This is a combination that didn't really make sense before.
However when a reshape is converting e.g. raid5 -> raid6, the extra
device is not fully in-sync, but is certainly active and contains
important data.
So allow that start to be meaningful and in particular get
the 'recovery_offset' value (which is needed for any non-in-sync
active device) from the reshape_position.
Signed-off-by: NeilBrown <neilb@suse.de>
Each device has its own 'recovery_offset' showing how far
recovery has progressed on the device.
As the only real significance of this is that fact that it can
be stored in the metadata and recovered at restart, and as
only 1.x metadata can do this, we were only updating
'recovery_offset' to 'curr_resync_completed' when updating
v1.x metadata.
But this is wrong, and we will shortly make limited use of this
field in v0.90 metadata.
So move the update into common code.
Signed-off-by: NeilBrown <neilb@suse.de>
If a 'sync_max' has been set (via sysfs), it is wrong to clear it
until a resync (or reshape or recovery ...) actually reached that
point.
So if a resync is interrupted (e.g. by device failure),
leave 'resync_max' unchanged.
This is particularly important for 'reshape' operations that do not
change the size of the array. For such operations mdadm needs to
monitor the reshape taking rolling backups of the section being
reshaped. If resync_max gets cleared, the reshape can get ahead of
mdadm and then the backups that mdadm creates are useless.
This is suitable for 2.6.31.y stable kernels.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
When a raid5 (or raid6) array is being reshaped to have fewer devices,
conf->raid_disks is the latter and hence smaller number of devices.
However sometimes we want to use a number which is the total number of
currently required devices - the larger of the 'old' and 'new' sizes.
Before we implemented reducing the number of devices, this was always
'new' i.e. ->raid_disks.
Now we need max(raid_disks, previous_raid_disks) in those places.
This particularly affects assembling an array that was shutdown while
in the middle of a reshape to fewer devices.
md.c needs a similar fix when interpreting the md metadata.
Signed-off-by: NeilBrown <neilb@suse.de>
The management thread for raid4,5,6 arrays are all called
mdX_raid5, independent of the actual raid level, which is wrong and
can be confusion.
So change md_register_thread to use the name from the personality
unless no alternate name (like 'resync' or 'reshape') is given.
This is simpler and more correct.
Cc: Jinzc <zhenchengjin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Rename some variable and remove some duplicate definitions
to avoid there warnings. None of them are actual errors.
Signed-off-by: NeilBrown <neilb@suse.de>
Recent commit c8c00a6915
changed the exit paths in do_md_stop and was not quite
careful enough. There is one path were 'err' now needs
to be cleared but it isn't.
So setting an array to readonly (with mdadm --readonly) will
work, but will incorrectly report and error: ENXIO.
Signed-off-by: NeilBrown <neilb@suse.de>
Normally we only allow the upper limit for a reshape to be decreased
when the array not performing a sync/recovery/reshape, otherwise there
could be races. But if an array is part-way through a reshape when it
is assembled the reshape is started immediately leaving no window
to set an upper bound.
If the array is started read-only, the reshape will be suspended until
the array becomes writable, so that provides a window during which it
is perfectly safe to reduce the upper limit of a reshape.
So: allow the upper limit (sync_max) to be reduced even if the reshape
thread is running, as long as the array is still read-only.
Signed-off-by: NeilBrown <neilb@suse.de>
When assembling arrays, md allows two devices to have different event
counts as long as the difference is only '1'. This is to cope with
a system failure between updating the metadata on two difference
devices.
However there are currently times when we update the event count by
2. This was done to keep the event count even when the array is clean
and odd when it is dirty, which allows us to avoid writing common
update to spare devices and so allow those spares to go to sleep.
This is bad for the above reason. So change it to never increase by
two. This means that the alignment between 'odd/even' and
'clean/dirty' might take a little longer to attain, but that is only a
small cost. The spares will get a few more updates but that will
still be spared (;-) most updates and can still go to sleep.
Prior to this patch there was a small chance that after a crash an
array would fail to assemble due to the overly large event count
mismatch.
