[PATCH] Add mount -P to hide pseudo filesystems

[PATCH] Add mount -P to hide pseudo filesystems

[David Wilson]

This is just shorthand for an increasingly necessary yet cumbersome and
error-prone "grep -v" pipe. The alternative was to extend -t to accept
"nopseudofs", but that is tougher on the fingers.
---
 sys-utils/mount.8 |  4 ++++
 sys-utils/mount.c | 17 +++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/sys-utils/mount.8 b/sys-utils/mount.8
index 004a513..311b514 100644
--- a/sys-utils/mount.8
+++ b/sys-utils/mount.8
@@ -663,6 +663,10 @@ sections.
 .RE
 
 .TP
+.BR \-P , " \-\-no\-pseudofs"
+Inhibit listing of pseudo filesystem mounts. Only mounts backed by a network
+location or block device are displayed.
+.TP
 .BR \-R , " \-\-rbind"
 Remount a subtree and all possible submounts somewhere else (so that its
 contents are available in both places).  See above.
diff --git a/sys-utils/mount.c b/sys-utils/mount.c
index 73f9d0b..17dba9e 100644
--- a/sys-utils/mount.c
+++ b/sys-utils/mount.c
@@ -120,7 +120,8 @@ static void safe_fputs(const char *data)
 	}
 }
 
-static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
+static void print_all(struct libmnt_context *cxt, char *pattern,
+		      int show_label, int no_pseudofs)
 {
 	struct libmnt_table *tb;
 	struct libmnt_iter *itr = NULL;
@@ -147,6 +148,9 @@ static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
 
 		if (!mnt_fs_is_pseudofs(fs))
 			xsrc = mnt_pretty_path(src, cache);
+		else if (no_pseudofs)
+			continue;
+
 		printf ("%s on ", xsrc ? xsrc : src);
 		safe_fputs(mnt_fs_get_target(fs));
 
@@ -740,6 +744,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 	fprintf(out, _(
 	" -o, --options <list>    comma-separated list of mount options\n"
 	" -O, --test-opts <list>  limit the set of filesystems (use with -a)\n"
+	" -P, --no-pseudofs       inhibit listing of pseudo filesystems\n"
 	" -r, --read-only         mount the filesystem read-only (same as -o ro)\n"
 	" -t, --types <list>      limit the set of filesystem types\n"));
 	fprintf(out, _(
@@ -792,6 +797,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 int main(int argc, char **argv)
 {
 	int c, rc = MOUNT_EX_SUCCESS, all = 0, show_labels = 0;
+	int no_pseudofs = 0;
 	struct libmnt_context *cxt;
 	struct libmnt_table *fstab = NULL;
 	char *srcbuf = NULL;
@@ -842,6 +848,7 @@ int main(int argc, char **argv)
 		{ "make-rprivate", 0, 0, MOUNT_OPT_RPRIVATE },
 		{ "make-runbindable", 0, 0, MOUNT_OPT_RUNBINDABLE },
 		{ "no-canonicalize", 0, 0, 'c' },
+		{ "no-pseudofs", 0, 0, 'P' },
 		{ "internal-only", 0, 0, 'i' },
 		{ "show-labels", 0, 0, 'l' },
 		{ "target", 1, 0, MOUNT_OPT_TARGET },
@@ -869,12 +876,12 @@ int main(int argc, char **argv)
 
 	mnt_context_set_tables_errcb(cxt, table_parser_errcb);
 
-	while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:rRsU:vVwt:T:",
+	while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:PrRsU:vVwt:T:",
 					longopts, NULL)) != -1) {
 
