Re: [OE-core] [RFC PATCH V2 0/5] Fix persistent tmp
Add Trevor who made the original commit: commit d5d40479d706cbb382850b9479c5dd9bfb801c99 Author: Trevor Woerner Date: Mon Feb 27 00:00:40 2023 VOLATILE_TMP_DIR: add Provide a mechanism to allow users to choose whether the /tmp directory is on persistent storage (non-volatile) or a RAM-based tmpfs (volatile). The default is volatile. Works for both sysvinit-based and systemd-based systems. and Ross who said he'd take a look at this RFC. On 2024-02-03 9:58 p.m., Changqing Li via lists.openembedded.org wrote: ping On 12/11/23 08:58, Changqing Li wrote: From: Changqing Li Hi, All Currently, VOLATILE_TMP_DIR not works, set VOLATILE_TMP_DIR="no", VOLATILE_LOG_DIR="no", after boot target, /var/tmp still link to tmpfs /var/volatile/tmp lrwxrwxrwx 1 root root 11 Mar 9 2018 lock -> ../run/lock drwxr-xr-x 4 root root 1024 Dec 4 07:55 log lrwxrwxrwx 1 root root 6 Mar 9 2018 run -> ../run drwxr-xr-x 3 root root 1024 Mar 9 2018 spool lrwxrwxrwx 1 root root 12 Mar 9 2018 tmp -> volatile/tmp drwxrwxrwt 4 root root 80 Dec 4 07:55 volatile So I do some research, fix this issue and do some other changes accordingly. Please help to review this patch, thanks. Targets: 1. Support persistent tmp, For persistent tmp, only /var/tmp is persistent, /tmp is tmpfs, For volatile tmp, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp 2. make systemd and SysVinit have the same directory structure. Currently, systemd and SysVinit have different directory structure, the difference focus on how to handle /tmp. when volatile is enabled, for sysVinit, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp refer [4][5]. but for systemd, /tmp is a directory, it is mounted by systemd as tmpfs. /var/tmp linked to /var/volatile/tmp. And for systemd, refer [6], set different age for /tmp and /var/tmp. I find that structured text helps me understand things, so here's a structured version of the sentences above: Currently, systemd and SysVinit have different directory structure; the difference focus on how to handle /tmp. When volatile is enabled, for sysVinit: /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp refer [4][5] but for systemd: /tmp is a directory, it is mounted by systemd as tmpfs. /var/tmp linked to /var/volatile/tmp and for systemd, refer [6], set different age for /tmp and /var/tmp. Since volatile disabled not works, ignore the difference when volatile is disabled. With this patch, VOLATILE_TMP_DIR will behavior like this: For both sysvinit and systemd: 1. VOLATILE_TMP_DIR="yes": /tmp link to /var/tmp, /var/tmp link to /var/volatile/log, /var/volatile is mounted as tmpfs In this case, for systemd, /tmp and /var/tmp will set to the same age, 10d. Compare to current behavior, there are 2 changes: 1) for systemd, /tmp changed from a directy to a symlink to /var/tmp 2) age of /tmp and /var/tmp will be same Okay but is an identical timestamp absolutely required or are you just trying to make things consistent to reduce the chance that a different timestamp could cause problems? I may have missed an explanation of why you want the 10d old timestamp anyway, that seems like a separate change that should follow-up the re-org changes. 