aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndy Whitcroft <apw@canonical.com>2010-10-01 18:48:02 +0100
committerLinaro CI <john.rigby@linaro.org>2012-02-07 22:47:02 +0000
commitb0989cd2a3d9c70cb015ca51b515f8f1b039d84e (patch)
tree17b9d210e5496df00d5a0e412833bd0ea439d4ca
parent748f9fd84a1eec9dcef0ad8107f7465c4226c761 (diff)
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> Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
-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 64054e95a78..d8862e63026 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -396,9 +396,29 @@ 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 {