[CRIU] [PATCHv3 14/30] page-xfer: dump compatible iovec

Andrew Vagin avagin at virtuozzo.com
Tue Jul 5 01:25:20 PDT 2016


On Tue, Jun 28, 2016 at 10:24:07PM +0300, Dmitry Safonov wrote:
> Change page_xfer_dump_pages the way it could handle compatible iovs.
> Separated hole dumping in page_xfer_dump_hole and introduced
> iterator function get_iov which will return native iovec,
> converting compatible iovec if needed.
> 
> Fixes:
> (00.009060) Fetched ack: 7 7 0
> (00.009061) Transfering pages:
> (00.009062) 	buf 16/16
> (00.009063) 	p 0x100008048000 [32841]
> (00.009101) Error (page-xfer.c:504): Only 65536 of 17592320561152 bytes have been spliced
> (00.009253) page-pipe: Killing page pipe
> (00.009263) ----------------------------------------
> 

[root at fc22-vm criu]# ./test/zdtm.py run -t zdtm/static/env00  --pre 2
=== Run 1/1 ================

========================== Run zdtm/static/env00 in h ==========================
Start test
./env00 --pidfile=env00.pid --outfile=env00.out --envname=ENV_00_TEST
Run criu pre-dump
Run criu pre-dump
Run criu dump
Run criu restore
=[log]=> dump/zdtm/static/env00/24/3/restore.log
------------------------ grep Error ------------------------
(00.035223)     24: Error (mem.c:826): Page entry address 400000 outside of VMA 7fffddbcf000-7fffddbd1000
(00.035323) Error (cr-restore.c:1885): Restoring FAILED.
------------------------ ERROR OVER ------------------------
################# Test zdtm/static/env00 FAIL at CRIU restore ##################
##################################### FAIL #####################################