2. VOLATILE_TMP_DIR="no": /tmp is a directory mounted as tmpfs, /var/tmp is a directory on persistent fs, and keep the age as [6] Change like this in order to meet [1][2], also maybe [3] for systemd. Compare to current behavior, there is one change: 1) for sysVinit, /tmp changed from a symlink to a directory You've carefully explained things but it does seem a bit complicated when you first read the explaination. It may have been better to start your explaination with the last statement you made, by saying something like this: This is going to be a detailed, lengthy explaination but the only change in runtime will be for sysVinit where /tmp is changed from a symlink to a directory to make it persistent. Ross, Trevor, Any comments or concerns ? Changqing is no one replies today, please just rebase and repost your full RFC patch to try to restart the discussion. Thanks, ../Randy [1] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s18.html [2] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s15.html [3] https://systemd.io/TEMPORARY_DIRECTORIES/ [4] https://git.openembedded.org/openembedded/tree/docs/usermanual/chapters/recipes.xml#n3535 [5] https://git.openembedded.org/openembedded-core/commit/?id=12c4acd7ac5a27cf3676065b60f1c8395c96854c [6] https://github.com/systemd/systemd/blob/main/tmpfiles.d/tmp.conf [7] https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html Test Result of following cases: 1. SysVinit VOLATILE_TMP_DIR="yes" VOLATILE_LOG_DIR="yes" root@qemux86-64:~# ls -al /tmp lrwxrwxrwx 1 root root 8 Dec 8 08:51 /tmp -> /var/tmp
Re: [OE-core] [RFC PATCH V2 0/5] Fix persistent tmp
Hi, Richard I had send a similar patch before, subjected as "bitbake.conf: support persistent /var/tmp", and you have replied me with some concerns on 2021/9/13. But I noticed that another variable VOLATILE_TMP_DIR is added in 2023. but as I tested, it not works, so I make this patch to make it work for both sysV and systemd. Not sure if you still have those concerns now, so just kindly ping to check. Thanks Changqing On 12/11/23 08:58, Changqing Li wrote: From: Changqing Li Hi, All Currently, VOLATILE_TMP_DIR not works, set VOLATILE_TMP_DIR="no", VOLATILE_LOG_DIR="no", after boot target, /var/tmp still link to tmpfs /var/volatile/tmp lrwxrwxrwx 1 root root 11 Mar 9 2018 lock -> ../run/lock drwxr-xr-x 4 root root 1024 Dec 4 07:55 log lrwxrwxrwx 1 root root6 Mar 9 2018 run -> ../run drwxr-xr-x 3 root root 1024 Mar 9 2018 spool lrwxrwxrwx 1 root root 12 Mar 9 2018 tmp -> volatile/tmp drwxrwxrwt 4 root root 80 Dec 4 07:55 volatile So I do some research, fix this issue and do some other changes accordingly. Please help to review this patch, thanks. Targets: 1. Support persistent tmp, For persistent tmp, only /var/tmp is persistent, /tmp is tmpfs, For volatile tmp, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp 2. make systemd and SysVinit have the same directory structure. Currently, systemd and SysVinit have different directory structure, the difference focus on how to handle /tmp. when volatile is enabled, for sysVinit, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp refer [4][5]. but for systemd, /tmp is a directory, it is mounted by systemd as tmpfs. /var/tmp linked to /var/volatile/tmp. And for systemd, refer [6], set different age for /tmp and /var/tmp. Since volatile disabled not works, ignore the difference when volatile is disabled. With this patch, VOLATILE_TMP_DIR will behavior like this: For both sysvinit and systemd: 1. VOLATILE_TMP_DIR="yes": /tmp link to /var/tmp, /var/tmp link to /var/volatile/log, /var/volatile is mounted as tmpfs In this case, for systemd, /tmp and /var/tmp will set to the same age, 10d. Compare to current behavior, there are 2 changes: 1) for systemd, /tmp changed from a directy to a symlink to /var/tmp 2) age of /tmp and /var/tmp will be same 2. VOLATILE_TMP_DIR="no": /tmp is a directory mounted as tmpfs, /var/tmp is a directory on persistent fs, and keep the age as [6] Change like this in order to meet [1][2], also maybe [3] for