[PATCH v2 1/9] Btrfs-progs: restructure show_qgroups

[Wang Shilong <wangsl.fnst@cn.fujitsu.com>]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

The current show_qgroups() just shows a little information, and it is hard to
add some functions which the users need in the future, so i restructure it, make
it easy to add new functions.

In order to improve the scalability of show_qgroups(), i add some important
structures:

	struct qgroup_lookup {
		struct rb_root root;
	}
 	/*
	*store qgroup's information
	*/
	struct btrfs_qgroup {
		struct rb_node  rb_node;
		u64 qgroupid;

		u64 generation;
		u64 rfer;
		u64 rfer_cmpr;
		u64 excl_cmpr;

		u64 flags;
		u64 max_rfer;
		u64 max_excl;
		u64 rsv_rfer;
		u64 rsv_excl;

		struct list_head qgroups;
		struct list_head members;
	}
	/*
	*glue structure to represent the relations
	*between qgroups
	*/
	struct btrfs_qgroup_list {
		struct list_head next_qgroups;
		struct list_head next_member;
		struct btrfs_qgroup *qgroup;
		struct btrfs_qgroup *member;
	}
The above 3 structures are used to manage all the information
of qgroups.

	struct {
		char *name;
		char *column_name;
		int need_print;
	} btrfs_qgroup_columns[]

We define a arrary to manage all the columns that can be
outputed, and use a member variant(->need_print) to control
the output of the relative column. Some columns are outputed
by default. But we can change it according to the requirement
of the users.

For example:
	if outputing max referenced size of qgroup is needed,the function
'btrfs_qgroup_setup_column()' will be called, and the parameter 'BTRFS_QGROUP_MAX_RFER'
(extend in the future) will be passsed to the function. After the function is done,
when showing qgroups, max referenced size of qgroup will be output.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 cmds-qgroup.c |  91 +----------
 ctree.h       |  11 ++
 qgroup.c      | 509 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qgroup.h      |  10 ++
 4 files changed, 531 insertions(+), 90 deletions(-)

diff --git a/cmds-qgroup.c b/cmds-qgroup.c
index ff2a1fa..d3c699f 100644
--- a/cmds-qgroup.c
+++ b/cmds-qgroup.c
@@ -106,95 +106,6 @@ static int qgroup_create(int create, int argc, char **argv)
 	return 0;
 }
 
-static void print_qgroup_info(u64 objectid, struct btrfs_qgroup_info_item *info)
-{
-	printf("%llu/%llu %lld %lld\n", objectid >> 48,
-		objectid & ((1ll << 48) - 1),
-		btrfs_stack_qgroup_info_referenced(info),
-		btrfs_stack_qgroup_info_exclusive(info));
-}
-
-static int list_qgroups(int fd)
-{
-	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
-	struct btrfs_ioctl_search_header *sh;
-	unsigned long off = 0;
-	unsigned int i;
-	struct btrfs_qgroup_info_item *info;
-
-	memset(&args, 0, sizeof(args));
-
-	/* search in the quota tree */
-	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
-
-	/*
-	 * set the min and max to backref keys.  The search will
-	 * only send back this type of key now.
-	 */
-	sk->max_type = BTRFS_QGROUP_INFO_KEY;
-	sk->min_type = BTRFS_QGROUP_INFO_KEY;
-	sk->max_objectid = 0;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-
-	/* just a big number, doesn't matter much */
-	sk->nr_items = 4096;
-
-	while (1) {
-		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
-		if (ret < 0)
-			return ret;
-
-		/* the ioctl returns the number of item it found in nr_items */
-		if (sk->nr_items == 0)
-			break;
-
-		off = 0;
-
-		/*
-		 * for each item, pull the key out of the header and then
-		 * read the root_ref item it contains
-		 */
-		for (i = 0; i < sk->nr_items; i++) {
-			sh = (struct btrfs_ioctl_search_header *)(args.buf +
-								  off);
-			off += sizeof(*sh);
-
-			if (sh->objectid != 0)
-				goto done;
-
-			if (sh->type != BTRFS_QGROUP_INFO_KEY)
-				goto done;
-
-			info = (struct btrfs_qgroup_info_item *)
-					(args.buf + off);
-			print_qgroup_info(sh->offset, info);
-
-			off += sh->len;
-
-			/*
-			 * record the mins in sk so we can make sure the
-			 * next search doesn't repeat this root
-			 */
-			sk->min_offset = sh->offset;
-		}
-		sk->nr_items = 4096;
-		/*
-		 * this iteration is done, step forward one qgroup for the next
-		 * ioctl
-		 */
-		if (sk->min_offset < (u64)-1)
-			sk->min_offset++;
-		else
-			break;
-	}
-
-done:
-	return ret;
-}
-
 static int parse_limit(const char *p, unsigned long long *s)
 {
 	char *endptr;
@@ -313,7 +224,7 @@ static int cmd_qgroup_show(int argc, char **argv)
 		return 1;
 	}
 
