On Fri, Aug 16, 2019 at 6:41 AM Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx> wrote: > > Currently if md raid0/linear array gets one or more members removed while > being mounted, kernel keeps showing state 'clean' in the 'array_state' > sysfs attribute. Despite udev signaling the member device is gone, 'mdadm' > cannot issue the STOP_ARRAY ioctl successfully, given the array is mounted. > > Nothing else hints that something is wrong (except that the removed devices > don't show properly in the output of 'mdadm detail' command). There is no > other property to be checked, and if user is not performing reads/writes > to the array, even kernel log is quiet and doesn't give a clue about the > missing member. > > This patch changes this behavior; when 'array_state' is read we introduce > a non-expensive check (only for raid0/md-linear) that relies in the > comparison of the total number of disks when array was assembled with > gendisk flags of those devices to validate if all members are available > and functional. A new array state 'broken' was added: it mimics the state > 'clean' in every aspect, being useful only to distinguish if such array > has some member missing. Also, we show a rate-limited warning in kernel > log in such case. > > This patch has no proper functional change other than adding the > 'clean'-like state; it was tested with ext4 and xfs filesystems. It > requires a 'mdadm' counterpart to handle the 'broken' state. > > Cc: NeilBrown <neilb@xxxxxxxx> > Cc: Song Liu <songliubraving@xxxxxx> > Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx> If we merge this with the MD_BROKEN patch, would the code look simpler? Thanks, Song
