Re: [PATCH 0/8] netfs/cachefiles: Some bugfixes

[Gao Xiang <hsiangkao@linux.alibaba.com>]

Hi Zizhi,

On 2024/10/10 11:08, Zizhi Wo wrote:
> Hi!
> 
> This patchset involves some general cachefiles workflows and the on-
> demand loading process. For example, the eighth patch fixes a memory
> ordering issue in cachefiles, and the fifth patch includes some cleanup.
> These all related to changes in the general cachefiles workflow, and I
> think these deserve some attention.
> 
> Additionally, although the current EROFS on-demand loading mode based on
> cachefiles interaction might be considered for switching to the fanotify
> mode in the future, I believe the code based on the current cachefiles
> on-demand loading mode still requires maintenance. The first few patches
> here are bugfixes specifically for that.

Yes, I also agree with you.  I pinged David weeks ago, because many
bugfixes are not only impacted to cachefiles on-demand feature but
also generic cachefiles, hopefully they could be addressed upstream.

Thanks,
Gao Xiang

> 
> Therefore, I would greatly appreciate it if anyone could take some time
> to review these patches. So friendly ping.
> 
> Thanks,
> Zizhi Wo
> 
> 
> 在 2024/8/21 10:42, Zizhi Wo 写道:
>> Hi!
>>
>> We recently discovered some bugs through self-discovery and testing in
>> erofs ondemand loading mode, and this patchset is mainly used to fix
>> them. These patches are relatively simple changes, and I would be excited
>> to discuss them together with everyone. Below is a brief introduction to
>> each patch:
>>
>> Patch 1: Fix for wrong block_number calculated in ondemand write.
>>
>> Patch 2: Fix for wrong length return value in ondemand write.
>>
>> Patch 3: Fix missing position update in ondemand write, for scenarios
>> involving read-ahead, invoking the write syscall.
>>
>> Patch 4: Previously, the last redundant data was cleared during the umount
>> phase. This patch remove unnecessary data in advance.
>>
>> Patch 5: Code clean up for cachefiles_commit_tmpfile().
>>
>> Patch 6: Modify error return value in cachefiles_daemon_secctx().
>>
>> Patch 7: Fix object->file Null-pointer-dereference problem.
>>
>> Patch 8: Fix for memory out of order in fscache_create_volume().
>>
>>
>> Zizhi Wo (8):
>>    cachefiles: Fix incorrect block calculations in
>>      __cachefiles_prepare_write()
>>    cachefiles: Fix incorrect length return value in
>>      cachefiles_ondemand_fd_write_iter()
>>    cachefiles: Fix missing pos updates in
>>      cachefiles_ondemand_fd_write_iter()
>>    cachefiles: Clear invalid cache data in advance
>>    cachefiles: Clean up in cachefiles_commit_tmpfile()
>>    cachefiles: Modify inappropriate error return value in
>>      cachefiles_daemon_secctx()
>>    cachefiles: Fix NULL pointer dereference in object->file
>>    netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING
>>
>>   fs/cachefiles/daemon.c    |  2 +-
>>   fs/cachefiles/interface.c |  3 +++
>>   fs/cachefiles/io.c        | 10 +++++-----
>>   fs/cachefiles/namei.c     | 23 +++++++++++++----------
>>   fs/cachefiles/ondemand.c  | 38 +++++++++++++++++++++++++++++---------
>>   fs/netfs/fscache_volume.c |  3 +--
>>   6 files changed, 52 insertions(+), 27 deletions(-)
>>