release/src-rt-6.x.4708/linux/linux-2.6.36/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 <linux/smp_lock.h>
  16 #include "aoe.h"
  17
  18 static struct kmem_cache *buf_pool_cache;
  19
  20 static ssize_t aoedisk_show_state(struct device *dev,
  21                                   struct device_attribute *attr, char *page)
  22 {
  23         struct gendisk *disk = dev_to_disk(dev);
  24         struct aoedev *d = disk->private_data;
  25
  26         return snprintf(page, PAGE_SIZE,
  27                         "%s%s\n",
  28                         (d->flags & DEVFL_UP) ? "up" : "down",
  29                         (d->flags & DEVFL_KICKME) ? ",kickme" :
  30                         (d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
  31         /* I'd rather see nopen exported so we can ditch closewait */
  32 }
  33 static ssize_t aoedisk_show_mac(struct device *dev,
  34                                 struct device_attribute *attr, char *page)
  35 {
  36         struct gendisk *disk = dev_to_disk(dev);
  37         struct aoedev *d = disk->private_data;
  38         struct aoetgt *t = d->targets[0];
  39
  40         if (t == NULL)
  41                 return snprintf(page, PAGE_SIZE, "none\n");
  42         return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
  43 }
  44 static ssize_t aoedisk_show_netif(struct device *dev,
  45                                   struct device_attribute *attr, char *page)
  46 {
  47         struct gendisk *disk = dev_to_disk(dev);
  48         struct aoedev *d = disk->private_data;
  49         struct net_device *nds[8], **nd, **nnd, **ne;
  50         struct aoetgt **t, **te;
  51         struct aoeif *ifp, *e;
  52         char *p;
  53
  54         memset(nds, 0, sizeof nds);
  55         nd = nds;
  56         ne = nd + ARRAY_SIZE(nds);
  57         t = d->targets;
  58         te = t + NTARGETS;
  59         for (; t < te && *t; t++) {
  60                 ifp = (*t)->ifs;
  61                 e = ifp + NAOEIFS;
  62                 for (; ifp < e && ifp->nd; ifp++) {
  63                         for (nnd = nds; nnd < nd; nnd++)
  64                                 if (*nnd == ifp->nd)
  65                                         break;
  66                         if (nnd == nd && nd != ne)
  67                                 *nd++ = ifp->nd;
  68                 }
  69         }
  70
  71         ne = nd;
  72         nd = nds;
  73         if (*nd == NULL)
  74                 return snprintf(page, PAGE_SIZE, "none\n");
  75         for (p = page; nd < ne; nd++)
  76                 p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
  77                         p == page ? "" : ",", (*nd)->name);
  78         p += snprintf(p, PAGE_SIZE - (p-page), "\n");
  79         return p-page;
  80 }
  81 /* firmware version */
  82 static ssize_t aoedisk_show_fwver(struct device *dev,
  83                                   struct device_attribute *attr, char *page)
  84 {
  85         struct gendisk *disk = dev_to_disk(dev);
  86         struct aoedev *d = disk->private_data;
  87
  88         return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
  89 }
  90
  91 static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
  92 static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
  93 static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
  94 static struct device_attribute dev_attr_firmware_version = {
  95         .attr = { .name = "firmware-version", .mode = S_IRUGO },
  96         .show = aoedisk_show_fwver,
  97 };
  98
  99 static struct attribute *aoe_attrs[] = {
 100         &dev_attr_state.attr,
 101         &dev_attr_mac.attr,
