* [RFC PATCH 1/2] mqueue ns: move mqueue_mnt into struct ipc_namespace
[not found] ` <20081215233747.GA27553-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
@ 2008-12-15 23:38 ` Serge E. Hallyn
2008-12-15 23:38 ` [RFC PATCH 2/2] ipc namespaces: implement support for posix msqueues Serge E. Hallyn
2008-12-16 8:11 ` [RFC patch 0/2] posix mqueue namespace (v11) Cedric Le Goater
2 siblings, 0 replies; 5+ messages in thread
From: Serge E. Hallyn @ 2008-12-15 23:38 UTC (permalink / raw)
To: Linux Containers
Move mqueue vfsmount plus a few tunables into the
ipc_namespace struct. The CONFIG_IPC_NS boolean
and the ipc_namespace struct will serve both the
posix message queue namespaces and the SYSV ipc
namespaces.
Largely based on previous version by Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org> and
Nadia Derbey <Nadia.Derbey-6ktuUTfB/bM@public.gmane.org>.
Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
include/linux/ipc_namespace.h | 32 ++++++++++--
init/Kconfig | 4 +-
ipc/mqueue.c | 116 ++++++++++++++++++++++-------------------
ipc/msgutil.c | 21 +++++++
ipc/namespace.c | 2 +
ipc/util.c | 9 ---
ipc/util.h | 15 +++++
7 files changed, 131 insertions(+), 68 deletions(-)
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index ea330f9..532598f 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -44,24 +44,48 @@ struct ipc_namespace {
int shm_tot;
struct notifier_block ipcns_nb;
+
+ struct vfsmount *mq_mnt;
+ unsigned int mq_queues_count;
+ unsigned int mq_queues_max;
+ unsigned int mq_msg_max;
+ unsigned int mq_msgsize_max;
+
};
extern struct ipc_namespace init_ipc_ns;
extern atomic_t nr_ipc_ns;
-#ifdef CONFIG_SYSVIPC
+#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
#define INIT_IPC_NS(ns) .ns = &init_ipc_ns,
+#else
+#define INIT_IPC_NS(ns)
+#endif
+#ifdef CONFIG_SYSVIPC
extern int register_ipcns_notifier(struct ipc_namespace *);
extern int cond_register_ipcns_notifier(struct ipc_namespace *);
extern void unregister_ipcns_notifier(struct ipc_namespace *);
extern int ipcns_notify(unsigned long);
-
#else /* CONFIG_SYSVIPC */
-#define INIT_IPC_NS(ns)
+#define register_ipcns_notifier(ns)
+#define cond_register_ipcns_notifier(ns)
+#define unregister_ipcns_notifier(ns)
+#define ipcns_notify(l)
#endif /* CONFIG_SYSVIPC */
-#if defined(CONFIG_SYSVIPC) && defined(CONFIG_IPC_NS)
+#ifdef CONFIG_POSIX_MQUEUE
+extern void mq_init_ns(struct ipc_namespace *ns);
+/* default values */
+#define DFLT_QUEUESMAX 256 /* max number of message queues */
+#define DFLT_MSGMAX 10 /* max number of messages in each queue */
+#define HARD_MSGMAX (131072/sizeof(void *))
+#define DFLT_MSGSIZEMAX 8192 /* max message size */
+#else
+#define mq_init_ns(ns)
+#endif
+
+#if defined(CONFIG_IPC_NS)
extern void free_ipc_ns(struct kref *kref);
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
struct ipc_namespace *ns);
diff --git a/init/Kconfig b/init/Kconfig
index ce75d2d..32c6315 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -489,10 +489,10 @@ config UTS_NS
config IPC_NS
bool "IPC namespace"
- depends on NAMESPACES && SYSVIPC
+ depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
help
In this namespace tasks work with IPC ids which correspond to
- different IPC objects in different namespaces
+ different IPC objects in different namespaces.
config USER_NS
bool "User namespace (EXPERIMENTAL)"
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index d9393f8..01d64a0 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -31,6 +31,7 @@
#include <linux/mutex.h>
#include <linux/nsproxy.h>
#include <linux/pid.h>
+#include <linux/ipc_namespace.h>
#include <net/sock.h>
#include "util.h"
@@ -46,12 +47,6 @@
#define STATE_PENDING 1
#define STATE_READY 2
-/* default values */
-#define DFLT_QUEUESMAX 256 /* max number of message queues */
-#define DFLT_MSGMAX 10 /* max number of messages in each queue */
-#define HARD_MSGMAX (131072/sizeof(void*))
-#define DFLT_MSGSIZEMAX 8192 /* max message size */
-
/*
* Define the ranges various user-specified maximum values can
* be set to.
