Recently we found the performance of small direct writes is bad
when writeback_cache enabled. This is because we need to get
attrs from userspace in fuse_update_get_attr() on each write.
The timeout for the attributes doesn't work since every direct write
will invalidate the attrs in fuse_direct_IO().
To fix it, this patch tries to avoid invalidating attrs if writeback_cache
is enabled since we should trust local size/ctime/mtime in this case.
Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
fs/fuse/file.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 11404f8c21c7..5561d4cc735c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2868,8 +2868,11 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
}
if (iov_iter_rw(iter) == WRITE) {
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE);
- fuse_invalidate_attr(inode);
+ if (!fc->writeback_cache)
+ fuse_invalidate_attr(inode);
} else {
ret = __fuse_direct_read(io, iter, &pos);
}
--
2.11.0
