mdadm: Fix Segmentation fault.

In function write_init_super1():
If "rv = store_super1(st, di->fd)" return error and the di is the last.
Then the di = NULL && rv > 0, so exec:
if (rv)
    fprintf(stderr, Name ": Failed to write metadata to%s\n",
     	 di->devname);
will be segmentation fault.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
imsm: fix: correct checking volume's degradation

We do not check the return value of sysfs_get_ll() now. It is wrong.
If reading of the sysfs "degraded" key does not succeed,
the "new_degraded" variable will not be initiated
and accidentally it can have the value of "degraded" variable.
In that case the change of degradation will not be checked.

It happens if mdadm is compiled with gcc's "-fstack-protector" option
when one tries to stop a volume under reshape (e.g. OLCE).
Reshape seems to be finished then (metadata is in normal/clean state)
but it is not finished, it is broken and data are corrupted.

Now we always check the return value of sysfs_get_ll().
Even if reading of the sysfs "degraded" key does not succeed
(rv == -1) the change of degradation will be checked.

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Fix --no-error in test script

b8e91a32cdaa2a6dea8b0dd54365ede33d5a9a60 was applied incorrectly.
It changed the name of the variable set when specifying --no-error,
without changing the places checking it.

Set it back as it was to make --no-error work correctly again.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
New tests testing the addition of bitmaps

This set of tests verifies that it is possible to add an internal
bitmap to an existing array, and that the device can be written to
after the bitmap is added. This should catch cases such as the one
fixed by 4474ca42e2577563a919fd3ed782e2ec55bf11a2

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
New tests testing removal of internal bitmaps

To match the add-bitmap tests, here is a set of tests checking the
removal of bitmaps.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Detail: show which 'set' each device in a RAID10 belongs to

A RAID10 can be though of as having 2 sets of devices
(if there are 2 copies and an even number of devices in total).

With this patch "mdadm --detail" shows which 'set' each device
belongs to - set-A or set-B.

If there are more than 3 copies, there can be more than 3 sets.

If the number of copies does not evenly divide the number of devices,
there are not distinct 'sets' so none are reported.

Signed-off-by: NeilBrown <neilb@suse.de>
Monitor: Allow correct monitoring of more member devices.

Having "MaxDisks == 384" is not good.  Discard it in favour of
MAX_DISKS which is 4096

Signed-off-by: NeilBrown <neilb@suse.de>
Monitor: fix inconsistencies in values for ->percent

->percent sometimes stores negative values recording states
like 'pending' or 'delayed'.
The value '-2' means both 'delayed' and in Monitor, 'unknown'.
Also, '-1' has a meaning but not #define.

So change the #defines to be prefixed with "RESYNC_", instead
of "PROCESS_", add new "_NONE" and "_UNKNOWN", and use correct
value in each location.

Signed-off-by: NeilBrown <neilb@suse.de>
Monitor: Report NewArray when an array the disappeared, reappears.


Signed-off-by: NeilBrown <neilb@suse.de>
Monitor: fix reporting for Fail vs FailSpare etc.

The tests here were specific to 0.90 metadata and didn't
work properly for 1.x metadata, where a device's "number"
doesn't change.

By checking if this is a new array we can avoid some
corner cases.  Then we test mostly based on state and
not based on 'number' at all.

Signed-off-by: NeilBrown <neilb@suse.de>