linux-stable.git/drivers/md, branch v4.1.6

dm: fix dm_merge_bvec regression on 32 bit systems

2015-08-17T03:52:23+00:00

commit bd4aaf8f9b85d6b2df3231fd62b219ebb75d3568 upstream.

A DM regression on 32 bit systems was reported against v4.2-rc3 here:
https://lkml.org/lkml/2015/7/29/401

Fix this by reverting both commit 1c220c69 ("dm: fix casting bug in
dm_merge_bvec()") and 148e51ba ("dm: improve documentation and code
clarity in dm_merge_bvec").  This combined revert is done to eliminate
the possibility of a partial revert in stable@ kernels.

In hindsight the correct fix, at the time 1c220c69 was applied to fix
the regression that 148e51ba introduced, should've been to simply revert
148e51ba.

Reported-by: Josh Boyer 
Tested-by: Adam Williamson 
Acked-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies

2015-08-17T03:52:23+00:00

commit 423f04d63cf421ea436bcc5be02543d549ce4b28 upstream.

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.")
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: use kzalloc() when bitmap is disabled

2015-08-17T03:52:13+00:00

commit b6878d9e03043695dbf3fa1caa6dfc09db225b16 upstream.

In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
mdu_bitmap_file_t called "file".

5769         file = kmalloc(sizeof(*file), GFP_NOIO);
5770         if (!file)
5771                 return -ENOMEM;

This structure is copied to user space at the end of the function.

5786         if (err == 0 &&
5787             copy_to_user(arg, file, sizeof(*file)))
5788                 err = -EFAULT

But if bitmap is disabled only the first byte of "file" is initialized
with zero, so it's possible to read some bytes (up to 4095) of kernel
space memory from user space. This is an information leak.

5775         /* bitmap disabled, zero the first byte and copy out */
5776         if (!mddev->bitmap_info.file)
5777                 file->pathname[0] = '\0';

Signed-off-by: Benjamin Randazzo 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

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

2015-08-10T19:21:55+00:00

commit 34cab6f42003cb06f48f86a86652984dec338ae9 upstream.

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.")
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

Revert "dm: only run the queue on completion if congested or no requests pending"

2015-08-10T19:21:54+00:00

commit 621739b00e16ca2d80411dc9b111cb15b91f3ba9 upstream.

This reverts commit 9a0e609e3fd8a95c96629b9fbde6b8c5b9a1456a.
(Resolved a conflict during revert due to commit bfebd1cdb4 that came
after)

This revert is motivated by a couple failure reports on request-based DM
multipath testbeds:
1) Netapp reported that their multipath fault injection test under heavy
   IO load can stall longer than 300 seconds.
2) IBM reported elevated lock contention in their testbed (likely due to
   increased back pressure due to IO not being dispatched as quickly):
   https://www.redhat.com/archives/dm-devel/2015-July/msg00057.html

Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md: fix a build warning

2015-08-03T16:29:13+00:00

commit 4e023612325a9034a542bfab79f78b1fe5ebb841 upstream.

Warning like this:

drivers/md/md.c: In function "update_array_info":
drivers/md/md.c:6394:26: warning: logical not is only applied
to the left hand side of comparison [-Wlogical-not-parentheses]
      !mddev->persistent  != info->not_persistent||

Fix it as Neil Brown said:
mddev->persistent != !info->not_persistent ||

Signed-off-by: Firo Yang 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Skip cluster setup for dm-raid

2015-08-03T16:29:13+00:00

commit d3b178adb3a3adf54ecf77758138b654c3ee7f09 upstream.

There is a bug that the bitmap superblock isn't initialised properly for
dm-raid, so a new field can have garbage in new fields.
(dm-raid does initialisation in the kernel - md initialised the
 superblock in mdadm).

This means that for dm-raid we cannot currently trust the new ->nodes
field. So:
 - use __GFP_ZERO to initialise the superblock properly for all new
    arrays
 - initialise all fields in bitmap_info in bitmap_new_disk_sb
 - ignore ->nodes for dm arrays (yes, this is a hack)

This bug exposes dm-raid to bug in the (still experimental) md-cluster
code, so it is suitable for -stable.  It does cause crashes.

References: https://bugzilla.kernel.org/show_bug.cgi?id=100491
Signed-off-By: Goldwyn Rodrigues 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: unlock mddev_lock on an error path.

2015-08-03T16:29:13+00:00

commit 9a8c0fa861e4db60409b4dda254cef5e17e4d43c upstream.

This error path retuns while still holding the lock - bad.

Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.")
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: clear mddev->private when it has been freed.

2015-08-03T16:29:12+00:00

commit bd6919228d7e1867ae9e24ab27e3e4a366c87d21 upstream.

If ->private is set when ->run is called, it is assumed to be
a 'config'  prepared as part of 'reshape'.

So it is important when we free that config, that we also clear ->private.
This is not often a problem as the mddev will normally be discarded
shortly after the config us freed.
However if an 'assemble' races with a final close, the assemble can use
the old mddev which has a stale ->private.  This leads to any of
various sorts of crashes.

So clear ->private after calling ->free().

Reported-by: Nate Clark 
Fixes: afa0f557cb15 ("md: rename ->stop to ->free")
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

dm btree: silence lockdep lock inversion in dm_btree_del()

2015-08-03T16:29:07+00:00

commit 1c7518794a3647eb345d59ee52844e8a40405198 upstream.

Allocate memory using GFP_NOIO when deleting a btree.  dm_btree_del()
can be called via an ioctl and we don't want to recurse into the FS or
block layer.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman