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author | 2006-10-02 02:18:06 -0700 | |
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committer | 2006-10-02 07:57:20 -0700 | |
commit | ab516013ad9ca47f1d3a936fa81303bfbf734d52 (patch) | |
tree | 643ea9c4c3d28958cb42dd87b1856f74edd22b11 /include/linux/nsproxy.h | |
parent | [PATCH] make kernel/sysctl.c:_proc_do_string() static (diff) | |
download | linux-ab516013ad9ca47f1d3a936fa81303bfbf734d52.tar.gz linux-ab516013ad9ca47f1d3a936fa81303bfbf734d52.tar.bz2 linux-ab516013ad9ca47f1d3a936fa81303bfbf734d52.zip |
[PATCH] namespaces: add nsproxy
This patch adds a nsproxy structure to the task struct. Later patches will
move the fs namespace pointer into this structure, and introduce a new utsname
namespace into the nsproxy.
The vserver and openvz functionality, then, would be implemented in large part
by virtualizing/isolating more and more resources into namespaces, each
contained in the nsproxy.
[akpm@osdl.org: build fix]
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/nsproxy.h')
-rw-r--r-- | include/linux/nsproxy.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h new file mode 100644 index 000000000000..7bdebfaab6a5 --- /dev/null +++ b/include/linux/nsproxy.h @@ -0,0 +1,45 @@ +#ifndef _LINUX_NSPROXY_H +#define _LINUX_NSPROXY_H + +#include <linux/spinlock.h> +#include <linux/sched.h> + +/* + * A structure to contain pointers to all per-process + * namespaces - fs (mount), uts, network, sysvipc, etc. + * + * 'count' is the number of tasks holding a reference. + * The count for each namespace, then, will be the number + * of nsproxies pointing to it, not the number of tasks. + * + * The nsproxy is shared by tasks which share all namespaces. + * As soon as a single namespace is cloned or unshared, the + * nsproxy is copied. + */ +struct nsproxy { + atomic_t count; + spinlock_t nslock; +}; +extern struct nsproxy init_nsproxy; + +struct nsproxy *dup_namespaces(struct nsproxy *orig); +int copy_namespaces(int flags, struct task_struct *tsk); +void get_task_namespaces(struct task_struct *tsk); +void free_nsproxy(struct nsproxy *ns); + +static inline void put_nsproxy(struct nsproxy *ns) +{ + if (atomic_dec_and_test(&ns->count)) { + free_nsproxy(ns); + } +} + +static inline void exit_task_namespaces(struct task_struct *p) +{ + struct nsproxy *ns = p->nsproxy; + if (ns) { + put_nsproxy(ns); + p->nsproxy = NULL; + } +} +#endif |