@@ -95,12 +90,6 @@ static void remove_notification(struct mqueue_inode_info *info);
static spinlock_t mq_lock;
static struct kmem_cache *mqueue_inode_cachep;
-static struct vfsmount *mqueue_mnt;
-
-static unsigned int queues_count;
-static unsigned int queues_max = DFLT_QUEUESMAX;
-static unsigned int msg_max = DFLT_MSGMAX;
-static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
static struct ctl_table_header * mq_sysctl_table;
@@ -109,11 +98,25 @@ static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
return container_of(inode, struct mqueue_inode_info, vfs_inode);
}
+void mq_init_ns(struct ipc_namespace *ns) {
+ ns->mq_queues_count = 0;
+ ns->mq_queues_max = DFLT_QUEUESMAX;
+ ns->mq_msg_max = DFLT_MSGMAX;
+ ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+ ns->mq_mnt = mntget(init_ipc_ns.mq_mnt);
+}
+
+void mq_exit_ns(struct ipc_namespace *ns) {
+ /* will need to clear out ns->mq_mnt->mnt_sb->s_fs_info here */
+ mntput(ns->mq_mnt);
+}
+
static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
struct mq_attr *attr)
{
struct user_struct *u = current_user();
struct inode *inode;
+ struct ipc_namespace *ipc_ns = &init_ipc_ns;
inode = new_inode(sb);
if (inode) {
@@ -142,8 +145,8 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
info->qsize = 0;
info->user = NULL; /* set when all is ok */
memset(&info->attr, 0, sizeof(info->attr));
- info->attr.mq_maxmsg = msg_max;
- info->attr.mq_msgsize = msgsize_max;
+ info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
+ info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
if (attr) {
info->attr.mq_maxmsg = attr->mq_maxmsg;
info->attr.mq_msgsize = attr->mq_msgsize;
@@ -243,6 +246,7 @@ static void mqueue_delete_inode(struct inode *inode)
struct user_struct *user;
unsigned long mq_bytes;
int i;
+ struct ipc_namespace *ipc_ns = &init_ipc_ns;
if (S_ISDIR(inode->i_mode)) {
clear_inode(inode);
@@ -263,7 +267,7 @@ static void mqueue_delete_inode(struct inode *inode)
if (user) {
spin_lock(&mq_lock);
user->mq_bytes -= mq_bytes;
- queues_count--;
+ ipc_ns->mq_queues_count--;
spin_unlock(&mq_lock);
free_uid(user);
}
@@ -275,20 +279,22 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
struct inode *inode;
struct mq_attr *attr = dentry->d_fsdata;
int error;
+ struct ipc_namespace *ipc_ns = &init_ipc_ns;
spin_lock(&mq_lock);
- if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
+ if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
+ !capable(CAP_SYS_RESOURCE)) {
error = -ENOSPC;
goto out_lock;
}
- queues_count++;
+ ipc_ns->mq_queues_count++;
spin_unlock(&mq_lock);
inode = mqueue_get_inode(dir->i_sb, mode, attr);
if (!inode) {
error = -ENOMEM;
spin_lock(&mq_lock);
- queues_count--;
+ ipc_ns->mq_queues_count--;
goto out_lock;
}
@@ -566,7 +572,7 @@ static void remove_notification(struct mqueue_inode_info *info)
info->notify_owner = NULL;
}
-static int mq_attr_ok(struct mq_attr *attr)
+static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
{
if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
return 0;
@@ -574,8 +580,8 @@ static int mq_attr_ok(struct mq_attr *attr)
if (attr->mq_maxmsg > HARD_MSGMAX)
return 0;
} else {
- if (attr->mq_maxmsg > msg_max ||
- attr->mq_msgsize > msgsize_max)
+ if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
+ attr->mq_msgsize > ipc_ns->mq_msgsize_max)
return 0;
}
/* check for overflow */
