btrfs-progs/cmds-subvolume.c

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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <sys/stat.h>
#include <libgen.h>
#include <limits.h>
#include "kerncompat.h"
#include "ioctl.h"
#include "qgroup.h"
#include "commands.h"
/* btrfs-list.c */
int list_subvols(int fd, int print_parent, int get_default);
int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
static const char * const subvolume_cmd_group_usage[] = {
"btrfs subvolume <command> <args>",
NULL
};
/*
* test if path is a directory
* this function return
* 0-> path exists but it is not a directory
* 1-> path exists and it is a directory
* -1 -> path is unaccessible
*/
static int test_isdir(char *path)
{
struct stat st;
int res;
res = stat(path, &st);
if(res < 0 )
return -1;
return S_ISDIR(st.st_mode);
}
static const char * const cmd_subvol_create_usage[] = {
"btrfs subvolume create [<dest>/]<name>",
"Create a subvolume",
"Create a subvolume <name> in <dest>. If <dest> is not given",
"subvolume <name> will be created in the current directory.",
NULL
};
static int cmd_subvol_create(int argc, char **argv)
{
int res, fddst, len, e;
char *newname;
char *dstdir;
char *dst;
struct btrfs_qgroup_inherit *inherit = NULL;
optind = 1;
while (1) {
int c = getopt(argc, argv, "c:i:r");
if (c < 0)
break;
switch (c) {
case 'c':
res = qgroup_inherit_add_copy(&inherit, optarg, 0);
if (res)
return res;
break;
case 'i':
res = qgroup_inherit_add_group(&inherit, optarg);
if (res)
return res;
break;
default:
usage(cmd_subvol_create_usage);
}
}
if (check_argc_exact(argc - optind, 1))
usage(cmd_subvol_create_usage);
dst = argv[optind];
res = test_isdir(dst);
if(res >= 0 ){
fprintf(stderr, "ERROR: '%s' exists\n", dst);
return 12;
}
newname = strdup(dst);
newname = basename(newname);
dstdir = strdup(dst);
dstdir = dirname(dstdir);
if( !strcmp(newname,".") || !strcmp(newname,"..") ||
strchr(newname, '/') ){
fprintf(stderr, "ERROR: uncorrect subvolume name ('%s')\n",
newname);
return 14;
}
len = strlen(newname);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr, "ERROR: subvolume name too long ('%s)\n",
newname);
return 14;
}
fddst = open_file_or_dir(dstdir);
if (fddst < 0) {
fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
return 12;
}
printf("Create subvolume '%s/%s'\n", dstdir, newname);
if (inherit) {
struct btrfs_ioctl_vol_args_v2 args;
memset(&args, 0, sizeof(args));
strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
args.size = qgroup_inherit_size(inherit);
args.qgroup_inherit = inherit;
res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE_V2, &args);
} else {
struct btrfs_ioctl_vol_args args;
memset(&args, 0, sizeof(args));
strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
}
e = errno;
close(fddst);
if(res < 0 ){
fprintf( stderr, "ERROR: cannot create subvolume - %s\n",
strerror(e));
return 11;
}
free(inherit);
return 0;
}
/*
* test if path is a subvolume:
* this function return
* 0-> path exists but it is not a subvolume
* 1-> path exists and it is a subvolume
* -1 -> path is unaccessible
*/
int test_issubvolume(char *path)
{
struct stat st;
int res;
res = stat(path, &st);
if(res < 0 )
return -1;
return (st.st_ino == 256) && S_ISDIR(st.st_mode);
}
static const char * const cmd_subvol_delete_usage[] = {
"btrfs subvolume delete <name>",
"Delete a subvolume",
NULL
};
static int cmd_subvol_delete(int argc, char **argv)
{
int res, fd, len, e;
struct btrfs_ioctl_vol_args args;
char *dname, *vname, *cpath;
char *path;
if (check_argc_exact(argc, 2))
usage(cmd_subvol_delete_usage);
path = argv[1];
res = test_issubvolume(path);
if(res<0){
fprintf(stderr, "ERROR: error accessing '%s'\n", path);
return 12;
}
