[SOLVED] /var/run/media instead of /run/media after last update in 64-Current

gauchao · 07-23-2021, 12:41 PM

As the title says, in Slackware64-Current, after the last updates, I noticed that my removeable medias are being mounted under /var/run/media instead of /run/media.

I don't remember if there was a symlink before and I don't think I have changed any of these links manually.

Anybody else has noticed this?

Thank you!

marav · 07-23-2021, 12:47 PM

In /etc/rc.d/rc.S

Code:

# Bind mount /run to /var/run:
mount -o bind /run /var/run

Since

Code:

+--------------------------+
Thu Feb 13 20:17:58 UTC 2020
a/sysvinit-scripts-2.1-noarch-29.txz:  Rebuilt.
  rc.S: make /var/run a bind mount to /run. Thanks to Robby Workman

Small reminder, especially when using the -current:
It is always important and useful to read the changelog

gauchao · 07-23-2021, 01:05 PM

Yes, this is from 2020. I always watch the changelogs before applying any upgrade especially when "bumps" can occur but I didn´t remember this bind mount.

However, all my removeable units were being mounted as /run/media until yesterday. Today they were mounted as /var/run/media. This has made my automated backup scripts fail, but I can fix them.

bassmadrigal · 07-23-2021, 01:07 PM

Quote:

Originally Posted by gauchao

Yes, this is from 2020. I always watch the changelogs before applying any upgrade especially when "bumps" can occur but I didn´t remember this bind mount.

However, all my removeable units were being mounted as /run/media until yesterday. Today they were mounted as /var/run/media. This has made my automated backup scripts fail, but I can fix them.

The location it's mounted to shouldn't matter since it's a bind mount. It should show up in both.

Do you have /var/run as a bind mount to /run in your mount output?

marav · 07-23-2021, 01:24 PM

I think because of the "--make-shared" option in /etc/rc.d/rc.S

Code:

# If /run exists, mount a tmpfs on it (unless the
# initrd has already done so):
if [ -d /run ]; then
  if ! grep -wq "tmpfs /run tmpfs" /proc/mounts ; then
    /sbin/mount -v -n -t tmpfs tmpfs /run -o mode=0755,size=32M,nodev,nosuid,noexec
  fi
  # Make sure that mounts below /run are visible in both /run and /var/run:
  /sbin/mount --make-shared /run
fi

Code:

root:~/ # cat /proc/self/mountinfo | grep shared                                                                                                            [20:23:35]
26 28 0:25 / /run rw,nosuid,nodev,noexec,relatime shared:1 - tmpfs tmpfs rw,size=32768k,mode=755,inode64
46 28 0:25 / /var/run rw,nosuid,nodev,noexec,relatime shared:1 - tmpfs tmpfs rw,size=32768k,mode=755,inode64
51 26 0:46 / /run/user/1001 rw,nosuid,nodev,relatime shared:3 - tmpfs tmpfs rw,size=784832k,nr_inodes=196208,mode=700,uid=1001,gid=1001,inode64
52 46 0:46 / /var/run/user/1001 rw,nosuid,nodev,relatime shared:3 - tmpfs tmpfs rw,size=784832k,nr_inodes=196208,mode=700,uid=1001,gid=1001,inode64
481 51 0:70 / /run/user/1001/gvfs rw,nosuid,nodev,relatime shared:2 - fuse.gvfsd-fuse gvfsd-fuse rw,user_id=1001,group_id=1001
482 52 0:70 / /var/run/user/1001/gvfs rw,nosuid,nodev,relatime shared:2 - fuse.gvfsd-fuse gvfsd-fuse rw,user_id=1001,group_id=1001

LuckyCyborg · 07-23-2021, 01:31 PM

Quote:

Originally Posted by gauchao

As the title says, in Slackware64-Current, after the last updates, I noticed that my removeable medias are being mounted under /var/run/media instead of /run/media.

I don't remember if there was a symlink before and I don't think I have changed any of these links manually.

Anybody else has noticed this?

Thank you!

Yes, it was observed by many - specially when their Plasma5 desktop inexplicably crashes while mounting an USB drive.

The main cause is the Slackware invention of shared binding of /var/run to /run and until now nobody found an explanation for this and why it is useful, while other major distributions just do a symbolic link of /var/run to /run and looks like the various software expects this - we found at least one which did it: Solid-5.84 of Plasma5

IF you want to do the things like everyone else do, there's a small patch for /etc/rc.d/rc.S

Code:

--- rc.S.orig	2021-07-23 11:55:00.234023711 +0300
+++ rc.S	2021-07-23 19:44:55.665037452 +0300
@@ -22,9 +22,11 @@
 if [ -d /run ]; then
   if ! grep -wq "tmpfs /run tmpfs" /proc/mounts ; then
     /sbin/mount -v -n -t tmpfs tmpfs /run -o mode=0755,size=32M,nodev,nosuid,noexec
+  fi 
+  # Make sure that /var/run is a symbolic link pointing to /run:
+  if [ ! -L /var/run ]; then
+    (cd /var; rm -rf run; ln -sf ../run run)
   fi
-  # Make sure that mounts below /run are visible in both /run and /var/run:
-  /sbin/mount --make-shared /run
 fi
 
 # Load the loop device kernel module:
@@ -367,8 +369,6 @@
   /sbin/mount -a -v -t nonfs,nosmbfs,nocifs,noproc,nosysfs | grep successfully | cut -f 1 -d : | tr -d ' ' | while read dev ; do mount | grep " ${dev} " ; done
 fi
 
-# Bind mount /run to /var/run:
-mount -o bind /run /var/run
 
 # Enable swapping again.  This is needed in case a swapfile is used,
 # as it can't be enabled until the filesystem it resides on has been

On the next reboot, the /var/run will be update on the fly as being a symlink to /run and double mounting of your devices magically will disappear.