@@ -591,8 +597,9 @@ static int mq_attr_ok(struct mq_attr *attr)
/*
* Invoked when creating a new queue via sys_mq_open
*/
-static struct file *do_create(struct dentry *dir, struct dentry *dentry,
- int oflag, mode_t mode, struct mq_attr __user *u_attr)
+static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
+ struct dentry *dentry, int oflag, mode_t mode,
+ struct mq_attr __user *u_attr)
{
const struct cred *cred = current_cred();
struct mq_attr attr;
@@ -604,14 +611,14 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry,
if (copy_from_user(&attr, u_attr, sizeof(attr)))
goto out;
ret = -EINVAL;
- if (!mq_attr_ok(&attr))
+ if (!mq_attr_ok(ipc_ns, &attr))
goto out;
/* store for use during create */
dentry->d_fsdata = &attr;
}
mode &= ~current->fs->umask;
- ret = mnt_want_write(mqueue_mnt);
+ ret = mnt_want_write(ipc_ns->mq_mnt);
if (ret)
goto out;
ret = vfs_create(dir->d_inode, dentry, mode, NULL);
@@ -619,24 +626,25 @@ static struct file *do_create(struct dentry *dir, struct dentry *dentry,
if (ret)
goto out_drop_write;
- result = dentry_open(dentry, mqueue_mnt, oflag, cred);
+ result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
/*
* dentry_open() took a persistent mnt_want_write(),
* so we can now drop this one.
*/
- mnt_drop_write(mqueue_mnt);
+ mnt_drop_write(ipc_ns->mq_mnt);
return result;
out_drop_write:
- mnt_drop_write(mqueue_mnt);
+ mnt_drop_write(ipc_ns->mq_mnt);
out:
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(ipc_ns->mq_mnt);
return ERR_PTR(ret);
}
/* Opens existing queue */
-static struct file *do_open(struct dentry *dentry, int oflag)
+static struct file *do_open(struct ipc_namespace *ipc_ns,
+ struct dentry *dentry, int oflag)
{
const struct cred *cred = current_cred();
@@ -645,17 +653,17 @@ static struct file *do_open(struct dentry *dentry, int oflag)
if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(ipc_ns->mq_mnt);
return ERR_PTR(-EINVAL);
}
if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(ipc_ns->mq_mnt);
return ERR_PTR(-EACCES);
}
- return dentry_open(dentry, mqueue_mnt, oflag, cred);
+ return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
}
asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
@@ -665,6 +673,7 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
struct file *filp;
char *name;
int fd, error;
+ struct ipc_namespace *ipc_ns = &init_ipc_ns;
error = audit_mq_open(oflag, mode, u_attr);
if (error != 0)
@@ -677,13 +686,13 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
if (fd < 0)
goto out_putname;
- mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
+ dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
goto out_err;
}
- mntget(mqueue_mnt);
+ mntget(ipc_ns->mq_mnt);
if (oflag & O_CREAT) {
if (dentry->d_inode) { /* entry already exists */
@@ -691,17 +700,17 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
error = -EEXIST;
if (oflag & O_EXCL)
goto out;
- filp = do_open(dentry, oflag);
+ filp = do_open(ipc_ns, dentry, oflag);
} else {
- filp = do_create(mqueue_mnt->mnt_root, dentry,
- oflag, mode, u_attr);
+ filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
+ dentry, oflag, mode, u_attr);
}
} else {
error = -ENOENT;
if (!dentry->d_inode)
goto out;
audit_inode(name, dentry);
- filp = do_open(dentry, oflag);
+ filp = do_open(ipc_ns, dentry, oflag);
}
if (IS_ERR(filp)) {
@@ -714,13 +723,13 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
out:
