From: Ye Bin <yebin10@huawei.com> mainline inclusion from mainline-v5.13-rc1 commit ac2f7ca51b0929461ea49918f27c11b680f28995 category: bugfix bugzilla: 182973 CVE: NA ------------------------------------------------- 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: Zheng Liang <zhengliang6@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/ext4/super.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index a051671f7cb89..5a58f72ac2090 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -652,12 +652,6 @@ static void ext4_handle_error(struct super_block *sb, bool force_ro, int error, ext4_commit_super(sb); } - if (sb_rdonly(sb)) - return; - - if (continue_fs) - goto out; - /* * We force ERRORS_RO behavior when system is rebooting. Otherwise we * could panic during 'reboot -f' as the underlying device got already @@ -668,6 +662,12 @@ static void ext4_handle_error(struct super_block *sb, bool force_ro, int error, sb->s_id); } + if (sb_rdonly(sb)) + return; + + if (continue_fs) + goto out; + ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); /* * Make sure updated value of ->s_mount_flags will be visible before -- 2.25.1