From: Ye Bin yebin10@huawei.com
commit ac2f7ca51b0929461ea49918f27c11b680f28995 upstream.
Before commit 014c9caa29d3 ("ext4: make ext4_abort() use __ext4_error()"), the following series of commands would trigger a panic:
1. mount /dev/sda -o ro,errors=panic test 2. mount /dev/sda -o remount,abort test
After commit 014c9caa29d3, remounting a file system using the test mount option "abort" will no longer trigger a panic. This commit will restore the behaviour immediately before commit 014c9caa29d3. (However, note that the Linux kernel's behavior has not been consistent; some previous kernel versions, including 5.4 and 4.19 similarly did not panic after using the mount option "abort".)
This also makes a change to long-standing behaviour; namely, the following series commands will now cause a panic, when previously it did not:
1. mount /dev/sda -o ro,errors=panic test 2. echo test > /sys/fs/ext4/sda/trigger_fs_error
However, this makes ext4's behaviour much more consistent, so this is a good thing.
Cc: stable@kernel.org Fixes: 014c9caa29d3 ("ext4: make ext4_abort() use __ext4_error()") Signed-off-by: Ye Bin yebin10@huawei.com Link: https://lore.kernel.org/r/20210401081903.3421208-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/super.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -667,9 +667,6 @@ static void ext4_handle_error(struct sup ext4_commit_super(sb); }
- if (sb_rdonly(sb) || continue_fs) - return; - /* * We force ERRORS_RO behavior when system is rebooting. Otherwise we * could panic during 'reboot -f' as the underlying device got already @@ -679,6 +676,10 @@ static void ext4_handle_error(struct sup panic("EXT4-fs (device %s): panic forced after error\n", sb->s_id); } + + if (sb_rdonly(sb) || continue_fs) + return; + ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); /* * Make sure updated value of ->s_mount_flags will be visible before