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FS-Cache: Wrap checks on object state
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Wrap checks on object state (mostly outside of fs/fscache/object.c) with
inline functions so that the mechanism can be replaced.

Some of the state checks within object.c are left as-is as they will be
replaced.

Signed-off-by: David Howells <[email protected]>
Tested-By: Milosz Tanski <[email protected]>
Acked-by: Jeff Layton <[email protected]>
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dhowells committed Jun 19, 2013
1 parent 610be24 commit 493f7bc
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Showing 6 changed files with 40 additions and 21 deletions.
4 changes: 2 additions & 2 deletions fs/cachefiles/namei.c
Original file line number Diff line number Diff line change
Expand Up @@ -130,7 +130,7 @@ static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
fscache_object_states[object->fscache.state],
dentry);

if (object->fscache.state < FSCACHE_OBJECT_DYING) {
if (fscache_object_is_live(&object->fscache)) {
printk(KERN_ERR "\n");
printk(KERN_ERR "CacheFiles: Error:"
" Can't preemptively bury live object\n");
Expand Down Expand Up @@ -192,7 +192,7 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
/* an old object from a previous incarnation is hogging the slot - we
* need to wait for it to be destroyed */
wait_for_old_object:
if (xobject->fscache.state < FSCACHE_OBJECT_DYING) {
if (fscache_object_is_live(&object->fscache)) {
printk(KERN_ERR "\n");
printk(KERN_ERR "CacheFiles: Error:"
" Unexpected object collision\n");
Expand Down
2 changes: 1 addition & 1 deletion fs/fscache/cache.c
Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,7 @@ struct fscache_cache *fscache_select_cache_for_object(
struct fscache_object, cookie_link);

cache = object->cache;
if (object->state >= FSCACHE_OBJECT_DYING ||
if (fscache_object_is_dying(object) ||
test_bit(FSCACHE_IOERROR, &cache->flags))
cache = NULL;

Expand Down
8 changes: 4 additions & 4 deletions fs/fscache/cookie.c
Original file line number Diff line number Diff line change
Expand Up @@ -285,7 +285,7 @@ static int fscache_alloc_object(struct fscache_cache *cache,

object_already_extant:
ret = -ENOBUFS;
if (object->state >= FSCACHE_OBJECT_DYING) {
if (fscache_object_is_dead(object)) {
spin_unlock(&cookie->lock);
goto error;
}
Expand Down Expand Up @@ -321,7 +321,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
ret = -EEXIST;
hlist_for_each_entry(p, &cookie->backing_objects, cookie_link) {
if (p->cache == object->cache) {
if (p->state >= FSCACHE_OBJECT_DYING)
if (fscache_object_is_dying(p))
ret = -ENOBUFS;
goto cant_attach_object;
}
Expand All @@ -332,7 +332,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
hlist_for_each_entry(p, &cookie->parent->backing_objects,
cookie_link) {
if (p->cache == object->cache) {
if (p->state >= FSCACHE_OBJECT_DYING) {
if (fscache_object_is_dying(p)) {
ret = -ENOBUFS;
spin_unlock(&cookie->parent->lock);
goto cant_attach_object;
Expand Down Expand Up @@ -400,7 +400,7 @@ void __fscache_invalidate(struct fscache_cookie *cookie)
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object,
cookie_link);
if (object->state < FSCACHE_OBJECT_DYING)
if (fscache_object_is_live(object))
fscache_raise_event(
object, FSCACHE_OBJECT_EV_INVALIDATE);
}
Expand Down
8 changes: 4 additions & 4 deletions fs/fscache/object.c
Original file line number Diff line number Diff line change
Expand Up @@ -457,10 +457,10 @@ static void fscache_initialise_object(struct fscache_object *object)
spin_lock_nested(&parent->lock, 1);
_debug("parent %s", fscache_object_states[parent->state]);

if (parent->state >= FSCACHE_OBJECT_DYING) {
if (fscache_object_is_dying(parent)) {
_debug("bad parent");
set_bit(FSCACHE_OBJECT_EV_WITHDRAW, &object->events);
} else if (parent->state < FSCACHE_OBJECT_AVAILABLE) {
} else if (!fscache_object_is_available(parent)) {
_debug("wait");

/* we may get woken up in this state by child objects
Expand Down Expand Up @@ -517,9 +517,9 @@ static void fscache_lookup_object(struct fscache_object *object)
ASSERTCMP(parent->n_obj_ops, >, 0);

/* make sure the parent is still available */
ASSERTCMP(parent->state, >=, FSCACHE_OBJECT_AVAILABLE);
ASSERT(fscache_object_is_available(parent));

if (parent->state >= FSCACHE_OBJECT_DYING ||
if (fscache_object_is_dying(parent) ||
test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
_debug("unavailable");
set_bit(FSCACHE_OBJECT_EV_WITHDRAW, &object->events);
Expand Down
2 changes: 1 addition & 1 deletion fs/fscache/operation.c
Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,7 @@ void fscache_enqueue_operation(struct fscache_operation *op)

ASSERT(list_empty(&op->pend_link));
ASSERT(op->processor != NULL);
ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
ASSERT(fscache_object_is_available(op->object));
ASSERTCMP(atomic_read(&op->usage), >, 0);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_IN_PROGRESS);

Expand Down
37 changes: 28 additions & 9 deletions include/linux/fscache-cache.h
Original file line number Diff line number Diff line change
Expand Up @@ -417,15 +417,6 @@ struct fscache_object {

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)

#define fscache_object_is_dead(obj) \
(test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) && \
(obj)->state >= FSCACHE_OBJECT_DYING)

extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
struct fscache_cache *);

Expand All @@ -438,6 +429,34 @@ extern void fscache_object_destroy(struct fscache_object *object);
#define fscache_object_destroy(object) do {} while(0)
#endif

static inline bool fscache_object_is_live(struct fscache_object *object)
{
return object->state < FSCACHE_OBJECT_DYING;
}

static inline bool fscache_object_is_dying(struct fscache_object *object)
{
return !fscache_object_is_live(object);
}

static inline bool fscache_object_is_available(struct fscache_object *object)
{
return object->state >= FSCACHE_OBJECT_AVAILABLE;
}

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_object_destroyed - Note destruction of an object in a cache
* @cache: The cache from which the object came
Expand Down

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