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authorAndy Whitcroft <apw@canonical.com>2010-10-01 18:48:02 +0100
committerJohn Rigby <john.rigby@linaro.org>2012-06-25 15:02:26 -0600
commit9a0d2067840b61f1ba1bbb78374e2a19192c8130 (patch)
treef0c3c107f132ca20ff99bbce0560c49422af64ee
parent7108c97b9c91bd0244cf485137ab13ff8faf5b77 (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 {