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         if (d == NULL)
  67                 return NULL;
  68         f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
  69         if (f == NULL) {
  70                 kfree(d);
  71                 return NULL;
  72         }
  73
  74         INIT_WORK(&d->work, aoecmd_sleepwork, d);
  75
  76         d->nframes = nframes;
  77         d->frames = f;
  78         e = f + nframes;
  79         for (; f<e; f++)
  80                 f->tag = FREETAG;
  81
  82         spin_lock_init(&d->lock);
  83         init_timer(&d->timer);
  84         d->timer.data = (ulong) d;
  85         d->timer.function = dummy_timer;
  86         d->timer.expires = jiffies + HZ;
  87         add_timer(&d->timer);
  88         d->bufpool = NULL;      /* defer to aoeblk_gdalloc */
  89         INIT_LIST_HEAD(&d->bufq);
  90         d->next = devlist;
  91         devlist = d;
  92
  93         return d;
  94 }
  95
  96 void
  97 aoedev_downdev(struct aoedev *d)
  98 {
  99         struct frame *f, *e;
 100         struct buf *buf;
 101         struct bio *bio;
 102
 103         f = d->frames;
 104         e = f + d->nframes;
 105         for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
 106                 if (f->tag == FREETAG || f->buf == NULL)
 107                         continue;
 108                 buf = f->buf;
 109                 bio = buf->bio;
 110                 if (--buf->nframesout == 0) {
 111                         mempool_free(buf, d->bufpool);
 112                         bio_endio(bio, bio->bi_size, -EIO);
 113                 }
 114         }
 115         d->inprocess = NULL;
 116
 117         while (!list_empty(&d->bufq)) {
 118                 buf = container_of(d->bufq.next, struct buf, bufs);
 119                 list_del(d->bufq.next);
 120                 bio = buf->bio;
 121                 mempool_free(buf, d->bufpool);
 122                 bio_endio(bio, bio->bi_size, -EIO);
 123         }
 124
 125         if (d->gd)
 126                 d->gd->capacity = 0;
 127
 128         d->flags &= ~(DEVFL_UP | DEVFL_PAUSE);
 129 }
 130
 131 /* find it or malloc it */
 132 struct aoedev *
 133 aoedev_by_sysminor_m(ulong sysminor, ulong bufcnt)
 134 {
 135         struct aoedev *d;
 136         ulong flags;
 137
 138         spin_lock_irqsave(&devlist_lock, flags);
 139
 140         for (d=devlist; d; d=d->next)
 141                 if (d->sysminor == sysminor)
 142                         break;
 143
 144         if (d == NULL) {
 145                 d = aoedev_newdev(bufcnt);
 146                 if (d == NULL) {
 147                         spin_unlock_irqrestore(&devlist_lock, flags);
 148                         printk(KERN_INFO "aoe: aoedev_set: aoedev_newdev failure.\n");
 149                         return NULL;
 150                 }
 151                 d->sysminor = sysminor;
 152                 d->aoemajor = AOEMAJOR(sysminor);
 153                 d->aoeminor = AOEMINOR(sysminor);
 154         }
 155
 156         spin_unlock_irqrestore(&devlist_lock, flags);
 157         return d;
 158 }
 159
 160 static void
 161 aoedev_freedev(struct aoedev *d)
 162 {
 163         if (d->gd) {
 164                 aoedisk_rm_sysfs(d);
 165                 del_gendisk(d->gd);
 166                 put_disk(d->gd);
 167         }
 168         kfree(d->frames);
 169         if (d->bufpool)
 170                 mempool_destroy(d->bufpool);
 171         kfree(d);
 172 }
 173
 174 void
 175 aoedev_exit(void)
 176 {
 177         struct aoedev *d;
 178         ulong flags;
 179
 180         flush_scheduled_work();
 181
 182         while ((d = devlist)) {
 183                 devlist = d->next;
 184
 185                 spin_lock_irqsave(&d->lock, flags);
 186                 aoedev_downdev(d);
 187                 d->flags |= DEVFL_TKILL;
 188                 spin_unlock_irqrestore(&d->lock, flags);
 189
 190                 del_timer_sync(&d->timer);
 191                 aoedev_freedev(d);
 192         }
 193 }
 194
 195 int __init
 196 aoedev_init(void)
 197 {
 198         spin_lock_init(&devlist_lock);
 199         return 0;
 200 }
 201