Show the absolute subvol path for the associated level-0 qgroup.
Signed-off-by: Lu Fengqi <lufq.fnst@xxxxxxxxxxxxxx>
---
Changelog:
v2:
rebase on the qgroup cleanup
qgroup.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
qgroup.h | 1 +
2 files changed, 106 insertions(+), 6 deletions(-)
diff --git a/qgroup.c b/qgroup.c
index b5b893f4..cfaed5ba 100644
--- a/qgroup.c
+++ b/qgroup.c
@@ -62,6 +62,9 @@ struct btrfs_qgroup {
struct list_head qgroups;
/*qgroups that are members of this group*/
struct list_head members;
+
+ /* level-0 qgroup's subvolume path */
+ char *path;
};
/*
@@ -133,6 +136,13 @@ static struct {
.unit_mode = 0,
.max_len = 5,
},
+ {
+ .name = "path",
+ .column_name = "Path",
+ .need_print = 1,
+ .unit_mode = 0,
+ .max_len = 4,
+ },
{
.name = NULL,
.column_name = NULL,
@@ -253,6 +263,9 @@ static void print_qgroup_column(struct btrfs_qgroup *qgroup,
len = print_child_column(qgroup);
print_qgroup_column_add_blank(BTRFS_QGROUP_CHILD, len);
break;
+ case BTRFS_QGROUP_PATH:
+ len = printf("%s", qgroup->path ? qgroup->path : "---");
+ print_qgroup_column_add_blank(BTRFS_QGROUP_PATH, len);
default:
break;
}
@@ -267,7 +280,7 @@ static void print_single_qgroup_table(struct btrfs_qgroup *qgroup)
continue;
print_qgroup_column(qgroup, i);
- if (i != BTRFS_QGROUP_CHILD)
+ if (i != BTRFS_QGROUP_ALL - 1)
printf(" ");
}
printf("\n");
@@ -284,7 +297,7 @@ static void print_table_head(void)
if (!btrfs_qgroup_columns[i].need_print)
continue;
if ((i == BTRFS_QGROUP_QGROUPID) | (i == BTRFS_QGROUP_PARENT) |
- (i == BTRFS_QGROUP_CHILD))
+ (i == BTRFS_QGROUP_CHILD) | (i == BTRFS_QGROUP_PATH))
printf("%-*s", max_len, btrfs_qgroup_columns[i].name);
else
printf("%*s", max_len, btrfs_qgroup_columns[i].name);
@@ -296,7 +309,7 @@ static void print_table_head(void)
if (!btrfs_qgroup_columns[i].need_print)
continue;
if ((i == BTRFS_QGROUP_QGROUPID) | (i == BTRFS_QGROUP_PARENT) |
- (i == BTRFS_QGROUP_CHILD)) {
+ (i == BTRFS_QGROUP_CHILD) | (i == BTRFS_QGROUP_PATH)) {
len = strlen(btrfs_qgroup_columns[i].name);
while (len--)
printf("-");
@@ -619,8 +632,86 @@ static struct btrfs_qgroup *get_or_add_qgroup(
return bq;
}
-static int update_qgroup_info(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
- struct btrfs_qgroup_info_item *info)
+/*
+ * Construct subvolume path for level-0 qgroup according to qgroupid.
+ *
+ * Return a potiner to the path string on success.
+ * Return NULL on error or qgroup level > 0.
