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author | Al Viro <viro@zeniv.linux.org.uk> | 2014-11-27 14:18:54 -0500 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-11-27 18:44:12 -0500 |
commit | 8442fa46cf244cd65401f1a5bb830ed420fc1e54 (patch) | |
tree | 15e36811668838fa6573c630587a98daceb4e80d /mm/iov_iter.c | |
parent | 1b17f1f2e56a091deb99a068a6f1e82b5bb76b09 (diff) | |
download | linux-stable-8442fa46cf244cd65401f1a5bb830ed420fc1e54.tar.gz linux-stable-8442fa46cf244cd65401f1a5bb830ed420fc1e54.tar.bz2 linux-stable-8442fa46cf244cd65401f1a5bb830ed420fc1e54.zip |
iov_iter.c: convert iov_iter_zero() to iterate_and_advance
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/iov_iter.c')
-rw-r--r-- | mm/iov_iter.c | 98 |
1 files changed, 12 insertions, 86 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 3214b9b493ae..39ad7137f739 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -349,50 +349,6 @@ done: return wanted - bytes; } -static size_t zero_iovec(size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - left = __clear_user(buf, copy); - copy -= left; - skip += copy; - bytes -= copy; - - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __clear_user(buf, copy); - copy -= left; - skip = copy; - bytes -= copy; - } - - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - /* * Fault in the first iovec of the given iov_iter, to a maximum length * of bytes. Returns 0 on success, or non-zero if the memory could not be @@ -548,43 +504,6 @@ static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, return wanted; } -static size_t zero_bvec(size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, wanted; - const struct bio_vec *bvec; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - bvec = i->bvec; - skip = i->iov_offset; - copy = min_t(size_t, bytes, bvec->bv_len - skip); - - memzero_page(bvec->bv_page, skip + bvec->bv_offset, copy); - skip += copy; - bytes -= copy; - while (bytes) { - bvec++; - copy = min(bytes, (size_t)bvec->bv_len); - memzero_page(bvec->bv_page, bvec->bv_offset, copy); - skip = copy; - bytes -= copy; - } - if (skip == bvec->bv_len) { - bvec++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= bvec - i->bvec; - i->bvec = bvec; - i->iov_offset = skip; - return wanted - bytes; -} - size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { @@ -625,11 +544,18 @@ EXPORT_SYMBOL(copy_from_iter); size_t iov_iter_zero(size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) { - return zero_bvec(bytes, i); - } else { - return zero_iovec(bytes, i); - } + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + iterate_and_advance(i, bytes, v, + __clear_user(v.iov_base, v.iov_len), + memzero_page(v.bv_page, v.bv_offset, v.bv_len) + ) + + return bytes; } EXPORT_SYMBOL(iov_iter_zero); |