Bug 1144546

Summary:	btrfs - mount external drive via USB fails with superblock can't be read
Product:	[openSUSE] openSUSE Tumbleweed	Reporter:	Mario Penzel <penc>
Component:	Kernel	Assignee:	Wenruo Qu <wqu>
Status:	RESOLVED FIXED	QA Contact:	E-mail List <qa-bugs>
Severity:	Normal
Priority:	P5 - None	CC:	jeffm
Version:	Current
Target Milestone:	---
Hardware:	x86-64
OS:	openSUSE Factory
Whiteboard:
Found By:	---	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description Mario Penzel 2019-08-06 16:38:15 UTC

not sure, when this was introduced - back to kernel 5.2.4 same situation

mounting same device on a stable Leap 15.0 (VM on same host) works. Also different rescue / checking with btrfs-tools do not show any problems. Superblock and all copies are valid.


affected system (host):
=======================

Linux 5.2.6-1.g187170c-default #1 SMP Sun Aug 4 15:14:38 UTC 2019 (187170c) x86_64 GNU/Linux
btrfs-progs v5.1

dmesg - output:

(1) plug in USB storage-device:
...
[25401.785475] usb 1-2: new high-speed USB device number 5 using xhci_hcd 
[25401.934546] usb 1-2: New USB device found, idVendor=04e8, idProduct=6034, bcdDevice= 0.00 
[25401.934551] usb 1-2: New USB device strings: Mfr=1, Product=11, SerialNumber=3 
[25401.934555] usb 1-2: Product: Samsung G2 Portable 
[25401.934557] usb 1-2: Manufacturer: JMicron 
[25401.934560] usb 1-2: SerialNumber: 00000011E09310C0005C 
[25401.936277] usb-storage 1-2:1.0: USB Mass Storage device detected 
[25401.936591] scsi host4: usb-storage 1-2:1.0 
[25402.385579] usb 1-2: reset high-speed USB device number 5 using xhci_hcd 
...

(2) try to mount the device:

sudo mount /dev/sdb1 /tmp --verbose 
mount: /tmp: Der Superblock von /dev/sdb1 konnte nicht gelesen werden.

dmesg - output:
...
[25440.914136] usb 1-2: reset high-speed USB device number 5 using xhci_hcd 
[25441.063783] usb-storage 1-2:1.0: USB Mass Storage device detected
[25441.064320] scsi host4: usb-storage 1-2:1.0 
[25442.090390] scsi 4:0:0:0: Direct-Access     Samsung  G2 Portable           PQ: 0 ANSI: 2 CCS 
[25442.091044] sd 4:0:0:0: Attached scsi generic sg1 type 0 
[25442.091288] sd 4:0:0:0: [sdb] 1250263728 512-byte logical blocks: (640 GB/596 GiB) 
[25442.091782] sd 4:0:0:0: [sdb] Write Protect is off 
[25442.091787] sd 4:0:0:0: [sdb] Mode Sense: 3c 00 00 00 
[25442.092234] sd 4:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA 
[25442.093668]  sdb: sdb1 
[25442.095245] sd 4:0:0:0: [sdb] Attached SCSI disk 
[25451.570591] BTRFS info (device sdb1): disk space caching is enabled 
[25452.014781] BTRFS info (device sdb1): bdev /dev/sdb1 errs: wr 2, rd 0, flush 0, corrupt 0, gen 0 
[25453.817230] BTRFS critical (device sdb1): corrupt leaf: root=5 block=6576889856 slot=10 ino=265, invalid inode generation: has 18446744073709551492 expect [0, 17248] 
[25453.817240] BTRFS error (device sdb1): block=6576889856 read time tree block corruption detected 
...

===============================================================================


test-case system (VM guest):
============================

Linux 4.12.14-lp150.12.67-default #1 SMP Tue Jul 9 08:18:26 UTC 2019 (b610084) x86_64 GNU/Linux
btrfs-progs v4.15

(1) autoplug the device to VM

dmesg-output:
...
[    2.768209] usb 1-2: new high-speed USB device number 3 using xhci_hcd 
[    3.204950] usb 1-2: New USB device found, idVendor=04e8, idProduct=6034 
[    3.204955] usb 1-2: New USB device strings: Mfr=1, Product=11, SerialNumber=3 
[    3.204959] usb 1-2: Product: Samsung G2 Portable 
[    3.204961] usb 1-2: Manufacturer: JMicron 
[    3.204964] usb 1-2: SerialNumber: 00000011E09310C0005C 
[    3.214198] usb-storage 1-2:1.0: USB Mass Storage device detected
[    3.215805] scsi host4: usb-storage 1-2:1.0 
[    3.215957] usbcore: registered new interface driver usb-storage 
[    3.218192] usbcore: registered new interface driver uas 
 
[    4.163485] systemd: 19 output lines suppressed due to ratelimiting 
[    4.222281] scsi 4:0:0:0: Direct-Access     Samsung  G2 Portable           PQ: 0 ANSI: 2 CCS 
[    4.222708] sd 4:0:0:0: Attached scsi generic sg2 type 0 
[    4.224492] sd 4:0:0:0: [sdb] 1250263728 512-byte logical blocks: (640 GB/596 GiB) 
[    4.226021] sd 4:0:0:0: [sdb] Write Protect is off 
[    4.226025] sd 4:0:0:0: [sdb] Mode Sense: 3c 00 00 00 
[    4.227906] sd 4:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA 
[    7.349640]  sdb: sdb1
...

(2) mount device to userspace

dmesg-output:
...
[  130.285374] BTRFS info (device sdb1): disk space caching is enabled 
[  130.406519] BTRFS info (device sdb1): bdev /dev/sdb1 errs: wr 2, rd 0, flush 0, corrupt 0, gen 0

Comment 3 Wenruo Qu 2019-12-23 01:22:47 UTC

Since the bug is caused by bad fs, and now we have a btrfs wiki for it, it should be good enough for end-users.

Comment 4 Wenruo Qu 2019-12-23 01:24:17 UTC

Latest btrfs-progs should have been able to fix the generation problem. Closing.