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Bug 1066977

Summary:	lvm2 calculates snapshot space incorrectly
Product:	Red Hat Enterprise Linux 7	Reporter:	Zdenek Kabelac <zkabelac>
Component:	lvm2	Assignee:	LVM and device-mapper development team <lvm-team>
lvm2 sub component:	Default / Unclassified	QA Contact:	cluster-qe <cluster-qe>
Status:	CLOSED CURRENTRELEASE	Docs Contact:
Severity:	high
Priority:	high	CC:	agk, cmarthal, coughlan, dwysocha, heinzm, jbrassow, mpatocka, msnitzer, prajnoha, prockai, thornber, zkabelac
Version:	7.0	Keywords:	Triaged
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	lvm2-2.02.105-8.el7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1035871	Environment:
Last Closed:	2014-06-13 11:04:06 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1035871
Bug Blocks:

Comment 2 Zdenek Kabelac 2014-02-26 13:58:10 UTC

Upstreamed updated version of Mikulas' patch:

http://www.redhat.com/archives/lvm-devel/2014-February/msg00161.html

Comment 5 Peter Rajnoha 2014-02-27 13:17:08 UTC

One more patch needed for a fix here, it's included in lvm2-2.02.105-8.el7.

Comment 6 Zdenek Kabelac 2014-03-06 16:38:45 UTC

Upstream test case:

https://www.redhat.com/archives/lvm-devel/2014-March/msg00045.html

Comment 7 Corey Marthaler 2014-03-21 16:17:46 UTC

Fix verified in the latest rpms.

3.10.0-110.el7.x86_64
lvm2-2.02.105-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
lvm2-libs-2.02.105-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
lvm2-cluster-2.02.105-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
device-mapper-1.02.84-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
device-mapper-libs-1.02.84-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
device-mapper-event-1.02.84-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
device-mapper-event-libs-1.02.84-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014
device-mapper-persistent-data-0.2.8-4.el7    BUILT: Fri Jan 24 14:28:55 CST 2014
cmirror-2.02.105-13.el7    BUILT: Wed Mar 19 05:38:19 CDT 2014



BEFORE FIX:

[root@harding-03 ~]# lvcreate -L 2143289344b -n origin VG
  Logical volume "origin" created
[root@harding-03 ~]# lvcreate -n snap -c 8k -L 2304M -s VG/origin
  Reducing COW size 2.25 GiB down to maximum usable size 2.00 GiB.
WARNING: DM_snapshot_cow signature detected on /dev/VG/snap at offset 0. Wipe it? [y/n] y
  Wiping DM_snapshot_cow signature on /dev/VG/snap.
  Logical volume "snap" created
[root@harding-03 ~]# lvs -a -o +devices
  LV     VG  Attr       LSize  Origin Data%  Devices         
  origin VG  owi-a-s---  2.00g               /dev/sdb1(0)    
  snap   VG  swi-a-s---  2.00g origin   0.00 /dev/sdb1(511)  
[root@harding-03 ~]# dd if=/dev/zero of=/dev/VG/snap bs=1M oflag=direct
dd: error writing ‘/dev/VG/snap’: Input/output error
2044+0 records in
2043+0 records out
2142240768 bytes (2.1 GB) copied, 16.9193 s, 127 MB/s
[root@harding-03 ~]# dd if=/dev/VG/snap of=/tmp/foofile  bs=1M oflag=direct count=100
dd: error reading ‘/dev/VG/snap’: Input/output error
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.0694476 s, 0.0 kB/s
[root@harding-03 ~]# lvs -a -o +devices
  /dev/VG/snap: read failed after 0 of 4096 at 2143223808: Input/output error
  /dev/VG/snap: read failed after 0 of 4096 at 2143281152: Input/output error
  /dev/VG/snap: read failed after 0 of 4096 at 0: Input/output error
  /dev/VG/snap: read failed after 0 of 4096 at 4096: Input/output error
  LV     VG  Attr       LSize  Origin Data%  Devices         
  origin VG  owi-a-s---  2.00g               /dev/sdb1(0)    
  snap   VG  swi-I-s---  2.00g origin 100.00 /dev/sdb1(511)  

harding-03 kernel: [58068.989183] attempt to access beyond end of device
harding-03 kernel: [58068.994580] dm-6: rw=17, want=4194312, limit=4194304
harding-03 kernel: [58069.000148] attempt to access beyond end of device
harding-03 kernel: [58069.005517] dm-6: rw=17, want=4194320, limit=4194304
harding-03 kernel: [58069.011220] device-mapper: snapshots: Invalidating snapshot: Error reading/writing.
harding-03 kernel: [58069.027895] quiet_error: 55 callbacks suppressed
harding-03 kernel: [58069.034257] Buffer I/O error on device dm-4, logical block 523248
harding-03 kernel: [58069.041097] Buffer I/O error on device dm-4, logical block 523248
harding-03 kernel: [58069.049475] Buffer I/O error on device dm-4, logical block 523262
harding-03 kernel: [58069.057849] Buffer I/O error on device dm-4, logical block 523262
harding-03 kernel: [58069.064682] Buffer I/O error on device dm-4, logical block 0
harding-03 kernel: [58069.071025] Buffer I/O error on device dm-4, logical block 0
harding-03 kernel: [58069.077357] Buffer I/O error on device dm-4, logical block 1
harding-03 kernel: [58069.083705] Buffer I/O error on device dm-4, logical block 523263
harding-03 kernel: [58069.090536] Buffer I/O error on device dm-4, logical block 523263
harding-03 kernel: [58069.098881] Buffer I/O error on device dm-4, logical block 523263
harding-03 kernel: [58104.501653] quiet_error: 146 callbacks suppressed



AFTER FIX:

[root@harding-02 ~]# lvcreate -L 2143289344b -n origin VG
  Logical volume "origin" created
[root@harding-02 ~]# lvcreate -n snap -c 8k -L 2304M -s VG/origin
  Reducing COW size 2.25 GiB down to maximum usable size 2.00 GiB.
  Logical volume "snap" created
[root@harding-02 ~]# lvs -a -o +devices
  LV     VG  Attr       LSize  Origin Data%  Devices         
  origin VG  owi-a-s---  2.00g               /dev/sdb1(0)    
  snap   VG  swi-a-s---  2.00g origin   0.00 /dev/sdb1(511)  
[root@harding-02 ~]# dd if=/dev/zero of=/dev/VG/snap bs=1M oflag=direct
dd: error writing ‘/dev/VG/snap’: No space left on device
2045+0 records in
2044+0 records out
2143289344 bytes (2.1 GB) copied, 16.9464 s, 126 MB/s
[root@harding-02 ~]# dd if=/dev/VG/snap of=/tmp/foofile  bs=1M oflag=direct count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB) copied, 0.90842 s, 115 MB/s
[root@harding-02 ~]# lvs -a -o +devices
  LV     VG  Attr       LSize  Origin Data%  Devices         
  origin VG  owi-a-s---  2.00g               /dev/sdb1(0)    
  snap   VG  swi-a-s---  2.00g origin  99.81 /dev/sdb1(511)

Comment 8 Ludek Smid 2014-06-13 11:04:06 UTC

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.