separate namespace-independent parts of filling acct_t

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kernel/acct.c

@@ -448,42 +448,20 @@ static u32 encode_float(u64 value)
  *  do_exit() or when switching to a different output file.
  */
 
-/*
- *  do_acct_process does all actual work. Caller holds the reference to file.
- */
-static void do_acct_process(struct bsd_acct_struct *acct,
-		struct pid_namespace *ns, struct file *file)
+static void fill_ac(acct_t *ac)
 {
 	struct pacct_struct *pacct = &current->signal->pacct;
-	acct_t ac;
-	unsigned long flim;
 	u64 elapsed, run_time;
 	struct tty_struct *tty;
-	const struct cred *orig_cred;
-
-	/*
-	 * Accounting records are not subject to resource limits.
-	 */
-	flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-	current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-	/* Perform file operations on behalf of whoever enabled accounting */
-	orig_cred = override_creds(file->f_cred);
-
-	/*
-	 * First check to see if there is enough free_space to continue
-	 * the process accounting system.
-	 */
-	if (!check_free_space(acct, file))
-		goto out;
 
 	/*
 	 * Fill the accounting struct with the needed info as recorded
 	 * by the different kernel functions.
 	 */
-	memset(&ac, 0, sizeof(acct_t));
+	memset(ac, 0, sizeof(acct_t));
 
-	ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER;
-	strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
+	ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER;
+	strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm));
 
 	/* calculate run_time in nsec*/
 	run_time = ktime_get_ns();
@@ -491,27 +469,66 @@ static void do_acct_process(struct bsd_acct_struct *acct,
 	/* convert nsec -> AHZ */
 	elapsed = nsec_to_AHZ(run_time);
 #if ACCT_VERSION==3
-	ac.ac_etime = encode_float(elapsed);
+	ac->ac_etime = encode_float(elapsed);
 #else
-	ac.ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
+	ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
 	                       (unsigned long) elapsed : (unsigned long) -1l);
 #endif
 #if ACCT_VERSION==1 || ACCT_VERSION==2
 	{
 		/* new enlarged etime field */
 		comp2_t etime = encode_comp2_t(elapsed);
-		ac.ac_etime_hi = etime >> 16;
-		ac.ac_etime_lo = (u16) etime;
+		ac->ac_etime_hi = etime >> 16;
+		ac->ac_etime_lo = (u16) etime;
 	}
 #endif
 	do_div(elapsed, AHZ);
-	ac.ac_btime = get_seconds() - elapsed;
+	ac->ac_btime = get_seconds() - elapsed;
+#if ACCT_VERSION==2
+	ac->ac_ahz = AHZ;
+#endif
+
+	spin_lock_irq(&current->sighand->siglock);
+	tty = current->signal->tty;	/* Safe as we hold the siglock */
+	ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
+	ac->ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
+	ac->ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
+	ac->ac_flag = pacct->ac_flag;
+	ac->ac_mem = encode_comp_t(pacct->ac_mem);
+	ac->ac_minflt = encode_comp_t(pacct->ac_minflt);
+	ac->ac_majflt = encode_comp_t(pacct->ac_majflt);
+	ac->ac_exitcode = pacct->ac_exitcode;
+	spin_unlock_irq(&current->sighand->siglock);
+}
+/*
+ *  do_acct_process does all actual work. Caller holds the reference to file.
+ */
+static void do_acct_process(struct bsd_acct_struct *acct,
+		struct pid_namespace *ns, struct file *file)
+{
+	acct_t ac;
+	unsigned long flim;
+	const struct cred *orig_cred;
+
+	/*
+	 * Accounting records are not subject to resource limits.
+	 */
+	flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+	current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
+	/* Perform file operations on behalf of whoever enabled accounting */
+	orig_cred = override_creds(file->f_cred);
+
+	/*
+	 * First check to see if there is enough free_space to continue
+	 * the process accounting system.
+	 */
+	if (!check_free_space(acct, file))
+		goto out;
+
+	fill_ac(&ac);
 	/* we really need to bite the bullet and change layout */
 	ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid);
 	ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid);
-#if ACCT_VERSION==2
-	ac.ac_ahz = AHZ;
-#endif
 #if ACCT_VERSION==1 || ACCT_VERSION==2
 	/* backward-compatible 16 bit fields */
 	ac.ac_uid16 = ac.ac_uid;
@@ -523,19 +540,6 @@ static void do_acct_process(struct bsd_acct_struct *acct,
 	ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);
 	rcu_read_unlock();
 #endif
-
-	spin_lock_irq(&current->sighand->siglock);
-	tty = current->signal->tty;	/* Safe as we hold the siglock */
-	ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
-	ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
-	ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
-	ac.ac_flag = pacct->ac_flag;
-	ac.ac_mem = encode_comp_t(pacct->ac_mem);
-	ac.ac_minflt = encode_comp_t(pacct->ac_minflt);
-	ac.ac_majflt = encode_comp_t(pacct->ac_majflt);
-	ac.ac_exitcode = pacct->ac_exitcode;
-	spin_unlock_irq(&current->sighand->siglock);
-
 	/*
 	 * Get freeze protection. If the fs is frozen, just skip the write
 	 * as we could deadlock the system otherwise.