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Merge branch 'fscache-fixes' into for-next

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This commit is contained in:
Al Viro 2015-06-23 18:01:30 -04:00
commit 8ea3a7c0df
11 changed files with 397 additions and 203 deletions
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23
Documentation/filesystems/caching/backend-api.txt
View file

@ -676,6 +676,29 @@ FS-Cache provides some utilities that a cache backend may make use of:
as possible.
(*) Indicate that a stale object was found and discarded:
void fscache_object_retrying_stale(struct fscache_object *object);
This is called to indicate that the lookup procedure found an object in
the cache that the netfs decided was stale. The object has been
discarded from the cache and the lookup will be performed again.
(*) Indicate that the caching backend killed an object:
void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why);
This is called to indicate that the cache backend preemptively killed an
object. The why parameter should be set to indicate the reason:
FSCACHE_OBJECT_IS_STALE - the object was stale and needs discarding.
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:
void fscache_get_retrieval(struct fscache_retrieval *op);

7
Documentation/filesystems/caching/fscache.txt
View file

@ -284,8 +284,9 @@ proc files.
enq=N Number of times async ops queued for processing
can=N Number of async ops cancelled
rej=N Number of async ops rejected due to object lookup/create failure
ini=N Number of async ops initialised
dfr=N Number of async ops queued for deferred release
rel=N Number of async ops released
rel=N Number of async ops released (should equal ini=N when idle)
gc=N Number of deferred-release async ops garbage collected
CacheOp alo=N Number of in-progress alloc_object() cache ops
luo=N Number of in-progress lookup_object() cache ops
@ -303,6 +304,10 @@ proc files.
wrp=N Number of in-progress write_page() cache ops
ucp=N Number of in-progress uncache_page() cache ops
dsp=N Number of in-progress dissociate_pages() cache ops
CacheEv nsp=N Number of object lookups/creations rejected due to lack of space
stl=N Number of stale objects deleted
rtr=N Number of objects retired when relinquished
cul=N Number of objects culled
(*) /proc/fs/fscache/histogram

1
fs/cachefiles/internal.h
View file

@ -43,7 +43,6 @@ struct cachefiles_object {
loff_t i_size; /* object size */
unsigned long flags;
#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
#define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */
atomic_t usage; /* object usage count */
uint8_t type; /* object type */
uint8_t new; /* T if object new */

33
fs/cachefiles/namei.c
View file

@ -97,7 +97,8 @@ static noinline void cachefiles_printk_object(struct cachefiles_object *object,
* call vfs_unlink(), vfs_rmdir() or vfs_rename()
*/
static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
struct dentry *dentry)
struct dentry *dentry,
enum fscache_why_object_killed why)
{
struct cachefiles_object *object;
struct rb_node *p;
@ -132,8 +133,9 @@ static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
pr_err("\n");
pr_err("Error: Can't preemptively bury live object\n");
cachefiles_printk_object(object, NULL);
} else if (test_and_set_bit(CACHEFILES_OBJECT_BURIED, &object->flags)) {
pr_err("Error: Object already preemptively buried\n");
} else {
if (why != FSCACHE_OBJECT_IS_STALE)
fscache_object_mark_killed(&object->fscache, why);
}
write_unlock(&cache->active_lock);
@ -265,7 +267,8 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
static int cachefiles_bury_object(struct cachefiles_cache *cache,
struct dentry *dir,
struct dentry *rep,
bool preemptive)
bool preemptive,
enum fscache_why_object_killed why)
{
struct dentry *grave, *trap;
struct path path, path_to_graveyard;
@ -289,7 +292,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
ret = vfs_unlink(d_inode(dir), rep, NULL);
if (preemptive)
cachefiles_mark_object_buried(cache, rep);
cachefiles_mark_object_buried(cache, rep, why);
}
mutex_unlock(&d_inode(dir)->i_mutex);
@ -394,7 +397,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
"Rename failed with error %d", ret);
if (preemptive)
cachefiles_mark_object_buried(cache, rep);
cachefiles_mark_object_buried(cache, rep, why);
}
unlock_rename(cache->graveyard, dir);
@ -422,7 +425,7 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,
mutex_lock_nested(&d_inode(dir)->i_mutex, I_MUTEX_PARENT);
if (test_bit(CACHEFILES_OBJECT_BURIED, &object->flags)) {
if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) {
/* object allocation for the same key preemptively deleted this
* object's file so that it could create its own file */
_debug("object preemptively buried");
@ -433,7 +436,8 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,
* may have been renamed */
if (dir == object->dentry->d_parent) {
ret = cachefiles_bury_object(cache, dir,
object->dentry, false);
object->dentry, false,
FSCACHE_OBJECT_WAS_RETIRED);
} else {
/* it got moved, presumably by cachefilesd culling it,
* so it's no longer in the key path and we can ignore
@ -522,7 +526,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
if (d_is_negative(next)) {
ret = cachefiles_has_space(cache, 1, 0);
if (ret < 0)
goto create_error;
goto no_space_error;
path.dentry = dir;
ret = security_path_mkdir(&path, next, 0);
@ -551,7 +555,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
if (d_is_negative(next)) {
ret = cachefiles_has_space(cache, 1, 0);
if (ret < 0)
goto create_error;
goto no_space_error;
path.dentry = dir;
ret = security_path_mknod(&path, next, S_IFREG, 0);
@ -602,7 +606,8 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
* mutex) */
object->dentry = NULL;
ret = cachefiles_bury_object(cache, dir, next, true);
ret = cachefiles_bury_object(cache, dir, next, true,
FSCACHE_OBJECT_IS_STALE);
dput(next);
next = NULL;
@ -610,6 +615,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
goto delete_error;
_debug("redo lookup");
fscache_object_retrying_stale(&object->fscache);
goto lookup_again;
}
}
@ -662,6 +668,8 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
_leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino);
return 0;
no_space_error:
fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE);
create_error:
_debug("create error %d", ret);
if (ret == -EIO)
@ -927,7 +935,8 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
/* actually remove the victim (drops the dir mutex) */
_debug("bury");
ret = cachefiles_bury_object(cache, dir, victim, false);
ret = cachefiles_bury_object(cache, dir, victim, false,
FSCACHE_OBJECT_WAS_CULLED);
if (ret < 0)
goto error;

