diff options
Diffstat (limited to 'include/linux/fscache.h')
| -rw-r--r-- | include/linux/fscache.h | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/include/linux/fscache.h b/include/linux/fscache.h index 6d8ee466e0a0..ec0dad5ab90f 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -85,7 +85,7 @@ struct fscache_cookie_def { /* get an index key * - should store the key data in the buffer - * - should return the amount of amount stored + * - should return the amount of data stored * - not permitted to return an error * - the netfs data from the cookie being used as the source is * presented @@ -202,6 +202,8 @@ extern int __fscache_write_page(struct fscache_cookie *, struct page *, gfp_t); extern void __fscache_uncache_page(struct fscache_cookie *, struct page *); extern bool __fscache_check_page_write(struct fscache_cookie *, struct page *); extern void __fscache_wait_on_page_write(struct fscache_cookie *, struct page *); +extern bool __fscache_maybe_release_page(struct fscache_cookie *, struct page *, + gfp_t); /** * fscache_register_netfs - Register a filesystem as desiring caching services @@ -452,6 +454,7 @@ int fscache_read_or_alloc_page(struct fscache_cookie *cookie, * @cookie: The cookie representing the cache object * @mapping: The netfs inode mapping to which the pages will be attached * @pages: A list of potential netfs pages to be filled + * @nr_pages: Number of pages to be read and/or allocated * @end_io_func: The callback to invoke when and if each page is filled * @context: An arbitrary piece of data to pass on to end_io_func() * @gfp: The conditions under which memory allocation should be made @@ -615,4 +618,29 @@ void fscache_wait_on_page_write(struct fscache_cookie *cookie, __fscache_wait_on_page_write(cookie, page); } +/** + * fscache_maybe_release_page - Consider releasing a page, cancelling a store + * @cookie: The cookie representing the cache object + * @page: The netfs page that is being cached. + * @gfp: The gfp flags passed to releasepage() + * + * Consider releasing a page for the vmscan algorithm, on behalf of the netfs's + * releasepage() call. A storage request on the page may cancelled if it is + * not currently being processed. + * + * The function returns true if the page no longer has a storage request on it, + * and false if a storage request is left in place. If true is returned, the + * page will have been passed to fscache_uncache_page(). If false is returned + * the page cannot be freed yet. + */ +static inline +bool fscache_maybe_release_page(struct fscache_cookie *cookie, + struct page *page, + gfp_t gfp) +{ + if (fscache_cookie_valid(cookie) && PageFsCache(page)) + return __fscache_maybe_release_page(cookie, page, gfp); + return false; +} + #endif /* _LINUX_FSCACHE_H */ |