aoedev.c (fea05a26c3a215796b7a4fa5cbc25278d3e16d30) aoedev.c (0c966214589b9767fd8771b71328f83bac58cb25)
1/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
2/*
3 * aoedev.c
4 * AoE device utility functions; maintains device list.
5 */
6
7#include <linux/hdreg.h>
8#include <linux/blkdev.h>
9#include <linux/netdevice.h>
10#include <linux/delay.h>
11#include <linux/slab.h>
1/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
2/*
3 * aoedev.c
4 * AoE device utility functions; maintains device list.
5 */
6
7#include <linux/hdreg.h>
8#include <linux/blkdev.h>
9#include <linux/netdevice.h>
10#include <linux/delay.h>
11#include <linux/slab.h>
12#include <linux/bitmap.h>
13#include <linux/kdev_t.h>
12#include "aoe.h"
13
14static void dummy_timer(ulong);
15static void aoedev_freedev(struct aoedev *);
16static void freetgt(struct aoedev *d, struct aoetgt *t);
17static void skbpoolfree(struct aoedev *d);
18
19static struct aoedev *devlist;
20static DEFINE_SPINLOCK(devlist_lock);
21
14#include "aoe.h"
15
16static void dummy_timer(ulong);
17static void aoedev_freedev(struct aoedev *);
18static void freetgt(struct aoedev *d, struct aoetgt *t);
19static void skbpoolfree(struct aoedev *d);
20
21static struct aoedev *devlist;
22static DEFINE_SPINLOCK(devlist_lock);
23
22/*
23 * Users who grab a pointer to the device with aoedev_by_aoeaddr or
24 * aoedev_by_sysminor_m automatically get a reference count and must
25 * be responsible for performing a aoedev_put. With the addition of
26 * async kthread processing I'm no longer confident that we can
27 * guarantee consistency in the face of device flushes.
28 *
29 * For the time being, we only bother to add extra references for
30 * frames sitting on the iocq. When the kthreads finish processing
31 * these frames, they will aoedev_put the device.
24/* Because some systems will have one, many, or no
25 * - partitions,
26 * - slots per shelf,
27 * - or shelves,
28 * we need some flexibility in the way the minor numbers
29 * are allocated. So they are dynamic.
32 */
30 */
33struct aoedev *
34aoedev_by_aoeaddr(int maj, int min)
31#define N_DEVS ((1U<<MINORBITS)/AOE_PARTITIONS)
32
33static DEFINE_SPINLOCK(used_minors_lock);
34static DECLARE_BITMAP(used_minors, N_DEVS);
35
36static int
37minor_get(ulong *minor)
35{
38{
36 struct aoedev *d;
37 ulong flags;
39 ulong flags;
40 ulong n;
41 int error = 0;
38
42
39 spin_lock_irqsave(&devlist_lock, flags);
43 spin_lock_irqsave(&used_minors_lock, flags);
44 n = find_first_zero_bit(used_minors, N_DEVS);
45 if (n < N_DEVS)
46 set_bit(n, used_minors);
47 else
48 error = -1;
49 spin_unlock_irqrestore(&used_minors_lock, flags);
40
50
41 for (d=devlist; d; d=d->next)
42 if (d->aoemajor == maj && d->aoeminor == min) {
43 d->ref++;
44 break;
45 }
51 *minor = n * AOE_PARTITIONS;
52 return error;
53}
46
54
47 spin_unlock_irqrestore(&devlist_lock, flags);
48 return d;
55static void
56minor_free(ulong minor)
57{
58 ulong flags;
59
60 minor /= AOE_PARTITIONS;
61 BUG_ON(minor >= N_DEVS);
62
63 spin_lock_irqsave(&used_minors_lock, flags);
64 BUG_ON(!test_bit(minor, used_minors));
65 clear_bit(minor, used_minors);
66 spin_unlock_irqrestore(&used_minors_lock, flags);
49}
50
67}
68
69/*
70 * Users who grab a pointer to the device with aoedev_by_aoeaddr
71 * automatically get a reference count and must be responsible
72 * for performing a aoedev_put. With the addition of async
73 * kthread processing I'm no longer confident that we can
74 * guarantee consistency in the face of device flushes.
75 *
76 * For the time being, we only bother to add extra references for
77 * frames sitting on the iocq. When the kthreads finish processing
78 * these frames, they will aoedev_put the device.
79 */
80
51void
52aoedev_put(struct aoedev *d)
53{
54 ulong flags;
55
56 spin_lock_irqsave(&devlist_lock, flags);
57 d->ref--;
58 spin_unlock_irqrestore(&devlist_lock, flags);

