This introduces a new btrfsctl option, -m, to allow you to set the default'ly
mounted subvolume. You can do
btrfsctl -m /your/subvolume
and that will make that subvolume the subvolume that is mounted by default, or
you can do
btrfsctl -m <treeid> /any/subvolume
and this will make the subvolume with tree id <treeid> the default'ly mounted
subvolume. You can get the treeid by using the listing option. Thanks,
Signed-off-by: Josef Bacik <jo...@redhat.com>
---
btrfsctl.c | 17 +++++++++++++++++
ioctl.h | 2 ++
2 files changed, 19 insertions(+), 0 deletions(-)
diff --git a/btrfsctl.c b/btrfsctl.c
index 064c0d0..81d2a30 100644
--- a/btrfsctl.c
+++ b/btrfsctl.c
@@ -29,6 +29,7 @@
#include <unistd.h>
#include <dirent.h>
#include <libgen.h>
+#include <stdlib.h>
#include "kerncompat.h"
#include "ctree.h"
#include "transaction.h"
@@ -58,6 +59,8 @@ static void print_usage(void)
printf("\t-c: forces a single FS sync\n");
printf("\t-D: delete snapshot\n");
printf("\t-l file: listing snapshot/subvolume under a subvolume\n");
+ printf("\t-m [tree id] directory: set the default mounted subvolume"
+ " to the [tree id] or the directory\n");
printf("%s\n", BTRFS_BUILD_VERSION);
exit(1);
}
@@ -266,6 +269,7 @@ int main(int ac, char **av)
unsigned long command = 0;
int len;
char *fullpath;
+ u64 objectid = 0;
if (ac == 2 && strcmp(av[1], "-a") == 0) {
fprintf(stderr, "Scanning for Btrfs filesystems\n");
@@ -380,6 +384,16 @@ int main(int ac, char **av)
exit(1);
}
command = BTRFS_IOC_SNAP_LISTING;
+ } else if (strcmp(av[i], "-m") == 0) {
+ command = BTRFS_IOC_DEFAULT_SUBVOL;
+ if (i == ac - 3) {
+ objectid = (unsigned long long)
+ strtoll(av[i + 1], NULL, 0);
+ if (errno == ERANGE) {
+ fprintf(stderr, "invalid tree id\n");
+ exit(1);
+ }
+ }
}
}
if (command == 0) {
@@ -410,6 +424,9 @@ int main(int ac, char **av)
ret = ioctl(snap_fd, command, &args);
} else if (command == BTRFS_IOC_SNAP_LISTING) {
ret = btrfs_list_subvolumes(snap_fd, command);
+ } else if (command == BTRFS_IOC_DEFAULT_SUBVOL) {
+ printf("objectid is %llu\n", objectid);
+ ret = ioctl(fd, command, &objectid);
} else
ret = ioctl(fd, command, &args);
if (ret < 0) {
diff --git a/ioctl.h b/ioctl.h
index 19020cb..70fc15d 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -91,4 +91,6 @@ struct btrfs_ioctl_subvol_leaf {
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SNAP_LISTING _IOWR(BTRFS_IOCTL_MAGIC, 16, \
struct btrfs_ioctl_subvol_args)
+#define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 17, u64)
+
#endif
--
1.5.4.3
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