systemd. Compare to current behavior, there is one change: 1) for sysVinit, /tmp changed from a symlink to a directory [1]https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s18.html [2]https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s15.html [3]https://systemd.io/TEMPORARY_DIRECTORIES/ [4]https://git.openembedded.org/openembedded/tree/docs/usermanual/chapters/recipes.xml#n3535 [5]https://git.openembedded.org/openembedded-core/commit/?id=12c4acd7ac5a27cf3676065b60f1c8395c96854c [6]https://github.com/systemd/systemd/blob/main/tmpfiles.d/tmp.conf [7]https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html Test Result of following cases: 1. SysVinit VOLATILE_TMP_DIR="yes" VOLATILE_LOG_DIR="yes" root@qemux86-64:~# ls -al /tmp lrwxrwxrwx1 root root 8 Dec 8 08:51 /tmp -> /var/tmp root@qemux86-64:~# ls -al /var/log lrwxrwxrwx1 root root17 Dec 8 08:51 /var/log -> /var/volatile/log root@qemux86-64:~# ls -al /var/tmp lrwxrwxrwx1 root root17 Dec 8 08:51 /var/tmp -> /var/volatile/tmp root@qemux86-64:~# mount | grep volatile tmpfs on /var/volatile type tmpfs (rw,relatime) root@qemux86-64:~# 2. SysVinit VOLATILE_TMP_DIR="no" VOLATILE_LOG_DIR="no" root@qemux86-64:/# ls -al drwxr-xr-x 18 root root 1024 Dec 8 09:22 . drwxr-xr-x 18 root root 1024 Dec 8 09:22 .. drwxr-xr-x2 root root 3072 Mar 9 2018 bin drwxr-xr-x2 root root 1024 Mar 9 2018 boot drwxr-xr-x 13 root root 2960 Dec 8 09:24 dev drwxr-xr-x 20 root root 1024 Dec 8 09:24 etc drwxr-xr-x3 root root 1024 Mar 9 2018 home drwxr-xr-x6 root root 1024 Mar 9 2018 lib drwx--2 root root 12288 Dec 8 09:22 lost+found drwxr-xr-x2 root root 1024 Mar 9 2018 media drwxr-xr-x2 root root 1024 Mar 9 2018 mnt dr-xr-xr-x 161 root root 0 Dec 8 09:24 proc drwxr-xr-x4 root root 240 Dec 8 09:24 run drwxr-xr-x2 root root 3072 Mar 9 2018 sbin dr-xr-xr-x 12 root root 0 Dec 8 09:24 sys drwxrwxrwt2 root root40 Dec 8 09:24 tmp drwxr-xr-x9 root root 1024 Mar 9 2018 usr drwxr-xr-x 10 root root 1024 Dec 8 09:24 var root@qemux86-64:/# cd /var/ root@qemux86-64:/var# ls -al drwxr-xr-x 10 root root 1024 Dec 8
Re: [OE-core] [RFC PATCH V2 0/5] Fix persistent tmp
kindly ping On 12/11/23 08:58, Changqing Li wrote: From: Changqing Li Hi, All Currently, VOLATILE_TMP_DIR not works, set VOLATILE_TMP_DIR="no", VOLATILE_LOG_DIR="no", after boot target, /var/tmp still link to tmpfs /var/volatile/tmp lrwxrwxrwx 1 root root 11 Mar 9 2018 lock -> ../run/lock drwxr-xr-x 4 root root 1024 Dec 4 07:55 log lrwxrwxrwx 1 root root6 Mar 9 2018 run -> ../run drwxr-xr-x 3 root root 1024 Mar 9 2018 spool lrwxrwxrwx 1 root root 12 Mar 9 2018 tmp -> volatile/tmp drwxrwxrwt 4 root root 80 Dec 4 07:55 volatile So I do some research, fix this issue and do some other changes accordingly. Please help to review this patch, thanks. Targets: 1. Support persistent tmp, For persistent tmp, only /var/tmp is persistent, /tmp is tmpfs, For volatile tmp, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp 2. make systemd and SysVinit have the same directory structure. Currently, systemd and SysVinit have different directory structure, the difference focus on how to handle /tmp. when volatile is enabled, for sysVinit, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp refer [4][5]. but for systemd, /tmp is a directory, it is mounted by systemd as tmpfs. /var/tmp linked to /var/volatile/tmp. And for systemd, refer [6], set different age for /tmp and /var/tmp. Since volatile disabled not works, ignore the difference when volatile is disabled. With this patch, VOLATILE_TMP_DIR will behavior like this: For both sysvinit and systemd: 1. VOLATILE_TMP_DIR="yes": /tmp link to /var/tmp, /var/tmp