 		/* only few options are allowed for non-root users */
 		if (mnt_context_is_restricted(cxt) &&
-		    !strchr("hlLUVvrist", c) &&
+		    !strchr("hlLUVvPrist", c) &&
 		    c != MOUNT_OPT_TARGET &&
 		    c != MOUNT_OPT_SOURCE)
 			exit_non_root(option_to_longopt(c, longopts));
@@ -939,6 +946,8 @@ int main(int argc, char **argv)
 		case 'l':
 			show_labels = 1;
 			break;
+		case 'P':
+			no_pseudofs = 1;
 		case 't':
 			types = optarg;
 			break;
@@ -1021,7 +1030,7 @@ int main(int argc, char **argv)
 	    !all) {
 		if (oper || mnt_context_get_options(cxt))
 			usage(stderr);
-		print_all(cxt, types, show_labels);
+		print_all(cxt, types, show_labels, no_pseudofs);
 		goto done;
 	}
 
-- 
2.1.4

Re: [PATCH] Add mount -P to hide pseudo filesystems

[Sami Kerola]

On 6 December 2015 at 04:29, David Wilson <dw@botanicus.net> wrote:
> This is just shorthand for an increasingly necessary yet cumbersome and
> error-prone "grep -v" pipe. The alternative was to extend -t to accept
> "nopseudofs", but that is tougher on the fingers.
> ---
>  sys-utils/mount.8 |  4 ++++
>  sys-utils/mount.c | 17 +++++++++++++----
>  2 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/sys-utils/mount.8 b/sys-utils/mount.8
> index 004a513..311b514 100644
> --- a/sys-utils/mount.8
> +++ b/sys-utils/mount.8
> @@ -663,6 +663,10 @@ sections.
>  .RE
>
>  .TP
> +.BR \-P , " \-\-no\-pseudofs"
> +Inhibit listing of pseudo filesystem mounts. Only mounts backed by a network
> +location or block device are displayed.
> +.TP
>  .BR \-R , " \-\-rbind"
>  Remount a subtree and all possible submounts somewhere else (so that its
>  contents are available in both places).  See above.
> diff --git a/sys-utils/mount.c b/sys-utils/mount.c
> index 73f9d0b..17dba9e 100644
> --- a/sys-utils/mount.c
> +++ b/sys-utils/mount.c
> @@ -120,7 +120,8 @@ static void safe_fputs(const char *data)
>         }
>  }
>
> -static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
> +static void print_all(struct libmnt_context *cxt, char *pattern,
> +                     int show_label, int no_pseudofs)
>  {
>         struct libmnt_table *tb;
>         struct libmnt_iter *itr = NULL;
> @@ -147,6 +148,9 @@ static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
>
>                 if (!mnt_fs_is_pseudofs(fs))
>                         xsrc = mnt_pretty_path(src, cache);
> +               else if (no_pseudofs)
> +                       continue;
> +
>                 printf ("%s on ", xsrc ? xsrc : src);
>                 safe_fputs(mnt_fs_get_target(fs));
>
> @@ -740,6 +744,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
>         fprintf(out, _(
>         " -o, --options <list>    comma-separated list of mount options\n"
>         " -O, --test-opts <list>  limit the set of filesystems (use with -a)\n"
> +       " -P, --no-pseudofs       inhibit listing of pseudo filesystems\n"
>         " -r, --read-only         mount the filesystem read-only (same as -o ro)\n"
>         " -t, --types <list>      limit the set of filesystem types\n"));
>         fprintf(out, _(
> @@ -792,6 +797,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
>  int main(int argc, char **argv)
>  {
>         int c, rc = MOUNT_EX_SUCCESS, all = 0, show_labels = 0;
> +       int no_pseudofs = 0;
>         struct libmnt_context *cxt;
>         struct libmnt_table *fstab = NULL;
>         char *srcbuf = NULL;
> @@ -842,6 +848,7 @@ int main(int argc, char **argv)
>                 { "make-rprivate", 0, 0, MOUNT_OPT_RPRIVATE },
>                 { "make-runbindable", 0, 0, MOUNT_OPT_RUNBINDABLE },
>                 { "no-canonicalize", 0, 0, 'c' },
> +               { "no-pseudofs", 0, 0, 'P' },

Hi David,

I doubt this is common enough case to assign short option.  How about
long-only option, see MOUNT_OPT_RUNBINDABLE for an example how to make
that work.


