Messages in this thread | | | From | Andrey Mirkin <> | Subject | Re: [PATCH 3/9] Introduce context structure needed during checkpointing/restart | Date | Wed, 3 Sep 2008 18:11:45 +0400 |
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On Wednesday 03 September 2008 16:29 Matthieu Fertré wrote: > Andrey Mirkin a écrit : > > Add functions for context allocation/destroy. > > Introduce functions to read/write image. > > Introduce image header and object header. > > > > Signed-off-by: Andrey Mirkin <major@openvz.org> > > --- > > cpt/cpt.h | 37 ++++++++++++++++ > > cpt/cpt_image.h | 63 +++++++++++++++++++++++++++ > > cpt/sys.c | 127 > > +++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, > > 224 insertions(+), 3 deletions(-) > > create mode 100644 cpt/cpt_image.h > > > > diff --git a/cpt/cpt.h b/cpt/cpt.h > > index 381a9bf..607ac1b 100644 > > --- a/cpt/cpt.h > > +++ b/cpt/cpt.h > > @@ -10,6 +10,8 @@ > > * > > */ > > > > +#include "cpt_image.h" > > + > > struct cpt_operations > > { > > struct module * owner; > > @@ -17,3 +19,38 @@ struct cpt_operations > > int (*restart)(int ctid, int fd, unsigned long flags); > > }; > > extern struct cpt_operations cpt_ops; > > + > > +#define CPT_CTX_ERROR -1 > > +#define CPT_CTX_IDLE 0 > > +#define CPT_CTX_DUMPING 1 > > +#define CPT_CTX_UNDUMPING 2 > > Maybe you can define an enum here instead. > > > + > > +typedef struct cpt_context > > +{ > > + pid_t pid; /* should be changed to ctid later */ > > + int ctx_id; /* context id */ > > + struct list_head ctx_list; > > + int refcount; > > + int ctx_state; > > It will be more clear that ctx_state refers to it.
Thanks for the idea with enum, I'll fix it in next version.
Regards, Andrey
> > > + struct semaphore main_sem; > > + > > + int errno; > > + > > + struct file *file; > > + loff_t current_object; > > + > > + struct list_head object_array[CPT_OBJ_MAX]; > > + > > + int (*write)(const void *addr, size_t count, struct cpt_context *ctx); > > + int (*read)(void *addr, size_t count, struct cpt_context *ctx); > > +} cpt_context_t; > > + > > +extern int debug_level; > > + > > +#define cpt_printk(lvl, fmt, args...) do { \ > > + if (lvl <= debug_level) \ > > + printk(fmt, ##args); \ > > + } while (0) > > + > > +#define eprintk(a...) cpt_printk(1, "CPT ERR: " a) > > +#define dprintk(a...) cpt_printk(1, "CPT DBG: " a) > > diff --git a/cpt/cpt_image.h b/cpt/cpt_image.h > > new file mode 100644 > > index 0000000..3d26229 > > --- /dev/null > > +++ b/cpt/cpt_image.h > > @@ -0,0 +1,63 @@ > > +/* > > + * 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. > > + * > > + */ > > + > > +#ifndef __CPT_IMAGE_H_ > > +#define __CPT_IMAGE_H_ 1 > > + > > +enum _cpt_object_type > > +{ > > + CPT_OBJ_TASK = 0, > > + CPT_OBJ_MAX, > > + /* The objects above are stored in memory while checkpointing */ > > + > > + CPT_OBJ_HEAD = 1024, > > +}; > > + > > +enum _cpt_content_type { > > + CPT_CONTENT_VOID, > > + CPT_CONTENT_ARRAY, > > + CPT_CONTENT_DATA, > > + CPT_CONTENT_NAME, > > + CPT_CONTENT_REF, > > + CPT_CONTENT_MAX > > +}; > > + > > +#define CPT_SIGNATURE0 0x79 > > +#define CPT_SIGNATURE1 0x1c > > +#define CPT_SIGNATURE2 0x01 > > +#define CPT_SIGNATURE3 0x63 > > + > > +struct cpt_head > > +{ > > + __u8 cpt_signature[4]; /* Magic number */ > > + __u32 cpt_hdrlen; /* Header length */ > > + __u16 cpt_image_major; /* Format of this file */ > > + __u16 cpt_image_minor; /* Format of this file */ > > + __u16 cpt_image_sublevel; /* Format of this file */ > > + __u16 cpt_image_extra; /* Format of this file */ > > + __u16 cpt_arch; /* Architecture */ > > + __u16 cpt_pad1; > > + __u32 cpt_pad2; > > +#define CPT_ARCH_I386 0 > > + __u64 cpt_time; /* Time */ > > +} __attribute__ ((aligned (8))); > > + > > +/* Common