Signed-off-by: NeilBrown <neilb@suse.de>
A recent commit:
commit 449aad3e25
introduced the possibility of an A-B/B-A deadlock between
bd_mutex and reconfig_mutex.
__blkdev_get holds bd_mutex while calling md_open which takes
reconfig_mutex,
do_md_run is always called with reconfig_mutex held, and it now
takes bd_mutex in the call the revalidate_disk.
This potential deadlock was not caught by lockdep due to the
use of mutex_lock_interruptible_nexted which was introduced
by
commit d63a5a74de
do avoid a warning of an impossible deadlock.
It is quite possible to split reconfig_mutex in to two locks.
One protects the array data structures while it is being
reconfigured, the other ensures that an array is never even partially
open while it is being deactivated.
In particular, the second lock prevents an open from completing
between the time when do_md_stop checks if there are any active opens,
and the time when the array is either set read-only, or when ->pers is
set to NULL. So we can be certain that no IO is in flight as the
array is being destroyed.
So create a new lock, open_mutex, just to ensure exclusion between
'open' and 'stop'.
This avoids the deadlock and also avoids the lockdep warning mentioned
in commit d63a5a74d
Reported-by: "Mike Snitzer" <snitzer@gmail.com>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NeilBrown <neilb@suse.de>
As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode. So use that instead of mucking about with locks and
i_size_write.
Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.
Signed-off-by: NeilBrown <neilb@suse.de>
The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.
Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array. This isn't really safe.
So range-check the value first.
Signed-off-by: NeilBrown <neilb@suse.de>
When an array is changed from RAID6 to RAID5, fewer drives are
needed. So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.
md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity. The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().
The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.
For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics. printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.
<level> is now included in the output on each additional use.
Remove all uses of multiple KERN_<level>s in formats.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
User space can set various limits on an md array so that resync waits
when it gets to a certain point, or so that I/O is blocked for a short
while.
When md is waiting against one of these limit, it should use an
interruptible wait so as not to add to the load average, and so are
not to trigger a warning if the wait goes on for too long.
Signed-off-by: NeilBrown <neilb@suse.de>
As the recent bug in md_alloc showed, having a single exit path for
unlocking and putting is a good idea. So restructure md_alloc to have
a single mutex_unlock and mddev_put, and use gotos where necessary.
Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When an md device is created by name (rather than number) we need to
check that the name is not already in use. If this check finds a
duplicate, we return an error without dropping the lock or freeing
the newly create mddev.
This patch fixes that.
Cc: stable@kernel.org
Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If we try to modify one of the md/ sysfs files
suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
If the superblock of a component device indicates the presence of a
bitmap but the corresponding raid personality does not support bitmaps
(raid0, linear, multipath, faulty), then something is seriously wrong
and we'd better refuse to run such an array.
Currently, this check is performed while the superblocks are examined,
i.e. before entering personality code. Therefore the generic md layer
must know which raid levels support bitmaps and which do not.
This patch avoids this layer violation without adding identical code
to various personalities. This is accomplished by introducing a new
public function to md.c, md_check_no_bitmap(), which replaces the
hard-coded checks in the superblock loading functions.
A call to md_check_no_bitmap() is added to the ->run method of each
personality which does not support bitmaps and assembly is aborted
if at least one component device contains a bitmap.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
It is easiest to round sizes to multiples of chunk size in
the personality code for those personalities which care.
Those personalities now do the rounding, so we can
remove that function from common code.
Also remove the upper bound on the size of a chunk, and the lower
bound on the size of a device (1 chunk), neither of which really buy
us anything.
Signed-off-by: NeilBrown <neilb@suse.de>
Currently the assignment to utime gets skipped for 'external'
metadata. So move it to the top of the function so that it
always gets effected.
This is of largely cosmetic interest. Nothing actually depends
on ->utime being right for external arrays.
"mdadm --monitor" does use it for 0.90 and 1.x arrays, but with
mdadm-3.0, this is not important for external metadata.
Signed-off-by: NeilBrown <neilb@suse.de>