+ */
+static char *qgroups_path_lookup(int fd, struct qgroup_lookup *qgroup_lookup,
+ u64 qgroupid)
+{
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+ struct btrfs_root_ref *ref;
+ struct btrfs_ioctl_search_header sh;
+ struct btrfs_qgroup *bq;
+ char *name, *path;
+ u64 subvol_id;
+ int name_len;
+ int ret;
+
+ /* only level-0 qgroup has the corresponding subvolume*/
+ if (btrfs_qgroup_level(qgroupid))
+ return NULL;
+
+ subvol_id = btrfs_qgroup_subvid(qgroupid);
+ if (subvol_id < BTRFS_FIRST_FREE_OBJECTID ||
+ subvol_id > BTRFS_LAST_FREE_OBJECTID)
+ return NULL;
+
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+ sk->max_type = BTRFS_ROOT_BACKREF_KEY;
+ sk->min_type = BTRFS_ROOT_BACKREF_KEY;
+ sk->max_objectid = subvol_id;
+ sk->min_objectid = subvol_id;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+
+ sk->nr_items = 4096;
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+ if (ret < 0)
+ return NULL;
+ if (!sk->nr_items)
+ return NULL;
+
+ /* resolve the ROOT_BACKREF to get the subvolume name*/
+ memcpy(&sh, args.buf, sizeof(sh));
+ ref = (struct btrfs_root_ref *)(args.buf + sizeof(sh));
+ name_len = btrfs_stack_root_ref_name_len(ref);
+ name = (char *)(ref + 1);
+
+ /*
+ * directly return subvolume name if top level is the initial subvolume
+ */
+ if (sh.offset == BTRFS_FS_TREE_OBJECTID)
+ return strndup(name, name_len);
+
+ /*
+ * construct path based on the upper subvolume path and the subvolume
+ * name
+ */
+ bq = qgroup_tree_search(qgroup_lookup, sh.offset);
+ if (!bq || bq->qgroupid != sh.offset)
+ return NULL;
+
+ /*
+ * 2 means the path delimiter '/' and the terminating null byte ('\0')
+ */
+ path = malloc(strlen(name) + strlen(bq->path) + 2);
+ if (!path) {
+ perror("malloc failed");
+ exit(1);
+ }
+ sprintf(path, "%s/%s", bq->path, name);
+
+ return path;
+}
+
+static int update_qgroup_info(int fd, struct qgroup_lookup *qgroup_lookup,
+ u64 qgroupid, struct btrfs_qgroup_info_item *info)
{
struct btrfs_qgroup *bq;
@@ -633,6 +724,7 @@ static int update_qgroup_info(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
bq->rfer_cmpr = btrfs_stack_qgroup_info_referenced_compressed(info);
bq->excl = btrfs_stack_qgroup_info_exclusive(info);
bq->excl_cmpr = btrfs_stack_qgroup_info_exclusive_compressed(info);
+ bq->path = qgroups_path_lookup(fd, qgroup_lookup, qgroupid);
return 0;
}
@@ -712,6 +804,8 @@ static void __free_btrfs_qgroup(struct btrfs_qgroup *bq)
list_del(&list->next_member);
free(list);
}
+ if (bq->path)
+ free(bq->path);
free(bq);
}
@@ -985,6 +1079,11 @@ static void __update_columns_max_len(struct btrfs_qgroup *bq,
if (btrfs_qgroup_columns[column].max_len < len)
btrfs_qgroup_columns[column].max_len = len;
break;
+ case BTRFS_QGROUP_PATH:
+ len = bq->path ? strlen(bq->path) : 0;
+ if (btrfs_qgroup_columns[column].max_len < len)
+ btrfs_qgroup_columns[column].max_len = len;
+ break;
default:
break;
}
@@ -1107,7 +1206,7 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
info = (struct btrfs_qgroup_info_item *)
(args.buf + off);
- ret = update_qgroup_info(qgroup_lookup,
+ ret = update_qgroup_info(fd, qgroup_lookup,
qgroupid, info);
break;
case BTRFS_QGROUP_LIMIT_KEY:
diff --git a/qgroup.h b/qgroup.h
index 875fbdf3..2003f834 100644
--- a/qgroup.h
+++ b/qgroup.h
@@ -59,6 +59,7 @@ enum btrfs_qgroup_column_enum {
BTRFS_QGROUP_MAX_EXCL,
BTRFS_QGROUP_PARENT,
BTRFS_QGROUP_CHILD,
+ BTRFS_QGROUP_PATH,
BTRFS_QGROUP_ALL,
};
--
2.14.3
--
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