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authorLinus Torvalds <torvalds@linux-foundation.org>2009-04-03 10:07:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-03 10:07:43 -0700
commit3cc50ac0dbda5100684e570247782330155d35e0 (patch)
treef4b8f22d1725ebe65d2fe658d292dabacd7ed564 /include
parentd9b9be024a6628a01d8730d1fd0b5f25658a2794 (diff)
parentb797cac7487dee6bfddeb161631c1bbc54fa3cdb (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache: (41 commits) NFS: Add mount options to enable local caching on NFS NFS: Display local caching state NFS: Store pages from an NFS inode into a local cache NFS: Read pages from FS-Cache into an NFS inode NFS: nfs_readpage_async() needs to be accessible as a fallback for local caching NFS: Add read context retention for FS-Cache to call back with NFS: FS-Cache page management NFS: Add some new I/O counters for FS-Cache doing things for NFS NFS: Invalidate FsCache page flags when cache removed NFS: Use local disk inode cache NFS: Define and create inode-level cache objects NFS: Define and create superblock-level objects NFS: Define and create server-level objects NFS: Register NFS for caching and retrieve the top-level index NFS: Permit local filesystem caching to be enabled for NFS NFS: Add FS-Cache option bit and debug bit NFS: Add comment banners to some NFS functions FS-Cache: Make kAFS use FS-Cache CacheFiles: A cache that backs onto a mounted filesystem CacheFiles: Export things for CacheFiles ...
Diffstat (limited to 'include')
-rw-r--r--include/linux/fscache-cache.h505
-rw-r--r--include/linux/fscache.h618
-rw-r--r--include/linux/nfs_fs.h13
-rw-r--r--include/linux/nfs_fs_sb.h11
-rw-r--r--include/linux/nfs_iostat.h12
-rw-r--r--include/linux/page-flags.h40
-rw-r--r--include/linux/pagemap.h5
-rw-r--r--include/linux/slow-work.h95
8 files changed, 1293 insertions, 6 deletions
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
new file mode 100644
index 00000000000..84d3532dd3e
--- /dev/null
+++ b/include/linux/fscache-cache.h
@@ -0,0 +1,505 @@
+/* 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/slow-work.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 {
+ union {
+ struct work_struct fast_work; /* record for fast ops */
+ struct slow_work slow_work; /* record for (very) slow 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_FAST 0x0001 /* - fast op, processor may not sleep for disk */
+#define FSCACHE_OP_SLOW 0x0002 /* - (very) slow op, processor may sleep for disk */
+#define FSCACHE_OP_MYTHREAD 0x0003 /* - 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 */
+
+ 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 const struct slow_work_ops fscache_op_slow_work_ops;
+
+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, either fast_work or slow_work if necessary, and processor if needed.
+ */
+static inline void fscache_operation_init(struct fscache_operation *op,
+ fscache_operation_release_t release)
+{
+ atomic_set(&op->usage, 1);
+ op->debug_id = atomic_inc_return(&fscache_op_debug_id);
+ op->release = release;
+ INIT_LIST_HEAD(&op->pend_link);
+}
+
+/**
+ * fscache_operation_init_slow - Do additional initialisation of a slow op
+ * @op: The operation to initialise
+ * @processor: The processor function to assign
+ *
+ * Do additional initialisation of an operation as required for slow work.
+ */
+static inline
+void fscache_operation_init_slow(struct fscache_operation *op,
+ fscache_operation_processor_t processor)
+{
+ op->processor = processor;
+ slow_work_init(&op->slow_work, &fscache_op_slow_work_ops);
+}
+
+/*
+ * 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 */
+ void (*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 auxilliary 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;
+ 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 */
+
+ 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 */
+ } 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 */
+ 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 */
+
+ 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 slow_work 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 */
+ pgoff_t store_limit; /* 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)
+
+extern const struct slow_work_ops fscache_object_slow_work_ops;
+
+/**
+ * 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);
+ vslow_work_init(&object->work, &fscache_object_slow_work_ops);
+ 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->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);
+
+/**
+ * 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 = 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 void fscache_init_cache(struct fscache_cache *cache,
+ const struct fscache_cache_ops *ops,
+ const char *idfmt,
+ ...) __attribute__ ((format (printf, 3, 4)));
+
+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 enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
+ const void *data,
+ uint16_t datalen);
+
+#endif /* _LINUX_FSCACHE_CACHE_H */
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
new file mode 100644
index 00000000000..6d8ee466e0a
--- /dev/null
+++ b/include/linux/fscache.h
@@ -0,0 +1,618 @@
+/* General filesystem caching 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/netfs-api.txt
+ *
+ * for a description of the network filesystem interface declared here.
