From 0b6b030fc30d169bb406b34b4fc60d99dde4a9c6 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Fri, 25 Jul 2008 01:48:47 -0700 Subject: bsdacct: switch from global bsd_acct_struct instance to per-pidns one Allocate the structure on the first call to sys_acct(). After this each namespace, that ordered the accounting, will live with this structure till its own death. Two notes - routines, that close the accounting on fs umount time use the init_pid_ns's acct by now; - accounting routine accounts to dying task's namespace (also by now). Signed-off-by: Pavel Emelyanov Cc: Balbir Singh Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/acct.h | 3 ++ kernel/acct.c | 84 +++++++++++++++++++++++++++++++++++++++----------- kernel/pid_namespace.c | 2 ++ 3 files changed, 71 insertions(+), 18 deletions(-) diff --git a/include/linux/acct.h b/include/linux/acct.h index e8cae54..882dc72 100644 --- a/include/linux/acct.h +++ b/include/linux/acct.h @@ -120,17 +120,20 @@ struct acct_v3 struct vfsmount; struct super_block; struct pacct_struct; +struct pid_namespace; extern void acct_auto_close_mnt(struct vfsmount *m); extern void acct_auto_close(struct super_block *sb); extern void acct_init_pacct(struct pacct_struct *pacct); 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_init_pacct(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) #endif /* diff --git a/kernel/acct.c b/kernel/acct.c index 72d4760..febbbc6 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -93,8 +93,6 @@ struct bsd_acct_struct { static DEFINE_SPINLOCK(acct_lock); -static struct bsd_acct_struct acct_globals __cacheline_aligned; - /* * Called whenever the timer says to check the free space. */ @@ -176,7 +174,8 @@ out: * * NOTE: acct_lock MUST be held on entry and exit. */ -static void acct_file_reopen(struct bsd_acct_struct *acct, 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; @@ -188,10 +187,11 @@ static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file) acct->active = 0; acct->needcheck = 0; acct->file = NULL; + acct->ns = NULL; } if (file) { acct->file = file; - acct->ns = get_pid_ns(task_active_pid_ns(current)); + acct->ns = ns; acct->needcheck = 0; acct->active = 1; /* It's been deleted if it was used before so this is safe */ @@ -204,7 +204,6 @@ static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file) 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_lock); } } @@ -213,6 +212,8 @@ 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); @@ -229,18 +230,34 @@ 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_lock); + if (ns->bacct == NULL) { + ns->bacct = acct; + acct = NULL; + } + mnt_pin(file->f_path.mnt); - acct_file_reopen(&acct_globals, file); + 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; } @@ -270,10 +287,16 @@ 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_lock); - acct_file_reopen(&acct_globals, NULL); + acct_file_reopen(acct, NULL, NULL); spin_unlock(&acct_lock); } } @@ -289,9 +312,15 @@ asmlinkage long sys_acct(const char __user *name) */ void acct_auto_close_mnt(struct vfsmount *m) { + struct bsd_acct_struct *acct; + + acct = init_pid_ns.bacct; + if (acct == NULL) + return; + spin_lock(&acct_lock); - if (acct_globals.file && acct_globals.file->f_path.mnt == m) - acct_file_reopen(&acct_globals, NULL); + if (acct->file && acct->file->f_path.mnt == m) + acct_file_reopen(acct, NULL, NULL); spin_unlock(&acct_lock); } @@ -304,10 +333,29 @@ void acct_auto_close_mnt(struct vfsmount *m) */ void acct_auto_close(struct super_block *sb) { + struct bsd_acct_struct *acct; + + acct = init_pid_ns.bacct; + if (acct == NULL) + return; + spin_lock(&acct_lock); - if (acct_globals.file && - acct_globals.file->f_path.mnt->mnt_sb == sb) { - acct_file_reopen(&acct_globals, NULL); + if (acct->file && acct->file->f_path.mnt->mnt_sb == sb) + acct_file_reopen(acct, NULL, NULL); + 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_lock); } @@ -587,25 +635,25 @@ void acct_collect(long exitcode, int group_dead) void acct_process(void) { struct file *file = NULL; - struct pid_namespace *ns; + struct pid_namespace *ns = task_active_pid_ns(current); + struct bsd_acct_struct *acct; + acct = ns->bacct; /* * accelerate the common fastpath: */ - if (!acct_globals.file) + if (!acct || !acct->file) return; spin_lock(&acct_lock); - file = acct_globals.file; + file = acct->file; if (unlikely(!file)) { spin_unlock(&acct_lock); return; } get_file(file); - ns = get_pid_ns(acct_globals.ns); spin_unlock(&acct_lock); - do_acct_process(&acct_globals, ns, file); + do_acct_process(acct, ns, file); fput(file); - put_pid_ns(ns); } diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 06331cc..ea567b7 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -12,6 +12,7 @@ #include #include #include +#include #define BITS_PER_PAGE (PAGE_SIZE*8) @@ -181,6 +182,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) /* Child reaper for the pid namespace is going away */ pid_ns->child_reaper = NULL; + acct_exit_ns(pid_ns); return; } -- cgit v1.1