| Message ID | 55de39b6.amMqJlKPcMt+SaBx%akpm@linux-foundation.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 26, 2015 at 03:12:06PM -0700, Andrew Morton wrote: > From: yangwenfang <vicky.yangwenfang@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.yangwenfang@huawei.com> > Cc: Mark Fasheh <mfasheh@suse.com> > Cc: Joel Becker <jlbec@evilplan.org> > Cc: Zhangguanghui <zhang.guanghui@h3c.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mark Fasheh <mfasheh@suse.de> --Mark -- Mark Fasheh
diff -puN fs/ocfs2/aops.c~ocfs2-call-ocfs2_journal_access_di-before-ocfs2_journal_dirty-in-ocfs2_write_end_nolock fs/ocfs2/aops.c --- a/fs/ocfs2/aops.c~ocfs2-call-ocfs2_journal_access_di-before-ocfs2_journal_dirty-in-ocfs2_write_end_nolock +++ a/fs/ocfs2/aops.c @@ -2207,10 +2207,7 @@ try_again: if (ret) goto out_commit; } - /* - * We don't want this to fail in ocfs2_write_end(), so do it - * here. - */ + ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE); if (ret) { @@ -2367,7 +2364,7 @@ int ocfs2_write_end_nolock(struct addres loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { - int i; + int i, ret; unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1); struct inode *inode = mapping->host; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); @@ -2376,6 +2373,14 @@ int ocfs2_write_end_nolock(struct addres handle_t *handle = wc->w_handle; struct page *tmppage; + ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, + OCFS2_JOURNAL_ACCESS_WRITE); + if (ret) { + copied = ret; + mlog_errno(ret); + goto out; + } + if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { ocfs2_write_end_inline(inode, pos, len, &copied, di, wc); goto out_write_size; @@ -2431,6 +2436,7 @@ out_write_size: ocfs2_update_inode_fsync_trans(handle, inode, 1); ocfs2_journal_dirty(handle, wc->w_di_bh); +out: /* unlock pages before dealloc since it needs acquiring j_trans_barrier * lock, or it will cause a deadlock since journal commit threads holds * this lock and will ask for the page lock when flushing the data.