ovl: add ovl_fallocate()

Implement stacked fallocate.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 4c8bf77..58b37fe 100644 (file)
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -286,6 +286,29 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
        return ret;
 }
 
+static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+       struct inode *inode = file_inode(file);
+       struct fd real;
+       const struct cred *old_cred;
+       int ret;
+
+       ret = ovl_real_fdget(file, &real);
+       if (ret)
+               return ret;
+
+       old_cred = ovl_override_creds(file_inode(file)->i_sb);
+       ret = vfs_fallocate(real.file, mode, offset, len);
+       revert_creds(old_cred);
+
+       /* Update size */
+       ovl_copyattr(ovl_inode_real(inode), inode);
+
+       fdput(real);
+
+       return ret;
+}
+
 const struct file_operations ovl_file_operations = {
        .open           = ovl_open,
        .release        = ovl_release,
@@ -294,4 +317,5 @@ const struct file_operations ovl_file_operations = {
        .write_iter     = ovl_write_iter,
        .fsync          = ovl_fsync,
        .mmap           = ovl_mmap,
+       .fallocate      = ovl_fallocate,
 };