|
 |
f135e7 |
diff -Naur a/sys-utils/losetup.8 b/sys-utils/losetup.8
|
|
|
f135e7 |
--- a/sys-utils/losetup.8 2021-10-20 15:23:28.983136437 -0700
|
|
|
f135e7 |
+++ b/sys-utils/losetup.8 2021-10-20 15:23:54.314264432 -0700
|
|
|
f135e7 |
@@ -68,6 +68,13 @@
|
|
|
f135e7 |
file.
|
|
|
f135e7 |
.B This setup may be dangerous, can cause data loss, corruption and overwrites.
|
|
|
f135e7 |
Use \fB\-\-nooverlap\fR with \fB\-\-find\fR during setup to avoid this problem.
|
|
|
f135e7 |
+.sp
|
|
|
f135e7 |
+The loop device setup is not an atomic operation when used with \fB\-\-find\fP, and
|
|
|
f135e7 |
+.B losetup
|
|
|
f135e7 |
+does not protect this operation by any lock. The number of attempts is
|
|
|
f135e7 |
+internally restricted to a maximum of 16. It is recommended to use for example
|
|
|
f135e7 |
+.BR flock (1)
|
|
|
f135e7 |
+to avoid a collision in heavily parallel use cases.
|
|
|
f135e7 |
|
|
|
f135e7 |
.SH OPTIONS
|
|
|
f135e7 |
The \fIsize\fR and \fIoffset\fR
|
|
|
f135e7 |
@@ -170,6 +177,11 @@
|
|
|
f135e7 |
displays the status of a loop device, it returns 1 if the device
|
|
|
f135e7 |
is not configured and 2 if an error occurred which prevented
|
|
|
f135e7 |
determining the status of the device.
|
|
|
f135e7 |
+.SH NOTES
|
|
|
f135e7 |
+Since version 2.37
|
|
|
f135e7 |
+.B losetup
|
|
|
f135e7 |
+uses LOOP_CONFIGURE ioctl to setup a new loop device by one ioctl call. The
|
|
|
f135e7 |
+old versions use LOOP_SET_FD and LOOP_SET_STATUS64 ioctls to do the same.
|
|
|
f135e7 |
|
|
|
f135e7 |
.SH FILES
|
|
|
f135e7 |
.TP
|
|
|
f135e7 |
diff -Naur a/sys-utils/losetup.c b/sys-utils/losetup.c
|
|
|
f135e7 |
--- a/sys-utils/losetup.c 2021-10-20 15:23:28.902136028 -0700
|
|
|
f135e7 |
+++ b/sys-utils/losetup.c 2021-10-20 15:23:54.315264437 -0700
|
|
|
f135e7 |
@@ -463,7 +463,7 @@
|
|
|
f135e7 |
const char *file, uint64_t offset, uint64_t sizelimit)
|
|
|
f135e7 |
{
|
|
|
f135e7 |
int hasdev = loopcxt_has_device(lc);
|
|
|
f135e7 |
- int rc = 0;
|
|
|
f135e7 |
+ int rc = 0, ntries = 0;
|
|
|
f135e7 |
|
|
|
f135e7 |
/* losetup --find --noverlap file.img */
|
|
|
f135e7 |
if (!hasdev && nooverlap) {
|
|
|
f135e7 |
@@ -556,8 +556,12 @@
|
|
|
f135e7 |
rc = loopcxt_setup_device(lc);
|
|
|
f135e7 |
if (rc == 0)
|
|
|
f135e7 |
break; /* success */
|
|
|
f135e7 |
- if (errno == EBUSY && !hasdev)
|
|
|
f135e7 |
+
|
|
|
f135e7 |
+ if (errno == EBUSY && !hasdev && ntries < 16) {
|
|
|
f135e7 |
+ xusleep(200000);
|
|
|
f135e7 |
+ ntries++;
|
|
|
f135e7 |
continue;
|
|
|
f135e7 |
+ }
|
|
|
f135e7 |
|
|
|
f135e7 |
/* errors */
|
|
|
f135e7 |
errpre = hasdev && loopcxt_get_fd(lc) < 0 ?
|