diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-12-03 23:10:32 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-12-09 19:08:41 +0300 |
| commit | 0f9368b5bf6db0c04afc5454b1be79022a681615 (patch) | |
| tree | 9744569b45cfca2a30e6e99a5198e4ec2bbeb587 /kernel/locking | |
| parent | 34816d20f173a90389c8a7e641166d8ea9dce70a (diff) | |
| download | linux-0f9368b5bf6db0c04afc5454b1be79022a681615.tar.xz | |
rwsem: Implement down_read_killable_nested
In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_killable_nested. This is needed so that kcmp_lock
can be converted from working on a mutexes to working on rw_semaphores.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/rwsem.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index f11b9bd3431d..54d11cb97551 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1605,6 +1605,20 @@ void down_read_nested(struct rw_semaphore *sem, int subclass) } EXPORT_SYMBOL(down_read_nested); +int down_read_killable_nested(struct rw_semaphore *sem, int subclass) +{ + might_sleep(); + rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_); + + if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) { + rwsem_release(&sem->dep_map, _RET_IP_); + return -EINTR; + } + + return 0; +} +EXPORT_SYMBOL(down_read_killable_nested); + void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) { might_sleep(); |