From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Wed, 9 Jan 2019 12:41:38 +0300
From: Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: Re: [tarantool-patches] [PATCH] Fix memory corruption while vinyl
 index rebuild
Message-ID: <20190109094138.kraktjvkh77gbi4e@esperanza>
References: <8feaa81ab383b2ef3fa4aa5bcf15864333388712.1546636533.git.georgy@tarantool.org>
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In-Reply-To: <8feaa81ab383b2ef3fa4aa5bcf15864333388712.1546636533.git.georgy@tarantool.org>
To: Georgy Kirichenko <georgy@tarantool.org>
Cc: tarantool-patches@freelists.org
List-ID: <tarantool-patches.dev.tarantool.org>

The issue's naturally worth fixing, but I don't think that it could
actually lead to a memory corruption, because the code doesn't yield.
AFAIU you stumbled upon it just by looking at the code, not that you
encountered a crash, right?

On Sat, Jan 05, 2019 at 12:18:01AM +0300, Georgy Kirichenko wrote:
> Reclaim memory used while previous page recovery not the last one.
> There is no specific test case.
> 
> Fixes: 3920

Closes #3920

Fixes commit a14d5e4e12ed2 ("vinyl: rebuild .index in force-recovery
mode").

> 
> Issue: https://github.com/tarantool/tarantool/issues/3920
> Branch: https://github.com/tarantool/tarantool/tree/g.kirichenko/gh-3920-rebuild-mem-corruption

Should go after --

'Issue' and 'Branch' prefixes are useless.

> diff --git a/src/box/vy_run.c b/src/box/vy_run.c
> index c448a449d..d82f1e372 100644
> --- a/src/box/vy_run.c
> +++ b/src/box/vy_run.c
> @@ -2382,6 +2382,7 @@ vy_run_rebuild_index(struct vy_run *run, const char *dir,
>  
>  	off_t page_offset, next_page_offset = xlog_cursor_pos(&cursor);
>  	while ((rc = xlog_cursor_next_tx(&cursor)) == 0) {
> +		region_truncate(region, mem_used);
>  		page_offset = next_page_offset;
>  		next_page_offset = xlog_cursor_pos(&cursor);
>  
> @@ -2441,7 +2442,6 @@ vy_run_rebuild_index(struct vy_run *run, const char *dir,
>  		info->row_index_offset = page_row_index_offset;
>  		++run->info.page_count;
>  		vy_run_acct_page(run, info);
> -		region_truncate(region, mem_used);
>  	}
>  
>  	if (prev_tuple != NULL) {

Pushed to 2.1 and 1.10.