Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 221c4c7..3579afb 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1649,7 +1649,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
        p->max = 0;
        swap_map = p->swap_map;
        p->swap_map = NULL;
-       p->flags = 0;
        spin_unlock(&swap_lock);
        mutex_unlock(&swapon_mutex);
        vfree(swap_map);
@@ -1667,6 +1666,16 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
                mutex_unlock(&inode->i_mutex);
        }
        filp_close(swap_file, NULL);
+
+       /*
+        * Clear the SWP_USED flag after all resources are freed so that swapon
+        * can reuse this swap_info in alloc_swap_info() safely.  It is ok to
+        * not hold p->lock after we cleared its SWP_WRITEOK.
+        */
+       spin_lock(&swap_lock);
+       p->flags = 0;
+       spin_unlock(&swap_lock);
+
        err = 0;
        atomic_inc(&proc_poll_event);
        wake_up_interruptible(&proc_poll_wait);