Re: BUG:loop:blk_update_request: I/O error, dev loop6, sector 49674 op 0x9:(WRITE_ZEROES)

[Jens Axboe]

On 5/12/20 8:14 PM, Xu, Yanfei wrote:
> Hi,
> 
> After operating the /dev/loop which losetup with an image placed in**tmpfs,
> 
> I got the following ERROR messages:
> 
> ----------------[cut here]---------------------
> 
> [Â 183.110770] blk_update_request: I/O error, dev loop6, sector 524160 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.123949] blk_update_request: I/O error, dev loop6, sector 522 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.137123] blk_update_request: I/O error, dev loop6, sector 16906 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.150314] blk_update_request: I/O error, dev loop6, sector 32774 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.163551] blk_update_request: I/O error, dev loop6, sector 49674 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.176824] blk_update_request: I/O error, dev loop6, sector 65542 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.190029] blk_update_request: I/O error, dev loop6, sector 82442 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.203281] blk_update_request: I/O error, dev loop6, sector 98310 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.216531] blk_update_request: I/O error, dev loop6, sector 115210 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> [Â 183.229914] blk_update_request: I/O error, dev loop6, sector 131078 op 0x9:(WRITE_ZEROES) flags 0x1000800 phys_seg 0 prio class 0
> 
> 
> I have found the commit which introduce this issue by git bisect :
> 
> ÂÂÂ commit :efcfec57[loop: fix no-unmap write-zeroes request behavior]

Please CC the author of that commit too. Leaving the rest quoted below.

> Kernrel version: Linux version 5.6.0
> 
> Frequency: everytime
> 
> steps to reproduce:
> 
> Â 1.git clone mainline kernel
> 
> Â 2.compile kernel with ARCH=x86_64, and then boot the system with it
> 
> ÂÂÂ (seems other arch also can reproduce it )
> 
> Â 3.make an image by "dd of=/tmp/image if=/dev/zero bs=1M count=256"
> 
> Â *4.**place the image in tmpfs directory*
> 
> Â 5.losetup /dev/loop6 /PATH/TO/image
> 
> Â 6.mkfs.ext2 /dev/loop6
> 
> 
> Any comments will be appreciated.
> 
> 
> Thanks,
> 
> Yanfei
> 
> 
> 
> 
> 


-- 
Jens Axboe