NFS: Throttle page dirtying while we're flushing to disk

[safe/jmp/linux-2.6] / fs / nfs / file.c

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 90f292b..404c19c 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -354,6 +354,15 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
                file->f_path.dentry->d_name.name,
                mapping->host->i_ino, len, (long long) pos);
 
+       /*
+        * Prevent starvation issues if someone is doing a consistency
+        * sync-to-disk
+        */
+       ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
+                       nfs_wait_bit_killable, TASK_KILLABLE);
+       if (ret)
+               return ret;
+
        page = grab_cache_page_write_begin(mapping, index, flags);
        if (!page)
                return -ENOMEM;