[PATCH] autofs4 - zero timeout prevents shutdown

[PATCH] autofs4 - zero timeout prevents shutdown

[Ian Kent]

Hi Andrew,

If the timeout of an autofs mount is set to zero then umounts
are disabled. This works fine, however the kernel module checks
the expire timeout and goes no further if it is zero. This is
not the right thing to do at shutdown as the module is passed
an option to expire mounts regardless of their timeout setting.

This patch allows autofs to honor the force expire option.

Signed-off-by: Ian Kent <raven@themaw.net>

---

--- linux-2.6.18-rc6-mm2/fs/autofs4/expire.c.zero-timeout	2006-09-14 10:25:55.000000000 +0800
+++ linux-2.6.18-rc6-mm2/fs/autofs4/expire.c	2006-09-14 10:37:54.000000000 +0800
@@ -32,7 +32,7 @@ static inline int autofs4_can_expire(str
 
 	if (!do_now) {
 		/* Too young to die */
-		if (time_after(ino->last_used + timeout, now))
+		if (!timeout || time_after(ino->last_used + timeout, now))
 			return 0;
 
 		/* update last_used here :-
@@ -253,7 +253,7 @@ static struct dentry *autofs4_expire_dir
 	struct dentry *root = dget(sb->s_root);
 	int do_now = how & AUTOFS_EXP_IMMEDIATE;
 
-	if (!sbi->exp_timeout || !root)
+	if (!root)
 		return NULL;
 
 	now = jiffies;
@@ -293,7 +293,7 @@ static struct dentry *autofs4_expire_ind
 	int do_now = how & AUTOFS_EXP_IMMEDIATE;
 	int exp_leaves = how & AUTOFS_EXP_LEAVES;
 
-	if ( !sbi->exp_timeout || !root )
+	if (!root)
 		return NULL;
 
 	now = jiffies;

Re: [PATCH] autofs4 - zero timeout prevents shutdown

[Andrew Morton]

On Tue, 19 Sep 2006 11:48:15 +0800 (WST)
Ian Kent <raven@themaw.net> wrote:

> If the timeout of an autofs mount is set to zero then umounts
> are disabled. This works fine, however the kernel module checks
> the expire timeout and goes no further if it is zero. This is
> not the right thing to do at shutdown as the module is passed
> an option to expire mounts regardless of their timeout setting.

Is this a new feature, or a regression since <when>?

Thanks.

Re: [PATCH] autofs4 - zero timeout prevents shutdown

[Ian Kent]

On Mon, 2006-09-18 at 21:11 -0700, Andrew Morton wrote:
> On Tue, 19 Sep 2006 11:48:15 +0800 (WST)
> Ian Kent <raven@themaw.net> wrote:
> 
> > If the timeout of an autofs mount is set to zero then umounts
> > are disabled. This works fine, however the kernel module checks
> > the expire timeout and goes no further if it is zero. This is
> > not the right thing to do at shutdown as the module is passed
> > an option to expire mounts regardless of their timeout setting.
> 
> Is this a new feature, or a regression since <when>?

It's a regression which I must have introduced a long time ago. I can go
back and check the kernels if you'd like more specific info.

It should work this way and a recent report alerted me to it.

Ian

Re: [PATCH] autofs4 - zero timeout prevents shutdown

[Andrew Morton]

On Tue, 19 Sep 2006 12:33:52 +0800
Ian Kent <raven@themaw.net> wrote:

> On Mon, 2006-09-18 at 21:11 -0700, Andrew Morton wrote:
> > On Tue, 19 Sep 2006 11:48:15 +0800 (WST)
> > Ian Kent <raven@themaw.net> wrote:
> > 
> > > If the timeout of an autofs mount is set to zero then umounts
> > > are disabled. This works fine, however the kernel module checks
> > > the expire timeout and goes no further if it is zero. This is
> > > not the right thing to do at shutdown as the module is passed
> > > an option to expire mounts regardless of their timeout setting.
> > 
> > Is this a new feature, or a regression since <when>?
> 
> It's a regression which I must have introduced a long time ago. I can go
> back and check the kernels if you'd like more specific info.
> 
> It should work this way and a recent report alerted me to it.
> 

Well..  I'm trying to work out if it's a 2.6.18 thing or whether we can
hold it over.

Re: [PATCH] autofs4 - zero timeout prevents shutdown

[Ian Kent]

On Mon, 2006-09-18 at 21:38 -0700, Andrew Morton wrote:
> On Tue, 19 Sep 2006 12:33:52 +0800
> Ian Kent <raven@themaw.net> wrote:
> 
> > On Mon, 2006-09-18 at 21:11 -0700, Andrew Morton wrote:
> > > On Tue, 19 Sep 2006 11:48:15 +0800 (WST)
> > > Ian Kent <raven@themaw.net> wrote:
> > > 
> > > > If the timeout of an autofs mount is set to zero then umounts
> > > > are disabled. This works fine, however the kernel module checks
> > > > the expire timeout and goes no further if it is zero. This is
> > > > not the right thing to do at shutdown as the module is passed
> > > > an option to expire mounts regardless of their timeout setting.
> > > 
> > > Is this a new feature, or a regression since <when>?
> > 
> > It's a regression which I must have introduced a long time ago. I can go
> > back and check the kernels if you'd like more specific info.
> > 
> > It should work this way and a recent report alerted me to it.
> > 
> 
> Well..  I'm trying to work out if it's a 2.6.18 thing or whether we can
> hold it over.

I had a quick look and it appears to be present as far back as 2002/06
in 2.4. I'm a bit puzzled why I haven't seen it before as I'm sure I've
tested this over the years, never the less it looks so clearly wrong to
me know.

It's a bug fix and given it's been around so long, not a widely used.

Personally I'd like to get it into 2.6.18.
As always I'm happy with whatever decision you make.

Ian