LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Nick Piggin <npiggin@suse.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hugh@veritas.com>, Andrew Morton <akpm@osdl.org>,
	Nick Piggin <npiggin@suse.de>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Linux Memory Management <linux-mm@kvack.org>,
	Linux Filesystems <linux-fsdevel@vger.kernel.org>
Subject: [patch 2/3] fs: buffer don't PageUptodate without page locked
Date: Tue,  6 Feb 2007 09:02:23 +0100 (CET)	[thread overview]
Message-ID: <20070206054947.21042.32493.sendpatchset@linux.site> (raw)
In-Reply-To: <20070206054925.21042.50546.sendpatchset@linux.site>

__block_write_full_page is calling SetPageUptodate without the page locked.
This is unusual, but not incorrect, as PG_writeback is still set.

However with the previous patch, this is now a problem: so don't bother
setting the page uptodate in this case (it is weird that the write path
does such a thing anyway). Instead just leave it to the read side to bring
the page uptodate when it notices that all buffers are uptodate.

Signed-off-by: Nick Piggin <npiggin@suse.de>

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -1679,6 +1679,7 @@ static int __block_write_full_page(struc
 	 */
 	BUG_ON(PageWriteback(page));
 	set_page_writeback(page);
+	unlock_page(page);
 
 	do {
 		struct buffer_head *next = bh->b_this_page;
@@ -1688,7 +1689,6 @@ static int __block_write_full_page(struc
 		}
 		bh = next;
 	} while (bh != head);
-	unlock_page(page);
 
 	err = 0;
 done:
@@ -1698,17 +1698,8 @@ done:
 		 * clean.  Someone wrote them back by hand with
 		 * ll_rw_block/submit_bh.  A rare case.
 		 */
-		int uptodate = 1;
-		do {
-			if (!buffer_uptodate(bh)) {
-				uptodate = 0;
-				break;
-			}
-			bh = bh->b_this_page;
-		} while (bh != head);
-		if (uptodate)
-			SetPageUptodate(page);
 		end_page_writeback(page);
+
 		/*
 		 * The page and buffer_heads can be released at any time from
 		 * here on.

  parent reply	other threads:[~2007-02-06  8:02 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-06  8:02 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem Nick Piggin
2007-02-06  8:02 ` [patch 1/3] mm: fix PageUptodate memorder Nick Piggin
2007-02-06  8:25   ` Andrew Morton
2007-02-06  8:51     ` Nick Piggin
2007-02-06  8:02 ` Nick Piggin [this message]
2007-02-06  8:21   ` [patch 2/3] fs: buffer don't PageUptodate without page locked Andrew Morton
2007-02-06  8:31     ` Nick Piggin
2007-02-06  8:02 ` [patch 3/3] mm: make read_cache_page synchronous Nick Piggin
2007-02-06  8:28   ` Andrew Morton
2007-02-06  8:56     ` Nick Piggin
2007-02-06  8:58     ` Nick Piggin
2007-02-06 22:58 ` [patch 0/3] 2.6.20 fix for PageUptodate memorder problem David Chinner
2007-02-07  3:13   ` Nick Piggin
2007-02-08 13:26 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem (try 2) Nick Piggin
2007-02-08 13:27 ` [patch 2/3] fs: buffer don't PageUptodate without page locked Nick Piggin
2007-02-10  2:31 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem (try 3) Nick Piggin
2007-02-10  2:31 ` [patch 2/3] fs: buffer don't PageUptodate without page locked Nick Piggin
2007-02-15  7:31 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem (try 4) Nick Piggin
2007-02-15  7:31 ` [patch 2/3] fs: buffer don't PageUptodate without page locked Nick Piggin

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=20070206054947.21042.32493.sendpatchset@linux.site \
    --to=npiggin@suse.de \
    --cc=akpm@osdl.org \
    --cc=hugh@veritas.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=torvalds@linux-foundation.org \
    --subject='Re: [patch 2/3] fs: buffer don'\''t PageUptodate without page locked' \
    /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).