Re: [Patch v4 2/6] user need make sure "path" on mounted fs has been created

[Vivek Goyal]

On Fri, Mar 21, 2014 at 05:55:19PM +0800, Baoquan He wrote:
> kdump need create the dir specified in "path" formerly if it does not
> exist. Now change the behavior to be that ueser takes charge of the
> "path", make sure "path" has been created, especially when separate disk
> is mounted on this "path".
>
> Also introduce 2 helper functions to help check the existence of path.
> Signed-off-by: Baoquan He
>
> kdump-lib.sh | 26 ++++++++++++++++++++++++++
>  mkdumprd     | 33 +--------------------------------
>  2 files changed, 27 insertions(+), 32 deletions(-)
>
> diff --git a/kdump-lib.sh b/kdump-lib.sh
> index fdcde83..6c90ed5 100755
> --- a/kdump-lib.sh
> +++ b/kdump-lib.sh
> @@ -82,3 +82,29 @@ get_mntpoint_from_target()
>      echo $(findmnt -k -f -n -r -o TARGET $1)
>  }
>
> +#This function compose a absolute path with the mount
> +#point and the relative $SAVE_PATH.
> +#target is passed in as argument, could be UUID, LABEL,
> +#block device or even nfs server export of the form of
> +#"my.server.com:/tmp/export"?
> +#And possibly this could be used for both default case
> +#as well as when dump taret is specified. When dump
> +#target is not specified, then $target would be null.
> +make_absolute_save_path()
> +{
> local _target=$1
> local _mnt
> _mnt=$(get_mntpoint_from_target $1)
> echo "${_mnt}/$SAVE_PATH"
>
> +}

Hmm..., Initially I was thinking that default dump target path will
make use of make_absolute_save_path(). But in patch3 it is not being
used. That means we don't have to expect that somebody will call 
above with _target=NULL. We can remove that from comments above.

In fact if somebody calls it with _target=NULL, then we will pass it
to get_mntoint_from_target(). That will return /proc for null target
argument and you will take that and return /proc/var/crash as absolute
path.

So remove above comments that _target can be null. Also it would be good
to return null if _target=null before caling get_mntpoint_from_target().

Thanks
Vivek
> +check_save_path_fs()
> +{
> local _path=$1
> if [ ! -d $_path ]; then
>    perror_exit "Dump path $_path does not exist."
> fi
>
> +}
>
> diff --git a/mkdumprd b/mkdumprd
> index 0295009..c8333a3 100644
> --- a/mkdumprd
> +++ b/mkdumprd
> @@ -173,37 +173,6 @@ mkdir_save_path_ssh()
>      return 0
>  }
>
> -#mkdir if save path does not exist on dump target filesystem
> -#$1=dump target
> -#caller should ensure $1 is mounted
> -mkdir_save_path_fs() {
> local _mnt=$(to_mount_point $1)
> local _remount="no"
> local _ret
> [ ! -d ${_mnt}/$SAVE_PATH ] && {
>    if is_readonly_mount $1; then
>        echo "Mounting $1 as read-write for creating dump directory.."
>        mount -o remount,rw $1 || {
>            perror_exit "Mounting $1 as read-write failed."
>        }
>        _remount="yes"
>    fi
>    mkdir -p ${_mnt}/$SAVE_PATH
>    _ret=$?
>    [ "$_remount" = "yes" ] && {
>        echo "Remounting $1 as read-only."
>        mount -o remount,ro $1 || {
>            perror_exit "Remounting $1 as read-only failed."
>        }
>    }
>    [ $_ret -ne 0 ] && {
>        perror_exit "Creating ${_mnt}/$SAVE_PATH failed."
>    }
> }
>
> -}
>
> #Function: get_fs_size
>  #$1=dump target
>  get_fs_size() {
> @@ -539,7 +508,7 @@ do
>              add_dracut_module "nfs"
>          fi
>          add_mount "$config_val"
>    mkdir_save_path_fs $config_val
>    check_save_path_fs $(make_absolute_save_path $config_val)
>    check_size fs $config_val
>    ;;
> raw)
>
> -- 
> 1.8.5.3