Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756330AbYHUDId (ORCPT ); Wed, 20 Aug 2008 23:08:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754672AbYHUDHm (ORCPT ); Wed, 20 Aug 2008 23:07:42 -0400 Received: from serrano.cc.columbia.edu ([128.59.29.6]:54932 "EHLO serrano.cc.columbia.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754665AbYHUDHk (ORCPT ); Wed, 20 Aug 2008 23:07:40 -0400 Date: Wed, 20 Aug 2008 23:04:13 -0400 (EDT) From: Oren Laadan X-X-Sender: orenl@takamine.ncl.cs.columbia.edu To: dave@linux.vnet.ibm.com cc: arnd@arndb.de, jeremy@goop.org, linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org Subject: [RFC v2][PATCH 2/9] General infrastructure for checkpoint restart In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-No-Spam-Score: Local Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 20720 Lines: 864 Add those interfaces, as well as helpers needed to easily manage the file format. The code is roughly broken out as follows: ckpt/sys.c - user/kernel data transfer, as well as setup of the checkpoint/restart context (a per-checkpoint data structure for housekeeping) ckpt/checkpoint.c - output wrappers and basic checkpoint handling ckpt/restart.c - input wrappers and basic restart handling Patches to add the per-architecture support as well as the actual work to do the memory checkpoint follow in subsequent patches. Signed-off-by: Oren Laadan --- Makefile | 2 +- checkpoint/Makefile | 1 + checkpoint/checkpoint.c | 191 +++++++++++++++++++++++++++++++++++++++ checkpoint/ckpt.h | 71 +++++++++++++++ checkpoint/ckpt_hdr.h | 86 ++++++++++++++++++ checkpoint/restart.c | 199 +++++++++++++++++++++++++++++++++++++++++ checkpoint/sys.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 776 insertions(+), 1 deletions(-) create mode 100644 checkpoint/Makefile create mode 100644 checkpoint/checkpoint.c create mode 100644 checkpoint/ckpt.h create mode 100644 checkpoint/ckpt_hdr.h create mode 100644 checkpoint/restart.c create mode 100644 checkpoint/sys.c diff --git a/Makefile b/Makefile index f3e2065..584c8f9 100644 --- a/Makefile +++ b/Makefile @@ -619,7 +619,7 @@ export mod_strip_cmd ifeq ($(KBUILD_EXTMOD),) -core-y += kernel/ mm/ fs/ ipc/ security/ crypto/ block/ +core-y += kernel/ mm/ fs/ ipc/ security/ crypto/ block/ checkpoint/ vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \ $(core-y) $(core-m) $(drivers-y) $(drivers-m) \ diff --git a/checkpoint/Makefile b/checkpoint/Makefile new file mode 100644 index 0000000..d129878 --- /dev/null +++ b/checkpoint/Makefile @@ -0,0 +1 @@ +obj-y += sys.o checkpoint.o restart.o diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c new file mode 100644 index 0000000..25343f5 --- /dev/null +++ b/checkpoint/checkpoint.c @@ -0,0 +1,191 @@ +/* + * Checkpoint logic and helpers + * + * Copyright (C) 2008 Oren Laadan + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ckpt.h" +#include "ckpt_hdr.h" + +/** + * cr_fill_fname - return pathname of a given file + * @file: file pointer + * @buf: buffer for pathname + * @n: buffer length (in) and pathname length (out) + */ +char *cr_fill_fname(struct path *path, struct path *root, char *buf, int *n) +{ + char *fname; + + BUG_ON(!buf); + fname = __d_path(path, root, buf, *n); + if (!IS_ERR(fname)) + *n = (buf + (*n) - fname); + return fname; +} + +/** + * cr_write_obj - write a record described by a cr_hdr + * @ctx: checkpoint context + * @h: record descriptor + * @buf: record buffer + */ +int cr_write_obj(struct cr_ctx *ctx, struct cr_hdr *h, void *buf) +{ + int ret; + + if ((ret = cr_kwrite(ctx, h, sizeof(*h))) < 0) + return ret; + return cr_kwrite(ctx, buf, h->len); +} + +/** + * cr_write_str - write a string record + * @ctx: checkpoint context + * @str: string buffer + * @n: string length + */ +int cr_write_str(struct cr_ctx *ctx, char *str, int n) +{ + struct cr_hdr h; + + h.type = CR_HDR_STR; + h.len = n; + h.ptag = 0; + + return cr_write_obj(ctx, &h, str); +} + +/* write the checkpoint header */ +static int cr_write_hdr(struct cr_ctx *ctx) +{ + struct cr_hdr h; + struct cr_hdr_head *hh = ctx->hbuf; + struct new_utsname *uts; + struct timeval ktv; + + h.type = CR_HDR_HEAD; + h.len = sizeof(*hh); + h.ptag = 0; + + do_gettimeofday(&ktv); + + hh->magic = CR_MAGIC_HEAD; + hh->major = (LINUX_VERSION_CODE >> 16) & 0xff; + hh->minor = (LINUX_VERSION_CODE >> 8) & 0xff; + hh->patch = (LINUX_VERSION_CODE) & 0xff; + + hh->rev = CR_VERSION; + + hh->flags = ctx->flags; + hh->time = ktv.tv_sec; + + uts = utsname(); + memcpy(hh->release, uts->release, __NEW_UTS_LEN); + memcpy(hh->version, uts->version, __NEW_UTS_LEN); + memcpy(hh->machine, uts->machine, __NEW_UTS_LEN); + + return cr_write_obj(ctx, &h, hh); +} + +/* write the checkpoint trailer */ +static int cr_write_tail(struct cr_ctx *ctx) +{ + struct cr_hdr h; + struct cr_hdr_tail *hh = ctx->hbuf; + + h.type = CR_HDR_TAIL; + h.len = sizeof(*hh); + h.ptag = 0; + + hh->magic = CR_MAGIC_TAIL; + hh->cksum = 1; /* TBD ... */ + + return cr_write_obj(ctx, &h, hh); +} + +/* dump the task_struct of a given task */ +static int cr_write_task_struct(struct cr_ctx *ctx, struct task_struct *t) +{ + struct cr_hdr h; + struct cr_hdr_task *hh = ctx->hbuf; + + h.type = CR_HDR_TASK; + h.len = sizeof(*hh); + h.ptag = 0; + + hh->state = t->state; + hh->exit_state = t->exit_state; + hh->exit_code = t->exit_code; + hh->exit_signal = t->exit_signal; + + hh->utime = t->utime; + hh->stime = t->stime; + hh->utimescaled = t->utimescaled; + hh->stimescaled = t->stimescaled; + hh->gtime = t->gtime; + hh->prev_utime = t->prev_utime; + hh->prev_stime = t->prev_stime; + hh->nvcsw = t->nvcsw; + hh->nivcsw = t->nivcsw; + hh->start_time_sec = t->start_time.tv_sec; + hh->start_time_nsec = t->start_time.tv_nsec; + hh->real_start_time_sec = t->real_start_time.tv_sec; + hh->real_start_time_nsec = t->real_start_time.tv_nsec; + hh->min_flt = t->min_flt; + hh->maj_flt = t->maj_flt; + + hh->task_comm_len = TASK_COMM_LEN; + memcpy(hh->comm, t->comm, TASK_COMM_LEN); + + return cr_write_obj(ctx, &h, hh); +} + +/* dump the entire state of a given task */ +static int cr_write_task(struct cr_ctx *ctx, struct task_struct *t) +{ + int ret ; + + if (t->state == TASK_DEAD) { + pr_warning("CR: task may not be in state TASK_DEAD\n"); + return -EAGAIN; + } + + ret = cr_write_task_struct(ctx, t); + cr_debug("ret %d\n", ret); + + return ret; +} + +int do_checkpoint(struct cr_ctx *ctx) +{ + int ret; + + /* FIX: need to test whether container is checkpointable */ + + ret = cr_write_hdr(ctx); + if (!ret) + ret = cr_write_task(ctx, current); + if (!ret) + ret = cr_write_tail(ctx); + + /* on success, return (unique) checkpoint identifier */ + if (!ret) + ret = ctx->crid; + + return ret; +} diff --git a/checkpoint/ckpt.h b/checkpoint/ckpt.h new file mode 100644 index 0000000..7ecafb3 --- /dev/null +++ b/checkpoint/ckpt.h @@ -0,0 +1,71 @@ +#ifndef _CHECKPOINT_CKPT_H_ +#define _CHECKPOINT_CKPT_H_ +/* + * Generic container checkpoint-restart + * + * Copyright (C) 2008 Oren Laadan + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +#include +#include + +#define CR_VERSION 1 + +struct cr_ctx { + pid_t pid; /* container identifier */ + int crid; /* unique checkpoint id */ + + unsigned long flags; + unsigned long oflags; /* restart: old flags */ + + struct file *file; + int total; /* total read/written */ + + void *tbuf; /* temp: to avoid many alloc/dealloc */ + void *hbuf; /* header: to avoid many alloc/dealloc */ + int hpos; + + struct path *vfsroot; /* container root */ +}; + +/* cr_ctx: flags */ +#define CR_CTX_CKPT 0x1 +#define CR_CTX_RSTR 0x2 + +/* allocation defaults */ +#define CR_TBUF_ORDER 1 +#define CR_TBUF_TOTAL (PAGE_SIZE << CR_TBUF_ORDER) + +#define CR_HBUF_ORDER 1 +#define CR_HBUF_TOTAL (PAGE_SIZE << CR_HBUF_ORDER) + +char *cr_fill_fname(struct path *path, struct path *root, char *buf, int *n); + +int cr_uwrite(struct cr_ctx *ctx, void *buf, int count); +int cr_kwrite(struct cr_ctx *ctx, void *buf, int count); +int cr_uread(struct cr_ctx *ctx, void *buf, int count); +int cr_kread(struct cr_ctx *ctx, void *buf, int count); + +void *cr_hbuf_get(struct cr_ctx *ctx, int n); +void cr_hbuf_put(struct cr_ctx *ctx, int n); + +struct cr_hdr; + +int cr_write_obj(struct cr_ctx *ctx, struct cr_hdr *h, void *buf); +int cr_write_str(struct cr_ctx *ctx, char *str, int n); + +int cr_read_obj(struct cr_ctx *ctx, struct cr_hdr *h, void *buf, int n); +int cr_read_obj_type(struct cr_ctx *ctx, void *buf, int n, int type); +int cr_read_str(struct cr_ctx *ctx, void *str, int n); + +int do_checkpoint(struct cr_ctx *ctx); +int do_restart(struct cr_ctx *ctx); + +#define cr_debug(fmt, args...) \ + pr_debug("[CR:%s] " fmt, __func__, ## args) + +#endif /* _CHECKPOINT_CKPT_H_ */ diff --git a/checkpoint/ckpt_hdr.h b/checkpoint/ckpt_hdr.h new file mode 100644 index 0000000..a478b7c --- /dev/null +++ b/checkpoint/ckpt_hdr.h @@ -0,0 +1,86 @@ +#ifndef _CHECKPOINT_CKPT_HDR_H_ +#define _CHECKPOINT_CKPT_HDR_H_ +/* + * Generic container checkpoint-restart + * + * Copyright (C) 2008 Oren Laadan + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +#include +#include + +#define CR_MAGIC_HEAD 0x00feed0cc0a2d200LL +#define CR_MAGIC_TAIL 0x002d2a0cc0deef00LL + +/* + * To maintain compatibility between 32-bit and 64-bit architecture flavors, + * keep data 64-bit aligned: use padding for structure members, and use + * __attribute__ ((aligned (8))) for the entire structure. + */ + +/* records: generic header */ + +struct cr_hdr { + __s16 type; + __s16 len; + __u32 ptag; +}; + +enum { + CR_HDR_HEAD = 1, + CR_HDR_STR, + + CR_HDR_TASK = 101, + CR_HDR_THREAD, + CR_HDR_CPU, + + CR_HDR_MM = 201, + CR_HDR_VMA, + CR_HDR_MM_CONTEXT, + + CR_HDR_TAIL = 5001 +}; + +struct cr_hdr_head { + __u64 magic; + + __u16 major; + __u16 minor; + __u16 patch; + __u16 rev; + + __u64 time; /* when checkpoint taken */ + __u64 flags; /* checkpoint options */ + + char release[__NEW_UTS_LEN]; + char version[__NEW_UTS_LEN]; + char machine[__NEW_UTS_LEN]; +} __attribute__ ((aligned (8))); + +struct cr_hdr_tail { + __u64 magic; + __u64 cksum; +} __attribute__ ((aligned (8))); + +struct cr_hdr_task { + __u64 state; + __u32 exit_state; + __u32 exit_code, exit_signal; + + __u64 utime, stime, utimescaled, stimescaled; + __u64 gtime; + __u64 prev_utime, prev_stime; + __u64 nvcsw, nivcsw; + __u64 start_time_sec, start_time_nsec; + __u64 real_start_time_sec, real_start_time_nsec; + __u64 min_flt, maj_flt; + + __s16 task_comm_len; + char comm[TASK_COMM_LEN]; +} __attribute__ ((aligned (8))); + +#endif /* _CHECKPOINT_CKPT_HDR_H_ */ diff --git a/checkpoint/restart.c b/checkpoint/restart.c new file mode 100644 index 0000000..be7d08c --- /dev/null +++ b/checkpoint/restart.c @@ -0,0 +1,199 @@ +/* + * Restart logic and helpers + * + * Copyright (C) 2008 Oren Laadan + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +/* + * During restart the code reads in data from the chekcpoint image into a + * temporary buffer (ctx->hbuf). Because operations can be nested, one + * should call cr_hbuf_get() to reserve space in the buffer, and then + * cr_hbuf_put() when it no longer needs that space + */ + +#include +#include +#include + +#include "ckpt.h" +#include "ckpt_hdr.h" + +/** + * cr_hbuf_get - reserve space on the hbuf + * @ctx: checkpoint context + * @n: number of bytes to reserve + */ +void *cr_hbuf_get(struct cr_ctx *ctx, int n) +{ + void *ptr; + + BUG_ON(ctx->hpos + n > CR_HBUF_TOTAL); + ptr = (void *) (((char *) ctx->hbuf) + ctx->hpos); + ctx->hpos += n; + return ptr; +} + +/** + * cr_hbuf_put - unreserve space on the hbuf + * @ctx: checkpoint context + * @n: number of bytes to reserve + */ +void cr_hbuf_put(struct cr_ctx *ctx, int n) +{ + BUG_ON(ctx->hpos < n); + ctx->hpos -= n; +} + +/** + * cr_read_obj - read a whole record (cr_hdr followed by payload) + * @ctx: checkpoint context + * @h: record descriptor + * @buf: record buffer + * @n: available buffer size + */ +int cr_read_obj(struct cr_ctx *ctx, struct cr_hdr *h, void *buf, int n) +{ + int ret; + + ret = cr_kread(ctx, h, sizeof(*h)); + if (ret < 0) + return ret; + + cr_debug("type %d len %d id %d (%d)\n", h->type, h->len, h->ptag, n); + + if (h->len < 0 || h->len > n) + return -EINVAL; + + return cr_kread(ctx, buf, h->len); +} + +/** + * cr_read_obj_type - read a whole record of expected type + * @ctx: checkpoint context + * @buf: record buffer + * @n: available buffer size + * @type: expected record type + */ +int cr_read_obj_type(struct cr_ctx *ctx, void *buf, int n, int type) +{ + struct cr_hdr h; + int ret; + + ret = cr_read_obj(ctx, &h, buf, n); + if (!ret) + ret = (h.type == type ? h.ptag : -EINVAL); + return ret; +} + +/** + * cr_read_str - read a string record + * @ctx: checkpoint context + * @str: string buffer + * @n: string length + */ +int cr_read_str(struct cr_ctx *ctx, void *str, int n) +{ + return cr_read_obj_type(ctx, str, n, CR_HDR_STR); +} + +/* read the checkpoint header */ +static int cr_read_hdr(struct cr_ctx *ctx) +{ + struct cr_hdr_head *hh = cr_hbuf_get(ctx, sizeof(*hh)); + int ret; + + ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_HEAD); + if (ret < 0) + return ret; + else if (ret != 0) + return -EINVAL; + + if (hh->magic != CR_MAGIC_HEAD || hh->rev != CR_VERSION || + hh->major != ((LINUX_VERSION_CODE >> 16) & 0xff) || + hh->minor != ((LINUX_VERSION_CODE >> 8) & 0xff) || + hh->patch != ((LINUX_VERSION_CODE) & 0xff)) + return -EINVAL; + + if (hh->flags & ~CR_CTX_CKPT) + return -EINVAL; + + ctx->oflags = hh->flags; + + /* FIX: verify compatibility of release, version and machine */ + + cr_hbuf_put(ctx, sizeof(*hh)); + return 0; +} + +/* read the checkpoint trailer */ +static int cr_read_tail(struct cr_ctx *ctx) +{ + struct cr_hdr_tail *hh = cr_hbuf_get(ctx, sizeof(*hh)); + int ret; + + ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_TAIL); + if (ret < 0) + return ret; + else if (ret != 0) + return -EINVAL; + + if (hh->magic != CR_MAGIC_TAIL || hh->cksum != 1) + return -EINVAL; + + cr_hbuf_put(ctx, sizeof(*hh)); + return 0; +} + +/* read the task_struct into the current task */ +static int cr_read_task_struct(struct cr_ctx *ctx) +{ + struct cr_hdr_task *hh = cr_hbuf_get(ctx, sizeof(*hh)); + struct task_struct *t = current; + int ret; + + ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_TASK); + if (ret < 0) + return ret; + else if (ret != 0) + return -EINVAL; + + /* for now, only restore t->comm */ + if (hh->task_comm_len < 0 || hh->task_comm_len > TASK_COMM_LEN) + return -EINVAL; + + /* current should already have correct pid and tgid */ + + memset(t->comm, 0, TASK_COMM_LEN); + memcpy(t->comm, hh->comm, hh->task_comm_len); + + cr_hbuf_put(ctx, sizeof(*hh)); + return 0; +} + +/* read the entire state of the current task */ +static int cr_read_task(struct cr_ctx *ctx) +{ + int ret; + + ret = cr_read_task_struct(ctx); + cr_debug("ret %d\n", ret); + + return ret; +} + +int do_restart(struct cr_ctx *ctx) +{ + int ret; + + ret = cr_read_hdr(ctx); + if (!ret) + ret = cr_read_task(ctx); + if (!ret) + ret = cr_read_tail(ctx); + + return ret; +} diff --git a/checkpoint/sys.c b/checkpoint/sys.c new file mode 100644 index 0000000..2891c48 --- /dev/null +++ b/checkpoint/sys.c @@ -0,0 +1,227 @@ +/* + * Generic container checkpoint-restart + * + * Copyright (C) 2008 Oren Laadan + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +#include +#include +#include +#include +#include + +#include "ckpt.h" + +/* + * helpers to write/read to/from the image file descriptor + * + * cr_uwrite() - write a user-space buffer to the checkpoint image + * cr_kwrite() - write a kernel-space buffer to the checkpoint image + * cr_uread() - read from the checkpoint image to a user-space buffer + * cr_kread() - read from the checkpoint image to a kernel-space buffer + * + */ + +/* (temporarily added file_pos_read() and file_pos_write() because they + * are static in fs/read_write.c... should cleanup and remove later) */ +static inline loff_t file_pos_read(struct file *file) +{ + return file->f_pos; +} + +static inline void file_pos_write(struct file *file, loff_t pos) +{ + file->f_pos = pos; +} + +int cr_uwrite(struct cr_ctx *ctx, void *buf, int count) +{ + struct file *file = ctx->file; + ssize_t nwrite; + int nleft; + + for (nleft = count; nleft; nleft -= nwrite) { + loff_t pos = file_pos_read(file); + nwrite = vfs_write(file, (char __user *) buf, nleft, &pos); + file_pos_write(file, pos); + if (unlikely(nwrite <= 0)) /* zero tolerance */ + return (nwrite ? : -EIO); + buf += nwrite; + } + + ctx->total += count; + return 0; +} + +int cr_kwrite(struct cr_ctx *ctx, void *buf, int count) +{ + mm_segment_t oldfs; + int ret; + + oldfs = get_fs(); + set_fs(KERNEL_DS); + ret = cr_uwrite(ctx, buf, count); + set_fs(oldfs); + + return ret; +} + +int cr_uread(struct cr_ctx *ctx, void *buf, int count) +{ + struct file *file = ctx->file; + ssize_t nread; + int nleft; + + for (nleft = count; nleft; nleft -= nread) { + loff_t pos = file_pos_read(file); + nread = vfs_read(file, (char __user *) buf, nleft, &pos); + file_pos_write(file, pos); + if (unlikely(nread <= 0)) /* zero tolerance */ + return (nread ? : -EIO); + buf += nread; + } + + ctx->total += count; + return 0; +} + +int cr_kread(struct cr_ctx *ctx, void *buf, int count) +{ + mm_segment_t oldfs; + int ret; + + oldfs = get_fs(); + set_fs(KERNEL_DS); + ret = cr_uread(ctx, buf, count); + set_fs(oldfs); + + return ret; +} + + +/* + * helpers to manage CR contexts: allocated for each checkpoint and/or + * restart operation, and persists until the operation is completed. + */ + +static atomic_t cr_ctx_count; /* unique checkpoint identifier */ + +void cr_ctx_free(struct cr_ctx *ctx) +{ + + if (ctx->file) + fput(ctx->file); + if (ctx->vfsroot) + path_put(ctx->vfsroot); + + free_pages((unsigned long) ctx->tbuf, CR_TBUF_ORDER); + free_pages((unsigned long) ctx->hbuf, CR_HBUF_ORDER); + + kfree(ctx); +} + +struct cr_ctx *cr_ctx_alloc(pid_t pid, struct file *file, unsigned long flags) +{ + struct cr_ctx *ctx; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return NULL; + + ctx->tbuf = (void *) __get_free_pages(GFP_KERNEL, CR_TBUF_ORDER); + ctx->hbuf = (void *) __get_free_pages(GFP_KERNEL, CR_HBUF_ORDER); + if (!ctx->tbuf || !ctx->hbuf) + goto nomem; + + ctx->pid = pid; + ctx->flags = flags; + + ctx->file = file; + get_file(file); + + /* assume checkpointer is in container's root vfs */ + ctx->vfsroot = ¤t->fs->root; + path_get(ctx->vfsroot); + + ctx->crid = atomic_inc_return(&cr_ctx_count); + + return ctx; + + nomem: + cr_ctx_free(ctx); + return NULL; +} + +/** + * sys_checkpoint - checkpoint a container + * @pid: pid of the container init(1) process + * @fd: file to which dump the checkpoint image + * @flags: checkpoint operation flags + */ +asmlinkage long sys_checkpoint(pid_t pid, int fd, unsigned long flags) +{ + struct cr_ctx *ctx; + struct file *file; + int fput_needed; + int ret; + + file = fget_light(fd, &fput_needed); + if (!file) + return -EBADF; + + /* no flags for now */ + if (flags) + return -EINVAL; + + ctx = cr_ctx_alloc(pid, file, flags | CR_CTX_CKPT); + if (!ctx) { + fput_light(file, fput_needed); + return -ENOMEM; + } + + ret = do_checkpoint(ctx); + + cr_ctx_free(ctx); + fput_light(file, fput_needed); + + return ret; +} + +/** + * sys_restart - restart a container + * @crid: checkpoint image identifier + * @fd: file from which read the checkpoint image + * @flags: restart operation flags + */ +asmlinkage long sys_restart(int crid, int fd, unsigned long flags) +{ + struct cr_ctx *ctx; + struct file *file; + int fput_needed; + int ret; + + file = fget_light(fd, &fput_needed); + if (!file) + return -EBADF; + + /* no flags for now */ + if (flags) + return -EINVAL; + + ctx = cr_ctx_alloc(crid, file, flags | CR_CTX_RSTR); + if (!ctx) { + fput_light(file, fput_needed); + return -ENOMEM; + } + + ret = do_restart(ctx); + + cr_ctx_free(ctx); + fput_light(file, fput_needed); + + return ret; +} -- 1.5.4.3 -- 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/