ext3: Replace lock/unlock_super() with an explicit lock for resizing

Use a separate lock to protect s_groups_count and the other block
group descriptors which get changed via an on-line resize operation,
so we can stop overloading the use of lock_super().

Port of ext4 commit 32ed5058ce90024efcd811254b4b1de0468099df by
Theodore Ts'o <tytso@mit.edu>.

CC: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/ext3_fs_sb.h b/include/linux/ext3_fs_sb.h
index dd61d83026a..258088ab3c6 100644
--- a/include/linux/ext3_fs_sb.h
+++ b/include/linux/ext3_fs_sb.h
@@ -73,6 +73,7 @@ struct ext3_sb_info {
         struct journal_s * s_journal;
         struct list_head s_orphan;
         struct mutex s_orphan_lock;
+        struct mutex s_resize_lock;
         unsigned long s_commit_interval;
         struct block_device *journal_bdev;
 #ifdef CONFIG_JBD_DEBUG