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-rw-r--r--kernel/acct.c222
1 files changed, 144 insertions, 78 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index 91e1cfd734d..dd68b905941 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -75,37 +75,39 @@ int acct_parm[3] = {4, 2, 30};
/*
* External references and all of the globals.
*/
-static void do_acct_process(struct pid_namespace *ns, struct file *);
+static void do_acct_process(struct bsd_acct_struct *acct,
+ struct pid_namespace *ns, struct file *);
/*
* This structure is used so that all the data protected by lock
* can be placed in the same cache line as the lock. This primes
* the cache line to have the data after getting the lock.
*/
-struct acct_glbs {
- spinlock_t lock;
+struct bsd_acct_struct {
volatile int active;
volatile int needcheck;
struct file *file;
struct pid_namespace *ns;
struct timer_list timer;
+ struct list_head list;
};
-static struct acct_glbs acct_globals __cacheline_aligned =
- {__SPIN_LOCK_UNLOCKED(acct_globals.lock)};
+static DEFINE_SPINLOCK(acct_lock);
+static LIST_HEAD(acct_list);
/*
* Called whenever the timer says to check the free space.
*/
-static void acct_timeout(unsigned long unused)
+static void acct_timeout(unsigned long x)
{
- acct_globals.needcheck = 1;
+ struct bsd_acct_struct *acct = (struct bsd_acct_struct *)x;
+ acct->needcheck = 1;
}
/*
* Check the amount of free space and suspend/resume accordingly.
*/
-static int check_free_space(struct file *file)
+static int check_free_space(struct bsd_acct_struct *acct, struct file *file)
{
struct kstatfs sbuf;
int res;
@@ -113,11 +115,11 @@ static int check_free_space(struct file *file)
sector_t resume;
sector_t suspend;
- spin_lock(&acct_globals.lock);
- res = acct_globals.active;
- if (!file || !acct_globals.needcheck)
+ spin_lock(&acct_lock);
+ res = acct->active;
+ if (!file || !acct->needcheck)
goto out;
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
/* May block */
if (vfs_statfs(file->f_path.dentry, &sbuf))
@@ -136,35 +138,35 @@ static int check_free_space(struct file *file)
act = 0;
/*
- * If some joker switched acct_globals.file under us we'ld better be
+ * If some joker switched acct->file under us we'ld better be
* silent and _not_ touch anything.
*/
- spin_lock(&acct_globals.lock);
- if (file != acct_globals.file) {
+ spin_lock(&acct_lock);
+ if (file != acct->file) {
if (act)
res = act>0;
goto out;
}
- if (acct_globals.active) {
+ if (acct->active) {
if (act < 0) {
- acct_globals.active = 0;
+ acct->active = 0;
printk(KERN_INFO "Process accounting paused\n");
}
} else {
if (act > 0) {
- acct_globals.active = 1;
+ acct->active = 1;
printk(KERN_INFO "Process accounting resumed\n");
}
}
- del_timer(&acct_globals.timer);
- acct_globals.needcheck = 0;
- acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
- add_timer(&acct_globals.timer);
- res = acct_globals.active;
+ del_timer(&acct->timer);
+ acct->needcheck = 0;
+ acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ;
+ add_timer(&acct->timer);
+ res = acct->active;
out:
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
return res;
}
@@ -172,39 +174,41 @@ 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)
+static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file,
+ struct pid_namespace *ns)
{
struct file *old_acct = NULL;
struct pid_namespace *old_ns = NULL;
- if (acct_globals.file) {
- old_acct = acct_globals.file;
- old_ns = acct_globals.ns;
- del_timer(&acct_globals.timer);
- acct_globals.active = 0;
- acct_globals.needcheck = 0;
- acct_globals.file = NULL;
+ if (acct->file) {
+ old_acct = acct->file;
+ old_ns = acct->ns;
+ del_timer(&acct->timer);
+ acct->active = 0;
+ acct->needcheck = 0;
+ acct->file = NULL;
+ acct->ns = NULL;
+ list_del(&acct->list);
}
if (file) {
- acct_globals.file = file;
- acct_globals.ns = get_pid_ns(task_active_pid_ns(current));
- acct_globals.needcheck = 0;
- acct_globals.active = 1;
+ acct->file = file;
+ acct->ns = ns;
+ acct->needcheck = 0;
+ acct->active = 1;
+ list_add(&acct->list, &acct_list);
/* It's been deleted if it was used before so this is safe */
- init_timer(&acct_globals.timer);
- acct_globals.timer.function = acct_timeout;
- acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
- add_timer(&acct_globals.timer);
+ setup_timer(&acct->timer, acct_timeout, (unsigned long)acct);
+ acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ;
+ add_timer(&acct->timer);
}
if (old_acct) {
mnt_unpin(old_acct->f_path.mnt);
- spin_unlock(&acct_globals.lock);
- do_acct_process(old_ns, old_acct);
+ spin_unlock(&acct_lock);
+ do_acct_process(acct, old_ns, old_acct);
filp_close(old_acct, NULL);
- put_pid_ns(old_ns);
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
}
}
