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From: Nick Piggin <npiggin@suse.de>
To: Andrew Morton <akpm@osdl.org>
Cc: Hugh Dickins <hugh@veritas.com>,
	Linux Memory Management <linux-mm@kvack.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Nick Piggin <npiggin@suse.de>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Subject: [patch 2/3] fs: buffer don't PageUptodate without page locked
Date: Thu,  8 Feb 2007 14:27:20 +0100 (CET)	[thread overview]
Message-ID: <20070208111443.30513.47430.sendpatchset@linux.site> (raw)
In-Reply-To: <20070208111421.30513.77904.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>

 fs/buffer.c |   11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -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.

WARNING: multiple messages have this Message-ID (diff)
From: Nick Piggin <npiggin@suse.de>
To: Andrew Morton <akpm@osdl.org>
Cc: Hugh Dickins <hugh@veritas.com>,
	Linux Memory Management <linux-mm@kvack.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Nick Piggin <npiggin@suse.de>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Subject: [patch 2/3] fs: buffer don't PageUptodate without page locked
Date: Thu,  8 Feb 2007 14:27:20 +0100 (CET)	[thread overview]
Message-ID: <20070208111443.30513.47430.sendpatchset@linux.site> (raw)
In-Reply-To: <20070208111421.30513.77904.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>

 fs/buffer.c |   11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -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.

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  parent reply	other threads:[~2007-02-08 13:27 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-08 13:26 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem (try 2) Nick Piggin
2007-02-08 13:26 ` Nick Piggin
2007-02-08 13:27 ` [patch 1/3] mm: fix PageUptodate memorder Nick Piggin
2007-02-08 13:27   ` Nick Piggin
2007-02-08 13:27 ` Nick Piggin [this message]
2007-02-08 13:27   ` [patch 2/3] fs: buffer don't PageUptodate without page locked Nick Piggin
2007-02-08 13:27 ` [patch 3/3] mm: make read_cache_page synchronous Nick Piggin
2007-02-08 13:27   ` Nick Piggin
2007-02-08 22:21 ` [patch 0/3] 2.6.20 fix for PageUptodate memorder problem (try 2) Benjamin Herrenschmidt
2007-02-08 22:21   ` Benjamin Herrenschmidt
2007-02-09  0:41 ` Hugh Dickins
2007-02-09  0:41   ` Hugh Dickins
2007-02-09  1:31   ` Nick Piggin
2007-02-09  1:31     ` Nick Piggin
2007-02-09  1:44     ` Benjamin Herrenschmidt
2007-02-09  1:44       ` Benjamin Herrenschmidt
2007-02-09  1:41   ` Benjamin Herrenschmidt
2007-02-09  1:41     ` Benjamin Herrenschmidt
  -- strict thread matches above, loose matches on Subject: below --
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
2007-02-15  7:31   ` 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
2007-02-10  2:31   ` Nick Piggin
2007-02-06  8:02 [patch 0/3] 2.6.20 fix for PageUptodate memorder problem Nick Piggin
2007-02-06  8:02 ` [patch 2/3] fs: buffer don't PageUptodate without page locked Nick Piggin
2007-02-06  8:02   ` Nick Piggin
2007-02-06  8:21   ` Andrew Morton
2007-02-06  8:21     ` Andrew Morton
2007-02-06  8:31     ` Nick Piggin
2007-02-06  8:31       ` Nick Piggin

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