GNU bug report logs - #70877
guix-daemon fails to copy 4+GB file to store

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Ricardo Wurmus <rekado <at> elephly.net>
Subject: bug#70877: closed (Re: bug#70877: guix-daemon fails to copy 4+GB
 file to store)
Date: Mon, 13 May 2024 16:25:02 +0000

[Message part 1 (text/plain, inline)]

Your bug report

#70877: guix-daemon fails to copy 4+GB file to store

which was filed against the guix package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 70877 <at> debbugs.gnu.org.

-- 
70877: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=70877
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: Ludovic Courtès <ludo <at> gnu.org>
To: Ricardo Wurmus <rekado <at> elephly.net>
Cc: 70877-done <at> debbugs.gnu.org
Subject: Re: bug#70877: guix-daemon fails to copy 4+GB file to store
Date: Mon, 13 May 2024 18:24:22 +0200

Ludovic Courtès <ludo <at> gnu.org> skribis:

> Pushed as 7757fdd491862fa5c33f1f894503346b89898a01.
>
> I’ll update the ‘guix’ package to make the fix available.

Done in 58be9a79e2862d5fa9842d73f498ce2e5442b9ce.

Ludo'.

[Message part 3 (message/rfc822, inline)]

From: Ricardo Wurmus <rekado <at> elephly.net>
To: bug-guix <at> gnu.org
Subject: guix-daemon fails to copy 4+GB file to store
Date: Sat, 11 May 2024 12:52:53 +0200

[Message part 4 (text/plain, inline)]

The guix-daemon's libutil/util.cc uses copy_file_range to copy a
downloaded file into the store.  copy_file_range fails on files larger
than 4GB with an error like this:

    guix build: error: short write in copy_file_range `15' to `16': No such file or directory

The man page for copy_file_range says that it could return EFBIG when
the range exceeds the maximum range.  The daemon code does not check any
limits and will attempt to copy the whole file.

I believe our code ought to check the value of st.size and fall back to
a boring copy if it exceeds some "reasonable" value.

This is where copy_file_range is used:
https://git.savannah.gnu.org/cgit/guix.git/tree/nix/libutil/util.cc#n382

Here is a little reproducer:

[bug.scm (text/plain, inline)]

(use-modules (guix download)
             (guix packages)
             (guix build-system trivial))

(package
  (name "chungus")
  (version "1")
  (source
   (origin
     (method url-fetch)
     (uri "http://localhost:1111/chungus")
     (sha256
      (base32 "0nx67d4ls2nfwcfdmg81vf240z6lpwpdqypssr1wzn3hyz4szci4"))))
  (build-system trivial-build-system)
  (home-page "")
  (synopsis "")
  (description "")
  (license #f))

[Message part 6 (text/plain, inline)]

--8<---------------cut here---------------start------------->8---
# generate a big file
dd bs=1M count=4096 if=/dev/zero of=/tmp/chungus
# serve it
guix shell woof -- woof -i 127.0.0.1 -p 1111 -c 1 /tmp/chungus
# build the source derivation
guix build --no-grafts -Sf bug.scm
# observe the error
# guix build: error: short write in copy_file_range `15' to `16': No such file or directory
--8<---------------cut here---------------end--------------->8---

-- 
Ricardo

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.