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(ipc_ns->mq_mnt);
out_putfd:
put_unused_fd(fd);
out_err:
fd = error;
out_upsem:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+ mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
out_putname:
putname(name);
return fd;
@@ -732,14 +741,15 @@ asmlinkage long sys_mq_unlink(const char __user *u_name)
char *name;
struct dentry *dentry;
struct inode *inode = NULL;
+ struct ipc_namespace *ipc_ns = &init_ipc_ns;
name = getname(u_name);
if (IS_ERR(name))
return PTR_ERR(name);
- mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
+ mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
I_MUTEX_PARENT);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock;
@@ -753,16 +763,16 @@ asmlinkage long sys_mq_unlink(const char __user *u_name)
inode = dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
- err = mnt_want_write(mqueue_mnt);
+ err = mnt_want_write(ipc_ns->mq_mnt);
if (err)
goto out_err;
err = vfs_unlink(dentry->d_parent->d_inode, dentry);
- mnt_drop_write(mqueue_mnt);
+ mnt_drop_write(ipc_ns->mq_mnt);
out_err:
dput(dentry);
out_unlock:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+ mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
putname(name);
if (inode)
iput(inode);
@@ -1211,14 +1221,14 @@ static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
static ctl_table mq_sysctls[] = {
{
.procname = "queues_max",
- .data = &queues_max,
+ .data = &init_ipc_ns.mq_queues_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.procname = "msg_max",
- .data = &msg_max,
+ .data = &init_ipc_ns.mq_msg_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
@@ -1227,7 +1237,7 @@ static ctl_table mq_sysctls[] = {
},
{
.procname = "msgsize_max",
- .data = &msgsize_max,
+ .data = &init_ipc_ns.mq_msgsize_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
@@ -1273,13 +1283,13 @@ static int __init init_mqueue_fs(void)
if (error)
goto out_sysctl;
- if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
- error = PTR_ERR(mqueue_mnt);
+ init_ipc_ns.mq_mnt = kern_mount(&mqueue_fs_type);
+ if (IS_ERR(init_ipc_ns.mq_mnt)) {
+ error = PTR_ERR(init_ipc_ns.mq_mnt);
goto out_filesystem;
}
/* internal initialization - not common for vfs */
- queues_count = 0;
spin_lock_init(&mq_lock);
return 0;
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index c82c215..c197cd1 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -13,10 +13,31 @@
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/ipc.h>
+#include <linux/ipc_namespace.h>
#include <asm/uaccess.h>
#include "util.h"
+/*
+ * The next 2 defines are here bc this is the only file
+ * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
+ * and not CONFIG_IPC_NS.
+ */
+struct ipc_namespace init_ipc_ns = {
+ .kref = {
+ .refcount = ATOMIC_INIT(2),
+ },
+#ifdef CONFIG_POSIX_MQUEUE
+ .mq_mnt = NULL,
+ .mq_queues_count = 0,
+ .mq_queues_max = DFLT_QUEUESMAX,
+ .mq_msg_max = DFLT_MSGMAX,
+ .mq_msgsize_max = DFLT_MSGSIZEMAX,
+#endif
+};
+
+atomic_t nr_ipc_ns = ATOMIC_INIT(1);
+
struct msg_msgseg {
struct msg_msgseg* next;
/* the next part of the message follows immediately */
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 9171d94..4b4dc6d 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -25,6 +25,7 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
+ mq_init_ns(ns);
/*
* msgmni has already been computed for the new ipc ns.
