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https://git.proxmox.com/git/mirror_lxc
synced 2025-08-10 11:15:14 +00:00
Cleanup bdev.c after splitting into modules
The function - bdev_get(); becomes static. It is called from nowhere else so far and never appeared in any header. Minor changes - Avoid comparisons between int and size_t types. Use size_t where possible else cast to size_t when it makes sense. - insert missing spaces between operators - put declarations for all static functions at the top Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>
This commit is contained in:
Christian Brauner
parent
bf76c012b3
commit
cdb4e53a7d
@ -189,12 +189,30 @@ static const struct bdev_ops zfs_ops = {
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.can_backup = true,
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.can_backup = true,
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};
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};
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struct bdev_type {
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const char *name;
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const struct bdev_ops *ops;
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};
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static const struct bdev_type bdevs[] = {
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{.name = "zfs", .ops = &zfs_ops,},
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{.name = "lvm", .ops = &lvm_ops,},
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{.name = "rbd", .ops = &rbd_ops,},
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{.name = "btrfs", .ops = &btrfs_ops,},
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{.name = "dir", .ops = &dir_ops,},
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{.name = "aufs", .ops = &aufs_ops,},
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{.name = "overlayfs", .ops = &ovl_ops,},
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{.name = "loop", .ops = &loop_ops,},
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{.name = "nbd", .ops = &nbd_ops,},
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};
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static const size_t numbdevs = sizeof(bdevs) / sizeof(struct bdev_type);
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/* helpers */
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/* helpers */
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/*
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static const struct bdev_type *bdev_query(const char *src);
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* These are copied from conf.c. However as conf.c will be moved to using
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static struct bdev *bdev_get(const char *type);
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* the callback system, they can be pulled from there eventually, so we
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static struct bdev *do_bdev_create(const char *dest, const char *type,
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* don't need to pollute utils.c with these low level functions
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const char *cname, struct bdev_specs *specs);
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*/
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static int find_fstype_cb(char *buffer, void *data);
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static int find_fstype_cb(char *buffer, void *data);
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static char *linkderef(char *path, char *dest);
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static char *linkderef(char *path, char *dest);
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static bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
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static bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
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@ -233,8 +251,8 @@ char *dir_new_path(char *src, const char *oldname, const char *name,
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}
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}
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while ((p2 = strstr(src, oldname)) != NULL) {
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while ((p2 = strstr(src, oldname)) != NULL) {
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strncpy(p, src, p2-src); // copy text up to oldname
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strncpy(p, src, p2 - src); // copy text up to oldname
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p += p2-src; // move target pointer (p)
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p += p2 - src; // move target pointer (p)
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p += sprintf(p, "%s", name); // print new name in place of oldname
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p += sprintf(p, "%s", name); // print new name in place of oldname
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src = p2 + l2; // move src to end of oldname
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src = p2 + l2; // move src to end of oldname
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}
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}
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@ -243,369 +261,27 @@ char *dir_new_path(char *src, const char *oldname, const char *name,
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}
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}
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/*
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/*
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* return block size of dev->src in units of bytes
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* attach_block_device returns true if all went well,
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* meaning either a block device was attached or was not
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* needed. It returns false if something went wrong and
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* container startup should be stopped.
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*/
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*/
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int blk_getsize(struct bdev *bdev, uint64_t *size)
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bool attach_block_device(struct lxc_conf *conf)
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{
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{
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int fd, ret;
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char *path;
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char *path = bdev->src;
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if (strcmp(bdev->type, "loop") == 0)
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if (!conf->rootfs.path)
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path = bdev->src + 5;
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return true;
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path = conf->rootfs.path;
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fd = open(path, O_RDONLY);
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if (!requires_nbd(path))
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if (fd < 0)
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return true;
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return -1;
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path = strchr(path, ':');
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if (!path)
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ret = ioctl(fd, BLKGETSIZE64, size); // size of device in bytes
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return false;
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close(fd);
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path++;
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return ret;
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if (!attach_nbd(path, conf))
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}
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return false;
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return true;
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/*
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* These are copied from conf.c. However as conf.c will be moved to using
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* the callback system, they can be pulled from there eventually, so we
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* don't need to pollute utils.c with these low level functions
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*/
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static int find_fstype_cb(char* buffer, void *data)
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{
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struct cbarg {
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const char *rootfs;
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const char *target;
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const char *options;
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} *cbarg = data;
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unsigned long mntflags;
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char *mntdata;
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char *fstype;
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/* we don't try 'nodev' entries */
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if (strstr(buffer, "nodev"))
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return 0;
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fstype = buffer;
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fstype += lxc_char_left_gc(fstype, strlen(fstype));
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fstype[lxc_char_right_gc(fstype, strlen(fstype))] = '\0';
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DEBUG("trying to mount '%s'->'%s' with fstype '%s'",
