/* General netfs cache on cache files internal defs * * Copyright (C) 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 Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #include <linux/fscache-cache.h> #include <linux/timer.h> #include <linux/wait.h> #include <linux/workqueue.h> #include <linux/security.h> struct cachefiles_cache; struct cachefiles_object; extern unsigned cachefiles_debug; #define CACHEFILES_DEBUG_KENTER 1 #define CACHEFILES_DEBUG_KLEAVE 2 #define CACHEFILES_DEBUG_KDEBUG 4 /* * node records */ struct cachefiles_object { struct fscache_object fscache; /* fscache handle */ struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ struct dentry *dentry; /* the file/dir representing this object */ struct dentry *backer; /* backing file */ loff_t i_size; /* object size */ unsigned long flags; #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ #define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */ atomic_t usage; /* object usage count */ uint8_t type; /* object type */ uint8_t new; /* T if object new */ spinlock_t work_lock; struct rb_node active_node; /* link in active tree (dentry is key) */ }; extern struct kmem_cache *cachefiles_object_jar; /* * Cache files cache definition */ struct cachefiles_cache { struct fscache_cache cache; /* FS-Cache record */ struct vfsmount *mnt; /* mountpoint holding the cache */ struct dentry *graveyard; /* directory into which dead objects go */ struct file *cachefilesd; /* manager daemon handle */ const struct cred *cache_cred; /* security override for accessing cache */ struct mutex daemon_mutex; /* command serialisation mutex */ wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ struct rb_root active_nodes; /* active nodes (can't be culled) */ rwlock_t active_lock; /* lock for active_nodes */ atomic_t gravecounter; /* graveyard uniquifier */ unsigned frun_percent; /* when to stop culling (% files) */ unsigned fcull_percent; /* when to start culling (% files) */ unsigned fstop_percent; /* when to stop allocating (% files) */ unsigned brun_percent; /* when to stop culling (% blocks) */ unsigned bcull_percent; /* when to start culling (% blocks) */ unsigned bstop_percent; /* when to stop allocating (% blocks) */ unsigned bsize; /* cache's block size */ unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ uint64_t frun; /* when to stop culling */ uint64_t fcull; /* when to start culling */ uint64_t fstop; /* when to stop allocating */ sector_t brun; /* when to stop culling */ sector_t bcull; /* when to start culling */ sector_t bstop; /* when to stop allocating */ unsigned long flags; #define CACHEFILES_READY 0 /* T if cache prepared */ #define CACHEFILES_DEAD 1 /* T if cache dead */ #define CACHEFILES_CULLING 2 /* T if cull engaged */ #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ char *rootdirname; /* name of cache root directory */ char *secctx; /* LSM security context */ char *tag; /* cache binding tag */ }; /* * backing file read tracking */ struct cachefiles_one_read { wait_queue_t monitor; /* link into monitored waitqueue */ struct page *back_page; /* backing file page we're waiting for */ struct page *netfs_page; /* netfs page we're going to fill */ struct fscache_retrieval *op; /* retrieval op covering this */ struct list_head op_link; /* link in op's todo list */ }; /* * backing file write tracking */ struct cachefiles_one_write { struct page *netfs_page; /* netfs page to copy */ struct cachefiles_object *object; struct list_head obj_link; /* link in object's lists */ fscache_rw_complete_t end_io_func; void *context; }; /* * auxiliary data xattr buffer */ struct cachefiles_xattr { uint16_t len; uint8_t type; uint8_t data[]; }; /* * note change of state for daemon */ static inline void cachefiles_state_changed(struct cachefiles_cache *cache) { set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); wake_up_all(&cache->daemon_pollwq); } /* * bind.c */ extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); /* * daemon.c */ extern const struct file_operations cachefiles_daemon_fops; extern int cachefiles_has_space(struct cachefiles_cache *cache, unsigned fnr, unsigned bnr); /* * interface.c */ extern const struct fscache_cache_ops cachefiles_cache_ops; /* * key.c */ extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); /* * namei.c */ extern int cachefiles_delete_object(struct cachefiles_cache *cache, struct cachefiles_object *object); extern int cachefiles_walk_to_object(struct cachefiles_object *parent, struct cachefiles_object *object, const char *key, struct cachefiles_xattr *auxdata); extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, struct dentry *dir, const char *name); extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, char *filename); extern int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, char *filename); /* * proc.c */ #ifdef CONFIG_CACHEFILES_HISTOGRAM extern atomic_t cachefiles_lookup_histogram[HZ]; extern atomic_t cachefiles_mkdir_histogram[HZ]; extern atomic_t cachefiles_create_histogram[HZ]; extern int __init cachefiles_proc_init(void); extern void cachefiles_proc_cleanup(void); static inline void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) { unsigned long jif = jiffies - start_jif; if (jif >= HZ) jif = HZ - 1; atomic_inc(&histogram[jif]); } #else #define cachefiles_proc_init() (0) #define cachefiles_proc_cleanup() do {} while (0) #define cachefiles_hist(hist, start_jif) do {} while (0) #endif /* * rdwr.c */ extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, struct page *, gfp_t); extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, struct list_head *, unsigned *, gfp_t); extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, gfp_t); extern int cachefiles_allocate_pages(struct fscache_retrieval *, struct list_head *, unsigned *, gfp_t); extern int cachefiles_write_page(struct fscache_storage *, struct page *); extern void cachefiles_uncache_page(struct fscache_object *, struct page *); /* * security.c */ extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, struct dentry *root, const struct cred **_saved_cred); static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, const struct cred **_saved_cred) { *_saved_cred = override_creds(cache->cache_cred); } static inline void cachefiles_end_secure(struct cachefiles_cache *cache, const struct cred *saved_cred) { revert_creds(saved_cred); } /* * xattr.c */ extern int cachefiles_check_object_type(struct cachefiles_object *object); extern int cachefiles_set_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); extern int cachefiles_update_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); extern int cachefiles_check_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, struct dentry *dentry); /* * error handling */ #define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__) #define cachefiles_io_error(___cache, FMT, ...) \ do { \ kerror("I/O Error: " FMT, ##__VA_ARGS__); \ fscache_io_error(&(___cache)->cache); \ set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ } while (0) #define cachefiles_io_error_obj(object, FMT, ...) \ do { \ struct cachefiles_cache *___cache; \ \ ___cache = container_of((object)->fscache.cache, \ struct cachefiles_cache, cache); \ cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ } while (0) /* * debug tracing */ #define dbgprintk(FMT, ...) \ printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) /* make sure we maintain the format strings, even when debugging is disabled */ static inline void _dbprintk(const char *fmt, ...) __attribute__((format(printf, 1, 2))); static inline void _dbprintk(const char *fmt, ...) { } #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) #if defined(__KDEBUG) #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) #elif defined(CONFIG_CACHEFILES_DEBUG) #define _enter(FMT, ...) \ do { \ if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ kenter(FMT, ##__VA_ARGS__); \ } while (0) #define _leave(FMT, ...) \ do { \ if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ kleave(FMT, ##__VA_ARGS__); \ } while (0) #define _debug(FMT, ...) \ do { \ if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ kdebug(FMT, ##__VA_ARGS__); \ } while (0) #else #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__) #endif #if 1 /* defined(__KDEBUGALL) */ #define ASSERT(X) \ do { \ if (unlikely(!(X))) { \ printk(KERN_ERR "\n"); \ printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ BUG(); \ } \ } while (0) #define ASSERTCMP(X, OP, Y) \ do { \ if (unlikely(!((X) OP (Y)))) { \ printk(KERN_ERR "\n"); \ printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ printk(KERN_ERR "%lx " #OP " %lx is false\n", \ (unsigned long)(X), (unsigned long)(Y)); \ BUG(); \ } \ } while (0) #define ASSERTIF(C, X) \ do { \ if (unlikely((C) && !(X))) { \ printk(KERN_ERR "\n"); \ printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ BUG(); \ } \ } while (0) #define ASSERTIFCMP(C, X, OP, Y) \ do { \ if (unlikely((C) && !((X) OP (Y)))) { \ printk(KERN_ERR "\n"); \ printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ printk(KERN_ERR "%lx " #OP " %lx is false\n", \ (unsigned long)(X), (unsigned long)(Y)); \ BUG(); \ } \ } while (0) #else #define ASSERT(X) do {} while (0) #define ASSERTCMP(X, OP, Y) do {} while (0) #define ASSERTIF(C, X) do {} while (0) #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) #endif