[Devel] [PATCH rh7 1/2] mm/tcache: Reset index before repeating invalidation

[Kirill Tkhai]

On 28.02.2018 18:01, Andrey Ryabinin wrote:
> Commit 25176cdcdcc0 ("tcache: Fix race between tcache_invalidate_node()
> 	and tcache_attach_page()")
> removed reseting index before repeating invalidation. Essentially this
> broke repeat logic entirely as we retry invalidation past the end of
> the file.
> 
> Reset index to zero before invalidation retry.
> 
> https://jira.sw.ru/browse/PSBM-81760
> Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>

Acked-by: Kirill Tkhai <ktkhai at virtuozzo.com>

> ---
>  mm/tcache.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/tcache.c b/mm/tcache.c
> index 6e0c10dd3339..31a9eb3d1e12 100644
> --- a/mm/tcache.c
> +++ b/mm/tcache.c
> @@ -918,7 +918,7 @@ tcache_invalidate_node_pages(struct tcache_node *node)
>  	bool repeat, synchronize_sched_once = true;
>  	pgoff_t indices[TCACHE_PAGEVEC_SIZE];
>  	struct page *pages[TCACHE_PAGEVEC_SIZE];
> -	pgoff_t index = 0;
> +	pgoff_t index;
>  	unsigned nr_pages;
>  	int i;
>  
> @@ -926,6 +926,7 @@ tcache_invalidate_node_pages(struct tcache_node *node)
>  	 * First forbid new page insertions - see tcache_page_tree_replace.
>  	 */
>  again:
> +	index = 0;
>  	repeat = false;
>  	while ((nr_pages = tcache_lookup(pages, node, index,
>  						TCACHE_PAGEVEC_SIZE, indices))) {
>