8
fs/fscache/cookie.c
View file

@ -327,7 +327,8 @@ static int fscache_alloc_object(struct fscache_cache *cache,
object_already_extant:
ret = -ENOBUFS;
if (fscache_object_is_dead(object)) {
if (fscache_object_is_dying(object) ||
fscache_cache_is_broken(object)) {
spin_unlock(&cookie->lock);
goto error;
}
@ -671,7 +672,7 @@ int __fscache_check_consistency(struct fscache_cookie *cookie)
if (!op)
return -ENOMEM;
fscache_operation_init(op, NULL, NULL);
fscache_operation_init(op, NULL, NULL, NULL);
op->flags = FSCACHE_OP_MYTHREAD |
(1 << FSCACHE_OP_WAITING) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
@ -695,8 +696,7 @@ int __fscache_check_consistency(struct fscache_cookie *cookie)
/* the work queue now carries its own ref on the object */
spin_unlock(&cookie->lock);
ret = fscache_wait_for_operation_activation(object, op,
NULL, NULL, NULL);
ret = fscache_wait_for_operation_activation(object, op, NULL, NULL);
if (ret == 0) {
/* ask the cache to honour the operation */
ret = object->cache->ops->check_consistency(op);

12
fs/fscache/internal.h
View file

@ -124,8 +124,7 @@ extern int fscache_submit_exclusive_op(struct fscache_object *,
struct fscache_operation *);
extern int fscache_submit_op(struct fscache_object *,
struct fscache_operation *);
extern int fscache_cancel_op(struct fscache_operation *,
void (*)(struct fscache_operation *));
extern int fscache_cancel_op(struct fscache_operation *, bool);
extern void fscache_cancel_all_ops(struct fscache_object *);
extern void fscache_abort_object(struct fscache_object *);
extern void fscache_start_operations(struct fscache_object *);
@ -138,8 +137,7 @@ extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
extern int fscache_wait_for_operation_activation(struct fscache_object *,
struct fscache_operation *,
atomic_t *,
atomic_t *,
void (*)(struct fscache_operation *));
atomic_t *);
extern void fscache_invalidate_writes(struct fscache_cookie *);
/*
@ -164,6 +162,7 @@ extern atomic_t fscache_n_op_pend;
extern atomic_t fscache_n_op_run;
extern atomic_t fscache_n_op_enqueue;
extern atomic_t fscache_n_op_deferred_release;
extern atomic_t fscache_n_op_initialised;
extern atomic_t fscache_n_op_release;
extern atomic_t fscache_n_op_gc;
extern atomic_t fscache_n_op_cancelled;
@ -271,6 +270,11 @@ extern atomic_t fscache_n_cop_write_page;
extern atomic_t fscache_n_cop_uncache_page;
extern atomic_t fscache_n_cop_dissociate_pages;
extern atomic_t fscache_n_cache_no_space_reject;
extern atomic_t fscache_n_cache_stale_objects;
extern atomic_t fscache_n_cache_retired_objects;
extern atomic_t fscache_n_cache_culled_objects;
static inline void fscache_stat(atomic_t *stat)
{
atomic_inc(stat);