>                 { "internal-only", 0, 0, 'i' },
>                 { "show-labels", 0, 0, 'l' },
>                 { "target", 1, 0, MOUNT_OPT_TARGET },
> @@ -869,12 +876,12 @@ int main(int argc, char **argv)
>
>         mnt_context_set_tables_errcb(cxt, table_parser_errcb);
>
> -       while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:rRsU:vVwt:T:",
> +       while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:PrRsU:vVwt:T:",
>                                         longopts, NULL)) != -1) {
>
>                 /* only few options are allowed for non-root users */
>                 if (mnt_context_is_restricted(cxt) &&
> -                   !strchr("hlLUVvrist", c) &&
> +                   !strchr("hlLUVvPrist", c) &&
>                     c != MOUNT_OPT_TARGET &&
>                     c != MOUNT_OPT_SOURCE)
>                         exit_non_root(option_to_longopt(c, longopts));
> @@ -939,6 +946,8 @@ int main(int argc, char **argv)
>                 case 'l':
>                         show_labels = 1;
>                         break;
> +               case 'P':
> +                       no_pseudofs = 1;
>                 case 't':
>                         types = optarg;
>                         break;
> @@ -1021,7 +1030,7 @@ int main(int argc, char **argv)
>             !all) {
>                 if (oper || mnt_context_get_options(cxt))
>                         usage(stderr);
> -               print_all(cxt, types, show_labels);
> +               print_all(cxt, types, show_labels, no_pseudofs);
>                 goto done;
>         }
>
> --
> 2.1.4
> --
> To unsubscribe from this list: send the line "unsubscribe util-linux" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Sami Kerola
http://www.iki.fi/kerolasa/

Re: [PATCH] Add mount -P to hide pseudo filesystems

[David Wilson]

On 6 December 2015 at 10:22, Sami Kerola <kerolasa@iki.fi> wrote:
> On 6 December 2015 at 04:29, David Wilson <dw@botanicus.net> wrote:
>> This is just shorthand for an increasingly necessary yet cumbersome and
>> error-prone "grep -v" pipe. The alternative was to extend -t to accept
>> "nopseudofs", but that is tougher on the fingers.
>> ---
>>  sys-utils/mount.8 |  4 ++++
>>  sys-utils/mount.c | 17 +++++++++++++----
>>  2 files changed, 17 insertions(+), 4 deletions(-)
>>
>> diff --git a/sys-utils/mount.8 b/sys-utils/mount.8
>> index 004a513..311b514 100644
>> --- a/sys-utils/mount.8
>> +++ b/sys-utils/mount.8
>> @@ -663,6 +663,10 @@ sections.
>>  .RE
>>
>>  .TP
>> +.BR \-P , " \-\-no\-pseudofs"
>> +Inhibit listing of pseudo filesystem mounts. Only mounts backed by a network
>> +location or block device are displayed.
>> +.TP
>>  .BR \-R , " \-\-rbind"
>>  Remount a subtree and all possible submounts somewhere else (so that its
>>  contents are available in both places).  See above.
>> diff --git a/sys-utils/mount.c b/sys-utils/mount.c
>> index 73f9d0b..17dba9e 100644
>> --- a/sys-utils/mount.c
>> +++ b/sys-utils/mount.c
>> @@ -120,7 +120,8 @@ static void safe_fputs(const char *data)
>>         }
>>  }
>>
>> -static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
>> +static void print_all(struct libmnt_context *cxt, char *pattern,
>> +                     int show_label, int no_pseudofs)
>>  {
>>         struct libmnt_table *tb;
>>         struct libmnt_iter *itr = NULL;
>> @@ -147,6 +148,9 @@ static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
>>
>>                 if (!mnt_fs_is_pseudofs(fs))
>>                         xsrc = mnt_pretty_path(src, cache);
>> +               else if (no_pseudofs)
>> +                       continue;
>> +
>>                 printf ("%s on ", xsrc ? xsrc : src);
>>                 safe_fputs(mnt_fs_get_target(fs));
>>
>> @@ -740,6 +744,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
>>         fprintf(out, _(
>>         " -o, --options <list>    comma-separated list of mount options\n"
>>         " -O, --test-opts <list>  limit the set of filesystems (use with -a)\n"
>> +       " -P, --no-pseudofs       inhibit listing of pseudo filesystems\n"
>>         " -r, --read-only         mount the filesystem read-only (same as -o ro)\n"
>>         " -t, --types <list>      limit the set of filesystem types\n"));
>>         fprintf(out, _(
>> @@ -792,6 +797,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
>>  int main(int argc, char **argv)
>>  {
>>         int c, rc = MOUNT_EX_SUCCESS, all = 0, show_labels = 0;
>> +       int no_pseudofs = 0;
>>         struct libmnt_context *cxt;
>>         struct libmnt_table *fstab = NULL;
>>         char *srcbuf = NULL;
>> @@ -842,6 +848,7 @@ int main(int argc, char **argv)
>>                 { "make-rprivate", 0, 0, MOUNT_OPT_RPRIVATE },
>>                 { "make-runbindable", 0, 0, MOUNT_OPT_RUNBINDABLE },
>>                 { "no-canonicalize", 0, 0, 'c' },
>> +               { "no-pseudofs", 0, 0, 'P' },
>
> Hi David,
>
> I doubt this is common enough case to assign short option.  How about
> long-only option, see MOUNT_OPT_RUNBINDABLE for an example how to make
> that work.

