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| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-30 16:26:41 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-10 17:45:14 +0200 |
| commit | f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454 (patch) | |
| tree | 05ad20f84ee097a534132fa9b2df9feae6d4a7d2 /lib | |
| parent | [xarray] iov_iter_npages(): just use DIV_ROUND_UP() (diff) | |
| download | linux-f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454.tar.xz linux-f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454.zip | |
iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the
callers do *not* need to do iov_iter_advance() after it. In case when they end
up consuming less than they'd been given they need to do iov_iter_revert() on
everything they had not consumed. That, however, needs to be done only on slow
paths.
All in-tree callers converted. And that kills the last user of iterate_all_kinds()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/iov_iter.c | 30 |
1 files changed, 4 insertions, 26 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 72c5bb794e8d..362e8b5a5dc5 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -114,28 +114,6 @@ n = wanted - n; \ } -#define iterate_all_kinds(i, n, v, I, B, K, X) { \ - if (likely(n)) { \ - size_t skip = i->iov_offset; \ - if (likely(iter_is_iovec(i))) { \ - const struct iovec *iov; \ - struct iovec v; \ - iterate_iovec(i, n, v, iov, skip, (I)) \ - } else if (iov_iter_is_bvec(i)) { \ - struct bio_vec v; \ - struct bvec_iter __bi; \ - iterate_bvec(i, n, v, __bi, skip, (B)) \ - } else if (iov_iter_is_kvec(i)) { \ - const struct kvec *kvec; \ - struct kvec v; \ - iterate_kvec(i, n, v, kvec, skip, (K)) \ - } else if (iov_iter_is_xarray(i)) { \ - struct bio_vec v; \ - iterate_xarray(i, n, v, skip, (X)); \ - } \ - } \ -} - #define iterate_and_advance(i, n, v, I, B, K, X) { \ if (unlikely(i->count < n)) \ n = i->count; \ @@ -1009,8 +987,8 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i) } EXPORT_SYMBOL(iov_iter_zero); -size_t iov_iter_copy_from_user_atomic(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) +size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, + struct iov_iter *i) { char *kaddr = kmap_atomic(page), *p = kaddr + offset; if (unlikely(!page_copy_sane(page, offset, bytes))) { @@ -1022,7 +1000,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, WARN_ON(1); return 0; } - iterate_all_kinds(i, bytes, v, + iterate_and_advance(i, bytes, v, copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, v.bv_offset, v.bv_len), @@ -1033,7 +1011,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, kunmap_atomic(kaddr); return bytes; } -EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); +EXPORT_SYMBOL(copy_page_from_iter_atomic); static inline void pipe_truncate(struct iov_iter *i) { |