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authorAndy Whitcroft <apw@canonical.com>2010-10-01 18:48:02 +0100
committerJohn Rigby <john.rigby@linaro.org>2012-08-15 23:46:02 -0600
commit7b02b15498b202f7fb6f641da4d55e3580277e2d (patch)
tree7ee5afa12bff3dfac8743c4377273d65714de6b7
parentb97da5aff0d3bed75720464a7281ce825f5af794 (diff)
UBUNTU: ubuntu: overlayfs -- overlayfs: add statfs support
Add support for statfs to the overlayfs filesystem. As the upper layer is the target of all write operations assume that the space in that filesystem is the space in the overlayfs. There will be some inaccuracy as overwriting a file will copy it up and consume space we were not expecting, but it is better than nothing. Use the upper layer dentry and mount from the overlayfs root inode, passing the statfs call to that filesystem. Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
-rw-r--r--fs/overlayfs/super.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 02deecdd93e..484753bc6da 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -406,9 +406,29 @@ static int ovl_remount_fs(struct super_block *sb, int *flagsp, char *data)
return mnt_want_write(ufs->upper_mnt);
}
+/**
+ * ovl_statfs
+ * @sb: The overlayfs super block
+ * @buf: The struct kstatfs to fill in with stats
+ *
+ * Get the filesystem statistics. As writes always target the upper layer
+ * filesystem pass the statfs to the same filesystem.
+ */
+static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct dentry *root_dentry = dentry->d_sb->s_root;
+ struct path path;
+ ovl_path_upper(root_dentry, &path);
+
+ if (!path.dentry->d_sb->s_op->statfs)
+ return -ENOSYS;
+ return path.dentry->d_sb->s_op->statfs(path.dentry, buf);
+}
+
static const struct super_operations ovl_super_operations = {
.put_super = ovl_put_super,
.remount_fs = ovl_remount_fs,
+ .statfs = ovl_statfs,
};
struct ovl_config {