linux.git/drivers/block/drbd/drbd_worker.c, branch v3.14

block: Convert bio_for_each_segment() to bvec_iter

2013-11-24T06:33:49+00:00

More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.

This updates callers for the new usage without changing the
implementation yet.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Geert Uytterhoeven 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "Ed L. Cashin" 
Cc: Nick Piggin 
Cc: Lars Ellenberg 
Cc: Jiri Kosina 
Cc: Paul Clements 
Cc: Jim Paris 
Cc: Geoff Levand 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris 
Cc: Philip Kelleher 
Cc: Konrad Rzeszutek Wilk 
Cc: Jeremy Fitzhardinge 
Cc: Neil Brown 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama 
Cc: Sreekanth Reddy 
Cc: support@lsi.com
Cc: "James E.J. Bottomley" 
Cc: Greg Kroah-Hartman 
Cc: Alexander Viro 
Cc: Steven Whitehouse 
Cc: Herton Ronaldo Krzesinski 
Cc: Tejun Heo 
Cc: Andrew Morton 
Cc: Guo Chao 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Matthew Wilcox 
Cc: Keith Busch 
Cc: Stephen Hemminger 
Cc: Quoc-Son Anh 
Cc: Sebastian Ott 
Cc: Nitin Gupta 
Cc: Minchan Kim 
Cc: Jerome Marchand 
Cc: Seth Jennings 
Cc: "Martin K. Petersen" 
Cc: Mike Snitzer 
Cc: Vivek Goyal 
Cc: "Darrick J. Wong" 
Cc: Chris Metcalf 
Cc: Jan Kara 
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand

drbd: validate resync_after dependency on attach already

2013-03-28T16:10:25+00:00

We validated resync_after dependencies, if changed via disk-options.
But we did not validate them when first created via attach.
We also did not check or cleanup dependencies that used to be correct,
but now point to meanwhile removed minor devices.

If the drbd_resync_after_valid() validation in disk-options tried to
follow a dependency chain in this way, this could lead to NULL pointer
dereference.

Validate resync_after settings in drbd_adm_attach() already, as well as
in drbd_adm_disk_opts(), and and only reject dependency loops.
Depending on non-existing disks is allowed and equivalent to no dependency.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: abort start of resync early, if it raced with connection breakage

2013-03-28T16:10:24+00:00

We've seen a spurious full resync, because a connection breakage
raced with drbd_start_resync(, C_SYNC_TARGET),
and the resulting state change request intended to start the resync
ended up looking like a local invalidate.

Fix:
Double check the state inside the lock,
and don't even request that state change,
if we had connection or IO problems.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Clarify when activity log I/O is delegated to the worker thread

2013-03-23T00:14:00+00:00

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: read meta data early, base on-disk offsets on super block

2013-03-23T00:13:59+00:00

We used to calculate all on-disk meta data offsets, and then compare
the stored offsets, basically treating them as magic numbers.

Now with the activity log striping, the activity log size is no longer
fixed.  We need to first read the super block, then base the activity
log and bitmap offsets on the stored offsets/al stripe settings.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Broadcast sync progress no more often than once per second

2012-11-09T13:11:43+00:00

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg

drbd: always write bitmap on detach

2012-11-09T13:11:41+00:00

If we detach due to local read-error (which sets a bit in the bitmap),
stay Primary, and then re-attach (which re-reads the bitmap from disk),
we potentially lost the "out-of-sync" (or, "bad block") information in
the bitmap.

Always (try to) write out the changed bitmap pages before going diskless.

That way, we don't lose the bit for the bad block,
the next resync will fetch it from the peer, and rewrite
it locally, which may result in block reallocation in some
lower layer (or the hardware), and thereby "heal" the bad blocks.

If the bitmap writeout errors out as well, we will (again: try to)
mark the "we need a full sync" bit in our super block,
if it was a READ error; writes are covered by the activity log already.

If that superblock does not make it to disk either, we are sorry.

Maybe we just lost an entire disk or controller (or iSCSI connection),
and there actually are no bad blocks at all, so we don't need to
re-fetch from the peer, there is no "auto-healing" necessary.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg

drbd: a few more GFP_KERNEL -> GFP_NOIO

2012-11-09T13:11:40+00:00

This has not yet been observed, but conceivably, when using GFP_KERNEL
allocations from drbd_md_sync(), drbd_flush_after_epoch() or
receive_SyncParam(), we could trigger additional IO to our own device,
or an other device in a criss-cross setup, and end up in a local
deadlock, or potentially a distributed deadlock in a criss-cross setup
involving the peer blocked in a similar way waiting for us to make
progress.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg

drbd: use list_move_tail instead of list_del/list_add_tail

2012-11-09T13:11:39+00:00

Using list_move_tail() instead of list_del() + list_add_tail().

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun 
Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg

drbd: panic on delayed completion of aborted requests

2012-11-09T13:11:39+00:00

"aborting" requests, or force-detaching the disk, is intended for
completely blocked/hung local backing devices which do no longer
complete requests at all, not even do error completions.  In this
situation, usually a hard-reset and failover is the only way out.

By "aborting", basically faking a local error-completion,
we allow for a more graceful swichover by cleanly migrating services.
Still the affected node has to be rebooted "soon".

By completing these requests, we allow the upper layers to re-use
the associated data pages.

If later the local backing device "recovers", and now DMAs some data
from disk into the original request pages, in the best case it will
just put random data into unused pages; but typically it will corrupt
meanwhile completely unrelated data, causing all sorts of damage.

Which means delayed successful completion,
especially for READ requests,
is a reason to panic().

We assume that a delayed *error* completion is OK,
though we still will complain noisily about it.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg