Memory shortage can result in inconsistent flocks state

[safe/jmp/linux-2.6] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index efe1aff..6e22c81 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -733,6 +733,15 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
        lock_kernel();
        if (request->fl_flags & FL_ACCESS)
                goto find_conflict;
+
+       if (request->fl_type != F_UNLCK) {
+               error = -ENOMEM;
+               new_fl = locks_alloc_lock();
+               if (new_fl == NULL)
+                       goto out;
+               error = 0;
+       }
+
        for_each_lock(inode, before) {
                struct file_lock *fl = *before;
                if (IS_POSIX(fl))
@@ -754,10 +763,6 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
                goto out;
        }
 
-       error = -ENOMEM;
-       new_fl = locks_alloc_lock();
-       if (new_fl == NULL)
-               goto out;
        /*
         * If a higher-priority process was blocked on the old file lock,
         * give it the opportunity to lock the file.