You have been subscribed to a public bug:

Command

  sudo mount -t vfat flop1 /mnt/flop1

fails. The image is readable but the log shows many I/O errors such as

May 12 07:57:24 us64a kernel: [69801.335823] print_req_error: I/O error, dev 
loop0, sector 0
May 12 07:57:24 us64a kernel: [69801.337707] print_req_error: I/O error, dev 
loop0, sector 0
May 12 07:57:24 us64a kernel: [69801.339521] FAT-fs (loop0): unable to read 
boot sector
May 12 07:57:24 us64a kernel: [69801.342063] print_req_error: I/O error, dev 
loop0, sector 0
May 12 07:57:24 us64a kernel: [69801.343891] Buffer I/O error on dev loop0, 
logical block 0, async page read
May 12 07:57:24 us64a kernel: [69801.345974] print_req_error: I/O error, dev 
loop0, sector 1
May 12 07:57:24 us64a kernel: [69801.347832] Buffer I/O error on dev loop0, 
logical block 1, async page read
May 12 07:57:24 us64a kernel: [69801.349928] print_req_error: I/O error, dev 
loop0, sector 2
May 12 07:57:24 us64a kernel: [69801.351818] Buffer I/O error on dev loop0, 
logical block 2, async page read
May 12 07:57:24 us64a kernel: [69801.356103] print_req_error: I/O error, dev 
loop0, sector 3
May 12 07:57:24 us64a kernel: [69801.356109] Buffer I/O error on dev loop0, 
logical block 3, async page read
May 12 07:57:24 us64a kernel: [69801.356117] print_req_error: I/O error, dev 
loop0, sector 4
May 12 07:57:24 us64a kernel: [69801.356119] Buffer I/O error on dev loop0, 
logical block 4, async page read
May 12 07:57:24 us64a kernel: [69801.356122] print_req_error: I/O error, dev 
loop0, sector 5
May 12 07:57:24 us64a kernel: [69801.356125] Buffer I/O error on dev loop0, 
logical block 5, async page read
May 12 07:57:24 us64a kernel: [69801.356128] print_req_error: I/O error, dev 
loop0, sector 6
May 12 07:57:24 us64a kernel: [69801.356130] Buffer I/O error on dev loop0, 
logical block 6, async page read
May 12 07:57:24 us64a kernel: [69801.356134] print_req_error: I/O error, dev 
loop0, sector 7
May 12 07:57:24 us64a kernel: [69801.356136] Buffer I/O error on dev loop0, 
logical block 7, async page read
May 12 07:57:24 us64a kernel: [69801.356260] Buffer I/O error on dev loop0, 
logical block 0, async page read
May 12 07:57:24 us64a kernel: [69801.356263] Buffer I/O error on dev loop0, 
logical block 1, async page read

The command, understandably, reports "can't read superblock on
/dev/loop0". The problem happens even on newly created images. Here's a
sample set of commands and responses:

$ mkfs.msdos -C flop1 1440
$ ls -l
-rwxrwxrwx 1 root root 1474560 May 10 18:49 flop1
$ hd flop1
<--- output looks reasonable including 55 aa and two FATs --->
$ sudo mkdir /mnt/flop1
$ sudo mount -o loop flop1 /mnt/flop1
mount: /mnt/flop1: can't read superblock on /dev/loop0.
$ losetup -f
/dev/loop0
$

I see plenty of reports of similar on different websites but without
resolution, including one on Launchpad but where the OP stopped
responding so it did not get resolved. I don't know when this problem
started to occur on this machine.

If it's relevant, this is running under VirtualBox which reports itself
as Version 5.2.26 r128414 (Qt5.6.2) with their 'host extensions'
enabled. However, mounting a floppy image previously worked on this
virtual machine.

I have rebooted with /forcefsck to check the root (and only) filesystem.
I have upgraded to the latest LTS Ubuntu, as below, but the problem
persists.

System info:

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.2 LTS
Release:        18.04
Codename:       bionic

Linux us64a 4.18.0-18-generic #19~18.04.1-Ubuntu SMP Fri Apr 5 10:22:13
UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

The machine is command-line only, i.e. no windowing.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: bot-comment
-- 
I/O errors when trying to loop mount an image
https://bugs.launchpad.net/bugs/1828712
You received this bug notification because you are a member of Kernel Packages, 
which is subscribed to linux in Ubuntu.

-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to