Commit 54e37e09 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] dm: Maintain ordering when deferring bios

From: Joe Thornber <thornber@redhat.com>

Make sure that we maintain ordering when deferring bios.
parent a0befbbc
/*
* Copyright (C) 2004 Red Hat UK Ltd.
*
* This file is released under the GPL.
*/
#ifndef DM_BIO_LIST_H
#define DM_BIO_LIST_H
#include <linux/bio.h>
struct bio_list {
struct bio *head;
struct bio *tail;
};
static inline void bio_list_init(struct bio_list *bl)
{
bl->head = bl->tail = NULL;
}
static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
{
bio->bi_next = NULL;
if (bl->tail)
bl->tail->bi_next = bio;
else
bl->head = bio;
bl->tail = bio;
}
static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
{
if (bl->tail)
bl->tail->bi_next = bl2->head;
else
bl->head = bl2->head;
bl->tail = bl2->tail;
}
static inline struct bio *bio_list_pop(struct bio_list *bl)
{
struct bio *bio = bl->head;
if (bio) {
bl->head = bl->head->bi_next;
if (!bl->head)
bl->tail = NULL;
bio->bi_next = NULL;
}
return bio;
}
static inline struct bio *bio_list_get(struct bio_list *bl)
{
struct bio *bio = bl->head;
bl->head = bl->tail = NULL;
return bio;
}
#endif
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
*/ */
#include "dm.h" #include "dm.h"
#include "dm-bio-list.h"
#include <linux/init.h> #include <linux/init.h>
#include <linux/module.h> #include <linux/module.h>
...@@ -47,7 +48,7 @@ struct mapped_device { ...@@ -47,7 +48,7 @@ struct mapped_device {
*/ */
atomic_t pending; atomic_t pending;
wait_queue_head_t wait; wait_queue_head_t wait;
struct bio *deferred; struct bio_list deferred;
/* /*
* The current mapping. * The current mapping.
...@@ -195,8 +196,7 @@ static int queue_io(struct mapped_device *md, struct bio *bio) ...@@ -195,8 +196,7 @@ static int queue_io(struct mapped_device *md, struct bio *bio)
return 1; return 1;
} }
bio->bi_next = md->deferred; bio_list_add(&md->deferred, bio);
md->deferred = bio;
up_write(&md->lock); up_write(&md->lock);
return 0; /* deferred successfully */ return 0; /* deferred successfully */
...@@ -822,8 +822,7 @@ int dm_resume(struct mapped_device *md) ...@@ -822,8 +822,7 @@ int dm_resume(struct mapped_device *md)
dm_table_resume_targets(md->map); dm_table_resume_targets(md->map);
clear_bit(DMF_SUSPENDED, &md->flags); clear_bit(DMF_SUSPENDED, &md->flags);
clear_bit(DMF_BLOCK_IO, &md->flags); clear_bit(DMF_BLOCK_IO, &md->flags);
def = md->deferred; def = bio_list_get(&md->deferred);
md->deferred = NULL;
up_write(&md->lock); up_write(&md->lock);
flush_deferred_io(def); flush_deferred_io(def);
......
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