Re: [linux-lvm] [PATCH] lvs: add -o lv_usable
On Tue, Sep 08, 2020 at 02:40:43PM +0800, heming.zhao wrote: > Does it acceptable to add new status bit in lv->status? > I ever sent it in previoud patch "[PATCH v2] lib/metadata: add new api > lv_is_available()" > The define as below (the 'NOT_AVAIL_LV' will change to 'NOT_USABLE_LV'): > ``` > +#define NOT_AVAIL_LV UINT64_C(0x8000)/* LV - derived flag, > not > +written out in > metadata*/ > > +#define lv_is_available(lv) (((lv)->status & NOT_AVAIL_LV) ? 0 : 1) > ``` > > some description about the new patch: > - it will combine with two patches: > - [PATCH v2] lib/metadata: add new api lv_is_available() > - [PATCH] lvs: add -o lv_usable > - the new patch will add new status bit NOT_USABLE_LV, and this bit will be > set in _lv_mark_if_partial_single(). > - The only output which related with new status bit: lvs -o lv_usable > > if above is acceptable, I will send the v2 patch. if not, I will give up this > 'lv_usable' patch. That sounds better, the old patch was closer to what we need. It can look at the PVs listed for the LV in the metadata, and check if those PVs have a device on the system (pv->dev is set) and are not flagged missing. device mapper state would not be needed for that (lv_mapping_table dm_has_lvdev functions are not needed.) To report info about the active state of LVs is more complex and requires different sort of code as Zdenek mentioned. Dave ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Re: [linux-lvm] [PATCH] lvs: add -o lv_usable
On 9/7/20 10:32 PM, Zdenek Kabelac wrote: Dne 05. 09. 20 v 11:08 heming.z...@suse.com napsal(a): On 9/5/20 5:06 PM, Zhao Heming wrote: report LV is usable for upper layer. Signed-off-by: Zhao Heming --- lib/activate/activate.h | 2 + lib/activate/dev_manager.c | 67 lib/metadata/metadata-exported.h | 1 + lib/metadata/metadata.c | 130 +++ lib/report/columns.h | 1 + lib/report/properties.c | 2 + lib/report/report.c | 13 lib/report/values.h | 1 + 8 files changed, 217 insertions(+) my test result: ## linear Hi We will need to take closer look - the patchset itself is not going in right direction - since all the info about missing or present devices is already available within lvm engine and we want to minimize 'repeated' query (ideally all the information should be checked only once - otherwise the decision state-machine is producing random-end result garbage - which is the very hard to trace and debug. So all the code which is doing runtime query again can't be accepted. Next main rule is - we cache status values whenever possible - so there should be at most 1 'status' per device per LV - but since lvm2 already knows from scanning point and from metadata parsing which device is missing the logic of evaluation of LV's usability needs to be based on these values. But I think we also need some per-segment methods evaluating usability. Regards Zdenek Hello Zdenek, Thank you for your review comments, I got your meaning. Does it acceptable to add new status bit in lv->status? I ever sent it in previoud patch "[PATCH v2] lib/metadata: add new api lv_is_available()" The define as below (the 'NOT_AVAIL_LV' will change to 'NOT_USABLE_LV'): ``` +#define NOT_AVAIL_LV UINT64_C(0x8000)/* LV - derived flag, not + written out in metadata*/ +#define lv_is_available(lv)(((lv)->status & NOT_AVAIL_LV) ? 0 : 1) ``` some description about the new patch: - it will combine with two patches: - [PATCH v2] lib/metadata: add new api lv_is_available() - [PATCH] lvs: add -o lv_usable - the new patch will add new status bit NOT_USABLE_LV, and this bit will be set in _lv_mark_if_partial_single(). - The only output which related with new status bit: lvs -o lv_usable if above is acceptable, I will send the v2 patch. if not, I will give up this 'lv_usable' patch. Thanks ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Re: [linux-lvm] [PATCH] lvs: add -o lv_usable
Dne 05. 09. 20 v 11:08 heming.z...@suse.com napsal(a): On 9/5/20 5:06 PM, Zhao Heming wrote: report LV is usable for upper layer. Signed-off-by: Zhao Heming --- lib/activate/activate.h | 2 + lib/activate/dev_manager.c | 67 lib/metadata/metadata-exported.h | 1 + lib/metadata/metadata.c | 130 +++ lib/report/columns.h | 1 + lib/report/properties.c | 2 + lib/report/report.c | 13 lib/report/values.h | 1 + 8 files changed, 217 insertions(+) my test result: ## linear Hi We will need to take closer look - the patchset itself is not going in right direction - since all the info about missing or present devices is already available within lvm engine and we want to minimize 'repeated' query (ideally all the information should be checked only once - otherwise the decision state-machine is producing random-end result garbage - which is the very hard to trace and debug. So all the code which is doing runtime query again can't be accepted. Next main rule is - we cache status values whenever possible - so there should be at most 1 'status' per device per LV - but since lvm2 already knows from scanning point and from metadata parsing which device is missing the logic of evaluation of LV's usability needs to be based on these values. But I think we also need some per-segment methods evaluating usability. Regards Zdenek ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Re: [linux-lvm] [PATCH] lvs: add -o lv_usable
