1 /* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
4 * AoE device utility functions; maintains device list.
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>
14 #include <linux/moduleparam.h>
17 static void dummy_timer(ulong);
18 static void freetgt(struct aoedev *d, struct aoetgt *t);
19 static void skbpoolfree(struct aoedev *d);
21 static int aoe_dyndevs = 1;
22 module_param(aoe_dyndevs, int, 0644);
23 MODULE_PARM_DESC(aoe_dyndevs, "Use dynamic minor numbers for devices.");
25 static struct aoedev *devlist;
26 static DEFINE_SPINLOCK(devlist_lock);
28 /* Because some systems will have one, many, or no
32 * we need some flexibility in the way the minor numbers
33 * are allocated. So they are dynamic.
35 #define N_DEVS ((1U<<MINORBITS)/AOE_PARTITIONS)
37 static DEFINE_SPINLOCK(used_minors_lock);
38 static DECLARE_BITMAP(used_minors, N_DEVS);
41 minor_get_dyn(ulong *sysminor)
47 spin_lock_irqsave(&used_minors_lock, flags);
48 n = find_first_zero_bit(used_minors, N_DEVS);
50 set_bit(n, used_minors);
53 spin_unlock_irqrestore(&used_minors_lock, flags);
55 *sysminor = n * AOE_PARTITIONS;
60 minor_get_static(ulong *sysminor, ulong aoemaj, int aoemin)
66 /* for backwards compatibility when !aoe_dyndevs,
67 * a static number of supported slots per shelf */
71 if (aoemin >= NPERSHELF) {
72 pr_err("aoe: %s %d slots per shelf\n",
73 "static minor device numbers support only",
79 n = aoemaj * NPERSHELF + aoemin;
81 pr_err("aoe: %s with e%ld.%d\n",
82 "cannot use static minor device numbers",
88 spin_lock_irqsave(&used_minors_lock, flags);
89 if (test_bit(n, used_minors)) {
90 pr_err("aoe: %s %lu\n",
91 "existing device already has static minor number",
95 set_bit(n, used_minors);
96 spin_unlock_irqrestore(&used_minors_lock, flags);
97 *sysminor = n * AOE_PARTITIONS;
103 minor_get(ulong *sysminor, ulong aoemaj, int aoemin)
106 return minor_get_dyn(sysminor);
108 return minor_get_static(sysminor, aoemaj, aoemin);
112 minor_free(ulong minor)
116 minor /= AOE_PARTITIONS;
117 BUG_ON(minor >= N_DEVS);
119 spin_lock_irqsave(&used_minors_lock, flags);
120 BUG_ON(!test_bit(minor, used_minors));
121 clear_bit(minor, used_minors);
122 spin_unlock_irqrestore(&used_minors_lock, flags);
126 * Users who grab a pointer to the device with aoedev_by_aoeaddr
127 * automatically get a reference count and must be responsible
128 * for performing a aoedev_put. With the addition of async
129 * kthread processing I'm no longer confident that we can
130 * guarantee consistency in the face of device flushes.
132 * For the time being, we only bother to add extra references for
133 * frames sitting on the iocq. When the kthreads finish processing
134 * these frames, they will aoedev_put the device.
138 aoedev_put(struct aoedev *d)
142 spin_lock_irqsave(&devlist_lock, flags);
144 spin_unlock_irqrestore(&devlist_lock, flags);
148 dummy_timer(ulong vp)
152 d = (struct aoedev *)vp;
153 if (d->flags & DEVFL_TKILL)
155 d->timer.expires = jiffies + HZ;
156 add_timer(&d->timer);
160 aoe_failip(struct aoedev *d)
166 aoe_failbuf(d, d->ip.buf);
171 while ((bio = d->ip.nxbio)) {
172 clear_bit(BIO_UPTODATE, &bio->bi_flags);
173 d->ip.nxbio = bio->bi_next;
174 n = (unsigned long) rq->special;
175 rq->special = (void *) --n;
177 if ((unsigned long) rq->special == 0)
178 aoe_end_request(d, rq, 0);
182 downdev_frame(struct list_head *pos)
186 f = list_entry(pos, struct frame, head);
189 f->buf->nframesout--;
190 aoe_failbuf(f->t->d, f->buf);
196 aoedev_downdev(struct aoedev *d)
198 struct aoetgt *t, **tt, **te;
199 struct list_head *head, *pos, *nx;
203 d->flags &= ~DEVFL_UP;
205 /* clean out active and to-be-retransmitted buffers */
206 for (i = 0; i < NFACTIVE; i++) {
207 head = &d->factive[i];
208 list_for_each_safe(pos, nx, head)
212 list_for_each_safe(pos, nx, head)
215 /* reset window dressings */
217 te = tt + d->ntargets;
218 for (; tt < te && (t = *tt); tt++) {
223 /* clean out the in-process request (if any) */
226 /* fast fail all pending I/O */
228 while ((rq = blk_peek_request(d->blkq))) {
229 blk_start_request(rq);
230 aoe_end_request(d, rq, 1);
235 set_capacity(d->gd, 0);
238 /* return whether the user asked for this particular
239 * device to be flushed
242 user_req(char *s, size_t slen, struct aoedev *d)
249 p = strrchr(d->gd->disk_name, '/');
