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authorAndy Whitcroft <apw@canonical.com>2010-10-01 18:48:02 +0100
committerLeann Ogasawara <leann.ogasawara@canonical.com>2012-06-19 00:02:45 -0700
commit93773ccec06903b6ef7348c6946e7bb384cb23aa (patch)
tree741d1cce5aa735378e1f80144caf6867213ffa50
parentccebb9a7951f32fb0cfe012a7c8d56ee512ec241 (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 0aaa4c29546..50cbef5e400 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 {