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cbarg->rootfs, cbarg->target, fstype);
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if (parse_mntopts(cbarg->options, &mntflags, &mntdata) < 0) {
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free(mntdata);
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return 0;
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}
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if (mount(cbarg->rootfs, cbarg->target, fstype, mntflags, mntdata)) {
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DEBUG("mount failed with error: %s", strerror(errno));
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free(mntdata);
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return 0;
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}
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free(mntdata);
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INFO("mounted '%s' on '%s', with fstype '%s'",
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cbarg->rootfs, cbarg->target, fstype);
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return 1;
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}
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int mount_unknown_fs(const char *rootfs, const char *target,
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const char *options)
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{
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struct cbarg {
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const char *rootfs;
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const char *target;
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const char *options;
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} cbarg = {
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.rootfs = rootfs,
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.target = target,
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.options = options,
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};
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/*
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* find the filesystem type with brute force:
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* first we check with /etc/filesystems, in case the modules
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* are auto-loaded and fall back to the supported kernel fs
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*/
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char *fsfile[] = {
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"/etc/filesystems",
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"/proc/filesystems",
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};
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size_t i;
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for (i = 0; i < sizeof(fsfile)/sizeof(fsfile[0]); i++) {
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int ret;
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if (access(fsfile[i], F_OK))
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continue;
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ret = lxc_file_for_each_line(fsfile[i], find_fstype_cb, &cbarg);
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if (ret < 0) {
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ERROR("failed to parse '%s'", fsfile[i]);
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return -1;
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}
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if (ret)
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return 0;
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}
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ERROR("failed to determine fs type for '%s'", rootfs);
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return -1;
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}
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int do_mkfs(const char *path, const char *fstype)
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{
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pid_t pid;
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if ((pid = fork()) < 0) {
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ERROR("error forking");
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return -1;
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}
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if (pid > 0)
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return wait_for_pid(pid);
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// If the file is not a block device, we don't want mkfs to ask
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// us about whether to proceed.
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if (null_stdfds() < 0)
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exit(1);
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execlp("mkfs", "mkfs", "-t", fstype, path, NULL);
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exit(1);
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}
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static char *linkderef(char *path, char *dest)
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{
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struct stat sbuf;
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ssize_t ret;
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ret = stat(path, &sbuf);
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if (ret < 0)
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return NULL;
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if (!S_ISLNK(sbuf.st_mode))
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return path;
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ret = readlink(path, dest, MAXPATHLEN);
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if (ret < 0) {
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SYSERROR("error reading link %s", path);
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return NULL;
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} else if (ret >= MAXPATHLEN) {
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ERROR("link in %s too long", path);
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return NULL;
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}
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dest[ret] = '\0';
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return dest;
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}
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/*
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* Given a bdev (presumably blockdev-based), detect the fstype
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* by trying mounting (in a private mntns) it.
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* @bdev: bdev to investigate
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* @type: preallocated char* in which to write the fstype
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* @len: length of passed in char*
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* Returns length of fstype, of -1 on error
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*/
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int detect_fs(struct bdev *bdev, char *type, int len)
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{
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int p[2], ret;
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size_t linelen;
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pid_t pid;
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FILE *f;
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char *sp1, *sp2, *sp3, *line = NULL;
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char *srcdev;
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if (!bdev || !bdev->src || !bdev->dest)
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return -1;
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srcdev = bdev->src;
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if (strcmp(bdev->type, "loop") == 0)
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srcdev = bdev->src + 5;
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ret = pipe(p);
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if (ret < 0)
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return -1;
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if ((pid = fork()) < 0)
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return -1;
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if (pid > 0) {
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int status;
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close(p[1]);
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memset(type, 0, len);
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ret = read(p[0], type, len-1);
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close(p[0]);
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if (ret < 0) {
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SYSERROR("error reading from pipe");
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wait(&status);
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return -1;
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} else if (ret == 0) {
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ERROR("child exited early - fstype not found");
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wait(&status);
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return -1;
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}
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wait(&status);
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type[len-1] = '\0';
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INFO("detected fstype %s for %s", type, srcdev);
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return ret;
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}
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if (unshare(CLONE_NEWNS) < 0)
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exit(1);