69
fs/fscache/object.c
View file

@ -327,6 +327,17 @@ void fscache_object_init(struct fscache_object *object,
}
EXPORT_SYMBOL(fscache_object_init);
/*
* Mark the object as no longer being live, making sure that we synchronise
* against op submission.
*/
static inline void fscache_mark_object_dead(struct fscache_object *object)
{
spin_lock(&object->lock);
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
spin_unlock(&object->lock);
}
/*
* Abort object initialisation before we start it.
*/
@ -610,6 +621,8 @@ static const struct fscache_state *fscache_lookup_failure(struct fscache_object
object->cache->ops->lookup_complete(object);
fscache_stat_d(&fscache_n_cop_lookup_complete);
set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags);
cookie = object->cookie;
set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
@ -629,7 +642,7 @@ static const struct fscache_state *fscache_kill_object(struct fscache_object *ob
_enter("{OBJ%x,%d,%d},%d",
object->debug_id, object->n_ops, object->n_children, event);
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
fscache_mark_object_dead(object);
object->oob_event_mask = 0;
if (list_empty(&object->dependents) &&
@ -948,7 +961,8 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj
if (!op)
goto nomem;
fscache_operation_init(op, object->cache->ops->invalidate_object, NULL);
fscache_operation_init(op, object->cache->ops->invalidate_object,
NULL, NULL);
op->flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_EXCLUSIVE) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
@ -974,13 +988,13 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj
return transit_to(UPDATE_OBJECT);
nomem:
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
fscache_mark_object_dead(object);
fscache_unuse_cookie(object);
_leave(" [ENOMEM]");
return transit_to(KILL_OBJECT);
submit_op_failed:
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
fscache_mark_object_dead(object);
spin_unlock(&cookie->lock);
fscache_unuse_cookie(object);
kfree(op);
@ -1016,3 +1030,50 @@ static const struct fscache_state *fscache_update_object(struct fscache_object *
_leave("");
return transit_to(WAIT_FOR_CMD);
}
/**
* fscache_object_retrying_stale - Note retrying stale object
* @object: The object that will be retried
*
* Note that an object lookup found an on-disk object that was adjudged to be
* stale and has been deleted. The lookup will be retried.
*/
void fscache_object_retrying_stale(struct fscache_object *object)
{
fscache_stat(&fscache_n_cache_no_space_reject);
}
EXPORT_SYMBOL(fscache_object_retrying_stale);
/**
* fscache_object_mark_killed - Note that an object was killed
* @object: The object that was culled
* @why: The reason the object was killed.
*
* Note that an object was killed. Returns true if the object was
* already marked killed, false if it wasn't.
*/
void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why)
{
if (test_and_set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags)) {
pr_err("Error: Object already killed by cache [%s]\n",
object->cache->identifier);
return;
}
switch (why) {
case FSCACHE_OBJECT_NO_SPACE:
fscache_stat(&fscache_n_cache_no_space_reject);
break;
case FSCACHE_OBJECT_IS_STALE:
fscache_stat(&fscache_n_cache_stale_objects);
break;
case FSCACHE_OBJECT_WAS_RETIRED:
fscache_stat(&fscache_n_cache_retired_objects);
break;
case FSCACHE_OBJECT_WAS_CULLED:
fscache_stat(&fscache_n_cache_culled_objects);
break;
}
}
EXPORT_SYMBOL(fscache_object_mark_killed);

