The prosthetic imagination

struct kstatfs sbuf;
int res;
int act;
sector_t resume;
sector_t suspend;

spin_lock(&acct_globals.lock);
res = acct_globals.active;
if (!file || !acct_globals.needcheck)
    goto out;
spin_unlock(&acct_globals.lock);

/* May block */
if (vfs_statfs(file->f_dentry, &sbuf))
    return res;
suspend = sbuf.f_blocks * SUSPEND;
resume = sbuf.f_blocks * RESUME;

sector_div(suspend, 100);
sector_div(resume, 100);

if (sbuf.f_bavail <= suspend)
    act = -1;
else if (sbuf.f_bavail >= resume)
    act = 1;
else
    act = 0;

/*
* If some joker switched acct_globals.file under
* us we'ld better be
* silent and _not_ touch anything.
*/
spin_lock(&acct_globals.lock);
if (file != acct_globals.file) {
     if (act)
          res = act>0;
     goto out;
}

if (acct_globals.active) {
     if (act < active =" 0;"> 0) {
         acct_globals.active = 1;
     printk(KERN_INFO "Process accounting resumed\n");
     }
}

del_timer(&acct_globals.timer);
acct_globals.needcheck = 0;
acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
add_timer(&acct_globals.timer);
res = acct_globals.active;
out:
spin_unlock(&acct_globals.lock);
return res;