From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sonic Zhang Date: Thu Mar 18 21:15:39 2004 Subject: [Ocfs2-devel] mark_buffer_dirty() reports buffer_head is not uptodate in JBDroutine journal_create() in kernel 2.6. Message-ID: <405A65E8.3010904@intel.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com Hi Stephen, I found a bug in JBD routine journal_create() in kernel 2.6, when I debug the OCFS v2 driver. mark_buffer_dirty() reports buffer_head is not uptodate. See following bug description. ------------------------------------------------------- OS: Linux Kernel 2.6.1 Plarform: IA32 Steps: 1. Build the ocfs v2 driver under kernel 2.6. 2. insert ocfs2.ko into kernel 2.6. 3. mkfs.ocfs2 -F -b 4 -l testocfs -m /mnt/ocfs2 /dev/hdb2 4. mount -t ocfs2 /dev/hdb2 /mnt/ocfs2 Results: buffer layer error at fs/buffer.c:1266 Call Trace: [<>] mark_buffer_dirty [<>] journal_create [<>] ocfs_journal_create [<>] ocfs_check_volume [<>] ocfs_mount_volume ...... ------------------------------------------------------- I think I found the root cause of the bug reported in mark_buffer_dirty(). It is caused in the Linux journaling routine(JBD) journal_create(). In kernel 2.6.x, buffer_head state BH_Uptodate is checked in mark_buffer_dirty(), while kernel 2.4.x doesn't do. If this state doesn't exist in the buffer_head, buffer error information is reported. But, in routine journal_create(), the state BH_Uptodate is set after the call to mark_buffer_dirty(). This works well in kernel 2.4.x, but fails in kernel 2.6.x. I attach a patch to fix this bug in kernel 2.6.x. Please check if it works well in kernel 2.6.x. ------------------------------------------------------- --- linux-2.6.4a/fs/jbd/journal.c 2004-03-19 10:40:49.264613984 +0800 +++ linux-2.6.4/fs/jbd/journal.c 2004-03-19 10:41:12.091143824 +0800 @@ -832,10 +832,10 @@ bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); lock_buffer(bh); memset (bh->b_data, 0, journal->j_blocksize); - BUFFER_TRACE(bh, "marking dirty"); - mark_buffer_dirty(bh); BUFFER_TRACE(bh, "marking uptodate"); set_buffer_uptodate(bh); + BUFFER_TRACE(bh, "marking dirty"); + mark_buffer_dirty(bh); unlock_buffer(bh); __brelse(bh); } --Sonic Zhang