Hi,
When listing subvolumes it can be useful to filter out any snapshots;
surprisingly enough I couldn't find an option to do this easily, only
the opposite (list only snapshots).
A "root" subvolume is identified by a null parent UUID, so adding a new
subvolume filter and flag -P ("Parent") does the trick.
The same can of course be accomplished with shell hackery, e.g.:
btrfs subvol list -q -o <path> | grep -i "parent_uuid -" | cut -d " " -f 11
but a built-in way seems less fragile.
I originally cooked this up for myself, but David Sterba encouraged me to
send this to the list, so here it is. I'm not too proud of the -P but
couldn't find a better option letter; suggestions welcome. :)
cheers,
Holger
Signed-off-by: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx>
---
btrfs-list.c | 6 ++++++
btrfs-list.h | 1 +
cmds-subvolume.c | 8 +++++++-
3 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/btrfs-list.c b/btrfs-list.c
index 4cc2ed49..6aa7a290 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1175,6 +1175,11 @@ static int filter_deleted(struct root_info *ri, u64 data)
return ri->deleted;
}
+static int filter_parent_subvol_only(struct root_info *ri, u64 data)
+{
+ return uuid_is_null(ri->puuid);
+}
+
static btrfs_list_filter_func all_filter_funcs[] = {
[BTRFS_LIST_FILTER_ROOTID] = filter_by_rootid,
[BTRFS_LIST_FILTER_SNAPSHOT_ONLY] = filter_snapshot,
@@ -1189,6 +1194,7 @@ static btrfs_list_filter_func all_filter_funcs[] = {
[BTRFS_LIST_FILTER_FULL_PATH] = filter_full_path,
[BTRFS_LIST_FILTER_BY_PARENT] = filter_by_parent,
[BTRFS_LIST_FILTER_DELETED] = filter_deleted,
+ [BTRFS_LIST_FILTER_PARENT_SUBVOL_ONLY] = filter_parent_subvol_only,
};
struct btrfs_list_filter_set *btrfs_list_alloc_filter_set(void)
diff --git a/btrfs-list.h b/btrfs-list.h
index 13f44c3a..54aab123 100644
--- a/btrfs-list.h
+++ b/btrfs-list.h
@@ -142,6 +142,7 @@ enum btrfs_list_filter_enum {
BTRFS_LIST_FILTER_FULL_PATH,
BTRFS_LIST_FILTER_BY_PARENT,
BTRFS_LIST_FILTER_DELETED,
+ BTRFS_LIST_FILTER_PARENT_SUBVOL_ONLY,
BTRFS_LIST_FILTER_MAX,
};
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index e7ef67d3..2371338e 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -404,6 +404,7 @@ static const char * const cmd_subvol_list_usage[] = {
"-q print the parent uuid of the snapshots",
"-R print the uuid of the received snapshots",
"-t print the result as a table",
+ "-P list parent subvolumes only",
"-s list snapshots only in the filesystem",
"-r list readonly subvolumes (including snapshots)",
"-d list deleted subvolumes that are not yet cleaned",
@@ -445,7 +446,7 @@ static int cmd_subvol_list(int argc, char **argv)
};
c = getopt_long(argc, argv,
- "acdgopqsurRG:C:t", long_options, NULL);
+ "acdgopPqsurRG:C:t", long_options, NULL);
if (c < 0)
break;
@@ -473,6 +474,11 @@ static int cmd_subvol_list(int argc, char **argv)
case 't':
is_tab_result = 1;
break;
+ case 'P':
+ btrfs_list_setup_filter(&filter_set,
+ BTRFS_LIST_FILTER_PARENT_SUBVOL_ONLY,
+ 0);
+ break;
case 's':
btrfs_list_setup_filter(&filter_set,
BTRFS_LIST_FILTER_SNAPSHOT_ONLY,
--
2.14.2
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