From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx> [ Upstream commit 18915b5873f07e5030e6fb108a050fa7c71c59fb ] The ext4 fstrim implementation uses the block bitmaps to find free space that can be discarded. If we haven't replayed the journal, the bitmaps will be stale and we absolutely *cannot* use stale metadata to zap the underlying storage. Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/ext4/ioctl.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 7917cc89ab21..3dbf4e414706 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -940,6 +940,13 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (!blk_queue_discard(q)) return -EOPNOTSUPP; + /* + * We haven't replayed the journal, so we cannot use our + * block-bitmap-guided storage zapping commands. + */ + if (test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) + return -EROFS; + if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) return -EFAULT; -- 2.19.1
