mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 04:20:53 +07:00
docs: filesystems: caching/backend-api.txt: convert it to ReST
- Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add it to filesystems/caching/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5d0a61abaa87bfe913b9e2f321e74ef7af0f3dfc.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
parent
d74802ade7
commit
0e822145b5
@ -1,6 +1,8 @@
|
|||||||
==========================
|
.. SPDX-License-Identifier: GPL-2.0
|
||||||
FS-CACHE CACHE BACKEND API
|
|
||||||
==========================
|
==========================
|
||||||
|
FS-Cache Cache backend API
|
||||||
|
==========================
|
||||||
|
|
||||||
The FS-Cache system provides an API by which actual caches can be supplied to
|
The FS-Cache system provides an API by which actual caches can be supplied to
|
||||||
FS-Cache for it to then serve out to network filesystems and other interested
|
FS-Cache for it to then serve out to network filesystems and other interested
|
||||||
@ -9,15 +11,14 @@ parties.
|
|||||||
This API is declared in <linux/fscache-cache.h>.
|
This API is declared in <linux/fscache-cache.h>.
|
||||||
|
|
||||||
|
|
||||||
====================================
|
Initialising and Registering a Cache
|
||||||
INITIALISING AND REGISTERING A CACHE
|
|
||||||
====================================
|
====================================
|
||||||
|
|
||||||
To start off, a cache definition must be initialised and registered for each
|
To start off, a cache definition must be initialised and registered for each
|
||||||
cache the backend wants to make available. For instance, CacheFS does this in
|
cache the backend wants to make available. For instance, CacheFS does this in
|
||||||
the fill_super() operation on mounting.
|
the fill_super() operation on mounting.
|
||||||
|
|
||||||
The cache definition (struct fscache_cache) should be initialised by calling:
|
The cache definition (struct fscache_cache) should be initialised by calling::
|
||||||
|
|
||||||
void fscache_init_cache(struct fscache_cache *cache,
|
void fscache_init_cache(struct fscache_cache *cache,
|
||||||
struct fscache_cache_ops *ops,
|
struct fscache_cache_ops *ops,
|
||||||
@ -26,17 +27,17 @@ The cache definition (struct fscache_cache) should be initialised by calling:
|
|||||||
|
|
||||||
Where:
|
Where:
|
||||||
|
|
||||||
(*) "cache" is a pointer to the cache definition;
|
* "cache" is a pointer to the cache definition;
|
||||||
|
|
||||||
(*) "ops" is a pointer to the table of operations that the backend supports on
|
* "ops" is a pointer to the table of operations that the backend supports on
|
||||||
this cache; and
|
this cache; and
|
||||||
|
|
||||||
(*) "idfmt" is a format and printf-style arguments for constructing a label
|
* "idfmt" is a format and printf-style arguments for constructing a label
|
||||||
for the cache.
|
for the cache.
|
||||||
|
|
||||||
|
|
||||||
The cache should then be registered with FS-Cache by passing a pointer to the
|
The cache should then be registered with FS-Cache by passing a pointer to the
|
||||||
previously initialised cache definition to:
|
previously initialised cache definition to::
|
||||||
|
|
||||||
int fscache_add_cache(struct fscache_cache *cache,
|
int fscache_add_cache(struct fscache_cache *cache,
|
||||||
struct fscache_object *fsdef,
|
struct fscache_object *fsdef,
|
||||||
@ -44,12 +45,12 @@ previously initialised cache definition to:
|
|||||||
|
|
||||||
Two extra arguments should also be supplied:
|
Two extra arguments should also be supplied:
|
||||||
|
|
||||||
(*) "fsdef" which should point to the object representation for the FS-Cache
|
* "fsdef" which should point to the object representation for the FS-Cache
|
||||||
master index in this cache. Netfs primary index entries will be created
|
master index in this cache. Netfs primary index entries will be created
|
||||||
here. FS-Cache keeps the caller's reference to the index object if
|
here. FS-Cache keeps the caller's reference to the index object if
|
||||||
successful and will release it upon withdrawal of the cache.
|
successful and will release it upon withdrawal of the cache.