292
fs/fscache/operation.c
View file

@ -20,6 +20,35 @@
atomic_t fscache_op_debug_id;
EXPORT_SYMBOL(fscache_op_debug_id);
static void fscache_operation_dummy_cancel(struct fscache_operation *op)
{
}
/**
* 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 and processor if needed.
*/
void fscache_operation_init(struct fscache_operation *op,
fscache_operation_processor_t processor,
fscache_operation_cancel_t cancel,
fscache_operation_release_t release)
{
INIT_WORK(&op->work, fscache_op_work_func);
atomic_set(&op->usage, 1);
op->state = FSCACHE_OP_ST_INITIALISED;
op->debug_id = atomic_inc_return(&fscache_op_debug_id);
op->processor = processor;
op->cancel = cancel ?: fscache_operation_dummy_cancel;
op->release = release;
INIT_LIST_HEAD(&op->pend_link);
fscache_stat(&fscache_n_op_initialised);
}
EXPORT_SYMBOL(fscache_operation_init);
/**
* fscache_enqueue_operation - Enqueue an operation for processing
* @op: The operation to enqueue
@ -75,69 +104,6 @@ static void fscache_run_op(struct fscache_object *object,
fscache_stat(&fscache_n_op_run);
}
/*
* submit an exclusive operation for an object
* - other ops are excluded from running simultaneously with this one
* - this gets any extra refs it needs on an op
*/
int fscache_submit_exclusive_op(struct fscache_object *object,
struct fscache_operation *op)
{
int ret;
_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
ASSERTCMP(object->n_ops, >=, object->n_in_progress);
ASSERTCMP(object->n_ops, >=, object->n_exclusive);
ASSERT(list_empty(&op->pend_link));
op->state = FSCACHE_OP_ST_PENDING;
if (fscache_object_is_active(object)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
if (object->n_in_progress > 0) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
} else if (!list_empty(&object->pending_ops)) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
fscache_start_operations(object);
} else {
ASSERTCMP(object->n_in_progress, ==, 0);
fscache_run_op(object, op);
}
/* need to issue a new write op after this */
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
ret = 0;
} else if (test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else {
/* If we're in any other state, there must have been an I/O
* error of some nature.
*/
ASSERT(test_bit(FSCACHE_IOERROR, &object->cache->flags));
ret = -EIO;
}
spin_unlock(&object->lock);
return ret;
}
/*
* report an unexpected submission
*/
@ -175,6 +141,87 @@ static void fscache_report_unexpected_submission(struct fscache_object *object,
dump_stack();
}
/*
* submit an exclusive operation for an object
* - other ops are excluded from running simultaneously with this one
* - this gets any extra refs it needs on an op
*/
int fscache_submit_exclusive_op(struct fscache_object *object,
struct fscache_operation *op)
{
const struct fscache_state *ostate;
unsigned long flags;
int ret;
_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
ASSERTCMP(object->n_ops, >=, object->n_in_progress);
ASSERTCMP(object->n_ops, >=, object->n_exclusive);
ASSERT(list_empty(&op->pend_link));
ostate = object->state;
smp_rmb();
op->state = FSCACHE_OP_ST_PENDING;
flags = READ_ONCE(object->flags);
if (unlikely(!(flags & BIT(FSCACHE_OBJECT_IS_LIVE)))) {
fscache_stat(&fscache_n_op_rejected);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (unlikely(fscache_cache_is_broken(object))) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -EIO;
} else if (flags & BIT(FSCACHE_OBJECT_IS_AVAILABLE)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
if (object->n_in_progress > 0) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
} else if (!list_empty(&object->pending_ops)) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
fscache_start_operations(object);
} else {
ASSERTCMP(object->n_in_progress, ==, 0);
fscache_run_op(object, op);
}
/* need to issue a new write op after this */
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_IS_LOOKED_UP)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else {
fscache_report_unexpected_submission(object, op, ostate);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
}
spin_unlock(&object->lock);
return ret;
}
/*
* submit an operation for an object
* - objects may be submitted only in the following states:
@ -187,6 +234,7 @@ int fscache_submit_op(struct fscache_object *object,
struct fscache_operation *op)
{
const struct fscache_state *ostate;
unsigned long flags;
int ret;
_enter("{OBJ%x OP%x},{%u}",
@ -204,7 +252,17 @@ int fscache_submit_op(struct fscache_object *object,
smp_rmb();
op->state = FSCACHE_OP_ST_PENDING;
if (fscache_object_is_active(object)) {
flags = READ_ONCE(object->flags);
if (unlikely(!(flags & BIT(FSCACHE_OBJECT_IS_LIVE)))) {
fscache_stat(&fscache_n_op_rejected);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (unlikely(fscache_cache_is_broken(object))) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -EIO;
