diff options
| -rw-r--r-- | include/linux/uio.h | 2 | ||||
| -rw-r--r-- | mm/iov_iter.c | 89 |
2 files changed, 91 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h index 6e16945ec832..28ed2d904deb 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -124,6 +124,8 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) { i->count = count; } +size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); +size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len); int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len); diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 1618e378277e..1d2cdeb57c58 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -3,6 +3,7 @@ #include <linux/pagemap.h> #include <linux/slab.h> #include <linux/vmalloc.h> +#include <net/checksum.h> #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ size_t left; \ @@ -586,6 +587,94 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, } EXPORT_SYMBOL(iov_iter_get_pages_alloc); +size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, + struct iov_iter *i) +{ + char *to = addr; + __wsum sum, next; + size_t off = 0; + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + sum = *csum; + iterate_and_advance(i, bytes, v, ({ + int err = 0; + next = csum_and_copy_from_user(v.iov_base, + (to += v.iov_len) - v.iov_len, + v.iov_len, 0, &err); + if (!err) { + sum = csum_block_add(sum, next, off); + off += v.iov_len; + } + err ? v.iov_len : 0; + }), ({ + char *p = kmap_atomic(v.bv_page); + next = csum_partial_copy_nocheck(p + v.bv_offset, + (to += v.bv_len) - v.bv_len, + v.bv_len, 0); + kunmap_atomic(p); + sum = csum_block_add(sum, next, off); + off += v.bv_len; + }),({ + next = csum_partial_copy_nocheck(v.iov_base, + (to += v.iov_len) - v.iov_len, + v.iov_len, 0); + sum = csum_block_add(sum, next, off); + off += v.iov_len; + }) + ) + *csum = sum; + return bytes; +} +EXPORT_SYMBOL(csum_and_copy_from_iter); + +size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, + struct iov_iter *i) +{ + char *from = addr; + __wsum sum, next; + size_t off = 0; + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + sum = *csum; + iterate_and_advance(i, bytes, v, ({ + int err = 0; + next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, + v.iov_base, + v.iov_len, 0, &err); + if (!err) { + sum = csum_block_add(sum, next, off); + off += v.iov_len; + } + err ? v.iov_len : 0; + }), ({ + char *p = kmap_atomic(v.bv_page); + next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, + p + v.bv_offset, + v.bv_len, 0); + kunmap_atomic(p); + sum = csum_block_add(sum, next, off); + off += v.bv_len; + }),({ + next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, + v.iov_base, + v.iov_len, 0); + sum = csum_block_add(sum, next, off); + off += v.iov_len; + }) + ) + *csum = sum; + return bytes; +} +EXPORT_SYMBOL(csum_and_copy_to_iter); + int iov_iter_npages(const struct iov_iter *i, int maxpages) { size_t size = i->count; |