kernel/fs/nfs/blocklayout/dev.c

   1 /*
   2  * Copyright (c) 2014 Christoph Hellwig.
   3  */
   4 #include <linux/sunrpc/svc.h>
   5 #include <linux/blkdev.h>
   6 #include <linux/nfs4.h>
   7 #include <linux/nfs_fs.h>
   8 #include <linux/nfs_xdr.h>
   9
  10 #include "blocklayout.h"
  11
  12 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  13
  14 static void
  15 bl_free_device(struct pnfs_block_dev *dev)
  16 {
  17         if (dev->nr_children) {
  18                 int i;
  19
  20                 for (i = 0; i < dev->nr_children; i++)
  21                         bl_free_device(&dev->children[i]);
  22                 kfree(dev->children);
  23         } else {
  24                 if (dev->bdev)
  25                         blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE);
  26         }
  27 }
  28
  29 void
  30 bl_free_deviceid_node(struct nfs4_deviceid_node *d)
  31 {
  32         struct pnfs_block_dev *dev =
  33                 container_of(d, struct pnfs_block_dev, node);
  34
  35         bl_free_device(dev);
  36         kfree_rcu(dev, node.rcu);
  37 }
  38
  39 static int
  40 nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
  41 {
  42         __be32 *p;
  43         int i;
  44
  45         p = xdr_inline_decode(xdr, 4);
  46         if (!p)
  47                 return -EIO;
  48         b->type = be32_to_cpup(p++);
  49
  50         switch (b->type) {
  51         case PNFS_BLOCK_VOLUME_SIMPLE:
  52                 p = xdr_inline_decode(xdr, 4);
  53                 if (!p)
  54                         return -EIO;
  55                 b->simple.nr_sigs = be32_to_cpup(p++);
  56                 if (!b->simple.nr_sigs) {
  57                         dprintk("no signature\n");
  58                         return -EIO;
  59                 }
  60
  61                 b->simple.len = 4 + 4;
  62                 for (i = 0; i < b->simple.nr_sigs; i++) {
  63                         p = xdr_inline_decode(xdr, 8 + 4);
  64                         if (!p)
  65                                 return -EIO;
  66                         p = xdr_decode_hyper(p, &b->simple.sigs[i].offset);
  67                         b->simple.sigs[i].sig_len = be32_to_cpup(p++);
  68                         if (b->simple.sigs[i].sig_len > PNFS_BLOCK_UUID_LEN) {
  69                                 pr_info("signature too long: %d\n",
  70                                         b->simple.sigs[i].sig_len);
  71                                 return -EIO;
  72                         }
  73
  74                         p = xdr_inline_decode(xdr, b->simple.sigs[i].sig_len);
  75                         if (!p)
  76                                 return -EIO;
  77                         memcpy(&b->simple.sigs[i].sig, p,
  78                                 b->simple.sigs[i].sig_len);
  79
  80                         b->simple.len += 8 + 4 + b->simple.sigs[i].sig_len;
  81                 }
  82                 break;
  83         case PNFS_BLOCK_VOLUME_SLICE:
  84                 p = xdr_inline_decode(xdr, 8 + 8 + 4);
  85                 if (!p)
  86                         return -EIO;
  87                 p = xdr_decode_hyper(p, &b->slice.start);
  88                 p = xdr_decode_hyper(p, &b->slice.len);
  89                 b->slice.volume = be32_to_cpup(p++);
  90                 break;
  91         case PNFS_BLOCK_VOLUME_CONCAT:
  92                 p = xdr_inline_decode(xdr, 4);
  93                 if (!p)
  94                         return -EIO;
  95                 b->concat.volumes_count = be32_to_cpup(p++);
  96
  97                 p = xdr_inline_decode(xdr, b->concat.volumes_count * 4);
  98                 if (!p)
  99                         return -EIO;
 100                 for (i = 0; i < b->concat.volumes_count; i++)
 101                         b->concat.volumes[i] = be32_to_cpup(p++);
 102                 break;
 103         case PNFS_BLOCK_VOLUME_STRIPE:
 104                 p = xdr_inline_decode(xdr, 8 + 4);
 105                 if (!p)
 106                         return -EIO;
 107                 p = xdr_decode_hyper(p, &b->stripe.chunk_size);
 108                 b->stripe.volumes_count = be32_to_cpup(p++);
 109
