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Theodore Ts'o authored
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@mit.edu> Reviewed-by:
Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org
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