+ */
+
+#ifndef _LINUX_FSCACHE_H
+#define _LINUX_FSCACHE_H
+
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+
+#if defined(CONFIG_FSCACHE) || defined(CONFIG_FSCACHE_MODULE)
+#define fscache_available() (1)
+#define fscache_cookie_valid(cookie) (cookie)
+#else
+#define fscache_available() (0)
+#define fscache_cookie_valid(cookie) (0)
+#endif
+
+
+/*
+ * overload PG_private_2 to give us PG_fscache - this is used to indicate that
+ * a page is currently backed by a local disk cache
+ */
+#define PageFsCache(page) PagePrivate2((page))
+#define SetPageFsCache(page) SetPagePrivate2((page))
+#define ClearPageFsCache(page) ClearPagePrivate2((page))
+#define TestSetPageFsCache(page) TestSetPagePrivate2((page))
+#define TestClearPageFsCache(page) TestClearPagePrivate2((page))
+
+/* pattern used to fill dead space in an index entry */
+#define FSCACHE_INDEX_DEADFILL_PATTERN 0x79
+
+struct pagevec;
+struct fscache_cache_tag;
+struct fscache_cookie;
+struct fscache_netfs;
+
+typedef void (*fscache_rw_complete_t)(struct page *page,
+ void *context,
+ int error);
+
+/* result of index entry consultation */
+enum fscache_checkaux {
+ FSCACHE_CHECKAUX_OKAY, /* entry okay as is */
+ FSCACHE_CHECKAUX_NEEDS_UPDATE, /* entry requires update */
+ FSCACHE_CHECKAUX_OBSOLETE, /* entry requires deletion */
+};
+
+/*
+ * fscache cookie definition
+ */
+struct fscache_cookie_def {
+ /* name of cookie type */
+ char name[16];
+
+ /* cookie type */
+ uint8_t type;
+#define FSCACHE_COOKIE_TYPE_INDEX 0
+#define FSCACHE_COOKIE_TYPE_DATAFILE 1
+
+ /* select the cache into which to insert an entry in this index
+ * - optional
+ * - should return a cache identifier or NULL to cause the cache to be
+ * inherited from the parent if possible or the first cache picked
+ * for a non-index file if not
+ */
+ struct fscache_cache_tag *(*select_cache)(
+ const void *parent_netfs_data,
+ const void *cookie_netfs_data);
+
+ /* get an index key
+ * - should store the key data in the buffer
+ * - should return the amount of amount stored
+ * - not permitted to return an error
+ * - the netfs data from the cookie being used as the source is
+ * presented
+ */
+ uint16_t (*get_key)(const void *cookie_netfs_data,
+ void *buffer,
+ uint16_t bufmax);
+
+ /* get certain file attributes from the netfs data
+ * - this function can be absent for an index
+ * - not permitted to return an error
+ * - the netfs data from the cookie being used as the source is
+ * presented
+ */
+ void (*get_attr)(const void *cookie_netfs_data, uint64_t *size);
+
+ /* get the auxilliary data from netfs data
+ * - this function can be absent if the index carries no state data
+ * - should store the auxilliary data in the buffer
+ * - should return the amount of amount stored
+ * - not permitted to return an error
+ * - the netfs data from the cookie being used as the source is
+ * presented
+ */
+ uint16_t (*get_aux)(const void *cookie_netfs_data,
+ void *buffer,
+ uint16_t bufmax);
+
+ /* consult the netfs about the state of an object
+ * - this function can be absent if the index carries no state data
+ * - the netfs data from the cookie being used as the target is
+ * presented, as is the auxilliary data
+ */
+ enum fscache_checkaux (*check_aux)(void *cookie_netfs_data,
+ const void *data,
+ uint16_t datalen);
+
+ /* get an extra reference on a read context
+ * - this function can be absent if the completion function doesn't
+ * require a context
+ */
+ void (*get_context)(void *cookie_netfs_data, void *context);
+
+ /* release an extra reference on a read context
+ * - this function can be absent if the completion function doesn't
+ * require a context
+ */
+ void (*put_context)(void *cookie_netfs_data, void *context);
+
+ /* indicate pages that now have cache metadata retained
+ * - this function should mark the specified pages as now being cached
+ * - the pages will have been marked with PG_fscache before this is
+ * called, so this is optional
+ */
+ void (*mark_pages_cached)(void *cookie_netfs_data,