251 p = d->gd->disk_name;
254 lim = sizeof(d->gd->disk_name);
255 lim -= p - d->gd->disk_name;
259 return !strncmp(s, p, lim);
263 freedev(struct aoedev *d)
265 struct aoetgt **t, **e;
269 spin_lock_irqsave(&d->lock, flags);
270 if (d->flags & DEVFL_TKILL
271 && !(d->flags & DEVFL_FREEING)) {
272 d->flags |= DEVFL_FREEING;
275 spin_unlock_irqrestore(&d->lock, flags);
279 del_timer_sync(&d->timer);
284 blk_cleanup_queue(d->blkq);
288 for (; t < e && *t; t++)
291 mempool_destroy(d->bufpool);
293 minor_free(d->sysminor);
295 spin_lock_irqsave(&d->lock, flags);
296 d->flags |= DEVFL_FREED;
297 spin_unlock_irqrestore(&d->lock, flags);
306 flush(const char __user *str, size_t cnt, int exiting)
309 struct aoedev *d, **dd;
312 int specified = 0; /* flush a specific device */
313 unsigned int skipflags;
315 skipflags = DEVFL_GDALLOC | DEVFL_NEWSIZE | DEVFL_TKILL;
317 if (!exiting && cnt >= 3) {
318 if (cnt > sizeof buf)
320 if (copy_from_user(buf, str, cnt))
322 all = !strncmp(buf, "all", 3);
327 flush_scheduled_work();
328 /* pass one: without sleeping, do aoedev_downdev */
329 spin_lock_irqsave(&devlist_lock, flags);
330 for (d = devlist; d; d = d->next) {
333 /* unconditionally take each device down */
334 } else if (specified) {
335 if (!user_req(buf, cnt, d))
337 } else if ((!all && (d->flags & DEVFL_UP))
338 || d->flags & skipflags
344 d->flags |= DEVFL_TKILL;
346 spin_unlock(&d->lock);
348 spin_unlock_irqrestore(&devlist_lock, flags);
350 /* pass two: call freedev, which might sleep,
351 * for aoedevs marked with DEVFL_TKILL
354 spin_lock_irqsave(&devlist_lock, flags);
355 for (d = devlist; d; d = d->next) {
357 if (d->flags & DEVFL_TKILL
358 && !(d->flags & DEVFL_FREEING)) {
359 spin_unlock(&d->lock);
360 spin_unlock_irqrestore(&devlist_lock, flags);
364 spin_unlock(&d->lock);
367 /* pass three: remove aoedevs marked with DEVFL_FREED */
368 for (dd = &devlist, d = *dd; d; d = *dd) {
369 struct aoedev *doomed = NULL;
372 if (d->flags & DEVFL_FREED) {
378 spin_unlock(&d->lock);
380 kfree(doomed->targets);
383 spin_unlock_irqrestore(&devlist_lock, flags);
389 aoedev_flush(const char __user *str, size_t cnt)
391 return flush(str, cnt, NOT_EXITING);
394 /* This has been confirmed to occur once with Tms=3*1000 due to the
395 * driver changing link and not processing its transmit ring. The
396 * problem is hard enough to solve by returning an error that I'm
397 * still punting on "solving" this.
400 skbfree(struct sk_buff *skb)
402 enum { Sms = 250, Tms = 30 * 1000};
407 while (atomic_read(&skb_shinfo(skb)->dataref) != 1 && i-- > 0)
411 "aoe: %s holds ref: %s\n",
412 skb->dev ? skb->dev->name : "netif",
413 "cannot free skb -- memory leaked.");
416 skb->truesize -= skb->data_len;
417 skb_shinfo(skb)->nr_frags = skb->data_len = 0;
423 skbpoolfree(struct aoedev *d)
425 struct sk_buff *skb, *tmp;
427 skb_queue_walk_safe(&d->skbpool, skb, tmp)
430 __skb_queue_head_init(&d->skbpool);
433 /* find it or allocate it */
435 aoedev_by_aoeaddr(ulong maj, int min, int do_alloc)
442 spin_lock_irqsave(&devlist_lock, flags);
444 for (d=devlist; d; d=d->next)
445 if (d->aoemajor == maj && d->aoeminor == min) {
447 if (d->flags & DEVFL_TKILL) {
448 spin_unlock(&d->lock);
453 spin_unlock(&d->lock);
456 if (d || !do_alloc || minor_get(&sysminor, maj, min) < 0)
458 d = kcalloc(1, sizeof *d, GFP_ATOMIC);
461 d->targets = kcalloc(NTARGETS, sizeof(*d->targets), GFP_ATOMIC);
467 d->ntargets = NTARGETS;
468 INIT_WORK(&d->work, aoecmd_sleepwork);
469 spin_lock_init(&d->lock);
470 skb_queue_head_init(&d->skbpool);
471 init_timer(&d->timer);
472 d->timer.data = (ulong) d;
473 d->timer.function = dummy_timer;
474 d->timer.expires = jiffies + HZ;
475 add_timer(&d->timer);
476 d->bufpool = NULL; /* defer to aoeblk_gdalloc */
479 for (i = 0; i < NFACTIVE; i++)
480 INIT_LIST_HEAD(&d->factive[i]);
481 INIT_LIST_HEAD(&d->rexmitq);
482 d->sysminor = sysminor;
485 d->rttavg = RTTAVG_INIT;
486 d->rttdev = RTTDEV_INIT;
490 spin_unlock_irqrestore(&devlist_lock, flags);
495 freetgt(struct aoedev *d, struct aoetgt *t)
498 struct list_head *pos, *nx, *head;
501 for (ifp = t->ifs; ifp < &t->ifs[NAOEIFS]; ++ifp) {
508 list_for_each_safe(pos, nx, head) {
510 f = list_entry(pos, struct frame, head);
520 flush_scheduled_work();
522 flush(NULL, 0, EXITING);