On 09/04/2013 06:10 PM, WANG Chao wrote:
> Cached CMDLINE doesn't work 100%. For example the following case,
>
> 1. dracut starts to run dracut-cmdline.sh. CMDLINE is cached when calling
> getarg 'rd.break=cmdline'.
> 2. In 92-parse-ibft.sh, ibft_to_cmdline() calls $(set_ifname ibft xx:xx..)
> multiple times in each subshell.
> 3. In 1st call, set_ifname() will check $(getargs ifname) and write out
> ifname=xxxx accordingly.
> 4. In 2nd call, set_ifname() will check $(getargs ifname) and it's wrong here.
> Because in step 3, we introduce a new cmdline arg ifname=xxx, but CMDLINE
> isn't updated. Thus we fail to get the new ifname arg.
>
> It's doable to unset CMDLINE every time after a new cmdline arg is in. But
> unset should be done in the parent process, because unset CMDLINE in a
> subshell won't unset CMDLINE in its parent or sibling process. And also it's
> painful to unset CMDLINE every time. In the future, functions and code
> snippet could probably separate or move to other file, the unset CMDLINE could
> malfunction again like this time.
>
> So I'm thinking not to cache CMDLINE. It's doesn't hurt to re-read all the
> cmdline args everytime. Because it's in initramfs, a non cached _getcmdline()
> should be fast enough.
>
> Please consider!
>
> Thanks
> WANG Chao
> ---
> modules.d/99base/dracut-lib.sh | 33 ++++++++++++++++-----------------
> 1 file changed, 16 insertions(+), 17 deletions(-)
>
> diff --git a/modules.d/99base/dracut-lib.sh b/modules.d/99base/dracut-lib.sh
> index 0d5cab9..ef8c5a3 100755
> --- a/modules.d/99base/dracut-lib.sh
> +++ b/modules.d/99base/dracut-lib.sh
> @@ -103,23 +103,22 @@ _getcmdline() {
> local _line
> local _i
> unset _line
> - if [ -z "$CMDLINE" ]; then
> - unset CMDLINE_ETC CMDLINE_ETC_D
> - if [ -e /etc/cmdline ]; then
> - while read -r _line; do
> - CMDLINE_ETC="$CMDLINE_ETC $_line";
> - done </etc/cmdline;
> - fi
> - for _i in /etc/cmdline.d/*.conf; do
> - [ -e "$_i" ] || continue
> - while read -r _line; do
> - CMDLINE_ETC_D="$CMDLINE_ETC_D $_line";
> - done <"$_i";
> - done
> - if [ -e /proc/cmdline ]; then
> - read -r CMDLINE </proc/cmdline;
> - CMDLINE="$CMDLINE_ETC_D $CMDLINE_ETC $CMDLINE"
> - fi
> + unset CMDLINE_ETC CMDLINE_ETC_D
> +
> + if [ -e /etc/cmdline ]; then
> + while read -r _line; do
> + CMDLINE_ETC="$CMDLINE_ETC $_line";
> + done </etc/cmdline;
> + fi
> + for _i in /etc/cmdline.d/*.conf; do
> + [ -e "$_i" ] || continue
> + while read -r _line; do
> + CMDLINE_ETC_D="$CMDLINE_ETC_D $_line";
> + done <"$_i";
> + done
> + if [ -e /proc/cmdline ]; then
> + read -r CMDLINE </proc/cmdline;
> + CMDLINE="$CMDLINE_ETC_D $CMDLINE_ETC $CMDLINE"
> fi
> }
>
>
Yes, you are right! Will merge! Thanks!!
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