-	ret = list_qgroups(fd);
+	ret = btrfs_show_qgroups(fd);
 	e = errno;
 	close_file_or_dir(fd, dirstream);
 	if (ret < 0)
diff --git a/ctree.h b/ctree.h
index 5b4c859..c90581a 100644
--- a/ctree.h
+++ b/ctree.h
@@ -2059,6 +2059,17 @@ BTRFS_SETGET_FUNCS(qgroup_limit_rsv_referenced, struct btrfs_qgroup_limit_item,
 BTRFS_SETGET_FUNCS(qgroup_limit_rsv_exclusive, struct btrfs_qgroup_limit_item,
 		   rsv_exclusive, 64);
 
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_flags,
+			 struct btrfs_qgroup_limit_item, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_max_referenced,
+			 struct btrfs_qgroup_limit_item, max_referenced, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_max_exclusive,
+			 struct btrfs_qgroup_limit_item, max_exclusive, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_rsv_referenced,
+			 struct btrfs_qgroup_limit_item, rsv_referenced, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_rsv_exclusive,
+			 struct btrfs_qgroup_limit_item, rsv_exclusive, 64);
+
 /* this returns the number of file bytes represented by the inline item.
  * If an item is compressed, this is the uncompressed size
  */
diff --git a/qgroup.c b/qgroup.c
index 86fe2b2..bd9658e 100644
--- a/qgroup.c
+++ b/qgroup.c
@@ -17,7 +17,516 @@
  */
 
