btrfs-progs/props.c

195 lines
4.3 KiB
C

/*
* 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 <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <fcntl.h>
#include <unistd.h>
#include "ctree.h"
#include "commands.h"
#include "utils.h"
#include "props.h"
#define XATTR_BTRFS_PREFIX "btrfs."
#define XATTR_BTRFS_PREFIX_LEN (sizeof(XATTR_BTRFS_PREFIX) - 1)
/*
* Defined as synonyms in attr/xattr.h
*/
#ifndef ENOATTR
#define ENOATTR ENODATA
#endif
static int prop_read_only(enum prop_object_type type,
const char *object,
const char *name,
const char *value)
{
int ret = 0;
int fd = -1;
u64 flags = 0;
fd = open(object, O_RDONLY);
if (fd < 0) {
ret = -errno;
error("failed to open %s: %s", object, strerror(-ret));
goto out;
}
ret = ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags);
if (ret < 0) {
ret = -errno;
error("failed to get flags for %s: %s", object,
strerror(-ret));
goto out;
}
if (!value) {
if (flags & BTRFS_SUBVOL_RDONLY)
fprintf(stdout, "ro=true\n");
else
fprintf(stdout, "ro=false\n");
ret = 0;
goto out;
}
if (!strcmp(value, "true")) {
flags |= BTRFS_SUBVOL_RDONLY;
} else if (!strcmp(value, "false")) {
flags = flags & ~BTRFS_SUBVOL_RDONLY;
} else {
ret = -EINVAL;
error("invalid value for property: %s", value);
goto out;
}
ret = ioctl(fd, BTRFS_IOC_SUBVOL_SETFLAGS, &flags);
if (ret < 0) {
ret = -errno;
error("failed to set flags for %s: %s", object,
strerror(-ret));
goto out;
}
out:
if (fd != -1)
close(fd);
return ret;
}
static int prop_label(enum prop_object_type type,
const char *object,
const char *name,
const char *value)
{
int ret;
if (value) {
ret = set_label((char *) object, (char *) value);
} else {
char label[BTRFS_LABEL_SIZE];
ret = get_label((char *) object, label);
if (!ret)
fprintf(stdout, "label=%s\n", label);
}
return ret;
}
static int prop_compression(enum prop_object_type type,
const char *object,
const char *name,
const char *value)
{
int ret;
ssize_t sret;
int fd = -1;
DIR *dirstream = NULL;
char *buf = NULL;
char *xattr_name = NULL;
int open_flags = value ? O_RDWR : O_RDONLY;
fd = open_file_or_dir3(object, &dirstream, open_flags);
if (fd == -1) {
ret = -errno;
error("failed to open %s: %s", object, strerror(-ret));
goto out;
}
xattr_name = malloc(XATTR_BTRFS_PREFIX_LEN + strlen(name) + 1);
if (!xattr_name) {
ret = -ENOMEM;
goto out;
}
memcpy(xattr_name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN);
memcpy(xattr_name + XATTR_BTRFS_PREFIX_LEN, name, strlen(name));
xattr_name[XATTR_BTRFS_PREFIX_LEN + strlen(name)] = '\0';
if (value)
sret = fsetxattr(fd, xattr_name, value, strlen(value), 0);
else
sret = fgetxattr(fd, xattr_name, NULL, 0);
if (sret < 0) {
ret = -errno;
if (ret != -ENOATTR)
error("failed to %s compression for %s: %s",
value ? "set" : "get", object, strerror(-ret));
else
ret = 0;
goto out;
}
if (!value) {
size_t len = sret;
buf = malloc(len);
if (!buf) {
ret = -ENOMEM;
goto out;
}
sret = fgetxattr(fd, xattr_name, buf, len);
if (sret < 0) {
ret = -errno;
error("failed to get compression for %s: %s",
object, strerror(-ret));
goto out;
}
fprintf(stdout, "compression=%.*s\n", (int)len, buf);
}
ret = 0;
out:
free(xattr_name);
free(buf);
if (fd >= 0)
close_file_or_dir(fd, dirstream);
return ret;
}
const struct prop_handler prop_handlers[] = {
{"ro", "Set/get read-only flag of subvolume.", 0, prop_object_subvol,
prop_read_only},
{"label", "Set/get label of device.", 0,
prop_object_dev | prop_object_root, prop_label},
{"compression", "Set/get compression for a file or directory", 0,
prop_object_inode, prop_compression},
{NULL, NULL, 0, 0, NULL}
};