--- zzzz-none-000/linux-3.10.107/include/linux/fscache-cache.h 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/include/linux/fscache-cache.h 2021-02-04 17:41:59.000000000 +0000 @@ -74,6 +74,7 @@ */ typedef void (*fscache_operation_release_t)(struct fscache_operation *op); typedef void (*fscache_operation_processor_t)(struct fscache_operation *op); +typedef void (*fscache_operation_cancel_t)(struct fscache_operation *op); enum fscache_operation_state { FSCACHE_OP_ST_BLANK, /* Op is not yet submitted */ @@ -97,7 +98,8 @@ #define FSCACHE_OP_WAITING 4 /* cleared when op is woken */ #define FSCACHE_OP_EXCLUSIVE 5 /* exclusive op, other ops must wait */ #define FSCACHE_OP_DEC_READ_CNT 6 /* decrement object->n_reads on destruction */ -#define FSCACHE_OP_KEEP_FLAGS 0x0070 /* flags to keep when repurposing an op */ +#define FSCACHE_OP_UNUSE_COOKIE 7 /* call fscache_unuse_cookie() on completion */ +#define FSCACHE_OP_KEEP_FLAGS 0x00f0 /* flags to keep when repurposing an op */ enum fscache_operation_state state; atomic_t usage; @@ -108,6 +110,9 @@ * the op in a non-pool thread */ fscache_operation_processor_t processor; + /* Operation cancellation cleanup (optional) */ + fscache_operation_cancel_t cancel; + /* operation releaser */ fscache_operation_release_t release; }; @@ -118,39 +123,23 @@ extern void fscache_enqueue_operation(struct fscache_operation *); extern void fscache_op_complete(struct fscache_operation *, bool); extern void fscache_put_operation(struct fscache_operation *); - -/** - * fscache_operation_init - Do basic initialisation of an operation - * @op: The operation to initialise - * @release: The release function to assign - * - * Do basic initialisation of an operation. The caller must still set flags, - * object and processor if needed. - */ -static inline void fscache_operation_init(struct fscache_operation *op, - fscache_operation_processor_t processor, - fscache_operation_release_t release) -{ - INIT_WORK(&op->work, fscache_op_work_func); - atomic_set(&op->usage, 1); - op->state = FSCACHE_OP_ST_INITIALISED; - op->debug_id = atomic_inc_return(&fscache_op_debug_id); - op->processor = processor; - op->release = release; - INIT_LIST_HEAD(&op->pend_link); -} +extern void fscache_operation_init(struct fscache_operation *, + fscache_operation_processor_t, + fscache_operation_cancel_t, + fscache_operation_release_t); /* * data read operation */ struct fscache_retrieval { struct fscache_operation op; + struct fscache_cookie *cookie; /* The netfs cookie */ struct address_space *mapping; /* netfs pages */ fscache_rw_complete_t end_io_func; /* function to call on I/O completion */ void *context; /* netfs read context (pinned) */ struct list_head to_do; /* list of things to be done by the backend */ unsigned long start_time; /* time at which retrieval started */ - unsigned n_pages; /* number of pages to be retrieved */ + atomic_t n_pages; /* number of pages to be retrieved */ }; typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op, @@ -194,15 +183,14 @@ static inline void fscache_retrieval_complete(struct fscache_retrieval *op, int n_pages) { - op->n_pages -= n_pages; - if (op->n_pages <= 0) + atomic_sub(n_pages, &op->n_pages); + if (atomic_read(&op->n_pages) <= 0) fscache_op_complete(&op->op, true); } /** * fscache_put_retrieval - Drop a reference to a retrieval operation * @op: The retrieval operation affected - * @n_pages: The number of pages to account for * * Drop a reference to a retrieval operation. */ @@ -251,6 +239,10 @@ /* unpin an object in the cache */ void (*unpin_object)(struct fscache_object *object); + /* check the consistency between the backing cache and the FS-Cache + * cookie */ + bool (*check_consistency)(struct fscache_operation *op); + /* store the updated auxiliary data on an object */ void (*update_object)(struct fscache_object *object); @@ -304,82 +296,46 @@ void (*dissociate_pages)(struct fscache_cache *cache); }; -/* - * data file or index object cookie - * - a file will only appear in one cache - * - a request to cache a file may or may not be honoured, subject to - * constraints such as disk space - * - indices are created on disk just-in-time - */ -struct fscache_cookie { - atomic_t usage; /* number of users of this cookie */ - atomic_t n_children; /* number of children of this cookie */ - spinlock_t lock; - spinlock_t stores_lock; /* lock on page store tree */ - struct hlist_head backing_objects; /* object(s) backing this file/index */ - const struct fscache_cookie_def *def; /* definition */ - struct fscache_cookie *parent; /* parent of this entry */ - void *netfs_data; /* back pointer to netfs */ - struct radix_tree_root stores; /* pages to be stored on this cookie */ -#define FSCACHE_COOKIE_PENDING_TAG 0 /* pages tag: pending write to cache */ -#define FSCACHE_COOKIE_STORING_TAG 1 /* pages tag: writing to cache */ - - unsigned long flags; -#define FSCACHE_COOKIE_LOOKING_UP 0 /* T if non-index cookie being looked up still */ -#define FSCACHE_COOKIE_CREATING 1 /* T if non-index object being created still */ -#define FSCACHE_COOKIE_NO_DATA_YET 2 /* T if new object with no cached data yet */ -#define FSCACHE_COOKIE_PENDING_FILL 3 /* T if pending initial fill on object */ -#define FSCACHE_COOKIE_FILLING 4 /* T if filling object incrementally */ -#define FSCACHE_COOKIE_UNAVAILABLE 5 /* T if cookie is unavailable (error, etc) */ -#define FSCACHE_COOKIE_WAITING_ON_READS 6 /* T if cookie is waiting on reads */ -#define FSCACHE_COOKIE_INVALIDATING 7 /* T if cookie is being invalidated */ -}; - extern struct fscache_cookie fscache_fsdef_index; /* * Event list for fscache_object::{event_mask,events} */ enum { - FSCACHE_OBJECT_EV_REQUEUE, /* T if object should be requeued */ + FSCACHE_OBJECT_EV_NEW_CHILD, /* T if object has a new child */ + FSCACHE_OBJECT_EV_PARENT_READY, /* T if object's parent is ready */ FSCACHE_OBJECT_EV_UPDATE, /* T if object should be updated */ FSCACHE_OBJECT_EV_INVALIDATE, /* T if cache requested object invalidation */ FSCACHE_OBJECT_EV_CLEARED, /* T if accessors all gone */ FSCACHE_OBJECT_EV_ERROR, /* T if fatal error occurred during processing */ - FSCACHE_OBJECT_EV_RELEASE, /* T if netfs requested object release */ - FSCACHE_OBJECT_EV_RETIRE, /* T if netfs requested object retirement */ - FSCACHE_OBJECT_EV_WITHDRAW, /* T if cache requested object withdrawal */ + FSCACHE_OBJECT_EV_KILL, /* T if netfs relinquished or cache withdrew object */ NR_FSCACHE_OBJECT_EVENTS }; #define FSCACHE_OBJECT_EVENTS_MASK ((1UL << NR_FSCACHE_OBJECT_EVENTS) - 1) /* + * States for object state machine. + */ +struct fscache_transition { + unsigned long events; + const struct fscache_state *transit_to; +}; + +struct fscache_state { + char name[24]; + char short_name[8]; + const struct fscache_state *(*work)(struct fscache_object *object, + int event); + const struct fscache_transition transitions[]; +}; + +/* * on-disk cache file or index handle */ struct fscache_object { - enum fscache_object_state { - FSCACHE_OBJECT_INIT, /* object in initial unbound state */ - FSCACHE_OBJECT_LOOKING_UP, /* looking up object */ - FSCACHE_OBJECT_CREATING, /* creating object */ - - /* active states */ - FSCACHE_OBJECT_AVAILABLE, /* cleaning up object after creation */ - FSCACHE_OBJECT_ACTIVE, /* object is usable */ - FSCACHE_OBJECT_INVALIDATING, /* object is invalidating */ - FSCACHE_OBJECT_UPDATING, /* object is updating */ - - /* terminal states */ - FSCACHE_OBJECT_DYING, /* object waiting for accessors to finish */ - FSCACHE_OBJECT_LC_DYING, /* object cleaning up after lookup/create */ - FSCACHE_OBJECT_ABORT_INIT, /* abort the init state */ - FSCACHE_OBJECT_RELEASING, /* releasing object */ - FSCACHE_OBJECT_RECYCLING, /* retiring object */ - FSCACHE_OBJECT_WITHDRAWING, /* withdrawing object */ - FSCACHE_OBJECT_DEAD, /* object is now dead */ - FSCACHE_OBJECT__NSTATES - } state; - + const struct fscache_state *state; /* Object state machine state */ + const struct fscache_transition *oob_table; /* OOB state transition table */ int debug_id; /* debugging ID */ int n_children; /* number of child objects */ int n_ops; /* number of extant ops on object */ @@ -390,6 +346,7 @@ spinlock_t lock; /* state and operations lock */ unsigned long lookup_jif; /* time at which lookup started */ + unsigned long oob_event_mask; /* OOB events this object is interested in */ unsigned long event_mask; /* events this object is interested in */ unsigned long events; /* events to be processed by this object * (order is important - using fls) */ @@ -398,6 +355,11 @@ #define FSCACHE_OBJECT_LOCK 0 /* T if object is busy being processed */ #define FSCACHE_OBJECT_PENDING_WRITE 1 /* T if object has pending write */ #define FSCACHE_OBJECT_WAITING 2 /* T if object is waiting on its parent */ +#define FSCACHE_OBJECT_IS_LIVE 3 /* T if object is not withdrawn or relinquished */ +#define FSCACHE_OBJECT_IS_LOOKED_UP 4 /* T if object has been looked up */ +#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */ +#define FSCACHE_OBJECT_RETIRED 6 /* T if object was retired on