--- 95 unchanged lines hidden (view full) ---

154 }
155 t = d->targets;
156 e = t + NTARGETS;
157 for (; t < e && *t; t++)
158 freetgt(d, *t);
159 if (d->bufpool)
160 mempool_destroy(d->bufpool);
161 skbpoolfree(d);
81void
82aoedev_put(struct aoedev *d)
83{
84 ulong flags;
85
86 spin_lock_irqsave(&devlist_lock, flags);
87 d->ref--;
88 spin_unlock_irqrestore(&devlist_lock, flags);

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184 }
185 t = d->targets;
186 e = t + NTARGETS;
187 for (; t < e && *t; t++)
188 freetgt(d, *t);
189 if (d->bufpool)
190 mempool_destroy(d->bufpool);
191 skbpoolfree(d);
192 minor_free(d->sysminor);
162 kfree(d);
163}
164
165int
166aoedev_flush(const char __user *str, size_t cnt)
167{
168 ulong flags;
169 struct aoedev *d, **dd;

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241 struct sk_buff *skb, *tmp;
242
243 skb_queue_walk_safe(&d->skbpool, skb, tmp)
244 skbfree(skb);
245
246 __skb_queue_head_init(&d->skbpool);
247}
248
193 kfree(d);
194}
195
196int
197aoedev_flush(const char __user *str, size_t cnt)
198{
199 ulong flags;
200 struct aoedev *d, **dd;

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272 struct sk_buff *skb, *tmp;
273
274 skb_queue_walk_safe(&d->skbpool, skb, tmp)
275 skbfree(skb);
276
277 __skb_queue_head_init(&d->skbpool);
278}
279
249/* find it or malloc it */
280/* find it or allocate it */
250struct aoedev *
281struct aoedev *
251aoedev_by_sysminor_m(ulong sysminor)
282aoedev_by_aoeaddr(ulong maj, int min, int do_alloc)
252{
253 struct aoedev *d;
254 int i;
255 ulong flags;
283{
284 struct aoedev *d;
285 int i;
286 ulong flags;
287 ulong sysminor;
256
257 spin_lock_irqsave(&devlist_lock, flags);
258
259 for (d=devlist; d; d=d->next)
288
289 spin_lock_irqsave(&devlist_lock, flags);
290
291 for (d=devlist; d; d=d->next)
260 if (d->sysminor == sysminor) {
292 if (d->aoemajor == maj && d->aoeminor == min) {
261 d->ref++;
262 break;
263 }
293 d->ref++;
294 break;
295 }
264 if (d)
296 if (d || !do_alloc || minor_get(&sysminor) < 0)
265 goto out;
266 d = kcalloc(1, sizeof *d, GFP_ATOMIC);
267 if (!d)
268 goto out;
269 INIT_WORK(&d->work, aoecmd_sleepwork);
270 spin_lock_init(&d->lock);
271 skb_queue_head_init(&d->skbpool);
272 init_timer(&d->timer);
273 d->timer.data = (ulong) d;
274 d->timer.function = dummy_timer;
275 d->timer.expires = jiffies + HZ;
276 add_timer(&d->timer);
277 d->bufpool = NULL; /* defer to aoeblk_gdalloc */
278 d->tgt = d->targets;
279 d->ref = 1;
280 for (i = 0; i < NFACTIVE; i++)
281 INIT_LIST_HEAD(&d->factive[i]);
282 d->sysminor = sysminor;
297 goto out;
298 d = kcalloc(1, sizeof *d, GFP_ATOMIC);
299 if (!d)
300 goto out;
301 INIT_WORK(&d->work, aoecmd_sleepwork);
302 spin_lock_init(&d->lock);
303 skb_queue_head_init(&d->skbpool);
304 init_timer(&d->timer);
305 d->timer.data = (ulong) d;
306 d->timer.function = dummy_timer;
307 d->timer.expires = jiffies + HZ;
308 add_timer(&d->timer);
309 d->bufpool = NULL; /* defer to aoeblk_gdalloc */
310 d->tgt = d->targets;
311 d->ref = 1;
312 for (i = 0; i < NFACTIVE; i++)
313 INIT_LIST_HEAD(&d->factive[i]);
314 d->sysminor = sysminor;
283 d->aoemajor = AOEMAJOR(sysminor);
284 d->aoeminor = AOEMINOR(sysminor);
315 d->aoemajor = maj;
316 d->aoeminor = min;
285 d->mintimer = MINTIMER;
286 d->next = devlist;
287 devlist = d;
288 out:
289 spin_unlock_irqrestore(&devlist_lock, flags);
290 return d;
291}
292

--- 48 unchanged lines hidden --- 		317 d->mintimer = MINTIMER;
318 d->next = devlist;
319 devlist = d;
320 out:
321 spin_unlock_irqrestore(&devlist_lock, flags);
322 return d;
323}
324

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