nfs: don't sleep with inode lock in lock_and_join_requests

[cascardo/linux.git] / fs / nfs / pagelist.c

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 30c9626..4ec67f8 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -167,6 +167,23 @@ nfs_page_group_lock(struct nfs_page *req, bool nonblock)
        return -EAGAIN;
 }
 
+/*
+ * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it
+ * @req - a request in the group
+ *
+ * This is a blocking call to wait for the group lock to be cleared.
+ */
+void
+nfs_page_group_lock_wait(struct nfs_page *req)
+{
+       struct nfs_page *head = req->wb_head;
+
+       WARN_ON_ONCE(head != head->wb_head);
+
+       wait_on_bit(&head->wb_flags, PG_HEADLOCK,
+               TASK_UNINTERRUPTIBLE);
+}
+
 /*
  * nfs_page_group_unlock - unlock the head of the page group
  * @req - request in group that is to be unlocked