On Wed, Aug 26, 2015 at 03:12:06PM -0700, Andrew Morton wrote: > From: yangwenfang <vicky.yangwenf...@huawei.com> > Subject: ocfs2: call ocfs2_journal_access_di() before ocfs2_journal_dirty() > in ocfs2_write_end_nolock() > > 1: After we call ocfs2_journal_access_di() in ocfs2_write_begin(), > jbd2_journal_restart() may also be called, in this function transaction > A's t_updates-- and obtains a new transaction B. If > jbd2_journal_commit_transaction() is happened to commit transaction A, > when t_updates==0, it will continue to complete commit and unfile > buffer. > > So when jbd2_journal_dirty_metadata(), the handle is pointed a new > transaction B, and the buffer head's journal head is already freed, > jh->b_transaction == NULL, jh->b_next_transaction == NULL, it returns > EINVAL, So it triggers the BUG_ON(status). > > thread 1 jbd2 > ocfs2_write_begin jbd2_journal_commit_transaction > ocfs2_write_begin_nolock > ocfs2_start_trans > jbd2__journal_start(t_updates+1, > transaction A) > ocfs2_journal_access_di > ocfs2_write_cluster_by_desc > ocfs2_mark_extent_written > ocfs2_change_extent_flag > ocfs2_split_extent > ocfs2_extend_rotate_transaction > jbd2_journal_restart > (t_updates-1,transaction B) t_updates==0 > __jbd2_journal_refile_buffer > (jh->b_transaction = NULL) > ocfs2_write_end > ocfs2_write_end_nolock > ocfs2_journal_dirty > jbd2_journal_dirty_metadata(bug) > ocfs2_commit_trans > > 2. In ext4, I found that: jbd2_journal_get_write_access() called by > ext4_write_end. > > ext4_write_begin > ext4_journal_start > __ext4_journal_start_sb > ext4_journal_check_start > jbd2__journal_start > > ext4_write_end > ext4_mark_inode_dirty > ext4_reserve_inode_write > ext4_journal_get_write_access > jbd2_journal_get_write_access > ext4_mark_iloc_dirty > ext4_do_update_inode > ext4_handle_dirty_metadata > jbd2_journal_dirty_metadata > > 3. So I think we should put ocfs2_journal_access_di before > ocfs2_journal_dirty in the ocfs2_write_end. and it works well after my > modification. > > Signed-off-by: vicky <vicky.yangwenf...@huawei.com> > Cc: Mark Fasheh <mfas...@suse.com> > Cc: Joel Becker <jl...@evilplan.org> > Cc: Zhangguanghui <zhang.guang...@h3c.com> > Signed-off-by: Andrew Morton <a...@linux-foundation.org> Reviewed-by: Mark Fasheh <mfas...@suse.de> --Mark
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