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/kernel.h>
   8 #include <linux/hdreg.h>
   9 #include <linux/blkdev.h>
  10 #include <linux/backing-dev.h>
  11 #include <linux/fs.h>
  12 #include <linux/ioctl.h>
  13 #include <linux/slab.h>
  14 #include <linux/ratelimit.h>
  15 #include <linux/genhd.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/mutex.h>
  18 #include <linux/export.h>
  19 #include "aoe.h"
  20
  21 static DEFINE_MUTEX(aoeblk_mutex);
  22 static struct kmem_cache *buf_pool_cache;
  23
  24 static ssize_t aoedisk_show_state(struct device *dev,
  25                                   struct device_attribute *attr, char *page)
  26 {
  27         struct gendisk *disk = dev_to_disk(dev);
  28         struct aoedev *d = disk->private_data;
  29
  30         return snprintf(page, PAGE_SIZE,
  31                         "%s%s\n",
  32                         (d->flags & DEVFL_UP) ? "up" : "down",
  33                         (d->flags & DEVFL_KICKME) ? ",kickme" :
  34                         (d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
  35         /* I'd rather see nopen exported so we can ditch closewait */
  36 }
  37 static ssize_t aoedisk_show_mac(struct device *dev,
  38                                 struct device_attribute *attr, char *page)
  39 {
  40         struct gendisk *disk = dev_to_disk(dev);
  41         struct aoedev *d = disk->private_data;
  42         struct aoetgt *t = d->targets[0];
  43
  44         if (t == NULL)
  45                 return snprintf(page, PAGE_SIZE, "none\n");
  46         return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
  47 }
  48 static ssize_t aoedisk_show_netif(struct device *dev,
  49                                   struct device_attribute *attr, char *page)
  50 {
  51         struct gendisk *disk = dev_to_disk(dev);
  52         struct aoedev *d = disk->private_data;
  53         struct net_device *nds[8], **nd, **nnd, **ne;
  54         struct aoetgt **t, **te;
  55         struct aoeif *ifp, *e;
  56         char *p;
  57
  58         memset(nds, 0, sizeof nds);
  59         nd = nds;
  60         ne = nd + ARRAY_SIZE(nds);
  61         t = d->targets;
  62         te = t + NTARGETS;
  63         for (; t < te && *t; t++) {
  64                 ifp = (*t)->ifs;
  65                 e = ifp + NAOEIFS;
  66                 for (; ifp < e && ifp->nd; ifp++) {
  67                         for (nnd = nds; nnd < nd; nnd++)
  68                                 if (*nnd == ifp->nd)
  69                                         break;
  70                         if (nnd == nd && nd != ne)
  71                                 *nd++ = ifp->nd;
  72                 }
  73         }
  74
  75         ne = nd;
  76         nd = nds;
  77         if (*nd == NULL)
  78                 return snprintf(page, PAGE_SIZE, "none\n");
  79         for (p = page; nd < ne; nd++)
  80                 p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
  81                         p == page ? "" : ",", (*nd)->name);
  82         p += snprintf(p, PAGE_SIZE - (p-page), "\n");
  83         return p-page;
  84 }
  85 /* firmware version */
  86 static ssize_t aoedisk_show_fwver(struct device *dev,
  87                                   struct device_attribute *attr, char *page)
  88 {
  89         struct gendisk *disk = dev_to_disk(dev);
  90         struct aoedev *d = disk->private_data;
  91
  92         return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
  93 }
  94
  95 static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
  96 static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
  97 static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
  98 static struct device_attribute dev_attr_firmware_version = {
