uci: unnecessary write accesses
Florian Eckert
fe at dev.tdt.de
Tue Sep 21 04:19:43 PDT 2021
I have written a small shell script, to track write access to the
'/etc/config' directory.
For this task I am using the inotify-tool package [1].
I am using the inotifywait tool to add the watchers [2] with a small
shell script and log them to the syslog.
If I change a 'uci' option with the the 'uci' commands, then I get
create and write events for a temporary file in the '/etc/config/'
directory.
I didn't expect it to be like this.
For example, if I now change a file using the 'uci' command, a tmp file
is created under '/etc/config'.
Is this correct? Or do we have a problem there.
I have always thought that for embedded systems with flashes it is
important to make as few write accesses as possible.
Shell commands to change uci config:
root at st-dev-07 ~ # uci set system.led_Power.trigger=none
root at st-dev-07 ~ # uci commit system
Log output of my Script:
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"CREATE","time":"09/21/21
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"MODIFY","time":"09/21/21
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"MODIFY","time":"09/21/21
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"CLOSE_WRITE,CLOSE","time":"09/21/21
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":"system","event":"CLOSE_WRITE,CLOSE","time":"09/21/21
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]:
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"ATTRIB","time":"09/21/21
12:50:38"}
I am bothered about the file '.system.uci-fEGgbp'?
To do this without my script on the console, the following command can
be used on the shell:
inotifywait --quiet --monitor -e
"create,delete,modify,close_write,attrib" /etc/config
Then you will get the following output if you change an option with uci:
/etc/config/ CREATE .system.uci-lOlFid
/etc/config/ MODIFY .system.uci-lOlFid
/etc/config/ MODIFY .system.uci-lOlFid
/etc/config/ CLOSE_WRITE,CLOSE .system.uci-lOlFid
/etc/config/ CLOSE_WRITE,CLOSE system
/etc/config/ ATTRIB .system.uci-lOlFid
---
Florian
[1]
https://github.com/openwrt/packages/blob/master/utils/inotify-tools/Makefile
[2] https://www.man7.org/linux/man-pages/man1/inotifywait.1.html
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