@@ -101,6 +102,7 @@ void free_ipc_ns(struct kref *kref)
sem_exit_ns(ns);
msg_exit_ns(ns);
shm_exit_ns(ns);
+ mq_exit_ns(ns);
kfree(ns);
atomic_dec(&nr_ipc_ns);
diff --git a/ipc/util.c b/ipc/util.c
index 5a1808c..ac971ce 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -47,15 +47,6 @@ struct ipc_proc_iface {
int (*show)(struct seq_file *, void *);
};
-struct ipc_namespace init_ipc_ns = {
- .kref = {
- .refcount = ATOMIC_INIT(2),
- },
-};
-
-atomic_t nr_ipc_ns = ATOMIC_INIT(1);
-
-
#ifdef CONFIG_MEMORY_HOTPLUG
static void ipc_memory_notifier(struct work_struct *work)
diff --git a/ipc/util.h b/ipc/util.h
index 3646b45..52755c1 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -20,6 +20,13 @@ void shm_init (void);
struct ipc_namespace;
+#ifdef CONFIG_POSIX_MQUEUE
+void mq_exit_ns(struct ipc_namespace *ns);
+#else
+#define mq_exit_ns(ns)
+#endif
+
+#ifdef CONFIG_SYSVIPC
void sem_init_ns(struct ipc_namespace *ns);
void msg_init_ns(struct ipc_namespace *ns);
void shm_init_ns(struct ipc_namespace *ns);
@@ -27,6 +34,14 @@ void shm_init_ns(struct ipc_namespace *ns);
void sem_exit_ns(struct ipc_namespace *ns);
void msg_exit_ns(struct ipc_namespace *ns);
void shm_exit_ns(struct ipc_namespace *ns);
+#else
+#define sem_init_ns(ns)
+#define msg_init_ns(ns)
+#define shm_init_ns(ns)
+#define sem_exit_ns(ns)
+#define msg_exit_ns(ns)
+#define shm_exit_ns(ns)
+#endif
/*
* Structure that holds the parameters needed by the ipc operations
--
1.5.4.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* [RFC PATCH 2/2] ipc namespaces: implement support for posix msqueues
[not found] ` <20081215233747.GA27553-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-12-15 23:38 ` [RFC PATCH 1/2] mqueue ns: move mqueue_mnt into struct ipc_namespace Serge E. Hallyn
@ 2008-12-15 23:38 ` Serge E. Hallyn
2008-12-16 8:11 ` [RFC patch 0/2] posix mqueue namespace (v11) Cedric Le Goater
2 siblings, 0 replies; 5+ messages in thread
From: Serge E. Hallyn @ 2008-12-15 23:38 UTC (permalink / raw)
To: Linux Containers
Implement multiple mounts of the mqueue file system, and
link it to usage of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When
a user does clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the
unshare will cause an internal mount of a new mqueuefs sb
linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he
mounts the mqueuefs superblock.
Posix message queues can be worked with both through the
mq_* system calls (see mq_overview(7)), and through the VFS
through the mqueue mount. Any usage of mq_open() and friends
will work with the acting task's ipc namespace. Any actions
through the VFS will work with the mqueuefs in which the
file was created. So if a user doesn't remount mqueuefs
after unshare(CLONE_NEWIPC), mq_open("/ab") will not be
reflected in "ls /dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with
a new ipcns, ipcns:2, and then task a is the last task in
ipc_ns:1 to exit, then (1) ipc_ns:1 will be freed, (2) it's
superblock will live on until task b umounts the corresponding
mqueuefs, and vfs actions will continue to succeed, but (3)
sb->s_fs_info will be NULL for the sb corresponding to the
deceased ipc_ns:1.
Largely based on previous version by Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
and Nadia Derbey <Nadia.Derbey-6ktuUTfB/bM@public.gmane.org>.
Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
include/linux/ipc_namespace.h | 16 ++---
ipc/mqueue.c | 150 +++++++++++++++++++++++++++++++++--------
ipc/msgutil.c | 8 +--
ipc/namespace.c | 25 +++++--
ipc/util.h | 6 +-
5 files changed, 154 insertions(+), 51 deletions(-)
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 532598f..74f1ae2 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -25,7 +25,7 @@ struct ipc_ids {
};
struct ipc_namespace {
- struct kref kref;
+ atomic_t count;
struct ipc_ids ids[3];
int sem_ctls[4];
@@ -56,6 +56,7 @@ struct ipc_namespace {
extern struct ipc_namespace init_ipc_ns;
extern atomic_t nr_ipc_ns;
+extern spinlock_t mq_lock;
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
#define INIT_IPC_NS(ns) .ns = &init_ipc_ns,
#else
@@ -75,18 +76,18 @@ extern int ipcns_notify(unsigned long);
#endif /* CONFIG_SYSVIPC */
#ifdef CONFIG_POSIX_MQUEUE
-extern void mq_init_ns(struct ipc_namespace *ns);
+extern int mq_init_ns(struct ipc_namespace *ns);
/* default values */
#define DFLT_QUEUESMAX 256 /* max number of message queues */
#define DFLT_MSGMAX 10 /* max number of messages in each queue */
#define HARD_MSGMAX (131072/sizeof(void *))
#define DFLT_MSGSIZEMAX 8192 /* max message size */
#else
-#define mq_init_ns(ns)
+#define mq_init_ns(ns) (0)
#endif
#if defined(CONFIG_IPC_NS)
-extern void free_ipc_ns(struct kref *kref);
+extern void free_ipc_ns(struct ipc_namespace *ns);
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
struct ipc_namespace *ns);
extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
@@ -96,14 +97,11 @@ extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
if (ns)
- kref_get(&ns->kref);
+ atomic_inc(&ns->count);
return ns;
}
-static inline void put_ipc_ns(struct ipc_namespace *ns)
-{
- kref_put(&ns->kref, free_ipc_ns);
-}
+extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
struct ipc_namespace *ns)
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 01d64a0..de31ef7 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -88,7 +88,6 @@ static const struct file_operations mqueue_file_operations;
static struct super_operations mqueue_super_ops;
static void remove_notification(struct mqueue_inode_info *info);
-static spinlock_t mq_lock;
static struct kmem_cache *mqueue_inode_cachep;
static struct ctl_table_header * mq_sysctl_table;
@@ -98,25 +97,40 @@ static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
return container_of(inode, struct mqueue_inode_info, vfs_inode);
}
-void mq_init_ns(struct ipc_namespace *ns) {
- ns->mq_queues_count = 0;
- ns->mq_queues_max = DFLT_QUEUESMAX;
- ns->mq_msg_max = DFLT_MSGMAX;
- ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
- ns->mq_mnt = mntget(init_ipc_ns.mq_mnt);
+/*
+ * This routine should be called with the mq_lock held.
+ */
+static inline struct ipc_namespace *__get_ns_from_ino(struct inode *inode)
+{
+ return get_ipc_ns(inode->i_sb->s_fs_info);
}
-void mq_exit_ns(struct ipc_namespace *ns) {
- /* will need to clear out ns->mq_mnt->mnt_sb->s_fs_info here */
- mntput(ns->mq_mnt);
+static inline struct ipc_namespace *get_ns_from_ino(struct inode *inode)
+{
+ struct ipc_namespace *ns;
+
+ spin_lock(&mq_lock);
+ ns = __get_ns_from_ino(inode);
+ spin_unlock(&mq_lock);
+ return ns;
+}
+
+static inline struct ipc_namespace *get_ns_from_sb(struct super_block *sb)
+{
+ struct ipc_namespace *ns;
+
+ spin_lock(&mq_lock);
+ ns = get_ipc_ns(sb->s_fs_info);
+ spin_unlock(&mq_lock);
+ return ns;
}
-static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
- struct mq_attr *attr)
+static struct inode *mqueue_get_inode(struct super_block *sb,
+ struct ipc_namespace *ipc_ns, int mode,
+ struct mq_attr *attr)
{
struct user_struct *u = current_user();
struct inode *inode;
- struct ipc_namespace *ipc_ns = &init_ipc_ns;
inode = new_inode(sb);
if (inode) {
@@ -192,30 +206,76 @@ out_inode:
static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
+ struct ipc_namespace *ns = data;
