drivers/block/aoe/aoeblk.c

   1 /* Copyright (c) 2012 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_request(struct request_queue *q)
 165 {
 166         struct aoedev *d;
 167         struct request *rq;
 168
 169         d = q->queuedata;
 170         if ((d->flags & DEVFL_UP) == 0) {
 171                 pr_info_ratelimited("aoe: device %ld.%d is not up\n",
 172                         d->aoemajor, d->aoeminor);
 173                 while ((rq = blk_peek_request(q))) {
 174                         blk_start_request(rq);
 175                         aoe_end_request(d, rq, 1);
 176                 }
 177                 return;
 178         }
 179         aoecmd_work(d);
 180 }
 181
 182 static int
 183 aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 184 {
 185         struct aoedev *d = bdev->bd_disk->private_data;
 186
 187         if ((d->flags & DEVFL_UP) == 0) {
 188                 printk(KERN_ERR "aoe: disk not up\n");
 189                 return -ENODEV;
 190         }
 191
 192         geo->cylinders = d->geo.cylinders;
 193         geo->heads = d->geo.heads;
 194         geo->sectors = d->geo.sectors;
 195         return 0;
 196 }
 197
 198 static const struct block_device_operations aoe_bdops = {
 199         .open = aoeblk_open,
 200         .release = aoeblk_release,
 201         .getgeo = aoeblk_getgeo,
 202         .owner = THIS_MODULE,
 203 };
 204
 205 /* alloc_disk and add_disk can sleep */
 206 void
 207 aoeblk_gdalloc(void *vp)
 208 {
 209         struct aoedev *d = vp;
 210         struct gendisk *gd;
 211         mempool_t *mp;
 212         struct request_queue *q;
 213         enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, };
 214         ulong flags;
 215
 216         gd = alloc_disk(AOE_PARTITIONS);
 217         if (gd == NULL) {
 218                 pr_err("aoe: cannot allocate disk structure for %ld.%d\n",
 219                         d->aoemajor, d->aoeminor);
 220                 goto err;
 221         }
 222
 223         mp = mempool_create(MIN_BUFS, mempool_alloc_slab, mempool_free_slab,
 224                 buf_pool_cache);
 225         if (mp == NULL) {
 226                 printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
 227                         d->aoemajor, d->aoeminor);
 228                 goto err_disk;
 229         }
 230         q = blk_init_queue(aoeblk_request, &d->lock);
 231         if (q == NULL) {
 232                 pr_err("aoe: cannot allocate block queue for %ld.%d\n",
 233                         d->aoemajor, d->aoeminor);
 234                 mempool_destroy(mp);
 235                 goto err_disk;
 236         }
 237
 238         d->blkq = blk_alloc_queue(GFP_KERNEL);
 239         if (!d->blkq)
 240                 goto err_mempool;
 241         d->blkq->backing_dev_info.name = "aoe";
 242         if (bdi_init(&d->blkq->backing_dev_info))
 243                 goto err_blkq;
 244         spin_lock_irqsave(&d->lock, flags);
 245         blk_queue_max_hw_sectors(d->blkq, BLK_DEF_MAX_SECTORS);
 246         q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;
 247         d->bufpool = mp;
 248         d->blkq = gd->queue = q;
 249         q->queuedata = d;
 250         d->gd = gd;
 251         gd->major = AOE_MAJOR;
 252         gd->first_minor = d->sysminor;
 253         gd->fops = &aoe_bdops;
 254         gd->private_data = d;
 255         set_capacity(gd, d->ssize);
 256         snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 257                 d->aoemajor, d->aoeminor);
 258
 259         d->flags &= ~DEVFL_GDALLOC;
 260         d->flags |= DEVFL_UP;
 261
 262         spin_unlock_irqrestore(&d->lock, flags);
 263
 264         add_disk(gd);
 265         aoedisk_add_sysfs(d);
 266         return;
 267
 268 err_blkq:
 269         blk_cleanup_queue(d->blkq);
 270         d->blkq = NULL;
 271 err_mempool:
 272         mempool_destroy(d->bufpool);
 273 err_disk:
 274         put_disk(gd);
 275 err:
 276         spin_lock_irqsave(&d->lock, flags);
 277         d->flags &= ~DEVFL_GDALLOC;
 278         spin_unlock_irqrestore(&d->lock, flags);
 279 }
 280
 281 void
 282 aoeblk_exit(void)
 283 {
 284         kmem_cache_destroy(buf_pool_cache);
 285 }
 286
 287 int __init
 288 aoeblk_init(void)
 289 {
 290         buf_pool_cache = kmem_cache_create("aoe_bufs",
 291                                            sizeof(struct buf),
 292                                            0, 0, NULL);
 293         if (buf_pool_cache == NULL)
 294                 return -ENOMEM;
 295
 296         return 0;
 297 }
 298