+ struct address_space *mapping,
+ struct pagevec *cached_pvec);
+
+ /* indicate the cookie is no longer cached
+ * - this function is called when the backing store currently caching
+ * a cookie is removed
+ * - the netfs should use this to clean up any markers indicating
+ * cached pages
+ * - this is mandatory for any object that may have data
+ */
+ void (*now_uncached)(void *cookie_netfs_data);
+};
+
+/*
+ * fscache cached network filesystem type
+ * - name, version and ops must be filled in before registration
+ * - all other fields will be set during registration
+ */
+struct fscache_netfs {
+ uint32_t version; /* indexing version */
+ const char *name; /* filesystem name */
+ struct fscache_cookie *primary_index;
+ struct list_head link; /* internal link */
+};
+
+/*
+ * slow-path functions for when there is actually caching available, and the
+ * netfs does actually have a valid token
+ * - these are not to be called directly
+ * - these are undefined symbols when FS-Cache is not configured and the
+ * optimiser takes care of not using them
+ */
+extern int __fscache_register_netfs(struct fscache_netfs *);
+extern void __fscache_unregister_netfs(struct fscache_netfs *);
+extern struct fscache_cache_tag *__fscache_lookup_cache_tag(const char *);
+extern void __fscache_release_cache_tag(struct fscache_cache_tag *);
+
+extern struct fscache_cookie *__fscache_acquire_cookie(
+ struct fscache_cookie *,
+ const struct fscache_cookie_def *,
+ void *);
+extern void __fscache_relinquish_cookie(struct fscache_cookie *, int);
+extern void __fscache_update_cookie(struct fscache_cookie *);
+extern int __fscache_attr_changed(struct fscache_cookie *);
+extern int __fscache_read_or_alloc_page(struct fscache_cookie *,
+ struct page *,
+ fscache_rw_complete_t,
+ void *,
+ gfp_t);
+extern int __fscache_read_or_alloc_pages(struct fscache_cookie *,
+ struct address_space *,
+ struct list_head *,
+ unsigned *,
+ fscache_rw_complete_t,
+ void *,
+ gfp_t);
+extern int __fscache_alloc_page(struct fscache_cookie *, struct page *, gfp_t);
+extern int __fscache_write_page(struct fscache_cookie *, struct page *, gfp_t);
+extern void __fscache_uncache_page(struct fscache_cookie *, struct page *);
+extern bool __fscache_check_page_write(struct fscache_cookie *, struct page *);
+extern void __fscache_wait_on_page_write(struct fscache_cookie *, struct page *);
+
+/**
+ * fscache_register_netfs - Register a filesystem as desiring caching services
+ * @netfs: The description of the filesystem
+ *
+ * Register a filesystem as desiring caching services if they're available.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_register_netfs(struct fscache_netfs *netfs)
+{
+ if (fscache_available())
+ return __fscache_register_netfs(netfs);
+ else
+ return 0;
+}
+
+/**
+ * fscache_unregister_netfs - Indicate that a filesystem no longer desires
+ * caching services
+ * @netfs: The description of the filesystem
+ *
+ * Indicate that a filesystem no longer desires caching services for the
+ * moment.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_unregister_netfs(struct fscache_netfs *netfs)
+{
+ if (fscache_available())
+ __fscache_unregister_netfs(netfs);
+}
+
+/**
+ * fscache_lookup_cache_tag - Look up a cache tag
+ * @name: The name of the tag to search for
+ *
+ * Acquire a specific cache referral tag that can be used to select a specific
+ * cache in which to cache an index.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+struct fscache_cache_tag *fscache_lookup_cache_tag(const char *name)
+{
+ if (fscache_available())
+ return __fscache_lookup_cache_tag(name);
+ else
+ return NULL;
+}
+
+/**
+ * fscache_release_cache_tag - Release a cache tag
+ * @tag: The tag to release
+ *
+ * Release a reference to a cache referral tag previously looked up.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_release_cache_tag(struct fscache_cache_tag *tag)
+{
+ if (fscache_available())
+ __fscache_release_cache_tag(tag);
+}
+
+/**