} else if (flags & BIT(FSCACHE_OBJECT_IS_AVAILABLE)) {
op->object = object;
object->n_ops++;
@ -222,23 +280,21 @@ int fscache_submit_op(struct fscache_object *object,
fscache_run_op(object, op);
}
ret = 0;
} else if (test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
} else if (flags & BIT(FSCACHE_OBJECT_IS_LOOKED_UP)) {
op->object = object;
object->n_ops++;
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else if (fscache_object_is_dying(object)) {
fscache_stat(&fscache_n_op_rejected);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (!test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
fscache_report_unexpected_submission(object, op, ostate);
ASSERT(!fscache_object_is_active(object));
} else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else {
fscache_report_unexpected_submission(object, op, ostate);
ASSERT(!fscache_object_is_active(object));
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
}
@ -293,9 +349,10 @@ void fscache_start_operations(struct fscache_object *object)
* cancel an operation that's pending on an object
*/
int fscache_cancel_op(struct fscache_operation *op,
void (*do_cancel)(struct fscache_operation *))
bool cancel_in_progress_op)
{
struct fscache_object *object = op->object;
bool put = false;
int ret;
_enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
@ -309,19 +366,37 @@ int fscache_cancel_op(struct fscache_operation *op,
ret = -EBUSY;
if (op->state == FSCACHE_OP_ST_PENDING) {
ASSERT(!list_empty(&op->pend_link));
fscache_stat(&fscache_n_op_cancelled);
list_del_init(&op->pend_link);
if (do_cancel)
do_cancel(op);
put = true;
fscache_stat(&fscache_n_op_cancelled);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
ret = 0;
} else if (op->state == FSCACHE_OP_ST_IN_PROGRESS && cancel_in_progress_op) {
ASSERTCMP(object->n_in_progress, >, 0);
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
object->n_in_progress--;
if (object->n_in_progress == 0)
fscache_start_operations(object);
fscache_stat(&fscache_n_op_cancelled);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
fscache_put_operation(op);
ret = 0;
}
if (put)
fscache_put_operation(op);
spin_unlock(&object->lock);
_leave(" = %d", ret);
return ret;
@ -345,6 +420,7 @@ void fscache_cancel_all_ops(struct fscache_object *object)
list_del_init(&op->pend_link);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
@ -377,8 +453,12 @@ void fscache_op_complete(struct fscache_operation *op, bool cancelled)
spin_lock(&object->lock);
op->state = cancelled ?
FSCACHE_OP_ST_CANCELLED : FSCACHE_OP_ST_COMPLETE;
if (!cancelled) {
op->state = FSCACHE_OP_ST_COMPLETE;
} else {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
}
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
@ -409,9 +489,9 @@ void fscache_put_operation(struct fscache_operation *op)
return;
_debug("PUT OP");
ASSERTIFCMP(op->state != FSCACHE_OP_ST_COMPLETE,
ASSERTIFCMP(op->state != FSCACHE_OP_ST_INITIALISED &&
op->state != FSCACHE_OP_ST_COMPLETE,
op->state, ==, FSCACHE_OP_ST_CANCELLED);
op->state = FSCACHE_OP_ST_DEAD;
fscache_stat(&fscache_n_op_release);
@ -419,37 +499,39 @@ void fscache_put_operation(struct fscache_operation *op)
op->release(op);
op->release = NULL;
}
op->state = FSCACHE_OP_ST_DEAD;
object = op->object;
if (likely(object)) {
if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
atomic_dec(&object->n_reads);
if (test_bit(FSCACHE_OP_UNUSE_COOKIE, &op->flags))
fscache_unuse_cookie(object);
if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
atomic_dec(&object->n_reads);
if (test_bit(FSCACHE_OP_UNUSE_COOKIE, &op->flags))
fscache_unuse_cookie(object);
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
* lock, and defer it otherwise */
if (!spin_trylock(&object->lock)) {
_debug("defer put");
fscache_stat(&fscache_n_op_deferred_release);
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
* lock, and defer it otherwise */
if (!spin_trylock(&object->lock)) {
_debug("defer put");
fscache_stat(&fscache_n_op_deferred_release);
cache = object->cache;
spin_lock(&cache->op_gc_list_lock);
list_add_tail(&op->pend_link, &cache->op_gc_list);
spin_unlock(&cache->op_gc_list_lock);
schedule_work(&cache->op_gc);
_leave(" [defer]");
return;
}
cache = object->cache;
spin_lock(&cache->op_gc_list_lock);
list_add_tail(&op->pend_link, &cache->op_gc_list);
spin_unlock(&cache->op_gc_list_lock);
schedule_work(&cache->op_gc);
_leave(" [defer]");
return;
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
if (object->n_ops == 0)
fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&object->lock);
}
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
if (object->n_ops == 0)
fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&object->lock);
kfree(op);
_leave(" [done]");
}