|
||||||
|
|
||||||
(*) "tagname" which, if given, should be a text string naming this cache. If
|
* "tagname" which, if given, should be a text string naming this cache. If
|
||||||
this is NULL, the identifier will be used instead. For CacheFS, the
|
this is NULL, the identifier will be used instead. For CacheFS, the
|
||||||
identifier is set to name the underlying block device and the tag can be
|
identifier is set to name the underlying block device and the tag can be
|
||||||
supplied by mount.
|
supplied by mount.
|
||||||
@ -58,20 +59,18 @@ This function may return -ENOMEM if it ran out of memory or -EEXIST if the tag
|
|||||||
is already in use. 0 will be returned on success.
|
is already in use. 0 will be returned on success.
|
||||||
|
|
||||||
|
|
||||||
=====================
|
Unregistering a Cache
|
||||||
UNREGISTERING A CACHE
|
|
||||||
=====================
|
=====================
|
||||||
|
|
||||||
A cache can be withdrawn from the system by calling this function with a
|
A cache can be withdrawn from the system by calling this function with a
|
||||||
pointer to the cache definition:
|
pointer to the cache definition::
|
||||||
|
|
||||||
void fscache_withdraw_cache(struct fscache_cache *cache);
|
void fscache_withdraw_cache(struct fscache_cache *cache);
|
||||||
|
|
||||||
In CacheFS's case, this is called by put_super().
|
In CacheFS's case, this is called by put_super().
|
||||||
|
|
||||||
|
|
||||||
========
|
Security
|
||||||
SECURITY
|
|
||||||
========
|
========
|
||||||
|
|
||||||
The cache methods are executed one of two contexts:
|
The cache methods are executed one of two contexts:
|
||||||
@ -89,8 +88,7 @@ be masqueraded for the duration of the cache driver's access to the cache.
|
|||||||
This is left to the cache to handle; FS-Cache makes no effort in this regard.
|
This is left to the cache to handle; FS-Cache makes no effort in this regard.
|
||||||
|
|
||||||
|
|
||||||
===================================
|
Control and Statistics Presentation
|
||||||
CONTROL AND STATISTICS PRESENTATION
|
|
||||||
===================================
|
===================================
|
||||||
|
|
||||||
The cache may present data to the outside world through FS-Cache's interfaces
|
The cache may present data to the outside world through FS-Cache's interfaces
|
||||||
@ -101,11 +99,10 @@ is enabled. This is accessible through the kobject struct fscache_cache::kobj
|
|||||||
and is for use by the cache as it sees fit.
|
and is for use by the cache as it sees fit.
|
||||||
|
|
||||||
|
|
||||||
========================
|
Relevant Data Structures
|
||||||
RELEVANT DATA STRUCTURES
|
|
||||||
========================
|
========================
|
||||||
|
|
||||||
(*) Index/Data file FS-Cache representation cookie:
|
* Index/Data file FS-Cache representation cookie::
|
||||||
|
|
||||||
struct fscache_cookie {
|
struct fscache_cookie {
|
||||||
struct fscache_object_def *def;
|
struct fscache_object_def *def;
|
||||||
@ -121,7 +118,7 @@ RELEVANT DATA STRUCTURES
|
|||||||
cache operations.
|
cache operations.
|
||||||
|
|
||||||
|
|
||||||
(*) In-cache object representation:
|
* In-cache object representation::
|
||||||
|
|
||||||
struct fscache_object {
|
struct fscache_object {
|
||||||
int debug_id;
|
int debug_id;
|
||||||
@ -150,7 +147,7 @@ RELEVANT DATA STRUCTURES
|
|||||||
initialised by calling fscache_object_init(object).
|
initialised by calling fscache_object_init(object).
|
||||||
|
|
||||||
|
|
||||||
(*) FS-Cache operation record:
|
* FS-Cache operation record::
|
||||||
|
|
||||||
struct fscache_operation {
|
struct fscache_operation {
|
||||||
atomic_t usage;
|
atomic_t usage;
|
||||||
@ -173,7 +170,7 @@ RELEVANT DATA STRUCTURES
|
|||||||
an operation needs more processing time, it should be enqueued again.
|
an operation needs more processing time, it should be enqueued again.
|
||||||
|
|
||||||
|
|
||||||
(*) FS-Cache retrieval operation record:
|
* FS-Cache retrieval operation record::
|
||||||
|
|
||||||
struct fscache_retrieval {
|
struct fscache_retrieval {
|
||||||
struct fscache_operation op;
|
struct fscache_operation op;
|
||||||
@ -198,7 +195,7 @@ RELEVANT DATA STRUCTURES
|
|||||||
it sees fit.