+ * fscache_acquire_cookie - Acquire a cookie to represent a cache object
+ * @parent: The cookie that's to be the parent of this one
+ * @def: A description of the cache object, including callback operations
+ * @netfs_data: An arbitrary piece of data to be kept in the cookie to
+ * represent the cache object to the netfs
+ *
+ * This function is used to inform FS-Cache about part of an index hierarchy
+ * that can be used to locate files. This is done by requesting a cookie for
+ * each index in the path to the file.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+struct fscache_cookie *fscache_acquire_cookie(
+ struct fscache_cookie *parent,
+ const struct fscache_cookie_def *def,
+ void *netfs_data)
+{
+ if (fscache_cookie_valid(parent))
+ return __fscache_acquire_cookie(parent, def, netfs_data);
+ else
+ return NULL;
+}
+
+/**
+ * fscache_relinquish_cookie - Return the cookie to the cache, maybe discarding
+ * it
+ * @cookie: The cookie being returned
+ * @retire: True if the cache object the cookie represents is to be discarded
+ *
+ * This function returns a cookie to the cache, forcibly discarding the
+ * associated cache object if retire is set to true.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
+{
+ if (fscache_cookie_valid(cookie))
+ __fscache_relinquish_cookie(cookie, retire);
+}
+
+/**
+ * fscache_update_cookie - Request that a cache object be updated
+ * @cookie: The cookie representing the cache object
+ *
+ * Request an update of the index data for the cache object associated with the
+ * cookie.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_update_cookie(struct fscache_cookie *cookie)
+{
+ if (fscache_cookie_valid(cookie))
+ __fscache_update_cookie(cookie);
+}
+
+/**
+ * fscache_pin_cookie - Pin a data-storage cache object in its cache
+ * @cookie: The cookie representing the cache object
+ *
+ * Permit data-storage cache objects to be pinned in the cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_pin_cookie(struct fscache_cookie *cookie)
+{
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_pin_cookie - Unpin a data-storage cache object in its cache
+ * @cookie: The cookie representing the cache object
+ *
+ * Permit data-storage cache objects to be unpinned from the cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_unpin_cookie(struct fscache_cookie *cookie)
+{
+}
+
+/**
+ * fscache_attr_changed - Notify cache that an object's attributes changed
+ * @cookie: The cookie representing the cache object
+ *
+ * Send a notification to the cache indicating that an object's attributes have
+ * changed. This includes the data size. These attributes will be obtained
+ * through the get_attr() cookie definition op.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_attr_changed(struct fscache_cookie *cookie)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_attr_changed(cookie);
+ else
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_reserve_space - Reserve data space for a cached object
+ * @cookie: The cookie representing the cache object
+ * @i_size: The amount of space to be reserved
+ *
+ * Reserve an amount of space in the cache for the cache object attached to a
+ * cookie so that a write to that object within the space can always be
+ * honoured.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_reserve_space(struct fscache_cookie *cookie, loff_t size)
+{
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_read_or_alloc_page - Read a page from the cache or allocate a block
+ * in which to store it
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page to fill if possible
+ * @end_io_func: The callback to invoke when and if the page is filled
+ * @context: An arbitrary piece of data to pass on to end_io_func()
+ * @gfp: The conditions under which memory allocation should be made
+ *
+ * Read a page from the cache, or if that's not possible make a potential
+ * one-block reservation in the cache into which the page may be stored once
+ * fetched from the server.