86
fs/fscache/page.c
View file

@ -213,7 +213,7 @@ int __fscache_attr_changed(struct fscache_cookie *cookie)
return -ENOMEM;
}
fscache_operation_init(op, fscache_attr_changed_op, NULL);
fscache_operation_init(op, fscache_attr_changed_op, NULL, NULL);
op->flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_EXCLUSIVE) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
@ -239,7 +239,7 @@ int __fscache_attr_changed(struct fscache_cookie *cookie)
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs:
spin_unlock(&cookie->lock);
kfree(op);
fscache_put_operation(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
fscache_stat(&fscache_n_attr_changed_nobufs);
@ -248,6 +248,17 @@ int __fscache_attr_changed(struct fscache_cookie *cookie)
}
EXPORT_SYMBOL(__fscache_attr_changed);
/*
* Handle cancellation of a pending retrieval op
*/
static void fscache_do_cancel_retrieval(struct fscache_operation *_op)
{
struct fscache_retrieval *op =
container_of(_op, struct fscache_retrieval, op);
atomic_set(&op->n_pages, 0);
}
/*
* release a retrieval op reference
*/
@ -258,11 +269,12 @@ static void fscache_release_retrieval_op(struct fscache_operation *_op)
_enter("{OP%x}", op->op.debug_id);
ASSERTCMP(atomic_read(&op->n_pages), ==, 0);
ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED,
atomic_read(&op->n_pages), ==, 0);
fscache_hist(fscache_retrieval_histogram, op->start_time);
if (op->context)
fscache_put_context(op->op.object->cookie, op->context);
fscache_put_context(op->cookie, op->context);
_leave("");
}
@ -285,15 +297,24 @@ static struct fscache_retrieval *fscache_alloc_retrieval(
return NULL;
}
fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op);
fscache_operation_init(&op->op, NULL,
fscache_do_cancel_retrieval,
fscache_release_retrieval_op);
op->op.flags = FSCACHE_OP_MYTHREAD |
(1UL << FSCACHE_OP_WAITING) |
(1UL << FSCACHE_OP_UNUSE_COOKIE);
op->cookie = cookie;
op->mapping = mapping;
op->end_io_func = end_io_func;
op->context = context;
op->start_time = jiffies;
INIT_LIST_HEAD(&op->to_do);
/* Pin the netfs read context in case we need to do the actual netfs
* read because we've encountered a cache read failure.
*/
if (context)
fscache_get_context(op->cookie, context);
return op;
}
@ -329,25 +350,13 @@ int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
return 0;
}
/*
* Handle cancellation of a pending retrieval op
*/
static void fscache_do_cancel_retrieval(struct fscache_operation *_op)
{
struct fscache_retrieval *op =
container_of(_op, struct fscache_retrieval, op);
atomic_set(&op->n_pages, 0);
}
/*
* wait for an object to become active (or dead)
*/
int fscache_wait_for_operation_activation(struct fscache_object *object,
struct fscache_operation *op,
atomic_t *stat_op_waits,
atomic_t *stat_object_dead,
void (*do_cancel)(struct fscache_operation *))
atomic_t *stat_object_dead)
{
int ret;
@ -359,7 +368,7 @@ int fscache_wait_for_operation_activation(struct fscache_object *object,
fscache_stat(stat_op_waits);
if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
TASK_INTERRUPTIBLE) != 0) {
ret = fscache_cancel_op(op, do_cancel);
ret = fscache_cancel_op(op, false);
if (ret == 0)
return -ERESTARTSYS;
@ -377,11 +386,13 @@ int fscache_wait_for_operation_activation(struct fscache_object *object,
_leave(" = -ENOBUFS [cancelled]");
return -ENOBUFS;
}
if (unlikely(fscache_object_is_dead(object))) {
pr_err("%s() = -ENOBUFS [obj dead %d]\n", __func__, op->state);
fscache_cancel_op(op, do_cancel);
if (unlikely(fscache_object_is_dying(object) ||
fscache_cache_is_broken(object))) {
enum fscache_operation_state state = op->state;
fscache_cancel_op(op, true);
if (stat_object_dead)
fscache_stat(stat_object_dead);
_leave(" = -ENOBUFS [obj dead %d]", state);
return -ENOBUFS;
}
return 0;
@ -453,17 +464,12 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
fscache_stat(&fscache_n_retrieval_ops);
/* pin the netfs read context in case we need to do the actual netfs
* read because we've encountered a cache read failure */
fscache_get_context(object->cookie, op->context);
/* we wait for the operation to become active, and then process it
* *here*, in this thread, and not in the thread pool */
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_retrieval_op_waits),
__fscache_stat(&fscache_n_retrievals_object_dead),
fscache_do_cancel_retrieval);
__fscache_stat(&fscache_n_retrievals_object_dead));
if (ret < 0)
goto error;
@ -503,7 +509,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
spin_unlock(&cookie->lock);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
kfree(op);
fscache_put_retrieval(op);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
_leave(" = -ENOBUFS");
@ -584,17 +590,12 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
fscache_stat(&fscache_n_retrieval_ops);
/* pin the netfs read context in case we need to do the actual netfs
* read because we've encountered a cache read failure */
fscache_get_context(object->cookie, op->context);
/* we wait for the operation to become active, and then process it
* *here*, in this thread, and not in the thread pool */
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_retrieval_op_waits),
__fscache_stat(&fscache_n_retrievals_object_dead),
fscache_do_cancel_retrieval);
__fscache_stat(&fscache_n_retrievals_object_dead));
if (ret < 0)
goto error;
@ -632,7 +633,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
kfree(op);
fscache_put_retrieval(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
nobufs:
@ -700,8 +701,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_alloc_op_waits),
__fscache_stat(&fscache_n_allocs_object_dead),
fscache_do_cancel_retrieval);
__fscache_stat(&fscache_n_allocs_object_dead));
if (ret < 0)
goto error;
@ -726,7 +726,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
kfree(op);
fscache_put_retrieval(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
nobufs:
@ -944,7 +944,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
if (!op)
goto nomem;
fscache_operation_init(&op->op, fscache_write_op,
fscache_operation_init(&op->op, fscache_write_op, NULL,
fscache_release_write_op);
op->op.flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_WAITING) |
@ -1016,7 +1016,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
spin_unlock(&object->lock);
spin_unlock(&cookie->lock);
radix_tree_preload_end();
kfree(op);
fscache_put_operation(&op->op);
fscache_stat(&fscache_n_stores_ok);
_leave(" = 0");
return 0;
@ -1036,7 +1036,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
nobufs:
spin_unlock(&cookie->lock);
radix_tree_preload_end();
kfree(op);
fscache_put_operation(&op->op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
fscache_stat(&fscache_n_stores_nobufs);
@ -1044,7 +1044,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
return -ENOBUFS;
nomem_free:
kfree(op);
fscache_put_operation(&op->op);
nomem:
fscache_stat(&fscache_n_stores_oom);
_leave(" = -ENOMEM");

