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authorAl Viro <viro@zeniv.linux.org.uk>2016-05-26 00:04:58 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2016-05-26 00:04:58 -0400
commit887bddfa90c79957d61067cd54a10087be0c8b23 (patch)
treee4e4c24ee40d721196113df16d5d250bd1e8beac
parentd42b386834ee1c22f6fac2f856bba8a6e4de38bb (diff)
downloadlinux-sh-887bddfa90c79957d61067cd54a10087be0c8b23.tar.gz
add down_write_killable_nested()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--include/linux/rwsem.h2
-rw-r--r--kernel/locking/rwsem.c16
2 files changed, 18 insertions, 0 deletions
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);