+ *
+ * If the page is not backed by the cache object, or if it there's some reason
+ * it can't be, -ENOBUFS will be returned and nothing more will be done for
+ * that page.
+ *
+ * Else, if that page is backed by the cache, a read will be initiated directly
+ * to the netfs's page and 0 will be returned by this function. The
+ * end_io_func() callback will be invoked when the operation terminates on a
+ * completion or failure. Note that the callback may be invoked before the
+ * return.
+ *
+ * Else, if the page is unbacked, -ENODATA is returned and a block may have
+ * been allocated in the cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_read_or_alloc_page(struct fscache_cookie *cookie,
+ struct page *page,
+ fscache_rw_complete_t end_io_func,
+ void *context,
+ gfp_t gfp)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_read_or_alloc_page(cookie, page, end_io_func,
+ context, gfp);
+ else
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_read_or_alloc_pages - Read pages from the cache and/or allocate
+ * blocks in which to store them
+ * @cookie: The cookie representing the cache object
+ * @mapping: The netfs inode mapping to which the pages will be attached
+ * @pages: A list of potential netfs pages to be filled
+ * @end_io_func: The callback to invoke when and if each page is filled
+ * @context: An arbitrary piece of data to pass on to end_io_func()
+ * @gfp: The conditions under which memory allocation should be made
+ *
+ * Read a set of pages from the cache, or if that's not possible, attempt to
+ * make a potential one-block reservation for each page in the cache into which
+ * that page may be stored once fetched from the server.
+ *
+ * If some pages are not backed by the cache object, or if it there's some
+ * reason they can't be, -ENOBUFS will be returned and nothing more will be
+ * done for that pages.
+ *
+ * Else, if some of the pages are backed by the cache, a read will be initiated
+ * directly to the netfs's page and 0 will be returned by this function. The
+ * end_io_func() callback will be invoked when the operation terminates on a
+ * completion or failure. Note that the callback may be invoked before the
+ * return.
+ *
+ * Else, if a page is unbacked, -ENODATA is returned and a block may have
+ * been allocated in the cache.
+ *
+ * Because the function may want to return all of -ENOBUFS, -ENODATA and 0 in
+ * regard to different pages, the return values are prioritised in that order.
+ * Any pages submitted for reading are removed from the pages list.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned *nr_pages,
+ fscache_rw_complete_t end_io_func,
+ void *context,
+ gfp_t gfp)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_read_or_alloc_pages(cookie, mapping, pages,
+ nr_pages, end_io_func,
+ context, gfp);
+ else
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_alloc_page - Allocate a block in which to store a page
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page to allocate a page for
+ * @gfp: The conditions under which memory allocation should be made
+ *
+ * Request Allocation a block in the cache in which to store a netfs page
+ * without retrieving any contents from the cache.
+ *
+ * If the page is not backed by a file then -ENOBUFS will be returned and
+ * nothing more will be done, and no reservation will be made.
+ *
+ * Else, a block will be allocated if one wasn't already, and 0 will be
+ * returned
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_alloc_page(struct fscache_cookie *cookie,
+ struct page *page,
+ gfp_t gfp)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_alloc_page(cookie, page, gfp);
+ else
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_write_page - Request storage of a page in the cache
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page to store
+ * @gfp: The conditions under which memory allocation should be made
+ *
+ * Request the contents of the netfs page be written into the cache. This
+ * request may be ignored if no cache block is currently allocated, in which
+ * case it will return -ENOBUFS.
