linux/drivers/block/aoe/aoeblk.c
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   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
  21static DEFINE_MUTEX(aoeblk_mutex);
  22static struct kmem_cache *buf_pool_cache;
  23
  24static 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}
  37static 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}
  48static 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 */
  86static 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
  95static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
  96static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
  97static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
  98static struct device_attribute dev_attr_firmware_version = {
  99        .attr = { .name = "firmware-version", .mode = S_IRUGO },
 100        .show = aoedisk_show_fwver,
 101};
 102
 103static 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
 111static const struct attribute_group attr_group = {
 112        .attrs = aoe_attrs,
 113};
 114
 115static int
 116aoedisk_add_sysfs(struct aoedev *d)
 117{
 118        return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 119}
 120void
 121aoedisk_rm_sysfs(struct aoedev *d)
 122{
 123        sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 124}
 125
 126static int
 127aoeblk_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
 145static int
 146aoeblk_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
 163static void
 164aoeblk_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
 228static int
 229aoeblk_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
 244static 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 */
 252void
 253aoeblk_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
 301err_blkq:
 302        blk_cleanup_queue(d->blkq);
 303        d->blkq = NULL;
 304err_mempool:
 305        mempool_destroy(d->bufpool);
 306err_disk:
 307        put_disk(gd);
 308err:
 309        spin_lock_irqsave(&d->lock, flags);
 310        d->flags &= ~DEVFL_GDALLOC;
 311        spin_unlock_irqrestore(&d->lock, flags);
 312}
 313
 314void
 315aoeblk_exit(void)
 316{
 317        kmem_cache_destroy(buf_pool_cache);
 318}
 319
 320int __init
 321aoeblk_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
 332
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