  99         .attr = { .name = "firmware-version", .mode = S_IRUGO },
 100         .show = aoedisk_show_fwver,
 101 };
 102
 103 static struct attribute *aoe_attrs[] = {
 104         &dev_attr_state.attr,
 105         &dev_attr_mac.attr,
 106         &dev_attr_netif.attr,
 107         &dev_attr_firmware_version.attr,
 108         NULL,
 109 };
 110
 111 static const struct attribute_group attr_group = {
 112         .attrs = aoe_attrs,
 113 };
 114
 115 static int
 116 aoedisk_add_sysfs(struct aoedev *d)
 117 {
 118         return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 119 }
 120 void
 121 aoedisk_rm_sysfs(struct aoedev *d)
 122 {
 123         sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 124 }
 125
 126 static int
 127 aoeblk_open(struct block_device *bdev, fmode_t mode)
 128 {
 129         struct aoedev *d = bdev->bd_disk->private_data;
 130         ulong flags;
 131
 132         mutex_lock(&aoeblk_mutex);
 133         spin_lock_irqsave(&d->lock, flags);
 134         if (d->flags & DEVFL_UP) {
 135                 d->nopen++;
 136                 spin_unlock_irqrestore(&d->lock, flags);
 137                 mutex_unlock(&aoeblk_mutex);
 138                 return 0;
 139         }
 140         spin_unlock_irqrestore(&d->lock, flags);
 141         mutex_unlock(&aoeblk_mutex);
 142         return -ENODEV;
 143 }
 144
 145 static int
 146 aoeblk_release(struct gendisk *disk, fmode_t mode)
 147 {
 148         struct aoedev *d = disk->private_data;
 149         ulong flags;
 150
 151         spin_lock_irqsave(&d->lock, flags);
 152
 153         if (--d->nopen == 0) {
 154                 spin_unlock_irqrestore(&d->lock, flags);
 155                 aoecmd_cfg(d->aoemajor, d->aoeminor);
 156                 return 0;
 157         }
 158         spin_unlock_irqrestore(&d->lock, flags);
 159
 160         return 0;
 161 }
 162
 163 static void
 164 aoeblk_make_request(struct request_queue *q, struct bio *bio)
 165 {
 166         struct sk_buff_head queue;
 167         struct aoedev *d;
 168         struct buf *buf;
 169         ulong flags;
 170
 171         blk_queue_bounce(q, &bio);
 172
 173         if (bio == NULL) {
 174                 printk(KERN_ERR "aoe: bio is NULL\n");
 175                 BUG();
 176                 return;
 177         }
 178         d = bio->bi_bdev->bd_disk->private_data;
 179         if (d == NULL) {
 180                 printk(KERN_ERR "aoe: bd_disk->private_data is NULL\n");
 181                 BUG();
 182                 bio_endio(bio, -ENXIO);
 183                 return;
 184         } else if (bio->bi_io_vec == NULL) {
 185                 printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
 186                 BUG();
 187                 bio_endio(bio, -ENXIO);
 188                 return;
 189         }
 190         buf = mempool_alloc(d->bufpool, GFP_NOIO);
 191         if (buf == NULL) {
 192                 printk(KERN_INFO "aoe: buf allocation failure\n");
 193                 bio_endio(bio, -ENOMEM);
 194                 return;
 195         }
 196         memset(buf, 0, sizeof(*buf));
 197         INIT_LIST_HEAD(&buf->bufs);
 198         buf->stime = jiffies;
 199         buf->bio = bio;
 200         buf->resid = bio->bi_size;
 201         buf->sector = bio->bi_sector;
 202         buf->bv = &bio->bi_io_vec[bio->bi_idx];
 203         buf->bv_resid = buf->bv->bv_len;
 204         WARN_ON(buf->bv_resid == 0);
 205         buf->bv_off = buf->bv->bv_offset;
 206
 207         spin_lock_irqsave(&d->lock, flags);
 208
 209         if ((d->flags & DEVFL_UP) == 0) {
 210                 pr_info_ratelimited("aoe: device %ld.%d is not up\n",
 211                         d->aoemajor, d->aoeminor);
 212                 spin_unlock_irqrestore(&d->lock, flags);
