This is a note to let you know that I've just added the patch titled ext4: fix data=journal fast mount/umount hang to the 3.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-fix-data-journal-fast-mount-umount-hang.patch and it can be found in the queue-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2b405bfa84063bfa35621d2d6879f52693c614b0 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso@xxxxxxx> Date: Wed, 20 Mar 2013 09:42:11 -0400 Subject: ext4: fix data=journal fast mount/umount hang From: Theodore Ts'o <tytso@xxxxxxx> commit 2b405bfa84063bfa35621d2d6879f52693c614b0 upstream. In data=journal mode, if we unmount the file system before a transaction has a chance to complete, when the journal inode is being evicted, we can end up calling into jbd2_log_wait_commit() for the last transaction, after the journalling machinery has been shut down. Arguably we should adjust ext4_should_journal_data() to return FALSE for the journal inode, but the only place it matters is ext4_evict_inode(), and so to save a bit of CPU time, and to make the patch much more obviously correct by inspection(tm), we'll fix it by explicitly not trying to waiting for a journal commit when we are evicting the journal inode, since it's guaranteed to never succeed in this case. This can be easily replicated via: mount -t ext4 -o data=journal /dev/vdb /vdb ; umount /vdb ------------[ cut here ]------------ WARNING: at /usr/projects/linux/ext4/fs/jbd2/journal.c:542 __jbd2_log_start_commit+0xba/0xcd() Hardware name: Bochs JBD2: bad log_start_commit: 3005630206 3005630206 0 0 Modules linked in: Pid: 2909, comm: umount Not tainted 3.8.0-rc3 #1020 Call Trace: [<c015c0ef>] warn_slowpath_common+0x68/0x7d [<c02b7e7d>] ? __jbd2_log_start_commit+0xba/0xcd [<c015c177>] warn_slowpath_fmt+0x2b/0x2f [<c02b7e7d>] __jbd2_log_start_commit+0xba/0xcd [<c02b8075>] jbd2_log_start_commit+0x24/0x34 [<c0279ed5>] ext4_evict_inode+0x71/0x2e3 [<c021f0ec>] evict+0x94/0x135 [<c021f9aa>] iput+0x10a/0x110 [<c02b7836>] jbd2_journal_destroy+0x190/0x1ce [<c0175284>] ? bit_waitqueue+0x50/0x50 [<c028d23f>] ext4_put_super+0x52/0x294 [<c020efe3>] generic_shutdown_super+0x48/0xb4 [<c020f071>] kill_block_super+0x22/0x60 [<c020f3e0>] deactivate_locked_super+0x22/0x49 [<c020f5d6>] deactivate_super+0x30/0x33 [<c0222795>] mntput_no_expire+0x107/0x10c [<c02233a7>] sys_umount+0x2cf/0x2e0 [<c02233ca>] sys_oldumount+0x12/0x14 [<c08096b8>] syscall_call+0x7/0xb ---[ end trace 6a954cc790501c1f ]--- jbd2_log_wait_commit: error: j_commit_request=-1289337090, tid=0 Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -144,7 +144,8 @@ void ext4_evict_inode(struct inode *inod * don't use page cache. */ if (ext4_should_journal_data(inode) && - (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode))) { + (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) && + inode->i_ino != EXT4_JOURNAL_INO) { journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; tid_t commit_tid = EXT4_I(inode)->i_datasync_tid; Patches currently in stable-queue which might be from tytso@xxxxxxx are queue-3.4/ext4-fix-data-journal-fast-mount-umount-hang.patch queue-3.4/jbd2-fix-use-after-free-in-jbd2_journal_dirty_metadata.patch queue-3.4/ext4-fix-the-wrong-number-of-the-allocated-blocks-in-ext4_split_extent.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html