On 9/5/20 5:06 PM, Zhao Heming wrote: > report LV is usable for upper layer. > > Signed-off-by: Zhao Heming > --- > lib/activate/activate.h | 2 + > lib/activate/dev_manager.c | 67 > lib/metadata/metadata-exported.h | 1 + > lib/metadata/metadata.c | 130 +++ > lib/report/columns.h | 1 + > lib/report/properties.c | 2 + > lib/report/report.c | 13 > lib/report/values.h | 1 + > 8 files changed, 217 insertions(+) > my test result: ## linear [tb-clustermd2 lvm2.sourceware.git]# vgcreate vg1 /dev/sdg /dev/sdi Physical volume "/dev/sdg" successfully created. Physical volume "/dev/sdi" successfully created. Volume group "vg1" successfully created [tb-clustermd2 lvm2.sourceware.git]# lvcreate -l 100%FREE -n lv1 vg1 Logical volume "lv1" created. [tb-clustermd2 lvm2.sourceware.git]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdg 8:96 0 100M 0 disk └─vg1-lv1 254:00 192M 0 lvm sdi 8:128 0 100M 0 disk └─vg1-lv1 254:00 192M 0 lvm vda 253:00 40G 0 disk ├─vda1253:108M 0 part ├─vda2253:20 38G 0 part / └─vda3253:302G 0 part [SWAP] -- remove one disk --- [tb-clustermd2 lvm2.sourceware.git]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdg 8:96 0 100M 0 disk └─vg1-lv1 254:00 192M 0 lvm vda 253:00 40G 0 disk ├─vda1253:108M 0 part ├─vda2253:20 38G 0 part / └─vda3253:302G 0 part [SWAP] [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -a -o name,devices,lv_usable,lv_health_status WARNING: Couldn't find device with uuid zOsVRm-ojxU-ZbfR-cLcT-MhxR-pfMh-eVfC42. WARNING: VG vg1 is missing PV zOsVRm-ojxU-ZbfR-cLcT-MhxR-pfMh-eVfC42 (last written to /dev/sdi). LV Devices Usable Health lv1 /dev/sdg(0) not usable partial lv1 [unknown](0) not usable partial [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -o name,devices,lv_usable,lv_health_status WARNING: Couldn't find device with uuid zOsVRm-ojxU-ZbfR-cLcT-MhxR-pfMh-eVfC42. WARNING: VG vg1 is missing PV zOsVRm-ojxU-ZbfR-cLcT-MhxR-pfMh-eVfC42 (last written to /dev/sdi). LV Devices Usable Health lv1 /dev/sdg(0) not usable partial lv1 [unknown](0) not usable partial - re-insert disk, but disk major:minor changed - [tb-clustermd2 lvm2.sourceware.git]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdg 8:96 0 100M 0 disk └─vg1-lv1 254:00 192M 0 lvm sdh 8:112 0 100M 0 disk vda 253:00 40G 0 disk ├─vda1253:108M 0 part ├─vda2253:20 38G 0 part / └─vda3253:302G 0 part [SWAP] [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -a -o name,devices,lv_usable,lv_health_status LV Devices Usable Health lv1 /dev/sdg(0) not usable lv1 /dev/sdh(0) not usable [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -o name,devices,lv_usable,lv_health_status LV Devices Usable Health lv1 /dev/sdg(0) not usable lv1 /dev/sdh(0) not usable ## mirror [tb-clustermd2 lvm2.sourceware.git]# lvcreate --type mirror -l 100%FREE -n mirrorlv vg1 Logical volume "mirrorlv" created. [tb-clustermd2 lvm2.sourceware.git]# lsblk NAMEMAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdg 8:96 0 100M 0 disk └─vg1-mirrorlv_mimage_0 254:10 92M 0 lvm └─vg1-mirrorlv254:30 92M 0 lvm sdh 8:112 0 100M 0 disk ├─vg1-mirrorlv_mlog 254:004M 0 lvm │ └─vg1-mirrorlv254:30 92M 0 lvm └─vg1-mirrorlv_mimage_1 254:20 92M 0 lvm └─vg1-mirrorlv254:30 92M 0 lvm vda 253:00 40G 0 disk ├─vda1 253:108M 0 part ├─vda2 253:20 38G 0 part / └─vda3 253:302G 0 part [SWAP] [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -a -o name,devices,lv_usable,lv_health_status LV Devices Usable Health mirrorlvmirrorlv_mimage_0(0),mirrorlv_mimage_1(0) usable [mirrorlv_mimage_0] /dev/sdg(0) usable [mirrorlv_mimage_1] /dev/sdh(0) usable [mirrorlv_mlog] /dev/sdh(23) usable [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -o name,devices,lv_usable,lv_health_status LV Devices Usable Health mirrorlv mirrorlv_mimage_0(0),mirrorlv_mimage_1(0) usable removed one disk - [tb-clustermd2 lvm2.sourceware.git]# ./tools/lvm lvs -a -o name,devices,lv_usable,lv_health_status WARNING: Couldn't find device with uuid
Re: [linux-lvm] [PATCH] lvs: add -o lv_usable
On 9/5/20 5:06 PM, Zhao Heming wrote: > report LV is usable for upper layer. > > Signed-off-by: Zhao Heming > --- > lib/activate/activate.h | 2 + > lib/activate/dev_manager.c | 67 > lib/metadata/metadata-exported.h | 1 + > lib/metadata/metadata.c | 130 +++ > lib/report/columns.h | 1 + > lib/report/properties.c | 2 + > lib/report/report.c | 13 > lib/report/values.h | 1 + > 8 files changed, 217 insertions(+) > There are some places need to improve. 1. in lib/activate/dev_manager.c, function lv_mapping_table() & dm_has_lvdev() almost same. it may merge into one function. 2. LV device-mapper name need to improve, in lib/metadata/metadata.c _lv_is_usable() I use below ugly code to construct dm name ``` /* format is right: "vgname" + '-' + "lvname" ?? */ snprintf(lvname, 50, "%s-%s", lv->vg->name, seg_lv(seg, s)->name); ... ... /* format is right: "vgname" + '-' + "lvname" ?? */ snprintf(lvname, 50, "%s-%s", lv->vg->name, lv->name); ``` Thanks ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
