diff options
| -rw-r--r-- | include/linux/pagemap.h | 12 | ||||
| -rw-r--r-- | include/linux/pagevec.h | 13 | ||||
| -rw-r--r-- | mm/filemap.c | 42 | ||||
| -rw-r--r-- | mm/swap.c | 22 |
4 files changed, 65 insertions, 24 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 249b1b5964c7..5bbd6780f205 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -353,8 +353,16 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset); unsigned find_get_entries(struct address_space *mapping, pgoff_t start, unsigned int nr_entries, struct page **entries, pgoff_t *indices); -unsigned find_get_pages(struct address_space *mapping, pgoff_t *start, - unsigned int nr_pages, struct page **pages); +unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, + pgoff_t end, unsigned int nr_pages, + struct page **pages); +static inline unsigned find_get_pages(struct address_space *mapping, + pgoff_t *start, unsigned int nr_pages, + struct page **pages) +{ + return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages, + pages); +} unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start, unsigned int nr_pages, struct page **pages); unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index, diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index c395a5bb58b2..7df056910437 100644 --- a/include/linux/pagevec.h +++ b/include/linux/pagevec.h @@ -27,8 +27,17 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec, pgoff_t start, unsigned nr_entries, pgoff_t *indices); void pagevec_remove_exceptionals(struct pagevec *pvec); -unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, - pgoff_t *start, unsigned nr_pages); +unsigned pagevec_lookup_range(struct pagevec *pvec, + struct address_space *mapping, + pgoff_t *start, pgoff_t end, unsigned nr_pages); +static inline unsigned pagevec_lookup(struct pagevec *pvec, + struct address_space *mapping, + pgoff_t *start, unsigned nr_pages) +{ + return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1, + nr_pages); +} + unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, int tag, unsigned nr_pages); diff --git a/mm/filemap.c b/mm/filemap.c index ab9011408d81..129883f160a7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1557,24 +1557,29 @@ export: } /** - * find_get_pages - gang pagecache lookup + * find_get_pages_range - gang pagecache lookup * @mapping: The address_space to search * @start: The starting page index + * @end: The final page index (inclusive) * @nr_pages: The maximum number of pages * @pages: Where the resulting pages are placed * - * find_get_pages() will search for and return a group of up to - * @nr_pages pages in the mapping. The pages are placed at @pages. - * find_get_pages() takes a reference against the returned pages. + * find_get_pages_range() will search for and return a group of up to @nr_pages + * pages in the mapping starting at index @start and up to index @end + * (inclusive). The pages are placed at @pages. find_get_pages_range() takes + * a reference against the returned pages. * * The search returns a group of mapping-contiguous pages with ascending * indexes. There may be holes in the indices due to not-present pages. * We also update @start to index the next page for the traversal. * - * find_get_pages() returns the number of pages which were found. + * find_get_pages_range() returns the number of pages which were found. If this + * number is smaller than @nr_pages, the end of specified range has been + * reached. */ -unsigned find_get_pages(struct address_space *mapping, pgoff_t *start, - unsigned int nr_pages, struct page **pages) +unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, + pgoff_t end, unsigned int nr_pages, + struct page **pages) { struct radix_tree_iter iter; void **slot; @@ -1586,6 +1591,9 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t *start, rcu_read_lock(); radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, *start) { struct page *head, *page; + + if (iter.index > end) + break; repeat: page = radix_tree_deref_slot(slot); if (unlikely(!page)) @@ -1621,15 +1629,25 @@ repeat: } pages[ret] = page; - if (++ret == nr_pages) - break; + if (++ret == nr_pages) { + *start = pages[ret - 1]->index + 1; + goto out; + } } + /* + * We come here when there is no page beyond @end. We take care to not + * overflow the index @start as it confuses some of the callers. This + * breaks the iteration when there is page at index -1 but that is + * already broken anyway. + */ + if (end == (pgoff_t)-1) + *start = (pgoff_t)-1; + else + *start = end + 1; +out: rcu_read_unlock(); - if (ret) - *start = pages[ret - 1]->index + 1; - return ret; } diff --git a/mm/swap.c b/mm/swap.c index 4bffd1198ce5..e06e9aa2478e 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -946,29 +946,35 @@ void pagevec_remove_exceptionals(struct pagevec *pvec) } /** - * pagevec_lookup - gang pagecache lookup + * pagevec_lookup_range - gang pagecache lookup * @pvec: Where the resulting pages are placed * @mapping: The address_space to search * @start: The starting page index + * @end: The final page index * @nr_pages: The maximum number of pages * - * pagevec_lookup() will search for and return a group of up to @nr_pages pages - * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a + * pagevec_lookup_range() will search for and return a group of up to @nr_pages + * pages in the mapping starting from index @start and upto index @end + * (inclusive). The pages are placed in @pvec. pagevec_lookup() takes a * reference against the pages in @pvec. * * The search returns a group of mapping-contiguous pages with ascending * indexes. There may be holes in the indices due to not-present pages. We * also update @start to index the next page for the traversal. * - * pagevec_lookup() returns the number of pages which were found. + * pagevec_lookup_range() returns the number of pages which were found. If this + * number is smaller than @nr_pages, the end of specified range has been + * reached. */ -unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, - pgoff_t *start, unsigned nr_pages) +unsigned pagevec_lookup_range(struct pagevec *pvec, + struct address_space *mapping, pgoff_t *start, pgoff_t end, + unsigned nr_pages) { - pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); + pvec->nr = find_get_pages_range(mapping, start, end, nr_pages, + pvec->pages); return pagevec_count(pvec); } -EXPORT_SYMBOL(pagevec_lookup); +EXPORT_SYMBOL(pagevec_lookup_range); unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, int tag, unsigned nr_pages) |