New code for 5.5:

- Fix another place in the splice code where a pipe could ask a
 filesystem for a longer read than the pipe actually has free buffer
 space.
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Merge tag 'vfs-5.5-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull splice fix from Darrick Wong:
 "Fix another place in the splice code where a pipe could ask a
  filesystem for a longer read than the pipe actually has free buffer
  space"

* tag 'vfs-5.5-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  splice: only read in as much information as there is pipe buffer space
This commit is contained in:
Linus Torvalds 2019-11-30 10:48:24 -08:00
commit f112a2fd1f

View File

@ -945,12 +945,13 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
WARN_ON_ONCE(pipe->nrbufs != 0);
while (len) {
unsigned int pipe_pages;
size_t read_len;
loff_t pos = sd->pos, prev_pos = pos;
/* Don't try to read more the pipe has space for. */
read_len = min_t(size_t, len,
(pipe->buffers - pipe->nrbufs) << PAGE_SHIFT);
pipe_pages = pipe->buffers - pipe->nrbufs;
read_len = min(len, (size_t)pipe_pages << PAGE_SHIFT);
ret = do_splice_to(in, &pos, pipe, read_len, flags);
if (unlikely(ret <= 0))
goto out_release;
@ -1180,8 +1181,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
pipe_lock(opipe);
ret = wait_for_space(opipe, flags);
if (!ret)
if (!ret) {
unsigned int pipe_pages;
/* Don't try to read more the pipe has space for. */
pipe_pages = opipe->buffers - opipe->nrbufs;
len = min(len, (size_t)pipe_pages << PAGE_SHIFT);
ret = do_splice_to(in, &offset, opipe, len, flags);
}
pipe_unlock(opipe);
if (ret > 0)
wakeup_pipe_readers(opipe);