Provide a function to be called from a network filesystem's releasepage method to indicate that a page has been released that might have been a reflection of data upon the server - and now that data must be reloaded from the server or the cache. This is used to end an optimisation for empty files, in particular files that have just been created locally, whereby we know there cannot yet be any data that we would need to read from the server or the cache. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: linux-cachefs@xxxxxxxxxx Link: https://lore.kernel.org/r/163819617128.215744.4725572296135656508.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1 --- include/linux/fscache.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/include/linux/fscache.h b/include/linux/fscache.h index 73942b4e9aee..fed7def0fbe0 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -603,4 +603,20 @@ static inline void fscache_clear_inode_writeback(struct fscache_cookie *cookie, } } +/** + * fscache_note_page_release - Note that a netfs page got released + * @cookie: The cookie corresponding to the file + * + * Note that a page that has been copied to the cache has been released. This + * means that future reads will need to look in the cache to see if it's there. + */ +static inline +void fscache_note_page_release(struct fscache_cookie *cookie) +{ + if (cookie && + test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) && + test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) + clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags); +} + #endif /* _LINUX_FSCACHE_H */
