pid namespaces: round up the API

The set of functions process_session, task_session, process_group and
task_pgrp is confusing, as the names can be mixed with each other when looking
at the code for a long time.

The proposals are to
* equip the functions that return the integer with _nr suffix to
  represent that fact,
* and to make all functions work with task (not process) by making
  the common prefix of the same name.

For monotony the routines signal_session() and set_signal_session() are
replaced with task_session_nr() and set_task_session(), especially since they
are only used with the explicit task->signal dereference.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/kernel/irixelf.c

@@ -1172,8 +1172,8 @@ static int irix_core_dump(long signr, struct pt_regs *regs, struct file *file, u
 	prstatus.pr_sighold = current->blocked.sig[0];
 	psinfo.pr_pid = prstatus.pr_pid = current->pid;
 	psinfo.pr_ppid = prstatus.pr_ppid = current->parent->pid;
-	psinfo.pr_pgrp = prstatus.pr_pgrp = process_group(current);
-	psinfo.pr_sid = prstatus.pr_sid = process_session(current);
+	psinfo.pr_pgrp = prstatus.pr_pgrp = task_pgrp_nr(current);
+	psinfo.pr_sid = prstatus.pr_sid = task_session_nr(current);
 	if (current->pid == current->tgid) {
 		/*
 		 * This is the record for the group leader.  Add in the

arch/mips/kernel/irixsig.c

@@ -609,7 +609,7 @@ repeat:
 		p = list_entry(_p, struct task_struct, sibling);
 		if ((type == IRIX_P_PID) && p->pid != pid)
 			continue;
-		if ((type == IRIX_P_PGID) && process_group(p) != pid)
+		if ((type == IRIX_P_PGID) && task_pgrp_nr(p) != pid)
 			continue;
 		if ((p->exit_signal != SIGCHLD))
 			continue;

arch/mips/kernel/sysirix.c

@@ -763,11 +763,11 @@ asmlinkage int irix_setpgrp(int flags)
 	printk("[%s:%d] setpgrp(%d) ", current->comm, current->pid, flags);
 #endif
 	if(!flags)
-		error = process_group(current);
+		error = task_pgrp_nr(current);
 	else
 		error = sys_setsid();
 #ifdef DEBUG_PROCGRPS
-	printk("returning %d\n", process_group(current));
+	printk("returning %d\n", task_pgrp_nr(current));
 #endif
 
 	return error;

arch/sparc64/solaris/misc.c

@@ -415,7 +415,7 @@ asmlinkage int solaris_procids(int cmd, s32 pid, s32 pgid)
 	
 	switch (cmd) {
 	case 0: /* getpgrp */
-		return process_group(current);
+		return task_pgrp_nr(current);
 	case 1: /* setpgrp */
 		{
 			int (*sys_setpgid)(pid_t,pid_t) =
@@ -426,7 +426,7 @@ asmlinkage int solaris_procids(int cmd, s32 pid, s32 pgid)
 			ret = sys_setpgid(0, 0);
 			if (ret) return ret;
 			proc_clear_tty(current);
-			return process_group(current);
+			return task_pgrp_nr(current);
 		}
 	case 2: /* getsid */
 		{

drivers/char/tty_io.c

@@ -3528,7 +3528,7 @@ void __do_SAK(struct tty_struct *tty)
 	/* Kill the entire session */
 	do_each_pid_task(session, PIDTYPE_SID, p) {
 		printk(KERN_NOTICE "SAK: killed process %d"
-			" (%s): process_session(p)==tty->session\n",
+			" (%s): task_session_nr(p)==tty->session\n",
 			p->pid, p->comm);
 		send_sig(SIGKILL, p, 1);
 	} while_each_pid_task(session, PIDTYPE_SID, p);
@@ -3538,7 +3538,7 @@ void __do_SAK(struct tty_struct *tty)
 	do_each_thread(g, p) {
 		if (p->signal->tty == tty) {
 			printk(KERN_NOTICE "SAK: killed process %d"
-			    " (%s): process_session(p)==tty->session\n",
+			    " (%s): task_session_nr(p)==tty->session\n",
 			    p->pid, p->comm);
 			send_sig(SIGKILL, p, 1);
 			continue;

fs/autofs/inode.c

@@ -80,7 +80,7 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
 
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = process_group(current);
+	*pgrp = task_pgrp_nr(current);
 
 	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
 

fs/autofs/root.c

@@ -215,7 +215,7 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr
 	oz_mode = autofs_oz_mode(sbi);
 	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
 				"oz_mode = %d\n", pid_nr(task_pid(current)),
-				process_group(current), sbi->catatonic,
+				task_pgrp_nr(current), sbi->catatonic,
 				oz_mode));
 
 	/*
@@ -536,7 +536,7 @@ static int autofs_root_ioctl(struct inode *inode, struct file *filp,
 	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
 	void __user *argp = (void __user *)arg;
 
-	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,process_group(current)));
+	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
 
