linux-stable.git/drivers/md/raid1.c, branch v3.18.41

md/raid1: submit_bio_wait() returns 0 on success

2015-11-15T17:51:52+00:00

[ Upstream commit 203d27b0226a05202438ddb39ef0ef1acb14a759 ]

This was introduced with 9e882242c6193ae6f416f2d8d8db0d9126bd996b
which changed the return value of submit_bio_wait() to return != 0 on
error, but didn't update the caller accordingly.

Fixes: 9e882242c6 ("block: Add submit_bio_wait(), remove from md")
Cc: stable@vger.kernel.org (v3.10)
Reported-by: Bill Kuzeja 
Signed-off-by: Jes Sorensen 
Signed-off-by: NeilBrown 
Signed-off-by: Sasha Levin

md/raid1: fix test for 'was read error from last working device'.

2015-08-27T17:25:44+00:00

[ Upstream commit 34cab6f42003cb06f48f86a86652984dec338ae9 ]

When we get a read error from the last working device, we don't
try to repair it, and don't fail the device.  We simple report a
read error to the caller.

However the current test for 'is this the last working device' is
wrong.
When there is only one fully working device, it assumes that a
non-faulty device is that device.  However a spare which is rebuilding
would be non-faulty but so not the only working device.

So change the test from "!Faulty" to "In_sync".  If ->degraded says
there is only one fully working device and this device is in_sync,
this must be the one.

This bug has existed since we allowed read_balance to read from
a recovering spare in v3.0

Reported-and-tested-by: Alexander Lyakas 
Fixes: 76073054c95b ("md/raid1: clean up read_balance.")
Cc: stable@vger.kernel.org (v3.0+)
Signed-off-by: NeilBrown 
Signed-off-by: Sasha Levin

md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies

2015-08-27T17:25:33+00:00

[ Upstream commit 423f04d63cf421ea436bcc5be02543d549ce4b28 ]

raid1_end_read_request() assumes that the In_sync bits are consistent
with the ->degaded count.
raid1_spare_active updates the In_sync bit before the ->degraded count
and so exposes an inconsistency, as does error()
So extend the spinlock in raid1_spare_active() and error() to hide those
inconsistencies.

This should probably be part of
  Commit: 34cab6f42003 ("md/raid1: fix test for 'was read error from
  last working device'.")
as it addresses the same issue.  It fixes the same bug and should go
to -stable for same reasons.

Fixes: 76073054c95b ("md/raid1: clean up read_balance.")
Cc: stable@vger.kernel.org (v3.0+)
Signed-off-by: NeilBrown 
Signed-off-by: Sasha Levin

md/raid1: fix read balance when a drive is write-mostly.

2015-03-06T22:53:05+00:00

commit d1901ef099c38afd11add4cfb3312c02ef21ec4a upstream.

When a drive is marked write-mostly it should only be the
target of reads if there is no other option.

This behaviour was broken by

commit 9dedf60313fa4dddfd5b9b226a0ef12a512bf9dc
    md/raid1: read balance chooses idlest disk for SSD

which causes a write-mostly device to be *preferred* is some cases.

Restore correct behaviour by checking and setting
best_dist_disk and best_pending_disk rather than best_disk.

We only need to test one of these as they are both changed
from -1 or >=0 at the same time.

As we leave min_pending and best_dist unchanged, any non-write-mostly
device will appear better than the write-mostly device.

Reported-by: Tomáš Hodek 
Reported-by: Dark Penguin 
Signed-off-by: NeilBrown 
Link: http://marc.info/?l=linux-raid&m=135982797322422
Fixes: 9dedf60313fa4dddfd5b9b226a0ef12a512bf9dc
Signed-off-by: Greg Kroah-Hartman

md: remove unwanted white space from md.c

2014-10-14T02:08:29+00:00

My editor shows much of this is RED.

Signed-off-by: NeilBrown

md/raid1: process_checks doesn't use its return value.

2014-10-14T02:08:28+00:00

process_checks() always returns '0', so change it to 'void'.

Signed-off-by: NeilBrown

md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.

2014-10-08T23:07:04+00:00

Using {set,clear}_bit is more consistent than shifting and masking.

No functional change.

Signed-off-by: NeilBrown

md/raid1: minor typos and reformatting.

2014-10-08T23:07:04+00:00

Signed-off-by: NeilBrown

md/raid1: fix_read_error should act on all non-faulty devices.

2014-09-22T01:26:01+00:00

If a devices is being recovered it is not InSync and is not Faulty.

If a read error is experienced on that device, fix_read_error()
will be called, but it ignores non-InSync devices.  So it will
neither fix the error nor fail the device.

It is incorrect that fix_read_error() ignores non-InSync devices.
It should only ignore Faulty devices.  So fix it.

This became a bug when we allowed reading from a device that was being
recovered.  It is suitable for any subsequent -stable kernel.

Fixes: da8840a747c0dbf49506ec906757a6b87b9741e9
Cc: stable@vger.kernel.org (v3.5+)
Reported-by: Alexander Lyakas 
Tested-by: Alexander Lyakas 
Signed-off-by: NeilBrown

md/raid1: count resync requests in nr_pending.

2014-09-22T01:26:01+00:00

Both normal IO and resync IO can be retried with reschedule_retry()
and so be counted into ->nr_queued, but only normal IO gets counted in
->nr_pending.

Before the recent improvement to RAID1 resync there could only
possibly have been one or the other on the queue.  When handling a
read failure it could only be normal IO.  So when handle_read_error()
called freeze_array() the fact that freeze_array only compares
->nr_queued against ->nr_pending was safe.

But now that these two types can interleave, we can have both normal
and resync IO requests queued, so we need to count them both in
nr_pending.

This error can lead to freeze_array() hanging if there is a read
error, so it is suitable for -stable.

Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761
cc: stable@vger.kernel.org (v3.13+)
Reported-by: Brassow Jonathan 
Signed-off-by: NeilBrown