drivers/block/aoe/aoedev.c

   1 /* Copyright (c) 2004 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 struct aoedev *
  16 aoedev_bymac(unsigned char *macaddr)
  17 {
  18         struct aoedev *d;
  19         ulong flags;
  20
  21         spin_lock_irqsave(&devlist_lock, flags);
  22
  23         for (d=devlist; d; d=d->next)
  24                 if (!memcmp(d->addr, macaddr, 6))
  25                         break;
  26
  27         spin_unlock_irqrestore(&devlist_lock, flags);
  28         return d;
  29 }
  30
  31 /* called with devlist lock held */
  32 static struct aoedev *
  33 aoedev_newdev(ulong nframes)
  34 {
  35         struct aoedev *d;
  36         struct frame *f, *e;
  37
  38         d = kcalloc(1, sizeof *d, GFP_ATOMIC);
  39         if (d == NULL)
  40                 return NULL;
  41         f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
  42         if (f == NULL) {
  43                 kfree(d);
  44                 return NULL;
  45         }
  46
  47         d->nframes = nframes;
  48         d->frames = f;
  49         e = f + nframes;
  50         for (; f<e; f++)
  51                 f->tag = FREETAG;
  52
  53         spin_lock_init(&d->lock);
  54         init_timer(&d->timer);
  55         d->bufpool = NULL;      /* defer to aoeblk_gdalloc */
  56         INIT_LIST_HEAD(&d->bufq);
  57         d->next = devlist;
  58         devlist = d;
  59
  60         return d;
  61 }
  62
  63 void
  64 aoedev_downdev(struct aoedev *d)
  65 {
  66         struct frame *f, *e;
  67         struct buf *buf;
  68         struct bio *bio;
  69
  70         d->flags |= DEVFL_TKILL;
  71         del_timer(&d->timer);
  72
  73         f = d->frames;
  74         e = f + d->nframes;
  75         for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
  76                 if (f->tag == FREETAG || f->buf == NULL)
  77                         continue;
  78                 buf = f->buf;
  79                 bio = buf->bio;
  80                 if (--buf->nframesout == 0) {
  81                         mempool_free(buf, d->bufpool);
  82                         bio_endio(bio, bio->bi_size, -EIO);
  83                 }
  84         }
  85         d->inprocess = NULL;
  86
  87         while (!list_empty(&d->bufq)) {
  88                 buf = container_of(d->bufq.next, struct buf, bufs);
  89                 list_del(d->bufq.next);
  90                 bio = buf->bio;
  91                 mempool_free(buf, d->bufpool);
  92                 bio_endio(bio, bio->bi_size, -EIO);
  93         }
  94
  95         if (d->nopen)
  96                 d->flags |= DEVFL_CLOSEWAIT;
  97         if (d->gd)
  98                 d->gd->capacity = 0;
  99
 100         d->flags &= ~DEVFL_UP;
 101 }
 102
 103 struct aoedev *
 104 aoedev_set(ulong sysminor, unsigned char *addr, struct net_device *ifp, ulong bufcnt)
 105 {
 106         struct aoedev *d;
 107         ulong flags;
 108
 109         spin_lock_irqsave(&devlist_lock, flags);
 110
 111         for (d=devlist; d; d=d->next)
 112                 if (d->sysminor == sysminor
 113                 || memcmp(d->addr, addr, sizeof d->addr) == 0)
 114                         break;
 115
 116         if (d == NULL && (d = aoedev_newdev(bufcnt)) == NULL) {
 117                 spin_unlock_irqrestore(&devlist_lock, flags);
 118                 printk(KERN_INFO "aoe: aoedev_set: aoedev_newdev failure.\n");
 119                 return NULL;
 120         }
 121
 122         spin_unlock_irqrestore(&devlist_lock, flags);
 123         spin_lock_irqsave(&d->lock, flags);
 124
 125         d->ifp = ifp;
 126
 127         if (d->sysminor != sysminor
 128         || memcmp(d->addr, addr, sizeof d->addr)
 129         || (d->flags & DEVFL_UP) == 0) {
 130                 aoedev_downdev(d); /* flushes outstanding frames */
 131                 memcpy(d->addr, addr, sizeof d->addr);
 132                 d->sysminor = sysminor;
 133                 d->aoemajor = AOEMAJOR(sysminor);
 134                 d->aoeminor = AOEMINOR(sysminor);
 135         }
 136
 137         spin_unlock_irqrestore(&d->lock, flags);
 138         return d;
 139 }
 140
 141 static void
 142 aoedev_freedev(struct aoedev *d)
 143 {
 144         if (d->gd) {
 145                 aoedisk_rm_sysfs(d);
 146                 del_gendisk(d->gd);
 147                 put_disk(d->gd);
 148         }
 149         kfree(d->frames);
 150         mempool_destroy(d->bufpool);
 151         kfree(d);
 152 }
 153
 154 void
 155 aoedev_exit(void)
 156 {
 157         struct aoedev *d;
 158         ulong flags;
 159
 160         flush_scheduled_work();
 161
 162         while ((d = devlist)) {
 163                 devlist = d->next;
 164
 165                 spin_lock_irqsave(&d->lock, flags);
 166                 aoedev_downdev(d);
 167                 spin_unlock_irqrestore(&d->lock, flags);
 168
 169                 del_timer_sync(&d->timer);
 170                 aoedev_freedev(d);
 171         }
 172 }
 173
 174 int __init
 175 aoedev_init(void)
 176 {
 177         spin_lock_init(&devlist_lock);
 178         return 0;
 179 }
 180