[lvm-devel] master - lvconvert: Don't require a 'force' option during RAID repair.

[Marian Csontos]

Here is a bug against upstream LVM, so we keep track of this:

https://bugzilla.redhat.com/show_bug.cgi?id=1459566

-- Martian

On 06/07/2017 02:51 PM, Marian Csontos wrote:

> With this change applied, older kernels (7.2, RHEL6.x, F21) upconverting 
> linear to RAID1 now fails:
> 
> #lvchange-raid.sh:132+ lvconvert -y --type raid1 -m 1 @PREFIX at vg/LV1 
> /dev/mapper/@PREFIX at pv2
> device-mapper: raid: Device 1 specified for rebuild: Clearing superblock
> device-mapper: raid: 'rebuild' devices cannot be injected into an array 
> with other first-time devices
> device-mapper: table: 253:10: raid: Unable to assemble array: Invalid 
> superblocks
> device-mapper: ioctl: error adding target to table
> device-mapper: reload ioctl on  (253:10) failed: Invalid argument
>    Failed to lock logical volume @PREFIX at vg/LV1.
> 
> 
> Is this expected and should we skip these tests, or is there something 
> else going on?
> 
> -- Martian
> 
> On 06/06/2017 05:45 PM, Jonathan Brassow wrote:
>> Gitweb:        
>> https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=acaf3a5d47fd65b2e385a516544f8e6ec8d89b2d 
>>
>> Commit:        acaf3a5d47fd65b2e385a516544f8e6ec8d89b2d
>> Parent:        88e649628863e78b101c584c513053fc9461c24d
>> Author:        Jonathan Brassow <jbrassow at redhat.com>
>> AuthorDate:    Tue Jun 6 10:43:49 2017 -0500
>> Committer:     Jonathan Brassow <jbrassow at redhat.com>
>> CommitterDate: Tue Jun 6 10:43:49 2017 -0500
>>
>> lvconvert:  Don't require a 'force' option during RAID repair.
>>
>> Previously, we were treating non-RAID to RAID up-converts as a "resync"
>> operation.  (The most common example being 'linear -> RAID1'.)  RAID to
>> RAID up-converts or rebuilds of specific RAID images are properly treated
>> as a "recover" operation.
>>
>> Since we were treating some up-convert operations as "resync", it was
>> possible to have scenarios where data corruption or data loss were
>> possibilities if the RAID hadn't been able to sync completely before a
>> loss of the primary source devices.  In order to ensure that the user 
>> took
>> the proper precautions in such scenarios, we required a '--force' option
>> to be present.  Unfortuneately, the force option was rendered useless
>> because there was no way to distiguish the failure state of a potentially
>> destructive repair from a nominal one - making the '--force' option a
>> requirement for any repair!
>>
>> We now treat non-RAID to RAID up-converts properly as "recover" 
>> operations.
>> This eliminates the scenarios that can potentially cause data loss or
>> data corruption; and this eliminates the need for the '--force' 
>> requirement.
>> This patch removes the requirement to specify '--force' for RAID repairs.
>> ---
>>   lib/metadata/raid_manip.c |   31 +------------------------------
>>   1 files changed, 1 insertions(+), 30 deletions(-)
>>
>> diff --git a/lib/metadata/raid_manip.c b/lib/metadata/raid_manip.c
>> index 7e55530..08df32c 100644
>> --- a/lib/metadata/raid_manip.c
>> +++ b/lib/metadata/raid_manip.c
>> @@ -379,23 +379,6 @@ int lv_raid_in_sync(const struct logical_volume *lv)
>>       return _raid_in_sync(lv);
>>   }
>> -/* Check if RaidLV @lv is synced or any raid legs of @lv are not 
>> synced */
>> -static int _raid_devs_sync_healthy(struct logical_volume *lv)
>> -{
>> -    char *raid_health;
>> -
>> -    if (!_raid_in_sync(lv))
>> -        return 0;
>> -
>> -    if (!seg_is_raid1(first_seg(lv)))
>> -        return 1;
>> -
>> -    if (!lv_raid_dev_health(lv, &raid_health))
>> -        return_0;
>> -
>> -    return (strchr(raid_health, 'a') || strchr(raid_health, 'D')) ? 0 
>> : 1;
>> -}
>> -
>>   /*
>>    * _raid_remove_top_layer
>>    * @lv
>> @@ -2908,20 +2891,8 @@ static int _raid_extract_images(struct 
>> logical_volume *lv,
>>               if (!lv_is_on_pvs(seg_lv(seg, s), target_pvs) &&
>>                   !lv_is_on_pvs(seg_metalv(seg, s), target_pvs))
>>                   continue;
>> -
>> -            /*
>> -             * Kernel may report raid LV in-sync but still
>> -             * image devices may not be in-sync or faulty.
>> -             */
>> -            if (!_raid_devs_sync_healthy(lv) &&
>> -                (!seg_is_mirrored(seg) || (s == 0 && !force))) {
>> -                log_error("Unable to extract %sRAID image"
>> -                      " while RAID array is not in-sync%s.",
>> -                      seg_is_mirrored(seg) ? "primary " : "",
>> -                      seg_is_mirrored(seg) ? " (use --force option to 
>> replace)" : "");
>> -                return 0;
>> -            }
>>           }
>> +
>>           if (!_extract_image_components(seg, s, &rmeta_lv, 
>> &rimage_lv)) {
>>               log_error("Failed to extract %s from %s.",
>>                     display_lvname(seg_lv(seg, s)),
>>
>> -- 
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>>
> 
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