 #include "qgroup.h"
+#include <sys/ioctl.h>
 #include "ctree.h"
+#include "ioctl.h"
+
+struct qgroup_lookup {
+	struct rb_root root;
+};
+
+struct btrfs_qgroup {
+	struct rb_node rb_node;
+	u64 qgroupid;
+
+	/*
+	 * info_item
+	 */
+	u64 generation;
+	u64 rfer;	/*referenced*/
+	u64 rfer_cmpr;	/*referenced compressed*/
+	u64 excl;	/*exclusive*/
+	u64 excl_cmpr;	/*exclusive compressed*/
+
+	/*
+	 *limit_item
+	 */
+	u64 flags;	/*which limits are set*/
+	u64 max_rfer;
+	u64 max_excl;
+	u64 rsv_rfer;
+	u64 rsv_excl;
+
+	/*qgroups this group is member of*/
+	struct list_head qgroups;
+	/*qgroups that are members of this group*/
+	struct list_head members;
+};
+
+/*
+ * glue structure to represent the relations
+ * between qgroups
+ */
+struct btrfs_qgroup_list {
+	struct list_head next_qgroup;
+	struct list_head next_member;
+	struct btrfs_qgroup *qgroup;
+	struct btrfs_qgroup *member;
+};
+
+/*
+ * qgroupid,rfer,excl default to set
+ */
+struct {
+	char *name;
+	char *column_name;
+	int need_print;
+} btrfs_qgroup_columns[] = {
+	{
+		.name		= "qgroupid",
+		.column_name	= "Qgroupid",
+		.need_print	= 1,
+	},
+	{
+		.name		= "rfer",
+		.column_name	= "Rfer",
+		.need_print	= 1,
+	},
+	{
+		.name		= "excl",
+		.column_name	= "Excl",
+		.need_print	= 1,
+	},
+	{
+		.name		= NULL,
+		.column_name	= NULL,
+		.need_print	= 0,
+	},
+};
+
+void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column)
+{
+	int i;
+
+	BUG_ON(column < 0 || column > BTRFS_QGROUP_ALL);
+
+	if (column < BTRFS_QGROUP_ALL) {
+		btrfs_qgroup_columns[column].need_print = 1;
+		return;
+	}
+	for (i = 0; i < BTRFS_QGROUP_ALL; i++)
+		btrfs_qgroup_columns[i].need_print = 1;
+}
+
+static void print_qgroup_column(struct btrfs_qgroup *qgroup,
+				enum btrfs_qgroup_column_enum column)
+{
+	BUG_ON(column >= BTRFS_QGROUP_ALL || column < 0);
+
+	switch (column) {
+
+	case BTRFS_QGROUP_QGROUPID:
+		printf("%llu/%llu", qgroup->qgroupid >> 48,
+		       ((1ll << 48) - 1) & qgroup->qgroupid);
+		break;
+	case BTRFS_QGROUP_RFER:
+		printf("%lld", qgroup->rfer);
+		break;
+	case BTRFS_QGROUP_EXCL:
+		printf("%lld", qgroup->excl);
+		break;
+	default:
+		break;
+	}
+}
+
+static void print_single_qgroup_default(struct btrfs_qgroup *qgroup)
+{
+	int i;
+
+	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
+		if (!btrfs_qgroup_columns[i].need_print)
+			continue;
+		print_qgroup_column(qgroup, i);
+
+		if (i != BTRFS_QGROUP_ALL - 1)
+			printf(" ");
+	}
+	printf("\n");
+}
+
+static void qgroup_lookup_init(struct qgroup_lookup *tree)
+{
+	tree->root.rb_node = NULL;
+}
+
+static int comp_entry_with_qgroupid(struct btrfs_qgroup *entry1,
+				    struct btrfs_qgroup *entry2,
+				    int is_descending)
+{
+
+	int ret;
+
+	if (entry1->qgroupid > entry2->qgroupid)
+		ret = 1;
+	else if (entry1->qgroupid < entry2->qgroupid)
+		ret = -1;
+	else
+		ret = 0;
+
+	return is_descending ? -ret : ret;
+}
+
+/*
+ * insert a new root into the tree.  returns the existing root entry
+ * if one is already there.  qgroupid is used
+ * as the key
+ */
+static int qgroup_tree_insert(struct qgroup_lookup *root_tree,
