quota: Allow each filesystem to specify which quota types it supports

Currently all filesystems supporting VFS quota support user and group
quotas. With introduction of project quotas this is going to change so
make sure filesystem isn't called for quota type it doesn't support by
introduction of a bitmask determining which quota types each filesystem
supports.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 11 insertions, 2 deletions

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 75621649dbd7..2aa4151f99d2 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -47,8 +47,11 @@ static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
 
 static void quota_sync_one(struct super_block *sb, void *arg)
 {
-        if (sb->s_qcop && sb->s_qcop->quota_sync)
-                sb->s_qcop->quota_sync(sb, *(int *)arg);
+        int type = *(int *)arg;
+
+        if (sb->s_qcop && sb->s_qcop->quota_sync &&
+            (sb->s_quota_types & (1 << type)))
+                sb->s_qcop->quota_sync(sb, type);
 }
 
 static int quota_sync_all(int type)
@@ -297,8 +300,14 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 
         if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
                 return -EINVAL;
+        /*
+         * Quota not supported on this fs? Check this before s_quota_types
+         * since they needn't be set if quota is not supported at all.
+         */
         if (!sb->s_qcop)
                 return -ENOSYS;
+        if (!(sb->s_quota_types & (1 << type)))
+                return -EINVAL;
 
         ret = check_quotactl_permission(sb, type, cmd, id);
         if (ret < 0)