 	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)

fs/autofs4/autofs_i.h

@@ -131,7 +131,7 @@ static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
    filesystem without "magic".) */
 
 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
-	return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
+	return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
 }
 
 /* Does a dentry have some pending activity? */

fs/autofs4/inode.c

@@ -226,7 +226,7 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
 
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = process_group(current);
+	*pgrp = task_pgrp_nr(current);
 
 	*minproto = AUTOFS_MIN_PROTO_VERSION;
 	*maxproto = AUTOFS_MAX_PROTO_VERSION;
@@ -323,7 +323,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 	sbi->pipe = NULL;
 	sbi->catatonic = 1;
 	sbi->exp_timeout = 0;
-	sbi->oz_pgrp = process_group(current);
+	sbi->oz_pgrp = task_pgrp_nr(current);
 	sbi->sb = s;
 	sbi->version = 0;
 	sbi->sub_version = 0;

fs/autofs4/root.c

@@ -582,7 +582,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
 	oz_mode = autofs4_oz_mode(sbi);
 
 	DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
-		 current->pid, process_group(current), sbi->catatonic, oz_mode);
+		 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
 
 	unhashed = autofs4_lookup_unhashed(sbi, dentry->d_parent, &dentry->d_name);
 	if (!unhashed) {
@@ -976,7 +976,7 @@ static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
 	void __user *p = (void __user *)arg;
 
 	DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
-		cmd,arg,sbi,process_group(current));
+		cmd,arg,sbi,task_pgrp_nr(current));
 
 	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)

fs/binfmt_elf.c

@@ -1385,8 +1385,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 	prstatus->pr_sighold = p->blocked.sig[0];
 	prstatus->pr_pid = p->pid;
 	prstatus->pr_ppid = p->parent->pid;
-	prstatus->pr_pgrp = process_group(p);
-	prstatus->pr_sid = process_session(p);
+	prstatus->pr_pgrp = task_pgrp_nr(p);
+	prstatus->pr_sid = task_session_nr(p);
 	if (thread_group_leader(p)) {
 		/*
 		 * This is the record for the group leader.  Add in the
@@ -1431,8 +1431,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
 
 	psinfo->pr_pid = p->pid;
 	psinfo->pr_ppid = p->parent->pid;
-	psinfo->pr_pgrp = process_group(p);
-	psinfo->pr_sid = process_session(p);
+	psinfo->pr_pgrp = task_pgrp_nr(p);
+	psinfo->pr_sid = task_session_nr(p);
 
 	i = p->state ? ffz(~p->state) + 1 : 0;
 	psinfo->pr_state = i;

fs/binfmt_elf_fdpic.c

@@ -1344,8 +1344,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 	prstatus->pr_sighold = p->blocked.sig[0];
 	prstatus->pr_pid = p->pid;
 	prstatus->pr_ppid = p->parent->pid;
-	prstatus->pr_pgrp = process_group(p);
-	prstatus->pr_sid = process_session(p);
+	prstatus->pr_pgrp = task_pgrp_nr(p);
+	prstatus->pr_sid = task_session_nr(p);
 	if (thread_group_leader(p)) {
 		/*
 		 * This is the record for the group leader.  Add in the
@@ -1393,8 +1393,8 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
 
 	psinfo->pr_pid = p->pid;
 	psinfo->pr_ppid = p->parent->pid;
-	psinfo->pr_pgrp = process_group(p);
-	psinfo->pr_sid = process_session(p);
+	psinfo->pr_pgrp = task_pgrp_nr(p);
+	psinfo->pr_sid = task_session_nr(p);
 
 	i = p->state ? ffz(~p->state) + 1 : 0;
 	psinfo->pr_state = i;

fs/coda/upcall.c

@@ -51,7 +51,7 @@ static void *alloc_upcall(int opcode, int size)
 
         inp->ih.opcode = opcode;
 	inp->ih.pid = current->pid;
-	inp->ih.pgid = process_group(current);
+	inp->ih.pgid = task_pgrp_nr(current);
 #ifdef CONFIG_CODA_FS_OLD_API
 	memset(&inp->ih.cred, 0, sizeof(struct coda_cred));
 	inp->ih.cred.cr_fsuid = current->fsuid;

fs/proc/array.c

@@ -449,8 +449,8 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
 			gtime += cputime_add(gtime, sig->gtime);
 		}
 
-		sid = signal_session(sig);
-		pgid = process_group(task);
+		sid = task_session_nr(task);
+		pgid = task_pgrp_nr(task);
 		ppid = rcu_dereference(task->real_parent)->tgid;
 
 		unlock_task_sighand(task, &flags);

include/linux/sched.h

@@ -1188,24 +1188,19 @@ static inline int rt_task(struct task_struct *p)
 	return rt_prio(p->prio);
 }
 
-static inline pid_t process_group(struct task_struct *tsk)
+static inline pid_t task_pgrp_nr(struct task_struct *tsk)
 {
 	return tsk->signal->pgrp;
 }
 