|
it sees fit.
|
||||||
|
|
||||||
|
|
||||||
(*) FS-Cache storage operation record:
|
* FS-Cache storage operation record::
|
||||||
|
|
||||||
struct fscache_storage {
|
struct fscache_storage {
|
||||||
struct fscache_operation op;
|
struct fscache_operation op;
|
||||||
@ -212,16 +209,17 @@ RELEVANT DATA STRUCTURES
|
|||||||
storage.
|
storage.
|
||||||
|
|
||||||
|
|
||||||
================
|
Cache Operations
|
||||||
CACHE OPERATIONS
|
|
||||||
================
|
================
|
||||||
|
|
||||||
The cache backend provides FS-Cache with a table of operations that can be
|
The cache backend provides FS-Cache with a table of operations that can be
|
||||||
performed on the denizens of the cache. These are held in a structure of type:
|
performed on the denizens of the cache. These are held in a structure of type:
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
struct fscache_cache_ops
|
struct fscache_cache_ops
|
||||||
|
|
||||||
(*) Name of cache provider [mandatory]:
|
* Name of cache provider [mandatory]::
|
||||||
|
|
||||||
const char *name
|
const char *name
|
||||||
|
|
||||||
@ -229,7 +227,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
the backend.
|
the backend.
|
||||||
|
|
||||||
|
|
||||||
(*) Allocate a new object [mandatory]:
|
* Allocate a new object [mandatory]::
|
||||||
|
|
||||||
struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
|
struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
|
||||||
struct fscache_cookie *cookie)
|
struct fscache_cookie *cookie)
|
||||||
@ -244,7 +242,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
form once lookup is complete or aborted.
|
form once lookup is complete or aborted.
|
||||||
|
|
||||||
|
|
||||||
(*) Look up and create object [mandatory]:
|
* Look up and create object [mandatory]::
|
||||||
|
|
||||||
void (*lookup_object)(struct fscache_object *object)
|
void (*lookup_object)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -263,7 +261,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
to abort the lookup of that object.
|
to abort the lookup of that object.
|
||||||
|
|
||||||
|
|
||||||
(*) Release lookup data [mandatory]:
|
* Release lookup data [mandatory]::
|
||||||
|
|
||||||
void (*lookup_complete)(struct fscache_object *object)
|
void (*lookup_complete)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -271,7 +269,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
using to perform a lookup.
|
using to perform a lookup.
|
||||||
|
|
||||||
|
|
||||||
(*) Increment object refcount [mandatory]:
|
* Increment object refcount [mandatory]::
|
||||||
|
|
||||||
struct fscache_object *(*grab_object)(struct fscache_object *object)
|
struct fscache_object *(*grab_object)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -280,7 +278,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
It should return the object pointer if successful.
|
It should return the object pointer if successful.
|
||||||
|
|
||||||
|
|
||||||
(*) Lock/Unlock object [mandatory]:
|
* Lock/Unlock object [mandatory]::
|
||||||
|
|
||||||
void (*lock_object)(struct fscache_object *object)
|
void (*lock_object)(struct fscache_object *object)
|
||||||
void (*unlock_object)(struct fscache_object *object)
|
void (*unlock_object)(struct fscache_object *object)
|
||||||
@ -289,7 +287,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
to schedule with the lock held, so a spinlock isn't sufficient.
|
to schedule with the lock held, so a spinlock isn't sufficient.
|
||||||
|
|
||||||
|
|
||||||
(*) Pin/Unpin object [optional]:
|
* Pin/Unpin object [optional]::
|
||||||
|
|
||||||
int (*pin_object)(struct fscache_object *object)
|
int (*pin_object)(struct fscache_object *object)
|
||||||
void (*unpin_object)(struct fscache_object *object)
|
void (*unpin_object)(struct fscache_object *object)
|
||||||
@ -299,7 +297,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
enough space in the cache to permit this.
|
enough space in the cache to permit this.
|
||||||
|
|
||||||
|
|
||||||
(*) Check coherency state of an object [mandatory]:
|
* Check coherency state of an object [mandatory]::
|
||||||
|
|
||||||
int (*check_consistency)(struct fscache_object *object)
|
int (*check_consistency)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -308,7 +306,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
if they're consistent and -ESTALE otherwise. -ENOMEM and -ERESTARTSYS
|
if they're consistent and -ESTALE otherwise. -ENOMEM and -ERESTARTSYS
|
||||||
may also be returned.
