summaryrefslogtreecommitdiff
path: root/drivers/block/aoe/aoedev.c
blob: 7fd63d4daf517d866bf9d83e97f36dc21c6d6bcf (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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/* Copyright (c) 2006 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;

int
aoedev_isbusy(struct aoedev *d)
{
	struct frame *f, *e;

	f = d->frames;
	e = f + d->nframes;
	do {
		if (f->tag != FREETAG)
			return 1;
	} while (++f < e);

	return 0;
}

struct aoedev *
aoedev_by_aoeaddr(int maj, int min)
{
	struct aoedev *d;
	ulong flags;

	spin_lock_irqsave(&devlist_lock, flags);

	for (d=devlist; d; d=d->next)
		if (d->aoemajor == maj && d->aoeminor == min)
			break;

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

static void
dummy_timer(ulong vp)
{
	struct aoedev *d;

	d = (struct aoedev *)vp;
	if (d->flags & DEVFL_TKILL)
		return;
	d->timer.expires = jiffies + HZ;
	add_timer(&d->timer);
}

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

	d = kzalloc(sizeof *d, GFP_ATOMIC);
	f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
 	switch (!d || !f) {
 	case 0:
 		d->nframes = nframes;
 		d->frames = f;
 		e = f + nframes;
 		for (; f<e; f++) {
 			f->tag = FREETAG;
 			f->skb = new_skb(ETH_ZLEN);
 			if (!f->skb)
 				break;
 		}
 		if (f == e)
 			break;
 		while (f > d->frames) {
 			f--;
 			dev_kfree_skb(f->skb);
 		}
 	default:
 		if (f)
 			kfree(f);
 		if (d)
 			kfree(d);
		return NULL;
	}
	INIT_WORK(&d->work, aoecmd_sleepwork, d);
	spin_lock_init(&d->lock);
	init_timer(&d->timer);
	d->timer.data = (ulong) d;
	d->timer.function = dummy_timer;
	d->timer.expires = jiffies + HZ;
	add_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;

	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);
		}
		skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;
	}
	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->gd)
		d->gd->capacity = 0;

	d->flags &= ~(DEVFL_UP | DEVFL_PAUSE);
}

/* find it or malloc it */
struct aoedev *
aoedev_by_sysminor_m(ulong sysminor, ulong bufcnt)
{
	struct aoedev *d;
	ulong flags;

	spin_lock_irqsave(&devlist_lock, flags);

	for (d=devlist; d; d=d->next)
		if (d->sysminor == sysminor)
			break;

	if (d == NULL) {
		d = aoedev_newdev(bufcnt);
	 	if (d == NULL) {
			spin_unlock_irqrestore(&devlist_lock, flags);
			iprintk("aoedev_newdev failure.\n");
			return NULL;
		}
		d->sysminor = sysminor;
		d->aoemajor = AOEMAJOR(sysminor);
		d->aoeminor = AOEMINOR(sysminor);
	}

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

static void
aoedev_freedev(struct aoedev *d)
{
	struct frame *f, *e;

	if (d->gd) {
		aoedisk_rm_sysfs(d);
		del_gendisk(d->gd);
		put_disk(d->gd);
	}
	f = d->frames;
	e = f + d->nframes;
	for (; f<e; f++) {
		skb_shinfo(f->skb)->nr_frags = 0;
		dev_kfree_skb(f->skb);
	}
	kfree(d->frames);
	if (d->bufpool)
		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);
		d->flags |= DEVFL_TKILL;
		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;
}