acct: get rid of acct_list

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>

1 files changed, 55 insertions, 80 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index 019f012a3c6f..21fbb3c27c2a 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -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);