Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids' are dynamically allocated for each icp_namespace as the ipc_namespace itself (for the init namespace, they are initialized with pointers to static variables instead) It is so for historical reason: in fact, before the use of idr to store the ipcs, the ipcs were stored in tables of variable length, depending of the maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any cases for each new ipc_namespace, there is no gain of memory in having them allocated separately of the struct ipc_namespace. This patch proposes to make this table static in the struct ipc_namespace. Thus, we can allocate all in once and get rid of all the code needed to allocate and free these ipc_ids separately. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
56 lines
1 KiB
C
56 lines
1 KiB
C
/*
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* linux/ipc/namespace.c
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* Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc.
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*/
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#include <linux/ipc.h>
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#include <linux/msg.h>
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#include <linux/ipc_namespace.h>
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#include <linux/rcupdate.h>
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#include <linux/nsproxy.h>
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#include <linux/slab.h>
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#include "util.h"
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static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
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{
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struct ipc_namespace *ns;
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ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
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if (ns == NULL)
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return ERR_PTR(-ENOMEM);
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sem_init_ns(ns);
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msg_init_ns(ns);
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shm_init_ns(ns);
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kref_init(&ns->kref);
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return ns;
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}
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struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
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{
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struct ipc_namespace *new_ns;
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BUG_ON(!ns);
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get_ipc_ns(ns);
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if (!(flags & CLONE_NEWIPC))
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return ns;
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new_ns = clone_ipc_ns(ns);
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put_ipc_ns(ns);
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return new_ns;
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}
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void free_ipc_ns(struct kref *kref)
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{
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struct ipc_namespace *ns;
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ns = container_of(kref, struct ipc_namespace, kref);
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sem_exit_ns(ns);
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msg_exit_ns(ns);
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shm_exit_ns(ns);
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kfree(ns);
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}
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