shaba/systemd-stable
1
1
Fork 0
mirror of https://github.com/systemd/systemd-stable.git synced 2024-12-24 21:34:08 +03:00
Code

Merge pull request #25570 from yuwata/dissect-rootless-image

Browse Source 
dissect: support to unmount image without root partition
This commit is contained in:
Lennart Poettering 2022-12-02 18:25:53 +01:00 committed by GitHub
commit f6484e8503
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 18 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/dissect/dissect.c
View File

@ -1176,9 +1176,9 @@ static int action_list_or_mtree_or_copy(DissectedImage *m, LoopDevice *d) {
static int action_umount(const char *path) {
_cleanup_close_ int fd = -1;
_cleanup_free_ char *canonical = NULL, *devname = NULL;
_cleanup_free_ char *canonical = NULL;
_cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
dev_t devno;
_cleanup_(sd_device_unrefp) sd_device *dev = NULL;
int r;
fd = chase_symlinks_and_open(path, NULL, 0, O_DIRECTORY, &canonical);
@ -1193,18 +1193,26 @@ static int action_umount(const char *path) {
if (r < 0)
return log_error_errno(r, "Failed to determine whether '%s' is a mount point: %m", canonical);
r = fd_get_whole_disk(fd, /*backing=*/ true, &devno);
r = block_device_new_from_fd(fd, BLOCK_DEVICE_LOOKUP_WHOLE_DISK | BLOCK_DEVICE_LOOKUP_BACKING, &dev);
if (r < 0) {
_cleanup_close_ int usr_fd = -1;
/* The command `systemd-dissect --mount` expects that the image at least has the root or /usr
* partition. If it does not have the root partition, then we mount the /usr partition on a
* tmpfs. Hence, let's try to find the backing block device through the /usr partition. */
usr_fd = openat(fd, "usr", O_CLOEXEC | O_DIRECTORY | O_NOFOLLOW);
if (usr_fd < 0)
return log_error_errno(errno, "Failed to open '%s/usr': %m", canonical);
r = block_device_new_from_fd(usr_fd, BLOCK_DEVICE_LOOKUP_WHOLE_DISK | BLOCK_DEVICE_LOOKUP_BACKING, &dev);
}
if (r < 0)
return log_error_errno(r, "Failed to find backing block device for '%s': %m", canonical);
r = devname_from_devnum(S_IFBLK, devno, &devname);
r = loop_device_open(dev, 0, LOCK_EX, &d);
if (r < 0)
return log_error_errno(r, "Failed to get devname of block device " DEVNUM_FORMAT_STR ": %m",
DEVNUM_FORMAT_VAL(devno));
r = loop_device_open_from_path(devname, 0, LOCK_EX, &d);
if (r < 0)
return log_error_errno(r, "Failed to open loop device '%s': %m", devname);
return log_device_error_errno(dev, r, "Failed to open loopback block device: %m");
/* We've locked the loop device, now we're ready to unmount. To allow the unmount to succeed, we have
* to close the O_PATH fd we opened earlier. */