From 887bddfa90c79957d61067cd54a10087be0c8b23 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 26 May 2016 00:04:58 -0400 Subject: [PATCH] add down_write_killable_nested() Signed-off-by: Al Viro --- include/linux/rwsem.h | 2 ++ kernel/locking/rwsem.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index d1c12d160ace..d37fbb34d06f 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -156,6 +156,7 @@ extern void downgrade_write(struct rw_semaphore *sem); */ extern void down_read_nested(struct rw_semaphore *sem, int subclass); extern void down_write_nested(struct rw_semaphore *sem, int subclass); +extern int down_write_killable_nested(struct rw_semaphore *sem, int subclass); extern void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest_lock); # define down_write_nest_lock(sem, nest_lock) \ @@ -176,6 +177,7 @@ extern void up_read_non_owner(struct rw_semaphore *sem); # define down_read_nested(sem, subclass) down_read(sem) # define down_write_nest_lock(sem, nest_lock) down_write(sem) # define down_write_nested(sem, subclass) down_write(sem) +# define down_write_killable_nested(sem, subclass) down_write_killable(sem) # define down_read_non_owner(sem) down_read(sem) # define up_read_non_owner(sem) up_read(sem) #endif diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index c817216c1615..2e853ad93a3a 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -173,6 +173,22 @@ void down_write_nested(struct rw_semaphore *sem, int subclass) EXPORT_SYMBOL(down_write_nested); +int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) +{ + might_sleep(); + rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_); + + if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + return -EINTR; + } + + rwsem_set_owner(sem); + return 0; +} + +EXPORT_SYMBOL(down_write_killable_nested); + void up_read_non_owner(struct rw_semaphore *sem) { __up_read(sem);