|
may also be returned.
|
||||||
|
|
||||||
(*) Update object [mandatory]:
|
* Update object [mandatory]::
|
||||||
|
|
||||||
int (*update_object)(struct fscache_object *object)
|
int (*update_object)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -317,7 +315,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
obtained by calling object->cookie->def->get_aux()/get_attr().
|
obtained by calling object->cookie->def->get_aux()/get_attr().
|
||||||
|
|
||||||
|
|
||||||
(*) Invalidate data object [mandatory]:
|
* Invalidate data object [mandatory]::
|
||||||
|
|
||||||
int (*invalidate_object)(struct fscache_operation *op)
|
int (*invalidate_object)(struct fscache_operation *op)
|
||||||
|
|
||||||
@ -329,7 +327,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
fscache_op_complete() must be called on op before returning.
|
fscache_op_complete() must be called on op before returning.
|
||||||
|
|
||||||
|
|
||||||
(*) Discard object [mandatory]:
|
* Discard object [mandatory]::
|
||||||
|
|
||||||
void (*drop_object)(struct fscache_object *object)
|
void (*drop_object)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -341,7 +339,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
caller. The caller will invoke the put_object() method as appropriate.
|
caller. The caller will invoke the put_object() method as appropriate.
|
||||||
|
|
||||||
|
|
||||||
(*) Release object reference [mandatory]:
|
* Release object reference [mandatory]::
|
||||||
|
|
||||||
void (*put_object)(struct fscache_object *object)
|
void (*put_object)(struct fscache_object *object)
|
||||||
|
|
||||||
@ -349,7 +347,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
be freed when all the references to it are released.
|
be freed when all the references to it are released.
|
||||||
|
|
||||||
|
|
||||||
(*) Synchronise a cache [mandatory]:
|
* Synchronise a cache [mandatory]::
|
||||||
|
|
||||||
void (*sync)(struct fscache_cache *cache)
|
void (*sync)(struct fscache_cache *cache)
|
||||||
|
|
||||||
@ -357,7 +355,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
device.
|
device.
|
||||||
|
|
||||||
|
|
||||||
(*) Dissociate a cache [mandatory]:
|
* Dissociate a cache [mandatory]::
|
||||||
|
|
||||||
void (*dissociate_pages)(struct fscache_cache *cache)
|
void (*dissociate_pages)(struct fscache_cache *cache)
|
||||||
|
|
||||||
@ -365,7 +363,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
cache withdrawal.
|
cache withdrawal.
|
||||||
|
|
||||||
|
|
||||||
(*) Notification that the attributes on a netfs file changed [mandatory]:
|
* Notification that the attributes on a netfs file changed [mandatory]::
|
||||||
|
|
||||||
int (*attr_changed)(struct fscache_object *object);
|
int (*attr_changed)(struct fscache_object *object);
|
||||||
|
|
||||||
@ -386,7 +384,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
execution of this operation.
|
execution of this operation.
|
||||||
|
|
||||||
|
|
||||||
(*) Reserve cache space for an object's data [optional]:
|
* Reserve cache space for an object's data [optional]::
|
||||||
|
|
||||||
int (*reserve_space)(struct fscache_object *object, loff_t size);
|
int (*reserve_space)(struct fscache_object *object, loff_t size);
|
||||||
|
|
||||||
@ -404,7 +402,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
size if larger than that already.
|
size if larger than that already.
|
||||||
|
|
||||||
|
|
||||||
(*) Request page be read from cache [mandatory]:
|
* Request page be read from cache [mandatory]::
|
||||||
|
|
||||||
int (*read_or_alloc_page)(struct fscache_retrieval *op,
|
int (*read_or_alloc_page)(struct fscache_retrieval *op,
|
||||||
struct page *page,
|
struct page *page,
|
||||||
@ -446,7 +444,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
with. This will complete the operation when all pages are dealt with.
|
with. This will complete the operation when all pages are dealt with.