+ *
+ * If a cache block was already allocated, a write will be initiated and 0 will
+ * be returned. The PG_fscache_write page bit is set immediately and will then
+ * be cleared at the completion of the write to indicate the success or failure
+ * of the operation. Note that the completion may happen before the return.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_write_page(struct fscache_cookie *cookie,
+ struct page *page,
+ gfp_t gfp)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_write_page(cookie, page, gfp);
+ else
+ return -ENOBUFS;
+}
+
+/**
+ * fscache_uncache_page - Indicate that caching is no longer required on a page
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page that was being cached.
+ *
+ * Tell the cache that we no longer want a page to be cached and that it should
+ * remove any knowledge of the netfs page it may have.
+ *
+ * Note that this cannot cancel any outstanding I/O operations between this
+ * page and the cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_uncache_page(struct fscache_cookie *cookie,
+ struct page *page)
+{
+ if (fscache_cookie_valid(cookie))
+ __fscache_uncache_page(cookie, page);
+}
+
+/**
+ * fscache_check_page_write - Ask if a page is being writing to the cache
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page that is being cached.
+ *
+ * Ask the cache if a page is being written to the cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+bool fscache_check_page_write(struct fscache_cookie *cookie,
+ struct page *page)
+{
+ if (fscache_cookie_valid(cookie))
+ return __fscache_check_page_write(cookie, page);
+ return false;
+}
+
+/**
+ * fscache_wait_on_page_write - Wait for a page to complete writing to the cache
+ * @cookie: The cookie representing the cache object
+ * @page: The netfs page that is being cached.
+ *
+ * Ask the cache to wake us up when a page is no longer being written to the
+ * cache.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+void fscache_wait_on_page_write(struct fscache_cookie *cookie,
+ struct page *page)
+{
+ if (fscache_cookie_valid(cookie))
+ __fscache_wait_on_page_write(cookie, page);
+}
+
+#endif /* _LINUX_FSCACHE_H */
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index bde2557c2a9..fdffb413b19 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -185,6 +185,9 @@ struct nfs_inode {
fmode_t delegation_state;
struct rw_semaphore rwsem;
#endif /* CONFIG_NFS_V4*/
+#ifdef CONFIG_NFS_FSCACHE
+ struct fscache_cookie *fscache;
+#endif
struct inode vfs_inode;
};
@@ -207,6 +210,8 @@ struct nfs_inode {
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
#define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */
#define NFS_INO_FLUSHING (4) /* inode is flushing out data */
+#define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
+#define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */
static inline struct nfs_inode *NFS_I(const struct inode *inode)
{
@@ -260,6 +265,11 @@ static inline int NFS_STALE(const struct inode *inode)
return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
}
+static inline int NFS_FSCACHE(const struct inode *inode)
+{
+ return test_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
+}
+
static inline __u64 NFS_FILEID(const struct inode *inode)
{
return NFS_I(inode)->fileid;
@@ -506,6 +516,8 @@ extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
extern int nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
extern void nfs_readdata_release(void *data);
+extern int nfs_readpage_async(struct nfs_open_context *, struct inode *,
+ struct page *);
/*
* Allocate nfs_read_data structures
@@ -583,6 +595,7 @@ extern void * nfs_root_data(void);
#define NFSDBG_CALLBACK 0x0100
#define NFSDBG_CLIENT 0x0200
#define NFSDBG_MOUNT 0x0400
+#define NFSDBG_FSCACHE 0x0800
#define NFSDBG_ALL 0xFFFF
#ifdef __KERNEL__
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 29b1e40dce9..6ad75948cbf 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -64,6 +64,10 @@ struct nfs_client {
char cl_ipaddr[48];
unsigned char cl_id_uniquifier;
#endif
+
+#ifdef CONFIG_NFS_FSCACHE
+ struct fscache_cookie *fscache; /* client index cache cookie */
+#endif
};
/*
@@ -96,12 +100,19 @@ struct nfs_server {
