Commit cd27e455 authored Oct 10, 2016 by Al Viro

[btrfs] fix check_direct_IO() for non-iovec iterators



looking for duplicate ->iov_base makes sense only for
iovec-backed iterators; for kvec-backed ones it's pointless,
for bvec-backed ones it's pointless and broken on 32bit (we
walk through an array of struct bio_vec accessing them as if
they were struct iovec; works by accident on 64bit, but on
32bit it'll blow up) and for pipe-backed ones it's pointless
and ends up oopsing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent b57332b4

fs/btrfs/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -8618,7 +8618,7 @@ static ssize_t check_direct_IO(struct btrfs_root root, struct kiocb iocb,
		goto out;

		/* If this is a write we don't need to check anymore */
		if (iov_iter_rw(iter) == WRITE)
		if (iov_iter_rw(iter) != READ \|\| !iter_is_iovec(iter))
		return 0;
		/*
		* Check to make sure we don't have duplicate iov_base's in this