From 0d9649341363047be60a9ec7378d8985bdd0abba Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 12 Jun 2022 16:07:49 -0400 Subject: splice: stop abusing iov_iter_advance() to flush a pipe Use pipe_discard_from() explicitly in generic_file_read_iter(); don't bother with rather non-obvious use of iov_iter_advance() in there. Reviewed-by: Jeff Layton Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Al Viro --- fs/splice.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/splice.c b/fs/splice.c index 93a2c9bf6249..877290500050 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -301,11 +301,9 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, { struct iov_iter to; struct kiocb kiocb; - unsigned int i_head; int ret; iov_iter_pipe(&to, READ, pipe, len); - i_head = to.head; init_sync_kiocb(&kiocb, in); kiocb.ki_pos = *ppos; ret = call_read_iter(in, &kiocb, &to); @@ -313,9 +311,8 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, *ppos = kiocb.ki_pos; file_accessed(in); } else if (ret < 0) { - to.head = i_head; - to.iov_offset = 0; - iov_iter_advance(&to, 0); /* to free what was emitted */ + /* free what was emitted */ + pipe_discard_from(pipe, to.start_head); /* * callers of ->splice_read() expect -EAGAIN on * "can't put anything in there", rather than -EFAULT. -- cgit v1.2.3