link to /var/volatile/log, /var/volatile is mounted as tmpfs In this case, for systemd, /tmp and /var/tmp will set to the same age, 10d. Compare to current behavior, there are 2 changes: 1) for systemd, /tmp changed from a directy to a symlink to /var/tmp 2) age of /tmp and /var/tmp will be same 2. VOLATILE_TMP_DIR="no": /tmp is a directory mounted as tmpfs, /var/tmp is a directory on persistent fs, and keep the age as [6] Change like this in order to meet [1][2], also maybe [3] for systemd. Compare to current behavior, there is one change: 1) for sysVinit, /tmp changed from a symlink to a directory [1] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s18.html [2] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s15.html [3] https://systemd.io/TEMPORARY_DIRECTORIES/ [4] https://git.openembedded.org/openembedded/tree/docs/usermanual/chapters/recipes.xml#n3535 [5] https://git.openembedded.org/openembedded-core/commit/?id=12c4acd7ac5a27cf3676065b60f1c8395c96854c [6] https://github.com/systemd/systemd/blob/main/tmpfiles.d/tmp.conf [7] https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html Test Result of following cases: 1. SysVinit VOLATILE_TMP_DIR="yes" VOLATILE_LOG_DIR="yes" root@qemux86-64:~# ls -al /tmp lrwxrwxrwx1 root root 8 Dec 8 08:51 /tmp -> /var/tmp root@qemux86-64:~# ls -al /var/log lrwxrwxrwx1 root root17 Dec 8 08:51 /var/log -> /var/volatile/log root@qemux86-64:~# ls -al /var/tmp lrwxrwxrwx1 root root17 Dec 8 08:51 /var/tmp -> /var/volatile/tmp root@qemux86-64:~# mount | grep volatile tmpfs on /var/volatile type tmpfs (rw,relatime) root@qemux86-64:~# 2. SysVinit VOLATILE_TMP_DIR="no" VOLATILE_LOG_DIR="no" root@qemux86-64:/# ls -al drwxr-xr-x 18 root root 1024 Dec 8 09:22 . drwxr-xr-x 18 root root 1024 Dec 8 09:22 .. drwxr-xr-x2 root root 3072 Mar 9 2018 bin drwxr-xr-x2 root root 1024 Mar 9 2018 boot drwxr-xr-x 13 root root 2960 Dec 8 09:24 dev drwxr-xr-x 20 root root 1024 Dec 8 09:24 etc drwxr-xr-x3 root root 1024 Mar 9 2018 home drwxr-xr-x6 root root 1024 Mar 9 2018 lib drwx--2 root root 12288 Dec 8 09:22 lost+found drwxr-xr-x2 root root 1024 Mar 9 2018 media drwxr-xr-x2 root root 1024 Mar 9 2018 mnt dr-xr-xr-x 161 root root 0 Dec 8 09:24 proc drwxr-xr-x4 root root 240 Dec 8 09:24 run drwxr-xr-x2 root root 3072 Mar 9 2018 sbin dr-xr-xr-x 12 root root 0 Dec 8 09:24 sys drwxrwxrwt2 root root40 Dec 8 09:24 tmp drwxr-xr-x9 root root 1024 Mar 9 2018 usr drwxr-xr-x 10 root root 1024 Dec 8 09:24 var root@qemux86-64:/# cd /var/ root@qemux86-64:/var# ls -al drwxr-xr-x 10 root root 1024 Dec 8 09:24 . drwxr-xr-x 18 root root 1024 Dec 8 09:22 .. drwxr-xr-x2 root root 1024 Mar 9 2018 backups drwxr-xr-x2 root root 1024 Mar 9 2018 cache drwxr-xr-x4 root root 1024 Mar 9 2018 lib drwxr-xr-x2 root root 1024 Mar 9 2018 local lrwxrwxrwx1 root root 9 Dec 8 09:24 lock -> /run/lock drwxr-xr-x2 root
[OE-core] [RFC PATCH V2 0/5] Fix persistent tmp
From: Changqing Li Hi, All Currently, VOLATILE_TMP_DIR not works, set VOLATILE_TMP_DIR="no", VOLATILE_LOG_DIR="no", after boot target, /var/tmp still link to tmpfs /var/volatile/tmp lrwxrwxrwx 1 root root 11 Mar 9 2018 lock -> ../run/lock drwxr-xr-x 4 root root 1024 Dec 4 07:55 log lrwxrwxrwx 1 root root6 Mar 9 2018 run -> ../run drwxr-xr-x 3 root root 1024 Mar 9 2018 spool lrwxrwxrwx 1 root root 12 Mar 9 2018 tmp -> volatile/tmp drwxrwxrwt 4 root root 80 Dec 4 07:55 volatile So I do some research, fix this issue and do some other changes accordingly. Please help to review this patch, thanks. Targets: 1. Support persistent tmp, For persistent tmp, only /var/tmp is persistent, /tmp is tmpfs, For volatile