drivers/block/aoe/aoeblk.c

   1 /* Copyright (c) 2007 Coraid, Inc.  See COPYING for GPL terms. */
   2 /*
   3  * aoeblk.c
   4  * block device routines
   5  */
   6
   7 #include <linux/hdreg.h>
   8 #include <linux/blkdev.h>
   9 #include <linux/backing-dev.h>
  10 #include <linux/fs.h>
  11 #include <linux/ioctl.h>
  12 #include <linux/slab.h>
  13 #include <linux/genhd.h>
  14 #include <linux/netdevice.h>
  15 #include "aoe.h"
  16
  17 static struct kmem_cache *buf_pool_cache;
  18
  19 static ssize_t aoedisk_show_state(struct device *dev,
  20                                   struct device_attribute *attr, char *page)
  21 {
  22         struct gendisk *disk = dev_to_disk(dev);
  23         struct aoedev *d = disk->private_data;
  24
  25         return snprintf(page, PAGE_SIZE,
  26                         "%s%s\n",
  27                         (d->flags & DEVFL_UP) ? "up" : "down",
  28                         (d->flags & DEVFL_KICKME) ? ",kickme" :
  29                         (d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
  30         /* I'd rather see nopen exported so we can ditch closewait */
  31 }
  32 static ssize_t aoedisk_show_mac(struct device *dev,
  33                                 struct device_attribute *attr, char *page)
  34 {
  35         struct gendisk *disk = dev_to_disk(dev);
  36         struct aoedev *d = disk->private_data;
  37         struct aoetgt *t = d->targets[0];
  38
  39         if (t == NULL)
  40                 return snprintf(page, PAGE_SIZE, "none\n");
  41         return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
  42 }
  43 static ssize_t aoedisk_show_netif(struct device *dev,
  44                                   struct device_attribute *attr, char *page)
  45 {
  46         struct gendisk *disk = dev_to_disk(dev);
  47         struct aoedev *d = disk->private_data;
  48         struct net_device *nds[8], **nd, **nnd, **ne;
  49         struct aoetgt **t, **te;
  50         struct aoeif *ifp, *e;
  51         char *p;
  52
  53         memset(nds, 0, sizeof nds);
  54         nd = nds;
  55         ne = nd + ARRAY_SIZE(nds);
  56         t = d->targets;
  57         te = t + NTARGETS;
  58         for (; t < te && *t; t++) {
  59                 ifp = (*t)->ifs;
  60                 e = ifp + NAOEIFS;
  61                 for (; ifp < e && ifp->nd; ifp++) {
  62                         for (nnd = nds; nnd < nd; nnd++)
  63                                 if (*nnd == ifp->nd)
  64                                         break;
  65                         if (nnd == nd && nd != ne)
  66                                 *nd++ = ifp->nd;
  67                 }
  68         }
  69
  70         ne = nd;
  71         nd = nds;
  72         if (*nd == NULL)
  73                 return snprintf(page, PAGE_SIZE, "none\n");
  74         for (p = page; nd < ne; nd++)
  75                 p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
  76                         p == page ? "" : ",", (*nd)->name);
  77         p += snprintf(p, PAGE_SIZE - (p-page), "\n");
  78         return p-page;
  79 }
  80 /* firmware version */
  81 static ssize_t aoedisk_show_fwver(struct device *dev,
  82                                   struct device_attribute *attr, char *page)
  83 {
  84         struct gendisk *disk = dev_to_disk(dev);
  85         struct aoedev *d = disk->private_data;
  86
  87         return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
  88 }
  89
  90 static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
  91 static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
  92 static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
  93 static struct device_attribute dev_attr_firmware_version = {
