The patch titled
bsdacct: turn the acct_lock from on-the-struct to global
has been added to the -mm tree. Its filename is
bsdacct-turn-the-acct_lock-from-on-the-struct-to-global.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: bsdacct: turn the acct_lock from on-the-struct to global
From: Pavel Emelyanov <xemul@xxxxxxxxxx>
Don't use per-bsd-acct-struct lock, but work with a global one.
This lock is taken for short periods, so it doesn't seem it'll become a
bottleneck, but it will allow us to easily avoid many locking difficulties
in the future.
So this is a mostly s/acct_globals.lock/acct_lock/ over the file.
Signed-off-by: Pavel Emelyanov <xemul@xxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/acct.c | 42 +++++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 21 deletions(-)
diff -puN kernel/acct.c~bsdacct-turn-the-acct_lock-from-on-the-struct-to-global kernel/acct.c
--- a/kernel/acct.c~bsdacct-turn-the-acct_lock-from-on-the-struct-to-global
+++ a/kernel/acct.c
@@ -83,7 +83,6 @@ static void do_acct_process(struct pid_n
* 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
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
* 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
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
}
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 __us
} 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 __us
*/
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
*/
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);
_
Patches currently in -mm which might be from xemul@xxxxxxxxxx are
origin.patch
mark-res_counter_charge_locked-with-__must_check.patch
memcg-make-global-var-read_mostly.patch
memcg-avoid-unnecessary-initialization.patch
memcg-better-migration-handling.patch
bsdacct-rename-acct_blbls-to-bsd_acct_struct.patch
pidns-use-kzalloc-when-allocating-new-pid_namespace-struct.patch
pidns-add-the-struct-bsd_acct_struct-pointer-on-pid_namespace-struct.patch
bsdacct-truthify-a-comment-near-acct_process.patch
bsdacct-make-check-timer-accept-a-bsd_acct_struct-argument.patch
bsdacct-turn-the-acct_lock-from-on-the-struct-to-global.patch
bsdacct-make-internal-code-work-with-passed-bsd_acct_struct-not-global.patch
bsdacct-switch-from-global-bsd_acct_struct-instance-to-per-pidns-one.patch
bsdacct-turn-acct-off-for-all-pidns-s-on-umount-time.patch
bsdacct-account-dying-tasks-in-all-relevant-namespaces.patch
reiser4.patch
put_pid-make-sure-we-dont-free-the-live-pid.patch
--
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