[linux-lvm] (resend) may bug: lvconvert reports "Insufficient free space" when doing "--replace"

[heming.zhao at suse.com]

(I sent this mail some days before, it looks this mail was blocked by anti-spam system. resend it)

Hello list,

I may found a bug, when lv is raid1, and each leg includes more than one PV.

When doing "lvconvert --replace" to replace one of the oldpv with a newpv,
It looks lvconvert requires full raid array size for a single newpv.

lvm version: 2.03.12, Reproducible steps:

```
# vgcreate vg1 /dev/sdg /dev/sdh
   Volume group "vg1" successfully created

# lvcreate -n lv1 -l 90%FREE vg1
   Logical volume "lv1" created.

# vgextend vg1 /dev/sdj /dev/sdk
   Physical volume "/dev/sdj" successfully created.
   Physical volume "/dev/sdk" successfully created.
   Volume group "vg1" successfully extended

# lvconvert --type raid1 vg1/lv1 /dev/sdg /dev/sdh /dev/sdj /dev/sdk
Are you sure you want to convert linear LV vg1/lv1 to raid1 type? [y/n]: y
   Logical volume vg1/lv1 successfully converted.

# lsblk
NAME               MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sdg                  8:96   0  200M  0 disk
└─vg1-lv1_rimage_0 254:4    0  352M  0 lvm
   └─vg1-lv1        254:2    0  352M  0 lvm
sdh                  8:112  0  200M  0 disk
├─vg1-lv1_rmeta_0  254:3    0    4M  0 lvm
│ └─vg1-lv1        254:2    0  352M  0 lvm
└─vg1-lv1_rimage_0 254:4    0  352M  0 lvm
   └─vg1-lv1        254:2    0  352M  0 lvm
sdi                  8:128  0  200M  0 disk
sdj                  8:144  0  200M  0 disk
├─vg1-lv1_rmeta_1  254:5    0    4M  0 lvm
│ └─vg1-lv1        254:2    0  352M  0 lvm
└─vg1-lv1_rimage_1 254:6    0  352M  0 lvm
   └─vg1-lv1        254:2    0  352M  0 lvm
sdk                  8:160  0  200M  0 disk
└─vg1-lv1_rimage_1 254:6    0  352M  0 lvm
   └─vg1-lv1        254:2    0  352M  0 lvm
sdl                  8:176  0  200M  0 disk

# vgextend vg1 /dev/sdi
   Volume group "vg1" successfully extended

# lvconvert --replace /dev/sdh vg1/lv1 /dev/sdi  (<=== failed, should succeed)
   Insufficient free space: 89 extents needed, but only 49 available
   LV vg1/lv1 in not partial.

# lvconvert --replace /dev/sdg vg1/lv1 /dev/sdi   (<=== failed, should succeed)
   Insufficient free space: 89 extents needed, but only 49 available
   LV vg1/lv1 in not partial.

# pvmove /dev/sdh /dev/sdi
   /dev/sdh: Moved: 2.50%
   /dev/sdh: Moved: 100.00%
```

pvmove is workable, but I think it's a work around.
lvconvert should run successfully with above cmds.

Thanks,
Heming