  94         .attr = { .name = "firmware-version", .mode = S_IRUGO },
  95         .show = aoedisk_show_fwver,
  96 };
  97
  98 static struct attribute *aoe_attrs[] = {
  99         &dev_attr_state.attr,
 100         &dev_attr_mac.attr,
 101         &dev_attr_netif.attr,
 102         &dev_attr_firmware_version.attr,
 103         NULL,
 104 };
 105
 106 static const struct attribute_group attr_group = {
 107         .attrs = aoe_attrs,
 108 };
 109
 110 static int
 111 aoedisk_add_sysfs(struct aoedev *d)
 112 {
 113         return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 114 }
 115 void
 116 aoedisk_rm_sysfs(struct aoedev *d)
 117 {
 118         sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 119 }
 120
 121 static int
 122 aoeblk_open(struct block_device *bdev, fmode_t mode)
 123 {
 124         struct aoedev *d = bdev->bd_disk->private_data;
 125         ulong flags;
 126
 127         spin_lock_irqsave(&d->lock, flags);
 128         if (d->flags & DEVFL_UP) {
 129                 d->nopen++;
 130                 spin_unlock_irqrestore(&d->lock, flags);
 131                 return 0;
 132         }
 133         spin_unlock_irqrestore(&d->lock, flags);
 134         return -ENODEV;
 135 }
 136
 137 static int
 138 aoeblk_release(struct gendisk *disk, fmode_t mode)
 139 {
 140         struct aoedev *d = disk->private_data;
 141         ulong flags;
 142
 143         spin_lock_irqsave(&d->lock, flags);
 144
 145         if (--d->nopen == 0) {
 146                 spin_unlock_irqrestore(&d->lock, flags);
 147                 aoecmd_cfg(d->aoemajor, d->aoeminor);
 148                 return 0;
 149         }
 150         spin_unlock_irqrestore(&d->lock, flags);
 151
 152         return 0;
 153 }
 154
 155 static int
 156 aoeblk_make_request(struct request_queue *q, struct bio *bio)
 157 {
 158         struct sk_buff_head queue;
 159         struct aoedev *d;
 160         struct buf *buf;
 161         ulong flags;
 162
 163         blk_queue_bounce(q, &bio);
 164
 165         if (bio == NULL) {
 166                 printk(KERN_ERR "aoe: bio is NULL\n");
 167                 BUG();
 168                 return 0;
 169         }
 170         d = bio->bi_bdev->bd_disk->private_data;
 171         if (d == NULL) {
 172                 printk(KERN_ERR "aoe: bd_disk->private_data is NULL\n");
 173                 BUG();
 174                 bio_endio(bio, -ENXIO);
 175                 return 0;
 176         } else if (bio_rw_flagged(bio, BIO_RW_BARRIER)) {
 177                 bio_endio(bio, -EOPNOTSUPP);
 178                 return 0;
 179         } else if (bio->bi_io_vec == NULL) {
 180                 printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
 181                 BUG();
 182                 bio_endio(bio, -ENXIO);
 183                 return 0;
 184         }
 185         buf = mempool_alloc(d->bufpool, GFP_NOIO);
 186         if (buf == NULL) {
 187                 printk(KERN_INFO "aoe: buf allocation failure\n");
 188                 bio_endio(bio, -ENOMEM);
 189                 return 0;
 190         }
 191         memset(buf, 0, sizeof(*buf));
 192         INIT_LIST_HEAD(&buf->bufs);
 193         buf->stime = jiffies;
 194         buf->bio = bio;
 195         buf->resid = bio->bi_size;
 196         buf->sector = bio->bi_sector;
 197         buf->bv = &bio->bi_io_vec[bio->bi_idx];
 198         buf->bv_resid = buf->bv->bv_len;
 199         WARN_ON(buf->bv_resid == 0);
 200         buf->bv_off = buf->bv->bv_offset;
 201
 202         spin_lock_irqsave(&d->lock, flags);
 203
 204         if ((d->flags & DEVFL_UP) == 0) {
 205                 printk(KERN_INFO "aoe: device %ld.%d is not up\n",
 206                         d->aoemajor, d->aoeminor);
 207                 spin_unlock_irqrestore(&d->lock, flags);
