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Revision fff1662cc423be00c5a7dffc6cf2332161c882d6 authored by Tobias Klauser on 04 September 2020, 23:35:46 UTC, committed by Linus Torvalds on 05 September 2020, 19:14:29 UTC 
ipc: adjust proc_ipc_sem_dointvec definition to match prototype
 
Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer.  Adjust the
signature of proc_ipc_sem_dointvec to match ctl_table.proc_handler which
fixes the following sparse error/warning:

  ipc/ipc_sysctl.c:94:47: warning: incorrect type in argument 3 (different address spaces)
  ipc/ipc_sysctl.c:94:47:    expected void *buffer
  ipc/ipc_sysctl.c:94:47:    got void [noderef] __user *buffer
  ipc/ipc_sysctl.c:194:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
  ipc/ipc_sysctl.c:194:35:    expected int ( [usertype] *proc_handler )( ... )
  ipc/ipc_sysctl.c:194:35:    got int ( * )( ... )

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200825105846.5193-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent e80d390
Raw File
fs_pin.c 
// SPDX-License-Identifier: GPL-2.0
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "internal.h"
#include "mount.h"

static DEFINE_SPINLOCK(pin_lock);

void pin_remove(struct fs_pin *pin)
{
	spin_lock(&pin_lock);
	hlist_del_init(&pin->m_list);
	hlist_del_init(&pin->s_list);
	spin_unlock(&pin_lock);
	spin_lock_irq(&pin->wait.lock);
	pin->done = 1;
	wake_up_locked(&pin->wait);
	spin_unlock_irq(&pin->wait.lock);
}

void pin_insert(struct fs_pin *pin, struct vfsmount *m)
{
	spin_lock(&pin_lock);
	hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
	hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
	spin_unlock(&pin_lock);
}

void pin_kill(struct fs_pin *p)
{
	wait_queue_entry_t wait;

	if (!p) {
		rcu_read_unlock();
		return;
	}
	init_wait(&wait);
	spin_lock_irq(&p->wait.lock);
	if (likely(!p->done)) {
		p->done = -1;
		spin_unlock_irq(&p->wait.lock);
		rcu_read_unlock();
		p->kill(p);
		return;
	}
	if (p->done > 0) {
		spin_unlock_irq(&p->wait.lock);
		rcu_read_unlock();
		return;
	}
	__add_wait_queue(&p->wait, &wait);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		spin_unlock_irq(&p->wait.lock);
		rcu_read_unlock();
		schedule();
		rcu_read_lock();
		if (likely(list_empty(&wait.entry)))
			break;
		/* OK, we know p couldn't have been freed yet */
		spin_lock_irq(&p->wait.lock);
		if (p->done > 0) {
			spin_unlock_irq(&p->wait.lock);
			break;
		}
	}
	rcu_read_unlock();
}

void mnt_pin_kill(struct mount *m)
{
	while (1) {
		struct hlist_node *p;
		rcu_read_lock();
		p = READ_ONCE(m->mnt_pins.first);
		if (!p) {
			rcu_read_unlock();
			break;
		}
		pin_kill(hlist_entry(p, struct fs_pin, m_list));
	}
}

void group_pin_kill(struct hlist_head *p)
{
	while (1) {
		struct hlist_node *q;
		rcu_read_lock();
		q = READ_ONCE(p->first);
		if (!q) {
			rcu_read_unlock();
			break;
		}
		pin_kill(hlist_entry(q, struct fs_pin, s_list));
	}
}
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