if(!res){
fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
return 13;
}
cpath = realpath(path, 0);
dname = strdup(cpath);
dname = dirname(dname);
vname = strdup(cpath);
vname = basename(vname);
free(cpath);
if( !strcmp(vname,".") || !strcmp(vname,"..") ||
strchr(vname, '/') ){
fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
vname);
return 14;
}
len = strlen(vname);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
vname);
return 14;
}
fd = open_file_or_dir(dname);
if (fd < 0) {
close(fd);
fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
return 12;
}
printf("Delete subvolume '%s/%s'\n", dname, vname);
strncpy(args.name, vname, BTRFS_PATH_NAME_MAX);
args.name[BTRFS_PATH_NAME_MAX-1] = 0;
res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
e = errno;
close(fd);
if(res < 0 ){
fprintf( stderr, "ERROR: cannot delete '%s/%s' - %s\n",
dname, vname, strerror(e));
return 11;
}
return 0;
}
static const char * const cmd_subvol_list_usage[] = {
"btrfs subvolume list [-p] <path>",
"List subvolumes (and snapshots)",
"",
"-p print parent ID",
NULL
};
static int cmd_subvol_list(int argc, char **argv)
{
int fd;
int ret;
int print_parent = 0;
char *subvol;
optind = 1;
while(1) {
int c = getopt(argc, argv, "p");
if (c < 0)
break;
switch(c) {
case 'p':
print_parent = 1;
break;
default:
usage(cmd_subvol_list_usage);
}
}
if (check_argc_exact(argc - optind, 1))
usage(cmd_subvol_list_usage);
subvol = argv[optind];
ret = test_issubvolume(subvol);
if (ret < 0) {
fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
return 12;
}
if (!ret) {
fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
return 13;
}
fd = open_file_or_dir(subvol);
if (fd < 0) {
fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
return 12;
}
ret = list_subvols(fd, print_parent, 0);
if (ret)
return 19;
return 0;
}
static const char * const cmd_snapshot_usage[] = {
"btrfs subvolume snapshot [-r] <source> [<dest>/]<name>",
"Create a snapshot of the subvolume",
"Create a writable/readonly snapshot of the subvolume <source> with",
"the name <name> in the <dest> directory",
"",
"-r create a readonly snapshot",
NULL
};
static int cmd_snapshot(int argc, char **argv)
{
char *subvol, *dst;
int res, fd, fddst, len, e, readonly = 0;
char *newname;
char *dstdir;
struct btrfs_ioctl_vol_args_v2 args;
struct btrfs_qgroup_inherit *inherit = NULL;
optind = 1;
memset(&args, 0, sizeof(args));
while (1) {
int c = getopt(argc, argv, "c:i:r");
if (c < 0)
break;
switch (c) {
case 'c':
res = qgroup_inherit_add_copy(&inherit, optarg, 0);
if (res)
return res;
break;
case 'i':
res = qgroup_inherit_add_group(&inherit, optarg);
if (res)
return res;
break;
case 'r':
readonly = 1;
break;
case 'x':
res = qgroup_inherit_add_copy(&inherit, optarg, 1);
if (res)
return res;
break;
default:
usage(cmd_snapshot_usage);
}
}
if (check_argc_exact(argc - optind, 2))
usage(cmd_snapshot_usage);
subvol = argv[optind];
dst = argv[optind + 1];
res = test_issubvolume(subvol);
if(res<0){
fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
return 12;
}
if(!res){
fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
return 13;
}
res = test_isdir(dst);
if(res == 0 ){
fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
return 12;
}
if(res>0){
newname = strdup(subvol);
newname = basename(newname);
dstdir = dst;
}else{
newname = strdup(dst);
newname = basename(newname);
dstdir = strdup(dst);
dstdir = dirname(dstdir);
}
if( !strcmp(newname,".") || !strcmp(newname,"..") ||
strchr(newname, '/') ){
fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
newname);
return 14;
}
len = strlen(newname);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
newname);
return 14;
}
fddst = open_file_or_dir(dstdir);
