diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 97003155bfac..908e75a28d90 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -461,6 +461,8 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { size_t n, copied = 0; + bool uses_kmap = IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || + PageHighMem(page); if (!page_copy_sane(page, offset, bytes)) return 0; @@ -471,7 +473,7 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset, char *p; n = bytes - copied; - if (PageHighMem(page)) { + if (uses_kmap) { page += offset / PAGE_SIZE; offset %= PAGE_SIZE; n = min_t(size_t, n, PAGE_SIZE - offset); @@ -482,7 +484,7 @@ size_t copy_page_from_iter_atomic(struct page *page, size_t offset, kunmap_atomic(p); copied += n; offset += n; - } while (PageHighMem(page) && copied != bytes && n > 0); + } while (uses_kmap && copied != bytes && n > 0); return copied; } @@ -1021,19 +1023,22 @@ static ssize_t iter_folioq_get_pages(struct iov_iter *iter, size_t offset = iov_offset, fsize = folioq_folio_size(folioq, slot); size_t part = PAGE_SIZE - offset % PAGE_SIZE; - part = umin(part, umin(maxsize - extracted, fsize - offset)); - count -= part; - iov_offset += part; - extracted += part; + if (offset < fsize) { + part = umin(part, umin(maxsize - extracted, fsize - offset)); + count -= part; + iov_offset += part; + extracted += part; + + *pages = folio_page(folio, offset / PAGE_SIZE); + get_page(*pages); + pages++; + maxpages--; + } - *pages = folio_page(folio, offset / PAGE_SIZE); - get_page(*pages); - pages++; - maxpages--; if (maxpages == 0 || extracted >= maxsize) break; - if (offset >= fsize) { + if (iov_offset >= fsize) { iov_offset = 0; slot++; if (slot == folioq_nr_slots(folioq) && folioq->next) { |