From 215752fce31c80f3b3a1530bc7cddb3ba6a69b3a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 7 Aug 2014 06:23:41 -0400 Subject: [PATCH] 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 --- fs/mount.h | 1 + fs/namespace.c | 2 +- fs/super.c | 2 +- include/linux/acct.h | 6 +- include/linux/fs.h | 1 + kernel/acct.c | 135 ++++++++++++++++++------------------------- 6 files changed, 62 insertions(+), 85 deletions(-) diff --git a/fs/mount.h b/fs/mount.h index d55297f2fa05..0a2d1458681f 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -56,6 +56,7 @@ struct mount { int mnt_group_id; /* peer group identifier */ int mnt_expiry_mark; /* true if marked for expiry */ int mnt_pinned; + struct hlist_head mnt_pins; struct path mnt_ex_mountpoint; }; diff --git a/fs/namespace.c b/fs/namespace.c index 182bc41cd887..22e530addfaf 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -956,7 +956,7 @@ put_again: mnt->mnt_pinned = 0; rcu_read_unlock(); unlock_mount_hash(); - acct_auto_close_mnt(&mnt->mnt); + acct_auto_close_mnt(&mnt->mnt_pins); goto put_again; } if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) { diff --git a/fs/super.c b/fs/super.c index d20d5b11dedf..52ed93eb63df 100644 --- a/fs/super.c +++ b/fs/super.c @@ -703,7 +703,7 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) #endif if (flags & MS_RDONLY) - acct_auto_close(sb); + acct_auto_close(&sb->s_pins); shrink_dcache_sb(sb); remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); diff --git a/include/linux/acct.h b/include/linux/acct.h index 4a5b7cb56079..65a4f889182e 100644 --- a/include/linux/acct.h +++ b/include/linux/acct.h @@ -24,14 +24,14 @@ struct super_block; struct pacct_struct; struct pid_namespace; extern int acct_parm[]; /* for sysctl */ -extern void acct_auto_close_mnt(struct vfsmount *m); -extern void acct_auto_close(struct super_block *sb); +extern void acct_auto_close(struct hlist_head *); +extern void acct_auto_close_mnt(struct hlist_head *); extern void acct_collect(long exitcode, int group_dead); extern void acct_process(void); extern void acct_exit_ns(struct pid_namespace *); #else -#define acct_auto_close_mnt(x) do { } while (0) #define acct_auto_close(x) do { } while (0) +#define acct_auto_close_mnt(x) do { } while (0) #define acct_collect(x,y) do { } while (0) #define acct_process() do { } while (0) #define acct_exit_ns(ns) do { } while (0) diff --git a/include/linux/fs.h b/include/linux/fs.h index 4b7d57cf7863..17f70872a4a5 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1250,6 +1250,7 @@ struct super_block { /* AIO completions deferred from interrupt context */ struct workqueue_struct *s_dio_done_wq; + struct hlist_head s_pins; /* * Keep the lru lists last in the structure so they always sit on their 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 #include /* sector_div */ #include +#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); -- 2.39.2