diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2015-01-10 17:53:21 -0500 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-01-25 23:17:28 -0500 |
commit | 59eda0e07f43c950d31756213b607af673e551f0 (patch) | |
tree | f40f7b67133576c36a65a4cba9aca5df68d00f34 /fs | |
parent | fdab684d7202774bfd8762d4a656a553b787c8ec (diff) | |
download | linux-stable-59eda0e07f43c950d31756213b607af673e551f0.tar.gz linux-stable-59eda0e07f43c950d31756213b607af673e551f0.tar.bz2 linux-stable-59eda0e07f43c950d31756213b607af673e551f0.zip |
new fs_pin killing logics
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/fs_pin.c | 54 |
1 files changed, 48 insertions, 6 deletions
diff --git a/fs/fs_pin.c b/fs/fs_pin.c index 50ef7d2ef03c..0c77bdc238b2 100644 --- a/fs/fs_pin.c +++ b/fs/fs_pin.c @@ -1,4 +1,5 @@ #include <linux/fs.h> +#include <linux/sched.h> #include <linux/slab.h> #include <linux/fs_pin.h> #include "internal.h" @@ -12,6 +13,10 @@ void pin_remove(struct fs_pin *pin) hlist_del(&pin->m_list); hlist_del(&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_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p) @@ -28,19 +33,58 @@ void pin_insert(struct fs_pin *pin, struct vfsmount *m) pin_insert_group(pin, m, &m->mnt_sb->s_pins); } +void pin_kill(struct fs_pin *p) +{ + wait_queue_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.task_list))) + 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; - struct fs_pin *pin; rcu_read_lock(); p = ACCESS_ONCE(m->mnt_pins.first); if (!p) { rcu_read_unlock(); break; } - pin = hlist_entry(p, struct fs_pin, m_list); - pin->kill(pin); + pin_kill(hlist_entry(p, struct fs_pin, m_list)); } } @@ -48,14 +92,12 @@ void group_pin_kill(struct hlist_head *p) { while (1) { struct hlist_node *q; - struct fs_pin *pin; rcu_read_lock(); q = ACCESS_ONCE(p->first); if (!q) { rcu_read_unlock(); break; } - pin = hlist_entry(q, struct fs_pin, s_list); - pin->kill(pin); + pin_kill(hlist_entry(q, struct fs_pin, s_list)); } } |