unsigned int acdirmin;
unsigned int acdirmax;
unsigned int namelen;
+ unsigned int options; /* extra options enabled by mount */
+#define NFS_OPTION_FSCACHE 0x00000001 /* - local caching enabled */
struct nfs_fsid fsid;
__u64 maxfilesize; /* maximum file size */
unsigned long mount_time; /* when this fs was mounted */
dev_t s_dev; /* superblock dev numbers */
+#ifdef CONFIG_NFS_FSCACHE
+ struct nfs_fscache_key *fscache_key; /* unique key for superblock */
+ struct fscache_cookie *fscache; /* superblock cookie */
+#endif
+
#ifdef CONFIG_NFS_V4
u32 attr_bitmask[2];/* V4 bitmask representing the set
of attributes supported on this
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 1cb9a3fed2b..68b10f5f890 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -116,4 +116,16 @@ enum nfs_stat_eventcounters {
__NFSIOS_COUNTSMAX,
};
+/*
+ * NFS local caching servicing counters
+ */
+enum nfs_stat_fscachecounters {
+ NFSIOS_FSCACHE_PAGES_READ_OK,
+ NFSIOS_FSCACHE_PAGES_READ_FAIL,
+ NFSIOS_FSCACHE_PAGES_WRITTEN_OK,
+ NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL,
+ NFSIOS_FSCACHE_PAGES_UNCACHED,
+ __NFSIOS_FSCACHEMAX,
+};
+
#endif /* _LINUX_NFS_IOSTAT */
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 61df1779b2a..62214c7d2d9 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -82,6 +82,7 @@ enum pageflags {
PG_arch_1,
PG_reserved,
PG_private, /* If pagecache, has fs-private data */
+ PG_private_2, /* If pagecache, has fs aux data */
PG_writeback, /* Page is under writeback */
#ifdef CONFIG_PAGEFLAGS_EXTENDED
PG_head, /* A head page */
@@ -108,6 +109,12 @@ enum pageflags {
/* Filesystems */
PG_checked = PG_owner_priv_1,
+ /* Two page bits are conscripted by FS-Cache to maintain local caching
+ * state. These bits are set on pages belonging to the netfs's inodes
+ * when those inodes are being locally cached.
+ */
+ PG_fscache = PG_private_2, /* page backed by cache */
+
/* XEN */
PG_pinned = PG_owner_priv_1,
PG_savepinned = PG_dirty,
@@ -182,7 +189,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; }
struct page; /* forward declaration */
-TESTPAGEFLAG(Locked, locked)
+TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked)
PAGEFLAG(Error, error)
PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
@@ -194,8 +201,6 @@ PAGEFLAG(Checked, checked) /* Used by some filesystems */
PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */
PAGEFLAG(SavePinned, savepinned); /* Xen */
PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
-PAGEFLAG(Private, private) __CLEARPAGEFLAG(Private, private)
- __SETPAGEFLAG(Private, private)
PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
__PAGEFLAG(SlobPage, slob_page)
@@ -205,6 +210,16 @@ __PAGEFLAG(SlubFrozen, slub_frozen)
__PAGEFLAG(SlubDebug, slub_debug)
/*
+ * Private page markings that may be used by the filesystem that owns the page
+ * for its own purposes.
+ * - PG_private and PG_private_2 cause releasepage() and co to be invoked
+ */
+PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private)
+ __CLEARPAGEFLAG(Private, private)
+PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2)
+PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1)
+
+/*
* Only test-and-set exist for PG_writeback. The unconditional operators are
* risky: they bypass page accounting.
*/
@@ -384,9 +399,10 @@ static inline void __ClearPageTail(struct page *page)
* these flags set. It they are, there is a problem.
*/
#define PAGE_FLAGS_CHECK_AT_FREE \
- (1 << PG_lru | 1 << PG_private | 1 << PG_locked | \
- 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
- 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
+ (1 << PG_lru | 1 << PG_locked | \
+ 1 << PG_private | 1 << PG_private_2 | \
+ 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
+ 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
__PG_UNEVICTABLE | __PG_MLOCKED)
/*
@@ -397,4 +413,16 @@ static inline void __ClearPageTail(struct page *page)
#define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1)
#endif /* !__GENERATING_BOUNDS_H */
+
+/**
+ * page_has_private - Determine if page has private stuff
+ * @page: The page to be checked
+ *
+ * Determine if a page has private stuff, indicating that release routines
+ * should be invoked upon it.