+ int error = 0;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = MQUEUE_MAGIC;
sb->s_op = &mqueue_super_ops;
- inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
- if (!inode)
- return -ENOMEM;
+ inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
+ NULL);
+ if (!inode) {
+ error = -ENOMEM;
+ goto out;
+ }
sb->s_root = d_alloc_root(inode);
if (!sb->s_root) {
iput(inode);
- return -ENOMEM;
+ error = -ENOMEM;
}
- return 0;
+out:
+ return error;
+}
+
+static int compare_sb_single_ns(struct super_block *sb, void *data)
+{
+ return sb->s_fs_info == data;
+}
+
+static int set_sb_single_ns(struct super_block *sb, void *data)
+{
+ sb->s_fs_info = data;
+ return set_anon_super(sb, NULL);
+}
+
+static int get_sb_single_ns(struct file_system_type *fs_type,
+ int flags, void *data,
+ int (*fill_super)(struct super_block *, void *, int),
+ struct vfsmount *mnt)
+{
+ struct super_block *s;
+ int error;
+
+ s = sget(fs_type, compare_sb_single_ns, set_sb_single_ns, data);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ if (!s->s_root) {
+ s->s_flags = flags;
+ error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
+ if (error) {
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ return error;
+ }
+ s->s_flags |= MS_ACTIVE;
+ }
+ do_remount_sb(s, flags, data, 0);
+ return simple_set_mnt(mnt, s);
}
static int mqueue_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data, struct vfsmount *mnt)
{
- return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt);
+ if (flags & MS_KERNMOUNT)
+ return get_sb_single_ns(fs_type, flags, data,
+ mqueue_fill_super, mnt);
+ return get_sb_single_ns(fs_type, flags, current->nsproxy->ipc_ns,
+ mqueue_fill_super, mnt);
}
static void init_once(void *foo)
@@ -246,12 +306,13 @@ static void mqueue_delete_inode(struct inode *inode)
struct user_struct *user;
unsigned long mq_bytes;
int i;
- struct ipc_namespace *ipc_ns = &init_ipc_ns;
+ struct ipc_namespace *ipc_ns;
if (S_ISDIR(inode->i_mode)) {
clear_inode(inode);
return;
}
+ ipc_ns = get_ns_from_ino(inode);
info = MQUEUE_I(inode);
spin_lock(&info->lock);
for (i = 0; i < info->attr.mq_curmsgs; i++)
@@ -267,10 +328,12 @@ static void mqueue_delete_inode(struct inode *inode)
if (user) {
spin_lock(&mq_lock);
user->mq_bytes -= mq_bytes;
- ipc_ns->mq_queues_count--;
+ if (ipc_ns)
+ ipc_ns->mq_queues_count--;
spin_unlock(&mq_lock);
free_uid(user);
}
+ put_ipc_ns(ipc_ns);
}
static int mqueue_create(struct inode *dir, struct dentry *dentry,
@@ -279,9 +342,14 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
struct inode *inode;
struct mq_attr *attr = dentry->d_fsdata;
int error;
- struct ipc_namespace *ipc_ns = &init_ipc_ns;
+ struct ipc_namespace *ipc_ns;
spin_lock(&mq_lock);
+ ipc_ns = __get_ns_from_ino(dir);
+ if (!ipc_ns) {
+ error = -EACCES;
+ goto out_lock;
+ }
if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
!capable(CAP_SYS_RESOURCE)) {
error = -ENOSPC;
@@ -290,7 +358,7 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
ipc_ns->mq_queues_count++;
spin_unlock(&mq_lock);
- inode = mqueue_get_inode(dir->i_sb, mode, attr);
+ inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
if (!inode) {
error = -ENOMEM;
spin_lock(&mq_lock);
@@ -298,6 +366,7 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
goto out_lock;
}
+ put_ipc_ns(ipc_ns);
dir->i_size += DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
@@ -306,6 +375,7 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
return 0;
out_lock:
spin_unlock(&mq_lock);
+ put_ipc_ns(ipc_ns);
return error;
}
@@ -673,7 +743,7 @@ asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
struct file *filp;
char *name;
int fd, error;
- struct ipc_namespace *ipc_ns = &init_ipc_ns;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
error = audit_mq_open(oflag, mode, u_attr);
if (error != 0)
@@ -741,7 +811,7 @@ asmlinkage long sys_mq_unlink(const char __user *u_name)
char *name;
struct dentry *dentry;
struct inode *inode = NULL;
