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Message-ID: <47FDD48D.6070304@openvz.org>
Date: Thu, 10 Apr 2008 12:49:17 +0400
From: Pavel Emelyanov <xemul@...nvz.org>
To: Oleg Nesterov <oleg@...sign.ru>,
Sukadev Bhattiprolu <sukadev@...ibm.com>,
Alexey Dobriyan <adobriyan@...nvz.org>
CC: Linux Containers <containers@...ts.osdl.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 6/10] Bsdacct: make the acct_lock global
Don't use per-bsd-acct-struct lock, but work with a global
one. This lock is taken for short periods, so it's not going
to be a bottleneck, but it will allow us to easily avoid
many locking difficulties in the future.
Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>
---
kernel/acct.c | 42 +++++++++++++++++++++---------------------
1 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/kernel/acct.c b/kernel/acct.c
index 05f8bc0..fc71c13 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -83,7 +83,6 @@ static void do_acct_process(struct pid_namespace *ns, struct file *);
* the cache line to have the data after getting the lock.
*/
struct bsd_acct_struct {
- spinlock_t lock;
volatile int active;
volatile int needcheck;
struct file *file;
@@ -91,8 +90,9 @@ struct bsd_acct_struct {
struct timer_list timer;
};
-static struct bsd_acct_struct acct_globals __cacheline_aligned =
- {__SPIN_LOCK_UNLOCKED(acct_globals.lock)};
+static DEFINE_SPINLOCK(acct_lock);
+
+static struct bsd_acct_struct acct_globals __cacheline_aligned;
/*
* Called whenever the timer says to check the free space.
@@ -114,11 +114,11 @@ static int check_free_space(struct file *file)
sector_t resume;
sector_t suspend;
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
res = acct_globals.active;
if (!file || !acct_globals.needcheck)
goto out;
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
/* May block */
if (vfs_statfs(file->f_path.dentry, &sbuf))
@@ -140,7 +140,7 @@ static int check_free_space(struct file *file)
* If some joker switched acct_globals.file under us we'ld better be
* silent and _not_ touch anything.
*/
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
if (file != acct_globals.file) {
if (act)
res = act>0;
@@ -165,7 +165,7 @@ static int check_free_space(struct file *file)
add_timer(&acct_globals.timer);
res = acct_globals.active;
out:
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
return res;
}
@@ -173,7 +173,7 @@ out:
* Close the old accounting file (if currently open) and then replace
* it with file (if non-NULL).
*
- * NOTE: acct_globals.lock MUST be held on entry and exit.
+ * NOTE: acct_lock MUST be held on entry and exit.
*/
static void acct_file_reopen(struct file *file)
{
@@ -201,11 +201,11 @@ static void acct_file_reopen(struct file *file)
}
if (old_acct) {
mnt_unpin(old_acct->f_path.mnt);
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
do_acct_process(old_ns, old_acct);
filp_close(old_acct, NULL);
put_pid_ns(old_ns);
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
}
}
@@ -235,10 +235,10 @@ static int acct_on(char *name)
return error;
}
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
mnt_pin(file->f_path.mnt);
acct_file_reopen(file);
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
mntput(file->f_path.mnt); /* it's pinned, now give up active reference */
@@ -272,9 +272,9 @@ asmlinkage long sys_acct(const char __user *name)
} else {
error = security_acct(NULL);
if (!error) {
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
acct_file_reopen(NULL);
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
}
}
return error;
@@ -289,10 +289,10 @@ asmlinkage long sys_acct(const char __user *name)
*/
void acct_auto_close_mnt(struct vfsmount *m)
{
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
if (acct_globals.file && acct_globals.file->f_path.mnt == m)
acct_file_reopen(NULL);
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
}
/**
@@ -304,12 +304,12 @@ void acct_auto_close_mnt(struct vfsmount *m)
*/
void acct_auto_close(struct super_block *sb)
{
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
if (acct_globals.file &&
acct_globals.file->f_path.mnt->mnt_sb == sb) {
acct_file_reopen(NULL);
}
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
}
/*
@@ -594,15 +594,15 @@ void acct_process(void)
if (!acct_globals.file)
return;
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
file = acct_globals.file;
if (unlikely(!file)) {
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
return;
}
get_file(file);
ns = get_pid_ns(acct_globals.ns);
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
do_acct_process(ns, file);
fput(file);
--
1.5.3.4
--
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