Re: bin/50108 (fsck_ffs fails replaying wapbl journal on filesystem with 4k sectors)

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

The following reply was made to PR bin/50108; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/50108 (fsck_ffs fails replaying wapbl journal on filesystem with 4k sectors)
Date: Sun, 6 Sep 2015 08:19:40 +0000 (UTC)

 dholland-bugs%netbsd.org@localhost (David Holland) writes:
 
 > ...so, what else do we understand about how this PR is different from
 > 45933?
 
 45933 is caused by a bad superblock. The superblock encodes the
 physical sector size as seen by newfs. Userland tools like fsck
 use that information when reading a filesystem image. The kernel
 ignores that information, the disk driver has its own data to
 rely on.
 
 So when you make a filesystem image visible to multiple kernels
 (like in: Xen host vs. Xen guest) it doesn't matter. But the
 userland running under either kernel still cares.
 
 -- 
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                                 Michael van Elst
 Internet: mlelstv%serpens.de@localhost
                                 "A potential Snark may lurk in every tree."