+			      struct btrfs_qgroup *ins)
+{
+
+	struct rb_node **p = &root_tree->root.rb_node;
+	struct rb_node *parent = NULL;
+	struct btrfs_qgroup *curr;
+	int ret;
+
+	while (*p) {
+		parent = *p;
+		curr = rb_entry(parent, struct btrfs_qgroup, rb_node);
+
+		ret = comp_entry_with_qgroupid(ins, curr, 0);
+		if (ret < 0)
+			p = &(*p)->rb_left;
+		else if (ret > 0)
+			p = &(*p)->rb_right;
+		else
+			return -EEXIST;
+	}
+	rb_link_node(&ins->rb_node, parent, p);
+	rb_insert_color(&ins->rb_node, &root_tree->root);
+	return 0;
+}
+
+/*
+ *find a given qgroupid in the tree. We return the smallest one,
+ *rb_next can be used to move forward looking for more if required
+ */
+static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
+					       u64 qgroupid)
+{
+	struct rb_node *n = root_tree->root.rb_node;
+	struct btrfs_qgroup *entry;
+	struct btrfs_qgroup tmp;
+	int ret;
+
+	tmp.qgroupid = qgroupid;
+
+	while (n) {
+		entry = rb_entry(n, struct btrfs_qgroup, rb_node);
+
+		ret = comp_entry_with_qgroupid(&tmp, entry, 0);
+		if (ret < 0)
+			n = n->rb_left;
+		else if (ret > 0)
+			n = n->rb_right;
+		else
+			return entry;
+
+	}
+	return NULL;
+}
+
+static int update_qgroup(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
+			 u64 generation, u64 rfer, u64 rfer_cmpr, u64 excl,
+			 u64 excl_cmpr, u64 flags, u64 max_rfer, u64 max_excl,
+			 u64 rsv_rfer, u64 rsv_excl, struct btrfs_qgroup *pa,
+			 struct btrfs_qgroup *child)
+{
+	struct btrfs_qgroup *bq;
+	struct btrfs_qgroup_list *list;
+
+	bq = qgroup_tree_search(qgroup_lookup, qgroupid);
+	if (!bq || bq->qgroupid != qgroupid)
+		return -ENOENT;
+
+	if (generation)
+		bq->generation = generation;
+	if (rfer)
+		bq->rfer = rfer;
+	if (rfer_cmpr)
+		bq->rfer_cmpr = rfer_cmpr;
+	if (excl)
+		bq->excl = excl;
+	if (excl_cmpr)
+		bq->excl_cmpr = excl_cmpr;
+	if (flags)
+		bq->flags = flags;
+	if (max_rfer)
+		bq->max_rfer = max_rfer;
+	if (max_excl)
+		bq->max_excl = max_excl;
+	if (rsv_rfer)
+		bq->rsv_rfer = rsv_rfer;
+	if (pa && child) {
+		list = malloc(sizeof(*list));
+		if (!list) {
+			fprintf(stderr, "memory allocation failed\n");
+			exit(1);
+		}
+		list->qgroup = pa;
+		list->member = child;
+		list_add_tail(&list->next_qgroup, &child->qgroups);
+		list_add_tail(&list->next_member, &pa->members);
+	}
+	return 0;
+}
+
+static int add_qgroup(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
+		      u64 generation, u64 rfer, u64 rfer_cmpr, u64 excl,
+		      u64 excl_cmpr, u64 flags, u64 max_rfer, u64 max_excl,
+		      u64 rsv_rfer, u64 rsv_excl, struct btrfs_qgroup *parent,
+		      struct btrfs_qgroup *child)
+{
+	struct btrfs_qgroup *bq;
+	struct btrfs_qgroup_list *list;
+	int ret;
+
+	ret = update_qgroup(qgroup_lookup, qgroupid, generation, rfer,
+			    rfer_cmpr, excl, excl_cmpr, flags, max_rfer,
+			    max_excl, rsv_rfer, rsv_excl, parent, child);
+	if (!ret)
+		return 0;
+
+	bq = malloc(sizeof(*bq));
+	if (!bq) {
+		printf("memory allocation failed\n");
+		exit(1);
+	}
+	memset(bq, 0, sizeof(*bq));
+	if (qgroupid) {
+		bq->qgroupid = qgroupid;
