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/* SPDX-License-Identifier: GPL-2.0-or-later *//* General netfs cache on cache files internal defs * * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #ifdef pr_fmt#undef pr_fmt#endif #define pr_fmt(fmt) "CacheFiles: " fmt  #include <linux/fscache-cache.h>#include <linux/cred.h>#include <linux/security.h>#include <linux/xarray.h>#include <linux/cachefiles.h> #define CACHEFILES_DIO_BLOCK_SIZE 4096 struct cachefiles_cache;struct cachefiles_object; enum cachefiles_content {	/* These values are saved on disk */	CACHEFILES_CONTENT_NO_DATA	= 0, /* No content stored */	CACHEFILES_CONTENT_SINGLE	= 1, /* Content is monolithic, all is present */	CACHEFILES_CONTENT_ALL		= 2, /* Content is all present, no map */	CACHEFILES_CONTENT_BACKFS_MAP	= 3, /* Content is piecemeal, mapped through backing fs */	CACHEFILES_CONTENT_DIRTY	= 4, /* Content is dirty (only seen on disk) */	nr__cachefiles_content}; /* * Cached volume representation. */struct cachefiles_volume {	struct cachefiles_cache		*cache;	struct list_head		cache_link;	/* Link in cache->volumes */	struct fscache_volume		*vcookie;	/* The netfs's representation */	struct dentry			*dentry;	/* The volume dentry */	struct dentry			*fanout[256];	/* Fanout subdirs */}; enum cachefiles_object_state {	CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */	CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */	CACHEFILES_ONDEMAND_OBJSTATE_REOPENING, /* Object that was closed and is being reopened. */	CACHEFILES_ONDEMAND_OBJSTATE_DROPPING, /* Object is being dropped. */}; struct cachefiles_ondemand_info {	struct work_struct		ondemand_work;	int				ondemand_id;	enum cachefiles_object_state	state;	struct cachefiles_object	*object;	spinlock_t			lock;}; /* * Backing file state. */struct cachefiles_object {	struct fscache_cookie		*cookie;	/* Netfs data storage object cookie */	struct cachefiles_volume	*volume;	/* Cache volume that holds this object */	struct list_head		cache_link;	/* Link in cache->*_list */	struct file			*file;		/* The file representing this object */	char				*d_name;	/* Backing file name */	int				debug_id;	spinlock_t			lock;	refcount_t			ref;	enum cachefiles_content		content_info:8;	/* Info about content presence */	unsigned long			flags;#define CACHEFILES_OBJECT_USING_TMPFILE	0		/* Have an unlinked tmpfile */#ifdef CONFIG_CACHEFILES_ONDEMAND	struct cachefiles_ondemand_info	*ondemand;#endif}; #define CACHEFILES_ONDEMAND_ID_CLOSED	-1 /* * Cache files cache definition */struct cachefiles_cache {	struct fscache_cache		*cache;		/* Cache cookie */	struct vfsmount			*mnt;		/* mountpoint holding the cache */	struct dentry			*store;		/* Directory into which live objects go */	struct dentry			*graveyard;	/* directory into which dead objects go */	struct file			*cachefilesd;	/* manager daemon handle */	struct list_head		volumes;	/* List of volume objects */	struct list_head		object_list;	/* List of active objects */	spinlock_t			object_list_lock; /* Lock for volumes and object_list */	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 */	atomic_t			gravecounter;	/* graveyard uniquifier */	atomic_t			f_released;	/* number of objects released lately */	atomic_long_t			b_released;	/* number of blocks released lately */	atomic_long_t			b_writing;	/* Number of blocks being written */	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;		/* ilog2(bsize) */	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) */#define CACHEFILES_ONDEMAND_MODE	4	/* T if in on-demand read mode */	char				*rootdirname;	/* name of cache root directory */	char				*tag;		/* cache binding tag */	refcount_t			unbind_pincount;/* refcount to do daemon unbind */	struct xarray			reqs;		/* xarray of pending on-demand requests */	unsigned long			req_id_next;	struct xarray			ondemand_ids;	/* xarray for ondemand_id allocation */	u32				ondemand_id_next;	u32				msg_id_next;	u32				secid;		/* LSM security id */	bool				have_secid;	/* whether "secid" was set */}; static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache){	return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&		test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);} struct cachefiles_req {	struct cachefiles_object *object;	struct completion done;	refcount_t ref;	int error;	struct cachefiles_msg msg;}; #define CACHEFILES_REQ_NEW	XA_MARK_1 #include <trace/events/cachefiles.h> static inlinestruct file *cachefiles_cres_file(struct netfs_cache_resources *cres){	return cres->cache_priv2;} static inlinestruct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres){	return fscache_cres_cookie(cres)->cache_priv;} /* * 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);} /* * cache.c */extern int cachefiles_add_cache(struct cachefiles_cache *cache);extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); enum cachefiles_has_space_for {	cachefiles_has_space_check,	cachefiles_has_space_for_write,	cachefiles_has_space_for_create,};extern int cachefiles_has_space(struct cachefiles_cache *cache,				unsigned fnr, unsigned bnr,				enum cachefiles_has_space_for reason); /* * daemon.c */extern const struct file_operations cachefiles_daemon_fops;extern void cachefiles_flush_reqs(struct cachefiles_cache *cache);extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache); /* * error_inject.c */#ifdef CONFIG_CACHEFILES_ERROR_INJECTIONextern unsigned int cachefiles_error_injection_state;extern int cachefiles_register_error_injection(void);extern void cachefiles_unregister_error_injection(void); #else#define cachefiles_error_injection_state 0 static inline int cachefiles_register_error_injection(void){	return 0;} static inline void cachefiles_unregister_error_injection(void){}#endif  static inline int cachefiles_inject_read_error(void){	return cachefiles_error_injection_state & 2 ? -EIO : 0;} static inline int cachefiles_inject_write_error(void){	