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Revision 7bf811a595a895b7a886dcf218d0d34f97df76dc authored by Josef Bacik on 08 October 2013, 02:11:09 UTC, committed by Chris Mason on 11 October 2013, 01:27:56 UTC 
Btrfs: limit delalloc pages outside of find_delalloc_range
 
Liu fixed part of this problem and unfortunately I steered him in slightly the
wrong direction and so didn't completely fix the problem.  The problem is we
limit the size of the delalloc range we are looking for to max bytes and then we
try to lock that range.  If we fail to lock the pages in that range we will
shrink the max bytes to a single page and re loop.  However if our first page is
inside of the delalloc range then we will end up limiting the end of the range
to a period before our first page.  This is illustrated below

[0 -------- delalloc range --------- 256mb]
                                  [page]

So find_delalloc_range will return with delalloc_start as 0 and end as 128mb,
and then we will notice that delalloc_start < *start and adjust it up, but not
adjust delalloc_end up, so things go sideways.  To fix this we need to not limit
the max bytes in find_delalloc_range, but in find_lock_delalloc_range and that
way we don't end up with this confusion.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
1 parent 4871c15
Raw File
clkdev.h 
/*
 *  include/linux/clkdev.h
 *
 *  Copyright (C) 2008 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Helper for the clk API to assist looking up a struct clk.
 */
#ifndef __CLKDEV_H
#define __CLKDEV_H

#include <asm/clkdev.h>

struct clk;
struct device;

struct clk_lookup {
	struct list_head	node;
	const char		*dev_id;
	const char		*con_id;
	struct clk		*clk;
};

#define CLKDEV_INIT(d, n, c)	\
	{			\
		.dev_id = d,	\
		.con_id = n,	\
		.clk = c,	\
	}

struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
	const char *dev_fmt, ...);

void clkdev_add(struct clk_lookup *cl);
void clkdev_drop(struct clk_lookup *cl);

void clkdev_add_table(struct clk_lookup *, size_t);
int clk_add_alias(const char *, const char *, char *, struct device *);

int clk_register_clkdev(struct clk *, const char *, const char *, ...);
int clk_register_clkdevs(struct clk *, struct clk_lookup *, size_t);

#endif
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