dquot: cleanup space allocation / freeing routines

Get rid of the alloc_space, free_space, reserve_space, claim_space and
release_rsv dquot operations - they are always called from the filesystem
and if a filesystem really needs their own (which none currently does)
it can just call into it's own routine directly.

Move shared logic into the common __dquot_alloc_space,
dquot_claim_space_nodirty and __dquot_free_space low-level methods,
and rationalize the wrappers around it to move as much as possible
code into the common block for CONFIG_QUOTA vs not.  Also rename
all these helpers to be named dquot_* instead of vfs_dq_*.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 28c3ec2..a63ea4d 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -2964,12 +2964,10 @@
 		goto out;
 	}
 
-	if (vfs_dq_alloc_space_nodirty(dir,
-				ocfs2_clusters_to_bytes(osb->sb,
-							alloc + dx_alloc))) {
-		ret = -EDQUOT;
+	ret = dquot_alloc_space_nodirty(dir,
+		ocfs2_clusters_to_bytes(osb->sb, alloc + dx_alloc));
+	if (ret)
 		goto out_commit;
-	}
 	did_quota = 1;
 
 	if (ocfs2_supports_indexed_dirs(osb) && !dx_inline) {
@@ -3178,7 +3176,7 @@
 
 out_commit:
 	if (ret < 0 && did_quota)
-		vfs_dq_free_space_nodirty(dir, bytes_allocated);
+		dquot_free_space_nodirty(dir, bytes_allocated);
 
 	ocfs2_commit_trans(osb, handle);
 
@@ -3221,11 +3219,10 @@
 	if (extend) {
 		u32 offset = OCFS2_I(dir)->ip_clusters;
 
-		if (vfs_dq_alloc_space_nodirty(dir,
-					ocfs2_clusters_to_bytes(sb, 1))) {
-			status = -EDQUOT;
+		status = dquot_alloc_space_nodirty(dir,
+					ocfs2_clusters_to_bytes(sb, 1));
+		if (status)
 			goto bail;
-		}
 		did_quota = 1;
 
 		status = ocfs2_add_inode_data(OCFS2_SB(sb), dir, &offset,
@@ -3254,7 +3251,7 @@
 	status = 0;
 bail:
 	if (did_quota && status < 0)
-		vfs_dq_free_space_nodirty(dir, ocfs2_clusters_to_bytes(sb, 1));
+		dquot_free_space_nodirty(dir, ocfs2_clusters_to_bytes(sb, 1));
 	mlog_exit(status);
 	return status;
 }
@@ -3889,11 +3886,10 @@
 		goto out;
 	}
 
-	if (vfs_dq_alloc_space_nodirty(dir,
-				       ocfs2_clusters_to_bytes(dir->i_sb, 1))) {
-		ret = -EDQUOT;
+	ret = dquot_alloc_space_nodirty(dir,
+				       ocfs2_clusters_to_bytes(dir->i_sb, 1));
+	if (ret)
 		goto out_commit;
-	}
 	did_quota = 1;
 
 	ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), dx_leaf_bh,
@@ -3983,7 +3979,7 @@
 
 out_commit:
 	if (ret < 0 && did_quota)
-		vfs_dq_free_space_nodirty(dir,
+		dquot_free_space_nodirty(dir,
 				ocfs2_clusters_to_bytes(dir->i_sb, 1));
 
 	ocfs2_commit_trans(osb, handle);
@@ -4165,11 +4161,10 @@
 		goto out;
 	}
 
-	if (vfs_dq_alloc_space_nodirty(dir,
-				       ocfs2_clusters_to_bytes(osb->sb, 1))) {
-		ret = -EDQUOT;
+	ret = dquot_alloc_space_nodirty(dir,
+				       ocfs2_clusters_to_bytes(osb->sb, 1));
+	if (ret)
 		goto out_commit;
-	}
 	did_quota = 1;
 
 	/*
@@ -4229,7 +4224,7 @@
 
 out_commit:
 	if (ret < 0 && did_quota)
-		vfs_dq_free_space_nodirty(dir,
+		dquot_free_space_nodirty(dir,
 					  ocfs2_clusters_to_bytes(dir->i_sb, 1));
 
 	ocfs2_commit_trans(osb, handle);