[openwrt/openwrt] base-files: sysupgrade: Add 2 sec sleep into process KILL loop

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch openwrt-23.05:
https://git.openwrt.org/6577b550df89766d10375aacc87c56a4658c3776

commit 6577b550df89766d10375aacc87c56a4658c3776
Author: Hannu Nyman <hannu.nyman at iki.fi>
AuthorDate: Fri Sep 8 19:47:01 2023 +0300

    base-files: sysupgrade: Add 2 sec sleep into process KILL loop
    
    Add 2 seconds sleep after each forcibly killed/tried-to-kill process
    in the final process termination loop in sysupgrade stage2.
    
    This is needed especially for qualcommax/ipq807x, where ath11k
    wireless driver may have a long 10-20 seconds delay after termination
    before actually getting killed. This often breaks sysupgrade.
    
    The current KILL loop in kill_remaining does all 10 kill attempts
    consecutively without any delay, as evidenced here in a failing sysupgrade.
    It does not allow any time for the process to finalize its internal
    termination.
    
    Sat Sep  2 19:05:56 EEST 2023 upgrade: Sending TERM to remaining processes ...
    Sat Sep  2 19:05:56 EEST 2023 upgrade: Sending signal TERM to hostapd (2122)
    Sat Sep  2 19:05:56 EEST 2023 upgrade: Sending signal TERM to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending KILL to remaining processes ...
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2122)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Sending signal KILL to hostapd (2138)
    Sat Sep  2 19:06:00 EEST 2023 upgrade: Failed to kill all processes.
    sysupgrade aborted with return code: 256
    
    The change in this commit adds a 2 seconds delay after each kill attempt
    in order to allow some processes to more gracefully handle their
    internal termination.
    
    The result is like this:
    
    Sun Sep  3 11:15:10 EEST 2023 upgrade: Sending TERM to remaining processes ...
    Sun Sep  3 11:15:10 EEST 2023 upgrade: Sending signal TERM to hostapd (2309)
    Sun Sep  3 11:15:10 EEST 2023 upgrade: Sending signal TERM to hostapd (2324)
    Sun Sep  3 11:15:14 EEST 2023 upgrade: Sending KILL to remaining processes ...
    Sun Sep  3 11:15:14 EEST 2023 upgrade: Sending signal KILL to hostapd (2309)
    [  699.827521] br-lan: port 7(hn5wpa2r) entered disabled state
    [  699.908673] device hn5wpa2r left promiscuous mode
    [  699.908721] br-lan: port 7(hn5wpa2r) entered disabled state
    [  701.038029] br-lan: port 6(hn5wpa3) entered disabled state
    Sun Sep  3 11:15:16 EEST 2023 upgrade: Sending signal KILL to hostapd (2324)
    [  702.058256] br-lan: port 5(hn2wlan) entered disabled state
    [  709.250063] stage2 (8237): drop_caches: 3
    Sun Sep  3 11:15:25 EEST 2023 upgrade: Switching to ramdisk...
    
    The delay introduced here only kicks in if there is some process that
    does not get terminated by the first TERM call. Then there is at least
    one 2 sec wait after the first KILL loop round.
    
    This commit is related to discussion in PRs #12235 and #12632
    
    Signed-off-by: Hannu Nyman <hannu.nyman at iki.fi>
    Reviewed-by: Robert Marko <robimarko at gmail.com>
    (cherry picked from commit 47d56ae5463f1965750d3f75390c96d69f969145)
---
 package/base-files/files/lib/upgrade/stage2 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/base-files/files/lib/upgrade/stage2 b/package/base-files/files/lib/upgrade/stage2
index f4db88d31e..5ce0b3549c 100755
--- a/package/base-files/files/lib/upgrade/stage2
+++ b/package/base-files/files/lib/upgrade/stage2
@@ -121,7 +121,7 @@ kill_remaining() { # [ <signal> [ <loop> ] ]
 			v "Sending signal $sig to $name ($pid)"
 			kill -$sig $pid 2>/dev/null
 
-			[ $loop -eq 1 ] && run=true
+			[ $loop -eq 1 ] && sleep 2 && run=true
 		done
 
 		let loop_limit--