ext4: drop s_umount over opening the log device

[platform/kernel/linux-rpi.git] / fs / ext4 / super.c

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index fa8888f..47e3272 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5842,7 +5842,10 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
        if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
                return NULL;
 
+       /* see get_tree_bdev why this is needed and safe */
+       up_write(&sb->s_umount);
        bdev = ext4_blkdev_get(j_dev, sb);
+       down_write(&sb->s_umount);
        if (bdev == NULL)
                return NULL;