+		INIT_LIST_HEAD(&bq->qgroups);
+		INIT_LIST_HEAD(&bq->members);
+	}
+	if (generation)
+		bq->generation = generation;
+	if (rfer)
+		bq->rfer = rfer;
+	if (rfer_cmpr)
+		bq->rfer_cmpr = rfer_cmpr;
+	if (excl)
+		bq->excl = excl;
+	if (excl_cmpr)
+		bq->excl_cmpr = excl_cmpr;
+	if (flags)
+		bq->flags = flags;
+	if (max_rfer)
+		bq->max_rfer = max_rfer;
+	if (max_excl)
+		bq->max_excl = max_excl;
+	if (rsv_rfer)
+		bq->rsv_rfer = rsv_rfer;
+	if (parent && child) {
+		list = malloc(sizeof(*list));
+		if (!list) {
+			fprintf(stderr, "memory allocation failed\n");
+			exit(1);
+		}
+		list->qgroup = parent;
+		list->member = child;
+		list_add_tail(&list->next_qgroup, &child->qgroups);
+		list_add_tail(&list->next_member, &parent->members);
+	}
+	ret = qgroup_tree_insert(qgroup_lookup, bq);
+	if (ret) {
+		printf("failed to insert tree %llu\n",
+		       bq->qgroupid);
+		exit(1);
+	}
+	return ret;
+}
+
+void __free_btrfs_qgroup(struct btrfs_qgroup *bq)
+{
+	struct btrfs_qgroup_list *list;
+	while (!list_empty(&bq->qgroups)) {
+		list = list_entry((&bq->qgroups)->next,
+				  struct btrfs_qgroup_list,
+				  next_qgroup);
+		list_del(&list->next_qgroup);
+		list_del(&list->next_member);
+		free(list);
+	}
+	while (!list_empty(&bq->members)) {
+		list = list_entry((&bq->members)->next,
+				  struct btrfs_qgroup_list,
+				  next_member);
+		list_del(&list->next_qgroup);
+		list_del(&list->next_member);
+		free(list);
+	}
+	free(bq);
+}
+
+void __free_all_qgroups(struct qgroup_lookup *root_tree)
+{
+	struct btrfs_qgroup *entry;
+	struct rb_node *n;
+
+	n = rb_first(&root_tree->root);
+	while (n) {
+		entry = rb_entry(n, struct btrfs_qgroup, rb_node);
+		rb_erase(n, &root_tree->root);
+		__free_btrfs_qgroup(entry);
+
+		n = rb_first(&root_tree->root);
+	}
+}
+
+static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
+{
+	int ret;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	unsigned long off = 0;
+	unsigned int i;
+	int e;
+	struct btrfs_qgroup_info_item *info;
+	struct btrfs_qgroup_limit_item *limit;
+	struct btrfs_qgroup *bq;
+	struct btrfs_qgroup *bq1;
+	u64 a1;
+	u64 a2;
+	u64 a3;
+	u64 a4;
+	u64 a5;
+
+	memset(&args, 0, sizeof(args));
+
+	sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
+	sk->max_type = BTRFS_QGROUP_RELATION_KEY;
+	sk->min_type = BTRFS_QGROUP_INFO_KEY;
+	sk->max_objectid = (u64)-1;
+	sk->max_offset = (u64)-1;
+	sk->max_transid = (u64)-1;
+	sk->nr_items = 4096;
+
+	qgroup_lookup_init(qgroup_lookup);
+
+	while (1) {
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		e = errno;
+		if (ret < 0) {
+			fprintf(stderr,
+				"ERROR: can't perform the search - %s\n",
+				strerror(e));
+			return ret;
+		}
+		/* the ioctl returns the number of item it found in nr_items */
+		if (sk->nr_items == 0)
+			break;
+
+		off = 0;
+		/*
+		 * for each item, pull the key out of the header and then
+		 * read the root_ref item it contains
+		 */
+		for (i = 0; i < sk->nr_items; i++) {
+			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+								  off);
+			off += sizeof(*sh);
+
