vfs: Add general support to enforce project quota limits

This patch adds support for a new quota type PRJQUOTA for project quota
enforcement. Also a new method get_projid() is added into dquot_operations
structure.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 17 insertions, 3 deletions

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 327a58448592..ecc25cf0ee6e 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1163,8 +1163,8 @@ static int need_print_warning(struct dquot_warn *warn)
                         return uid_eq(current_fsuid(), warn->w_dq_id.uid);
                 case GRPQUOTA:
                         return in_group_p(warn->w_dq_id.gid);
-                case PRJQUOTA:  /* Never taken... Just make gcc happy */
-                        return 0;
+                case PRJQUOTA:
+                        return 1;
         }
         return 0;
 }
@@ -1405,6 +1405,9 @@ static void __dquot_initialize(struct inode *inode, int type)
         /* First get references to structures we might need. */
         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
                 struct kqid qid;
+                kprojid_t projid;
+                int rc;
+
                 got[cnt] = NULL;
                 if (type != -1 && cnt != type)
                         continue;
@@ -1415,6 +1418,10 @@ static void __dquot_initialize(struct inode *inode, int type)
                  */
                 if (dquots[cnt])
                         continue;
+
+                if (!sb_has_quota_active(sb, cnt))
+                        continue;
+
                 init_needed = 1;
 
                 switch (cnt) {
@@ -1424,6 +1431,12 @@ static void __dquot_initialize(struct inode *inode, int type)
                 case GRPQUOTA:
                         qid = make_kqid_gid(inode->i_gid);
                         break;
+                case PRJQUOTA:
+                        rc = inode->i_sb->dq_op->get_projid(inode, &projid);
+                        if (rc)
+                                continue;
+                        qid = make_kqid_projid(projid);
+                        break;
                 }
                 got[cnt] = dqget(sb, qid);
         }
@@ -2176,7 +2189,8 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
                 error = -EROFS;
                 goto out_fmt;
         }
-        if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
+        if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
+            (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
                 error = -EINVAL;
                 goto out_fmt;
         }