Re: [PATCH 2/4] fs/block_dev: always invalidate cleancache in invalidate_bdev()
From: Nikolay Borisov
Date: Tue Apr 18 2017 - 14:52:25 EST
On 14.04.2017 17:07, Andrey Ryabinin wrote:
> invalidate_bdev() calls cleancache_invalidate_inode() iff ->nrpages != 0
> which doen't make any sense.
> Make invalidate_bdev() always invalidate cleancache data.
>
> Fixes: c515e1fd361c ("mm/fs: add hooks to support cleancache")
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> ---
> fs/block_dev.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index e405d8e..7af4787 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -103,12 +103,11 @@ void invalidate_bdev(struct block_device *bdev)
> {
> struct address_space *mapping = bdev->bd_inode->i_mapping;
>
> - if (mapping->nrpages == 0)
> - return;
> -
> - invalidate_bh_lrus();
> - lru_add_drain_all(); /* make sure all lru add caches are flushed */
> - invalidate_mapping_pages(mapping, 0, -1);
> + if (mapping->nrpages) {
> + invalidate_bh_lrus();
> + lru_add_drain_all(); /* make sure all lru add caches are flushed */
> + invalidate_mapping_pages(mapping, 0, -1);
> + }
How is this different than the current code? You will only invalidate
the mapping iff ->nrpages > 0 ( I assume it can't go down below 0) ?
Perhaps just remove the if altogether?
> /* 99% of the time, we don't need to flush the cleancache on the bdev.
> * But, for the strange corners, lets be cautious
> */
>