btrfs-progs/btrfsctl.c
Eric Sandeen bcb2b73358 btrfs-progs: simplify ioctl name copy and null termination
In the places where we copy a string into the name
member of btrfs_ioctl_vol_args or btrfs_ioctl_vol_args_v2,
we use strncopy (to not overflow the name array) and then
set the last position to the null character.

Howver, in both cases the arrays are defined with:

        char name[MAX+1];

hence the last array position is name[MAX].

In most cases, we now insert the null at name[MAX-1]
which deprives us of one useful character.

Even the above isn't consistent through the code, so
make some helper code to make it simple, i.e.
strncpy_null(dest, src) which automatically does the
right thing based on the size of dest.

Thanks to Zach Brown for the macro suggestion.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
2013-02-05 16:09:41 -08:00

274 lines
6.6 KiB
C

/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* 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.
*/
#ifndef __CHECKER__
#include <sys/ioctl.h>
#include <sys/mount.h>
#include "ioctl.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <libgen.h>
#include <stdlib.h>
#include "kerncompat.h"
#include "ctree.h"
#include "transaction.h"
#include "utils.h"
#include "version.h"
#ifdef __CHECKER__
#define BLKGETSIZE64 0
#define BTRFS_IOC_SNAP_CREATE 0
#define BTRFS_VOL_NAME_MAX 255
struct btrfs_ioctl_vol_args { char name[BTRFS_VOL_NAME_MAX]; };
static inline int ioctl(int fd, int define, void *arg) { return 0; }
#endif
static void print_usage(void)
{
printf("usage: btrfsctl [ -d file|dir] [ -s snap_name subvol|tree ]\n");
printf(" [-r size] [-A device] [-a] [-c] [-D dir .]\n");
printf("\t-d filename: defragments one file\n");
printf("\t-d directory: defragments the entire Btree\n");
printf("\t-s snap_name dir: creates a new snapshot of dir\n");
printf("\t-S subvol_name dir: creates a new subvolume\n");
printf("\t-r [+-]size[gkm]: resize the FS by size amount\n");
printf("\t-A device: scans the device file for a Btrfs filesystem\n");
printf("\t-a: scans all devices for Btrfs filesystems\n");
printf("\t-c: forces a single FS sync\n");
printf("\t-D: delete snapshot\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);
}
static int btrfsctl_open_file_or_dir(const char *fname)
{
int ret;
struct stat st;
DIR *dirstream;
int fd;
ret = stat(fname, &st);
if (ret < 0) {
perror("stat:");
exit(1);
}
if (S_ISDIR(st.st_mode)) {
dirstream = opendir(fname);
if (!dirstream) {
perror("opendir");
exit(1);
}
fd = dirfd(dirstream);
} else {
fd = open(fname, O_RDWR);
}
if (fd < 0) {
perror("open");
exit(1);
}
return fd;
}
int main(int ac, char **av)
{
char *fname = NULL;
char *snap_location = NULL;
int snap_fd = 0;
int fd;
int ret;
struct btrfs_ioctl_vol_args args;
char *name = NULL;
int i;
unsigned long command = 0;
int len;
char *pos;
char *fullpath;
u64 objectid = 0;
printf( "**\n"
"** WARNING: this program is considered deprecated\n"
"** Please consider to switch to the btrfs utility\n"
"**\n");
if (ac == 2 && strcmp(av[1], "-a") == 0) {
fprintf(stderr, "Scanning for Btrfs filesystems\n");
btrfs_scan_one_dir("/dev", 1);
exit(0);
}
for (i = 1; i < ac; i++) {
if (strcmp(av[i], "-s") == 0) {
if (i + 1 >= ac - 1) {
fprintf(stderr, "-s requires an arg");
print_usage();
}
fullpath = av[i + 1];
snap_location = strdup(fullpath);
snap_location = dirname(snap_location);
snap_fd = btrfsctl_open_file_or_dir(snap_location);
name = strdup(fullpath);
name = basename(name);
len = strlen(name);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr,
"snapshot name zero length or too long\n");
exit(1);
}
if (strchr(name, '/')) {
fprintf(stderr,
"error: / not allowed in names\n");
exit(1);
}
command = BTRFS_IOC_SNAP_CREATE;
} else if (strcmp(av[i], "-S") == 0) {
if (i + 1 >= ac - 1) {
fprintf(stderr, "-S requires an arg");
print_usage();
}
name = av[i + 1];
len = strlen(name);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr,
"snapshot name zero length or too long\n");
exit(1);
}
if (strchr(name, '/')) {
fprintf(stderr,
"error: / not allowed in names\n");
exit(1);
}
command = BTRFS_IOC_SUBVOL_CREATE;
} else if (strcmp(av[i], "-d") == 0) {
if (i >= ac - 1) {
fprintf(stderr, "-d requires an arg\n");
print_usage();
}
command = BTRFS_IOC_DEFRAG;
} else if (strcmp(av[i], "-D") == 0) {
if (i >= ac - 1) {
fprintf(stderr, "-D requires an arg\n");
print_usage();
}
command = BTRFS_IOC_SNAP_DESTROY;
name = av[i + 1];
len = strlen(name);
pos = strchr(name, '/');
if (pos) {
if (*(pos + 1) == '\0')
*(pos) = '\0';
else {
fprintf(stderr,
"error: / not allowed in names\n");
exit(1);
}
}
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr, "-D size too long\n");
exit(1);
}
} else if (strcmp(av[i], "-A") == 0) {
if (i >= ac - 1) {
fprintf(stderr, "-A requires an arg\n");
print_usage();
}
command = BTRFS_IOC_SCAN_DEV;
} else if (strcmp(av[i], "-r") == 0) {
if (i >= ac - 1) {
fprintf(stderr, "-r requires an arg\n");
print_usage();
}
name = av[i + 1];
len = strlen(name);
if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
fprintf(stderr, "-r size too long\n");
exit(1);
}
command = BTRFS_IOC_RESIZE;
} else if (strcmp(av[i], "-c") == 0) {
command = BTRFS_IOC_SYNC;
} 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) {
fprintf(stderr, "no valid commands given\n");
print_usage();
exit(1);
}
fname = av[ac - 1];
if (command == BTRFS_IOC_SCAN_DEV) {
fd = open("/dev/btrfs-control", O_RDWR);
if (fd < 0) {
perror("failed to open /dev/btrfs-control");
exit(1);
}
name = fname;
} else {
fd = btrfsctl_open_file_or_dir(fname);
}
if (name)
strncpy_null(args.name, name);
else
args.name[0] = '\0';
if (command == BTRFS_IOC_SNAP_CREATE) {
args.fd = fd;
ret = ioctl(snap_fd, command, &args);
} else if (command == BTRFS_IOC_DEFAULT_SUBVOL) {
printf("objectid is %llu\n", (unsigned long long)objectid);
ret = ioctl(fd, command, &objectid);
} else
ret = ioctl(fd, command, &args);
if (ret < 0) {
perror("ioctl:");
exit(1);
}
if (ret == 0) {
printf("operation complete\n");
} else {
printf("ioctl failed with error %d\n", ret);
}
printf("%s\n", BTRFS_BUILD_VERSION);
if (ret)
exit(1);
return 0;
}