used previously caused probe failure on platforms where char is unsigned
(e.g. ARM), as mftrecsz can be negative.
Submitted by: Ilya Bakulin <ilya@bakulin.de>
MFC after: 2 weeks
This will avoid a 0-byte read (in g_read_data()) leading to a panic, if
previously read data are erroneous.
Suggested by: John-Mark Gurney <jmg@funkthat.com>
Without this, read data is mis-interpreted. This could trigger a panic,
as was the case on one computer where computed "recsize" was zero,
leading to a call to g_read_page() asking for 0 bytes.
for specific "kinds" of disk labels - for example, GPT UUIDs. Reason
for this is that sometimes, other GEOM classes attach to these device
nodes instead of the proper ones - e.g. they attach to /dev/gptid/XXX
instead of /dev/ada0p2, which is annoying.
Reviewed by: pjd (earlier version)
MFC after: 1 month
