v4.19.13 snapshot.
diff --git a/include/linux/dqblk_qtree.h b/include/linux/dqblk_qtree.h
new file mode 100644
index 0000000..100d22a
--- /dev/null
+++ b/include/linux/dqblk_qtree.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Definitions of structures and functions for quota formats using trie
+ */
+
+#ifndef _LINUX_DQBLK_QTREE_H
+#define _LINUX_DQBLK_QTREE_H
+
+#include <linux/types.h>
+
+/* Numbers of blocks needed for updates - we count with the smallest
+ * possible block size (1024) */
+#define QTREE_INIT_ALLOC 4
+#define QTREE_INIT_REWRITE 2
+#define QTREE_DEL_ALLOC 0
+#define QTREE_DEL_REWRITE 6
+
+struct dquot;
+struct kqid;
+
+/* Operations */
+struct qtree_fmt_operations {
+ void (*mem2disk_dqblk)(void *disk, struct dquot *dquot); /* Convert given entry from in memory format to disk one */
+ void (*disk2mem_dqblk)(struct dquot *dquot, void *disk); /* Convert given entry from disk format to in memory one */
+ int (*is_id)(void *disk, struct dquot *dquot); /* Is this structure for given id? */
+};
+
+/* Inmemory copy of version specific information */
+struct qtree_mem_dqinfo {
+ struct super_block *dqi_sb; /* Sb quota is on */
+ int dqi_type; /* Quota type */
+ unsigned int dqi_blocks; /* # of blocks in quota file */
+ unsigned int dqi_free_blk; /* First block in list of free blocks */
+ unsigned int dqi_free_entry; /* First block with free entry */
+ unsigned int dqi_blocksize_bits; /* Block size of quota file */
+ unsigned int dqi_entry_size; /* Size of quota entry in quota file */
+ unsigned int dqi_usable_bs; /* Space usable in block for quota data */
+ unsigned int dqi_qtree_depth; /* Precomputed depth of quota tree */
+ const struct qtree_fmt_operations *dqi_ops; /* Operations for entry manipulation */
+};
+
+int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
+int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
+int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
+int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot);
+int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk);
+static inline int qtree_depth(struct qtree_mem_dqinfo *info)
+{
+ unsigned int epb = info->dqi_usable_bs >> 2;
+ unsigned long long entries = epb;
+ int i;
+
+ for (i = 1; entries < (1ULL << 32); i++)
+ entries *= epb;
+ return i;
+}
+int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid);
+
+#endif /* _LINUX_DQBLK_QTREE_H */