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if (detect_shared_rootfs()) {
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if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL)) {
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SYSERROR("Failed to make / rslave");
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ERROR("Continuing...");
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}
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}
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ret = mount_unknown_fs(srcdev, bdev->dest, bdev->mntopts);
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if (ret < 0) {
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ERROR("failed mounting %s onto %s to detect fstype", srcdev, bdev->dest);
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exit(1);
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}
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// if symlink, get the real dev name
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char devpath[MAXPATHLEN];
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char *l = linkderef(srcdev, devpath);
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if (!l)
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exit(1);
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f = fopen("/proc/self/mounts", "r");
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if (!f)
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exit(1);
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while (getline(&line, &linelen, f) != -1) {
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sp1 = strchr(line, ' ');
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if (!sp1)
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exit(1);
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*sp1 = '\0';
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if (strcmp(line, l))
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continue;
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sp2 = strchr(sp1+1, ' ');
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if (!sp2)
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exit(1);
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*sp2 = '\0';
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sp3 = strchr(sp2+1, ' ');
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if (!sp3)
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exit(1);
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*sp3 = '\0';
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sp2++;
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if (write(p[1], sp2, strlen(sp2)) != strlen(sp2))
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exit(1);
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exit(0);
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}
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exit(1);
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}
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struct bdev_type {
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const char *name;
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const struct bdev_ops *ops;
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};
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// this will return 1 for physical disks, qemu-nbd, loop, etc
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// right now only lvm is a block device
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int is_blktype(struct bdev *b)
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{
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if (strcmp(b->type, "lvm") == 0)
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return 1;
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return 0;
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}
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static const struct bdev_type bdevs[] = {
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{.name = "zfs", .ops = &zfs_ops,},
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{.name = "lvm", .ops = &lvm_ops,},
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{.name = "rbd", .ops = &rbd_ops,},
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{.name = "btrfs", .ops = &btrfs_ops,},
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{.name = "dir", .ops = &dir_ops,},
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{.name = "aufs", .ops = &aufs_ops,},
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{.name = "overlayfs", .ops = &ovl_ops,},
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{.name = "loop", .ops = &loop_ops,},
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{.name = "nbd", .ops = &nbd_ops,},
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};
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static const size_t numbdevs = sizeof(bdevs) / sizeof(struct bdev_type);
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void bdev_put(struct bdev *bdev)
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{
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free(bdev->mntopts);
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free(bdev->src);
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free(bdev->dest);
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free(bdev);
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}
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struct bdev *bdev_get(const char *type)
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{
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int i;
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struct bdev *bdev;
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for (i=0; i<numbdevs; i++) {
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if (strcmp(bdevs[i].name, type) == 0)
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break;
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}
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if (i == numbdevs)
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return NULL;
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bdev = malloc(sizeof(struct bdev));
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if (!bdev)
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return NULL;
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memset(bdev, 0, sizeof(struct bdev));
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bdev->ops = bdevs[i].ops;
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bdev->type = bdevs[i].name;
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return bdev;
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}
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static const struct bdev_type *bdev_query(const char *src)
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{
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int i;
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for (i=0; i<numbdevs; i++) {
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int r;
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r = bdevs[i].ops->detect(src);
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if (r)
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break;
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}
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if (i == numbdevs)
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return NULL;
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return &bdevs[i];
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}
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struct bdev *bdev_init(struct lxc_conf *conf, const char *src, const char *dst,
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const char *mntopts)
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{
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struct bdev *bdev;
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const struct bdev_type *q;
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|
||||||
if (!src)
|
|
||||||
src = conf->rootfs.path;
|
|
||||||
|
|
||||||
if (!src)
|
|
||||||
return NULL;
|
|
||||||
|
|
||||||
q = bdev_query(src);
|
|
||||||
if (!q)
|
|
||||||
return NULL;
|
|
||||||
|
|
||||||
bdev = malloc(sizeof(struct bdev));
|
|
||||||
if (!bdev)
|
|
||||||
return NULL;
|
|
||||||
memset(bdev, 0, sizeof(struct bdev));
|
|
||||||
bdev->ops = q->ops;
|
|
||||||
bdev->type = q->name;
|
|
||||||
if (mntopts)
|
|
||||||
bdev->mntopts = strdup(mntopts);
|
|
||||||
if (src)
|
|
||||||
bdev->src = strdup(src);
|
|
||||||
if (dst)
|
|
||||||
bdev->dest = strdup(dst);
|
|
||||||
if (strcmp(bdev->type, "nbd") == 0)
|
|
||||||
bdev->nbd_idx = conf->nbd_idx;
|
|
||||||
|
|
||||||
return bdev;
|
|
||||||
}
|
|
||||||
|
|
||||||
bool bdev_is_dir(struct lxc_conf *conf, const char *path)
|
|
||||||
{
|
|
||||||
struct bdev *orig = bdev_init(conf, path, NULL, NULL);
|
|
||||||
bool ret = false;
|
|
||||||
if (!orig)
|
|
||||||
return ret;
|
|
||||||
if (strcmp(orig->type, "dir") == 0)
|
|
||||||
ret = true;
|
|
||||||
bdev_put(orig);
|
|
||||||
return ret;
|
|
||||||
}
|
}
|
||||||
|
|
||||||
bool bdev_can_backup(struct lxc_conf *conf)
|
bool bdev_can_backup(struct lxc_conf *conf)
|
||||||
@ -620,36 +296,6 @@ bool bdev_can_backup(struct lxc_conf *conf)
|
|||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
|
||||||
* is an unprivileged user allowed to make this kind of snapshot
|
|
||||||
*/
|
|
||||||
static bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
|
|
||||||
bool maybesnap)
|
|
||||||
{
|
|
||||||
if (!t) {
|
|
||||||
// new type will be same as original
|
|
||||||
// (unless snap && b->type == dir, in which case it will be
|
|
||||||
// overlayfs -- which is also allowed)
|
|
||||||
if (strcmp(b->type, "dir") == 0 ||
|
|
||||||
strcmp(b->type, "aufs") == 0 ||
|
|
||||||
strcmp(b->type, "overlayfs") == 0 ||
|
|
||||||
strcmp(b->type, "btrfs") == 0 ||
|
|
||||||
strcmp(b->type, "loop") == 0)
|
|
||||||
return true;
|
|
||||||
return false;
|
|
||||||
}
|
|
||||||
|
|
||||||
// unprivileged users can copy and snapshot dir, overlayfs,
|
|
||||||
// and loop. In particular, not zfs, btrfs, or lvm.
