AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-04-06 20:02:33 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

kref: add kref_test_and_get

Browse Source 
Add kref_test_and_get() function, which atomically add a reference only if
refcount is not zero. This prevent to add a reference to an object that is
already being removed.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Jerome Marchand 2011-01-05 16:57:37 +01:00 committed by Jens Axboe
parent a6e8dc46ff
commit e4a683c899
2 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/kref.h
View File

@ -23,6 +23,7 @@ struct kref {
void kref_init(struct kref *kref); void kref_init(struct kref *kref);
void kref_get(struct kref *kref); void kref_get(struct kref *kref);
int kref_test_and_get(struct kref *kref);
int kref_put(struct kref *kref, void (*release) (struct kref *kref)); int kref_put(struct kref *kref, void (*release) (struct kref *kref));
#endif /* _KREF_H_ */ #endif /* _KREF_H_ */

12
lib/kref.c
View File

@ -36,6 +36,18 @@ void kref_get(struct kref *kref)
smp_mb__after_atomic_inc(); smp_mb__after_atomic_inc();
} }
/**
* kref_test_and_get - increment refcount for object only if refcount is not
* zero.
* @kref: object.
*
* Return non-zero if the refcount was incremented, 0 otherwise
*/
int kref_test_and_get(struct kref *kref)
{
return atomic_inc_not_zero(&kref->refcount);
}
/** /**
* kref_put - decrement refcount for object. * kref_put - decrement refcount for object.
* @kref: object. * @kref: object.