diff options
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 65 |
1 files changed, 38 insertions, 27 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index bec83c15a78..133b6d52551 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -17,19 +17,6 @@ #include <linux/pagevec.h> #include <linux/pagemap.h> -void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) -{ -} -EXPORT_SYMBOL(default_unplug_io_fn); - -struct backing_dev_info default_backing_dev_info = { - .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE, - .state = 0, - .capabilities = BDI_CAP_MAP_COPY, - .unplug_io_fn = default_unplug_io_fn, -}; -EXPORT_SYMBOL_GPL(default_backing_dev_info); - /* * Initialise a struct file's readahead state. Assumes that the caller has * memset *ra to zero. @@ -44,6 +31,42 @@ EXPORT_SYMBOL_GPL(file_ra_state_init); #define list_to_page(head) (list_entry((head)->prev, struct page, lru)) +/* + * see if a page needs releasing upon read_cache_pages() failure + * - the caller of read_cache_pages() may have set PG_private or PG_fscache + * before calling, such as the NFS fs marking pages that are cached locally + * on disk, thus we need to give the fs a chance to clean up in the event of + * an error + */ +static void read_cache_pages_invalidate_page(struct address_space *mapping, + struct page *page) +{ + if (page_has_private(page)) { + if (!trylock_page(page)) + BUG(); + page->mapping = mapping; + do_invalidatepage(page, 0); + page->mapping = NULL; + unlock_page(page); + } + page_cache_release(page); +} + +/* + * release a list of pages, invalidating them first if need be + */ +static void read_cache_pages_invalidate_pages(struct address_space *mapping, + struct list_head *pages) +{ + struct page *victim; + + while (!list_empty(pages)) { + victim = list_to_page(pages); + list_del(&victim->lru); + read_cache_pages_invalidate_page(mapping, victim); + } +} + /** * read_cache_pages - populate an address space with some pages & start reads against them * @mapping: the address_space @@ -65,14 +88,14 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages, list_del(&page->lru); if (add_to_page_cache_lru(page, mapping, page->index, GFP_KERNEL)) { - page_cache_release(page); + read_cache_pages_invalidate_page(mapping, page); continue; } page_cache_release(page); ret = filler(data, page); if (unlikely(ret)) { - put_pages_list(pages); + read_cache_pages_invalidate_pages(mapping, pages); break; } task_io_account_read(PAGE_CACHE_SIZE); @@ -233,18 +256,6 @@ unsigned long max_sane_readahead(unsigned long nr) + node_page_state(numa_node_id(), NR_FREE_PAGES)) / 2); } -static int __init readahead_init(void) -{ - int err; - - err = bdi_init(&default_backing_dev_info); - if (!err) - bdi_register(&default_backing_dev_info, NULL, "default"); - - return err; -} -subsys_initcall(readahead_init); - /* * Submit IO for the read-ahead request in file_ra_state. */ |