Re: [Qemu-devel] IDE disk FLUSH take more than 30 secs, the SUSE guest reports "lost interrupt and the file system becomes read-only"

[Andreas Färber]

Hi,

Am 21.05.2013 09:12, schrieb Gonglei (Arei):
> In the case of physical hard disk's speed which processing IO (when grouping 
> RAID) is very slow, I encountered a problem.
> I dd big file in SUSE virtual machine, the command is
> linux:/ # dd if=/dev/zero of=./info bs=1M count=5000;sync
> 
> but finally I get those message:
> linux:~ # dmesg
> [  174.804114] ata1: lost interrupt (Status 0x50)
> [  174.812305] end_request: I/O error, dev sda, sector 12085270
> [  174.812309] Buffer I/O error on device sda2, logical block 984530
> [  174.812310] lost page write due to I/O error on sda2
> [  174.813268] Aborting journal on device sda2.
> [  174.828330] journal commit I/O error
> [  174.828373] ext3_abort called.
> [  174.828375] EXT3-fs error (device sda2): ext3_journal_start_sb: Detected 
> aborted journal
> [  174.828377] Remounting filesystem read-only
> [  182.286424] __journal_remove_journal_head: freeing b_committed_data
> [  182.286434] __journal_remove_journal_head: freeing b_committed_data
> [  182.286442] __journal_remove_journal_head: freeing b_committed_data
> [  182.286452] __journal_remove_journal_head: freeing b_committed_data
> [  182.286472] __journal_remove_journal_head: freeing b_committed_data
> 
> 
> Through analysis, I found that because the system call the fdatasync command 
> in the Qemu over 30s,

Could you share your QEMU command line being used on the host? In
particular I'm wondering about -drive's cache option used - I've only
seen issues with cache=unsafe so far.

Is it an upstream qemu-system-x86_64 or a SLES qemu-kvm? What version?

Regards,
Andreas

> after the Guest's kernel thread detects the io transferation is timeout, went 
> to check IDE disk state. 
> But the IDE disk status is 0x50, rather than the BSY status, and then 
> departed error process...
> 
> the path of kernel's action is :
> scsi_softirq_done
>  scsi_eh_scmd_add
>    scsi_error_handler
>      shost->transportt->eh_strategy_handler 
>               ata_scsi_error 
>                       ap->ops->lost_interrupt
>                               ata_sff_lost_interrupt
> Finally, the file system becomes read-only.
> 
> Why not set the IDE disk for the BSY status When 0xe7 command is executed in 
> the Qemu?
> Anyone know it? thanks!
> 
> Best Regards!
> -Arei

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