On Fri, Oct 04, 2024 at 03:33:56PM -0400, Gabriel Krisman Bertazi wrote: > > Regardless of what is right or wrong to do in ext4, I don't think that the test > > really cares about remount read-only. > > I don't see anything in the test that requires it. Gabriel? > > If I remove MS_RDONLY from the test it works just fine. > > If I recall correctly, no, there is no need for the MS_RDONLY. We only > care about getting the event to test FS_ERROR. Looking at ltp/testcases/kernel/syscalls/fanotify/fanotify22.c this appears to be true. I'll note though that this comment in fanotify22.c is a bit misleading: /* Unmount and mount the filesystem to get it out of the error state */ SAFE_UMOUNT(MOUNT_PATH); SAFE_MOUNT(tst_device->dev, MOUNT_PATH, tst_device->fs_type, 0, NULL); Once ext4_error() gets called, the file system will be marked as containing errors. This can be seen when you mount the file system, and when you run fsck -p: root@kvm-xfstests:~# mount /dev/vdc /vdc [ 1893.569015] EXT4-fs (vdc): mounted filesystem 9bf1a2df-fc1c-4b46-a8e8-c9e3e9bc7a26 r/w with ordered data mode. Quota mode: none. root@kvm-xfstests:~# echo "testing 123" > /sys/fs/ext4/vdc/trigger_fs_error [ 1907.268249] EXT4-fs error (device vdc): trigger_test_error:129: comm bash: testing 123 root@kvm-xfstests:~# umount /vdc [ 1919.722934] EXT4-fs (vdc): unmounting filesystem 9bf1a2df-fc1c-4b46-a8e8-c9e3e9bc7a26. root@kvm-xfstests:~# mount /dev/vdc /vdc [ 1923.270852] EXT4-fs (vdc): warning: mounting fs with errors, running e2fsck is recommended [ 1923.297998] EXT4-fs (vdc): mounted filesystem 9bf1a2df-fc1c-4b46-a8e8-c9e3e9bc7a26 r/w with ordered data mode. Quota mode: none. root@kvm-xfstests:~# umount /vdc [ 1925.889086] EXT4-fs (vdc): unmounting filesystem 9bf1a2df-fc1c-4b46-a8e8-c9e3e9bc7a26. root@kvm-xfstests:~# fsck -p /dev/vdc fsck from util-linux 2.38.1 /dev/vdc contains a file system with errors, check forced. /dev/vdc: 12/327680 files (0.0% non-contiguous), 42398/1310720 blocks Unmounting and remounting the file system is not going to clear file system's error state. You have to clear the EXT2_ERROR_FS state, and if you want to prevent fsck.ext4 -p from running, you'll need to set the EXT2_VALID_FS bit, via 'debugfs -w -R "ssv state 1" /dev/vdc' or you could just run 'fsck.ext4 -p /dev/vdc'. Also note that way I generally recommend that people simulate triggering a file system error is via a command like this: echo "test error description" > /sys/fs/ext4/vdc/trigger_fs_error To be honest, I had completely forgotten that the abort mount option exists at all, and if I didn't know that ltp was using it, I'd be inclined to deprecate and remove it.... - Ted
