Define structures to represent the state inside cachefiles. There are
three structures:
(1) struct cachefiles_cache.
This represents the cache as a whole and is used to keep track of the
cache parameters and security, the communication channel to the
controlling daemon and various directories in the cache filesystem.
(2) struct cachefiles_volume.
This represents a volume in the cache. It keeps track of the
directory for the volume and the fanout subdirs that form a hash
table.
(3) struct cachefiles_object.
This represents a data file in the cache. It keeps track of the
filename and the open file handle for the relevant file.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-cachefs@xxxxxxxxxx
---
fs/cachefiles/internal.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 86 insertions(+)
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 2f8e2835a785..11dcf9dbcf05 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -19,11 +19,97 @@
#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
+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 */
+};
+
+/*
+ * node records
+ */
+struct cachefiles_object {
+ int debug_id; /* debugging ID */
+ spinlock_t lock; /* state and operations lock */
+
+ struct list_head cache_link; /* Link in cache->*_list */
+ struct cachefiles_volume *volume; /* Cache volume that holds this object */
+ struct fscache_cookie *cookie; /* netfs's file/index object */
+ struct file *file; /* The file representing this object */
+ char *d_name; /* Filename */
+ atomic_t usage; /* object usage count */
+ u8 d_name_len; /* Length of filename */
+ u8 key_hash; /* Hash of object key */
+ unsigned long flags;
+#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */
+ enum cachefiles_content content_info:8; /* Info about content presence */
+};
+
+/*
+ * 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;
+ 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 */
+ 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 */
+};
+
/*
* error_inject.c
*/