|
|
||||||
if (strcmp(t, "dir") == 0 ||
|
|
||||||
strcmp(t, "aufs") == 0 ||
|
|
||||||
strcmp(t, "overlayfs") == 0 ||
|
|
||||||
strcmp(t, "btrfs") == 0 ||
|
|
||||||
strcmp(t, "loop") == 0)
|
|
||||||
return true;
|
|
||||||
return false;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* If we're not snaphotting, then bdev_copy becomes a simple case of mount
|
* If we're not snaphotting, then bdev_copy becomes a simple case of mount
|
||||||
* the original, mount the new, and rsync the contents.
|
* the original, mount the new, and rsync the contents.
|
||||||
@ -697,7 +343,7 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
|
|||||||
return NULL;
|
return NULL;
|
||||||
}
|
}
|
||||||
ret = snprintf(orig->dest, len, "%s/%s/rootfs", oldpath, oldname);
|
ret = snprintf(orig->dest, len, "%s/%s/rootfs", oldpath, oldname);
|
||||||
if (ret < 0 || ret >= len) {
|
if (ret < 0 || (size_t)ret >= len) {
|
||||||
ERROR("rootfs path too long");
|
ERROR("rootfs path too long");
|
||||||
bdev_put(orig);
|
bdev_put(orig);
|
||||||
return NULL;
|
return NULL;
|
||||||
@ -811,23 +457,6 @@ err:
|
|||||||
return NULL;
|
return NULL;
|
||||||
}
|
}
|
||||||
|
|
||||||
static struct bdev *do_bdev_create(const char *dest, const char *type,
|
|
||||||
const char *cname, struct bdev_specs *specs)
|
|
||||||
{
|
|
||||||
|
|
||||||
struct bdev *bdev = bdev_get(type);
|
|
||||||
if (!bdev) {
|
|
||||||
return NULL;
|
|
||||||
}
|
|
||||||
|
|
||||||
if (bdev->ops->create(bdev, dest, cname, specs) < 0) {
|
|
||||||
bdev_put(bdev);
|
|
||||||
return NULL;
|
|
||||||
}
|
|
||||||
|
|
||||||
return bdev;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* bdev_create:
|
* bdev_create:
|
||||||
* Create a backing store for a container.
|
* Create a backing store for a container.
|
||||||
@ -852,7 +481,7 @@ struct bdev *bdev_create(const char *dest, const char *type, const char *cname,
|
|||||||
int i;
|
int i;
|
||||||
// try for the best backing store type, according to our
|
// try for the best backing store type, according to our
|
||||||
// opinionated preferences
|
// opinionated preferences
|
||||||
for (i=0; best_options[i]; i++) {
|
for (i = 0; best_options[i]; i++) {
|
||||||
if ((bdev = do_bdev_create(dest, best_options[i], cname, specs)))
|
if ((bdev = do_bdev_create(dest, best_options[i], cname, specs)))
|
||||||
return bdev;
|
return bdev;
|
||||||
}
|
}
|
||||||
@ -861,7 +490,7 @@ struct bdev *bdev_create(const char *dest, const char *type, const char *cname,
|
|||||||
|
|
||||||
// -B lvm,dir
|
// -B lvm,dir
|
||||||
if (strchr(type, ',') != NULL) {
|
if (strchr(type, ',') != NULL) {
|
||||||
char *dup = alloca(strlen(type)+1), *saveptr = NULL, *token;
|
char *dup = alloca(strlen(type) + 1), *saveptr = NULL, *token;
|
||||||
strcpy(dup, type);
|
strcpy(dup, type);
|
||||||
for (token = strtok_r(dup, ",", &saveptr); token;
|
for (token = strtok_r(dup, ",", &saveptr); token;
|
||||||
token = strtok_r(NULL, ",", &saveptr)) {
|
token = strtok_r(NULL, ",", &saveptr)) {
|
||||||
@ -873,29 +502,6 @@ struct bdev *bdev_create(const char *dest, const char *type, const char *cname,
|
|||||||
return do_bdev_create(dest, type, cname, specs);
|
return do_bdev_create(dest, type, cname, specs);
|
||||||
}
|
}
|
||||||
|
|
||||||
bool rootfs_is_blockdev(struct lxc_conf *conf)
|
|
||||||
{
|
|
||||||
const struct bdev_type *q;
|
|
||||||
struct stat st;
|
|
||||||
int ret;
|
|
||||||
|
|
||||||
if (!conf->rootfs.path || strcmp(conf->rootfs.path, "/") == 0 ||
|
|
||||||
strlen(conf->rootfs.path) == 0)
|
|
||||||
return false;
|
|
||||||
|
|
||||||
ret = stat(conf->rootfs.path, &st);
|
|
||||||
if (ret == 0 && S_ISBLK(st.st_mode))
|
|
||||||
