diff options
| author | David Howells <dhowells@redhat.com> | 2013-09-21 00:09:31 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2013-09-27 18:40:25 +0100 |
| commit | 8fb883f3e30065529e4f35d4b4f355193dcdb7a2 (patch) | |
| tree | 2a1096b66c9465539fb6e13daa16137d730f3ea3 /include/linux/fscache-cache.h | |
| parent | 2457aaf73a97a97c8596ed3903bd09601976f3bc (diff) | |
| download | linux-8fb883f3e30065529e4f35d4b4f355193dcdb7a2.tar.gz linux-8fb883f3e30065529e4f35d4b4f355193dcdb7a2.tar.bz2 linux-8fb883f3e30065529e4f35d4b4f355193dcdb7a2.zip | |
FS-Cache: Add use/unuse/wake cookie wrappers
Add wrapper functions for dealing with cookie->n_active:
(*) __fscache_use_cookie() to increment it.
(*) __fscache_unuse_cookie() to decrement and test against zero.
(*) __fscache_wake_unused_cookie() to wake up anyone waiting for it to reach
zero.
The second and third are split so that the third can be done after cookie->lock
has been released in case the waiter wakes up whilst we're still holding it and
tries to get it.
We will need to wake-on-zero once the cookie disablement patch is applied
because it will then be possible to see n_active become zero without the cookie
being relinquished.
Also move the cookie usement out of fscache_attr_changed_op() and into
fscache_attr_changed() and the operation struct so that cookie disablement
will be able to track it.
Whilst we're at it, only increment n_active if we're about to do
fscache_submit_op() so that we don't have to deal with undoing it if anything
earlier fails. Possibly this should be moved into fscache_submit_op() which
could look at FSCACHE_OP_UNUSE_COOKIE.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'include/linux/fscache-cache.h')
| -rw-r--r-- | include/linux/fscache-cache.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h index 7823e9ef995e..96a2b66f5968 100644 --- a/include/linux/fscache-cache.h +++ b/include/linux/fscache-cache.h @@ -511,6 +511,11 @@ static inline void fscache_end_io(struct fscache_retrieval *op, op->end_io_func(page, op->context, error); } +static inline void __fscache_use_cookie(struct fscache_cookie *cookie) +{ + atomic_inc(&cookie->n_active); +} + /** * fscache_use_cookie - Request usage of cookie attached to an object * @object: Object description @@ -524,6 +529,16 @@ static inline bool fscache_use_cookie(struct fscache_object *object) return atomic_inc_not_zero(&cookie->n_active) != 0; } +static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie) +{ + return atomic_dec_and_test(&cookie->n_active); +} + +static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie) +{ + wake_up_atomic_t(&cookie->n_active); +} + /** * fscache_unuse_cookie - Cease usage of cookie attached to an object * @object: Object description @@ -534,8 +549,8 @@ static inline bool fscache_use_cookie(struct fscache_object *object) static inline void fscache_unuse_cookie(struct fscache_object *object) { struct fscache_cookie *cookie = object->cookie; - if (atomic_dec_and_test(&cookie->n_active)) - wake_up_atomic_t(&cookie->n_active); + if (__fscache_unuse_cookie(cookie)) + __fscache_wake_unused_cookie(cookie); } /* |