|
||||||
|
|
||||||
|
|
||||||
(*) Request pages be read from cache [mandatory]:
|
* Request pages be read from cache [mandatory]::
|
||||||
|
|
||||||
int (*read_or_alloc_pages)(struct fscache_retrieval *op,
|
int (*read_or_alloc_pages)(struct fscache_retrieval *op,
|
||||||
struct list_head *pages,
|
struct list_head *pages,
|
||||||
@ -457,7 +455,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
of pages instead of one page. Any pages on which a read operation is
|
of pages instead of one page. Any pages on which a read operation is
|
||||||
started must be added to the page cache for the specified mapping and also
|
started must be added to the page cache for the specified mapping and also
|
||||||
to the LRU. Such pages must also be removed from the pages list and
|
to the LRU. Such pages must also be removed from the pages list and
|
||||||
*nr_pages decremented per page.
|
``*nr_pages`` decremented per page.
|
||||||
|
|
||||||
If there was an error such as -ENOMEM, then that should be returned; else
|
If there was an error such as -ENOMEM, then that should be returned; else
|
||||||
if one or more pages couldn't be read or allocated, then -ENOBUFS should
|
if one or more pages couldn't be read or allocated, then -ENOBUFS should
|
||||||
@ -466,7 +464,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
returned.
|
returned.
|
||||||
|
|
||||||
|
|
||||||
(*) Request page be allocated in the cache [mandatory]:
|
* Request page be allocated in the cache [mandatory]::
|
||||||
|
|
||||||
int (*allocate_page)(struct fscache_retrieval *op,
|
int (*allocate_page)(struct fscache_retrieval *op,
|
||||||
struct page *page,
|
struct page *page,
|
||||||
@ -482,7 +480,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
allocated, then the netfs page should be marked and 0 returned.
|
allocated, then the netfs page should be marked and 0 returned.
|
||||||
|
|
||||||
|
|
||||||
(*) Request pages be allocated in the cache [mandatory]:
|
* Request pages be allocated in the cache [mandatory]::
|
||||||
|
|
||||||
int (*allocate_pages)(struct fscache_retrieval *op,
|
int (*allocate_pages)(struct fscache_retrieval *op,
|
||||||
struct list_head *pages,
|
struct list_head *pages,
|
||||||
@ -493,7 +491,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
nr_pages should be treated as for the read_or_alloc_pages() method.
|
nr_pages should be treated as for the read_or_alloc_pages() method.
|
||||||
|
|
||||||
|
|
||||||
(*) Request page be written to cache [mandatory]:
|
* Request page be written to cache [mandatory]::
|
||||||
|
|
||||||
int (*write_page)(struct fscache_storage *op,
|
int (*write_page)(struct fscache_storage *op,
|
||||||
struct page *page);
|
struct page *page);
|
||||||
@ -514,7 +512,7 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
appropriately.
|
appropriately.
|
||||||
|
|
||||||
|
|
||||||
(*) Discard retained per-page metadata [mandatory]:
|
* Discard retained per-page metadata [mandatory]::
|
||||||
|
|
||||||
void (*uncache_page)(struct fscache_object *object, struct page *page)
|
void (*uncache_page)(struct fscache_object *object, struct page *page)
|
||||||
|
|
||||||
@ -523,13 +521,12 @@ performed on the denizens of the cache. These are held in a structure of type:
|
|||||||
maintains for this page.
|
maintains for this page.
|
||||||
|
|
||||||
|
|
||||||
==================
|
FS-Cache Utilities
|
||||||
FS-CACHE UTILITIES
|
|
||||||
==================
|
==================
|
||||||
|
|
||||||
FS-Cache provides some utilities that a cache backend may make use of:
|
FS-Cache provides some utilities that a cache backend may make use of:
|
||||||
|
|
||||||
(*) Note occurrence of an I/O error in a cache:
|
* Note occurrence of an I/O error in a cache::
|
||||||
|
|
||||||
void fscache_io_error(struct fscache_cache *cache)
|
void fscache_io_error(struct fscache_cache *cache)
|
||||||
|
|
||||||
@ -541,7 +538,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
This does not actually withdraw the cache. That must be done separately.
|
This does not actually withdraw the cache. That must be done separately.
|
||||||
|
|
||||||
|
|
||||||
(*) Invoke the retrieval I/O completion function:
|
* Invoke the retrieval I/O completion function::
|
||||||
|
|
||||||
void fscache_end_io(struct fscache_retrieval *op, struct page *page,
|
void fscache_end_io(struct fscache_retrieval *op, struct page *page,
|
||||||
int error);
|
int error);
|
||||||
@ -550,8 +547,8 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
error value should be 0 if successful and an error otherwise.
