diff options
Diffstat (limited to 'ANDROID_3.4.5/include/linux/fscache-cache.h')
| -rw-r--r-- | ANDROID_3.4.5/include/linux/fscache-cache.h | 516 |
1 files changed, 0 insertions, 516 deletions
diff --git a/ANDROID_3.4.5/include/linux/fscache-cache.h b/ANDROID_3.4.5/include/linux/fscache-cache.h deleted file mode 100644 index ce31408b..00000000 --- a/ANDROID_3.4.5/include/linux/fscache-cache.h +++ /dev/null @@ -1,516 +0,0 @@ -/* General filesystem caching backing cache interface - * - * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * - * NOTE!!! See: - * - * Documentation/filesystems/caching/backend-api.txt - * - * for a description of the cache backend interface declared here. - */ - -#ifndef _LINUX_FSCACHE_CACHE_H -#define _LINUX_FSCACHE_CACHE_H - -#include <linux/fscache.h> -#include <linux/sched.h> -#include <linux/workqueue.h> - -#define NR_MAXCACHES BITS_PER_LONG - -struct fscache_cache; -struct fscache_cache_ops; -struct fscache_object; -struct fscache_operation; - -/* - * cache tag definition - */ -struct fscache_cache_tag { - struct list_head link; - struct fscache_cache *cache; /* cache referred to by this tag */ - unsigned long flags; -#define FSCACHE_TAG_RESERVED 0 /* T if tag is reserved for a cache */ - atomic_t usage; - char name[0]; /* tag name */ -}; - -/* - * cache definition - */ -struct fscache_cache { - const struct fscache_cache_ops *ops; - struct fscache_cache_tag *tag; /* tag representing this cache */ - struct kobject *kobj; /* system representation of this cache */ - struct list_head link; /* link in list of caches */ - size_t max_index_size; /* maximum size of index data */ - char identifier[36]; /* cache label */ - - /* node management */ - struct work_struct op_gc; /* operation garbage collector */ - struct list_head object_list; /* list of data/index objects */ - struct list_head op_gc_list; /* list of ops to be deleted */ - spinlock_t object_list_lock; - spinlock_t op_gc_list_lock; - atomic_t object_count; /* no. of live objects in this cache */ - struct fscache_object *fsdef; /* object for the fsdef index */ - unsigned long flags; -#define FSCACHE_IOERROR 0 /* cache stopped on I/O error */ -#define FSCACHE_CACHE_WITHDRAWN 1 /* cache has been withdrawn */ -}; - -extern wait_queue_head_t fscache_cache_cleared_wq; - -/* - * operation to be applied to a cache object - * - retrieval initiation operations are done in the context of the process - * that issued them, and not in an async thread pool - */ -typedef void (*fscache_operation_release_t)(struct fscache_operation *op); -typedef void (*fscache_operation_processor_t)(struct fscache_operation *op); - -struct fscache_operation { - struct work_struct work; /* record for async ops */ - struct list_head pend_link; /* link in object->pending_ops */ - struct fscache_object *object; /* object to be operated upon */ - - unsigned long flags; -#define FSCACHE_OP_TYPE 0x000f /* operation type */ -#define FSCACHE_OP_ASYNC 0x0001 /* - async op, processor may sleep for disk */ -#define FSCACHE_OP_MYTHREAD 0x0002 /* - processing is done be issuing thread, not pool */ -#define FSCACHE_OP_WAITING 4 /* cleared when op is woken */ -#define FSCACHE_OP_EXCLUSIVE 5 /* exclusive op, other ops must wait */ -#define FSCACHE_OP_DEAD 6 /* op is now dead */ -#define FSCACHE_OP_DEC_READ_CNT 7 /* decrement object->n_reads on destruction */ -#define FSCACHE_OP_KEEP_FLAGS 0xc0 /* flags to keep when repurposing an op */ - - atomic_t usage; - unsigned debug_id; /* debugging ID */ - - /* operation processor callback - * - can be NULL if FSCACHE_OP_WAITING is going to be used to perform - * the op in a non-pool thread */ - fscache_operation_processor_t processor; - - /* operation releaser */ - fscache_operation_release_t release; -}; - -extern atomic_t fscache_op_debug_id; -extern void fscache_op_work_func(struct work_struct *work); - -extern void fscache_enqueue_operation(struct fscache_operation *); -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->debug_id = atomic_inc_return(&fscache_op_debug_id); - op->processor = processor; - op->release = release; - INIT_LIST_HEAD(&op->pend_link); -} - -/* - * data read operation - */ -struct fscache_retrieval { - struct fscache_operation op; - 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 */ -}; - -typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op, - struct page *page, - gfp_t gfp); - -typedef int (*fscache_pages_retrieval_func_t)(struct fscache_retrieval *op, - struct list_head *pages, - unsigned *nr_pages, - gfp_t gfp); - -/** - * fscache_get_retrieval - Get an extra reference on a retrieval operation - * @op: The retrieval operation to get a reference on - * - * Get an extra reference on a retrieval operation. - */ -static inline -struct fscache_retrieval *fscache_get_retrieval(struct fscache_retrieval *op) -{ - atomic_inc(&op->op.usage); - return op; -} - -/** - * fscache_enqueue_retrieval - Enqueue a retrieval operation for processing - * @op: The retrieval operation affected - * - * Enqueue a retrieval operation for processing by the FS-Cache thread pool. - */ -static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op) -{ - fscache_enqueue_operation(&op->op); -} - -/** - * fscache_put_retrieval - Drop a reference to a retrieval operation - * @op: The retrieval operation affected - * - * Drop a reference to a retrieval operation. - */ -static inline void fscache_put_retrieval(struct fscache_retrieval *op) -{ - fscache_put_operation(&op->op); -} - -/* - * cached page storage work item - * - used to do three things: - * - batch writes to the cache - * - do cache writes asynchronously - * - defer writes until cache object lookup completion - */ -struct fscache_storage { - struct fscache_operation op; - pgoff_t store_limit; /* don't write more than this */ -}; - -/* - * cache operations - */ -struct fscache_cache_ops { - /* name of cache provider */ - const char *name; - - /* allocate an object record for a cookie */ - struct fscache_object *(*alloc_object)(struct fscache_cache *cache, - struct fscache_cookie *cookie); - - /* look up the object for a cookie - * - return -ETIMEDOUT to be requeued - */ - int (*lookup_object)(struct fscache_object *object); - - /* finished looking up */ - void (*lookup_complete)(struct fscache_object *object); - - /* increment the usage count on this object (may fail if unmounting) */ - struct fscache_object *(*grab_object)(struct fscache_object *object); - - /* pin an object in the cache */ - int (*pin_object)(struct fscache_object *object); - - /* unpin an object in the cache */ - void (*unpin_object)(struct fscache_object *object); - - /* store the updated auxiliary data on an object */ - void (*update_object)(struct fscache_object *object); - - /* discard the resources pinned by an object and effect retirement if - * necessary */ - void (*drop_object)(struct fscache_object *object); - - /* dispose of a reference to an object */ - void (*put_object)(struct fscache_object *object); - - /* sync a cache */ - void (*sync_cache)(struct fscache_cache *cache); - - /* notification that the attributes of a non-index object (such as - * i_size) have changed */ - int (*attr_changed)(struct fscache_object *object); - - /* reserve space for an object's data and associated metadata */ - int (*reserve_space)(struct fscache_object *object, loff_t i_size); - - /* request a backing block for a page be read or allocated in the - * cache */ - fscache_page_retrieval_func_t read_or_alloc_page; - - /* request backing blocks for a list of pages be read or allocated in - * the cache */ - fscache_pages_retrieval_func_t read_or_alloc_pages; - - /* request a backing block for a page be allocated in the cache so that - * it can be written directly */ - fscache_page_retrieval_func_t allocate_page; - - /* request backing blocks for pages be allocated in the cache so that - * they can be written directly */ - fscache_pages_retrieval_func_t allocate_pages; - - /* write a page to its backing block in the cache */ - int (*write_page)(struct fscache_storage *op, struct page *page); - - /* detach backing block from a page (optional) - * - must release the cookie lock before returning - * - may sleep - */ - void (*uncache_page)(struct fscache_object *object, - struct page *page); - - /* dissociate a cache from all the pages it was backing */ - 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) */ -}; - -extern struct fscache_cookie fscache_fsdef_index; - -/* - * 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_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; - - int debug_id; /* debugging ID */ - int n_children; /* number of child objects */ - int n_ops; /* number of ops outstanding on object */ - int n_obj_ops; /* number of object ops outstanding on object */ - int n_in_progress; /* number of ops in progress */ - int n_exclusive; /* number of exclusive ops queued */ - atomic_t n_reads; /* number of read ops in progress */ - spinlock_t lock; /* state and operations lock */ - - unsigned long lookup_jif; /* time at which lookup started */ - 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) */ -#define FSCACHE_OBJECT_EV_REQUEUE 0 /* T if object should be requeued */ -#define FSCACHE_OBJECT_EV_UPDATE 1 /* T