summaryrefslogtreecommitdiff
path: root/drivers/block/aoe/aoedev.c
blob: 240abaec159b708d90065f7643bb6b8fb2697fac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* Copyright (c) 2004 Coraid, Inc.  See COPYING for GPL terms. */
/*
 * aoedev.c
 * AoE device utility functions; maintains device list.
 */

#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/netdevice.h>
#include "aoe.h"

static struct aoedev *devlist;
static spinlock_t devlist_lock;

struct aoedev *
aoedev_bymac(unsigned char *macaddr)
{
	struct aoedev *d;
	ulong flags;

	spin_lock_irqsave(&devlist_lock, flags);

	for (d=devlist; d; d=d->next)
		if (!memcmp(d->addr, macaddr, 6))
			break;

	spin_unlock_irqrestore(&devlist_lock, flags);
	return d;
}

/* called with devlist lock held */
static struct aoedev *
aoedev_newdev(ulong nframes)
{
	struct aoedev *d;
	struct frame *f, *e;

	d = kcalloc(1, sizeof *d, GFP_ATOMIC);
	if (d == NULL)
		return NULL;
	f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
	if (f == NULL) {
		kfree(d);
		return NULL;
	}

	d->nframes = nframes;
	d->frames = f;
	e = f + nframes;
	for (; f<e; f++)
		f->tag = FREETAG;

	spin_lock_init(&d->lock);
	init_timer(&d->timer);
	d->bufpool = NULL;	/* defer to aoeblk_gdalloc */
	INIT_LIST_HEAD(&d->bufq);
	d->next = devlist;
	devlist = d;

	return d;
}

void
aoedev_downdev(struct aoedev *d)
{
	struct frame *f, *e;
	struct buf *buf;
	struct bio *bio;

	d->flags |= DEVFL_TKILL;
	del_timer(&d->timer);

	f = d->frames;
	e = f + d->nframes;
	for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
		if (f->tag == FREETAG || f->buf == NULL)
			continue;
		buf = f->buf;
		bio = buf->bio;
		if (--buf->nframesout == 0) {
			mempool_free(buf, d->bufpool);
			bio_endio(bio, bio->bi_size, -EIO);
		}
	}
	d->inprocess = NULL;

	while (!list_empty(&d->bufq)) {
		buf = container_of(d->bufq.next, struct buf, bufs);
		list_del(d->bufq.next);
		bio = buf->bio;
		mempool_free(buf, d->bufpool);
		bio_endio(bio, bio->bi_size, -EIO);
	}

	if (d->nopen)
		d->flags |= DEVFL_CLOSEWAIT;
	if (d->gd)
		d->gd->capacity = 0;

	d->flags &= ~DEVFL_UP;
}

struct aoedev *
aoedev_set(ulong sysminor, unsigned char *addr, struct net_device *ifp, ulong bufcnt)
{
	struct aoedev *d;
	ulong flags;

	spin_lock_irqsave(&devlist_lock, flags);

	for (d=devlist; d; d=d->next)
		if (d->sysminor == sysminor
		|| memcmp(d->addr, addr, sizeof d->addr) == 0)
			break;

	if (d == NULL && (d = aoedev_newdev(bufcnt)) == NULL) {
		spin_unlock_irqrestore(&devlist_lock, flags);
		printk(KERN_INFO "aoe: aoedev_set: aoedev_newdev failure.\n");
		return NULL;
	}

	spin_unlock_irqrestore(&devlist_lock, flags);
	spin_lock_irqsave(&d->lock, flags);

	d->ifp = ifp;

	if (d->sysminor != sysminor
	|| memcmp(d->addr, addr, sizeof d->addr)
	|| (d->flags & DEVFL_UP) == 0) {
		aoedev_downdev(d); /* flushes outstanding frames */
		memcpy(d->addr, addr, sizeof d->addr);
		d->sysminor = sysminor;
		d->aoemajor = AOEMAJOR(sysminor);
		d->aoeminor = AOEMINOR(sysminor);
	}

	spin_unlock_irqrestore(&d->lock, flags);
	return d;
}

static void
aoedev_freedev(struct aoedev *d)
{
	if (d->gd) {
		aoedisk_rm_sysfs(d);
		del_gendisk(d->gd);
		put_disk(d->gd);
	}
	kfree(d->frames);
	mempool_destroy(d->bufpool);
	kfree(d);
}

void
aoedev_exit(void)
{
	struct aoedev *d;
	ulong flags;

	flush_scheduled_work();

	while ((d = devlist)) {
		devlist = d->next;

		spin_lock_irqsave(&d->lock, flags);
		aoedev_downdev(d);
		spin_unlock_irqrestore(&d->lock, flags);

		del_timer_sync(&d->timer);
		aoedev_freedev(d);
	}
}

int __init
aoedev_init(void)
{
	spin_lock_init(&devlist_lock);
	return 0;
}