On Wed, Apr 01, 2015 at 09:12:30PM -0400, Mike Frysinger wrote:
> On 01 Apr 2015 23:38, Karel Zak wrote:
> > On Wed, Apr 01, 2015 at 10:06:52PM +0100, Ruediger Meier wrote:
> > > > > Maybe both cases also with or without fallback $sbindir, /sbin or
> > > > > $PATH.
> > > > >
> > > > > I guess we should agree how somthing like this should be handeled
> > > > > in general. "eject" is also using hardcoded "/bin/umount".
> > > >
> > > > seems like $PATH should always be used. if you broke $PATH, well
> >
> > Yes, agree.
> >
> > Note that we already have and use FS_SEARCH_PATH in mkfs, fsck and
> > mount (libmount), see --enable-fs-paths-default and --enable-fs-paths-extra.
>
> what's the reason for having FS_SEARCH_PATH anymore ?
If I good remember then the reason is that the helpers does not have
to be installed in standard PATH. Well, you're author of this thing
:-)
commit bb4cb69df2a7fba3098f073aa4b758a8011d826f
Author: Mike Frysinger <vapier@xxxxxxxxxx>
Date: Sun Jan 24 22:36:55 2010 -0500
fsck/mkfs/mount: unify default search paths for helpers
> neither tool is set*id,
> and mkfs/fsck generally live in /sbin. i guess if you're non-root and have
> /sbin/mkfs hardcoded in a script, then dropping FS_SEARCH_PATH might break
> existing code.
for systemd based distors the path should be also modified, we have
all in /usr and /sbin and /bin are symlinks only.
> looking a bit at the code, i see that --disable-fs-paths-default almost does the
> right thing. but the actual implementations are inconsistent leading to
> weirdness.
>
> fsck adds / to the search:
> ...
> static const char fsck_prefix_path[] = FS_SEARCH_PATH;
> ...
> char *oldpath = getenv("PATH");
> ...
> if (oldpath) {
> fsck_path = xmalloc (strlen (fsck_prefix_path) + 1 +
> strlen (oldpath) + 1);
> strcpy (fsck_path, fsck_prefix_path);
> strcat (fsck_path, ":");
> strcat (fsck_path, oldpath);
> ...
> tpl = (strncmp(type, "fsck.", 5) ? "%s/fsck.%s" : "%s/%s");
>
> for(s = strtok(p, ":"); s; s = strtok(NULL, ":")) {
> sprintf(prog, tpl, s, type);
> if (stat(prog, &st) == 0)
> break;
> }
> ...
>
> mkfs adds the cwd to $PATH, and hardcodes /bin too:
> ...
> #define SEARCH_PATH "PATH=" FS_SEARCH_PATH
> ...
> /* Set PATH and program name */
> oldpath = getenv("PATH");
> if (!oldpath)
> oldpath = "/bin";
>
> newpath = xmalloc(strlen(oldpath) + sizeof(SEARCH_PATH) + 3);
> sprintf(newpath, "%s:%s\n", SEARCH_PATH, oldpath);
> putenv(newpath);
> ...
>
> libmount only searches FS_SEARCH_PATH:
> ...
> char search_path[] = FS_SEARCH_PATH; /* from config.h */
> ...
> path = strtok_r(search_path, ":", &p);
> while (path) {
> ...
>
> > Maybe we can use it use FS_SEARCH_PATH also for mkswap in swapon, or use it
> > as fallback.
>
> my preference would be to not move more tools into that system and allow any
> more implicit lookups to leak out.
I'm happy that for example mount(8) does not waste time with all PATH,
but it cares about /sbin only. IMHO it's fine that mkfs, mount and
fsck assume *helpers* on specific place. The mkswap is different, it's
standard command and it's expected in PATH.
Karel
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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