6546bc4279
The enhancement as asked for by Yasunori: if msgmni is set to a negative value, register it back into the ipcns notifier chain. A new interface has been added to the notification mechanism: notifier_chain_cond_register() registers a notifier block only if not already registered. With that new interface we avoid taking care of the states changes in procfs. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
102 lines
2.2 KiB
C
102 lines
2.2 KiB
C
#ifndef __IPC_NAMESPACE_H__
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#define __IPC_NAMESPACE_H__
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#include <linux/err.h>
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#include <linux/idr.h>
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#include <linux/rwsem.h>
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#include <linux/notifier.h>
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/*
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* ipc namespace events
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*/
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#define IPCNS_MEMCHANGED 0x00000001 /* Notify lowmem size changed */
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#define IPCNS_CREATED 0x00000002 /* Notify new ipc namespace created */
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#define IPCNS_REMOVED 0x00000003 /* Notify ipc namespace removed */
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#define IPCNS_CALLBACK_PRI 0
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struct ipc_ids {
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int in_use;
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unsigned short seq;
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unsigned short seq_max;
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struct rw_semaphore rw_mutex;
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struct idr ipcs_idr;
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};
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struct ipc_namespace {
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struct kref kref;
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struct ipc_ids ids[3];
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int sem_ctls[4];
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int used_sems;
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int msg_ctlmax;
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int msg_ctlmnb;
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int msg_ctlmni;
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atomic_t msg_bytes;
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atomic_t msg_hdrs;
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size_t shm_ctlmax;
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size_t shm_ctlall;
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int shm_ctlmni;
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int shm_tot;
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struct notifier_block ipcns_nb;
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};
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extern struct ipc_namespace init_ipc_ns;
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extern atomic_t nr_ipc_ns;
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#ifdef CONFIG_SYSVIPC
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#define INIT_IPC_NS(ns) .ns = &init_ipc_ns,
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extern int register_ipcns_notifier(struct ipc_namespace *);
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extern int cond_register_ipcns_notifier(struct ipc_namespace *);
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extern int unregister_ipcns_notifier(struct ipc_namespace *);
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extern int ipcns_notify(unsigned long);
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#else /* CONFIG_SYSVIPC */
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#define INIT_IPC_NS(ns)
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#endif /* CONFIG_SYSVIPC */
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#if defined(CONFIG_SYSVIPC) && defined(CONFIG_IPC_NS)
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extern void free_ipc_ns(struct kref *kref);
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extern struct ipc_namespace *copy_ipcs(unsigned long flags,
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struct ipc_namespace *ns);
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extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
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void (*free)(struct ipc_namespace *,
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struct kern_ipc_perm *));
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static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
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{
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if (ns)
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kref_get(&ns->kref);
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return ns;
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}
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static inline void put_ipc_ns(struct ipc_namespace *ns)
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{
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kref_put(&ns->kref, free_ipc_ns);
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}
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#else
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static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
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struct ipc_namespace *ns)
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{
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if (flags & CLONE_NEWIPC)
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return ERR_PTR(-EINVAL);
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return ns;
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}
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static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
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{
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return ns;
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}
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static inline void put_ipc_ns(struct ipc_namespace *ns)
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{
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}
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#endif
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#endif
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