From: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
To: Frank van Maarseveen <frankvm@frankvm.com>
Cc: Bryan Henderson <hbryan@us.ibm.com>,
Arjan van de Ven <arjan@infradead.org>,
Jan Harkes <jaharkes@cs.cmu.edu>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Miklos Szeredi <miklos@szeredi.hu>, Pavel Machek <pavel@suse.cz>
Subject: Re: Finding hardlinks
Date: Mon, 8 Jan 2007 07:19:25 +0100 (CET) [thread overview]
Message-ID: <Pine.LNX.4.64.0701080717150.3506@artax.karlin.mff.cuni.cz> (raw)
In-Reply-To: <20070104001224.GA5980@janus>
>>> Currently, large file support is already necessary to handle dvd and
>>> video. It's also useful for images for virtualization. So the failing
>>> stat()
>>> calls should already be a thing of the past with modern distributions.
>>
>> As long as glibc compiles by default with 32-bit ino_t, the problem exists
>> and is severe --- programs handling large files, such as coreutils, tar,
>> mc, mplayer, already compile with 64-bit ino_t and off_t, but the user (or
>> script) may type something like:
>>
>> cat >file.c <<EOF
>> #include <sys/types.h>
>> #include <sys/stat.h>
>> main()
>> {
>> int h;
>> struct stat st;
>> if ((h = creat("foo", 0600)) < 0) perror("creat"), exit(1);
>> if (fstat(h, &st)) perror("stat"), exit(1);
>> close(h);
>> return 0;
>> }
>> EOF
>> gcc file.c; ./a.out
>>
>> --- and you certainly do not want this to fail (unless you are out of disk
>> space).
>>
>> The difference is, that with 32-bit program and 64-bit off_t, you get
>> deterministic failure on large files, with 32-bit program and 64-bit
>> ino_t, you get random failures.
>
> What's (technically) the problem with changing the gcc default?
Technically none (i.e. edit gcc specs or glibc includes). But persuading
all distribution builders to use this version is impossible. Plus there
are many binary programs that are unchangable.
> Alternatively we could make the error deterministic in various ways. Start
> st_ino numbering from 4G (except for a few special ones maybe such
> as root/mounts). Or make old and new programs look differently at the
> ELF level or by sys_personality() and/or check against a "ino64" mount
> flag/filesystem feature. Lots of possibilities.
I think the best solution would be to drop -EOVERFLOW on st_ino and let
legacy 32-bit programs live with coliding inodes. They'll have anyway.
Mikulas
next prev parent reply other threads:[~2007-01-08 6:19 UTC|newest]
Thread overview: 100+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-20 9:03 Finding hardlinks Mikulas Patocka
2006-12-20 11:44 ` Miklos Szeredi
2006-12-20 16:36 ` Mikulas Patocka
2006-12-20 16:50 ` Miklos Szeredi
2006-12-20 19:54 ` Al Viro
2006-12-20 20:12 ` Mikulas Patocka
2006-12-31 15:02 ` Mikulas Patocka
2006-12-21 18:58 ` Jan Harkes
2006-12-21 23:49 ` Mikulas Patocka
2006-12-22 5:05 ` Jan Harkes
2006-12-23 10:18 ` Arjan van de Ven
2006-12-23 14:00 ` Mikulas Patocka
2006-12-28 9:06 ` Benny Halevy
2006-12-28 10:05 ` Arjan van de Ven
2006-12-28 15:24 ` Benny Halevy
2006-12-28 19:58 ` Miklos Szeredi
2007-01-02 19:15 ` Pavel Machek
2007-01-02 20:41 ` Miklos Szeredi
2007-01-02 20:50 ` Mikulas Patocka
2007-01-02 21:10 ` Miklos Szeredi
2007-01-02 21:37 ` Mikulas Patocka
2007-01-03 11:56 ` Pavel Machek
2007-01-03 12:33 ` Miklos Szeredi
2007-01-03 12:42 ` Pavel Machek
2007-01-11 23:43 ` Denis Vlasenko
2007-01-03 12:45 ` Martin Mares
2007-01-03 13:54 ` Matthew Wilcox
