Change the default behavior of "subvolume list" and allow non-privileged
user to call it as well.
>From this commit, by default it only lists subvolumes under the specified
path (incl. the path itself except top-level subvolume). Also, if kernel
supports new ioctls (BTRFS_IOC_GET_SUBVOL_INFO/BTRFS_IOC_GET_ROOTREF/
BTRFS_IOC_INO_LOOKUP_USER),
- the specified path can be non-subvolume directory.
- non-privileged user can also call it.
Note that root user can list all the subvolume in the fs with -a option
(the same behavior as before).
Signed-off-by: Tomohiro Misono <misono.tomoh...@jp.fujitsu.com>
---
Documentation/btrfs-subvolume.asciidoc | 2 +
cmds-subvolume.c | 90 +++++++++++++++++++++++++++++-----
2 files changed, 81 insertions(+), 11 deletions(-)
diff --git a/Documentation/btrfs-subvolume.asciidoc
b/Documentation/btrfs-subvolume.asciidoc
index a8c4af4b..e03d4a6e 100644
--- a/Documentation/btrfs-subvolume.asciidoc
+++ b/Documentation/btrfs-subvolume.asciidoc
@@ -92,6 +92,7 @@ The output format is similar to *subvolume list* command.
*list* [options] [-G [\+|-]<value>] [-C [+|-]<value>]
[--sort=rootid,gen,ogen,path] <path>::
List the subvolumes present in the filesystem <path>.
+By default, this lists the subvolume under the specified path.
+
For every subvolume the following information is shown by default. +
ID <ID> top level <ID> path <path> +
@@ -109,6 +110,7 @@ print parent ID.
-a::::
print all the subvolumes in the filesystem and distinguish between
absolute and relative path with respect to the given <path>.
+This requires root privileges.
-c::::
print the ogeneration of the subvolume, aliases: ogen or origin generation.
-g::::
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 06686943..c3952172 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -1126,6 +1126,7 @@ out:
}
static struct subvol_list *btrfs_list_subvols(int fd,
+ int is_list_all,
struct btrfs_list_filter_set_v2
*filter_set)
{
struct subvol_list *subvols;
@@ -1133,6 +1134,7 @@ static struct subvol_list *btrfs_list_subvols(int fd,
struct btrfs_util_subvolume_iterator *iter;
enum btrfs_util_error err;
int ret = -1;
+ int tree_id = 0;
subvols = malloc(sizeof(*subvols));
if (!subvols) {
@@ -1141,8 +1143,11 @@ static struct subvol_list *btrfs_list_subvols(int fd,
}
subvols->num = 0;
+ if (is_list_all)
+ tree_id = BTRFS_FS_TREE_OBJECTID;
+
err = btrfs_util_create_subvolume_iterator_fd(fd,
- BTRFS_FS_TREE_OBJECTID, 0,
+ tree_id, 0,
&iter);
if (err) {
iter = NULL;
@@ -1189,6 +1194,60 @@ static struct subvol_list *btrfs_list_subvols(int fd,
subvols->num++;
}
+ /*
+ * Subvolume iterator does not include the information of the
+ * specified path/fd. So, add it here.
+ */
+ if (!is_list_all) {
+ uint64_t id;
+ struct listed_subvol subvol;
+
+ err = btrfs_util_is_subvolume_fd(fd);
+ if (err != BTRFS_UTIL_OK) {
+ if (err == BTRFS_UTIL_ERROR_NOT_SUBVOLUME)
+ ret = 0;
+ goto out;
+ }
+ err = btrfs_util_subvolume_id_fd(fd, &id);
+ if (err)
+ goto out;
+ if (id == BTRFS_FS_TREE_OBJECTID) {
+ /* Skip top level subvolume */
+ ret = 0;
+ goto out;
+ }
+
+ err = btrfs_util_subvolume_info_fd(fd, 0, &subvol.info);
+ if (err)
+ goto out;
+
+ subvol.path = strdup(".");
+ if (!filters_match(&subvol, filter_set)) {
+ free(subvol.path);
+ } else {
+ if (subvols->num >= capacity) {
+ struct subvol_list *new_subvols;
+ size_t new_capacity =
+ max_t(size_t, 1, capacity * 2);
+
+ new_subvols = realloc(subvols,
+ sizeof(*new_subvols) +
+ new_capacity *
+ sizeof(new_subvols->subvols[0]));
+ if (!new_subvols) {
+ error("out of memory");
+ goto out;
+ }
+
+ subvols = new_subvols;
+ capacity = new_capacity;
+ }
+
+ subvols->subvols[subvols->num] = subvol;
+ subvols->num++;
+ }
+ }
+
ret = 0;
out:
if (iter)
@@ -1202,20 +1261,14 @@ static int btrfs_list_subvols_print_v2(int fd,
struct btrfs_list_filter_set_v2 *filter_set,
struct btrfs_list_comparer_set_v2 *comp_set,
enum btrfs_list_layout layout,
- int full_path, const char *raw_prefix)
+ int is_list_all, const char *raw_prefix)
{
struct subvol_list *subvols;
- /*
- * full_path hasn't done anything since 4f5ebb3ef553 ("Btrfs-progs: fix
- * to make list specified directory's subvolumes work"). See
- * https://www.spinics.net/lists/linux-btrfs/msg69820.html
- */
-
if (filter_set->only_deleted)
subvols = btrfs_list_deleted_subvols(fd, filter_set);
else
- subvols = btrfs_list_subvols(fd, filter_set);
+ subvols = btrfs_list_subvols(fd, is_list_all, filter_set);
if (!subvols)
return -1;
@@ -1311,6 +1364,14 @@ static int btrfs_list_parse_filter_string_v2(char
*opt_arg,
return 0;
}
+static bool is_root(void)
+{
+ uid_t uid;
+
+ uid = geteuid();
+ return (uid == 0);
+}
+
/*
* Naming of options:
* - uppercase for filters and sort options
@@ -1319,12 +1380,13 @@ static int btrfs_list_parse_filter_string_v2(char
*opt_arg,
static const char * const cmd_subvol_list_usage[] = {
"btrfs subvolume list [options] <path>",
"List subvolumes and snapshots in the filesystem.",
+ "By default, this only lists the subvolume under the specified path.",
"",
"Path filtering:",
"-o print only subvolumes below specified path",
"-a print all the subvolumes in the filesystem and",
" distinguish absolute and relative path with respect",
- " to the given <path>",
+ " to the given <path> (require root privileges)",
"",
"Field selection:",
"-p print parent ID",
@@ -1485,6 +1547,12 @@ static int cmd_subvol_list(int argc, char **argv)
if (ret)
goto out;
+ if (is_list_all && !is_root()) {
+ ret = -1;
+ error("Only root can use -a option");
+ goto out;
+ }
+
if (is_list_all)
btrfs_list_setup_filter_v2(&filter_set,
BTRFS_LIST_FILTER_FULL_PATH,
@@ -1501,7 +1569,7 @@ static int cmd_subvol_list(int argc, char **argv)
btrfs_list_setup_print_column_v2(BTRFS_LIST_PATH);
ret = btrfs_list_subvols_print_v2(fd, filter_set, comparer_set,
- layout, !is_list_all && !is_only_in_path, NULL);
+ layout, is_list_all, NULL);
out:
close_file_or_dir(fd, dirstream);
--
2.14.3
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