- struct ipc_namespace *ipc_ns = &init_ipc_ns;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
name = getname(u_name);
if (IS_ERR(name))
@@ -1212,6 +1282,29 @@ static struct file_system_type mqueue_fs_type = {
.kill_sb = kill_litter_super,
};
+int mq_init_ns(struct ipc_namespace *ns)
+{
+ ns->mq_queues_count = 0;
+ ns->mq_queues_max = DFLT_QUEUESMAX;
+ ns->mq_msg_max = DFLT_MSGMAX;
+ ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+
+ ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
+ if (IS_ERR(ns->mq_mnt))
+ return PTR_ERR(ns->mq_mnt);
+ return 0;
+}
+
+void mq_clear_sbinfo(struct ipc_namespace *ns)
+{
+ ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+}
+
+void mq_put_mnt(struct ipc_namespace *ns)
+{
+ mntput(ns->mq_mnt);
+}
+
static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = MAX_MSGMAX;
@@ -1283,15 +1376,14 @@ static int __init init_mqueue_fs(void)
if (error)
goto out_sysctl;
- init_ipc_ns.mq_mnt = kern_mount(&mqueue_fs_type);
+ spin_lock_init(&mq_lock);
+
+ init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
if (IS_ERR(init_ipc_ns.mq_mnt)) {
error = PTR_ERR(init_ipc_ns.mq_mnt);
goto out_filesystem;
}
- /* internal initialization - not common for vfs */
- spin_lock_init(&mq_lock);
-
return 0;
out_filesystem:
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index c197cd1..21475b0 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -18,18 +18,16 @@
#include "util.h"
+spinlock_t mq_lock;
+
/*
* The next 2 defines are here bc this is the only file
* compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
* and not CONFIG_IPC_NS.
*/
struct ipc_namespace init_ipc_ns = {
- .kref = {
- .refcount = ATOMIC_INIT(2),
- },
+ .count = ATOMIC_INIT(2),
#ifdef CONFIG_POSIX_MQUEUE
- .mq_mnt = NULL,
- .mq_queues_count = 0,
.mq_queues_max = DFLT_QUEUESMAX,
.mq_msg_max = DFLT_MSGMAX,
.mq_msgsize_max = DFLT_MSGSIZEMAX,
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 4b4dc6d..a4f36ba 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -9,23 +9,31 @@
#include <linux/rcupdate.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
#include "util.h"
static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
{
struct ipc_namespace *ns;
+ int err;
ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
if (ns == NULL)
return ERR_PTR(-ENOMEM);
+ atomic_set(&ns->count, 1);
+ err = mq_init_ns(ns);
+ if (err) {
+ kfree(ns);
+ return ERR_PTR(err);
+ }
atomic_inc(&nr_ipc_ns);
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
- mq_init_ns(ns);
/*
* msgmni has already been computed for the new ipc ns.
@@ -35,7 +43,6 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
ipcns_notify(IPCNS_CREATED);
register_ipcns_notifier(ns);
- kref_init(&ns->kref);
return ns;
}
@@ -85,11 +92,18 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
up_write(&ids->rw_mutex);
}
-void free_ipc_ns(struct kref *kref)
+void put_ipc_ns(struct ipc_namespace *ns)
{
- struct ipc_namespace *ns;
+ if (ns && atomic_dec_and_lock(&ns->count, &mq_lock)) {
+ mq_clear_sbinfo(ns);
+ spin_unlock(&mq_lock);
+ mq_put_mnt(ns);
+ free_ipc_ns(ns);
+ }
+}
- ns = container_of(kref, struct ipc_namespace, kref);
+void free_ipc_ns(struct ipc_namespace *ns)
+{
/*
* Unregistering the hotplug notifier at the beginning guarantees
* that the ipc namespace won't be freed while we are inside the
@@ -102,7 +116,6 @@ void free_ipc_ns(struct kref *kref)
sem_exit_ns(ns);
msg_exit_ns(ns);
shm_exit_ns(ns);
- mq_exit_ns(ns);
kfree(ns);
atomic_dec(&nr_ipc_ns);
diff --git a/ipc/util.h b/ipc/util.h
index 52755c1..b4d213f 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -21,9 +21,11 @@ void shm_init (void);
struct ipc_namespace;
#ifdef CONFIG_POSIX_MQUEUE
-void mq_exit_ns(struct ipc_namespace *ns);
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
#else
-#define mq_exit_ns(ns)
+#define mq_clear_sbinfo(ns)
+#define mq_put_mnt(ns)
#endif
#ifdef CONFIG_SYSVIPC
--
1.5.4.3
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