LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Andi Kleen <ak@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>,
	Steve French <smfrench@gmail.com>,
	swhiteho@redhat.com, sfrench@samba.org, vandrove@vc.cvut.cz,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] [8/18] BKL-removal: Remove BKL from remote_llseek
Date: Mon, 28 Jan 2008 09:17:52 +0100	[thread overview]
Message-ID: <200801280917.52574.ak@suse.de> (raw)
In-Reply-To: <20080127211345.6e73fa0b.akpm@linux-foundation.org>


> I completely agree.  If one thread writes A and another writes B then the
> kernel should record either A or B, not ((A & 0xffffffff00000000) | (B &
> 0xffffffff))

The problem is pretty nasty unfortunately. To solve it properly I think
the file_operations->read/write prototypes would need to be changed
because otherwise it is not possible to do atomic relative updates
of f_pos. Right now the actual update is burrowed deeply in the low level 
read/write implementation. But that would be a huge impact all over
the tree :/

Or maybe define a new read/write64 and keep the default as 32bit only-- i 
suppose most users don't really need 64bit. Still would be a nasty API 
change.

-Andi

  reply	other threads:[~2008-01-28  8:19 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-27  2:17 [PATCH] [0/18] Implement some low hanging BKL removal fruit in fs/* Andi Kleen
2008-01-27  2:17 ` [PATCH] [1/18] BKL-removal: Convert ext2 over to use unlocked_ioctl Andi Kleen
2008-01-27  2:17 ` [PATCH] [2/18] BKL-removal: Remove incorrect BKL comment in ext2 Andi Kleen
2008-01-27  2:17 ` [PATCH] [3/18] BKL-removal: Convert ext3 to use unlocked_ioctl Andi Kleen
2008-01-28  5:33   ` Andrew Morton
2008-01-28  6:02     ` Andi Kleen
2008-01-27  2:17 ` [PATCH] [4/18] ext3: Remove incorrect BKL comment Andi Kleen
2008-01-27  2:17 ` [PATCH] [5/18] BKL-removal: Remove incorrect comment refering to lock_kernel() from jbd/jbd2 Andi Kleen
2008-01-27  2:17 ` [PATCH] [6/18] BKL-removal: Convert ext4 to use unlocked_ioctl Andi Kleen
2008-01-27  2:17 ` [PATCH] [7/18] BKL-removal: Remove incorrect comments refering to BKL from ext4 Andi Kleen
2008-01-27  2:17 ` [PATCH] [8/18] BKL-removal: Remove BKL from remote_llseek Andi Kleen
2008-01-27 16:57   ` Steve French
2008-01-27 17:56     ` Trond Myklebust
2008-01-27 22:18       ` Steve French
2008-01-27 23:08         ` Trond Myklebust
2008-01-28  2:58           ` Andi Kleen
2008-01-28  4:13             ` Trond Myklebust
2008-01-28  4:38               ` Andi Kleen
2008-01-28  4:51                 ` Trond Myklebust
2008-01-28  5:13                 ` Andrew Morton
2008-01-28  8:17                   ` Andi Kleen [this message]
2008-01-28 18:33                     ` Steve French
2008-01-28 19:34                       ` Dave Kleikamp
2008-01-28 12:56                   ` Alan Cox
2008-01-28 13:27                     ` Andi Kleen
2008-01-28 13:38                       ` Alan Cox
2008-01-28 14:10                         ` Andi Kleen
2008-01-28 14:50                           ` Alan Cox
2008-01-28 15:13                           ` Diego Calleja
2008-01-28  2:44         ` Andi Kleen
2008-01-28  2:43     ` Andi Kleen
2008-01-27  2:17 ` [PATCH] [9/18] BKL-removal: Use unlocked_ioctl for jfs Andi Kleen
2008-01-27 23:05   ` Dave Kleikamp
2008-01-27  2:17 ` [PATCH] [10/18] BKL-removal: Implement a compat_ioctl handler for JFS Andi Kleen
2008-01-27 23:05   ` Dave Kleikamp
2008-01-27  2:17 ` [PATCH] [11/18] BKL-removal: Convert ocfs2 over to unlocked_ioctl Andi Kleen
2008-01-27  2:17 ` [PATCH] [12/18] BKL-removal: Convert CIFS " Andi Kleen
2008-01-27  2:17 ` [PATCH] [13/18] BKL-removal: Add compat_ioctl for cifs Andi Kleen
2008-01-27  2:17 ` [PATCH] [14/18] BKL-removal: Add unlocked_fasync Andi Kleen
2008-01-27  7:05   ` KOSAKI Motohiro
2008-01-27  2:17 ` [PATCH] [15/18] BKL-removal: Convert pipe over to unlocked_fasync Andi Kleen
2008-01-27  2:17 ` [PATCH] [16/18] BKL-removal: Convert socket fasync " Andi Kleen
2008-01-27  2:17 ` [PATCH] [17/18] BKL-removal: Convert fuse " Andi Kleen
2008-01-27  2:17 ` [PATCH] [18/18] BKL-removal: Convert bad_inode " Andi Kleen
2008-01-28  1:59 ` [PATCH] [0/18] Implement some low hanging BKL removal fruit in fs/* Nick Piggin
2008-01-28  3:15   ` Andi Kleen
     [not found] <9Q5hR-3MI-9@gated-at.bofh.it>
     [not found] ` <9Qsob-7is-1@gated-at.bofh.it>
     [not found]   ` <9QtDz-121-11@gated-at.bofh.it>
     [not found]     ` <9QtWX-1qg-15@gated-at.bofh.it>
     [not found]       ` <9Qugj-1PK-1@gated-at.bofh.it>
2008-01-28  9:44         ` [PATCH] [8/18] BKL-removal: Remove BKL from remote_llseek 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=200801280917.52574.ak@suse.de \
    --to=ak@suse.de \
    --cc=Trond.Myklebust@netapp.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sfrench@samba.org \
    --cc=smfrench@gmail.com \
    --cc=swhiteho@redhat.com \
    --cc=vandrove@vc.cvut.cz \
    --subject='Re: [PATCH] [8/18] BKL-removal: Remove BKL from remote_llseek' \
    /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

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).