return cachefiles_error_injection_state & 2 ? -EIO :		cachefiles_error_injection_state & 1 ? -ENOSPC :		0;} static inline int cachefiles_inject_remove_error(void){	return cachefiles_error_injection_state & 2 ? -EIO : 0;} /* * interface.c */extern const struct fscache_cache_ops cachefiles_cache_ops;extern void cachefiles_see_object(struct cachefiles_object *object,				  enum cachefiles_obj_ref_trace why);extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,							enum cachefiles_obj_ref_trace why);extern void cachefiles_put_object(struct cachefiles_object *object,				  enum cachefiles_obj_ref_trace why); /* * io.c */extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,				       enum fscache_want_state want_state);extern int __cachefiles_prepare_write(struct cachefiles_object *object,				      struct file *file,				      loff_t *_start, size_t *_len, size_t upper_len,				      bool no_space_allocated_yet);extern int __cachefiles_write(struct cachefiles_object *object,			      struct file *file,			      loff_t start_pos,			      struct iov_iter *iter,			      netfs_io_terminated_t term_func,			      void *term_func_priv); /* * key.c */extern bool cachefiles_cook_key(struct cachefiles_object *object); /* * main.c */extern struct kmem_cache *cachefiles_object_jar; /* * namei.c */extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,					   struct file *file);extern int cachefiles_bury_object(struct cachefiles_cache *cache,				  struct cachefiles_object *object,				  struct dentry *dir,				  struct dentry *rep,				  enum fscache_why_object_killed why);extern int cachefiles_delete_object(struct cachefiles_object *object,				    enum fscache_why_object_killed why);extern bool cachefiles_look_up_object(struct cachefiles_object *object);extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,					       struct dentry *dir,					       const char *name,					       bool *_is_new);extern void cachefiles_put_directory(struct dentry *dir); 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);extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,				      struct cachefiles_object *object); /* * ondemand.c */#ifdef CONFIG_CACHEFILES_ONDEMANDextern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,					char __user *_buffer, size_t buflen); extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,				     char *args); extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache,					char *args); extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object); extern int cachefiles_ondemand_read(struct cachefiles_object *object,				    loff_t pos, size_t len); extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,					struct cachefiles_volume *volume);extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj); #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE)	\static inline bool								\cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \{												\	return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \}												\												\static inline void								\cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \{												\	object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \} CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING); static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req){	return cachefiles_ondemand_object_is_reopening(req->object) &&			req->msg.opcode == CACHEFILES_OP_READ;} #elsestatic inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,					char __user *_buffer, size_t buflen){	return -EOPNOTSUPP;} static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object){	return 0;} static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object){} static inline int cachefiles_ondemand_read(struct cachefiles_object *object,					   loff_t pos, size_t len){	return -EOPNOTSUPP;} static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,						struct cachefiles_volume *volume){	return 0;}static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj){} static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req){	return false;}#endif /* * 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);} /* * volume.c */void cachefiles_acquire_volume(struct fscache_volume *volume);void cachefiles_free_volume(struct fscache_volume *volume);void cachefiles_withdraw_volume(struct cachefiles_volume *volume); /* * xattr.c */extern int cachefiles_set_object_xattr(struct cachefiles_object *object);extern int cachefiles_check_auxdata(struct cachefiles_object *object,				    struct file *file);extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,					  struct cachefiles_object *object,					  struct dentry *dentry);extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); /* * Error handling */#define cachefiles_io_error(___cache, FMT, ...)		\do {							\	pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);	\	fscache_io_error((___cache)->cache);		\	set_bit(CACHEFILES_DEAD, &(___cache)->flags);	\	if (cachefiles_in_ondemand_mode(___cache))	\		cachefiles_flush_reqs(___cache);	\} while (0) #define cachefiles_io_error_obj(object, FMT, ...)			\do {									\	struct cachefiles_cache *___cache;				\									\	___cache = (object)->volume->cache;				\	cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__,	\			    (object)->debug_id);			\} while (0)  /* * Debug tracing */extern unsigned cachefiles_debug;#define CACHEFILES_DEBUG_KENTER	1#define CACHEFILES_DEBUG_KLEAVE	2#define CACHEFILES_DEBUG_KDEBUG	4 #define dbgprintk(FMT, ...) \	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) #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, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)#endif #if 1 /* defined(__KDEBUGALL) */ #define ASSERT(X)							\do {									\	if (unlikely(!(X))) {						\		pr_err("\n");						\		pr_err("Assertion failed\n");		\		BUG();							\

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