diff options
author | David Howells <dhowells@redhat.com> | 2021-10-20 15:00:26 +0100 |
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committer | David Howells <dhowells@redhat.com> | 2022-01-07 09:22:19 +0000 |
commit | 9549332df4ed4e761a1d41c83f2c25d28bb22431 (patch) | |
tree | c1f3785ea480de4757f15cb125082a5ed786d202 /fs/fscache/internal.h | |
parent | e8a07c9d22afdace966353231d0273d29efe0890 (diff) |
fscache: Implement cache registration
Implement a register of caches and provide functions to manage it.
Two functions are provided for the cache backend to use:
(1) Acquire a cache cookie:
struct fscache_cache *fscache_acquire_cache(const char *name)
This gets the cache cookie for a cache of the specified name and moves
it to the preparation state. If a nameless cache cookie exists, that
will be given this name and used.
(2) Relinquish a cache cookie:
void fscache_relinquish_cache(struct fscache_cache *cache);
This relinquishes a cache cookie, cleans it and makes it available if
it's still referenced by a network filesystem.
Note that network filesystems don't deal with cache cookies directly, but
rather go straight to the volume registration.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819587157.215744.13523139317322503286.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906889665.143852.10378009165231294456.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967085081.1823006.2218944206363626210.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021494847.640689.10109692261640524343.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/fscache/internal.h')
-rw-r--r-- | fs/fscache/internal.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h index f345bdb018ba..8fd39e7735fc 100644 --- a/fs/fscache/internal.h +++ b/fs/fscache/internal.h @@ -18,6 +18,39 @@ #include <linux/seq_file.h> /* + * cache.c + */ +#ifdef CONFIG_PROC_FS +extern const struct seq_operations fscache_caches_seq_ops; +#endif +struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache); +void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where); + +static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache) +{ + return smp_load_acquire(&cache->state); +} + +static inline bool fscache_cache_is_live(const struct fscache_cache *cache) +{ + return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE; +} + +static inline void fscache_set_cache_state(struct fscache_cache *cache, + enum fscache_cache_state new_state) +{ + smp_store_release(&cache->state, new_state); + +} + +static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache, + enum fscache_cache_state old_state, + enum fscache_cache_state new_state) +{ + return try_cmpxchg_release(&cache->state, &old_state, new_state); +} + +/* * main.c */ extern unsigned fscache_debug; |