eCryptfs: Flush file in vma close

Dirty pages weren't being written back when an mmap'ed eCryptfs file was
closed before the mapping was unmapped. Since f_ops->flush() is not
called by the munmap() path, the lower file was simply being released.
This patch flushes the eCryptfs file in the vm_ops->close() path.

https://launchpad.net/bugs/870326

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: stable@kernel.org [2.6.39+]

1 files changed, 22 insertions, 1 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index c6ac98cf9baa..d3f95f941c47 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -139,6 +139,27 @@ out:
         return rc;
 }
 
+static void ecryptfs_vma_close(struct vm_area_struct *vma)
+{
+        filemap_write_and_wait(vma->vm_file->f_mapping);
+}
+
+static const struct vm_operations_struct ecryptfs_file_vm_ops = {
+        .close          = ecryptfs_vma_close,
+        .fault          = filemap_fault,
+};
+
+static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+        int rc;
+
+        rc = generic_file_mmap(file, vma);
+        if (!rc)
+                vma->vm_ops = &ecryptfs_file_vm_ops;
+
+        return rc;
+}
+
 struct kmem_cache *ecryptfs_file_info_cache;
 
 /**
@@ -349,7 +370,7 @@ const struct file_operations ecryptfs_main_fops = {
 #ifdef CONFIG_COMPAT
         .compat_ioctl = ecryptfs_compat_ioctl,
 #endif
-        .mmap = generic_file_mmap,
+        .mmap = ecryptfs_file_mmap,
         .open = ecryptfs_open,
         .flush = ecryptfs_flush,
         .release = ecryptfs_release,