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
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
doorbell.h
/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef MLX4_DOORBELL_H
#define MLX4_DOORBELL_H

#include <linux/types.h>
#include <linux/io.h>

#define MLX4_SEND_DOORBELL    0x14
#define MLX4_CQ_DOORBELL      0x20

#if BITS_PER_LONG == 64
/*
 * Assume that we can just write a 64-bit doorbell atomically.  s390
 * actually doesn't have writeq() but S/390 systems don't even have
 * PCI so we won't worry about it.
 */

#define MLX4_DECLARE_DOORBELL_LOCK(name)
#define MLX4_INIT_DOORBELL_LOCK(ptr)    do { } while (0)
#define MLX4_GET_DOORBELL_LOCK(ptr)      (NULL)

static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
				spinlock_t *doorbell_lock)
{
	__raw_writeq(*(u64 *) val, dest);
}

#else

/*
 * Just fall back to a spinlock to protect the doorbell if
 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
 * MMIO writes.
 */

#define MLX4_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
#define MLX4_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
#define MLX4_GET_DOORBELL_LOCK(ptr)      (ptr)

static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
				spinlock_t *doorbell_lock)
{
	unsigned long flags;

	spin_lock_irqsave(doorbell_lock, flags);
	__raw_writel((__force u32) val[0], dest);
	__raw_writel((__force u32) val[1], dest + 4);
	spin_unlock_irqrestore(doorbell_lock, flags);
}

#endif

#endif /* MLX4_DOORBELL_H */
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