relinquishment */ +#define FSCACHE_OBJECT_KILLED_BY_CACHE 7 /* T if object was killed by the cache */ struct list_head cache_link; /* link in cache->object_list */ struct hlist_node cookie_link; /* link in cookie->backing_objects */ @@ -415,62 +377,39 @@ loff_t store_limit_l; /* current storage limit */ }; -extern const char *fscache_object_states[]; +extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *, + struct fscache_cache *); +extern void fscache_object_destroy(struct fscache_object *); -#define fscache_object_is_active(obj) \ - (!test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) && \ - (obj)->state >= FSCACHE_OBJECT_AVAILABLE && \ - (obj)->state < FSCACHE_OBJECT_DYING) - -#define fscache_object_is_dead(obj) \ - (test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) && \ - (obj)->state >= FSCACHE_OBJECT_DYING) +extern void fscache_object_lookup_negative(struct fscache_object *object); +extern void fscache_obtained_object(struct fscache_object *object); -extern void fscache_object_work_func(struct work_struct *work); +static inline bool fscache_object_is_live(struct fscache_object *object) +{ + return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags); +} -/** - * fscache_object_init - Initialise a cache object description - * @object: Object description - * - * Initialise a cache object description to its basic values. - * - * See Documentation/filesystems/caching/backend-api.txt for a complete - * description. - */ -static inline -void fscache_object_init(struct fscache_object *object, - struct fscache_cookie *cookie, - struct fscache_cache *cache) -{ - atomic_inc(&cache->object_count); - - object->state = FSCACHE_OBJECT_INIT; - spin_lock_init(&object->lock); - INIT_LIST_HEAD(&object->cache_link); - INIT_HLIST_NODE(&object->cookie_link); - INIT_WORK(&object->work, fscache_object_work_func); - INIT_LIST_HEAD(&object->dependents); - INIT_LIST_HEAD(&object->dep_link); - INIT_LIST_HEAD(&object->pending_ops); - object->n_children = 0; - object->n_ops = object->n_in_progress = object->n_exclusive = 0; - object->events = object->event_mask = 0; - object->flags = 0; - object->store_limit = 0; - object->store_limit_l = 0; - object->cache = cache; - object->cookie = cookie; - object->parent = NULL; +static inline bool fscache_object_is_dying(struct fscache_object *object) +{ + return !fscache_object_is_live(object); } -extern void fscache_object_lookup_negative(struct fscache_object *object); -extern void fscache_obtained_object(struct fscache_object *object); +static inline bool fscache_object_is_available(struct fscache_object *object) +{ + return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags); +} -#ifdef CONFIG_FSCACHE_OBJECT_LIST -extern void fscache_object_destroy(struct fscache_object *object); -#else -#define fscache_object_destroy(object) do {} while(0) -#endif +static inline bool fscache_cache_is_broken(struct fscache_object *object) +{ + return test_bit(FSCACHE_IOERROR, &object->cache->flags); +} + +static inline bool fscache_object_is_active(struct fscache_object *object) +{ + return fscache_object_is_available(object) && + fscache_object_is_live(object) && + !fscache_cache_is_broken(object); +} /** * fscache_object_destroyed - Note destruction of an object in a cache @@ -531,6 +470,48 @@ 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 + * + * Request usage of the cookie attached to an object. NULL is returned if the + * relinquishment had reduced the cookie usage count to 0. + */ +static inline bool fscache_use_cookie(struct fscache_object *object) +{ + struct fscache_cookie *cookie = object->cookie; + 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 + * + * Cease usage of the cookie attached to an object. When the users count + * reaches zero then the cookie relinquishment will be permitted to proceed. + */ +static inline void fscache_unuse_cookie(struct fscache_object *object) +{ + struct fscache_cookie *cookie = object->cookie; + if (__fscache_unuse_cookie(cookie)) + __fscache_wake_unused_cookie(cookie); +} + /* * out-of-line cache backend functions */ @@ -558,4 +539,15 @@ const void *data, uint16_t datalen); +extern void fscache_object_retrying_stale(struct fscache_object *object); + +enum fscache_why_object_killed { + FSCACHE_OBJECT_IS_STALE, + FSCACHE_OBJECT_NO_SPACE, + FSCACHE_OBJECT_WAS_RETIRED, + FSCACHE_OBJECT_WAS_CULLED, +}; +extern void fscache_object_mark_killed(struct fscache_object *object, + enum fscache_why_object_killed why); + #endif /* _LINUX_FSCACHE_CACHE_H */