This adds the ability to show root's generation when we use btrfs subvol list.
Signed-off-by: Liu Bo <liubo2...@cn.fujitsu.com>
---
btrfs-list.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 55 insertions(+), 6 deletions(-)
diff --git a/btrfs-list.c b/btrfs-list.c
index ac6507a..05360dc 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -57,6 +57,9 @@ struct root_info {
/* the dir id we're in from ref_tree */
u64 dir_id;
+ /* generation when the root is created or last updated */
+ u64 gen;
+
/* path from the subvol we live in to this root, including the
* root's name. This is null until we do the extra lookup ioctl.
*/
@@ -194,6 +197,19 @@ static int add_root(struct root_lookup *root_lookup,
return 0;
}
+static int update_root(struct root_lookup *root_lookup, u64 root_id, u64 gen)
+{
+ struct root_info *ri;
+
+ ri = tree_search(&root_lookup->root, root_id);
+ if (!ri || ri->root_id != root_id) {
+ fprintf(stderr, "could not find subvol %llu\n", root_id);
+ return -ENOENT;
+ }
+ ri->gen = gen;
+ return 0;
+}
+
/*
* for a given root_info, search through the root_lookup tree to construct
* the full path name to it.
@@ -615,11 +631,15 @@ static int __list_subvol_search(int fd, struct
root_lookup *root_lookup)
struct btrfs_ioctl_search_key *sk = &args.key;
struct btrfs_ioctl_search_header *sh;
struct btrfs_root_ref *ref;
+ struct btrfs_root_item *ri;
unsigned long off = 0;
int name_len;
char *name;
u64 dir_id;
+ u8 type;
+ u64 gen = 0;
int i;
+ int get_gen = 0;
root_lookup_init(root_lookup);
memset(&args, 0, sizeof(args));
@@ -644,6 +664,7 @@ static int __list_subvol_search(int fd, struct root_lookup
*root_lookup)
sk->max_offset = (u64)-1;
sk->max_transid = (u64)-1;
+again:
/* just a big number, doesn't matter much */
sk->nr_items = 4096;
@@ -665,7 +686,7 @@ static int __list_subvol_search(int fd, struct root_lookup
*root_lookup)
sh = (struct btrfs_ioctl_search_header *)(args.buf +
off);
off += sizeof(*sh);
- if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
+ if (!get_gen && sh->type == BTRFS_ROOT_BACKREF_KEY) {
ref = (struct btrfs_root_ref *)(args.buf + off);
name_len = btrfs_stack_root_ref_name_len(ref);
name = (char *)(ref + 1);
@@ -673,6 +694,11 @@ static int __list_subvol_search(int fd, struct root_lookup
*root_lookup)
add_root(root_lookup, sh->objectid, sh->offset,
dir_id, name, name_len);
+ } else if (get_gen && sh->type == BTRFS_ROOT_ITEM_KEY) {
+ ri = (struct btrfs_root_item *)(args.buf + off);
+ gen = btrfs_root_generation(ri);
+
+ update_root(root_lookup, sh->objectid, gen);
}
off += sh->len;
@@ -689,17 +715,38 @@ static int __list_subvol_search(int fd, struct
root_lookup *root_lookup)
/* this iteration is done, step forward one root for the next
* ioctl
*/
- if (sk->min_type < BTRFS_ROOT_BACKREF_KEY) {
- sk->min_type = BTRFS_ROOT_BACKREF_KEY;
+ if (get_gen)
+ type = BTRFS_ROOT_ITEM_KEY;
+ else
+ type = BTRFS_ROOT_BACKREF_KEY;
+
+ if (sk->min_type < type) {
+ sk->min_type = type;
sk->min_offset = 0;
} else if (sk->min_objectid < BTRFS_LAST_FREE_OBJECTID) {
sk->min_objectid++;
- sk->min_type = BTRFS_ROOT_BACKREF_KEY;
+ sk->min_type = type;
sk->min_offset = 0;
} else
break;
}
+ if (!get_gen) {
+ memset(&args, 0, sizeof(args));
+
+ sk->tree_id = 1;
+ sk->max_type = BTRFS_ROOT_ITEM_KEY;
+ sk->min_type = BTRFS_ROOT_ITEM_KEY;
+
+ sk->min_objectid = BTRFS_FIRST_FREE_OBJECTID;
+
+ sk->max_objectid = BTRFS_LAST_FREE_OBJECTID;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+
+ get_gen = 1;
+ goto again;
+ }
return 0;
}
@@ -781,13 +828,15 @@ int list_subvols(int fd, int print_parent, int
get_default)
resolve_root(&root_lookup, entry, &parent_id, &level, &path);
if (print_parent) {
- printf("ID %llu parent %llu top level %llu path %s\n",
+ printf("ID %llu gen %llu parent %llu top level %llu
path %s\n",
(unsigned long long)entry->root_id,
+ (unsigned long long)entry->gen,
(unsigned long long)parent_id,
(unsigned long long)level, path);
} else {
- printf("ID %llu top level %llu path %s\n",
+ printf("ID %llu gen %llu top level %llu path %s\n",
(unsigned long long)entry->root_id,
+ (unsigned long long)entry->gen,
(unsigned long long)level, path);
}
--
1.6.5.2
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