@@ -212,6 +216,8 @@ static int acct_on(char *name)
{
struct file *file;
int error;
+ struct pid_namespace *ns;
+ struct bsd_acct_struct *acct = NULL;
/* Difference from BSD - they don't do O_APPEND */
file = filp_open(name, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
@@ -228,18 +234,34 @@ static int acct_on(char *name)
return -EIO;
}
+ ns = task_active_pid_ns(current);
+ if (ns->bacct == NULL) {
+ acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL);
+ if (acct == NULL) {
+ filp_close(file, NULL);
+ return -ENOMEM;
+ }
+ }
+
error = security_acct(file);
if (error) {
+ kfree(acct);
filp_close(file, NULL);
return error;
}
- spin_lock(&acct_globals.lock);
+ spin_lock(&acct_lock);
+ if (ns->bacct == NULL) {
+ ns->bacct = acct;
+ acct = NULL;
+ }
+
mnt_pin(file->f_path.mnt);
- acct_file_reopen(file);
- spin_unlock(&acct_globals.lock);
+ acct_file_reopen(ns->bacct, file, ns);
+ spin_unlock(&acct_lock);
mntput(file->f_path.mnt); /* it's pinned, now give up active reference */
+ kfree(acct);
return 0;
}
@@ -269,11 +291,17 @@ asmlinkage long sys_acct(const char __user *name)
error = acct_on(tmp);
putname(tmp);
} else {
+ struct bsd_acct_struct *acct;
+
+ acct = task_active_pid_ns(current)->bacct;
+ if (acct == NULL)
+ return 0;
+
error = security_acct(NULL);
if (!error) {
- spin_lock(&acct_globals.lock);
- acct_file_reopen(NULL);
- spin_unlock(&acct_globals.lock);
+ spin_lock(&acct_lock);
+ acct_file_reopen(acct, NULL, NULL);
+ spin_unlock(&acct_lock);
}
}
return error;
@@ -288,10 +316,16 @@ asmlinkage long sys_acct(const char __user *name)
*/
void acct_auto_close_mnt(struct vfsmount *m)
{
- spin_lock(&acct_globals.lock);
- if (acct_globals.file && acct_globals.file->f_path.mnt == m)
- acct_file_reopen(NULL);
- spin_unlock(&acct_globals.lock);
+ struct bsd_acct_struct *acct;
+
+ spin_lock(&acct_lock);
+restart:
+ list_for_each_entry(acct, &acct_list, list)
+ if (acct->file && acct->file->f_path.mnt == m) {
+ acct_file_reopen(acct, NULL, NULL);
+ goto restart;
+ }
+ spin_unlock(&acct_lock);
}
/**
@@ -303,12 +337,31 @@ void acct_auto_close_mnt(struct vfsmount *m)
*/
void acct_auto_close(struct super_block *sb)
{
- spin_lock(&acct_globals.lock);
- if (acct_globals.file &&
- acct_globals.file->f_path.mnt->mnt_sb == sb) {
- acct_file_reopen(NULL);
+ struct bsd_acct_struct *acct;
+
+ spin_lock(&acct_lock);
+restart:
+ list_for_each_entry(acct, &acct_list, list)
+ if (acct->file && acct->file->f_path.mnt->mnt_sb == sb) {
+ acct_file_reopen(acct, NULL, NULL);
+ goto restart;
+ }
+ spin_unlock(&acct_lock);
+}
+
+void acct_exit_ns(struct pid_namespace *ns)
+{
+ struct bsd_acct_struct *acct;
+
+ spin_lock(&acct_lock);
+ acct = ns->bacct;
+ if (acct != NULL) {
+ if (acct->file != NULL)
+ acct_file_reopen(acct, NULL, NULL);
+
+ kfree(acct);
}
- spin_unlock(&acct_globals.lock);
+ spin_unlock(&acct_lock);
}
/*
@@ -425,7 +478,8 @@ static u32 encode_float(u64 value)
/*
* do_acct_process does all actual work. Caller holds the reference to file.
*/
-static void do_acct_process(struct pid_namespace *ns, struct file *file)
+static void do_acct_process(struct bsd_acct_struct *acct,
+ struct pid_namespace *ns, struct file *file)
{
struct pacct_struct *pacct = &current->signal->pacct;
acct_t ac;
@@ -440,7 +494,7 @@ static void do_acct_process(struct pid_namespace *ns, struct file *file)
* First check to see if there is enough free_space to continue
* the process accounting system.
*/
- if (!check_free_space(file))
+ if (!check_free_space(acct, file))
return;
/*
@@ -577,34 +631,46 @@ void acct_collect(long exitcode, int group_dead)
spin_unlock_irq(&current->sighand->siglock);
}
-/**
- * acct_process - now just a wrapper around do_acct_process
- * @exitcode: task exit code
- *
- * handles process accounting for an exiting task
- */
-void acct_process(void)
+static void acct_process_in_ns(struct pid_namespace *ns)
{
struct file *file = NULL;
- struct pid_namespace *ns;
+ struct bsd_acct_struct *acct;
+ acct = ns->bacct;
/*
* accelerate the common fastpath:
*/
- if (!acct_globals.file)
+ if (!acct || !acct->file)
return;
- spin_lock(&acct_globals.lock);
- file = acct_globals.file;
+ spin_lock(&acct_lock);
+ file = acct->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);
+ do_acct_process(acct, ns, file);
fput(file);
- put_pid_ns(ns);
+}
+
+/**
+ * acct_process - now just a wrapper around acct_process_in_ns,
+ * which in turn is a wrapper around do_acct_process.
+ *
+ * handles process accounting for an exiting task
+ */
+void acct_process(void)
+{
+ struct pid_namespace *ns;
+
+ /*
+ * This loop is safe lockless, since current is still
+ * alive and holds its namespace, which in turn holds
+ * its parent.
+ */
+ for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent)
+ acct_process_in_ns(ns);
}