xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

acct: get rid of acct_list

Browse Source 
Put these suckers on per-vfsmount and per-superblock lists instead.
Note: right now it's still acct_lock for everything, but that's
going to change.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2014-08-07 06:23:41 -04:00
parent 54a4d58a64
commit 215752fce3
6 changed files with 62 additions and 85 deletions
Download Patch File Download Diff File Expand all files Collapse all files

135
kernel/acct.c
View File

@@ -59,6 +59,7 @@
#include <asm/div64.h>
#include <linux/blkdev.h> /* sector_div */
#include <linux/pid_namespace.h>
#include <../fs/mount.h> /* will go away when we refactor */
/*
* These constants control the amount of freespace that suspend and
@@ -79,16 +80,16 @@ static void do_acct_process(struct bsd_acct_struct *acct);
struct bsd_acct_struct {
long count;
struct hlist_node s_list;
struct hlist_node m_list;
struct mutex lock;
int active;
unsigned long needcheck;
struct file *file;
struct pid_namespace *ns;
struct list_head list;
};
static DEFINE_SPINLOCK(acct_lock);
static LIST_HEAD(acct_list);
/*
* Check the amount of free space and suspend/resume accordingly.
@@ -133,25 +134,33 @@ static void acct_put(struct bsd_acct_struct *p)
spin_unlock(&acct_lock);
}
static struct bsd_acct_struct *acct_get(struct bsd_acct_struct **p)
static struct bsd_acct_struct *__acct_get(struct bsd_acct_struct *res)
{
res->count++;
spin_unlock(&acct_lock);
mutex_lock(&res->lock);
if (!res->ns) {
mutex_unlock(&res->lock);
spin_lock(&acct_lock);
if (!--res->count)
kfree(res);
return NULL;
}
return res;
}
static struct bsd_acct_struct *acct_get(struct pid_namespace *ns)
{
struct bsd_acct_struct *res;
spin_lock(&acct_lock);
again:
res = *p;
if (res)
res->count++;
spin_unlock(&acct_lock);
if (res) {
mutex_lock(&res->lock);
if (!res->ns) {
mutex_unlock(&res->lock);
spin_lock(&acct_lock);
if (!--res->count)
kfree(res);
goto again;
}
if (!ns->bacct) {
spin_unlock(&acct_lock);
return NULL;
}
res = __acct_get(ns->bacct);
if (!res)
goto again;
return res;
}
@@ -162,7 +171,8 @@ static void acct_kill(struct bsd_acct_struct *acct,
struct file *file = acct->file;
struct pid_namespace *ns = acct->ns;
spin_lock(&acct_lock);
list_del(&acct->list);
hlist_del(&acct->m_list);
hlist_del(&acct->s_list);
mnt_unpin(file->f_path.mnt);
spin_unlock(&acct_lock);
do_acct_process(acct);
@@ -170,8 +180,10 @@ static void acct_kill(struct bsd_acct_struct *acct,
spin_lock(&acct_lock);
ns->bacct = new;
if (new) {
mnt_pin(new->file->f_path.mnt);
list_add(&new->list, &acct_list);
struct vfsmount *m = new->file->f_path.mnt;
mnt_pin(m);
hlist_add_head(&new->s_list, &m->mnt_sb->s_pins);
hlist_add_head(&new->m_list, &real_mount(m)->mnt_pins);
}
acct->ns = NULL;
mutex_unlock(&acct->lock);
@@ -218,14 +230,15 @@ static int acct_on(struct filename *pathname)
mutex_init(&acct->lock);
mnt = file->f_path.mnt;
old = acct_get(&ns->bacct);
old = acct_get(ns);
if (old) {
acct_kill(old, acct);
} else {
spin_lock(&acct_lock);
ns->bacct = acct;
mnt_pin(mnt);
list_add(&acct->list, &acct_list);
hlist_add_head(&acct->s_list, &mnt->mnt_sb->s_pins);
hlist_add_head(&acct->m_list, &real_mount(mnt)->mnt_pins);
spin_unlock(&acct_lock);
}
mntput(mnt); /* it's pinned, now give up active reference */
@@ -261,79 +274,41 @@ SYSCALL_DEFINE1(acct, const char __user *, name)
mutex_unlock(&acct_on_mutex);
putname(tmp);
} else {
acct_kill(acct_get(&task_active_pid_ns(current)->bacct), NULL);
acct_kill(acct_get(task_active_pid_ns(current)), NULL);
}
return error;
}
/**
* acct_auto_close - turn off a filesystem's accounting if it is on
* @m: vfsmount being shut down
*
* If the accounting is turned on for a file in the subtree pointed to
* to by m, turn accounting off. Done when m is about to die.
*/
void acct_auto_close_mnt(struct vfsmount *m)
void acct_auto_close_mnt(struct hlist_head *list)
{
struct bsd_acct_struct *acct;
spin_lock(&acct_lock);
restart:
list_for_each_entry(acct, &acct_list, list)
if (acct->file->f_path.mnt == m) {
acct->count++;
spin_unlock(&acct_lock);
mutex_lock(&acct->lock);
if (!acct->ns) {
mutex_unlock(&acct->lock);
spin_lock(&acct_lock);
if (!--acct->count)
kfree(acct);
goto restart;
}
acct_kill(acct, NULL);
spin_lock(&acct_lock);
goto restart;
}
while (1) {
spin_lock(&acct_lock);
if (!list->first)
break;
acct_kill(__acct_get(hlist_entry(list->first,
struct bsd_acct_struct,
m_list)), NULL);
}
spin_unlock(&acct_lock);
}
/**
* acct_auto_close - turn off a filesystem's accounting if it is on
* @sb: super block for the filesystem
*
* If the accounting is turned on for a file in the filesystem pointed
* to by sb, turn accounting off.
*/
void acct_auto_close(struct super_block *sb)
void acct_auto_close(struct hlist_head *list)
{
struct bsd_acct_struct *acct;
spin_lock(&acct_lock);
restart:
list_for_each_entry(acct, &acct_list, list)
if (acct->file->f_path.dentry->d_sb == sb) {
acct->count++;
spin_unlock(&acct_lock);
mutex_lock(&acct->lock);
if (!acct->ns) {
mutex_unlock(&acct->lock);
spin_lock(&acct_lock);
if (!--acct->count)
kfree(acct);
goto restart;
}
acct_kill(acct, NULL);
spin_lock(&acct_lock);
goto restart;
}
while (1) {
spin_lock(&acct_lock);
if (!list->first)
break;
acct_kill(__acct_get(hlist_entry(list->first,
struct bsd_acct_struct,
s_list)), NULL);
}
spin_unlock(&acct_lock);
}
void acct_exit_ns(struct pid_namespace *ns)
{
acct_kill(acct_get(&ns->bacct), NULL);
acct_kill(acct_get(ns), NULL);
}
/*
@@ -602,7 +577,7 @@ void acct_collect(long exitcode, int group_dead)
static void slow_acct_process(struct pid_namespace *ns)
{
for ( ; ns; ns = ns->parent) {
struct bsd_acct_struct *acct = acct_get(&ns->bacct);
struct bsd_acct_struct *acct = acct_get(ns);
if (acct) {
do_acct_process(acct);
mutex_unlock(&acct->lock);