14
fs/fscache/stats.c
View file

@ -23,6 +23,7 @@ atomic_t fscache_n_op_run;
atomic_t fscache_n_op_enqueue;
atomic_t fscache_n_op_requeue;
atomic_t fscache_n_op_deferred_release;
atomic_t fscache_n_op_initialised;
atomic_t fscache_n_op_release;
atomic_t fscache_n_op_gc;
atomic_t fscache_n_op_cancelled;
@ -130,6 +131,11 @@ atomic_t fscache_n_cop_write_page;
atomic_t fscache_n_cop_uncache_page;
atomic_t fscache_n_cop_dissociate_pages;
atomic_t fscache_n_cache_no_space_reject;
atomic_t fscache_n_cache_stale_objects;
atomic_t fscache_n_cache_retired_objects;
atomic_t fscache_n_cache_culled_objects;
/*
* display the general statistics
*/
@ -246,7 +252,8 @@ static int fscache_stats_show(struct seq_file *m, void *v)
atomic_read(&fscache_n_op_enqueue),
atomic_read(&fscache_n_op_cancelled),
atomic_read(&fscache_n_op_rejected));
seq_printf(m, "Ops : dfr=%u rel=%u gc=%u\n",
seq_printf(m, "Ops : ini=%u dfr=%u rel=%u gc=%u\n",
atomic_read(&fscache_n_op_initialised),
atomic_read(&fscache_n_op_deferred_release),
atomic_read(&fscache_n_op_release),
atomic_read(&fscache_n_op_gc));
@ -271,6 +278,11 @@ static int fscache_stats_show(struct seq_file *m, void *v)
atomic_read(&fscache_n_cop_write_page),
atomic_read(&fscache_n_cop_uncache_page),
atomic_read(&fscache_n_cop_dissociate_pages));
seq_printf(m, "CacheEv: nsp=%d stl=%d rtr=%d cul=%d\n",
atomic_read(&fscache_n_cache_no_space_reject),
atomic_read(&fscache_n_cache_stale_objects),
atomic_read(&fscache_n_cache_retired_objects),
atomic_read(&fscache_n_cache_culled_objects));
return 0;
}

