Saw I/O errors while delete/create/attach a namespace on nvme device.

[Wen Xiong]

Hi All,

I am working on new nvme device and found this: nguid is changed while 
delete/create/attach a namespace, we saw some error messages in linux 
log.

Should we see these errors messages since recreating namespaces or are 
there some issues in error path?

# dmesg
[10524.330156] nvme nvme0: rescanning namespaces.
[10524.338810] nvme nvme0: identifiers changed for nsid 1
[10524.343448] block nvme0n1: no usable path - requeuing I/O
[10524.480468] block nvme0n1: no available path - failing I/O
[10524.480497] block nvme0n1: no available path - failing I/O
[10524.480501] Buffer I/O error on dev nvme0n1, logical block 781402912, 
async page read
[10524.480508] block nvme0n1: no available path - failing I/O
[10524.480510] Buffer I/O error on dev nvme0n1, logical block 781402913, 
async page read
[10524.480515] block nvme0n1: no available path - failing I/O
[10524.480517] Buffer I/O error on dev nvme0n1, logical block 781402914, 
async page read
[10524.480524] block nvme0n1: no available path - failing I/O
[10524.480525] Buffer I/O error on dev nvme0n1, logical block 781402915, 
async page read
[10524.480528] block nvme0n1: no available path - failing I/O
[10524.480529] Buffer I/O error on dev nvme0n1, logical block 781402916, 
async page read
[10524.480531] block nvme0n1: no available path - failing I/O
[10524.480535] Buffer I/O error on dev nvme0n1, logical block 781402917, 
async page read
[10524.480539] block nvme0n1: no available path - failing I/O
[10524.480541] Buffer I/O error on dev nvme0n1, logical block 781402918, 
async page read
[10524.480546] block nvme0n1: no available path - failing I/O
[10524.480548] Buffer I/O error on dev nvme0n1, logical block 781402919, 
async page read

Thanks for your help
Wendy