Re: [PATCH 14/16] GFS2: The DLM interface module

[Steven Whitehouse]

Hi,

On Tue, 2006-09-05 at 14:05 +0200, Jan Engelhardt wrote:
> >+/* make_strname - convert GFS lock numbers to a string */
> >+
> >+static inline void make_strname(struct lm_lockname *lockname,
> >+				struct gdlm_strname *str)
> >+{
> >+	sprintf(str->name, "%8x%16llx", lockname->ln_type,
> >+		(unsigned long long)lockname->ln_number);
> 
> Is this format specifier safe enough? "%08x%016llx" perhaps?
> 
> Imagine (if this happens at all):
> 
>   ln_type = 1; ln_number = 16;
>   %8x = "1", "%16llx" = "10", giving us "110"
> 
>   ln_type = 17; ln_number = 0;
>   %8x = "11", "%16llx" = "0", giving us "110".
> 
> Whoops, name clash.
> 
In this case the field sizes mean that the numbers are padded with
spaces. Also we "know" that ln_type will always be a single digit at
least with the current implementation.

[lines snipped]
> >+	op->info.owner		= (__u64)(long) fl->fl_owner;
> 
> Can't op->info.owner be a 'struct fowner *'? Is op->info.owner shared over the
> network?
> 
It is shared over the network.

> >+static ssize_t block_show(struct gdlm_ls *ls, char *buf)
> >+{
> >+	ssize_t ret;
> >+	int val = 0;
> >+
> >+	if (test_bit(DFL_BLOCK_LOCKS, &ls->flags))
> >+		val = 1;
> >+	ret = sprintf(buf, "%d\n", val);
> 
> Safe enough - @buf big enough?
> 
Yes, buf is one page in size. However Dave Teigland has sent me a couple
of patches to update these routines to the "best practice" according to
the docs for sysfs.

> >+	if (val == 1)
> >+		set_bit(DFL_BLOCK_LOCKS, &ls->flags);
> >+	else if (val == 0) {
> >+		clear_bit(DFL_BLOCK_LOCKS, &ls->flags);
> >+		gdlm_submit_delayed(ls);
> >+	} else
> >+		ret = -EINVAL;
> 
> Ingo surely wants you to {} it.
> 
I've fixed that now. This email's patches are:

http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=c53921248c79197befa7caa4c17b1af5c077a2c2
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=3204a6c05588788f7686bc45585185a9a4788430
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=a1d144c71ddc11d3e9d9f29e92cf037da382a541
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=62f140c173f2c85e15527eefc6e2fb3c37a97eb1

Steve.


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