From 4b6c132b7da6430cf5dcc96948b04849dea0a32a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 29 Apr 2021 21:16:56 -0400 Subject: iov_iter: switch ..._full() variants of primitives to use of iov_iter_revert() Use corresponding plain variants, revert on short copy. That's the way it should've been done from the very beginning, except that we didn't have iov_iter_revert() back then... [fixed another braino caught by Qian Cai ] Signed-off-by: Al Viro --- include/linux/uio.h | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio.h b/include/linux/uio.h index 74a401f04bd3..68079e2f34eb 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -132,9 +132,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); -bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); -bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i); static __always_inline __must_check size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) @@ -157,10 +155,11 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) static __always_inline __must_check bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) { - if (unlikely(!check_copy_size(addr, bytes, false))) - return false; - else - return _copy_from_iter_full(addr, bytes, i); + size_t copied = copy_from_iter(addr, bytes, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; } static __always_inline __must_check @@ -175,10 +174,11 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) static __always_inline __must_check bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) { - if (unlikely(!check_copy_size(addr, bytes, false))) - return false; - else - return _copy_from_iter_full_nocache(addr, bytes, i); + size_t copied = copy_from_iter_nocache(addr, bytes, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; } #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE @@ -278,7 +278,17 @@ struct csum_state { size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i); size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); -bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); + +static __always_inline __must_check +bool csum_and_copy_from_iter_full(void *addr, size_t bytes, + __wsum *csum, struct iov_iter *i) +{ + size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; +} size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, struct iov_iter *i); -- cgit v1.2.3