return true;
|
|
||||||
q = bdev_query(conf->rootfs.path);
|
|
||||||
if (!q)
|
|
||||||
return false;
|
|
||||||
if (strcmp(q->name, "lvm") == 0 ||
|
|
||||||
strcmp(q->name, "loop") == 0 ||
|
|
||||||
strcmp(q->name, "nbd") == 0)
|
|
||||||
return true;
|
|
||||||
return false;
|
|
||||||
}
|
|
||||||
|
|
||||||
bool bdev_destroy(struct lxc_conf *conf)
|
bool bdev_destroy(struct lxc_conf *conf)
|
||||||
{
|
{
|
||||||
struct bdev *r;
|
struct bdev *r;
|
||||||
@ -932,28 +538,78 @@ int bdev_destroy_wrapper(void *data)
|
|||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
struct bdev *bdev_init(struct lxc_conf *conf, const char *src, const char *dst,
|
||||||
* attach_block_device returns true if all went well,
|
const char *mntopts)
|
||||||
* meaning either a block device was attached or was not
|
|
||||||
* needed. It returns false if something went wrong and
|
|
||||||
* container startup should be stopped.
|
|
||||||
*/
|
|
||||||
bool attach_block_device(struct lxc_conf *conf)
|
|
||||||
{
|
{
|
||||||
char *path;
|
struct bdev *bdev;
|
||||||
|
const struct bdev_type *q;
|
||||||
|
|
||||||
if (!conf->rootfs.path)
|
if (!src)
|
||||||
return true;
|
src = conf->rootfs.path;
|
||||||
path = conf->rootfs.path;
|
|
||||||
if (!requires_nbd(path))
|
if (!src)
|
||||||
return true;
|
return NULL;
|
||||||
path = strchr(path, ':');
|
|
||||||
if (!path)
|
q = bdev_query(src);
|
||||||
return false;
|
if (!q)
|
||||||
path++;
|
return NULL;
|
||||||
if (!attach_nbd(path, conf))
|
|
||||||
return false;
|
bdev = malloc(sizeof(struct bdev));
|
||||||
return true;
|
if (!bdev)
|
||||||
|
return NULL;
|
||||||
|
memset(bdev, 0, sizeof(struct bdev));
|
||||||
|
bdev->ops = q->ops;
|
||||||
|
bdev->type = q->name;
|
||||||
|
if (mntopts)
|
||||||
|
bdev->mntopts = strdup(mntopts);
|
||||||
|
if (src)
|
||||||
|
bdev->src = strdup(src);
|
||||||
|
if (dst)
|
||||||
|
bdev->dest = strdup(dst);
|
||||||
|
if (strcmp(bdev->type, "nbd") == 0)
|
||||||
|
bdev->nbd_idx = conf->nbd_idx;
|
||||||
|
|
||||||
|
return bdev;
|
||||||
|
}
|
||||||
|
|
||||||
|
bool bdev_is_dir(struct lxc_conf *conf, const char *path)
|
||||||
|
{
|
||||||
|
struct bdev *orig = bdev_init(conf, path, NULL, NULL);
|
||||||
|
bool ret = false;
|
||||||
|
if (!orig)
|
||||||
|
return ret;
|
||||||
|
if (strcmp(orig->type, "dir") == 0)
|
||||||
|
ret = true;
|
||||||
|
bdev_put(orig);
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
void bdev_put(struct bdev *bdev)
|
||||||
|
{
|
||||||
|
free(bdev->mntopts);
|
||||||
|
free(bdev->src);
|
||||||
|
free(bdev->dest);
|
||||||
|
free(bdev);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* return block size of dev->src in units of bytes
|
||||||
|
*/
|
||||||
|
int blk_getsize(struct bdev *bdev, uint64_t *size)
|
||||||
|
{
|
||||||
|
int fd, ret;
|
||||||
|
char *path = bdev->src;
|
||||||
|
|
||||||
|
if (strcmp(bdev->type, "loop") == 0)
|
||||||
|
path = bdev->src + 5;
|
||||||
|
|
||||||
|
fd = open(path, O_RDONLY);
|
||||||
|
if (fd < 0)
|
||||||
|
return -1;
|
||||||
|
|
||||||
|
ret = ioctl(fd, BLKGETSIZE64, size); // size of device in bytes
|
||||||
|
close(fd);
|
||||||
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
||||||
void detach_block_device(struct lxc_conf *conf)
|
void detach_block_device(struct lxc_conf *conf)
|
||||||
@ -961,3 +617,348 @@ void detach_block_device(struct lxc_conf *conf)
|
|||||||
if (conf->nbd_idx != -1)
|
if (conf->nbd_idx != -1)
|
||||||
detach_nbd_idx(conf->nbd_idx);
|
detach_nbd_idx(conf->nbd_idx);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Given a bdev (presumably blockdev-based), detect the fstype
|
||||||
|
* by trying mounting (in a private mntns) it.