tmp, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp 2. make systemd and SysVinit have the same directory structure. Currently, systemd and SysVinit have different directory structure, the difference focus on how to handle /tmp. when volatile is enabled, for sysVinit, /tmp link to /var/tmp, /var/tmp link to /var/volatile/tmp refer [4][5]. but for systemd, /tmp is a directory, it is mounted by systemd as tmpfs. /var/tmp linked to /var/volatile/tmp. And for systemd, refer [6], set different age for /tmp and /var/tmp. Since volatile disabled not works, ignore the difference when volatile is disabled. With this patch, VOLATILE_TMP_DIR will behavior like this: For both sysvinit and systemd: 1. VOLATILE_TMP_DIR="yes": /tmp link to /var/tmp, /var/tmp link to /var/volatile/log, /var/volatile is mounted as tmpfs In this case, for systemd, /tmp and /var/tmp will set to the same age, 10d. Compare to current behavior, there are 2 changes: 1) for systemd, /tmp changed from a directy to a symlink to /var/tmp 2) age of /tmp and /var/tmp will be same 2. VOLATILE_TMP_DIR="no": /tmp is a directory mounted as tmpfs, /var/tmp is a directory on persistent fs, and keep the age as [6] Change like this in order to meet [1][2], also maybe [3] for systemd. Compare to current behavior, there is one change: 1) for sysVinit, /tmp changed from a symlink to a directory [1] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s18.html [2] https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s15.html [3] https://systemd.io/TEMPORARY_DIRECTORIES/ [4] https://git.openembedded.org/openembedded/tree/docs/usermanual/chapters/recipes.xml#n3535 [5] https://git.openembedded.org/openembedded-core/commit/?id=12c4acd7ac5a27cf3676065b60f1c8395c96854c [6] https://github.com/systemd/systemd/blob/main/tmpfiles.d/tmp.conf [7] https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html Test Result of following cases: 1. SysVinit VOLATILE_TMP_DIR="yes" VOLATILE_LOG_DIR="yes" root@qemux86-64:~# ls -al /tmp lrwxrwxrwx1 root root 8 Dec 8 08:51 /tmp -> /var/tmp root@qemux86-64:~# ls -al /var/log lrwxrwxrwx1 root root17 Dec 8 08:51 /var/log -> /var/volatile/log root@qemux86-64:~# ls -al /var/tmp lrwxrwxrwx1 root root17 Dec 8 08:51 /var/tmp -> /var/volatile/tmp root@qemux86-64:~# mount | grep volatile tmpfs on /var/volatile type tmpfs (rw,relatime) root@qemux86-64:~# 2. SysVinit VOLATILE_TMP_DIR="no" VOLATILE_LOG_DIR="no" root@qemux86-64:/# ls -al drwxr-xr-x 18 root root 1024 Dec 8 09:22 . drwxr-xr-x 18 root root 1024 Dec 8 09:22 .. drwxr-xr-x2 root root 3072 Mar 9 2018 bin drwxr-xr-x2 root root 1024 Mar 9 2018 boot drwxr-xr-x 13 root root 2960 Dec 8 09:24 dev drwxr-xr-x 20 root root 1024 Dec 8 09:24 etc drwxr-xr-x3 root root 1024 Mar 9 2018 home drwxr-xr-x6 root root 1024 Mar 9 2018 lib drwx--2 root root 12288 Dec 8 09:22 lost+found drwxr-xr-x2 root root 1024 Mar 9 2018 media drwxr-xr-x2 root root 1024 Mar 9 2018 mnt dr-xr-xr-x 161 root root 0 Dec 8 09:24 proc drwxr-xr-x4 root root 240 Dec 8 09:24 run drwxr-xr-x2 root root 3072 Mar 9 2018 sbin dr-xr-xr-x 12 root root 0 Dec 8 09:24 sys drwxrwxrwt2 root root40 Dec 8 09:24 tmp drwxr-xr-x9 root root 1024 Mar 9 2018 usr drwxr-xr-x 10 root root 1024 Dec 8 09:24 var root@qemux86-64:/# cd /var/ root@qemux86-64:/var# ls -al drwxr-xr-x 10 root root 1024 Dec 8 09:24 . drwxr-xr-x 18 root root 1024 Dec 8 09:22 .. drwxr-xr-x2 root root 1024 Mar 9 2018 backups drwxr-xr-x2 root root 1024 Mar 9 2018 cache drwxr-xr-x4 root root 1024 Mar 9 2018 lib drwxr-xr-x2 root root 1024 Mar 9 2018 local lrwxrwxrwx1 root root 9 Dec 8 09:24 lock -> /run/lock drwxr-xr-x2 root root 1024 Dec 8 09:24 log
