ACK/Cmnt: [SRU T/X/A/B][PATCH 1/1] fscache: Fix hanging wait on page discarded by writeback

[Daniel Axtens]

> I would classify a hang as high severity and therefore applicable to Artful
> still. Daniel, please update the importance of the bug tasks accordingly if you
> concur.

Done!

Regards,
Daniel

>
> Thanks,
> Stefan
>
>>  fs/fscache/page.c | 13 +++++++++----
>>  1 file changed, 9 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/fscache/page.c b/fs/fscache/page.c
>> index 961029e04027..da2fb58f2ecb 100644
>> --- a/fs/fscache/page.c
>> +++ b/fs/fscache/page.c
>> @@ -776,6 +776,7 @@ static void fscache_write_op(struct fscache_operation *_op)
>>
>>       _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
>>
>> +again:
>>       spin_lock(&object->lock);
>>       cookie = object->cookie;
>>
>> @@ -816,10 +817,6 @@ static void fscache_write_op(struct fscache_operation *_op)
>>               goto superseded;
>>       page = results[0];
>>       _debug("gang %d [%lx]", n, page->index);
>> -     if (page->index >= op->store_limit) {
>> -             fscache_stat(&fscache_n_store_pages_over_limit);
>> -             goto superseded;
>> -     }
>>
>>       radix_tree_tag_set(&cookie->stores, page->index,
>>                          FSCACHE_COOKIE_STORING_TAG);
>> @@ -829,6 +826,9 @@ static void fscache_write_op(struct fscache_operation *_op)
>>       spin_unlock(&cookie->stores_lock);
>>       spin_unlock(&object->lock);
>>
>> +     if (page->index >= op->store_limit)
>> +             goto discard_page;
>> +
>>       fscache_stat(&fscache_n_store_pages);
>>       fscache_stat(&fscache_n_cop_write_page);
>>       ret = object->cache->ops->write_page(op, page);
>> @@ -844,6 +844,11 @@ static void fscache_write_op(struct fscache_operation *_op)
>>       _leave("");
>>       return;
>>
>> +discard_page:
>> +     fscache_stat(&fscache_n_store_pages_over_limit);
>> +     fscache_end_page_write(object, page);
>> +     goto again;
>> +
>>  superseded:
>>       /* this writer is going away and there aren't any more things to
>>        * write */
>>
>
>