On Mon, Mar 14, 2016 at 11:34:59AM +0900, Daeho Jeong wrote: > Now, in ext4, there is a race condition between changing inode journal > mode and ext4_writepages(). While ext4_writepages() is executed on > a non-journalled mode inode, the inode's journal mode could be enabled > by ioctl() and then, some pages dirtied after switching the journal > mode will be still exposed to ext4_writepages() in non-journaled mode. > To resolve this problem, we use fs-wide per-cpu rw semaphore by > Jan Kara's suggestion because we don't want to waste ext4_inode_info's > space for this extra rare case. > > Signed-off-by: Daeho Jeong <daeho.jeong@xxxxxxxxxxx> > Signed-off-by: Jan Kara <jack@xxxxxxx> Hi Daeho, This patch is causing a regression for xfstests generic/231 when using a 1k block size (this case tests what happens when the blocksize < page size, such as if you are using a 4k blocksize on a Power PC system). If you have kvm-xfstests or gce-xfstests[1] installed you can reproduce it like this: gce-xfstests -c 1k -C 10 generic/231 (Or use kvm-xfstests if you don't want to get a GCE account). [1] http://thunk.org/gce-xfstests You will get this: BEGIN TEST 1k: Ext4 1k block Wed Apr 27 00:48:01 EDT 2016 DEVICE: /dev/mapper/xt-vdd MK2FS OPTIONS: -q -b 1024 MOUNT OPTIONS: -o block_validity FSTYP -- ext4 PLATFORM -- Linux/x86_64 xfstests-201604270046 4.6.0-rc4-ext4-00010-geed525e MKFS_OPTIONS -- -q -b 1024 /dev/mapper/xt-vdc MOUNT_OPTIONS -- -o acl,user_xattr -o block_validity /dev/mapper/xt-vdc /xt-vdc generic/231 64s ... [00:48:03] [00:49:44] [failed, exit status 1] - output mismatch (see /results/results-1k/generic/231.out.bad) --- tests/generic/231.out 2016-04-27 00:15:36.000000000 -0400 +++ /results/results-1k/generic/231.out.bad 2016-04-27 00:49:44.701895666 -0400 @@ -4,13 +4,10041 @@ Comparing user usage Comparing group usage === FSX Standard Mode, Memory Mapping, 4 Tasks === -All 20000 operations completed A-OK! -All 20000 operations completed A-OK! -All 20000 operations completed A-OK! -All 20000 operations completed A-OK! ... (Run 'diff -u tests/generic/231.out /results/results-1k/generic/231.out.bad' to see the entire diff) Ran: generic/231 Failures: generic/231 Failed 1 of 1 tests I'm going to drop patch 2 and 3 of your patch series from the ext4 tree for now. Could you take a closer look? Thanks, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
