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Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 26/29] iov_iter: Split iov_iter_npages() From: David Howells To: Pavel Begunkov , Matthew Wilcox , Jens Axboe , Alexander Viro Cc: dhowells@redhat.com, Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 21 Nov 2020 14:16:44 +0000 Message-ID: <160596820474.154728.13702168133845850499.stgit@warthog.procyon.org.uk> In-Reply-To: <160596800145.154728.7192318545120181269.stgit@warthog.procyon.org.uk> References: <160596800145.154728.7192318545120181269.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Split iov_iter_npages() by type. Signed-off-by: David Howells --- lib/iov_iter.c | 84 ++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 57 insertions(+), 27 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 2f8019e3b09a..d8ef6c81c55f 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -2004,50 +2004,80 @@ size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, } EXPORT_SYMBOL(hash_and_copy_to_iter); -static int xxx_npages(const struct iov_iter *i, int maxpages) +static int iovec_npages(const struct iov_iter *i, int maxpages) { size_t size = i->count; int npages = 0; if (!size) return 0; - if (unlikely(iov_iter_is_discard(i))) - return 0; - - if (unlikely(iov_iter_is_pipe(i))) { - struct pipe_inode_info *pipe = i->pipe; - unsigned int iter_head; - size_t off; - - if (!sanity(i)) - return 0; - - data_start(i, &iter_head, &off); - /* some of this one + all after this one */ - npages = pipe_space_for_user(iter_head, pipe->tail, pipe); - if (npages >= maxpages) - return maxpages; - } else iterate_all_kinds(i, size, v, ({ + iterate_over_iovec(i, size, v, ({ unsigned long p = (unsigned long)v.iov_base; npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) - p / PAGE_SIZE; if (npages >= maxpages) return maxpages; - 0;}),({ + 0;})); + return npages; +} + +static int bvec_npages(const struct iov_iter *i, int maxpages) +{ + size_t size = i->count; + int npages = 0; + + if (!size) + return 0; + iterate_over_bvec(i, size, v, ({ npages++; if (npages >= maxpages) return maxpages; - }),({ + })); + return npages; +} + +static int kvec_npages(const struct iov_iter *i, int maxpages) +{ + size_t size = i->count; + int npages = 0; + + if (!size) + return 0; + iterate_over_kvec(i, size, v, ({ unsigned long p = (unsigned long)v.iov_base; npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) - p / PAGE_SIZE; if (npages >= maxpages) return maxpages; - }) - ) + })); return npages; } +static int pipe_npages(const struct iov_iter *i, int maxpages) +{ + struct pipe_inode_info *pipe = i->pipe; + size_t size = i->count, off; + unsigned int iter_head; + int npages = 0; + + if (!size) + return 0; + if (!sanity(i)) + return 0; + + data_start(i, &iter_head, &off); + /* some of this one + all after this one */ + npages = pipe_space_for_user(iter_head, pipe->tail, pipe); + if (npages >= maxpages) + return maxpages; + return npages; +} + +static int discard_npages(const struct iov_iter *i, int maxpages) +{ + return 0; +} + static const void *xxx_dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) { *new = *old; @@ -2293,7 +2323,7 @@ static const struct iov_iter_ops iovec_iter_ops = { .gap_alignment = iovec_gap_alignment, .get_pages = iovec_get_pages, .get_pages_alloc = iovec_get_pages_alloc, - .npages = xxx_npages, + .npages = iovec_npages, .dup_iter = xxx_dup_iter, .for_each_range = xxx_for_each_range, }; @@ -2327,7 +2357,7 @@ static const struct iov_iter_ops kvec_iter_ops = { .gap_alignment = kvec_gap_alignment, .get_pages = no_get_pages, .get_pages_alloc = no_get_pages_alloc, - .npages = xxx_npages, + .npages = kvec_npages, .dup_iter = xxx_dup_iter, .for_each_range = xxx_for_each_range, }; @@ -2361,7 +2391,7 @@ static const struct iov_iter_ops bvec_iter_ops = { .gap_alignment = bvec_gap_alignment, .get_pages = bvec_get_pages, .get_pages_alloc = bvec_get_pages_alloc, - .npages = xxx_npages, + .npages = bvec_npages, .dup_iter = xxx_dup_iter, .for_each_range = xxx_for_each_range, }; @@ -2395,7 +2425,7 @@ static const struct iov_iter_ops pipe_iter_ops = { .gap_alignment = no_gap_alignment, .get_pages = pipe_get_pages, .get_pages_alloc = pipe_get_pages_alloc, - .npages = xxx_npages, + .npages = pipe_npages, .dup_iter = xxx_dup_iter, .for_each_range = xxx_for_each_range, }; @@ -2429,7 +2459,7 @@ static const struct iov_iter_ops discard_iter_ops = { .gap_alignment = no_gap_alignment, .get_pages = no_get_pages, .get_pages_alloc = no_get_pages_alloc, - .npages = xxx_npages, + .npages = discard_npages, .dup_iter = xxx_dup_iter, .for_each_range = xxx_for_each_range, };