if object should be updated */ -#define FSCACHE_OBJECT_EV_CLEARED 2 /* T if accessors all gone */ -#define FSCACHE_OBJECT_EV_ERROR 3 /* T if fatal error occurred during processing */ -#define FSCACHE_OBJECT_EV_RELEASE 4 /* T if netfs requested object release */ -#define FSCACHE_OBJECT_EV_RETIRE 5 /* T if netfs requested object retirement */ -#define FSCACHE_OBJECT_EV_WITHDRAW 6 /* T if cache requested object withdrawal */ -#define FSCACHE_OBJECT_EVENTS_MASK 0x7f /* mask of all events*/ - - unsigned long flags; -#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 */ - - struct list_head cache_link; /* link in cache->object_list */ - struct hlist_node cookie_link; /* link in cookie->backing_objects */ - struct fscache_cache *cache; /* cache that supplied this object */ - struct fscache_cookie *cookie; /* netfs's file/index object */ - struct fscache_object *parent; /* parent object */ - struct work_struct work; /* attention scheduling record */ - struct list_head dependents; /* FIFO of dependent objects */ - struct list_head dep_link; /* link in parent's dependents list */ - struct list_head pending_ops; /* unstarted operations on this object */ -#ifdef CONFIG_FSCACHE_OBJECT_LIST - struct rb_node objlist_link; /* link in global object list */ -#endif - pgoff_t store_limit; /* current storage limit */ - loff_t store_limit_l; /* current storage limit */ -}; - -extern const char *fscache_object_states[]; - -#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_work_func(struct work_struct *work); - -/** - * 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; -} - -extern void fscache_object_lookup_negative(struct fscache_object *object); -extern void fscache_obtained_object(struct fscache_object *object); - -#ifdef CONFIG_FSCACHE_OBJECT_LIST -extern void fscache_object_destroy(struct fscache_object *object); -#else -#define fscache_object_destroy(object) do {} while(0) -#endif - -/** - * fscache_object_destroyed - Note destruction of an object in a cache - * @cache: The cache from which the object came - * - * Note the destruction and deallocation of an object record in a cache. - */ -static inline void fscache_object_destroyed(struct fscache_cache *cache) -{ - if (atomic_dec_and_test(&cache->object_count)) - wake_up_all(&fscache_cache_cleared_wq); -} - -/** - * fscache_object_lookup_error - Note an object encountered an error - * @object: The object on which the error was encountered - * - * Note that an object encountered a fatal error (usually an I/O error) and - * that it should be withdrawn as soon as possible. - */ -static inline void fscache_object_lookup_error(struct fscache_object *object) -{ - set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events); -} - -/** - * fscache_set_store_limit - Set the maximum size to be stored in an object - * @object: The object to set the maximum on - * @i_size: The limit to set in bytes - * - * Set the maximum size an object is permitted to reach, implying the highest - * byte that may be written. Intended to be called by the attr_changed() op. - * - * See Documentation/filesystems/caching/backend-api.txt for a complete - * description. - */ -static inline -void fscache_set_store_limit(struct fscache_object *object, loff_t i_size) -{ - object->store_limit_l = i_size; - object->store_limit = i_size >> PAGE_SHIFT; - if (i_size & ~PAGE_MASK) - object->store_limit++; -} - -/** - * fscache_end_io - End a retrieval operation on a page - * @op: The FS-Cache operation covering the retrieval - * @page: The page that was to be fetched - * @error: The error code (0 if successful) - * - * Note the end of an operation to retrieve a page, as covered by a particular - * operation record. - */ -static inline void fscache_end_io(struct fscache_retrieval *op, - struct page *page, int error) -{ - op->end_io_func(page, op->context, error); -} - -/* - * out-of-line cache backend functions - */ -extern __printf(3, 4) -void fscache_init_cache(struct fscache_cache *cache, - const struct fscache_cache_ops *ops, - const char *idfmt, ...); - -extern int fscache_add_cache(struct fscache_cache *cache, - struct fscache_object *fsdef, - const char *tagname); -extern void fscache_withdraw_cache(struct fscache_cache *cache); - -extern void fscache_io_error(struct fscache_cache *cache); - -extern void fscache_mark_pages_cached(struct fscache_retrieval *op, - struct pagevec *pagevec); - -extern bool fscache_object_sleep_till_congested(signed long *timeoutp); - -extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object, - const void *data, - uint16_t datalen); - -#endif /* _LINUX_FSCACHE_CACHE_H */ |