linux-kernel - [PATCH 3/3] kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create

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Date:	Thu, 15 Oct 2009 00:26:07 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Chris Mason <chris.mason@...cle.com>,
	Roland Dreier <rdreier@...co.com>, Ingo Molnar <mingo@...e.hu>,
	Andi Kleen <andi@...stfloor.org>,
	Jeff Mahoney <jeffm@...e.com>,
	Alexander Beregalov <a.beregalov@...il.com>,
	Bron Gondwana <brong@...tmail.fm>,
	Reiserfs <reiserfs-devel@...r.kernel.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	Andrea Gelmini <andrea.gelmini@...il.com>,
	"Trenton D. Adams" <trenton.d.adams@...il.com>,
	Thomas Meyer <thomas@...3r.de>,
	Alessio Igor Bogani <abogani@...ware.it>,
	Marcel Hilzinger <mhilzinger@...uxnewmedia.de>,
	Edward Shishkin <edward.shishkin@...il.com>,
	Laurent Riffard <laurent.riffard@...e.fr>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 3/3] kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create_0()

We had a watchdog in _get_block_create_0() that jumped to a fixup retry
path in case the bkl got relaxed while calling kmap().
This is not necessary anymore since we now have a reiserfs lock that is
not implicitly relaxed while sleeping.

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Cc: Jeff Mahoney <jeffm@...e.com>
Cc: Chris Mason <chris.mason@...cle.com>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Alexander Beregalov <a.beregalov@...il.com>
Cc: Laurent Riffard <laurent.riffard@...e.fr>
Cc: Thomas Gleixner <tglx@...utronix.de>
---
 fs/reiserfs/inode.c |   11 ++---------
 1 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 965c8ea..0d493a3 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -251,7 +251,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
 	struct cpu_key key;
 	struct buffer_head *bh;
 	struct item_head *ih, tmp_ih;
-	int fs_gen;
 	b_blocknr_t blocknr;
 	char *p = NULL;
 	int chars;
@@ -265,7 +264,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
 		     (loff_t) block * inode->i_sb->s_blocksize + 1, TYPE_ANY,
 		     3);
 
-      research:
 	result = search_for_position_by_key(inode->i_sb, &key, &path);
 	if (result != POSITION_FOUND) {
 		pathrelse(&path);
@@ -340,7 +338,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
 	}
 	// read file tail into part of page
 	offset = (cpu_key_k_offset(&key) - 1) & (PAGE_CACHE_SIZE - 1);
-	fs_gen = get_generation(inode->i_sb);
 	copy_item_head(&tmp_ih, ih);
 
 	/* we only want to kmap if we are reading the tail into the page.
@@ -348,13 +345,9 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
 	 ** sure we need to.  But, this means the item might move if
 	 ** kmap schedules
 	 */
-	if (!p) {
+	if (!p)
 		p = (char *)kmap(bh_result->b_page);
-		if (fs_changed(fs_gen, inode->i_sb)
-		    && item_moved(&tmp_ih, &path)) {
-			goto research;
-		}
-	}
+
 	p += offset;
 	memset(p, 0, inode->i_sb->s_blocksize);
 	do {
-- 
1.6.2.3

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