|
||||||
|
* @bdev: bdev to investigate
|
||||||
|
* @type: preallocated char* in which to write the fstype
|
||||||
|
* @len: length of passed in char*
|
||||||
|
* Returns length of fstype, of -1 on error
|
||||||
|
*/
|
||||||
|
int detect_fs(struct bdev *bdev, char *type, int len)
|
||||||
|
{
|
||||||
|
int p[2], ret;
|
||||||
|
size_t linelen;
|
||||||
|
pid_t pid;
|
||||||
|
FILE *f;
|
||||||
|
char *sp1, *sp2, *sp3, *line = NULL;
|
||||||
|
char *srcdev;
|
||||||
|
|
||||||
|
if (!bdev || !bdev->src || !bdev->dest)
|
||||||
|
return -1;
|
||||||
|
|
||||||
|
srcdev = bdev->src;
|
||||||
|
if (strcmp(bdev->type, "loop") == 0)
|
||||||
|
srcdev = bdev->src + 5;
|
||||||
|
|
||||||
|
ret = pipe(p);
|
||||||
|
if (ret < 0)
|
||||||
|
return -1;
|
||||||
|
if ((pid = fork()) < 0)
|
||||||
|
return -1;
|
||||||
|
if (pid > 0) {
|
||||||
|
int status;
|
||||||
|
close(p[1]);
|
||||||
|
memset(type, 0, len);
|
||||||
|
ret = read(p[0], type, len - 1);
|
||||||
|
close(p[0]);
|
||||||
|
if (ret < 0) {
|
||||||
|
SYSERROR("error reading from pipe");
|
||||||
|
wait(&status);
|
||||||
|
return -1;
|
||||||
|
} else if (ret == 0) {
|
||||||
|
ERROR("child exited early - fstype not found");
|
||||||
|
wait(&status);
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
wait(&status);
|
||||||
|
type[len - 1] = '\0';
|
||||||
|
INFO("detected fstype %s for %s", type, srcdev);
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (unshare(CLONE_NEWNS) < 0)
|
||||||
|
exit(1);
|
||||||
|
|
||||||
|
if (detect_shared_rootfs()) {
|
||||||
|
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL)) {
|
||||||
|
SYSERROR("Failed to make / rslave");
|
||||||
|
ERROR("Continuing...");
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = mount_unknown_fs(srcdev, bdev->dest, bdev->mntopts);
|
||||||
|
if (ret < 0) {
|
||||||
|
ERROR("failed mounting %s onto %s to detect fstype", srcdev, bdev->dest);
|
||||||
|
exit(1);
|
||||||
|
}
|
||||||
|
// if symlink, get the real dev name
|
||||||
|
char devpath[MAXPATHLEN];
|
||||||
|
char *l = linkderef(srcdev, devpath);
|
||||||
|
if (!l)
|
||||||
|
exit(1);
|
||||||
|
f = fopen("/proc/self/mounts", "r");
|
||||||
|
if (!f)
|
||||||
|
exit(1);
|
||||||
|
while (getline(&line, &linelen, f) != -1) {
|
||||||
|
sp1 = strchr(line, ' ');
|
||||||
|
if (!sp1)
|
||||||
|
exit(1);
|
||||||
|
*sp1 = '\0';
|
||||||
|
if (strcmp(line, l))
|
||||||
|
continue;
|
||||||
|
sp2 = strchr(sp1 + 1, ' ');
|
||||||
|
if (!sp2)
|
||||||
|
exit(1);
|
||||||
|
*sp2 = '\0';
|
||||||
|
sp3 = strchr(sp2 + 1, ' ');
|
||||||
|
if (!sp3)
|
||||||
|
exit(1);
|
||||||
|
*sp3 = '\0';
|
||||||
|
sp2++;
|
||||||
|
if (write(p[1], sp2, strlen(sp2)) != strlen(sp2))
|
||||||
|
exit(1);
|
||||||
|
exit(0);
|
||||||
|
}
|
||||||
|
exit(1);
|
||||||
|
}
|
||||||
|
|
||||||
|
int do_mkfs(const char *path, const char *fstype)
|
||||||
|
{
|
||||||
|
pid_t pid;
|
||||||
|
|
||||||
|
if ((pid = fork()) < 0) {
|
||||||
|
ERROR("error forking");
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
if (pid > 0)
|
||||||
|
return wait_for_pid(pid);
|
||||||
|
|
||||||
|
// If the file is not a block device, we don't want mkfs to ask
|
||||||
|
// us about whether to proceed.