|
error value should be 0 if successful and an error otherwise.
|
||||||
|
|
||||||
|
|
||||||
(*) Record that one or more pages being retrieved or allocated have been dealt
|
* Record that one or more pages being retrieved or allocated have been dealt
|
||||||
with:
|
with::
|
||||||
|
|
||||||
void fscache_retrieval_complete(struct fscache_retrieval *op,
|
void fscache_retrieval_complete(struct fscache_retrieval *op,
|
||||||
int n_pages);
|
int n_pages);
|
||||||
@ -562,7 +559,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
completed.
|
completed.
|
||||||
|
|
||||||
|
|
||||||
(*) Record operation completion:
|
* Record operation completion::
|
||||||
|
|
||||||
void fscache_op_complete(struct fscache_operation *op);
|
void fscache_op_complete(struct fscache_operation *op);
|
||||||
|
|
||||||
@ -571,7 +568,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
one or more pending operations to start running.
|
one or more pending operations to start running.
|
||||||
|
|
||||||
|
|
||||||
(*) Set highest store limit:
|
* Set highest store limit::
|
||||||
|
|
||||||
void fscache_set_store_limit(struct fscache_object *object,
|
void fscache_set_store_limit(struct fscache_object *object,
|
||||||
loff_t i_size);
|
loff_t i_size);
|
||||||
@ -581,7 +578,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
rejected by fscache_read_alloc_page() and co with -ENOBUFS.
|
rejected by fscache_read_alloc_page() and co with -ENOBUFS.
|
||||||
|
|
||||||
|
|
||||||
(*) Mark pages as being cached:
|
* Mark pages as being cached::
|
||||||
|
|
||||||
void fscache_mark_pages_cached(struct fscache_retrieval *op,
|
void fscache_mark_pages_cached(struct fscache_retrieval *op,
|
||||||
struct pagevec *pagevec);
|
struct pagevec *pagevec);
|
||||||
@ -590,7 +587,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
the netfs must call fscache_uncache_page() to unmark the pages.
|
the netfs must call fscache_uncache_page() to unmark the pages.
|
||||||
|
|
||||||
|
|
||||||
(*) Perform coherency check on an object:
|
* Perform coherency check on an object::
|
||||||
|
|
||||||
enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
|
enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
|
||||||
const void *data,
|
const void *data,
|
||||||
@ -603,29 +600,26 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
|
|
||||||
One of three values will be returned:
|
One of three values will be returned:
|
||||||
|
|
||||||
(*) FSCACHE_CHECKAUX_OKAY
|
FSCACHE_CHECKAUX_OKAY
|
||||||
|
|
||||||
The coherency data indicates the object is valid as is.
|
The coherency data indicates the object is valid as is.
|
||||||
|
|
||||||
(*) FSCACHE_CHECKAUX_NEEDS_UPDATE
|
FSCACHE_CHECKAUX_NEEDS_UPDATE
|
||||||
|
|
||||||
The coherency data needs updating, but otherwise the object is
|
The coherency data needs updating, but otherwise the object is
|
||||||
valid.
|
valid.
|
||||||
|
|
||||||
(*) FSCACHE_CHECKAUX_OBSOLETE
|
FSCACHE_CHECKAUX_OBSOLETE
|
||||||
|
|
||||||
The coherency data indicates that the object is obsolete and should
|
The coherency data indicates that the object is obsolete and should
|
||||||
be discarded.
|
be discarded.
|
||||||
|
|
||||||
|
|
||||||
(*) Initialise a freshly allocated object:
|
* Initialise a freshly allocated object::
|
||||||
|
|
||||||
void fscache_object_init(struct fscache_object *object);
|
void fscache_object_init(struct fscache_object *object);
|
||||||
|
|
||||||
This initialises all the fields in an object representation.
|
This initialises all the fields in an object representation.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate the destruction of an object:
|
* Indicate the destruction of an object::
|
||||||
|
|
||||||
void fscache_object_destroyed(struct fscache_cache *cache);
|
void fscache_object_destroyed(struct fscache_cache *cache);
|
||||||
|
|
||||||
@ -635,7 +629,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
all the objects.
