ext4: clear mmp sequence number when remounting read-only

[ Upstream commit 2dca60d98e241bea686004168f85208f215fc697 ]

Previously, when an MMP-protected file system is remounted read-only,
the kmmpd thread would exit the next time it woke up (a few seconds
later), without resetting the MMP sequence number back to
EXT4_MMP_SEQ_CLEAN.

Fix this by explicitly killing the MMP thread when the file system is
remounted read-only.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 27b9a76a0dfabeff3ee9ec65a15d8d5e711d851a..638ad47434771af1d2c2a90a17003271fe26e5a9 100644 (file)
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -186,11 +186,8 @@ static int kmmpd(void *data)
                        goto exit_thread;
                }
 
-               if (sb_rdonly(sb)) {
-                       ext4_warning(sb, "kmmpd being stopped since filesystem "
-                                    "has been remounted as readonly.");
-                       goto exit_thread;
-               }
+               if (sb_rdonly(sb))
+                       break;
 
                diff = jiffies - last_update_time;
                if (diff < mmp_update_interval * HZ)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f30d2bf40471eb489e537a33d4da09d0d0975bfc..b4fb085261fd93769c228e701000ac10410749d6 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5163,6 +5163,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 
                        if (sbi->s_journal)
                                ext4_mark_recovery_complete(sb, es);
+                       if (sbi->s_mmp_tsk)
+                               kthread_stop(sbi->s_mmp_tsk);
                } else {
                        /* Make sure we can mount this feature set readwrite */
                        if (ext4_has_feature_readonly(sb) ||