VisionFive2 Linux kernel

b24413180f560 (Greg Kroah-Hartman 2017-11-01 15:07:57 +0100  1) // SPDX-License-Identifier: GPL-2.0
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  2) #include <linux/fs.h>
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500  3) #include <linux/sched.h>
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  4) #include <linux/slab.h>
8fa1f1c2bd860 (Al Viro            2014-05-21 18:22:52 -0400  5) #include "internal.h"
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  6) #include "mount.h"
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  7) 
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  8) static DEFINE_SPINLOCK(pin_lock);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400  9) 
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 10) void pin_remove(struct fs_pin *pin)
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 11) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 12) 	spin_lock(&pin_lock);
820f9f147dcce (Eric W. Biederman  2015-04-02 16:35:48 -0500 13) 	hlist_del_init(&pin->m_list);
820f9f147dcce (Eric W. Biederman  2015-04-02 16:35:48 -0500 14) 	hlist_del_init(&pin->s_list);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 15) 	spin_unlock(&pin_lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 16) 	spin_lock_irq(&pin->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 17) 	pin->done = 1;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 18) 	wake_up_locked(&pin->wait);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 19) 	spin_unlock_irq(&pin->wait.lock);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 20) }
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 21) 
56cbb429d9119 (Al Viro            2019-07-04 16:57:51 -0400 22) void pin_insert(struct fs_pin *pin, struct vfsmount *m)
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 23) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 24) 	spin_lock(&pin_lock);
56cbb429d9119 (Al Viro            2019-07-04 16:57:51 -0400 25) 	hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 26) 	hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 27) 	spin_unlock(&pin_lock);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 28) }
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 29) 
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 30) void pin_kill(struct fs_pin *p)
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 31) {
ac6424b981bce (Ingo Molnar        2017-06-20 12:06:13 +0200 32) 	wait_queue_entry_t wait;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 33) 
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 34) 	if (!p) {
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 35) 		rcu_read_unlock();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 36) 		return;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 37) 	}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 38) 	init_wait(&wait);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 39) 	spin_lock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 40) 	if (likely(!p->done)) {
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 41) 		p->done = -1;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 42) 		spin_unlock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 43) 		rcu_read_unlock();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 44) 		p->kill(p);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 45) 		return;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 46) 	}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 47) 	if (p->done > 0) {
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 48) 		spin_unlock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 49) 		rcu_read_unlock();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 50) 		return;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 51) 	}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 52) 	__add_wait_queue(&p->wait, &wait);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 53) 	while (1) {
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 54) 		set_current_state(TASK_UNINTERRUPTIBLE);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 55) 		spin_unlock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 56) 		rcu_read_unlock();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 57) 		schedule();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 58) 		rcu_read_lock();
2055da97389a6 (Ingo Molnar        2017-06-20 12:06:46 +0200 59) 		if (likely(list_empty(&wait.entry)))
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 60) 			break;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 61) 		/* OK, we know p couldn't have been freed yet */
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 62) 		spin_lock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 63) 		if (p->done > 0) {
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 64) 			spin_unlock_irq(&p->wait.lock);
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 65) 			break;
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 66) 		}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 67) 	}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 68) 	rcu_read_unlock();
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 69) }
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 70) 
8fa1f1c2bd860 (Al Viro            2014-05-21 18:22:52 -0400 71) void mnt_pin_kill(struct mount *m)
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 72) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 73) 	while (1) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 74) 		struct hlist_node *p;
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 75) 		rcu_read_lock();
6aa7de059173a (Mark Rutland       2017-10-23 14:07:29 -0700 76) 		p = READ_ONCE(m->mnt_pins.first);
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 77) 		if (!p) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 78) 			rcu_read_unlock();
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 79) 			break;
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 80) 		}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 81) 		pin_kill(hlist_entry(p, struct fs_pin, m_list));
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 82) 	}
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 83) }
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 84) 
fdab684d72027 (Al Viro            2015-01-11 10:57:27 -0500 85) void group_pin_kill(struct hlist_head *p)
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 86) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 87) 	while (1) {
fdab684d72027 (Al Viro            2015-01-11 10:57:27 -0500 88) 		struct hlist_node *q;
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 89) 		rcu_read_lock();
6aa7de059173a (Mark Rutland       2017-10-23 14:07:29 -0700 90) 		q = READ_ONCE(p->first);
fdab684d72027 (Al Viro            2015-01-11 10:57:27 -0500 91) 		if (!q) {
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 92) 			rcu_read_unlock();
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 93) 			break;
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 94) 		}
59eda0e07f43c (Al Viro            2015-01-10 17:53:21 -0500 95) 		pin_kill(hlist_entry(q, struct fs_pin, s_list));
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 96) 	}
efb170c22867c (Al Viro            2014-08-07 08:39:04 -0400 97) }