1 files changed, 7 insertions, 0 deletions

diff --git a/fs/fcntl.c b/fs/fcntl.c
index ac4f7db9f134..549daf8005fb 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -19,6 +19,7 @@
 #include <linux/signal.h>
 #include <linux/rcupdate.h>
 #include <linux/pid_namespace.h>
+#include <linux/smp_lock.h>
 
 #include <asm/poll.h>
 #include <asm/siginfo.h>
@@ -175,6 +176,11 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
         if (error)
                 return error;
 
+        /*
+         * We still need a lock here for now to keep multiple FASYNC calls
+         * from racing with each other.
+         */
+        lock_kernel();
         if ((arg ^ filp->f_flags) & FASYNC) {
                 if (filp->f_op && filp->f_op->fasync) {
                         error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
@@ -185,6 +191,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 
         filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
  out:
+        unlock_kernel();
         return error;
 }