pipe: Fix iteration end check in fuse_dev_splice_write()

Fix the iteration end check in fuse_dev_splice_write().  The iterator
position can only be compared with == or != since wrappage may be involved.

Fixes: 8cefc107ca54 ("pipe: Use head and tail pointers for the ring, not cursor and length")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index d4e6691d2d92ccbd0e022c43478d4e46038aa985..8e02d76fe104aa4438f2076d7450d17683fc636f 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1965,7 +1965,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
 
        nbuf = 0;
        rem = 0;
-       for (idx = tail; idx < head && rem < len; idx++)
+       for (idx = tail; idx != head && rem < len; idx++)
                rem += pipe->bufs[idx & mask].len;
 
        ret = -EINVAL;