Re: misc/33753 (don't installworld to a full disk)

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

The following reply was made to PR misc/33753; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: misc/33753 (don't installworld to a full disk)
Date: Sun, 28 May 2023 06:59:35 -0000 (UTC)

 dholland%NetBSD.org@localhost writes:
 
 >Synopsis: don't installworld to a full disk
 
 >State-Changed-From-To: feedback->open
 >State-Changed-By: dholland%NetBSD.org@localhost
 >State-Changed-When: Sun, 28 May 2023 05:45:42 +0000
 >State-Changed-Why:
 >I don't remember what I was thinking in 2006, and any diagnosis I did
 >then would have ended up in here (thus, little or none) so IDK. But
 >remember that installworld runs by creating and unpacking sets, not
 >install(1), so the problem is probably somewhere in the tar/pax/whatnot
 >borg. Or was. And probably the problem was total failure to detect
 >write errors at all.
 
 >Whether this is still current I have no idea; it should be possible to
 >test it with a scratch partition.
 
 From the copy function of pax:
 
                 if ((fddest = file_creat(arcn, 0)) < 0) {
                         rdfile_close(arcn, &fdsrc);
                         purg_lnk(arcn);
                         continue;
                 }
 
                 cp_file(arcn, fdsrc, fddest);
                 file_close(arcn, fddest);
 
 
 file_creat creates a temporary file.
 cp_file copies the data.
 file_close closes the destination and renames it.
 
 However, any kind of error during the copy or close (like disk full)
 just produces a warning, it doesn't prevent the operation from being
 aborted or the old file from being kept.