From: Dan Carpenter <dan.carpenter@oracle.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [bug report] ocfs2: fix value of OCFS2_INVALID_SLOT
Date: Wed, 24 Jun 2020 17:57:04 +0300 [thread overview]
Message-ID: <20200624145704.GA31008@kadam> (raw)
In-Reply-To: <83182084-7bb9-93bb-ee44-8cfd25315940@oracle.com>
On Tue, Jun 23, 2020 at 01:26:11PM -0700, Junxiao Bi wrote:
> On 6/23/20 4:05 AM, Dan Carpenter wrote:
>
> > Hello Junxiao Bi,
> >
> > The patch c824ce1feffa: "ocfs2: fix value of OCFS2_INVALID_SLOT" from
> > Jun 21, 2020, leads to the following static checker warning:
> >
> > fs/ocfs2/super.c:1269 ocfs2_parse_options()
> > warn: '(-1)' 65535 can't fit into 32767 'mopt->slot'
> >
> > fs/ocfs2/super.c
> > 1253 static int ocfs2_parse_options(struct super_block *sb,
> > 1254 char *options,
> > 1255 struct mount_options *mopt,
> > 1256 int is_remount)
> > 1257 {
> > 1258 int status, user_stack = 0;
> > 1259 char *p;
> > 1260 u32 tmp;
> > 1261 int token, option;
> > 1262 substring_t args[MAX_OPT_ARGS];
> > 1263
> > 1264 trace_ocfs2_parse_options(is_remount, options ? options : "(none)");
> > 1265
> > 1266 mopt->commit_interval = 0;
> > 1267 mopt->mount_opt = OCFS2_MOUNT_NOINTR;
> > 1268 mopt->atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
> > 1269 mopt->slot = OCFS2_INVALID_SLOT;
> > ^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^
> > OCFS2_INVALID_SLOT used to be -1, but the patch changed it to USHRT_MAX.
> > mopt->slot is a s16 so it becomes -1 again.
> > We assign it to osb->preferred_slot which is an int so it's still -1.
>
> hmm, i think osb->perferred_slot should be 65535, not -1. I test with the
> following small program.
>
> #include <stdlib.h>
> #include <stdio.h>
>
> int main(void)
> {
> ??? int i;
> ??? short s;
> ??? unsigned short us;
>
> ??? us = -1;
> ??? s = us;
> ??? i = s;
> ??? printf("i %d s %d us %d\n", i, s, us);
> }
I'm looking at linux-next. The only thing which is unsigend short is
the OCFS2_INVALID_SLOT define itself. The other variables are either
signed short or int. In this case what we care about is the
preferred_slot which is an int.
#define OCFS2_INVALID_SLOT ((unsigned short)-1)
int main(void)
{
short slot = OCFS2_INVALID_SLOT;
int perferred_slot = slot;
if (perferred_slot == OCFS2_INVALID_SLOT)
printf("Works\n");
else
printf("nope\n");
}
There are a few other place where the types cause an issue.
fs/ocfs2/super.c:1269 ocfs2_parse_options() warn: '(-1)' 65535 can't fit into 32767 'mopt->slot'
fs/ocfs2/suballoc.c:859 ocfs2_init_inode_steal_slot() warn: '(-1)' 65535 can't fit into 32767 'osb->s_inode_steal_slot'
fs/ocfs2/suballoc.c:867 ocfs2_init_meta_steal_slot() warn: '(-1)' 65535 can't fit into 32767 'osb->s_meta_steal_slot'
regards,
dan carpenter
prev parent reply other threads:[~2020-06-24 14:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 11:05 [Ocfs2-devel] [bug report] ocfs2: fix value of OCFS2_INVALID_SLOT Dan Carpenter
2020-06-23 20:26 ` Junxiao Bi
2020-06-24 14:57 ` Dan Carpenter [this message]
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