This will be used to support mshare functionality where the read
lock on an mshare host mm is taken while holding the lock on a
process mm.
Signed-off-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
---
include/linux/mmap_lock.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index 45a21faa3ff6..4671b4435d2a 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -191,6 +191,13 @@ static inline void mmap_read_lock(struct mm_struct *mm)
__mmap_lock_trace_acquire_returned(mm, false, true);
}
+static inline void mmap_read_lock_nested(struct mm_struct *mm, int subclass)
+{
+ __mmap_lock_trace_start_locking(mm, false);
+ down_read_nested(&mm->mmap_lock, subclass);
+ __mmap_lock_trace_acquire_returned(mm, false, true);
+}
+
static inline int mmap_read_lock_killable(struct mm_struct *mm)
{
int ret;
--
2.43.5
