[PATCH] mountpoint: drop S_ISDIR check

[PATCH] mountpoint: drop S_ISDIR check

[Dave Reisner]

Files can be mountpoints, too.
---
I can't find any reason for this check -- it seems to have existed since
mountpoint was added to the util-linux tree.

 sys-utils/mountpoint.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/sys-utils/mountpoint.c b/sys-utils/mountpoint.c
index cba5f01..3919ab7 100644
--- a/sys-utils/mountpoint.c
+++ b/sys-utils/mountpoint.c
@@ -192,12 +192,6 @@ int main(int argc, char **argv)
 	else {
 		dev_t src;
 
-		if (!S_ISDIR(st.st_mode)) {
-			if (!quiet)
-				errx(EXIT_FAILURE, _("%s: not a directory"), spec);
-			return EXIT_FAILURE;
-		}
-
 		if ( dir_to_device(spec, &src)) {
 			if (!quiet)
 				printf(_("%s is not a mountpoint\n"), spec);
-- 
2.1.0

Re: [PATCH] mountpoint: drop S_ISDIR check

[Karel Zak]

On Thu, Aug 21, 2014 at 08:48:12AM -0400, Dave Reisner wrote:
>  sys-utils/mountpoint.c | 6 ------
>  1 file changed, 6 deletions(-)

 Applied, thanks.

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

Re: [PATCH] mountpoint: drop S_ISDIR check

[Bernhard Voelker]

On 08/21/2014 02:48 PM, Dave Reisner wrote:
> Files can be mountpoints, too.

just out of curiosity - how?

 $ touch /tmp/mountpoint
 $ mount -t proc proc /tmp/mountpoint
 mount: mount point /tmp/mountpoint is not a directory

Thanks & have a nice day,
Berny

Re: [PATCH] mountpoint: drop S_ISDIR check

[Adam Sampson]

Bernhard Voelker <mail@bernhard-voelker.de> writes:

> just out of curiosity - how?

It's certainly possible with bind mounts:

  # touch /foo
  # mount --bind /etc/hostname /foo
  # mountpoint /foo
  mountpoint: /foo: not a directory

(whereas it works fine for a bind-mounted directory).

However, the mountpoint(1) man page talks explicitly about the argument
being a directory, so that should probably be updated as well if it now
works on files too.

-- 
Adam Sampson <ats@offog.org>                         <http://offog.org/>

Re: [PATCH] mountpoint: drop S_ISDIR check

[Dave Reisner]

On Thu, Aug 21, 2014 at 04:56:58PM +0200, Bernhard Voelker wrote:
> On 08/21/2014 02:48 PM, Dave Reisner wrote:
> > Files can be mountpoints, too.
> 
> just out of curiosity - how?
> 
>  $ touch /tmp/mountpoint
>  $ mount -t proc proc /tmp/mountpoint
>  mount: mount point /tmp/mountpoint is not a directory
> 
> Thanks & have a nice day,
> Berny

You cannot mount a file on a directory, but you can mount a file on a
file.

Cheers,
d

[PATCH] mountpoint.1: clarify that it works on files

[Dave Reisner]

fef4dfa174 removed the restriction that the argument must explicitly be
a directory, so let's fix up the documentation to reflect that.
---
 sys-utils/mountpoint.1 | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sys-utils/mountpoint.1 b/sys-utils/mountpoint.1
index 29c153c..078ba25 100644
--- a/sys-utils/mountpoint.1
+++ b/sys-utils/mountpoint.1
@@ -1,11 +1,13 @@
 .\" -*- nroff -*-
 .TH MOUNTPOINT 1 "July 2014" "util-linux" "User Commands"
 .SH NAME
-mountpoint \- see if a directory is a mountpoint
+mountpoint \- see if a directory or file is a mountpoint
 .SH SYNOPSIS
 .B mountpoint
 .RB [ \-d | \-q ]
 .I directory
+|
+.I file
 .sp
 .B mountpoint
 .B \-x
@@ -15,6 +17,8 @@ mountpoint \- see if a directory is a mountpoint
 .B mountpoint
 checks whether the given
 .I directory
+or
+.I file
 is mentioned in the /proc/self/mountinfo file.
 .SH OPTIONS
 .TP
@@ -34,7 +38,7 @@ Display version information and exit.
 .BR \-h , " \-\-help"
 Display help text and exit.
 .SH EXIT STATUS
-Zero if the directory is a mountpoint, non-zero if not.
+Zero if the directory or file is a mountpoint, non-zero if not.
 .SH AUTHOR
 .PP
 Karel Zak <kzak@redhat.com>
-- 
2.1.0

Re: [PATCH] mountpoint.1: clarify that it works on files

[Karel Zak]

On Thu, Aug 21, 2014 at 12:16:57PM -0400, Dave Reisner wrote:
>  sys-utils/mountpoint.1 | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)

 Applied, thanks.

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