From 313d64a35d36b4bb00edde418179ff1a5f342070 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 24 Jan 2021 23:49:04 -0500 Subject: do_splice_to(): move the logics for limiting the read length in Both callers have the identical logics limiting the amount of data we try to read into pipe - no more than would fit into that pipe. Move that into do_splice_to() itself. Signed-off-by: Al Viro --- fs/splice.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) (limited to 'fs/splice.c') diff --git a/fs/splice.c b/fs/splice.c index 866d5c2367b2..c1ca2cc63b43 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -771,11 +771,16 @@ static long do_splice_to(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { + unsigned int p_space; int ret; if (unlikely(!(in->f_mode & FMODE_READ))) return -EBADF; + /* Don't try to read more the pipe has space for. */ + p_space = pipe->max_usage - pipe_occupancy(pipe->head, pipe->tail); + len = min_t(size_t, len, p_space << PAGE_SHIFT); + ret = rw_verify_area(READ, in, ppos, len); if (unlikely(ret < 0)) return ret; @@ -856,15 +861,10 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, WARN_ON_ONCE(!pipe_empty(pipe->head, pipe->tail)); while (len) { - unsigned int p_space; size_t read_len; loff_t pos = sd->pos, prev_pos = pos; - /* Don't try to read more the pipe has space for. */ - p_space = pipe->max_usage - - pipe_occupancy(pipe->head, pipe->tail); - read_len = min_t(size_t, len, p_space << PAGE_SHIFT); - ret = do_splice_to(in, &pos, pipe, read_len, flags); + ret = do_splice_to(in, &pos, pipe, len, flags); if (unlikely(ret <= 0)) goto out_release; @@ -1083,15 +1083,8 @@ long do_splice(struct file *in, loff_t *off_in, struct file *out, pipe_lock(opipe); ret = wait_for_space(opipe, flags); - if (!ret) { - unsigned int p_space; - - /* Don't try to read more the pipe has space for. */ - p_space = opipe->max_usage - pipe_occupancy(opipe->head, opipe->tail); - len = min_t(size_t, len, p_space << PAGE_SHIFT); - + if (!ret) ret = do_splice_to(in, &offset, opipe, len, flags); - } pipe_unlock(opipe); if (ret > 0) wakeup_pipe_readers(opipe); -- cgit v1.2.3