Re: [PATCH] autofs: fix the wrong usage of the deprecated task_pgrp_nr()

Ian Kent
2009-01-19T02:20:21Z

On Sun, 2009-01-18 at 08:34 +0100, Oleg Nesterov wrote:
> parse_options(&pgid) sets pgid = task_pgrp_nr() which uses the global
> namespace. This is wrong, we use this pgid to find "struct pid" in the
> current's namespace. Change parse_options() to use task_pgrp_vnr().
>
> Also do s/task_pgrp_nr/task_pgrp_vnr/ in the debugging printks.
> checkpatch.pl complains about "line over 80 characters", but it should
> blame the cuurent code, not the patch.

This changelog entry doesn't really have anything that I can use to work
out if this change might introduce regressions.

It would be helpful to me if you could include:
1) A brief statement about what your trying to achieve and why.
2) The reason why task_pgrp_nr() has changed to task_pgrp_vnr() since
you made the change (that is someone working on pid namespaces) to
task_pgrp_nr().
3) Why you believe this change won't introduce a regression.

>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
>
> --- CUR/fs/autofs/inode.c~1_AUTOFS 2009-01-12 23:07:46.000000000 +0100
> +++ CUR/fs/autofs/inode.c 2009-01-18 06:18:49.000000000 +0100
> @@ -78,7 +78,7 @@ static int parse_options(char *options,
>
> *uid = current_uid();
> *gid = current_gid();
> - *pgrp = task_pgrp_nr(current);
> + *pgrp = task_pgrp_vnr(current);
>
> *minproto = *maxproto = AUTOFS_PROTO_VERSION;
>
> --- CUR/fs/autofs/root.c~1_AUTOFS 2008-10-10 00:13:53.000000000 +0200
> +++ CUR/fs/autofs/root.c 2009-01-18 06:15:42.000000000 +0100
> @@ -215,7 +215,7 @@ static struct dentry *autofs_root_lookup
> oz_mode = autofs_oz_mode(sbi);
> DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
> "oz_mode = %d\n", task_pid_nr(current),
> - task_pgrp_nr(current), sbi->catatonic,
> + task_pgrp_vnr(current), sbi->catatonic,
> oz_mode));
>
> /*
> @@ -550,7 +550,8 @@ static int autofs_root_ioctl(struct inod
> struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
> void __user *argp = (void __user *)arg;
>
> - DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
> + DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
> + cmd, arg, sbi, task_pgrp_vnr(current)));
>
> if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
> _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
>