Also, you will need to apply this patch, or to rebuild the current Solid package with a patch which you can find into Plasma5 thread, if you use Plasma5 and you want to be sure that it does crash inexplicably.

gauchao · 07-23-2021, 01:46 PM

Exactly, the device is being "double" mounted under /var/run/media and /run/media, but I don't see anything in my mount output.

In Dolphin, the device shows a mount point under /var/run/media, whether in Thunar it is shown as /run/media.

From cli, I see both mount points coexist.

Quote:

I think because of the "--make-shared" option in /etc/rc.d/rc.S

I see this option and it now makes sense.

bassmadrigal · 07-23-2021, 01:48 PM

Am I misunderstanding bind mounts? I thought that both /var/run and /run will be mirrored. OP is not seeing this, which, to me, says it's not a bind mount. Am I mistaken in that?

LuckyCyborg · 07-23-2021, 01:51 PM

Quote:

Originally Posted by gauchao

Exactly, the device is being "double" mounted under /var/run/media and /run/media, but I don't see anything in my mount output.

In Dolphin, the device shows a mount point under /var/run/media, whether in Thunar it is shown as /run/media.

From cli, I see both mount points coexist.

That's mountpoint from /var/run/media exists and does not exists in the same time, because nobody and nothing mounted something there. In fact, the poor Dolphin mounted your device into /run/media .

I call this Schrodinger's Cat Mountpoint and it's specific to Slackware.

LuckyCyborg · 07-23-2021, 01:53 PM

Quote:

Originally Posted by bassmadrigal

Am I misunderstanding bind mounts? I thought that both /var/run and /run will be mirrored. OP is not seeing this, which, to me, says it's not a bind mount. Am I mistaken in that?

Welcome to Wonderful World of Shared Bind Mounting, which confuses both the users and the programs!

BTW, in the Plasma5 thread I explained that Solid (then Doplhin, Krusader, Konqueror, etc) may chose the mountpoint from /var/run/media instead of the one from /run/media even the application itself mounts the device on /run/media .

You know, I posted dumps from /proc/self/mountinfo of Slackware and openSUSE to explain WHY.

marav · 07-23-2021, 02:04 PM

Quote:

Originally Posted by bassmadrigal

Am I misunderstanding bind mounts? I thought that both /var/run and /run will be mirrored. OP is not seeing this, which, to me, says it's not a bind mount. Am I mistaken in that?

I too, until recently, thought that by doing mount you would see :
/dir1 /media/dir1 ....... (rw,.... ,bind)

gauchao · 07-23-2021, 02:16 PM

This is the tail of mount output. I don't see bind in it.

Quote:

/dev/sdc1 on /run/media/removeabledrive/SANDISK64 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)
/dev/sdc1 on /var/run/media/removeabledrive/SANDISK64 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro)

Maybe I am using wrong nomenclature about bind mount... sorry. However, inspecting from the command line, I see my removeabledrive is being mounted both under /var/run/media and /run/media, which I learned from Marav that comes from the "--make-shared" option in /etc/rc.d/rc.S. And Dolphin began to display the drive under /var/run/media today whereas yesterday it used to show the drive under /run/media. Both are the same.

LuckyCyborg · 07-23-2021, 02:16 PM

Quote:

Originally Posted by marav

I too, until recently, thought that by doing mount you would see :
/dir1 /media/dir1 ....... (rw,.... ,bind)

When two directory are mounted with "shared bind", when you mount a device on a subfolder of the first, a second folder and mountpoint will be automatically created on the second.

Technically, on today Slackware every time you mount something on /run that particular device is two times mounted. Secondly into /var/run - this was the root cause of the Plasma5 crashes which was discussed.

LuckyCyborg · 07-23-2021, 02:19 PM

Quote:

Originally Posted by gauchao

This is the tail of mount output. I don't see bind in it.

Maybe I am using wrong nomenclature about bind mount... sorry. However, inspecting from the command line, I see my removeabledrive is being mounted both under /var/run/media and /run/media, which I learned from Marav that comes from the "--make-shared" option in /etc/rc.d/rc.S. And Dolphin began to display the drive under /var/run/media today whereas yeaterday it used to show the drive under /run/media. Both are the same.

Long story short, IF you want to fix this double mounting of your pendrive, this is the way: make /var/run a symlink to /run like openSUSE, Ubuntu or Fedora do.

You will need to modify your /etc/rc.d/rc.S too.

igadoter · 07-23-2021, 02:27 PM

Just mount device and call df. df is using libmount in contrary to say cat. So parsing /proc/self/mountinfo with cat does not provide correct information about mounts.