Bug: "could not open backing-store directory: /usr/lib/tgt/backing-store" message at startup

Bug: "could not open backing-store directory: /usr/lib/tgt/backing-store" message at startup

[Lee Duncan]

Hello:

I have found a small problem recently when tgtd is configured for no
back-end support modules.

The Makefile in usr has these lines:

> install: $(PROGRAMS) $(MODULES)
> 	install -d -m 755 $(DESTDIR)$(sbindir)
> 	install -m 755 $(PROGRAMS) $(DESTDIR)$(sbindir)
> ifneq ($(MODULES),)
> 	install -d -m 755 $(DESTDIR)$(libdir)/backing-store
> 	install -m 755 $(MODULES) $(DESTDIR)$(libdir)/backing-store
> endif
> 

So if no modules are defined, that the backing-store directory will
never get created. Which makes sense I suppose -- it will never be
needed, since it is only used for modules.

But then the code in usr/bs.c seems to consider it an error when the
directory does not exist:

> static int bs_init_signalfd(void)
> {
> 	sigset_t mask;
> 	int ret;
> 	DIR *dir;
> 
> 	dir = opendir(BSDIR);
> 	if (dir == NULL) {
> 		eprintf("could not open backing-store module directory %s\n",
> 			BSDIR);
> 	} else {
> ...
> }

causing an error message each time tgtd starts, and this shows up on the
systemd status output, which is not good.

This seems like more of an informational message in this case, since the
bs_init_signalfd() function does not return a failure code in this case.

It seems like the "right" way to fix it would be change this code to not
consider this case an error -- perhaps just a debugging message?

Another simple solution would be to change the Makefile so that the
backing-store directory always gets created, and only the installation
of MODULES becomes conditional on having MODULES.

I can supply a patch for either case. Which would you prefer?
-- 
Lee Duncan

Re: Bug: "could not open backing-store directory: /usr/lib/tgt/backing-store" message at startup

[FUJITA Tomonori]

Hi,

On Fri, 13 Nov 2015 20:36:47 +0100
Lee Duncan <lduncan@suse.com> wrote:

> It seems like the "right" way to fix it would be change this code to not
> consider this case an error -- perhaps just a debugging message?

Sounds reasonable to me. Can you send a patch?

Thanks,

backing-store modules directory not present is not an error

[Lee Duncan]

The backing-store modules directory, normally
/usr/lib/tgt/backing-store, is not created, needed, or used when there
are no backing store modules. So change the error message printed when
the directory is not present to a debug message.

Signed-off-by: Lee Duncan <lduncan@suse.com>
---
diff -aurp tgt-1.0.44.orig/usr/bs.c tgt-1.0.44/usr/bs.c
--- tgt-1.0.44.orig/usr/bs.c	2014-02-02 22:56:32.000000000 -0800
+++ tgt-1.0.44/usr/bs.c	2015-11-15 17:14:51.932000000 -0800
@@ -267,7 +267,8 @@ static int bs_init_signalfd(void)

 	dir = opendir(BSDIR);
 	if (dir == NULL) {
-		eprintf("could not open backing-store module directory %s\n",
+		/* not considered an error if there are no modules */
+		dprintf("could not open backing-store module directory %s\n",
 			BSDIR);
 	} else {
 		struct dirent *dirent;

Re: backing-store modules directory not present is not an error

[FUJITA Tomonori]

On Sun, 15 Nov 2015 17:15:51 -0800
Lee Duncan <lduncan@suse.com> wrote:

> The backing-store modules directory, normally
> /usr/lib/tgt/backing-store, is not created, needed, or used when there
> are no backing store modules. So change the error message printed when
> the directory is not present to a debug message.
> 
> Signed-off-by: Lee Duncan <lduncan@suse.com>

Applied, thanks.