 213                 mempool_free(buf, d->bufpool);
 214                 bio_endio(bio, -ENXIO);
 215                 return;
 216         }
 217
 218         list_add_tail(&buf->bufs, &d->bufq);
 219
 220         aoecmd_work(d);
 221         __skb_queue_head_init(&queue);
 222         skb_queue_splice_init(&d->sendq, &queue);
 223
 224         spin_unlock_irqrestore(&d->lock, flags);
 225         aoenet_xmit(&queue);
 226 }
 227
 228 static int
 229 aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 230 {
 231         struct aoedev *d = bdev->bd_disk->private_data;
 232
 233         if ((d->flags & DEVFL_UP) == 0) {
 234                 printk(KERN_ERR "aoe: disk not up\n");
 235                 return -ENODEV;
 236         }
 237
 238         geo->cylinders = d->geo.cylinders;
 239         geo->heads = d->geo.heads;
 240         geo->sectors = d->geo.sectors;
 241         return 0;
 242 }
 243
 244 static const struct block_device_operations aoe_bdops = {
 245         .open = aoeblk_open,
 246         .release = aoeblk_release,
 247         .getgeo = aoeblk_getgeo,
 248         .owner = THIS_MODULE,
 249 };
 250
 251 /* alloc_disk and add_disk can sleep */
 252 void
 253 aoeblk_gdalloc(void *vp)
 254 {
 255         struct aoedev *d = vp;
 256         struct gendisk *gd;
 257         ulong flags;
 258
 259         gd = alloc_disk(AOE_PARTITIONS);
 260         if (gd == NULL) {
 261                 printk(KERN_ERR
 262                         "aoe: cannot allocate disk structure for %ld.%d\n",
 263                         d->aoemajor, d->aoeminor);
 264                 goto err;
 265         }
 266
 267         d->bufpool = mempool_create_slab_pool(MIN_BUFS, buf_pool_cache);
 268         if (d->bufpool == NULL) {
 269                 printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
 270                         d->aoemajor, d->aoeminor);
 271                 goto err_disk;
 272         }
 273
 274         d->blkq = blk_alloc_queue(GFP_KERNEL);
 275         if (!d->blkq)
 276                 goto err_mempool;
 277         blk_queue_make_request(d->blkq, aoeblk_make_request);
 278         d->blkq->backing_dev_info.name = "aoe";
 279         if (bdi_init(&d->blkq->backing_dev_info))
 280                 goto err_blkq;
 281         spin_lock_irqsave(&d->lock, flags);
 282         gd->major = AOE_MAJOR;
 283         gd->first_minor = d->sysminor * AOE_PARTITIONS;
 284         gd->fops = &aoe_bdops;
 285         gd->private_data = d;
 286         set_capacity(gd, d->ssize);
 287         snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 288                 d->aoemajor, d->aoeminor);
 289
 290         gd->queue = d->blkq;
 291         d->gd = gd;
 292         d->flags &= ~DEVFL_GDALLOC;
 293         d->flags |= DEVFL_UP;
 294
 295         spin_unlock_irqrestore(&d->lock, flags);
 296
 297         add_disk(gd);
 298         aoedisk_add_sysfs(d);
 299         return;
 300
 301 err_blkq:
 302         blk_cleanup_queue(d->blkq);
 303         d->blkq = NULL;
 304 err_mempool:
 305         mempool_destroy(d->bufpool);
 306 err_disk:
 307         put_disk(gd);
 308 err:
 309         spin_lock_irqsave(&d->lock, flags);
 310         d->flags &= ~DEVFL_GDALLOC;
 311         spin_unlock_irqrestore(&d->lock, flags);
 312 }
 313
 314 void
 315 aoeblk_exit(void)
 316 {
 317         kmem_cache_destroy(buf_pool_cache);
 318 }
 319
 320 int __init
 321 aoeblk_init(void)
 322 {
 323         buf_pool_cache = kmem_cache_create("aoe_bufs",
 324                                            sizeof(struct buf),
 325                                            0, 0, NULL);
 326         if (buf_pool_cache == NULL)
 327                 return -ENOMEM;
 328
 329         return 0;
 330 }
 331