0c69794138
These lines are generally out-of-date, incomplete and unnecessary. With SPDX and git repository much more accurate and fine grained information about licensing and authorship is available, hence let's drop the per-file copyright notice. Of course, removing copyright lines of others is problematic, hence this commit only removes my own lines and leaves all others untouched. It might be nicer if sooner or later those could go away too, making git the only and accurate source of authorship information.
148 lines
4 KiB
C
148 lines
4 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <linux/loop.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "fd-util.h"
|
|
#include "loop-util.h"
|
|
#include "stat-util.h"
|
|
|
|
int loop_device_make(int fd, int open_flags, LoopDevice **ret) {
|
|
const struct loop_info64 info = {
|
|
.lo_flags = LO_FLAGS_AUTOCLEAR|LO_FLAGS_PARTSCAN|(open_flags == O_RDONLY ? LO_FLAGS_READ_ONLY : 0),
|
|
};
|
|
|
|
_cleanup_close_ int control = -1, loop = -1;
|
|
_cleanup_free_ char *loopdev = NULL;
|
|
struct stat st;
|
|
LoopDevice *d;
|
|
int nr, r;
|
|
|
|
assert(fd >= 0);
|
|
assert(ret);
|
|
assert(IN_SET(open_flags, O_RDWR, O_RDONLY));
|
|
|
|
if (fstat(fd, &st) < 0)
|
|
return -errno;
|
|
|
|
if (S_ISBLK(st.st_mode)) {
|
|
int copy;
|
|
|
|
/* If this is already a block device, store a copy of the fd as it is */
|
|
|
|
copy = fcntl(fd, F_DUPFD_CLOEXEC, 3);
|
|
if (copy < 0)
|
|
return -errno;
|
|
|
|
d = new0(LoopDevice, 1);
|
|
if (!d)
|
|
return -ENOMEM;
|
|
|
|
*d = (LoopDevice) {
|
|
.fd = copy,
|
|
.nr = -1,
|
|
};
|
|
|
|
*ret = d;
|
|
|
|
return 0;
|
|
}
|
|
|
|
r = stat_verify_regular(&st);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
|
|
if (control < 0)
|
|
return -errno;
|
|
|
|
nr = ioctl(control, LOOP_CTL_GET_FREE);
|
|
if (nr < 0)
|
|
return -errno;
|
|
|
|
if (asprintf(&loopdev, "/dev/loop%i", nr) < 0)
|
|
return -ENOMEM;
|
|
|
|
loop = open(loopdev, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|open_flags);
|
|
if (loop < 0)
|
|
return -errno;
|
|
|
|
if (ioctl(loop, LOOP_SET_FD, fd) < 0)
|
|
return -errno;
|
|
|
|
if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0)
|
|
return -errno;
|
|
|
|
d = new(LoopDevice, 1);
|
|
if (!d)
|
|
return -ENOMEM;
|
|
|
|
*d = (LoopDevice) {
|
|
.fd = TAKE_FD(loop),
|
|
.node = TAKE_PTR(loopdev),
|
|
.nr = nr,
|
|
};
|
|
|
|
*ret = d;
|
|
|
|
return (*ret)->fd;
|
|
}
|
|
|
|
int loop_device_make_by_path(const char *path, int open_flags, LoopDevice **ret) {
|
|
_cleanup_close_ int fd = -1;
|
|
|
|
assert(path);
|
|
assert(ret);
|
|
assert(IN_SET(open_flags, O_RDWR, O_RDONLY));
|
|
|
|
fd = open(path, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|open_flags);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
return loop_device_make(fd, open_flags, ret);
|
|
}
|
|
|
|
LoopDevice* loop_device_unref(LoopDevice *d) {
|
|
if (!d)
|
|
return NULL;
|
|
|
|
if (d->fd >= 0) {
|
|
|
|
if (d->nr >= 0 && !d->relinquished) {
|
|
if (ioctl(d->fd, LOOP_CLR_FD) < 0)
|
|
log_debug_errno(errno, "Failed to clear loop device: %m");
|
|
|
|
}
|
|
|
|
safe_close(d->fd);
|
|
}
|
|
|
|
if (d->nr >= 0 && !d->relinquished) {
|
|
_cleanup_close_ int control = -1;
|
|
|
|
control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
|
|
if (control < 0)
|
|
log_debug_errno(errno, "Failed to open loop control device: %m");
|
|
else {
|
|
if (ioctl(control, LOOP_CTL_REMOVE, d->nr) < 0)
|
|
log_debug_errno(errno, "Failed to remove loop device: %m");
|
|
}
|
|
}
|
|
|
|
free(d->node);
|
|
return mfree(d);
|
|
}
|
|
|
|
void loop_device_relinquish(LoopDevice *d) {
|
|
assert(d);
|
|
|
|
/* Don't attempt to clean up the loop device anymore from this point on. Leave the clean-ing up to the kernel
|
|
* itself, using the loop device "auto-clear" logic we already turned on when creating the device. */
|
|
|
|
d->relinquished = true;
|
|
}
|