1 files changed, 28 insertions, 31 deletions

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 68fbeedd627b..bc364c119af6 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -127,9 +127,9 @@ void __dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
  */
 static int kmmpd(void *data)
 {
-	struct super_block *sb = ((struct mmpd_data *) data)->sb;
-	struct buffer_head *bh = ((struct mmpd_data *) data)->bh;
+	struct super_block *sb = (struct super_block *) data;
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+	struct buffer_head *bh = EXT4_SB(sb)->s_mmp_bh;
 	struct mmp_struct *mmp;
 	ext4_fsblk_t mmp_block;
 	u32 seq = 0;
@@ -156,7 +156,12 @@ static int kmmpd(void *data)
 	memcpy(mmp->mmp_nodename, init_utsname()->nodename,
 	       sizeof(mmp->mmp_nodename));
 
-	while (!kthread_should_stop()) {
+	while (!kthread_should_stop() && !sb_rdonly(sb)) {
+		if (!ext4_has_feature_mmp(sb)) {
+			ext4_warning(sb, "kmmpd being stopped since MMP feature"
+				     " has been disabled.");
+			goto wait_to_exit;
+		}
 		if (++seq > EXT4_MMP_SEQ_MAX)
 			seq = 1;
 
@@ -177,16 +182,6 @@ static int kmmpd(void *data)
 			failed_writes++;
 		}
 
-		if (!(le32_to_cpu(es->s_feature_incompat) &
-		    EXT4_FEATURE_INCOMPAT_MMP)) {
-			ext4_warning(sb, "kmmpd being stopped since MMP feature"
-				     " has been disabled.");
-			goto exit_thread;
-		}
-
-		if (sb_rdonly(sb))
-			break;
-
 		diff = jiffies - last_update_time;
 		if (diff < mmp_update_interval * HZ)
 			schedule_timeout_interruptible(mmp_update_interval *
@@ -207,7 +202,7 @@ static int kmmpd(void *data)
 				ext4_error_err(sb, -retval,
 					       "error reading MMP data: %d",
 					       retval);
-				goto exit_thread;
+				goto wait_to_exit;
 			}
 
 			mmp_check = (struct mmp_struct *)(bh_check->b_data);
@@ -221,7 +216,7 @@ static int kmmpd(void *data)
 				ext4_error_err(sb, EBUSY, "abort");
 				put_bh(bh_check);
 				retval = -EBUSY;
-				goto exit_thread;
+				goto wait_to_exit;
 			}
 			put_bh(bh_check);
 		}
@@ -244,13 +239,25 @@ static int kmmpd(void *data)
 
 	retval = write_mmp_block(sb, bh);
 
-exit_thread:
-	EXT4_SB(sb)->s_mmp_tsk = NULL;
-	kfree(data);
-	brelse(bh);
+wait_to_exit:
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!kthread_should_stop())
+			schedule();
+	}
+	set_current_state(TASK_RUNNING);
 	return retval;
 }
 
+void ext4_stop_mmpd(struct ext4_sb_info *sbi)
+{
+	if (sbi->s_mmp_tsk) {
+		kthread_stop(sbi->s_mmp_tsk);
+		brelse(sbi->s_mmp_bh);
+		sbi->s_mmp_tsk = NULL;
+	}
+}
+
 /*
  * Get a random new sequence number but make sure it is not greater than
  * EXT4_MMP_SEQ_MAX.
@@ -275,7 +282,6 @@ int ext4_multi_mount_protect(struct super_block *sb,
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 	struct buffer_head *bh = NULL;
 	struct mmp_struct *mmp = NULL;
-	struct mmpd_data *mmpd_data;
 	u32 seq;
 	unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);
 	unsigned int wait_time = 0;
@@ -364,24 +370,17 @@ skip:
 		goto failed;
 	}
 
-	mmpd_data = kmalloc(sizeof(*mmpd_data), GFP_KERNEL);
-	if (!mmpd_data) {
-		ext4_warning(sb, "not enough memory for mmpd_data");
-		goto failed;
-	}
-	mmpd_data->sb = sb;
-	mmpd_data->bh = bh;
+	EXT4_SB(sb)->s_mmp_bh = bh;
 
 	/*
 	 * Start a kernel thread to update the MMP block periodically.
 	 */
-	EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, mmpd_data, "kmmpd-%.*s",
+	EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%.*s",
 					     (int)sizeof(mmp->mmp_bdevname),
 					     bdevname(bh->b_bdev,
 						      mmp->mmp_bdevname));
 	if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) {
 		EXT4_SB(sb)->s_mmp_tsk = NULL;
-		kfree(mmpd_data);
 		ext4_warning(sb, "Unable to create kmmpd thread for %s.",
 			     sb->s_id);
 		goto failed;
@@ -393,5 +392,3 @@ failed:
 	brelse(bh);
 	return 1;
 }
-
-