drivers/block/aoe/aoedev.c

   1 /* Copyright (c) 2006 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 "aoe.h"
  11
  12 static struct aoedev *devlist;
  13 static spinlock_t devlist_lock;
  14
  15 int
  16 aoedev_isbusy(struct aoedev *d)
  17 {
  18         struct frame *f, *e;
  19
  20         f = d->frames;
  21         e = f + d->nframes;
  22         do {
  23                 if (f->tag != FREETAG)
  24                         return 1;
  25         } while (++f < e);
  26
  27         return 0;
  28 }
  29
  30 struct aoedev *
  31 aoedev_by_aoeaddr(int maj, int min)
  32 {
  33         struct aoedev *d;
  34         ulong flags;
  35
  36         spin_lock_irqsave(&devlist_lock, flags);
  37
  38         for (d=devlist; d; d=d->next)
  39                 if (d->aoemajor == maj && d->aoeminor == min)
  40                         break;
  41
  42         spin_unlock_irqrestore(&devlist_lock, flags);
  43         return d;
  44 }
  45
  46 static void
  47 dummy_timer(ulong vp)
  48 {
  49         struct aoedev *d;
  50
  51         d = (struct aoedev *)vp;
  52         if (d->flags & DEVFL_TKILL)
  53                 return;
  54         d->timer.expires = jiffies + HZ;
  55         add_timer(&d->timer);
  56 }
  57
  58 /* called with devlist lock held */
  59 static struct aoedev *
  60 aoedev_newdev(ulong nframes)
  61 {
  62         struct aoedev *d;
  63         struct frame *f, *e;
  64
  65         d = kzalloc(sizeof *d, GFP_ATOMIC);
  66         f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
  67         switch (!d || !f) {
  68         case 0:
  69                 d->nframes = nframes;
  70                 d->frames = f;
  71                 e = f + nframes;
  72                 for (; f<e; f++) {
  73                         f->tag = FREETAG;
  74                         f->skb = new_skb(ETH_ZLEN);
  75                         if (!f->skb)
  76                                 break;
  77                 }
  78                 if (f == e)
  79                         break;
  80                 while (f > d->frames) {
  81                         f--;
  82                         dev_kfree_skb(f->skb);
  83                 }
  84         default:
  85                 if (f)
  86                         kfree(f);
  87                 if (d)
  88                         kfree(d);
  89                 return NULL;
  90         }
  91         INIT_WORK(&d->work, aoecmd_sleepwork);
  92         spin_lock_init(&d->lock);
  93         init_timer(&d->timer);
  94         d->timer.data = (ulong) d;
  95         d->timer.function = dummy_timer;
  96         d->timer.expires = jiffies + HZ;
  97         add_timer(&d->timer);
  98         d->bufpool = NULL;      /* defer to aoeblk_gdalloc */
  99         INIT_LIST_HEAD(&d->bufq);
 100         d->next = devlist;
 101         devlist = d;
 102
 103         return d;
 104 }
 105
 106 void
 107 aoedev_downdev(struct aoedev *d)
 108 {
 109         struct frame *f, *e;
 110         struct buf *buf;
 111         struct bio *bio;
 112
 113         f = d->frames;
 114         e = f + d->nframes;
 115         for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
 116                 if (f->tag == FREETAG || f->buf == NULL)
 117                         continue;
 118                 buf = f->buf;
 119                 bio = buf->bio;
 120                 if (--buf->nframesout == 0) {
 121                         mempool_free(buf, d->bufpool);
 122                         bio_endio(bio, -EIO);
 123                 }
 124                 skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;
 125         }
 126         d->inprocess = NULL;
 127
 128         while (!list_empty(&d->bufq)) {
 129                 buf = container_of(d->bufq.next, struct buf, bufs);
 130                 list_del(d->bufq.next);
 131                 bio = buf->bio;
 132                 mempool_free(buf, d->bufpool);
 133                 bio_endio(bio, -EIO);
 134         }
 135
 136         if (d->gd)
 137                 d->gd->capacity = 0;
 138
 139         d->flags &= ~(DEVFL_UP | DEVFL_PAUSE);
 140 }
 141
 142 /* find it or malloc it */
 143 struct aoedev *
 144 aoedev_by_sysminor_m(ulong sysminor, ulong bufcnt)
 145 {
 146         struct aoedev *d;
 147         ulong flags;
 148
 149         spin_lock_irqsave(&devlist_lock, flags);
 150
 151         for (d=devlist; d; d=d->next)
 152                 if (d->sysminor == sysminor)
 153                         break;
 154
 155         if (d == NULL) {
 156                 d = aoedev_newdev(bufcnt);
 157                 if (d == NULL) {
 158                         spin_unlock_irqrestore(&devlist_lock, flags);
 159                         printk(KERN_INFO "aoe: aoedev_newdev failure.\n");
 160                         return NULL;
 161                 }
 162                 d->sysminor = sysminor;
 163                 d->aoemajor = AOEMAJOR(sysminor);
 164                 d->aoeminor = AOEMINOR(sysminor);
 165         }
 166
 167         spin_unlock_irqrestore(&devlist_lock, flags);
 168         return d;
 169 }
 170
 171 static void
 172 aoedev_freedev(struct aoedev *d)
 173 {
 174         struct frame *f, *e;
 175
 176         if (d->gd) {
 177                 aoedisk_rm_sysfs(d);
 178                 del_gendisk(d->gd);
 179                 put_disk(d->gd);
 180         }
 181         f = d->frames;
 182         e = f + d->nframes;
 183         for (; f<e; f++) {
 184                 skb_shinfo(f->skb)->nr_frags = 0;
 185                 dev_kfree_skb(f->skb);
 186         }
 187         kfree(d->frames);
 188         if (d->bufpool)
 189                 mempool_destroy(d->bufpool);
 190         kfree(d);
 191 }
 192
 193 void
 194 aoedev_exit(void)
 195 {
 196         struct aoedev *d;
 197         ulong flags;
 198
 199         flush_scheduled_work();
 200
 201         while ((d = devlist)) {
 202                 devlist = d->next;
 203
 204                 spin_lock_irqsave(&d->lock, flags);
 205                 aoedev_downdev(d);
 206                 d->flags |= DEVFL_TKILL;
 207                 spin_unlock_irqrestore(&d->lock, flags);
 208
 209                 del_timer_sync(&d->timer);
 210                 aoedev_freedev(d);
 211         }
 212 }
 213
 214 int __init
 215 aoedev_init(void)
 216 {
 217         spin_lock_init(&devlist_lock);
 218         return 0;
 219 }
 220