bsdacct: make internal code work with passed bsd_acct_struct, not global

This adds the appropriate pointer to all the internal (i.e. static)
functions that work with global acct instance. API calls pass a global
instance to them (while we still have such).

Mostly this is a s/acct_globals./acct->/ over the file.

Signed-off-by: Pavel Emelyanov <[e-mail]>
Cc: Balbir Singh <[e-mail]>
Cc: "Eric W. Biederman" <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

kernel/acct.c

···
 /*
  * External references and all of the globals.
  */
-static void do_acct_process(struct pid_namespace *ns, struct file *);
+static void do_acct_process(struct bsd_acct_struct *acct,
+		struct pid_namespace *ns, struct file *);
 
 /*
  * This structure is used so that all the data protected by lock
···
 /*
  * Check the amount of free space and suspend/resume accordingly.
  */
-static int check_free_space(struct file *file)
+static int check_free_space(struct bsd_acct_struct *acct, struct file *file)
 {
 	struct kstatfs sbuf;
 	int res;
···
 	sector_t suspend;
 
 	spin_lock(&acct_lock);
-	res = acct_globals.active;
-	if (!file || !acct_globals.needcheck)
+	res = acct->active;
+	if (!file || !acct->needcheck)
 		goto out;
 	spin_unlock(&acct_lock);
 
···
 		act = 0;
 
 	/*
-	 * If some joker switched acct_globals.file under us we'ld better be
+	 * If some joker switched acct->file under us we'ld better be
 	 * silent and _not_ touch anything.
 	 */
 	spin_lock(&acct_lock);
-	if (file != acct_globals.file) {
+	if (file != acct->file) {
 		if (act)
 			res = act>0;
 		goto out;
 	}
 
-	if (acct_globals.active) {
+	if (acct->active) {
 		if (act < 0) {
-			acct_globals.active = 0;
+			acct->active = 0;
 			printk(KERN_INFO "Process accounting paused\n");
 		}
 	} else {
 		if (act > 0) {
-			acct_globals.active = 1;
+			acct->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;
+	del_timer(&acct->timer);
+	acct->needcheck = 0;
+	acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ;
+	add_timer(&acct->timer);
+	res = acct->active;
 out:
 	spin_unlock(&acct_lock);
 	return res;
···
  *
  * NOTE: acct_lock MUST be held on entry and exit.
  */
-static void acct_file_reopen(struct file *file)
+static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file)
 {
 	struct file *old_acct = NULL;
 	struct pid_namespace *old_ns = NULL;
 
-	if (acct_globals.file) {
-		old_acct = acct_globals.file;
-		old_ns = acct_globals.ns;
-		del_timer(&acct_globals.timer);
-		acct_globals.active = 0;
-		acct_globals.needcheck = 0;
-		acct_globals.file = NULL;
+	if (acct->file) {
+		old_acct = acct->file;
+		old_ns = acct->ns;
+		del_timer(&acct->timer);
+		acct->active = 0;
+		acct->needcheck = 0;
+		acct->file = NULL;
 	}
 	if (file) {
-		acct_globals.file = file;
-		acct_globals.ns = get_pid_ns(task_active_pid_ns(current));
-		acct_globals.needcheck = 0;
-		acct_globals.active = 1;
+		acct->file = file;
+		acct->ns = get_pid_ns(task_active_pid_ns(current));
+		acct->needcheck = 0;
+		acct->active = 1;
 		/* It's been deleted if it was used before so this is safe */
-		setup_timer(&acct_globals.timer, acct_timeout,
-				(unsigned long)&acct_globals);
-		acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
-		add_timer(&acct_globals.timer);
+		setup_timer(&acct->timer, acct_timeout, (unsigned long)acct);
+		acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ;
+		add_timer(&acct->timer);
 	}
 	if (old_acct) {
 		mnt_unpin(old_acct->f_path.mnt);
 		spin_unlock(&acct_lock);
-		do_acct_process(old_ns, old_acct);
+		do_acct_process(acct, old_ns, old_acct);
 		filp_close(old_acct, NULL);
 		put_pid_ns(old_ns);
 		spin_lock(&acct_lock);
···
 
 	spin_lock(&acct_lock);
 	mnt_pin(file->f_path.mnt);
-	acct_file_reopen(file);
+	acct_file_reopen(&acct_globals, file);
 	spin_unlock(&acct_lock);
 
 	mntput(file->f_path.mnt); /* it's pinned, now give up active reference */
···
 		error = security_acct(NULL);
 		if (!error) {
 			spin_lock(&acct_lock);
-			acct_file_reopen(NULL);
+			acct_file_reopen(&acct_globals, NULL);
 			spin_unlock(&acct_lock);
 		}
 	}
···
 {
 	spin_lock(&acct_lock);
 	if (acct_globals.file && acct_globals.file->f_path.mnt == m)
-		acct_file_reopen(NULL);
+		acct_file_reopen(&acct_globals, NULL);
 	spin_unlock(&acct_lock);
 }
 
···
 	spin_lock(&acct_lock);
 	if (acct_globals.file &&
 	    acct_globals.file->f_path.mnt->mnt_sb == sb) {
-		acct_file_reopen(NULL);
+		acct_file_reopen(&acct_globals, NULL);
 	}
 	spin_unlock(&acct_lock);
 }
···
 /*
  *  do_acct_process does all actual work. Caller holds the reference to file.
  */
-static void do_acct_process(struct pid_namespace *ns, struct file *file)
+static void do_acct_process(struct bsd_acct_struct *acct,
+		struct pid_namespace *ns, struct file *file)
 {
 	struct pacct_struct *pacct = &current->signal->pacct;
 	acct_t ac;
···
 	 * First check to see if there is enough free_space to continue
 	 * the process accounting system.
 	 */
-	if (!check_free_space(file))
+	if (!check_free_space(acct, file))
 		return;
 
 	/*
···
 	ns = get_pid_ns(acct_globals.ns);
 	spin_unlock(&acct_lock);
 
-	do_acct_process(ns, file);
+	do_acct_process(&acct_globals, ns, file);
 	fput(file);
 	put_pid_ns(ns);
 }