diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fscache.h | 84 | ||||
| -rw-r--r-- | include/trace/events/fscache.h | 61 |
2 files changed, 144 insertions, 1 deletions
diff --git a/include/linux/fscache.h b/include/linux/fscache.h index 1cf90c252aac..131a741a6652 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -20,13 +20,97 @@ #if defined(CONFIG_FSCACHE) || defined(CONFIG_FSCACHE_MODULE) #define __fscache_available (1) #define fscache_available() (1) +#define fscache_volume_valid(volume) (volume) #define fscache_cookie_valid(cookie) (cookie) #define fscache_cookie_enabled(cookie) (cookie) #else #define __fscache_available (0) #define fscache_available() (0) +#define fscache_volume_valid(volume) (0) #define fscache_cookie_valid(cookie) (0) #define fscache_cookie_enabled(cookie) (0) #endif +/* + * Volume representation cookie. + */ +struct fscache_volume { + refcount_t ref; + atomic_t n_cookies; /* Number of data cookies in volume */ + atomic_t n_accesses; /* Number of cache accesses in progress */ + unsigned int debug_id; + unsigned int key_hash; /* Hash of key string */ + char *key; /* Volume ID, eg. "afs@example.com@1234" */ + struct list_head proc_link; /* Link in /proc/fs/fscache/volumes */ + struct hlist_bl_node hash_link; /* Link in hash table */ + struct work_struct work; + struct fscache_cache *cache; /* The cache in which this resides */ + void *cache_priv; /* Cache private data */ + spinlock_t lock; + unsigned long flags; +#define FSCACHE_VOLUME_RELINQUISHED 0 /* Volume is being cleaned up */ +#define FSCACHE_VOLUME_INVALIDATE 1 /* Volume was invalidated */ +#define FSCACHE_VOLUME_COLLIDED_WITH 2 /* Volume was collided with */ +#define FSCACHE_VOLUME_ACQUIRE_PENDING 3 /* Volume is waiting to complete acquisition */ +#define FSCACHE_VOLUME_CREATING 4 /* Volume is being created on disk */ +}; + +/* + * slow-path functions for when there is actually caching available, and the + * netfs does actually have a valid token + * - these are not to be called directly + * - these are undefined symbols when FS-Cache is not configured and the + * optimiser takes care of not using them + */ +extern struct fscache_volume *__fscache_acquire_volume(const char *, const char *, + const void *, size_t); +extern void __fscache_relinquish_volume(struct fscache_volume *, const void *, bool); + +/** + * fscache_acquire_volume - Register a volume as desiring caching services + * @volume_key: An identification string for the volume + * @cache_name: The name of the cache to use (or NULL for the default) + * @coherency_data: Piece of arbitrary coherency data to check (or NULL) + * @coherency_len: The size of the coherency data + * + * Register a volume as desiring caching services if they're available. The + * caller must provide an identifier for the volume and may also indicate which + * cache it should be in. If a preexisting volume entry is found in the cache, + * the coherency data must match otherwise the entry will be invalidated. + * + * Returns a cookie pointer on success, -ENOMEM if out of memory or -EBUSY if a + * cache volume of that name is already acquired. Note that "NULL" is a valid + * cookie pointer and can be returned if caching is refused. + */ +static inline +struct fscache_volume *fscache_acquire_volume(const char *volume_key, + const char *cache_name, + const void *coherency_data, + size_t coherency_len) +{ + if (!fscache_available()) + return NULL; + return __fscache_acquire_volume(volume_key, cache_name, + coherency_data, coherency_len); +} + +/** + * fscache_relinquish_volume - Cease