2007-01-03 15:51 ` Miklos Szeredi
2007-01-03 19:04 ` Mikulas Patocka
2007-01-04 22:59 ` Pavel Machek
2007-01-05 8:43 ` Miklos Szeredi
2007-01-05 13:12 ` Pavel Machek
2007-01-05 13:55 ` Miklos Szeredi
2007-01-05 14:08 ` Mikulas Patocka
2007-01-05 15:09 ` Miklos Szeredi
2007-01-05 15:15 ` Miklos Szeredi
2007-01-08 11:27 ` Pavel Machek
2007-01-08 5:57 ` Mikulas Patocka
2007-01-08 8:49 ` Miklos Szeredi
2007-01-08 11:29 ` Pavel Machek
2007-01-08 12:00 ` Miklos Szeredi
2007-01-08 13:26 ` Martin Mares
2007-01-08 13:39 ` Miklos Szeredi
2007-01-09 16:26 ` Steven Rostedt
2007-01-09 19:53 ` Frank van Maarseveen
2007-01-09 20:11 ` Steven Rostedt
2007-01-11 10:07 ` Pádraig Brady
2007-01-05 17:30 ` Frank van Maarseveen
2006-12-28 18:14 ` Mikulas Patocka
2006-12-29 10:34 ` Trond Myklebust
2006-12-30 1:04 ` Mikulas Patocka
2007-01-01 2:30 ` Nikita Danilov
2007-01-01 22:58 ` Mikulas Patocka
2007-01-01 23:05 ` Nikita Danilov
2007-01-01 23:22 ` Mikulas Patocka
2007-01-04 13:59 ` Nikita Danilov
2007-01-02 23:14 ` Trond Myklebust
2007-01-02 23:50 ` Mikulas Patocka
2006-12-28 13:22 ` Jeff Layton
2006-12-28 15:12 ` Benny Halevy
2006-12-28 15:54 ` Jeff Layton
2006-12-28 16:26 ` Jan Engelhardt
2006-12-28 18:17 ` Mikulas Patocka
2006-12-28 20:07 ` Halevy, Benny
2006-12-29 10:28 ` [nfsv4] " Trond Myklebust
2006-12-31 21:25 ` Halevy, Benny
2007-01-02 23:21 ` Trond Myklebust
2007-01-03 12:35 ` Benny Halevy
2007-01-04 0:43 ` Trond Myklebust
2007-01-04 8:36 ` Trond Myklebust
2007-01-04 10:04 ` Benny Halevy
2007-01-04 10:47 ` Trond Myklebust
2007-01-05 8:28 ` Benny Halevy
2007-01-05 10:29 ` Trond Myklebust
2007-01-05 16:40 ` Nicolas Williams
2007-01-05 16:56 ` Trond Myklebust
2007-01-06 7:44 ` Halevy, Benny
2007-01-10 13:04 ` Benny Halevy
2006-12-29 10:12 ` Trond Myklebust
2006-12-31 21:19 ` Halevy, Benny
2007-01-02 23:20 ` Trond Myklebust
2007-01-02 23:46 ` Trond Myklebust
2007-01-11 23:35 ` Denis Vlasenko
2006-12-29 10:02 ` Pavel Machek
2007-01-01 22:47 ` Mikulas Patocka
2007-01-01 23:53 ` Jan Harkes
2007-01-02 0:04 ` Mikulas Patocka
2007-01-03 18:58 ` Frank van Maarseveen
2007-01-03 19:17 ` Mikulas Patocka
2007-01-03 19:26 ` Frank van Maarseveen
2007-01-03 19:31 ` Mikulas Patocka
2007-01-03 20:26 ` Frank van Maarseveen
2007-01-12 0:00 ` Denis Vlasenko
2007-01-03 22:30 ` Pavel Machek
2007-01-03 21:09 ` Bryan Henderson
2007-01-03 22:01 ` Frank van Maarseveen
2007-01-03 23:43 ` Mikulas Patocka
2007-01-04 0:12 ` Frank van Maarseveen
2007-01-08 6:19 ` Mikulas Patocka [this message]
[not found] <7x5mR-2wX-3@gated-at.bofh.it>
[not found] ` <7x9Ad-18O-35@gated-at.bofh.it>
[not found] ` <7yXEy-UI-39@gated-at.bofh.it>
[not found] ` <7yYKa-2Ds-3@gated-at.bofh.it>
[not found] ` <7zcWP-7ET-5@gated-at.bofh.it>
[not found] ` <7zdzA-jc-27@gated-at.bofh.it>
[not found] ` <7zeP5-2ic-15@gated-at.bofh.it>
[not found] ` <7zgH9-5my-17@gated-at.bofh.it>
[not found] ` <7zJSM-14t-9@gated-at.bofh.it>
[not found] ` <7zSW5-6cj-9@gated-at.bofh.it>
[not found] ` <7zX9l-4rS-7@gated-at.bofh.it>
[not found] ` <7zXMb-5g5-27@gated-at.bofh.it>
2007-01-05 23:54 ` Bodo Eggert
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Pine.LNX.4.64.0701080717150.3506@artax.karlin.mff.cuni.cz \
--to=mikulas@artax.karlin.mff.cuni.cz \
--cc=arjan@infradead.org \
--cc=frankvm@frankvm.com \
--cc=hbryan@us.ibm.com \
--cc=jaharkes@cs.cmu.edu \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=pavel@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).