter, pages, UINT_MAX - bio->bi_iter.bi_size, - nr_pages, &offset, gup_flags); + nr_pages, &offset, extraction_flags); if (unlikely(size <= 0)) return size ? size : -EFAULT; diff --git a/block/blk-map.c b/block/blk-map.c index 19940c978c73..7db52ad5b2d0 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -267,7 +267,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, { unsigned int max_sectors = queue_max_hw_sectors(rq->q); unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS); - unsigned int gup_flags = 0; + unsigned int extraction_flags = 0; struct bio *bio; int ret; int j; @@ -280,7 +280,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, return -ENOMEM; if (blk_queue_pci_p2pdma(rq->q)) - gup_flags |= FOLL_PCI_P2PDMA; + extraction_flags |= ITER_ALLOW_P2PDMA; while (iov_iter_count(iter)) { struct page **pages, *stack_pages[UIO_FASTIOV]; @@ -291,10 +291,10 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (nr_vecs <= ARRAY_SIZE(stack_pages)) { pages = stack_pages; bytes = iov_iter_get_pages(iter, pages, LONG_MAX, - nr_vecs, &offs, gup_flags); + nr_vecs, &offs, extraction_flags); } else { bytes = iov_iter_get_pages_alloc(iter, &pages, - LONG_MAX, &offs, gup_flags); + LONG_MAX, &offs, extraction_flags); } if (unlikely(bytes <= 0)) { ret = bytes ? bytes : -EFAULT; diff --git a/include/linux/uio.h b/include/linux/uio.h index 9f158238edba..58fda77f6847 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -252,12 +252,12 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray * loff_t start, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start, - unsigned gup_flags); + unsigned extraction_flags); ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start, - unsigned gup_flags); + unsigned extraction_flags); ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); @@ -360,4 +360,7 @@ static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction, }; } +/* Flags for iov_iter_get/extract_pages*() */ +#define ITER_ALLOW_P2PDMA 0x01 /* Allow P2PDMA on the extracted pages */ + #endif diff --git a/lib/iov_iter.c b/lib/iov_iter.c index f9a3ff37ecd1..da7db39075c6 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1432,9 +1432,9 @@ static struct page *first_bvec_segment(const struct iov_iter *i, static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, unsigned int maxpages, size_t *start, - unsigned int gup_flags) + unsigned int extraction_flags) { - unsigned int n; + unsigned int n, gup_flags = 0; if (maxsize > i->count) maxsize = i->count; @@ -1442,6 +1442,8 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, return 0; if (maxsize > MAX_RW_COUNT) maxsize = MAX_RW_COUNT; + if (extraction_flags & ITER_ALLOW_P2PDMA) + gup_flags |= FOLL_PCI_P2PDMA; if (likely(user_backed_iter(i))) { unsigned long addr; @@ -1495,14 +1497,14 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, - size_t *start, unsigned gup_flags) + size_t *start, unsigned extraction_flags) { if (!maxpages) return 0; BUG_ON(!pages); return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, - start, gup_flags); + start, extraction_flags); } EXPORT_SYMBOL_GPL(iov_iter_get_pages); @@ -1515,14 +1517,14 @@ EXPORT_SYMBOL(iov_iter_get_pages2); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, - size_t *start, unsigned gup_flags) + size_t *start, unsigned extraction_flags) { ssize_t len; *pages = NULL; len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start, - gup_flags); + extraction_flags); if (len <= 0) { kvfree(*pages); *pages = NULL;