caching a volume + * @volume: The volume cookie + * @coherency_data: Piece of arbitrary coherency data to set (or NULL) + * @invalidate: True if the volume should be invalidated + * + * Indicate that a filesystem no longer desires caching services for a volume. + * The caller must have relinquished all file cookies prior to calling this. + * The stored coherency data is updated. + */ +static inline +void fscache_relinquish_volume(struct fscache_volume *volume, + const void *coherency_data, + bool invalidate) +{ + if (fscache_volume_valid(volume)) + __fscache_relinquish_volume(volume, coherency_data, invalidate); +} + #endif /* _LINUX_FSCACHE_H */ diff --git a/include/trace/events/fscache.h b/include/trace/events/fscache.h index 3b8e0597b2c1..eeb3e7d88e20 100644 --- a/include/trace/events/fscache.h +++ b/include/trace/events/fscache.h @@ -23,9 +23,26 @@ enum fscache_cache_trace { fscache_cache_collision, fscache_cache_get_acquire, fscache_cache_new_acquire, + fscache_cache_put_alloc_volume, fscache_cache_put_cache, fscache_cache_put_prep_failed, fscache_cache_put_relinquish, + fscache_cache_put_volume, +}; + +enum fscache_volume_trace { + fscache_volume_collision, + fscache_volume_get_cookie, + fscache_volume_get_create_work, + fscache_volume_get_hash_collision, + fscache_volume_free, + fscache_volume_new_acquire, + fscache_volume_put_cookie, + fscache_volume_put_create_work, + fscache_volume_put_hash_collision, + fscache_volume_put_relinquish, + fscache_volume_see_create_work, + fscache_volume_see_hash_wake, }; #endif @@ -37,9 +54,25 @@ enum fscache_cache_trace { EM(fscache_cache_collision, "*COLLIDE*") \ EM(fscache_cache_get_acquire, "GET acq ") \ EM(fscache_cache_new_acquire, "NEW acq ") \ + EM(fscache_cache_put_alloc_volume, "PUT alvol") \ EM(fscache_cache_put_cache, "PUT cache") \ EM(fscache_cache_put_prep_failed, "PUT pfail") \ - E_(fscache_cache_put_relinquish, "PUT relnq") + EM(fscache_cache_put_relinquish, "PUT relnq") \ + E_(fscache_cache_put_volume, "PUT vol ") + +#define fscache_volume_traces \ + EM(fscache_volume_collision, "*COLLIDE*") \ + EM(fscache_volume_get_cookie, "GET cook ") \ + EM(fscache_volume_get_create_work, "GET creat") \ + EM(fscache_volume_get_hash_collision, "GET hcoll") \ + EM(fscache_volume_free, "FREE ") \ + EM(fscache_volume_new_acquire, "NEW acq ") \ + EM(fscache_volume_put_cookie, "PUT cook ") \ + EM(fscache_volume_put_create_work, "PUT creat") \ + EM(fscache_volume_put_hash_collision, "PUT hcoll") \ + EM(fscache_volume_put_relinquish, "PUT relnq") \ + EM(fscache_volume_see_create_work, "SEE creat") \ + E_(fscache_volume_see_hash_wake, "SEE hwake") /* * Export enum symbols via userspace. @@ -50,6 +83,7 @@ enum fscache_cache_trace { #define E_(a, b) TRACE_DEFINE_ENUM(a); fscache_cache_traces; +fscache_volume_traces; /* * Now redefine the EM() and E_() macros to map the enums to the strings that @@ -86,6 +120,31 @@ TRACE_EVENT(fscache_cache, __entry->usage) ); +TRACE_EVENT(fscache_volume, + TP_PROTO(unsigned int volume_debug_id, + int usage, + enum fscache_volume_trace where), + + TP_ARGS(volume_debug_id, usage, where), + + TP_STRUCT__entry( + __field(unsigned int, volume ) + __field(int, usage ) + __field(enum fscache_volume_trace, where ) + ), + + TP_fast_assign( + __entry->volume = volume_debug_id; + __entry->usage = usage; + __entry->where = where; + ), + + TP_printk("V=%08x %s u=%d", + __entry->volume, + __print_symbolic(__entry->where, fscache_volume_traces), + __entry->usage) + ); + #endif /* _TRACE_FSCACHE_H */ /* This part must be outside protection */ |