 102         &dev_attr_netif.attr,
 103         &dev_attr_firmware_version.attr,
 104         NULL,
 105 };
 106
 107 static const struct attribute_group attr_group = {
 108         .attrs = aoe_attrs,
 109 };
 110
 111 static int
 112 aoedisk_add_sysfs(struct aoedev *d)
 113 {
 114         return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 115 }
 116 void
 117 aoedisk_rm_sysfs(struct aoedev *d)
 118 {
 119         sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 120 }
 121
 122 static int
 123 aoeblk_open(struct block_device *bdev, fmode_t mode)
 124 {
 125         struct aoedev *d = bdev->bd_disk->private_data;
 126         ulong flags;
 127
 128         lock_kernel();
 129         spin_lock_irqsave(&d->lock, flags);
 130         if (d->flags & DEVFL_UP) {
 131                 d->nopen++;
 132                 spin_unlock_irqrestore(&d->lock, flags);
 133                 unlock_kernel();
 134                 return 0;
 135         }
 136         spin_unlock_irqrestore(&d->lock, flags);
 137         unlock_kernel();
 138         return -ENODEV;
 139 }
 140
 141 static int
 142 aoeblk_release(struct gendisk *disk, fmode_t mode)
 143 {
 144         struct aoedev *d = disk->private_data;
 145         ulong flags;
 146
 147         spin_lock_irqsave(&d->lock, flags);
 148
 149         if (--d->nopen == 0) {
 150                 spin_unlock_irqrestore(&d->lock, flags);
 151                 aoecmd_cfg(d->aoemajor, d->aoeminor);
 152                 return 0;
 153         }
 154         spin_unlock_irqrestore(&d->lock, flags);
 155
 156         return 0;
 157 }
 158
 159 static int
 160 aoeblk_make_request(struct request_queue *q, struct bio *bio)
 161 {
 162         struct sk_buff_head queue;
 163         struct aoedev *d;
 164         struct buf *buf;
 165         ulong flags;
 166
 167         blk_queue_bounce(q, &bio);
 168
 169         if (bio == NULL) {
 170                 printk(KERN_ERR "aoe: bio is NULL\n");
 171                 BUG();
 172                 return 0;
 173         }
 174         d = bio->bi_bdev->bd_disk->private_data;
 175         if (d == NULL) {
 176                 printk(KERN_ERR "aoe: bd_disk->private_data is NULL\n");
 177                 BUG();
 178                 bio_endio(bio, -ENXIO);
 179                 return 0;
 180         } else if (bio->bi_rw & REQ_HARDBARRIER) {
 181                 bio_endio(bio, -EOPNOTSUPP);
 182                 return 0;
 183         } else if (bio->bi_io_vec == NULL) {
 184                 printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
 185                 BUG();
 186                 bio_endio(bio, -ENXIO);
 187                 return 0;
 188         }
 189         buf = mempool_alloc(d->bufpool, GFP_NOIO);
 190         if (buf == NULL) {
 191                 printk(KERN_INFO "aoe: buf allocation failure\n");
 192                 bio_endio(bio, -ENOMEM);
 193                 return 0;
 194         }
 195         memset(buf, 0, sizeof(*buf));
 196         INIT_LIST_HEAD(&buf->bufs);
 197         buf->stime = jiffies;
 198         buf->bio = bio;
 199         buf->resid = bio->bi_size;
 200         buf->sector = bio->bi_sector;
 201         buf->bv = &bio->bi_io_vec[bio->bi_idx];
 202         buf->bv_resid = buf->bv->bv_len;
 203         WARN_ON(buf->bv_resid == 0);
 204         buf->bv_off = buf->bv->bv_offset;
 205
 206         spin_lock_irqsave(&d->lock, flags);
 207
 208         if ((d->flags & DEVFL_UP) == 0) {
 209                 printk(KERN_INFO "aoe: device %ld.%d is not up\n",
 210                         d->aoemajor, d->aoeminor);
 211                 spin_unlock_irqrestore(&d->lock, flags);
 212                 mempool_free(buf, d->bufpool);