https://github.com/xemul/criu/issues/185

> Cc: Cyrill Gorcunov <gorcunov at openvz.org>
> Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
> ---
>  criu/include/page-pipe.h |  6 ++++
>  criu/page-pipe.c         |  6 ----
>  criu/page-xfer.c         | 88 +++++++++++++++++++++++++++++-------------------
>  3 files changed, 60 insertions(+), 40 deletions(-)
> 
> diff --git a/criu/include/page-pipe.h b/criu/include/page-pipe.h
> index 19e7a898e77f..474ffa004daa 100644
> --- a/criu/include/page-pipe.h
> +++ b/criu/include/page-pipe.h
> @@ -98,6 +98,12 @@ struct page_pipe {
>  	bool compat_iov;	/* Use compatible iovs (struct compat_iovec) */
>  };
>  
> +/* XXX: move to arch-depended file, when non-x86 add support for compat mode */
> +struct iovec_compat {
> +	u32	iov_base;
> +	u32	iov_len;
> +};
> +
>  extern struct page_pipe *create_page_pipe(unsigned int nr, struct iovec *,
>  					bool chunk_mode, bool compat_iov);
>  extern void destroy_page_pipe(struct page_pipe *p);
> diff --git a/criu/page-pipe.c b/criu/page-pipe.c
> index c38b96e89407..db597b27f1e2 100644
> --- a/criu/page-pipe.c
> +++ b/criu/page-pipe.c
> @@ -100,12 +100,6 @@ static struct page_pipe_buf *ppb_alloc_resize(struct page_pipe *pp, int size)
>  	return ppb;
>  }
>  
> -/* XXX: move to arch-depended file, when non-x86 add support for compat mode */
> -struct iovec_compat {
> -	u32	iov_base;
> -	u32	iov_len;
> -};
> -
>  static inline void iov_init_compat(struct iovec_compat *iov, unsigned long addr)
>  {
>  	iov->iov_base = (u32)addr;
> diff --git a/criu/page-xfer.c b/criu/page-xfer.c
> index 3813712fefcf..8c2c799c0b0f 100644
> --- a/criu/page-xfer.c
> +++ b/criu/page-xfer.c
> @@ -320,61 +320,81 @@ int open_page_xfer(struct page_xfer *xfer, int fd_type, long id)
>  		return open_page_local_xfer(xfer, fd_type, id);
>  }
>  
> +static int page_xfer_dump_hole(struct page_xfer *xfer,
> +		struct iovec *hole, unsigned long off)
> +{
> +	BUG_ON(hole->iov_base < (void *)off);
> +	hole->iov_base -= off;
> +	pr_debug("\th %p [%u]\n", hole->iov_base,
> +			(unsigned int)(hole->iov_len / PAGE_SIZE));
> +
> +	if (xfer->write_hole(xfer, hole))
> +		return -1;
> +
> +	return 0;
> +}
> +
> +static struct iovec get_iov(struct iovec *iovs, unsigned int n, bool compat)
> +{
> +	if (likely(!compat)) {
> +		return iovs[n];
> +	} else {
> +		struct iovec ret;
> +		struct iovec_compat *tmp = (struct iovec_compat*)(void *)iovs;
> +
> +		tmp += n;
> +		ret.iov_base = (void *)(uintptr_t)tmp->iov_base;
> +		ret.iov_len = tmp->iov_len;
> +		return ret;
> +	}
> +}
> +
>  int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
>  		unsigned long off)
>  {
>  	struct page_pipe_buf *ppb;
> -	struct iovec *hole = NULL;
> +	unsigned int cur_hole = 0;
> +	int ret;
>  
>  	pr_debug("Transfering pages:\n");
>  
> -	if (pp->free_hole)
> -		hole = &pp->holes[0];
> -
>  	list_for_each_entry(ppb, &pp->bufs, l) {
> -		int i;
> +		unsigned int i;
>  
>  		pr_debug("\tbuf %d/%d\n", ppb->pages_in, ppb->nr_segs);
>  
>  		for (i = 0; i < ppb->nr_segs; i++) {
> -			struct iovec *iov = &ppb->iov[i];
> -
> -			while (hole && (hole->iov_base < iov->iov_base)) {
> -				BUG_ON(hole->iov_base < (void *)off);
> -				hole->iov_base -= off;
> -				pr_debug("\th %p [%u]\n", hole->iov_base,
> -						(unsigned int)(hole->iov_len / PAGE_SIZE));
> -				if (xfer->write_hole(xfer, hole))
> -					return -1;
> -
> -				hole++;
> -				if (hole >= &pp->holes[pp->free_hole])
> -					hole = NULL;
> +			struct iovec iov = get_iov(ppb->iov, i, pp->compat_iov);
> +
> +			for (; cur_hole < pp->free_hole ; cur_hole++) {
> +				struct iovec hole = get_iov(pp->holes, cur_hole,
> +						pp->compat_iov);
> +
> +				if (hole.iov_base < iov.iov_base)
> +					break;
> +				ret = page_xfer_dump_hole(xfer, &hole, off);
> +				if (ret)
> +					return ret;
>  			}
>  
> -			BUG_ON(iov->iov_base < (void *)off);
> -			iov->iov_base -= off;
> -			pr_debug("\tp %p [%u]\n", iov->iov_base,
> -					(unsigned int)(iov->iov_len / PAGE_SIZE));
> +			BUG_ON(iov.iov_base < (void *)off);
> +			iov.iov_base -= off;
> +			pr_debug("\tp %p [%u]\n", iov.iov_base,
> +					(unsigned int)(iov.iov_len / PAGE_SIZE));
>  
> -			if (xfer->write_pagemap(xfer, iov))
> +			if (xfer->write_pagemap(xfer, &iov))
>  				return -1;
> -			if (xfer->write_pages(xfer, ppb->p[0], iov->iov_len))
> +			if (xfer->write_pages(xfer, ppb->p[0], iov.iov_len))
>  				return -1;
>  		}
>  	}
>  
> -	while (hole) {
> -		BUG_ON(hole->iov_base < (void *)off);
> -		hole->iov_base -= off;
> -		pr_debug("\th* %p [%u]\n", hole->iov_base,
> -				(unsigned int)(hole->iov_len / PAGE_SIZE));
> -		if (xfer->write_hole(xfer, hole))
> -			return -1;
> +	for (; cur_hole < pp->free_hole ; cur_hole++) {
> +		struct iovec hole = get_iov(pp->holes, cur_hole, pp->compat_iov);
>  
> -		hole++;
> -		if (hole >= &pp->holes[pp->free_hole])
> -			hole = NULL;
> +		ret = page_xfer_dump_hole(xfer, &hole, off);
> +		if (ret)
> +			return ret;
>  	}
>  
>  	return 0;
> -- 
> 2.9.0
> 
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