Re: [PATCH 1/1] latencytop: fix mount error

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2014-07-09 at 21:52 +0300, Roxana Ciobanu wrote:
> Added a check to ensure debugfs is not mounted before trying
> to mount it, because sysfs.sh already mounts it.
> 
> [ YOCTO #6498 ]
> 
> Signed-off-by: Roxana Ciobanu <roxana.ciobanu@intel.com>
> ---
>  .../latencytop-0.5/latencytop-fsync-mount.patch         | 17 +++++++++++++++++
>  meta/recipes-kernel/latencytop/latencytop_0.5.bb        |  5 +++--
>  2 files changed, 20 insertions(+), 2 deletions(-)
>  create mode 100644 meta/recipes-kernel/latencytop/latencytop-0.5/latencytop-fsync-mount.patch
> 
> diff --git a/meta/recipes-kernel/latencytop/latencytop-0.5/latencytop-fsync-mount.patch b/meta/recipes-kernel/latencytop/latencytop-0.5/latencytop-fsync-mount.patch
> new file mode 100644
> index 0000000..6de27d0
> --- /dev/null
> +++ b/meta/recipes-kernel/latencytop/latencytop-0.5/latencytop-fsync-mount.patch
> @@ -0,0 +1,17 @@
> +Index: latencytop-0.5/fsync.c
> +===================================================================
> +--- latencytop-0.5.orig/fsync.c	2014-07-09 16:56:32.565238023 +0300
> ++++ latencytop-0.5/fsync.c	2014-07-09 17:12:00.553237913 +0300
> +@@ -151,8 +151,10 @@
> +  * echo ftrace_printk > iter_ctrl 
> +  * echo 1 > tracing_on
> +  */
> +-	ret = system("/bin/mount -t debugfs none /sys/kernel/debug/");
> +-	if (!ret) 
> ++    ret = system("if ! grep -q debugfs /proc/filesystems; then"
> ++                 " /bin/mount -t debugfs none /sys/kernel/debug/"
> ++                 " else false; fi");
> ++    if (!ret)
> + 		return -1;
> + 	write_to_file("/sys/kernel/debug/tracing/current_tracer", "fsync");	
> + 	write_to_file("/sys/kernel/debug/tracing/iter_ctrl", "ftrace_printk");	

I'm not sure an upstream would accept what amounts to shell in the
system() call. Could we try listing that directories contents and then
only call the mount if the directory is empty/does not exist?

That patch should then be able to be sent upstream...

Cheers,

Richard


> diff --git a/meta/recipes-kernel/latencytop/latencytop_0.5.bb b/meta/recipes-kernel/latencytop/latencytop_0.5.bb
> index 516e2c5..9a95b92 100644
> --- a/meta/recipes-kernel/latencytop/latencytop_0.5.bb
> +++ b/meta/recipes-kernel/latencytop/latencytop_0.5.bb
> @@ -6,11 +6,12 @@ LIC_FILES_CHKSUM = "file://latencytop.c;endline=23;md5=ee9ea9b1415356e5734adad4a
>  
>  DEPENDS = "virtual/libintl ncurses glib-2.0  ${@bb.utils.contains('DISTRO_FEATURES', 'x11', 'gtk+', '', d)}"
>  
> -PR = "r3"
> +PR = "r4"
>  
>  SRC_URI = "http://www.latencytop.org/download/latencytop-${PV}.tar.gz \
>              file://latencytop-makefile.patch \
> -            file://latencytop-fsync.patch"
> +            file://latencytop-fsync.patch \
> +            file://latencytop-fsync-mount.patch"
>  
>  SRC_URI[md5sum] = "73bb3371c6ee0b0e68e25289027e865c"
>  SRC_URI[sha256sum] = "9e7f72fbea7bd918e71212a1eabaad8488d2c602205d2e3c95d62cd57e9203ef"
> -- 
> 1.9.1
>