On 8/28/23 13:59, Miklos Szeredi wrote:
On Thu, 24 Aug 2023 at 17:07, Bernd Schubert <bschubert@xxxxxxx> wrote:
fuse_direct_write_iter is basically duplicating what is already
in fuse_cache_write_iter/generic_file_direct_write. That can be
avoided by setting IOCB_DIRECT in fuse_file_write_iter, after that
fuse_cache_write_iter can be used for the FOPEN_DIRECT_IO code path
and fuse_direct_write_iter can be removed.
Cc: Hao Xu <howeyxu@xxxxxxxxxxx>
Cc: Miklos Szeredi <miklos@xxxxxxxxxx>
Cc: Dharmendra Singh <dsingh@xxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Bernd Schubert <bschubert@xxxxxxx>
---
fs/fuse/file.c | 54 ++++----------------------------------------------
1 file changed, 4 insertions(+), 50 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 905ce3bb0047..09277a54b711 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1589,52 +1589,6 @@ static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
return res;
}
-static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
- ssize_t res;
- bool exclusive_lock = fuse_dio_wr_exclusive_lock(iocb, from);
-
- /*
- * Take exclusive lock if
- * - Parallel direct writes are disabled - a user space decision
- * - Parallel direct writes are enabled and i_size is being extended.
- * This might not be needed at all, but needs further investigation.
- */
- if (exclusive_lock)
- inode_lock(inode);
- else {
- inode_lock_shared(inode);
-
- /* A race with truncate might have come up as the decision for
- * the lock type was done without holding the lock, check again.
- */
- if (fuse_direct_write_extending_i_size(iocb, from)) {
- inode_unlock_shared(inode);
- inode_lock(inode);
- exclusive_lock = true;
- }
- }
-
- res = generic_write_checks(iocb, from);
- if (res > 0) {
- 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".
Currently fuse_direct_IO() handles all cases (of which are many since
the requester can be sync or async and the server can be sync or
async).
Could this mess be cleaned up somehow?
I guess what you mean is to make the the replacement more obvious? I can
try... I need to think about how to do that. Before submitting the patch
I had looked up different code paths and I think fuse_direct_IO (called
by fuse_cache_write_iter -> generic_file_direct_write) all handles it.
Maybe a new patch like this in fuse_file_write_iter
if (condition1)
fuse_cache_write_iter
if (condition2)
fuse_cache_write_iter
...
and once all conditions in fuse_direct_write_iter are handled in
fuse_file_write_iter another the final patch (what is current this 4/5)
to remove fuse_direct_write_iter?
Also could we make the function names of fuse_direct_IO() and
fuse_direct_io() less similar, as this is a very annoying (though
minor) issue.
Entirely agreed, I had already thought about it, but wasn't sure why it
was named like this and didn't want to change too much.
Thanks,
Bernd
