Re: [PATCH] scripts: prune-kernel:remove old kernels and modules dir from system

[Randy Dunlap]

Hi,

On 10/30/19 2:54 AM, Bhaskar Chowdhury wrote:
> This patch will remove old kernels and modules directorey related
> to that kernel from the system by interactively and silently.Here
> are few interactions with the scripts
> 
> 1)
> 
> â ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
> 14:52 $ ./scripts/prune-kernel -h
> Usage: prune-kernel [ri]
> 
>  -r | --remove kernel_ver modules_dir_name
> 
>   -i | --interactive use as interactive way
>   â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
>   
>   14:52 $ ./scripts/prune-kernel --help
>   Usage: prune-kernel [ri]

That "[ri]" is confusing to me.

> 
>    -r | --remove kernel_ver modules_dir_na]
> 
>     -i | --interactive use as interactive way
>    
>  2)
> 
>  â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
>  14:52 $ ./scripts/prune-kernel -r 5.3.3
>  You need to provide kernel version and modules dir name
>  
>  â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
>  14:53 $ ./scripts/prune-kernel -r
>  You need to provide kernel version and modules dir name
>  
>  â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
>  14:54 $ ./scripts/prune-kernel -r 5.3.3 5.3.3-foo

This one above didn't remove any kernel files.
Needs more testing.

> 3)
> 
> $ ./scripts/prune-kernel --remove
> You need to provide kernel version and modules dir name
> 
> â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
> 14:55 $ ./scripts/prune-kernel --remove 5.3.3
> You need to provide kernel version and modules dir name
> 
> â-1 ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
> 14:55 $ ./scripts/prune-kernel --remove 5.3.3 5.3.3-foo
> 
> 
> 4)14:55 $ ./scripts/prune-kernel -i
> 
> Enter kernel version to remove or blank/empty to exit:
> 
> 
> 5)14:57 $ ./scripts/prune-kernel --interactive
> 
> Enter kernel version to remove or blank/empty to exit:
> â ~/git-linux/linux-kbuild [master|AM 1/1 âÂ59|â]
> 
> 
> 6)14:59 $ ./scripts/prune-kernel --interactive
> 
> Enter kernel version to remove or blank/empty to exit:5.3.3
> Please give the full modules directory name to remove:5.3.3-foo
> 
> 
> 
> Removed kernel version:5.3.3 and associated modules:5.3.3-foo ...Done.
> 
> 
> 7)15:00 $ ./scripts/prune-kernel -i
> 
> Enter kernel version to remove or blank/empty to exit:5.3.3
> Please give the full modules directory name to remove:5.3.3-foo
> 
> 
> 
> Removed kernel version:5.3.3 and associated modules:5.3.3-foo ...Done.
> 
> 
> Signed-off-by: Bhaskar Chowdhury <unixbhaskar@xxxxxxxxx>
> ---
>  scripts/prune-kernel | 63 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
> 
> diff --git a/scripts/prune-kernel b/scripts/prune-kernel
> index a25aa2160d47..a91010d0e2af 100755
> --- a/scripts/prune-kernel
> +++ b/scripts/prune-kernel
> @@ -1,3 +1,66 @@
>  #!/bin/bash
>  # SPDX-License-Identifier: GPL-2.0
> +#This script will delete old kernels and modules directory related to it
> +#-h with the script will show you the help
> +#-r with the script take two parameter: kernel_ver and modules_dir_name
> +#-i with the script allow you do the removing interactive way
> 
> +flag=$1
> +kernel_ver=$2
> +modules_dir_name=$3
> +boot_dir=/boot
> +modules_dir=/lib/modules
> +
> +remove_old_kernel() {
> +	cd $boot_dir
> +	rm -If vmlinuz-$kernel_version System.map-$kernel_version config-$kernel_version
> +	return 0
> +}
> +
> +remove_old_modules_dir() {
> +	cd $modules_dir
> +	rm -rf $modules_version
> +	return 0
> +}
> +
> +usage() {
> +	printf "Usage: $(basename $0) [ri] \n"
> +	printf "\n -r | --remove kernel_ver modules_dir_name \n"
> +	printf "\n -i | --interactive use as interactive way \n"
> +}
> +
> +for arg in "$@"

what is the purpose (use) of "arg" here?

what is the purpose of the for loop?

Is any 'shift' needed to consume (or discard) the first 3 positional
command line arguments?

> +do
> +	case "$flag" in
> +		-i | --interactive)
> +			printf "\nEnter kernel version to remove or blank/empty to exit:%s"
> +			read kernel_version
> +			if [[ $kernel_version != "" ]]; then
> +				remove_old_kernel
> +				printf "Please give the full modules directory name to remove:%s"
> +				read modules_version
> +				if [[ $modules_version != "" ]]; then
> +					remove_old_modules_dir
> +					printf "\n\n\n Removed kernel version:$kernel_version and associated modules:$modules_version ...Done. \n"

This message is only printed if $modules_version is non-empty.  If it is empty,
remove_old_kernel() has silently removed some kernel files (if they existed).

> +				else
> +					exit 1
> +				fi
> +			fi
> +			;;
> +		-h | --help)
> +			usage
> +			exit 1
> +			;;
> +		-r | --remove)
> +			if [[ $# -ne 3 ]]; then
> +				printf "You need to provide kernel version and modules dir name\n"
> +				exit 1
> +			else
> +				cd $boot_dir
> +				rm -f $kernel_ver

That 'rm' doesn't remove any files.  Compare what remove_old_kernel() does.

> +				cd $modules_dir
> +				rm -rf $modules_dir_name
> +			fi
> +			;;
> +	esac
> +done
> --

The script, after this patch is applied, still contains the old script's for-loop
at the end of the "new" prune-kernel script.

Nack.

-- 
~Randy