-static inline pid_t signal_session(struct signal_struct *sig)
+static inline pid_t task_session_nr(struct task_struct *tsk)
 {
-	return sig->__session;
+	return tsk->signal->__session;
 }
 
-static inline pid_t process_session(struct task_struct *tsk)
+static inline void set_task_session(struct task_struct *tsk, pid_t session)
 {
-	return signal_session(tsk->signal);
-}
-
-static inline void set_signal_session(struct signal_struct *sig, pid_t session)
-{
-	sig->__session = session;
+	tsk->signal->__session = session;
 }
 
 static inline struct pid *task_pid(struct task_struct *task)

kernel/exit.c

@@ -299,12 +299,12 @@ void __set_special_pids(pid_t session, pid_t pgrp)
 {
 	struct task_struct *curr = current->group_leader;
 
-	if (process_session(curr) != session) {
+	if (task_session_nr(curr) != session) {
 		detach_pid(curr, PIDTYPE_SID);
-		set_signal_session(curr->signal, session);
+		set_task_session(curr, session);
 		attach_pid(curr, PIDTYPE_SID, find_pid(session));
 	}
-	if (process_group(curr) != pgrp) {
+	if (task_pgrp_nr(curr) != pgrp) {
 		detach_pid(curr, PIDTYPE_PGID);
 		curr->signal->pgrp = pgrp;
 		attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
@@ -1091,10 +1091,10 @@ static int eligible_child(pid_t pid, int options, struct task_struct *p)
 		if (p->pid != pid)
 			return 0;
 	} else if (!pid) {
-		if (process_group(p) != process_group(current))
+		if (task_pgrp_nr(p) != task_pgrp_nr(current))
 			return 0;
 	} else if (pid != -1) {
-		if (process_group(p) != -pid)
+		if (task_pgrp_nr(p) != -pid)
 			return 0;
 	}
 

kernel/fork.c

@@ -1283,8 +1283,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 		if (thread_group_leader(p)) {
 			p->signal->tty = current->signal->tty;
-			p->signal->pgrp = process_group(current);
-			set_signal_session(p->signal, process_session(current));
+			p->signal->pgrp = task_pgrp_nr(current);
+			set_task_session(p, task_session_nr(current));
 			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
 			attach_pid(p, PIDTYPE_SID, task_session(current));
 

kernel/signal.c

@@ -536,7 +536,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 			return error;
 		error = -EPERM;
 		if (((sig != SIGCONT) ||
-			(process_session(current) != process_session(t)))
+			(task_session_nr(current) != task_session_nr(t)))
 		    && (current->euid ^ t->suid) && (current->euid ^ t->uid)
 		    && (current->uid ^ t->suid) && (current->uid ^ t->uid)
 		    && !capable(CAP_KILL))

kernel/sys.c

@@ -968,7 +968,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
 	if (err)
 		goto out;
 
-	if (process_group(p) != pgid) {
+	if (task_pgrp_nr(p) != pgid) {
 		detach_pid(p, PIDTYPE_PGID);
 		p->signal->pgrp = pgid;
 		attach_pid(p, PIDTYPE_PGID, find_pid(pgid));
@@ -984,7 +984,7 @@ out:
 asmlinkage long sys_getpgid(pid_t pid)
 {
 	if (!pid)
-		return process_group(current);
+		return task_pgrp_nr(current);
 	else {
 		int retval;
 		struct task_struct *p;
@@ -996,7 +996,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 		if (p) {
 			retval = security_task_getpgid(p);
 			if (!retval)
-				retval = process_group(p);
+				retval = task_pgrp_nr(p);
 		}
 		read_unlock(&tasklist_lock);
 		return retval;
@@ -1008,7 +1008,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 asmlinkage long sys_getpgrp(void)
 {
 	/* SMP - assuming writes are word atomic this is fine */
-	return process_group(current);
+	return task_pgrp_nr(current);
 }
 
 #endif
@@ -1016,7 +1016,7 @@ asmlinkage long sys_getpgrp(void)
 asmlinkage long sys_getsid(pid_t pid)
 {
 	if (!pid)
-		return process_session(current);
+		return task_session_nr(current);
 	else {
 		int retval;
 		struct task_struct *p;
@@ -1028,7 +1028,7 @@ asmlinkage long sys_getsid(pid_t pid)
 		if (p) {
 			retval = security_task_getsid(p);
 			if (!retval)
-				retval = process_session(p);
+				retval = task_session_nr(p);
 		}
 		read_unlock(&tasklist_lock);
 		return retval;
@@ -1065,7 +1065,7 @@ asmlinkage long sys_setsid(void)
 	group_leader->signal->tty = NULL;
 	spin_unlock(&group_leader->sighand->siglock);
 
-	err = process_group(group_leader);
+	err = task_pgrp_nr(group_leader);
 out:
 	write_unlock_irq(&tasklist_lock);
 	return err;