backing-file: convert to using fops->splice_write

Filesystems may define their own splice write. Therefore, use the file
fops instead of invoking iter_file_splice_write() directly.

Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
Link: https://lore.kernel.org/r/20240708072208.25244-1-ed.tsai@mediatek.com
Fixes: 5ca73468612d ("fuse: implement splice read/write passthrough")
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/backing-file.c b/fs/backing-file.c
index afb557446c27c7fe8476b1b0d799ffc226d25ec2..8860dac58c37e147eebd27b58fa28c5fe4f2aa91 100644 (file)
--- a/fs/backing-file.c
+++ b/fs/backing-file.c
@@ -303,13 +303,16 @@ ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
        if (WARN_ON_ONCE(!(out->f_mode & FMODE_BACKING)))
                return -EIO;
 
+       if (!out->f_op->splice_write)
+               return -EINVAL;
+
        ret = file_remove_privs(ctx->user_file);
        if (ret)
                return ret;
 
        old_cred = override_creds(ctx->cred);
        file_start_write(out);
-       ret = iter_file_splice_write(pipe, out, ppos, len, flags);
+       ret = out->f_op->splice_write(pipe, out, ppos, len, flags);
        file_end_write(out);
        revert_creds(old_cred);