In command "btrfs subvolume set-default", we used subvolume <id> and <path>
to set the default subvolume of a filesystem. It's not easy for a common
user, so I improved it and the <fullpath> of a subvolume can be used to
set the default subvolume of a filesystem.
Signed-off-by: Cheng Yang <chenyang.fnst@xxxxxxxxxxxxxx>
---
cmds-subvolume.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++--------
man/btrfs.8.in | 6 ++--
2 files changed, 79 insertions(+), 16 deletions(-)
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 8399e72..827234c 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -26,6 +26,7 @@
#include <getopt.h>
#include "kerncompat.h"
+#include "ctree.h"
#include "ioctl.h"
#include "qgroup.h"
@@ -601,23 +602,66 @@ static int cmd_subvol_get_default(int argc, char **argv)
}
static const char * const cmd_subvol_set_default_usage[] = {
- "btrfs subvolume set-default <subvolid> <path>",
+ "btrfs subvolume set-default [-p] [<subvolid>] <path>",
"Set the default subvolume of a filesystem",
+ "-p Set the parent tree(subvolume) of the PATH",
+ " as the default subvolume, if PATH is not a subvolume",
NULL
};
static int cmd_subvol_set_default(int argc, char **argv)
{
- int ret=0, fd, e;
- u64 objectid;
+ int ret = 0, fd = -1, e;
+ int parent = 0;
+ u64 objectid = -1;
char *path;
- char *subvolid;
+ char *subvolid, *inv;
- if (check_argc_exact(argc, 3))
+ optind = 1;
+ while (1) {
+ int c = getopt(argc, argv, "p");
+ if (c < 0)
+ break;
+
+ switch (c) {
+ case 'p':
+ parent = 1;
+ break;
+ default:
+ usage(cmd_subvol_set_default_usage);
+ }
+ }
+
+ if (check_argc_min(argc - optind, 1) ||
+ check_argc_max(argc - optind, 2))
usage(cmd_subvol_set_default_usage);
- subvolid = argv[1];
- path = argv[2];
+ if (argc - optind == 2) {
+ subvolid = argv[optind];
+ path = argv[optind + 1];
+
+ objectid = (unsigned long long)strtoll(subvolid, &inv, 0);
+ if (errno == ERANGE || subvolid == inv) {
+ fprintf(stderr,
+ "ERROR: invalid tree id (%s)\n", subvolid);
+ return 30;
+ }
+ } else {
+ path = argv[optind];
+
+ ret = test_issubvolume(path);
+ if (ret < 0) {
+ fprintf(stderr,
+ "ERROR: error accessing '%s'\n", path);
+ return 12;
+ }
+ if (!ret && !parent) {
+ fprintf(stderr,
+ "ERROR: '%s' is not a subvolume\n",
+ path);
+ return 13;
+ }
+ }
fd = open_file_or_dir(path);
if (fd < 0) {
@@ -625,16 +669,35 @@ static int cmd_subvol_set_default(int argc, char **argv)
return 12;
}
- objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
- if (errno == ERANGE) {
- fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
- return 30;
+ /*
+ When objectid is -1, it means that
+ subvolume id is not specified by user.
+ We will set default subvolume by <path>.
+ */
+ if (objectid == -1) {
+ struct btrfs_ioctl_ino_lookup_args args;
+
+ memset(&args, 0, sizeof(args));
+ args.treeid = 0;
+ args.objectid = BTRFS_FIRST_FREE_OBJECTID;
+
+ ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
+ if (ret) {
+ fprintf(stderr,
+ "ERROR: can't perform the search - %s\n",
+ strerror(errno));
+ return ret;
+ }
+
+ objectid = args.treeid;
}
+
ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
e = errno;
close(fd);
- if( ret < 0 ){
- fprintf(stderr, "ERROR: unable to set a new default subvolume - %s\n",
+ if (ret < 0) {
+ fprintf(stderr,
+ "ERROR: unable to set a new default subvolume - %s\n",
strerror(e));
return 30;
}
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 3f7765d..2bc1d97 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -13,7 +13,7 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBsubvolume list\fP\fI [-pr] [-s 0|1] [-g [+|-]value] [-c [+|-]value] [--rootid=rootid,gen,ogen,path] <path>\fP
.PP
-\fBbtrfs\fP \fBsubvolume set-default\fP\fI <id> <path>\fP
+\fBbtrfs\fP \fBsubvolume set-default\fP\fI [-p] [<id>] <path>\fP
.PP
\fBbtrfs\fP \fBsubvolume get-default\fP\fI <path>\fP
.PP
@@ -147,9 +147,9 @@ for \fB--sort\fP you can combine some items together by ',', just like
.RE
.TP
-\fBsubvolume set-default\fR\fI <id> <path>\fR
+\fBsubvolume set-default\fR\fI [-p] [<id>] <path>\fR
Set the subvolume of the filesystem \fI<path>\fR which is mounted as
-\fIdefault\fR. The subvolume is identified by \fI<id>\fR, which
+\fIdefault\fR. The subvolume is identified by \fI<path>\fR or by \fI<id>\fR, which
is returned by the \fBsubvolume list\fR command.
.TP
--
1.7.7.6
--
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