+			if (sh->type == BTRFS_QGROUP_INFO_KEY) {
+				info = (struct btrfs_qgroup_info_item *)
+				       (args.buf + off);
+				a1 = btrfs_stack_qgroup_info_generation(info);
+				a2 = btrfs_stack_qgroup_info_referenced(info);
+				a3 =
+				  btrfs_stack_qgroup_info_referenced_compressed
+				  (info);
+				a4 = btrfs_stack_qgroup_info_exclusive(info);
+				a5 =
+				  btrfs_stack_qgroup_info_exclusive_compressed
+				  (info);
+				add_qgroup(qgroup_lookup, sh->offset, a1, a2,
+					   a3, a4, a5, 0, 0, 0, 0, 0, 0, 0);
+			} else if (sh->type == BTRFS_QGROUP_LIMIT_KEY) {
+				limit = (struct btrfs_qgroup_limit_item *)
+				    (args.buf + off);
+
+				a1 = btrfs_stack_qgroup_limit_flags(limit);
+				a2 = btrfs_stack_qgroup_limit_max_referenced
+				     (limit);
+				a3 = btrfs_stack_qgroup_limit_max_exclusive
+				     (limit);
+				a4 = btrfs_stack_qgroup_limit_rsv_referenced
+				     (limit);
+				a5 = btrfs_stack_qgroup_limit_rsv_exclusive
+				     (limit);
+				add_qgroup(qgroup_lookup, sh->offset, 0, 0,
+					   0, 0, 0, a1, a2, a3, a4, a5, 0, 0);
+			} else if (sh->type == BTRFS_QGROUP_RELATION_KEY) {
+				if (sh->offset < sh->objectid)
+					goto skip;
+				bq = qgroup_tree_search(qgroup_lookup,
+							sh->offset);
+				if (!bq)
+					goto skip;
+				bq1 = qgroup_tree_search(qgroup_lookup,
+							 sh->objectid);
+				if (!bq1)
+					goto skip;
+				add_qgroup(qgroup_lookup, sh->offset, 0, 0,
+					   0, 0, 0, 0, 0, 0, 0, 0, bq, bq1);
+			} else
+				goto done;
+skip:
+			off += sh->len;
+
+			/*
+			 * record the mins in sk so we can make sure the
+			 * next search doesn't repeat this root
+			 */
+			sk->min_type = sh->type;
+			sk->min_offset = sh->offset;
+			sk->min_objectid = sh->objectid;
+		}
+		sk->nr_items = 4096;
+		/*
+		 * this iteration is done, step forward one qgroup for the next
+		 * ioctl
+		 */
+		if (sk->min_offset < (u64)-1)
+			sk->min_offset++;
+		else
+			break;
+	}
+
+done:
+	return ret;
+}
+
+static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup)
+{
+
+	struct rb_node *n;
+	struct btrfs_qgroup *entry;
+
+	n = rb_first(&qgroup_lookup->root);
+	while (n) {
+		entry = rb_entry(n, struct btrfs_qgroup, rb_node);
+		print_single_qgroup_default(entry);
+		n = rb_next(n);
+	}
+}
+
+int btrfs_show_qgroups(int fd)
+{
+
+	struct qgroup_lookup qgroup_lookup;
+	int ret;
+
+	ret = __qgroups_search(fd, &qgroup_lookup);
+	if (ret)
+		return ret;
+
+	print_all_qgroups(&qgroup_lookup);
+	__free_all_qgroups(&qgroup_lookup);
+
+	return ret;
+}
 
 u64 parse_qgroupid(char *p)
 {
diff --git a/qgroup.h b/qgroup.h
index da6d113..8b34cd7 100644
--- a/qgroup.h
+++ b/qgroup.h
@@ -22,6 +22,16 @@
 #include "ioctl.h"
 #include "kerncompat.h"
 
+enum btrfs_qgroup_column_enum {
+	BTRFS_QGROUP_QGROUPID,
+	BTRFS_QGROUP_RFER,
+	BTRFS_QGROUP_EXCL,
+	BTRFS_QGROUP_ALL,
+};
+
+int  btrfs_show_qgroups(int fd);
+void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column);
+
 u64 parse_qgroupid(char *p);
 int qgroup_inherit_size(struct btrfs_qgroup_inherit *p);
 int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg);
-- 
1.8.3.1