I agree, although I see little value in a patch if it becomes hard to
type. At that point copying around a wrapper script named 'mountp' is
probably easier. :)

How about some shorter spelling for --no-pseudofs, say, --real or
--plain, or maybe it just becomes neater to extend -t. How about
spellings of -t like:

"-t [no]pseudo" -> anon_inodefs,bdev,cgroup,..,tmpfs
"-t [no]net" -> cifs,smbfs,...,9p
"-t [no]plain" -> nopseudo,nonet


David

>
>
>>                 { "internal-only", 0, 0, 'i' },
>>                 { "show-labels", 0, 0, 'l' },
>>                 { "target", 1, 0, MOUNT_OPT_TARGET },
>> @@ -869,12 +876,12 @@ int main(int argc, char **argv)
>>
>>         mnt_context_set_tables_errcb(cxt, table_parser_errcb);
>>
>> -       while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:rRsU:vVwt:T:",
>> +       while ((c = getopt_long(argc, argv, "aBcfFhilL:Mno:O:PrRsU:vVwt:T:",
>>                                         longopts, NULL)) != -1) {
>>
>>                 /* only few options are allowed for non-root users */
>>                 if (mnt_context_is_restricted(cxt) &&
>> -                   !strchr("hlLUVvrist", c) &&
>> +                   !strchr("hlLUVvPrist", c) &&
>>                     c != MOUNT_OPT_TARGET &&
>>                     c != MOUNT_OPT_SOURCE)
>>                         exit_non_root(option_to_longopt(c, longopts));
>> @@ -939,6 +946,8 @@ int main(int argc, char **argv)
>>                 case 'l':
>>                         show_labels = 1;
>>                         break;
>> +               case 'P':
>> +                       no_pseudofs = 1;
>>                 case 't':
>>                         types = optarg;
>>                         break;
>> @@ -1021,7 +1030,7 @@ int main(int argc, char **argv)
>>             !all) {
>>                 if (oper || mnt_context_get_options(cxt))
>>                         usage(stderr);
>> -               print_all(cxt, types, show_labels);
>> +               print_all(cxt, types, show_labels, no_pseudofs);
>>                 goto done;
>>         }
>>
>> --
>> 2.1.4
>> --
>> To unsubscribe from this list: send the line "unsubscribe util-linux" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
> --
> Sami Kerola
> http://www.iki.fi/kerolasa/

Re: [PATCH] Add mount -P to hide pseudo filesystems

[Sami Kerola]