|
||||||
|
if (null_stdfds() < 0)
|
||||||
|
exit(1);
|
||||||
|
execlp("mkfs", "mkfs", "-t", fstype, path, NULL);
|
||||||
|
exit(1);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* This will return 1 for physical disks, qemu-nbd, loop, etc right now only lvm
|
||||||
|
* is a block device.
|
||||||
|
*/
|
||||||
|
int is_blktype(struct bdev *b)
|
||||||
|
{
|
||||||
|
if (strcmp(b->type, "lvm") == 0)
|
||||||
|
return 1;
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
int mount_unknown_fs(const char *rootfs, const char *target,
|
||||||
|
const char *options)
|
||||||
|
{
|
||||||
|
struct cbarg {
|
||||||
|
const char *rootfs;
|
||||||
|
const char *target;
|
||||||
|
const char *options;
|
||||||
|
} cbarg = {
|
||||||
|
.rootfs = rootfs,
|
||||||
|
.target = target,
|
||||||
|
.options = options,
|
||||||
|
};
|
||||||
|
|
||||||
|
/*
|
||||||
|
* find the filesystem type with brute force:
|
||||||
|
* first we check with /etc/filesystems, in case the modules
|
||||||
|
* are auto-loaded and fall back to the supported kernel fs
|
||||||
|
*/
|
||||||
|
char *fsfile[] = {
|
||||||
|
"/etc/filesystems",
|
||||||
|
"/proc/filesystems",
|
||||||
|
};
|
||||||
|
|
||||||
|
size_t i;
|
||||||
|
for (i = 0; i < sizeof(fsfile) / sizeof(fsfile[0]); i++) {
|
||||||
|
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
if (access(fsfile[i], F_OK))
|
||||||
|
continue;
|
||||||
|
|
||||||
|
ret = lxc_file_for_each_line(fsfile[i], find_fstype_cb, &cbarg);
|
||||||
|
if (ret < 0) {
|
||||||
|
ERROR("failed to parse '%s'", fsfile[i]);
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (ret)
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
ERROR("failed to determine fs type for '%s'", rootfs);
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
|
||||||
|
bool rootfs_is_blockdev(struct lxc_conf *conf)
|
||||||
|
{
|
||||||
|
const struct bdev_type *q;
|
||||||
|
struct stat st;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
if (!conf->rootfs.path || strcmp(conf->rootfs.path, "/") == 0 ||
|
||||||
|
strlen(conf->rootfs.path) == 0)
|
||||||
|
return false;
|
||||||
|
|
||||||
|
ret = stat(conf->rootfs.path, &st);
|
||||||
|
if (ret == 0 && S_ISBLK(st.st_mode))
|
||||||
|
return true;
|
||||||
|
q = bdev_query(conf->rootfs.path);
|
||||||
|
if (!q)
|
||||||
|
return false;
|
||||||
|
if (strcmp(q->name, "lvm") == 0 ||
|
||||||
|
strcmp(q->name, "loop") == 0 ||
|
||||||
|
strcmp(q->name, "nbd") == 0)
|
||||||
|
return true;
|
||||||
|
return false;
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct bdev *do_bdev_create(const char *dest, const char *type,
|
||||||
|
const char *cname, struct bdev_specs *specs)
|
||||||
|
{
|
||||||
|
|
||||||
|
struct bdev *bdev = bdev_get(type);
|
||||||
|
if (!bdev) {
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (bdev->ops->create(bdev, dest, cname, specs) < 0) {
|
||||||
|
bdev_put(bdev);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
return bdev;
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct bdev *bdev_get(const char *type)
|
||||||
|
{
|
||||||
|
int i;
|
||||||
|
struct bdev *bdev;
|
||||||
|
|
||||||
|
for (i = 0; i < numbdevs; i++) {
|
||||||
|
if (strcmp(bdevs[i].name, type) == 0)
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
if (i == numbdevs)
|
||||||
|
return NULL;
|
||||||
|
bdev = malloc(sizeof(struct bdev));
|
||||||
|
if (!bdev)
|
||||||
|
return NULL;
|
||||||
|
memset(bdev, 0, sizeof(struct bdev));
|
||||||
|
bdev->ops = bdevs[i].ops;
|
||||||
|
bdev->type = bdevs[i].name;
|
||||||
|
return bdev;
|
||||||
|
}
|
||||||
|
|
||||||
|
static const struct bdev_type *bdev_query(const char *src)
|
||||||
|
{
|
