Re: kern/55674: ld(4) should attempt to allocate ld(4) for 0 size disks

[mlelstv%serpens.de@localhost (Michael van Elst)]

The following reply was made to PR kern/55674; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/55674: ld(4) should attempt to allocate ld(4) for 0 size disks
Date: Mon, 21 Sep 2020 10:51:59 -0000 (UTC)

 kardel%netbsd.org@localhost (Frank Kardel) writes:
 
 >> nvmectl identify nvme0ns2
 >> Size (in LBAs):              0 (0M)
 >> Capacity (in LBAs):          0 (0M)
 >> Utilization (in LBAs):       0 (0M)
 >> Thin Provisioning:           Not Supported
 >> Number of LBA Formats:       1
 >> Current LBA Format:          LBA Format #00
 >> LBA Format #00: Data Size:     1  Metadata Size:     0
 
 A size of zero is perfectly valid, but a "data size" of 1 (byte per block)
 is invalid.
 
 The ld(4) attachment already fails with that data size, but since this
 happens within the attach routine that cannot signal failure, the ld(4)
 units are still created.
 
 A workaround would be to issue the identify command and check the format
 already in the nvme driver. As long as ld(4) is the only child for nvme
 this shouldn't cause any problems.
 
 -- 
 -- 
                                 Michael van Elst
 Internet: mlelstv%serpens.de@localhost
                                 "A potential Snark may lurk in every tree."