diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 69 |
1 files changed, 32 insertions, 37 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 2e452ce7388b..14cae2584db4 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -582,7 +582,7 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes, static __wsum csum_and_memcpy(void *to, const void *from, size_t len, __wsum sum, size_t off) { - __wsum next = csum_partial_copy_nocheck(from, to, len, 0); + __wsum next = csum_partial_copy_nocheck(from, to, len); return csum_block_add(sum, next, off); } @@ -638,30 +638,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) } EXPORT_SYMBOL(_copy_to_iter); -#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE -static int copyout_mcsafe(void __user *to, const void *from, size_t n) +#ifdef CONFIG_ARCH_HAS_COPY_MC +static int copyout_mc(void __user *to, const void *from, size_t n) { if (access_ok(to, n)) { instrument_copy_to_user(to, from, n); - n = copy_to_user_mcsafe((__force void *) to, from, n); + n = copy_mc_to_user((__force void *) to, from, n); } return n; } -static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, +static unsigned long copy_mc_to_page(struct page *page, size_t offset, const char *from, size_t len) { unsigned long ret; char *to; to = kmap_atomic(page); - ret = memcpy_mcsafe(to + offset, from, len); + ret = copy_mc_to_kernel(to + offset, from, len); kunmap_atomic(to); return ret; } -static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, +static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, struct iov_iter *i) { struct pipe_inode_info *pipe = i->pipe; @@ -679,7 +679,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, size_t chunk = min_t(size_t, n, PAGE_SIZE - off); unsigned long rem; - rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, + rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); i->head = i_head; i->iov_offset = off + chunk - rem; @@ -696,18 +696,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, } /** - * _copy_to_iter_mcsafe - copy to user with source-read error exception handling + * _copy_mc_to_iter - copy to iter with source memory error exception handling * @addr: source kernel address * @bytes: total transfer length * @iter: destination iterator * - * The pmem driver arranges for filesystem-dax to use this facility via - * dax_copy_to_iter() for protecting read/write to persistent memory. - * Unless / until an architecture can guarantee identical performance - * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a - * performance regression to switch more users to the mcsafe version. + * The pmem driver deploys this for the dax operation + * (dax_copy_to_iter()) for dax reads (bypass page-cache and the + * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes + * successfully copied. * - * Otherwise, the main differences between this and typical _copy_to_iter(). + * The main differences between this and typical _copy_to_iter(). * * * Typical tail/residue handling after a fault retries the copy * byte-by-byte until the fault happens again. Re-triggering machine @@ -718,23 +717,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. * Compare to copy_to_iter() where only ITER_IOVEC attempts might return * a short copy. - * - * See MCSAFE_TEST for self-test. */ -size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) +size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) { const char *from = addr; unsigned long rem, curr_addr, s_addr = (unsigned long) addr; if (unlikely(iov_iter_is_pipe(i))) - return copy_pipe_to_iter_mcsafe(addr, bytes, i); + return copy_mc_pipe_to_iter(addr, bytes, i); if (iter_is_iovec(i)) might_fault(); iterate_and_advance(i, bytes, v, - copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), + copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, + v.iov_len), ({ - rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, - (from += v.bv_len) - v.bv_len, v.bv_len); + rem = copy_mc_to_page(v.bv_page, v.bv_offset, + (from += v.bv_len) - v.bv_len, v.bv_len); if (rem) { curr_addr = (unsigned long) from; bytes = curr_addr - s_addr - rem; @@ -742,8 +740,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) } }), ({ - rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, - v.iov_len); + rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) + - v.iov_len, v.iov_len); if (rem) { curr_addr = (unsigned long) from; bytes = curr_addr - s_addr - rem; @@ -754,8 +752,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) return bytes; } -EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); -#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ +EXPORT_SYMBOL_GPL(_copy_mc_to_iter); +#endif /* CONFIG_ARCH_HAS_COPY_MC */ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) { @@ -1450,15 +1448,14 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, return 0; } 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) { + v.iov_len); + if (next) { sum = csum_block_add(sum, next, off); off += v.iov_len; } - err ? v.iov_len : 0; + next ? 0 : v.iov_len; }), ({ char *p = kmap_atomic(v.bv_page); sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, @@ -1492,11 +1489,10 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, if (unlikely(i->count < bytes)) return false; iterate_all_kinds(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) + v.iov_len); + if (!next) return false; sum = csum_block_add(sum, next, off); off += v.iov_len; @@ -1538,15 +1534,14 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, return 0; } 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) { + v.iov_len); + if (next) { sum = csum_block_add(sum, next, off); off += v.iov_len; } - err ? v.iov_len : 0; + next ? 0 : v.iov_len; }), ({ char *p = kmap_atomic(v.bv_page); sum = csum_and_memcpy(p + v.bv_offset, |