if (fddst < 0) {
fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
return 12;
}
fd = open_file_or_dir(subvol);
if (fd < 0) {
close(fddst);
fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
return 12;
}
if (readonly) {
args.flags |= BTRFS_SUBVOL_RDONLY;
printf("Create a readonly snapshot of '%s' in '%s/%s'\n",
subvol, dstdir, newname);
} else {
printf("Create a snapshot of '%s' in '%s/%s'\n",
subvol, dstdir, newname);
}
args.fd = fd;
if (inherit) {
args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
args.size = qgroup_inherit_size(inherit);
args.qgroup_inherit = inherit;
}
strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
e = errno;
close(fd);
close(fddst);
if(res < 0 ){
fprintf( stderr, "ERROR: cannot snapshot '%s' - %s\n",
subvol, strerror(e));
return 11;
}
free(inherit);
return 0;
}
static const char * const cmd_subvol_get_default_usage[] = {
"btrfs subvolume get-default <path>",
"Get the default subvolume of a filesystem",
NULL
};
static int cmd_subvol_get_default(int argc, char **argv)
{
int fd;
int ret;
char *subvol;
if (check_argc_exact(argc, 2))
usage(cmd_subvol_get_default_usage);
subvol = argv[1];
ret = test_issubvolume(subvol);
if (ret < 0) {
fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
return 12;
}
if (!ret) {
fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
return 13;
}
fd = open_file_or_dir(subvol);
if (fd < 0) {
fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
return 12;
}
ret = list_subvols(fd, 0, 1);
if (ret)
return 19;
return 0;
}
static const char * const cmd_subvol_set_default_usage[] = {
"btrfs subvolume set-default <subvolid> <path>",
"Set the default subvolume of a filesystem",
NULL
};
static int cmd_subvol_set_default(int argc, char **argv)
{
int ret=0, fd, e;
u64 objectid;
char *path;
char *subvolid;
if (check_argc_exact(argc, 3))
usage(cmd_subvol_set_default_usage);
subvolid = argv[1];
path = argv[2];
fd = open_file_or_dir(path);
if (fd < 0) {
fprintf(stderr, "ERROR: can't access to '%s'\n", path);
return 12;
}
objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
if (errno == ERANGE) {
fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
return 30;
}
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",
strerror(e));
return 30;
}
return 0;
}
static const char * const cmd_find_new_usage[] = {
"btrfs subvolume find-new <path> <lastgen>",
"List the recently modified files in a filesystem",
NULL
};
static int cmd_find_new(int argc, char **argv)
{
int fd;
int ret;
char *subvol;
u64 last_gen;
if (check_argc_exact(argc, 3))
usage(cmd_find_new_usage);
subvol = argv[1];
last_gen = atoll(argv[2]);
ret = test_issubvolume(subvol);
if (ret < 0) {
fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
return 12;
}
if (!ret) {
fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
return 13;
}
fd = open_file_or_dir(subvol);
if (fd < 0) {
fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
return 12;
}
ret = find_updated_files(fd, 0, last_gen);
if (ret)
return 19;
return 0;
}
const struct cmd_group subvolume_cmd_group = {
subvolume_cmd_group_usage, NULL, {
{ "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
{ "delete", cmd_subvol_delete, cmd_subvol_delete_usage, NULL, 0 },
{ "list", cmd_subvol_list, cmd_subvol_list_usage, NULL, 0 },
{ "snapshot", cmd_snapshot, cmd_snapshot_usage, NULL, 0 },
{ "get-default", cmd_subvol_get_default,
cmd_subvol_get_default_usage, NULL, 0 },
{ "set-default", cmd_subvol_set_default,
cmd_subvol_set_default_usage, NULL, 0 },
{ "find-new", cmd_find_new, cmd_find_new_usage, NULL, 0 },
{ 0, 0, 0, 0, 0 }
}
};
int cmd_subvolume(int argc, char **argv)
{
return handle_command_group(&subvolume_cmd_group, argc, argv);
}