On 8/29/23 15:26, Bernd Schubert wrote:
On 8/29/23 15:08, Bernd Schubert wrote:
On 8/28/23 17:05, Miklos Szeredi wrote:
On Mon, 28 Aug 2023 at 16:48, Bernd Schubert
<bernd.schubert@xxxxxxxxxxx> wrote:
On 8/28/23 13:59, Miklos Szeredi wrote:
On Thu, 24 Aug 2023 at 17:07, Bernd Schubert <bschubert@xxxxxxx>
wrote:
- if (!is_sync_kiocb(iocb) && iocb->ki_flags &
IOCB_DIRECT) {
- res = fuse_direct_IO(iocb, from);
- } else {
- res = fuse_direct_io(&io, from,
&iocb->ki_pos,
- FUSE_DIO_WRITE);
- fuse_write_update_attr(inode,
iocb->ki_pos, res);
While I think this is correct, I'd really like if the code to be
replaced and the replacement are at least somewhat comparable.
Sorry, I have a hard to time to understand "I'd really like if the code
to be replaced".
What I meant is that generic_file_direct_write() is not an obvious
replacement for the above lines of code.
The reason is that fuse_direct_IO() is handling the sync and async
cases in one function, while the above splits handling it based on
IOCB_DIRECT (which is now lost) and is_sync_kiocb(iocb). If it's okay
to lose IOCB_DIRECT then what's the explanation for the above
condition? It could be historic garbage, but we still need to
understand what is exactly happening.
While checking all code path again, I found an additional difference,
which I had missed before. FOPEN_DIRECT_IO will now act on
ff->fm->fc->async_dio when is is_sync_kiocb(iocb) is set.
Do you think that is a problem? If so, I could fix it in fuse_direct_IO.
What I mean is something like this
+ /* FOPEN_DIRECT_IO historically does not use async for blocking
O_DIRECT */
+ if (ff->open_flags & FOPEN_DIRECT_IO) {
+ if (!is_sync_kiocb(iocb) && ff->iocb_direct) {
+ /* no change */
+ } else {
+ io->async = 0;
+ }
+ }
Besides that it could use file->f_flags & O_DIRECT, I guess we can keep
async. It relates to commit
23c94e1cdcbf5953cd380555d0781caa42311870, which actually introduced
async for FOPEN_DIRECT_IO. I'm just going to add it to the commit message.
Thanks,
Bernd