|
all the objects.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate negative lookup on an object:
|
* Indicate negative lookup on an object::
|
||||||
|
|
||||||
void fscache_object_lookup_negative(struct fscache_object *object);
|
void fscache_object_lookup_negative(struct fscache_object *object);
|
||||||
|
|
||||||
@ -650,7 +644,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
significant - all subsequent calls are ignored.
|
significant - all subsequent calls are ignored.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate an object has been obtained:
|
* Indicate an object has been obtained::
|
||||||
|
|
||||||
void fscache_obtained_object(struct fscache_object *object);
|
void fscache_obtained_object(struct fscache_object *object);
|
||||||
|
|
||||||
@ -667,7 +661,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
(2) that writes may now proceed against this object.
|
(2) that writes may now proceed against this object.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate that object lookup failed:
|
* Indicate that object lookup failed::
|
||||||
|
|
||||||
void fscache_object_lookup_error(struct fscache_object *object);
|
void fscache_object_lookup_error(struct fscache_object *object);
|
||||||
|
|
||||||
@ -676,7 +670,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
as possible.
|
as possible.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate that a stale object was found and discarded:
|
* Indicate that a stale object was found and discarded::
|
||||||
|
|
||||||
void fscache_object_retrying_stale(struct fscache_object *object);
|
void fscache_object_retrying_stale(struct fscache_object *object);
|
||||||
|
|
||||||
@ -685,7 +679,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
discarded from the cache and the lookup will be performed again.
|
discarded from the cache and the lookup will be performed again.
|
||||||
|
|
||||||
|
|
||||||
(*) Indicate that the caching backend killed an object:
|
* Indicate that the caching backend killed an object::
|
||||||
|
|
||||||
void fscache_object_mark_killed(struct fscache_object *object,
|
void fscache_object_mark_killed(struct fscache_object *object,
|
||||||
enum fscache_why_object_killed why);
|
enum fscache_why_object_killed why);
|
||||||
@ -693,13 +687,20 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
This is called to indicate that the cache backend preemptively killed an
|
This is called to indicate that the cache backend preemptively killed an
|
||||||
object. The why parameter should be set to indicate the reason:
|
object. The why parameter should be set to indicate the reason:
|
||||||
|
|
||||||
FSCACHE_OBJECT_IS_STALE - the object was stale and needs discarding.
|
FSCACHE_OBJECT_IS_STALE
|
||||||
FSCACHE_OBJECT_NO_SPACE - there was insufficient cache space
|
- the object was stale and needs discarding.
|
||||||
FSCACHE_OBJECT_WAS_RETIRED - the object was retired when relinquished.
|
|
||||||
FSCACHE_OBJECT_WAS_CULLED - the object was culled to make space.
|
FSCACHE_OBJECT_NO_SPACE
|
||||||
|
- there was insufficient cache space
|
||||||
|
|
||||||
|
FSCACHE_OBJECT_WAS_RETIRED
|
||||||
|
- the object was retired when relinquished.
|
||||||
|
|
||||||
|
FSCACHE_OBJECT_WAS_CULLED
|
||||||
|
- the object was culled to make space.
|
||||||
|
|
||||||
|
|
||||||
(*) Get and release references on a retrieval record:
|
* Get and release references on a retrieval record::
|
||||||
|
|
||||||
void fscache_get_retrieval(struct fscache_retrieval *op);
|
void fscache_get_retrieval(struct fscache_retrieval *op);
|
||||||
void fscache_put_retrieval(struct fscache_retrieval *op);
|
void fscache_put_retrieval(struct fscache_retrieval *op);
|
||||||
@ -708,7 +709,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
asynchronous data retrieval and block allocation.
|
asynchronous data retrieval and block allocation.
|
||||||
|
|
||||||
|
|
||||||
(*) Enqueue a retrieval record for processing.
|
* Enqueue a retrieval record for processing::
|
||||||
|
|
||||||
void fscache_enqueue_retrieval(struct fscache_retrieval *op);
|
void fscache_enqueue_retrieval(struct fscache_retrieval *op);
|
||||||
|
|
||||||
@ -718,7 +719,7 @@ FS-Cache provides some utilities that a cache backend may make use of:
|
|||||||
within the callback function.
|
within the callback function.
