diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-12 13:43:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-12 13:43:42 -0700 |
| commit | dbc2fba3fc46084f502aec53183995a632998dcd (patch) | |
| tree | a4ee9c95d40c807a133a1542d082f773661869f4 | |
| parent | 5f739e4a491ab63730ef3b7464171340c689fbff (diff) | |
| parent | 6daef95b8c914866a46247232a048447fff97279 (diff) | |
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
"A couple of iov_iter patches - Christoph's crapectomy (the last
remaining user of iov_for_each() went away with lustre, IIRC) and
Eric'c optimization of sanity checks"
* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
iov_iter: optimize page_copy_sane()
uio: remove the unused iov_for_each macro
| -rw-r--r-- | .clang-format | 1 | ||||
| -rw-r--r-- | include/linux/uio.h | 8 | ||||
| -rw-r--r-- | lib/iov_iter.c | 17 |
3 files changed, 15 insertions, 11 deletions
diff --git a/.clang-format b/.clang-format index 201a4f531b90..f49620f506f1 100644 --- a/.clang-format +++ b/.clang-format @@ -290,7 +290,6 @@ ForEachMacros: - 'idr_for_each_entry_ul' - 'inet_bind_bucket_for_each' - 'inet_lhash2_for_each_icsk_rcu' - - 'iov_for_each' - 'key_for_each' - 'key_for_each_safe' - 'klp_for_each_func' diff --git a/include/linux/uio.h b/include/linux/uio.h index ecf584f6b82d..87477e1640f9 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -110,14 +110,6 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) }; } -#define iov_for_each(iov, iter, start) \ - if (iov_iter_type(start) == ITER_IOVEC || \ - iov_iter_type(start) == ITER_KVEC) \ - for (iter = (start); \ - (iter).count && \ - ((iov = iov_iter_iovec(&(iter))), 1); \ - iov_iter_advance(&(iter), (iov).iov_len)) - size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes); void iov_iter_advance(struct iov_iter *i, size_t bytes); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index be4bd627caf0..ea36dc355da1 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -861,8 +861,21 @@ EXPORT_SYMBOL(_copy_from_iter_full_nocache); static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) { - struct page *head = compound_head(page); - size_t v = n + offset + page_address(page) - page_address(head); + struct page *head; + size_t v = n + offset; + + /* + * The general case needs to access the page order in order + * to compute the page size. + * However, we mostly deal with order-0 pages and thus can + * avoid a possible cache line miss for requests that fit all + * page orders. + */ + if (n <= v && v <= PAGE_SIZE) + return true; + + head = compound_head(page); + v += (page - head) << PAGE_SHIFT; if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) return true; |