#include <unistd.h>
#include "alloc-util.h"
+#include "errno-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "loop-util.h"
int loop_device_make_by_path(const char *path, int open_flags, uint32_t loop_flags, LoopDevice **ret) {
_cleanup_close_ int fd = -1;
+ int r;
assert(path);
assert(ret);
- assert(IN_SET(open_flags, O_RDWR, O_RDONLY));
+ assert(open_flags < 0 || IN_SET(open_flags, O_RDWR, O_RDONLY));
- fd = open(path, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|open_flags);
- if (fd < 0)
- return -errno;
+ /* Passing < 0 as open_flags here means we'll try to open the device writable if we can, retrying
+ * read-only if we cannot. */
+
+ fd = open(path, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|(open_flags >= 0 ? open_flags : O_RDWR));
+ if (fd < 0) {
+ r = -errno;
+
+ /* Retry read-only? */
+ if (open_flags >= 0 || !(ERRNO_IS_PRIVILEGE(r) || r == -EROFS))
+ return r;
+
+ fd = open(path, O_CLOEXEC|O_NONBLOCK|O_NOCTTY|O_RDONLY);
+ if (fd < 0)
+ return r; /* Propagate original error */
+
+ open_flags = O_RDONLY;
+ } else if (open_flags < 0)
+ open_flags = O_RDWR;
return loop_device_make(fd, open_flags, 0, 0, loop_flags, ret);
}
return NULL;
if (d->fd >= 0) {
+ /* Implicitly sync the device, since otherwise in-flight blocks might not get written */
+ if (fsync(d->fd) < 0)
+ log_debug_errno(errno, "Failed to sync loop block device, ignoring: %m");
+
if (d->nr >= 0 && !d->relinquished) {
if (ioctl(d->fd, LOOP_CLR_FD) < 0)
log_debug_errno(errno, "Failed to clear loop device: %m");
log_warning_errno(errno, "Failed to remove device %s: %m", strna(d->node));
break;
}
- usleep(50 * USEC_PER_MSEC);
+ (void) usleep(50 * USEC_PER_MSEC);
}
}