kern/163076: It is not possible to read in chunks from linprocfs and procfs.

[Jaakko Heinonen]

The following reply was made to PR kern/163076; it has been noted by GNATS.

From: Jaakko Heinonen <jh at FreeBSD.org>
To: Petr Salinger <Petr.Salinger at seznam.cz>,
	Poul-Henning Kamp <phk at phk.freebsd.dk>
Cc: Dag-Erling =?utf-8?B?U23DuHJncmF2?= <des at des.no>,
	bug-followup at FreeBSD.org, mdf at FreeBSD.org
Subject: Re: kern/163076: It is not possible to read in chunks from linprocfs
 and procfs.
Date: Fri, 16 Dec 2011 10:19:35 +0200

 On 2011-12-13, Petr Salinger wrote:
 > Will be this regression corrected for 9.0 release ?
 
 AFAIK it's too late to get such patch approved for 9.0.
 
 > Previously (in stable-8), the sbuf_finish() cleared the overflow error.
 > It used to return void, and as noted previously,
 > only 21 of 133 calls check return value of sbuf_finish(),
 > i.e. only 1/6 have been migrated to new API semantics.
 > 
 > What about restore clearing of error during sbuf_finish() for stable-9
 > and do the right thing in HEAD ?
 
 If nobody can suggest a better alternative, I am inclined to say that
 I'd like to see the change reverted until someone volunteers to fix
 callers.
 
 I don't say that r222004 is incorrect but the fact is that sbuf_finish()
 didn't return an error for a long time (almost 10 years) and when the
 API was changed it looks like API consumers weren't changed along.
 
 I am willing to help but currently I have no idea how to fix pseudofs
 with the new API semantics. I don't like the patch posted because it
 allocates an excessively large buffer on every read.
 
 -- 
 Jaakko