Re: [PATCH 2/4] fs/block_dev: always invalidate cleancache in invalidate_bdev()
On 04/18/2017 09:51 PM, Nikolay Borisov wrote:
>
>
> 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
>> ---
>> 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) ?
The difference is that invalidate_bdev() now always calls
cleancache_invalidate_inode()
(you won't see it in this diff, it's placed after this if(mapping->nrpages){}
block,)
> Perhaps just remove the if altogether?
>
Given that invalidate_mapping_pages() invalidates exceptional entries as well,
it certainly doesn't look
right that we look only at mapping->nrpages and completely ignore
->nrexceptional.
So maybe removing if() would be a right thing to do. But I think that should be
a separate patch as it would
fix a another bug probably introduced by commit 91b0abe36a7b ("mm + fs: store
shadow entries in page cache")
My intention here was to fix only cleancache case.
>> /* 99% of the time, we don't need to flush the cleancache on the bdev.
>> * But, for the strange corners, lets be cautious
>> */
>>
Re: [PATCH 2/4] fs/block_dev: always invalidate cleancache in invalidate_bdev()
On 04/18/2017 09:51 PM, Nikolay Borisov wrote:
>
>
> 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
>> ---
>> 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) ?
The difference is that invalidate_bdev() now always calls
cleancache_invalidate_inode()
(you won't see it in this diff, it's placed after this if(mapping->nrpages){}
block,)
> Perhaps just remove the if altogether?
>
Given that invalidate_mapping_pages() invalidates exceptional entries as well,
it certainly doesn't look
right that we look only at mapping->nrpages and completely ignore
->nrexceptional.
So maybe removing if() would be a right thing to do. But I think that should be
a separate patch as it would
fix a another bug probably introduced by commit 91b0abe36a7b ("mm + fs: store
shadow entries in page cache")
My intention here was to fix only cleancache case.
>> /* 99% of the time, we don't need to flush the cleancache on the bdev.
>> * But, for the strange corners, lets be cautious
>> */
>>
Re: [PATCH 2/4] fs/block_dev: always invalidate cleancache in invalidate_bdev()
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
> ---
> 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
>*/
>
Re: [PATCH 2/4] fs/block_dev: always invalidate cleancache in invalidate_bdev()
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
> ---
> 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
>*/
>
