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97 lines
1.9 KiB
97 lines
1.9 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/fs.h> |
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#include <linux/sched.h> |
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#include <linux/slab.h> |
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#include "internal.h" |
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#include "mount.h" |
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static DEFINE_SPINLOCK(pin_lock); |
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void pin_remove(struct fs_pin *pin) |
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{ |
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spin_lock(&pin_lock); |
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hlist_del_init(&pin->m_list); |
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hlist_del_init(&pin->s_list); |
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spin_unlock(&pin_lock); |
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spin_lock_irq(&pin->wait.lock); |
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pin->done = 1; |
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wake_up_locked(&pin->wait); |
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spin_unlock_irq(&pin->wait.lock); |
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} |
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void pin_insert(struct fs_pin *pin, struct vfsmount *m) |
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{ |
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spin_lock(&pin_lock); |
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hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins); |
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hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins); |
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spin_unlock(&pin_lock); |
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} |
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void pin_kill(struct fs_pin *p) |
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{ |
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wait_queue_entry_t wait; |
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if (!p) { |
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rcu_read_unlock(); |
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return; |
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} |
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init_wait(&wait); |
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spin_lock_irq(&p->wait.lock); |
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if (likely(!p->done)) { |
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p->done = -1; |
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spin_unlock_irq(&p->wait.lock); |
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rcu_read_unlock(); |
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p->kill(p); |
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return; |
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} |
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if (p->done > 0) { |
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spin_unlock_irq(&p->wait.lock); |
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rcu_read_unlock(); |
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return; |
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} |
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__add_wait_queue(&p->wait, &wait); |
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while (1) { |
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set_current_state(TASK_UNINTERRUPTIBLE); |
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spin_unlock_irq(&p->wait.lock); |
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rcu_read_unlock(); |
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schedule(); |
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rcu_read_lock(); |
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if (likely(list_empty(&wait.entry))) |
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break; |
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/* OK, we know p couldn't have been freed yet */ |
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spin_lock_irq(&p->wait.lock); |
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if (p->done > 0) { |
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spin_unlock_irq(&p->wait.lock); |
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break; |
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} |
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} |
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rcu_read_unlock(); |
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} |
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void mnt_pin_kill(struct mount *m) |
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{ |
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while (1) { |
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struct hlist_node *p; |
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rcu_read_lock(); |
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p = READ_ONCE(m->mnt_pins.first); |
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if (!p) { |
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rcu_read_unlock(); |
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break; |
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} |
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pin_kill(hlist_entry(p, struct fs_pin, m_list)); |
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} |
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} |
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void group_pin_kill(struct hlist_head *p) |
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{ |
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while (1) { |
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struct hlist_node *q; |
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rcu_read_lock(); |
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q = READ_ONCE(p->first); |
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if (!q) { |
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rcu_read_unlock(); |
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break; |
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} |
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pin_kill(hlist_entry(q, struct fs_pin, s_list)); |
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} |
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}
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