linux-toradex.git/drivers/md/bitmap.c, branch v4.13-rc7

md/bitmap: don't read page from device with Bitmap_sync

2017-07-10T17:30:41+00:00

The device owns Bitmap_sync flag needs recovery
to become in sync, and read page from this type
device could get stale status.

Also add comments for Bitmap_sync bit per the
suggestion from Shaohua and Neil.

Previous disscussion can be found here:
https://marc.info/?t=149760428900004&r=1&w=2

Signed-off-by: Guoqing Jiang 
Signed-off-by: Shaohua Li

md: uuid debug statement now in processor byte order.

2017-05-24T22:58:43+00:00

Previously, the uuid debug statements were printed in little-endian
format, which wasn't consistent in machines that might not be in
little-endian byte order. With this change, the output will be
consistent for all machines with different byte-ordering.

Signed-off-by: Kyungchan Koh 
Signed-off-by: Shaohua Li

md: fix several trivial typos in comments

2017-03-24T05:54:57+00:00

Signed-off-by: Zhilong Liu 
Signed-off-by: Shaohua Li

md: move bitmap_destroy to the beginning of __md_stop

2017-03-16T23:55:58+00:00

Since we have switched to sync way to handle METADATA_UPDATED
msg for md-cluster, then process_metadata_update is depended
on mddev->thread->wqueue.

With the new change, clustered raid could possible hang if
array received a METADATA_UPDATED msg after array unregistered
mddev->thread, so we need to stop clustered raid (bitmap_destroy
-> bitmap_free -> md_cluster_stop) earlier than unregister
thread (mddev_detach -> md_unregister_thread).

And this change should be safe for non-clustered raid since
all writes are stopped before the destroy. Also in md_run,
we activate the personality (pers->run()) before activating
the bitmap (bitmap_create()). So it is pleasingly symmetric
to stop the bitmap (bitmap_destroy()) before stopping the
personality (__md_stop() calls pers->free()), we achieve this
by move bitmap_destroy to the beginning of __md_stop.

But we don't want to break the codes for waiting behind IO as
Shaohua mentioned, so introduce bitmap_wait_behind_writes to
call the codes, and call the new fun in both mddev_detach and
bitmap_destroy, then we will not break original behind IO code
and also fit the new condition well.

Signed-off-by: Guoqing Jiang 
Signed-off-by: Shaohua Li

md-cluster: introduce cluster_check_sync_size

2017-03-16T23:55:50+00:00

Support resize is a little complex for clustered
raid, since we need to ensure all the nodes share
the same knowledge about the size of raid.

We achieve the goal by check the sync_size which
is in each node's bitmap, we can only change the
capacity after cluster_check_sync_size returns 0.

Also, get_bitmap_from_slot is added to get a slot's
bitmap. And we exported some funcs since they are
used in cluster_check_sync_size().

We can also reuse get_bitmap_from_slot to remove
redundant code existed in bitmap_copy_from_slot.

Reviewed-by: NeilBrown 
Signed-off-by: Guoqing Jiang 
Signed-off-by: Shaohua Li

md: separate flags for superblock changes

2016-12-09T06:01:47+00:00

The mddev->flags are used for different purposes. There are a lot of
places we check/change the flags without masking unrelated flags, we
could check/change unrelated flags. These usage are most for superblock
write, so spearate superblock related flags. This should make the code
clearer and also fix real bugs.

Reviewed-by: NeilBrown 
Signed-off-by: Shaohua Li

md: Use REQ_FAILFAST_* on metadata writes where appropriate

2016-11-22T17:11:33+00:00

This can only be supported on personalities which ensure
that md_error() never causes an array to enter the 'failed'
state.  i.e. if marking a device Faulty would cause some
data to be inaccessible, the device is status is left as
non-Faulty.  This is true for RAID1 and RAID10.

If we get a failure writing metadata but the device doesn't
fail, it must be the last device so we re-write without
FAILFAST to improve chance of success.  We also flag the
device as LastDev so that future metadata updates don't
waste time on failfast writes.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

md/bitmap: add blktrace event for writes to the bitmap

2016-11-18T17:34:45+00:00

We trace wheneven bitmap_unplug() finds that it needs to write
to the bitmap, or when bitmap_daemon_work() find there is work
to do.

This makes it easier to correlate bitmap updates with data writes.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

md/bitmap: Don't write bitmap while earlier writes might be in-flight

2016-11-07T23:08:23+00:00

As we don't wait for writes to complete in bitmap_daemon_work, they
could still be in-flight when bitmap_unplug writes again.  Or when
bitmap_daemon_work tries to write again.
This can be confusing and could risk the wrong data being written last.

So make sure we wait for old writes to complete before new writes start.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

md/bitmap: change all printk() to pr_*()

2016-11-07T23:08:21+00:00

Follow err/warn distinction introduced in md.c
Join multi-part strings into single string.

Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li