[CRIU] [PATCH 2/2] page-read: rewrite some code to use it in deduplication

[Pavel Emelyanov]

On 10/17/2013 05:07 PM, Tikhomirov Pavel wrote:
> 
> Signed-off-by: Tikhomirov Pavel <snorcht at gmail.com>
> ---
>  include/page-read.h |    2 ++
>  page-read.c         |   12 +++++++++---
>  2 files changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/include/page-read.h b/include/page-read.h
> index b19ea69..cbae2a0 100644
> --- a/include/page-read.h
> +++ b/include/page-read.h
> @@ -66,4 +66,6 @@ struct page_read {
>  };
>  
>  int open_page_read(int pid, struct page_read *);
> +inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov);
> +int seek_pagemap_page(struct page_read *pr, unsigned long vaddr);
>  #endif
> diff --git a/page-read.c b/page-read.c
> index a3ea7ac..6f3541c 100644
> --- a/page-read.c
> +++ b/page-read.c
> @@ -36,7 +36,7 @@ static int read_page(struct page_read *pr, unsigned long vaddr, void *buf)
>  	return 1;
>  }
>  
> -static inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov)
> +inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov)
>  {
>  	iov->iov_base = decode_pointer(pe->vaddr);
>  	iov->iov_len = pe->nr_pages * PAGE_SIZE;
> @@ -82,7 +82,7 @@ static void skip_pagemap_pages(struct page_read *pr, unsigned long len)
>  	pr->cvaddr += len;
>  }
>  
> -static int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
> +int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
>  {
>  	int ret;
>  	struct iovec iov;
> @@ -95,7 +95,11 @@ static int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
>  	while (1) {
>  		unsigned long iov_end;
>  
> -		BUG_ON(vaddr < pr->cvaddr);
> +		if (vaddr < pr->cvaddr) {
> +			pr_err("Missing %lu in parent pagemap, iov: base=%lu,len=%lu",
> +			       vaddr, (unsigned long)iov.iov_base, iov.iov_len);
> +			return -1;
> +		}
>  		iov_end = (unsigned long)iov.iov_base + iov.iov_len;
>  
>  		if (iov_end <= vaddr) {
> @@ -124,6 +128,8 @@ static int read_pagemap_page(struct page_read *pr, unsigned long vaddr, void *bu
>  		if (ret == -1)
>  			return ret;
>  		ret = read_pagemap_page(pr->parent, vaddr, buf);
> +		if (ret < 0)
> +			return ret;

This should be in separate patch. With comment.

>  	} else {
>  		pr_debug("\tpr%u Read page %lx from self %lx/%"PRIx64"\n", pr->id,
>  				vaddr, pr->cvaddr, lseek(pr->fd_pg, 0, SEEK_CUR));
>