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From: Signal9 <signal9@gmx.net>
To: Alexander Viro <viro@math.psu.edu>
Subject: Re: possible bug in VFS ?
Date: Sat, 13 Oct 2001 12:32:15 +0000
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On Saturday 13 October 2001 00:06, you wrote:
> On Sat, 13 Oct 2001, Signal9 wrote:
> >                root = current->fs->rootmnt;
> >                list_for_each(ptr, &root->mnt_list) {
> >                         mnt = list_entry(ptr, struct vfsmount, mnt_list);
> >                         sb = mnt ? mnt->mnt_sb : NULL;
> >                          if (NULL != sb && dev == sb->s_dev)
> > <============ mntget(mnt);
> >                 }
>
> 	What the hell is it trying to do?

 Here goes the complete function:
static 
int bc_lock_dev(struct bc_disk *bd, struct bc_device *bc, kdev_t dev, 
		int lock)
{
        struct super_block *sb;
        struct vfsmount    *mnt, *root;
        struct list_head   *ptr;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (!bd->bd_flags.configured) {
                if (!lock)
                        return 0;
                printk(KERN_ERR "bc: attempt to lock free device.\n");
                return -ENXIO;
        }

        if (lock && !bd->bd_flags.mounted) {
                root = current->fs->rootmnt;            
                list_for_each(ptr, &root->mnt_list) {
                        mnt = list_entry(ptr, struct vfsmount, mnt_list);
                        sb = mnt ? mnt->mnt_sb : NULL;
             
	           printk (KERN_WARNING "\n\n[++++] The pointer to sb is: %08x\nAnd 
the name is: %s\n\n",
                                        sb, mnt->mnt_devname);
             
	           if (NULL != sb && dev == sb->s_dev) 
                                        mntget(mnt);
                }
                bd->bd_flags.mounted = 1;
                bc->bc_refcnt++;
        } else if (!lock && bd->bd_flags.mounted) {
                root = current->fs->rootmnt;            
                list_for_each(ptr, &root->mnt_list) {
                        mnt = list_entry(ptr, struct vfsmount, mnt_list);
                        sb = mnt ? mnt->mnt_sb : NULL;

                        if (NULL != sb && dev == sb->s_dev)
                                        mntget(mnt);
                }
                bd->bd_flags.mounted = 0;
                bc->bc_refcnt--;
       }
        return 0;
}