|
||||||
|
|
||||||
|
|
||||||
(*) List of object state names:
|
* List of object state names::
|
||||||
|
|
||||||
const char *fscache_object_states[];
|
const char *fscache_object_states[];
|
||||||
|
|
@ -187,7 +187,7 @@ The netfs API to FS-Cache can be found in:
|
|||||||
|
|
||||||
The cache backend API to FS-Cache can be found in:
|
The cache backend API to FS-Cache can be found in:
|
||||||
|
|
||||||
Documentation/filesystems/caching/backend-api.txt
|
Documentation/filesystems/caching/backend-api.rst
|
||||||
|
|
||||||
A description of the internal representations and object state machine can be
|
A description of the internal representations and object state machine can be
|
||||||
found in:
|
found in:
|
||||||
|
@ -8,6 +8,7 @@ Filesystem Caching
|
|||||||
|
|
||||||
fscache
|
fscache
|
||||||
object
|
object
|
||||||
|
backend-api
|
||||||
cachefiles
|
cachefiles
|
||||||
netfs-api
|
netfs-api
|
||||||
operations
|
operations
|
||||||
|
@ -172,7 +172,7 @@ struct fscache_cache *fscache_select_cache_for_object(
|
|||||||
*
|
*
|
||||||
* Initialise a record of a cache and fill in the name.
|
* Initialise a record of a cache and fill in the name.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
void fscache_init_cache(struct fscache_cache *cache,
|
void fscache_init_cache(struct fscache_cache *cache,
|
||||||
@ -207,7 +207,7 @@ EXPORT_SYMBOL(fscache_init_cache);
|
|||||||
*
|
*
|
||||||
* Add a cache to the system, making it available for netfs's to use.
|
* Add a cache to the system, making it available for netfs's to use.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
int fscache_add_cache(struct fscache_cache *cache,
|
int fscache_add_cache(struct fscache_cache *cache,
|
||||||
@ -307,7 +307,7 @@ EXPORT_SYMBOL(fscache_add_cache);
|
|||||||
* Note that an I/O error occurred in a cache and that it should no longer be
|
* Note that an I/O error occurred in a cache and that it should no longer be
|
||||||
* used for anything. This also reports the error into the kernel log.
|
* used for anything. This also reports the error into the kernel log.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
void fscache_io_error(struct fscache_cache *cache)
|
void fscache_io_error(struct fscache_cache *cache)
|
||||||
@ -355,7 +355,7 @@ static void fscache_withdraw_all_objects(struct fscache_cache *cache,
|
|||||||
* Withdraw a cache from service, unbinding all its cache objects from the
|
* Withdraw a cache from service, unbinding all its cache objects from the
|
||||||
* netfs cookies they're currently representing.
|
* netfs cookies they're currently representing.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
void fscache_withdraw_cache(struct fscache_cache *cache)
|
void fscache_withdraw_cache(struct fscache_cache *cache)
|
||||||
|
@ -295,7 +295,7 @@ static void fscache_object_work_func(struct work_struct *work)
|
|||||||
*
|
*
|
||||||
* Initialise a cache object description to its basic values.
|
* Initialise a cache object description to its basic values.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
void fscache_object_init(struct fscache_object *object,
|
void fscache_object_init(struct fscache_object *object,
|
||||||
|
@ -6,7 +6,7 @@
|
|||||||
*
|
*
|
||||||
* NOTE!!! See:
|
* NOTE!!! See:
|
||||||
*
|
*
|
||||||
* Documentation/filesystems/caching/backend-api.txt
|
* Documentation/filesystems/caching/backend-api.rst
|
||||||
*
|
*
|
||||||
* for a description of the cache backend interface declared here.
|
* for a description of the cache backend interface declared here.
|
||||||
*/
|
*/
|
||||||
@ -454,7 +454,7 @@ static inline void fscache_object_lookup_error(struct fscache_object *object)
|
|||||||
* Set the maximum size an object is permitted to reach, implying the highest
|
* 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.
|
* byte that may be written. Intended to be called by the attr_changed() op.
|
||||||
*
|
*
|
||||||
* See Documentation/filesystems/caching/backend-api.txt for a complete
|
* See Documentation/filesystems/caching/backend-api.rst for a complete
|
||||||
* description.
|
* description.
|
||||||
*/
|
*/
|
||||||
static inline
|
static inline
|
||||||
|
Loading…
Reference in New Issue
Block a user