Re: [PATCH] fuse: move page cache invalidation after AIO to workqueue

[Bernd Schubert]

On 3/3/26 13:03, Jingbo Xu wrote:
> 
> 
> On 3/3/26 6:23 PM, Bernd Schubert wrote:
>> From: Cheng Ding <cding@xxxxxxx>
>>
>> Invalidating the page cache in fuse_aio_complete() causes deadlock.
>> Call Trace:
>>  <TASK>
>>  __schedule+0x27c/0x6b0
>>  schedule+0x33/0x110
>>  io_schedule+0x46/0x80
>>  folio_wait_bit_common+0x136/0x330
>>  __folio_lock+0x17/0x30
>>  invalidate_inode_pages2_range+0x1d2/0x4f0
>>  fuse_aio_complete+0x258/0x270 [fuse]
>>  fuse_aio_complete_req+0x87/0xd0 [fuse]
>>  fuse_request_end+0x18e/0x200 [fuse]
>>  fuse_uring_req_end+0x87/0xd0 [fuse]
>>  fuse_uring_cmd+0x241/0xf20 [fuse]
>>  io_uring_cmd+0x9f/0x140
>>  io_issue_sqe+0x193/0x410
>>  io_submit_sqes+0x128/0x3e0
>>  __do_sys_io_uring_enter+0x2ea/0x490
>>  __x64_sys_io_uring_enter+0x22/0x40
>>
>> Move the invalidate_inode_pages2_range() call to a workqueue worker
>> to avoid this issue. This approach is similar to
>> iomap_dio_bio_end_io().
>>
>> (Minor edit by Bernd to avoid a merge conflict in Miklos' for-next
>> branch). The commit is based on that branch with the addition of
>> https://lore.kernel.org/r/20260111073701.6071-1-jefflexu@xxxxxxxxxxxxxxxxx)
> 
> I think it would be better to completely drop my previous patch and
> rework on the bare ground, as the patch
> (https://lore.kernel.org/r/20260111073701.6071-1-jefflexu@xxxxxxxxxxxxxxxxx)
> is only in Miklos's branch, not merged to the master yet.
> 
> 
> After reverting my previous patch, I think it would be cleaner by:
> 
> 
> "The page cache invalidation for FOPEN_DIRECT_IO write in
> fuse_direct_io() is moved to fuse_direct_write_iter() (with any progress
> in write), to keep consistent with generic_file_direct_write().  This
> covers the scenarios of both synchronous FOPEN_DIRECT_IO write
> (regardless FUSE_ASYNC_DIO) and asynchronous FOPEN_DIRECT_IO write
> without FUSE_ASYNC_DIO.
> 
> After that, only asynchronous direct write (for both FOPEN_DIRECT_IO and
> non-FOPEN_DIRECT_IO) with FUSE_ASYNC_DIO is left."

I think your suggestion moves into this direction

https://lore.kernel.org/all/20230918150313.3845114-1-bschubert@xxxxxxx/


Thanks,
Bernd