 213                 bio_endio(bio, -ENXIO);
 214                 return 0;
 215         }
 216
 217         list_add_tail(&buf->bufs, &d->bufq);
 218
 219         aoecmd_work(d);
 220         __skb_queue_head_init(&queue);
 221         skb_queue_splice_init(&d->sendq, &queue);
 222
 223         spin_unlock_irqrestore(&d->lock, flags);
 224         aoenet_xmit(&queue);
 225
 226         return 0;
 227 }
 228
 229 static int
 230 aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 231 {
 232         struct aoedev *d = bdev->bd_disk->private_data;
 233
 234         if ((d->flags & DEVFL_UP) == 0) {
 235                 printk(KERN_ERR "aoe: disk not up\n");
 236                 return -ENODEV;
 237         }
 238
 239         geo->cylinders = d->geo.cylinders;
 240         geo->heads = d->geo.heads;
 241         geo->sectors = d->geo.sectors;
 242         return 0;
 243 }
 244
 245 static const struct block_device_operations aoe_bdops = {
 246         .open = aoeblk_open,
 247         .release = aoeblk_release,
 248         .getgeo = aoeblk_getgeo,
 249         .owner = THIS_MODULE,
 250 };
 251
 252 /* alloc_disk and add_disk can sleep */
 253 void
 254 aoeblk_gdalloc(void *vp)
 255 {
 256         struct aoedev *d = vp;
 257         struct gendisk *gd;
 258         ulong flags;
 259
 260         gd = alloc_disk(AOE_PARTITIONS);
 261         if (gd == NULL) {
 262                 printk(KERN_ERR
 263                         "aoe: cannot allocate disk structure for %ld.%d\n",
 264                         d->aoemajor, d->aoeminor);
 265                 goto err;
 266         }
 267
 268         d->bufpool = mempool_create_slab_pool(MIN_BUFS, buf_pool_cache);
 269         if (d->bufpool == NULL) {
 270                 printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
 271                         d->aoemajor, d->aoeminor);
 272                 goto err_disk;
 273         }
 274
 275         d->blkq = blk_alloc_queue(GFP_KERNEL);
 276         if (!d->blkq)
 277                 goto err_mempool;
 278         blk_queue_make_request(d->blkq, aoeblk_make_request);
 279         d->blkq->backing_dev_info.name = "aoe";
 280         if (bdi_init(&d->blkq->backing_dev_info))
 281                 goto err_blkq;
 282         spin_lock_irqsave(&d->lock, flags);
 283         gd->major = AOE_MAJOR;
 284         gd->first_minor = d->sysminor * AOE_PARTITIONS;
 285         gd->fops = &aoe_bdops;
 286         gd->private_data = d;
 287         set_capacity(gd, d->ssize);
 288         snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 289                 d->aoemajor, d->aoeminor);
 290
 291         gd->queue = d->blkq;
 292         d->gd = gd;
 293         d->flags &= ~DEVFL_GDALLOC;
 294         d->flags |= DEVFL_UP;
 295
 296         spin_unlock_irqrestore(&d->lock, flags);
 297
 298         add_disk(gd);
 299         aoedisk_add_sysfs(d);
 300         return;
 301
 302 err_blkq:
 303         blk_cleanup_queue(d->blkq);
 304         d->blkq = NULL;
 305 err_mempool:
 306         mempool_destroy(d->bufpool);
 307 err_disk:
 308         put_disk(gd);
 309 err:
 310         spin_lock_irqsave(&d->lock, flags);
 311         d->flags &= ~DEVFL_GDALLOC;
 312         spin_unlock_irqrestore(&d->lock, flags);
 313 }
 314
 315 void
 316 aoeblk_exit(void)
 317 {
 318         kmem_cache_destroy(buf_pool_cache);
 319 }
 320
 321 int __init
 322 aoeblk_init(void)
 323 {
 324         buf_pool_cache = kmem_cache_create("aoe_bufs",
 325                                            sizeof(struct buf),
 326                                            0, 0, NULL);
 327         if (buf_pool_cache == NULL)
 328                 return -ENOMEM;
 329
 330         return 0;
 331 }