diff options
| -rw-r--r-- | mm/iov_iter.c | 73 |
1 files changed, 19 insertions, 54 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c index e91bf0accc47..bc666e79b5bd 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -493,32 +493,6 @@ static ssize_t get_pages_alloc_iovec(struct iov_iter *i, return (res == n ? len : res * PAGE_SIZE) - *start; } -static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages) -{ - size_t offset = i->iov_offset; - size_t size = i->count; - const struct iovec *iov = i->iov; - int npages = 0; - int n; - - for (n = 0; size && n < i->nr_segs; n++, iov++) { - unsigned long addr = (unsigned long)iov->iov_base + offset; - size_t len = iov->iov_len - offset; - offset = 0; - if (unlikely(!len)) /* empty segment */ - continue; - if (len > size) - len = size; - npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE - - addr / PAGE_SIZE; - if (npages >= maxpages) /* don't bother going further */ - return maxpages; - size -= len; - offset = 0; - } - return min(npages, maxpages); -} - static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) { char *from = kmap_atomic(page); @@ -715,30 +689,6 @@ static ssize_t get_pages_alloc_bvec(struct iov_iter *i, return len; } -static int iov_iter_npages_bvec(const struct iov_iter *i, int maxpages) -{ - size_t offset = i->iov_offset; - size_t size = i->count; - const struct bio_vec *bvec = i->bvec; - int npages = 0; - int n; - - for (n = 0; size && n < i->nr_segs; n++, bvec++) { - size_t len = bvec->bv_len - offset; - offset = 0; - if (unlikely(!len)) /* empty segment */ - continue; - if (len > size) - len = size; - npages++; - if (npages >= maxpages) /* don't bother going further */ - return maxpages; - size -= len; - offset = 0; - } - return min(npages, maxpages); -} - size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { @@ -862,9 +812,24 @@ EXPORT_SYMBOL(iov_iter_get_pages_alloc); int iov_iter_npages(const struct iov_iter *i, int maxpages) { - if (i->type & ITER_BVEC) - return iov_iter_npages_bvec(i, maxpages); - else - return iov_iter_npages_iovec(i, maxpages); + size_t size = i->count; + int npages = 0; + + if (!size) + return 0; + + iterate_all_kinds(i, size, v, ({ + unsigned long p = (unsigned long)v.iov_base; + npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) + - p / PAGE_SIZE; + if (npages >= maxpages) + return maxpages; + 0;}),({ + npages++; + if (npages >= maxpages) + return maxpages; + }) + ) + return npages; } EXPORT_SYMBOL(iov_iter_npages); |