On July 17, 2023 10:03:11 AM GMT+02:00, Hao Xu <hao.xu@xxxxxxxxx> wrote:
>Hi Bernd,
>
>On 7/5/23 18:23, Bernd Schubert wrote:
>> From: Bernd Schubert <bschubert@xxxxxxx>
>>
>> In commit 153524053bbb0d27bb2e0be36d1b46862e9ce74c DIO
>> writes can be handled in parallel, as long as the file
>> is not extended. So far this only works when daemon/server
>> side set FOPEN_DIRECT_IO and FOPEN_PARALLEL_DIRECT_WRITES,
>> but O_DIRECT (iocb->ki_flags & IOCB_DIRECT) went another
>> code path that doesn't have the parallel DIO write
>> optimization.
>> Given that fuse_direct_write_iter has to handle page writes
>> and invalidation anyway (for mmap), the DIO handler in
>> fuse_cache_write_iter() is removed and DIO writes are now
>> only handled by fuse_direct_write_iter().
>>
>> Note: Correctness of this patch depends on a non-merged
>> series from Hao Xu <hao.xu@xxxxxxxxx>
>> ( fuse: add a new fuse init flag to relax restrictions in no cache mode)
>> ---
>> fs/fuse/file.c | 38 +++++---------------------------------
>> 1 file changed, 5 insertions(+), 33 deletions(-)
>>
>> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
>> index 89d97f6188e0..1490329b536c 100644
>> --- a/fs/fuse/file.c
>> +++ b/fs/fuse/file.c
>> @@ -1337,11 +1337,9 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
>> struct file *file = iocb->ki_filp;
>> struct address_space *mapping = file->f_mapping;
>> ssize_t written = 0;
>> - ssize_t written_buffered = 0;
>> struct inode *inode = mapping->host;
>> ssize_t err;
>> struct fuse_conn *fc = get_fuse_conn(inode);
>> - loff_t endbyte = 0;
>>
>> if (fc->writeback_cache) {
>> /* Update size (EOF optimization) and mode (SUID clearing) */
>> @@ -1377,37 +1375,10 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
>> if (err)
>> goto out;
>>
>> - if (iocb->ki_flags & IOCB_DIRECT) {
>> - loff_t pos = iocb->ki_pos;
>> - written = generic_file_direct_write(iocb, from);
>> - if (written < 0 || !iov_iter_count(from))
>> - goto out;
>> -
>> - pos += written;
>> -
>> - written_buffered = fuse_perform_write(iocb, mapping, from, pos);
>> - if (written_buffered < 0) {
>> - err = written_buffered;
>> - goto out;
>> - }
>> - endbyte = pos + written_buffered - 1;
>> -
>> - err = filemap_write_and_wait_range(file->f_mapping, pos,
>> - endbyte);
>> - if (err)
>> - goto out;
>> -
>> - invalidate_mapping_pages(file->f_mapping,
>> - pos >> PAGE_SHIFT,
>> - endbyte >> PAGE_SHIFT);
>> + written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
>> + if (written >= 0)
>> + iocb->ki_pos += written;
>>
>> - written += written_buffered;
>> - iocb->ki_pos = pos + written_buffered;
>> - } else {
>> - written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
>> - if (written >= 0)
>> - iocb->ki_pos += written;
>> - }
>> out:
>> current->backing_dev_info = NULL;
>> inode_unlock(inode);
>> @@ -1691,7 +1662,8 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>> if (FUSE_IS_DAX(inode))
>> return fuse_dax_write_iter(iocb, from);
>>
>> - if (!(ff->open_flags & FOPEN_DIRECT_IO))
>> + if (!(ff->open_flags & FOPEN_DIRECT_IO) &&
>> + !(iocb->ki_flags & IOCB_DIRECT))
>> return fuse_cache_write_iter(iocb, from);
>> else
>> return fuse_direct_write_iter(iocb, from);
>>
>
>For normal direct io(IOCB_DIRECT set, FOPEN_DIRECT_IO not set), it now
>goes to fuse_direct_write_iter() but the thing is the previous patchset
>I sent adds page flush and invalidation in FOPEN_DIRECT_IO
>and/or fc->direct_io_relax, so I guess this part(flush and invalidation)
>is not included in the normal direct io code path.
>
>Regards,
>Hao
>
Hi Hao,
I'm going to rebase to for-next and create a single patch set that should handle that, but only next week.
Thanks,
Bernd