55
include/linux/fscache-cache.h
View file

@ -74,6 +74,7 @@ extern wait_queue_head_t fscache_cache_cleared_wq;
*/
typedef void (*fscache_operation_release_t)(struct fscache_operation *op);
typedef void (*fscache_operation_processor_t)(struct fscache_operation *op);
typedef void (*fscache_operation_cancel_t)(struct fscache_operation *op);
enum fscache_operation_state {
FSCACHE_OP_ST_BLANK, /* Op is not yet submitted */
@ -109,6 +110,9 @@ struct fscache_operation {
* the op in a non-pool thread */
fscache_operation_processor_t processor;
/* Operation cancellation cleanup (optional) */
fscache_operation_cancel_t cancel;
/* operation releaser */
fscache_operation_release_t release;
};
@ -119,33 +123,17 @@ extern void fscache_op_work_func(struct work_struct *work);
extern void fscache_enqueue_operation(struct fscache_operation *);
extern void fscache_op_complete(struct fscache_operation *, bool);
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 and processor if needed.
*/
static inline void fscache_operation_init(struct fscache_operation *op,
fscache_operation_processor_t processor,
fscache_operation_release_t release)
{
INIT_WORK(&op->work, fscache_op_work_func);
atomic_set(&op->usage, 1);
op->state = FSCACHE_OP_ST_INITIALISED;
op->debug_id = atomic_inc_return(&fscache_op_debug_id);
op->processor = processor;
op->release = release;
INIT_LIST_HEAD(&op->pend_link);
}
extern void fscache_operation_init(struct fscache_operation *,
fscache_operation_processor_t,
fscache_operation_cancel_t,
fscache_operation_release_t);
/*
* data read operation
*/
struct fscache_retrieval {
struct fscache_operation op;
struct fscache_cookie *cookie; /* The netfs cookie */
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) */
@ -371,6 +359,7 @@ struct fscache_object {
#define FSCACHE_OBJECT_IS_LOOKED_UP 4 /* T if object has been looked up */
#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */
#define FSCACHE_OBJECT_RETIRED 6 /* T if object was retired on relinquishment */
#define FSCACHE_OBJECT_KILLED_BY_CACHE 7 /* T if object was killed by the cache */
struct list_head cache_link; /* link in cache->object_list */
struct hlist_node cookie_link; /* link in cookie->backing_objects */
@ -410,17 +399,16 @@ static inline bool fscache_object_is_available(struct fscache_object *object)
return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
}
static inline bool fscache_cache_is_broken(struct fscache_object *object)
{
return test_bit(FSCACHE_IOERROR, &object->cache->flags);
}
static inline bool fscache_object_is_active(struct fscache_object *object)
{
return fscache_object_is_available(object) &&
fscache_object_is_live(object) &&
!test_bit(FSCACHE_IOERROR, &object->cache->flags);
}
static inline bool fscache_object_is_dead(struct fscache_object *object)
{
return fscache_object_is_dying(object) &&
test_bit(FSCACHE_IOERROR, &object->cache->flags);
!fscache_cache_is_broken(object);
}
/**
@ -551,4 +539,15 @@ extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data,
uint16_t datalen);
extern void fscache_object_retrying_stale(struct fscache_object *object);
enum fscache_why_object_killed {
FSCACHE_OBJECT_IS_STALE,
FSCACHE_OBJECT_NO_SPACE,
FSCACHE_OBJECT_WAS_RETIRED,
FSCACHE_OBJECT_WAS_CULLED,
};
extern void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why);
#endif /* _LINUX_FSCACHE_CACHE_H */