diff options
| -rw-r--r-- | include/linux/pagemap.h | 9 | ||||
| -rw-r--r-- | mm/filemap.c | 25 | ||||
| -rw-r--r-- | mm/shmem.c | 19 |
3 files changed, 30 insertions, 23 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 9d282fe6700d..5176009e4ffa 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -372,6 +372,15 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, mapping_gfp_mask(mapping)); } +/* Does this page contain this index? */ +static inline bool thp_contains(struct page *head, pgoff_t index) +{ + /* HugeTLBfs indexes the page cache in units of hpage_size */ + if (PageHuge(head)) + return head->index == index; + return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL)); +} + /* * Given the page we found in the page cache, return the page corresponding * to this index in the file diff --git a/mm/filemap.c b/mm/filemap.c index 9457d4f8b1c1..b44346a748fa 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1692,37 +1692,34 @@ out: } /** - * find_lock_entry - locate, pin and lock a page cache entry - * @mapping: the address_space to search - * @offset: the page cache index + * find_lock_entry - Locate and lock a page cache entry. + * @mapping: The address_space to search. + * @index: The page cache index. * - * Looks up the page cache slot at @mapping & @offset. If there is a - * page cache page, it is returned locked and with an increased - * refcount. + * Looks up the page at @mapping & @index. If there is a page in the + * cache, the head page is returned locked and with an increased refcount. * * If the slot holds a shadow entry of a previously evicted page, or a * swap entry from shmem/tmpfs, it is returned. * - * find_lock_entry() may sleep. - * - * Return: the found page or shadow entry, %NULL if nothing is found. + * Context: May sleep. + * Return: The head page or shadow entry, %NULL if nothing is found. */ -struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset) +struct page *find_lock_entry(struct address_space *mapping, pgoff_t index) { struct page *page; repeat: - page = find_get_entry(mapping, offset); + page = find_get_entry(mapping, index); if (page && !xa_is_value(page)) { lock_page(page); /* Has the page been truncated? */ - if (unlikely(page_mapping(page) != mapping)) { + if (unlikely(page->mapping != mapping)) { unlock_page(page); put_page(page); goto repeat; } - page = find_subpage(page, offset); - VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page); + VM_BUG_ON_PAGE(!thp_contains(page, index), page); } return page; } diff --git a/mm/shmem.c b/mm/shmem.c index d42c27e4769f..6d4ddef4a24f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1830,6 +1830,8 @@ repeat: return error; } + if (page) + hindex = page->index; if (page && sgp == SGP_WRITE) mark_page_accessed(page); @@ -1840,11 +1842,10 @@ repeat: unlock_page(page); put_page(page); page = NULL; + hindex = index; } - if (page || sgp == SGP_READ) { - *pagep = page; - return 0; - } + if (page || sgp == SGP_READ) + goto out; /* * Fast cache lookup did not find it: @@ -1969,14 +1970,13 @@ clear: * it now, lest undo on failure cancel our earlier guarantee. */ if (sgp != SGP_WRITE && !PageUptodate(page)) { - struct page *head = compound_head(page); int i; - for (i = 0; i < compound_nr(head); i++) { - clear_highpage(head + i); - flush_dcache_page(head + i); + for (i = 0; i < compound_nr(page); i++) { + clear_highpage(page + i); + flush_dcache_page(page + i); } - SetPageUptodate(head); + SetPageUptodate(page); } /* Perhaps the file has been truncated since we checked */ @@ -1992,6 +1992,7 @@ clear: error = -EINVAL; goto unlock; } +out: *pagep = page + index - hindex; return 0; |