 208                 mempool_free(buf, d->bufpool);
 209                 bio_endio(bio, -ENXIO);
 210                 return 0;
 211         }
 212
 213         list_add_tail(&buf->bufs, &d->bufq);
 214
 215         aoecmd_work(d);
 216         __skb_queue_head_init(&queue);
 217         skb_queue_splice_init(&d->sendq, &queue);
 218
 219         spin_unlock_irqrestore(&d->lock, flags);
 220         aoenet_xmit(&queue);
 221
 222         return 0;
 223 }
 224
 225 static int
 226 aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 227 {
 228         struct aoedev *d = bdev->bd_disk->private_data;
 229
 230         if ((d->flags & DEVFL_UP) == 0) {
 231                 printk(KERN_ERR "aoe: disk not up\n");
 232                 return -ENODEV;
 233         }
 234
 235         geo->cylinders = d->geo.cylinders;
 236         geo->heads = d->geo.heads;
 237         geo->sectors = d->geo.sectors;
 238         return 0;
 239 }
 240
 241 static const struct block_device_operations aoe_bdops = {
 242         .open = aoeblk_open,
 243         .release = aoeblk_release,
 244         .getgeo = aoeblk_getgeo,
 245         .owner = THIS_MODULE,
 246 };
 247
 248 /* alloc_disk and add_disk can sleep */
 249 void
 250 aoeblk_gdalloc(void *vp)
 251 {
 252         struct aoedev *d = vp;
 253         struct gendisk *gd;
 254         ulong flags;
 255
 256         gd = alloc_disk(AOE_PARTITIONS);
 257         if (gd == NULL) {
 258                 printk(KERN_ERR
 259                         "aoe: cannot allocate disk structure for %ld.%d\n",
 260                         d->aoemajor, d->aoeminor);
 261                 goto err;
 262         }
 263
 264         d->bufpool = mempool_create_slab_pool(MIN_BUFS, buf_pool_cache);
 265         if (d->bufpool == NULL) {
 266                 printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
 267                         d->aoemajor, d->aoeminor);
 268                 goto err_disk;
 269         }
 270
 271         d->blkq = blk_alloc_queue(GFP_KERNEL);
 272         if (!d->blkq)
 273                 goto err_mempool;
 274         blk_queue_make_request(d->blkq, aoeblk_make_request);
 275         d->blkq->backing_dev_info.name = "aoe";
 276         if (bdi_init(&d->blkq->backing_dev_info))
 277                 goto err_blkq;
 278         spin_lock_irqsave(&d->lock, flags);
 279         gd->major = AOE_MAJOR;
 280         gd->first_minor = d->sysminor * AOE_PARTITIONS;
 281         gd->fops = &aoe_bdops;
 282         gd->private_data = d;
 283         set_capacity(gd, d->ssize);
 284         snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 285                 d->aoemajor, d->aoeminor);
 286
 287         gd->queue = d->blkq;
 288         d->gd = gd;
 289         d->flags &= ~DEVFL_GDALLOC;
 290         d->flags |= DEVFL_UP;
 291
 292         spin_unlock_irqrestore(&d->lock, flags);
 293
 294         add_disk(gd);
 295         aoedisk_add_sysfs(d);
 296         return;
 297
 298 err_blkq:
 299         blk_cleanup_queue(d->blkq);
 300         d->blkq = NULL;
 301 err_mempool:
 302         mempool_destroy(d->bufpool);
 303 err_disk:
 304         put_disk(gd);
 305 err:
 306         spin_lock_irqsave(&d->lock, flags);
 307         d->flags &= ~DEVFL_GDALLOC;
 308         spin_unlock_irqrestore(&d->lock, flags);
 309 }
 310
 311 void
 312 aoeblk_exit(void)
 313 {
 314         kmem_cache_destroy(buf_pool_cache);
 315 }
 316
 317 int __init
 318 aoeblk_init(void)
 319 {
 320         buf_pool_cache = kmem_cache_create("aoe_bufs",
 321                                            sizeof(struct buf),
 322                                            0, 0, NULL);
 323         if (buf_pool_cache == NULL)
 324                 return -ENOMEM;
 325
 326         return 0;
 327 }
 328