object header. */ > > +struct cpt_object_hdr > > +{ > > + __u64 cpt_len; /* Size of current chunk of data */ > > + __u16 cpt_type; /* Type of object */ > > + __u32 cpt_hdrlen; /* Size of header */ > > + __u16 cpt_content; /* Content type: array, reference... */ > > +} __attribute__ ((aligned (8))); > > + > > +#endif /* __CPT_IMAGE_H_ */ > > diff --git a/cpt/sys.c b/cpt/sys.c > > index 4051286..8334c4c 100644 > > --- a/cpt/sys.c > > +++ b/cpt/sys.c > > @@ -13,21 +13,142 @@ > > #include <linux/sched.h> > > #include <linux/fs.h> > > #include <linux/file.h> > > -#include <linux/notifier.h> > > +#include <linux/uaccess.h> > > #include <linux/module.h> > > > > #include "cpt.h" > > +#include "cpt_image.h" > > > > MODULE_LICENSE("GPL"); > > > > +/* Debug level, constant for now */ > > +int debug_level = 1; > > + > > +static int file_write(const void *addr, size_t count, struct cpt_context > > *ctx) +{ > > + mm_segment_t oldfs; > > + ssize_t err = -EBADF; > > + struct file *file = ctx->file; > > + > > + oldfs = get_fs(); set_fs(KERNEL_DS); > > + if (file) > > + err = file->f_op->write(file, addr, count, &file->f_pos); > > + set_fs(oldfs); > > + if (err != count) > > + return err >= 0 ? -EIO : err; > > + return 0; > > +} > > + > > +static int file_read(void *addr, size_t count, struct cpt_context *ctx) > > +{ > > + mm_segment_t oldfs; > > + ssize_t err = -EBADF; > > + struct file *file = ctx->file; > > + > > + oldfs = get_fs(); set_fs(KERNEL_DS); > > + if (file) > > + err = file->f_op->read(file, addr, count, &file->f_pos); > > + set_fs(oldfs); > > + if (err != count) > > + return err >= 0 ? -EIO : err; > > + return 0; > > +} > > + > > +struct cpt_context * context_alloc(void) > > +{ > > + struct cpt_context *ctx; > > + int i; > > + > > + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); > > + if (!ctx) > > + return NULL; > > + > > + init_MUTEX(&ctx->main_sem); > > + ctx->refcount = 1; > > + > > + ctx->current_object = -1; > > + ctx->write = file_write; > > + ctx->read = file_read; > > + for (i = 0; i < CPT_OBJ_MAX; i++) { > > + INIT_LIST_HEAD(&ctx->object_array[i]); > > + } > > + > > + return ctx; > > +} > > + > > +void context_release(struct cpt_context *ctx) > > +{ > > + ctx->ctx_state = CPT_CTX_ERROR; > > + > > + if (ctx->file) > > + fput(ctx->file); > > + kfree(ctx); > > +} > > + > > +static void context_put(struct cpt_context *ctx) > > +{ > > + if (!--ctx->refcount) > > + context_release(ctx); > > +} > > + > > static int checkpoint(pid_t pid, int fd, unsigned long flags) > > { > > - return -ENOSYS; > > + struct file *file; > > + struct cpt_context *ctx; > > + int err; > > + > > + err = -EBADF; > > + file = fget(fd); > > + if (!file) > > + goto out; > > + > > + err = -ENOMEM; > > + ctx = context_alloc(); > > + if (!ctx) > > + goto out_file; > > + > > + ctx->file = file; > > + ctx->ctx_state = CPT_CTX_DUMPING; > > + > > + /* checkpoint */ > > + err = -ENOSYS; > > + > > + context_put(ctx); > > + > > +out_file: > > + fput(file); > > +out: > > + return err; > > } > > > > static int restart(int ctid, int fd, unsigned long flags) > > { > > - return -ENOSYS; > > + struct file *file; > > + struct cpt_context *ctx; > > + int err; > > + > > + err = -EBADF; > > + file = fget(fd); > > + if (!file) > > + goto out; > > + > > + err = -ENOMEM; > > + ctx = context_alloc(); > > + if (!ctx) > > + goto out_file; > > + > > + ctx->file = file; > > + ctx->ctx_state = CPT_CTX_UNDUMPING; > > + > > + /* restart */ > > + err = -ENOSYS; > > + > > + context_put(ctx); > > + > > +out_file: > > + fput(file); > > +out: > > + return err; > > } > > > > static int __init init_cptrst(void) -- 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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