quota: Add ->quota_{enable,disable} callbacks for VFS quotas

Add functions which translate ->quota_enable / ->quota_disable calls
into appropriate changes in VFS quota. This will enable filesystems
supporting VFS quota files in system inodes to be controlled via
Q_XQUOTA[ON|OFF] quotactls for better userspace compatibility.

Also provide a vector for quotactl using these functions which can be
used by filesystems with quota files stored in hidden system files.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index ff0b665591d0..df73258cca47 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -166,6 +166,7 @@ static inline bool sb_has_quota_active(struct super_block *sb, int type)
  */
 extern const struct dquot_operations dquot_operations;
 extern const struct quotactl_ops dquot_quotactl_ops;
+extern const struct quotactl_ops dquot_quotactl_sysfile_ops;
 
 #else