||||||
|
int i;
|
||||||
|
for (i = 0; i < numbdevs; i++) {
|
||||||
|
int r;
|
||||||
|
r = bdevs[i].ops->detect(src);
|
||||||
|
if (r)
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (i == numbdevs)
|
||||||
|
return NULL;
|
||||||
|
return &bdevs[i];
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* These are copied from conf.c. However as conf.c will be moved to using
|
||||||
|
* the callback system, they can be pulled from there eventually, so we
|
||||||
|
* don't need to pollute utils.c with these low level functions
|
||||||
|
*/
|
||||||
|
static int find_fstype_cb(char* buffer, void *data)
|
||||||
|
{
|
||||||
|
struct cbarg {
|
||||||
|
const char *rootfs;
|
||||||
|
const char *target;
|
||||||
|
const char *options;
|
||||||
|
} *cbarg = data;
|
||||||
|
|
||||||
|
unsigned long mntflags;
|
||||||
|
char *mntdata;
|
||||||
|
char *fstype;
|
||||||
|
|
||||||
|
/* we don't try 'nodev' entries */
|
||||||
|
if (strstr(buffer, "nodev"))
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
fstype = buffer;
|
||||||
|
fstype += lxc_char_left_gc(fstype, strlen(fstype));
|
||||||
|
fstype[lxc_char_right_gc(fstype, strlen(fstype))] = '\0';
|
||||||
|
|
||||||
|
DEBUG("trying to mount '%s'->'%s' with fstype '%s'",
|
||||||
|
cbarg->rootfs, cbarg->target, fstype);
|
||||||
|
|
||||||
|
if (parse_mntopts(cbarg->options, &mntflags, &mntdata) < 0) {
|
||||||
|
free(mntdata);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (mount(cbarg->rootfs, cbarg->target, fstype, mntflags, mntdata)) {
|
||||||
|
DEBUG("mount failed with error: %s", strerror(errno));
|
||||||
|
free(mntdata);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
free(mntdata);
|
||||||
|
|
||||||
|
INFO("mounted '%s' on '%s', with fstype '%s'",
|
||||||
|
cbarg->rootfs, cbarg->target, fstype);
|
||||||
|
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
static char *linkderef(char *path, char *dest)
|
||||||
|
{
|
||||||
|
struct stat sbuf;
|
||||||
|
ssize_t ret;
|
||||||
|
|
||||||
|
ret = stat(path, &sbuf);
|
||||||
|
if (ret < 0)
|
||||||
|
return NULL;
|
||||||
|
if (!S_ISLNK(sbuf.st_mode))
|
||||||
|
return path;
|
||||||
|
ret = readlink(path, dest, MAXPATHLEN);
|
||||||
|
if (ret < 0) {
|
||||||
|
SYSERROR("error reading link %s", path);
|
||||||
|
return NULL;
|
||||||
|
} else if (ret >= MAXPATHLEN) {
|
||||||
|
ERROR("link in %s too long", path);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
dest[ret] = '\0';
|
||||||
|
return dest;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* is an unprivileged user allowed to make this kind of snapshot
|
||||||
|
*/
|
||||||
|
static bool unpriv_snap_allowed(struct bdev *b, const char *t, bool snap,
|
||||||
|
bool maybesnap)
|
||||||
|
{
|
||||||
|
if (!t) {
|
||||||
|
// new type will be same as original
|
||||||
|
// (unless snap && b->type == dir, in which case it will be
|
||||||
|
// overlayfs -- which is also allowed)
|
||||||
|
if (strcmp(b->type, "dir") == 0 ||
|
||||||
|
strcmp(b->type, "aufs") == 0 ||
|
||||||
|
strcmp(b->type, "overlayfs") == 0 ||
|
||||||
|
strcmp(b->type, "btrfs") == 0 ||
|
||||||
|
strcmp(b->type, "loop") == 0)
|
||||||
|
return true;
|
||||||
|
return false;
|
||||||
|
}
|
||||||
|
|
||||||
|
// unprivileged users can copy and snapshot dir, overlayfs,
|
||||||
|
// and loop. In particular, not zfs, btrfs, or lvm.
|
||||||
|
if (strcmp(t, "dir") == 0 ||
|
||||||
|
strcmp(t, "aufs") == 0 ||
|
||||||
|
strcmp(t, "overlayfs") == 0 ||
|
||||||
|
strcmp(t, "btrfs") == 0 ||
|
||||||
|
strcmp(t, "loop") == 0)
|
||||||
|
return true;
|
||||||
|
return false;
|
||||||
|
}
|
||||||
|
|||||||
Loading…
Reference in New Issue
Block a user