From 18915b5873f07e5030e6fb108a050fa7c71c59fb Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Sat, 23 Mar 2019 12:10:29 -0400
Subject: [PATCH] ext4: prohibit fstrim in norecovery mode
Git-commit: 18915b5873f07e5030e6fb108a050fa7c71c59fb
Patch-mainline: v5.1-rc2
References: bsc#1207094
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@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
---
fs/ext4/ioctl.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index eb8ca8d80885..73435444b159 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1000,6 +1000,13 @@ 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;
--
2.35.3