Messages in this thread | | | From | Andrey Mirkin <> | Subject | Re: [PATCH 4/9] Introduce container dump function | Date | Wed, 3 Sep 2008 18:45:37 +0400 |
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On Wednesday 03 September 2008 18:23 Serge E. Hallyn wrote: > Quoting Andrey Mirkin (major@openvz.org): > > Actually right now we are going to dump only one process. > > Function for dumping head of image file are added. > > > > Signed-off-by: Andrey Mirkin <major@openvz.org> > > --- > > cpt/Makefile | 2 +- > > cpt/checkpoint.c | 74 > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++ cpt/cpt.h | > > 3 ++ > > cpt/sys.c | 3 +- > > kernel/fork.c | 2 + > > 5 files changed, 82 insertions(+), 2 deletions(-) > > create mode 100644 cpt/checkpoint.c > > > > diff --git a/cpt/Makefile b/cpt/Makefile > > index bfe75d5..173346b 100644 > > --- a/cpt/Makefile > > +++ b/cpt/Makefile > > @@ -2,4 +2,4 @@ obj-y += sys_core.o > > > > obj-$(CONFIG_CHECKPOINT) += cptrst.o > > > > -cptrst-objs := sys.o > > +cptrst-objs := sys.o checkpoint.o > > diff --git a/cpt/checkpoint.c b/cpt/checkpoint.c > > new file mode 100644 > > index 0000000..b4d9686 > > --- /dev/null > > +++ b/cpt/checkpoint.c > > @@ -0,0 +1,74 @@ > > +/* > > + * Copyright (C) 2008 Parallels, Inc. > > + * > > + * Author: Andrey Mirkin <major@openvz.org> > > + * > > + * This program is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU General Public License as > > + * published by the Free Software Foundation, version 2 of the > > + * License. > > + * > > + */ > > + > > +#include <linux/sched.h> > > +#include <linux/fs.h> > > +#include <linux/file.h> > > +#include <linux/version.h> > > + > > +#include "cpt.h" > > + > > +static int cpt_write_head(struct cpt_context *ctx) > > +{ > > + struct cpt_head hdr; > > + > > + memset(&hdr, 0, sizeof(hdr)); > > + hdr.cpt_signature[0] = CPT_SIGNATURE0; > > + hdr.cpt_signature[1] = CPT_SIGNATURE1; > > + hdr.cpt_signature[2] = CPT_SIGNATURE2; > > + hdr.cpt_signature[3] = CPT_SIGNATURE3; > > + hdr.cpt_hdrlen = sizeof(hdr); > > + hdr.cpt_image_major = (LINUX_VERSION_CODE >> 16) & 0xff; > > + hdr.cpt_image_minor = (LINUX_VERSION_CODE >> 8) & 0xff; > > + hdr.cpt_image_sublevel = (LINUX_VERSION_CODE) & 0xff; > > + hdr.cpt_image_extra = 0; > > +#if defined(CONFIG_X86_32) > > + hdr.cpt_arch = CPT_ARCH_I386; > > +#else > > +#error Arch is not supported > > +#endif > > + return ctx->write(&hdr, sizeof(hdr), ctx); > > +} > > + > > +int dump_container(struct cpt_context *ctx) > > +{ > > + int err; > > + struct task_struct *root; > > + > > + read_lock(&tasklist_lock); > > + root = find_task_by_vpid(ctx->pid); > > + if (root) > > + get_task_struct(root); > > + read_unlock(&tasklist_lock); > > + > > + err = -ESRCH; > > + if (!root) { > > + eprintk("can not find root task\n"); > > + return err; > > + } > > + ctx->nsproxy = root->nsproxy; > > + if (!ctx->nsproxy) { > > + eprintk("nsproxy is null\n"); > > + goto out; > > + } > > The get_task_struct() above won't pin the tsk->nsproxy > though, will it? So should you be doing a > rcu_read_lock(); > nsproxy = get_task_nsproxy(root); > rcu_read_unlock(); > to make sure the nsproxy doesn't disappear out from under > you? >
You right here, will fix it in next version.
Thanks, Andrey
> > > + err = cpt_write_head(ctx); > > + > > + /* Dump task here */ > > + if (!err) > > + err = -ENOSYS; > > + > > +out: > > + ctx->nsproxy = NULL; > > + put_task_struct(root); > > + return err; > > +} > > diff --git a/cpt/cpt.h b/cpt/cpt.h > > index 607ac1b..b421a11 100644 > > --- a/cpt/cpt.h > > +++ b/cpt/cpt.h > > @@ -33,6 +33,7 @@ typedef struct cpt_context > > int refcount; > > int ctx_state; > > struct semaphore main_sem; > > + struct nsproxy *nsproxy; > > > > int errno; > > > > @@ -54,3 +55,5 @@ extern int debug_level; > > > > #define eprintk(a...) cpt_printk(1, "CPT ERR: " a) > > #define dprintk(a...) cpt_printk(1, "CPT DBG: " a) > > + > > +int dump_container(struct cpt_context *ctx); > > diff --git a/cpt/sys.c b/cpt/sys.c > > index 8334c4c..6801c22 100644 > > --- a/cpt/sys.c > > +++ b/cpt/sys.c > > @@ -109,9 +109,10 @@ static int checkpoint(pid_t pid, int fd, unsigned > > long flags) > > > > ctx->file = file; > > ctx->ctx_state = CPT_CTX_DUMPING; > > + ctx->pid = pid; > > > > /* checkpoint */ > > - err = -ENOSYS; > > + err = dump_container(ctx); > > > > context_put(ctx); > > > > diff --git a/kernel/fork.c b/kernel/fork.c > > index 52b5037..f38b43d 100644 > > --- a/kernel/fork.c > > +++ b/kernel/fork.c > > @@ -77,6 +77,7 @@ int max_threads; /* tunable limit on nr_threads */ > > DEFINE_PER_CPU(unsigned long, process_counts) = 0; > > > > __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */ > > +EXPORT_SYMBOL(tasklist_lock); > > > > int nr_processes(void) > > { > > @@ -153,6 +154,7 @@ void __put_task_struct(struct task_struct *tsk) > > if (!profile_handoff_task(tsk)) > > free_task(tsk); > > } > > +EXPORT_SYMBOL(__put_task_struct); > > > > /* > > * macro override instead of weak attribute alias, to workaround > > -- > > 1.5.6 > > > > _______________________________________________ > > Containers mailing list > > Containers@lists.linux-foundation.org > > https://lists.linux-foundation.org/mailman/listinfo/containers > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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