+ */
+#define page_has_private(page) \
+ ((page)->flags & ((1 << PG_private) | \
+ (1 << PG_private_2)))
+
#endif /* PAGE_FLAGS_H */
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 076a7dc67c2..34da5230faa 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -384,6 +384,11 @@ static inline void wait_on_page_writeback(struct page *page)
extern void end_page_writeback(struct page *page);
/*
+ * Add an arbitrary waiter to a page's wait queue
+ */
+extern void add_page_wait_queue(struct page *page, wait_queue_t *waiter);
+
+/*
* Fault a userspace page into pagetables. Return non-zero on a fault.
*
* This assumes that two userspace pages are always sufficient. That's
diff --git a/include/linux/slow-work.h b/include/linux/slow-work.h
new file mode 100644
index 00000000000..85958277f83
--- /dev/null
+++ b/include/linux/slow-work.h
@@ -0,0 +1,95 @@
+/* Worker thread pool for slow items, such as filesystem lookups or mkdirs
+ *
+ * Copyright (C) 2008 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.
+ *
+ * See Documentation/slow-work.txt
+ */
+
+#ifndef _LINUX_SLOW_WORK_H
+#define _LINUX_SLOW_WORK_H
+
+#ifdef CONFIG_SLOW_WORK
+
+#include <linux/sysctl.h>
+
+struct slow_work;
+
+/*
+ * The operations used to support slow work items
+ */
+struct slow_work_ops {
+ /* get a ref on a work item
+ * - return 0 if successful, -ve if not
+ */
+ int (*get_ref)(struct slow_work *work);
+
+ /* discard a ref to a work item */
+ void (*put_ref)(struct slow_work *work);
+
+ /* execute a work item */
+ void (*execute)(struct slow_work *work);
+};
+
+/*
+ * A slow work item
+ * - A reference is held on the parent object by the thread pool when it is
+ * queued
+ */
+struct slow_work {
+ unsigned long flags;
+#define SLOW_WORK_PENDING 0 /* item pending (further) execution */
+#define SLOW_WORK_EXECUTING 1 /* item currently executing */
+#define SLOW_WORK_ENQ_DEFERRED 2 /* item enqueue deferred */
+#define SLOW_WORK_VERY_SLOW 3 /* item is very slow */
+ const struct slow_work_ops *ops; /* operations table for this item */
+ struct list_head link; /* link in queue */
+};
+
+/**
+ * slow_work_init - Initialise a slow work item
+ * @work: The work item to initialise
+ * @ops: The operations to use to handle the slow work item
+ *
+ * Initialise a slow work item.
+ */
+static inline void slow_work_init(struct slow_work *work,
+ const struct slow_work_ops *ops)
+{
+ work->flags = 0;
+ work->ops = ops;
+ INIT_LIST_HEAD(&work->link);
+}
+
+/**
+ * slow_work_init - Initialise a very slow work item
+ * @work: The work item to initialise
+ * @ops: The operations to use to handle the slow work item
+ *
+ * Initialise a very slow work item. This item will be restricted such that
+ * only a certain number of the pool threads will be able to execute items of
+ * this type.
+ */
+static inline void vslow_work_init(struct slow_work *work,
+ const struct slow_work_ops *ops)
+{
+ work->flags = 1 << SLOW_WORK_VERY_SLOW;
+ work->ops = ops;
+ INIT_LIST_HEAD(&work->link);
+}
+
+extern int slow_work_enqueue(struct slow_work *work);
+extern int slow_work_register_user(void);
+extern void slow_work_unregister_user(void);
+
+#ifdef CONFIG_SYSCTL
+extern ctl_table slow_work_sysctls[];
+#endif
+
+#endif /* CONFIG_SLOW_WORK */
+#endif /* _LINUX_SLOW_WORK_H */