On 6 December 2015 at 12:39, David Wilson <dw@botanicus.net> wrote:
> On 6 December 2015 at 10:22, Sami Kerola <kerolasa@iki.fi> wrote:
>> On 6 December 2015 at 04:29, David Wilson <dw@botanicus.net> wrote:
>>> @@ -842,6 +848,7 @@ int main(int argc, char **argv)
>>>                 { "make-rprivate", 0, 0, MOUNT_OPT_RPRIVATE },
>>>                 { "make-runbindable", 0, 0, MOUNT_OPT_RUNBINDABLE },
>>>                 { "no-canonicalize", 0, 0, 'c' },
>>> +               { "no-pseudofs", 0, 0, 'P' },
>>
>> Hi David,
>>
>> I doubt this is common enough case to assign short option.  How about
>> long-only option, see MOUNT_OPT_RUNBINDABLE for an example how to make
>> that work.
>
> I agree, although I see little value in a patch if it becomes hard to
> type. At that point copying around a wrapper script named 'mountp' is
> probably easier. :)
>
> How about some shorter spelling for --no-pseudofs, say, --real or
> --plain, or maybe it just becomes neater to extend -t. How about
> spellings of -t like:
>
> "-t [no]pseudo" -> anon_inodefs,bdev,cgroup,..,tmpfs
> "-t [no]net" -> cifs,smbfs,...,9p
> "-t [no]plain" -> nopseudo,nonet

Hi David,

Maybe you can rely gnu getops doing the right thing with '--no-p' when
typing. In scripts I recommend to use the full option. Try the
following ls(1) examples to see how the getops allows truncating long
options. I think it is unfortunate option shortening is not widely
know.

ls --h
ls --he

-- 
Sami Kerola
http://www.iki.fi/kerolasa/

Re: [PATCH] Add mount -P to hide pseudo filesystems

[Karel Zak]

On Sun, Dec 06, 2015 at 04:29:23AM +0000, David Wilson wrote:
> This is just shorthand for an increasingly necessary yet cumbersome and
> error-prone "grep -v" pipe. The alternative was to extend -t to accept
> "nopseudofs", but that is tougher on the fingers.

 I don't plan to improve mount(8) list output in any way to duplicate
 findmnt(8). Please, let's use (and improve) findmnt(8). Thanks.

 Anyway,

     --real
     --net
     --pseudo
 
 sounds good for findmnt. Look forward for a patch :-)

    Karel


-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: [PATCH] Add mount -P to hide pseudo filesystems

[Bruce Dubbs]

Karel Zak wrote:
> On Sun, Dec 06, 2015 at 04:29:23AM +0000, David Wilson wrote:
>> This is just shorthand for an increasingly necessary yet cumbersome and
>> error-prone "grep -v" pipe. The alternative was to extend -t to accept
>> "nopseudofs", but that is tougher on the fingers.
>
>   I don't plan to improve mount(8) list output in any way to duplicate
>   findmnt(8). Please, let's use (and improve) findmnt(8). Thanks.
>
>   Anyway,
>
>       --real
>       --net
>       --pseudo
>
>   sounds good for findmnt. Look forward for a patch :-)

Is it possible to detect --bind in findmnt?

   -- Bruce

Re: [PATCH] Add mount -P to hide pseudo filesystems

[Karel Zak]

On Mon, Dec 07, 2015 at 09:10:48AM -0600, Bruce Dubbs wrote:
> Karel Zak wrote:
> >On Sun, Dec 06, 2015 at 04:29:23AM +0000, David Wilson wrote:
> >>This is just shorthand for an increasingly necessary yet cumbersome and
> >>error-prone "grep -v" pipe. The alternative was to extend -t to accept
> >>"nopseudofs", but that is tougher on the fingers.
> >
> >  I don't plan to improve mount(8) list output in any way to duplicate
> >  findmnt(8). Please, let's use (and improve) findmnt(8). Thanks.
> >
> >  Anyway,
> >
> >      --real
> >      --net
> >      --pseudo
> >
> >  sounds good for findmnt. Look forward for a patch :-)
> 
> Is it possible to detect --bind in findmnt?

No, nowhere in the system is information about a way how the
filesystem has been mounted to the system. (Well, except obsolete
classic /etc/mtab.)

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com