 110                 p = xdr_inline_decode(xdr, b->stripe.volumes_count * 4);
 111                 if (!p)
 112                         return -EIO;
 113                 for (i = 0; i < b->stripe.volumes_count; i++)
 114                         b->stripe.volumes[i] = be32_to_cpup(p++);
 115                 break;
 116         default:
 117                 dprintk("unknown volume type!\n");
 118                 return -EIO;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static bool bl_map_simple(struct pnfs_block_dev *dev, u64 offset,
 125                 struct pnfs_block_dev_map *map)
 126 {
 127         map->start = dev->start;
 128         map->len = dev->len;
 129         map->disk_offset = dev->disk_offset;
 130         map->bdev = dev->bdev;
 131         return true;
 132 }
 133
 134 static bool bl_map_concat(struct pnfs_block_dev *dev, u64 offset,
 135                 struct pnfs_block_dev_map *map)
 136 {
 137         int i;
 138
 139         for (i = 0; i < dev->nr_children; i++) {
 140                 struct pnfs_block_dev *child = &dev->children[i];
 141
 142                 if (child->start > offset ||
 143                     child->start + child->len <= offset)
 144                         continue;
 145
 146                 child->map(child, offset - child->start, map);
 147                 return true;
 148         }
 149
 150         dprintk("%s: ran off loop!\n", __func__);
 151         return false;
 152 }
 153
 154 static bool bl_map_stripe(struct pnfs_block_dev *dev, u64 offset,
 155                 struct pnfs_block_dev_map *map)
 156 {
 157         struct pnfs_block_dev *child;
 158         u64 chunk;
 159         u32 chunk_idx;
 160         u64 disk_offset;
 161
 162         chunk = div_u64(offset, dev->chunk_size);
 163         div_u64_rem(chunk, dev->nr_children, &chunk_idx);
 164
 165         if (chunk_idx > dev->nr_children) {
 166                 dprintk("%s: invalid chunk idx %d (%lld/%lld)\n",
 167                         __func__, chunk_idx, offset, dev->chunk_size);
 168                 /* error, should not happen */
 169                 return false;
 170         }
 171
 172         /* truncate offset to the beginning of the stripe */
 173         offset = chunk * dev->chunk_size;
 174
 175         /* disk offset of the stripe */
 176         disk_offset = div_u64(offset, dev->nr_children);
 177
 178         child = &dev->children[chunk_idx];
 179         child->map(child, disk_offset, map);
 180
 181         map->start += offset;
 182         map->disk_offset += disk_offset;
 183         map->len = dev->chunk_size;
 184         return true;
 185 }
 186
 187 static int
 188 bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
 189                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask);
 190
 191
 192 static int
 193 bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d,
 194                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
 195 {
 196         struct pnfs_block_volume *v = &volumes[idx];
 197         dev_t dev;
 198
 199         dev = bl_resolve_deviceid(server, v, gfp_mask);
 200         if (!dev)
 201                 return -EIO;
 202
 203         d->bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
 204         if (IS_ERR(d->bdev)) {
 205                 printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n",
 206                         MAJOR(dev), MINOR(dev), PTR_ERR(d->bdev));
 207                 return PTR_ERR(d->bdev);
 208         }
 209
 210
 211         d->len = i_size_read(d->bdev->bd_inode);
 212         d->map = bl_map_simple;
 213
 214         printk(KERN_INFO "pNFS: using block device %s\n",
 215                 d->bdev->bd_disk->disk_name);
 216         return 0;
 217 }
 218
 219 static int
 220 bl_parse_slice(struct nfs_server *server, struct pnfs_block_dev *d,
 221                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
 222 {
 223         struct pnfs_block_volume *v = &volumes[idx];
 224         int ret;
 225
 226         ret = bl_parse_deviceid(server, d, volumes, v->slice.volume, gfp_mask);
 227         if (ret)
 228                 return ret;
 229
 230         d->disk_offset = v->slice.start;
 231         d->len = v->slice.len;
 232         return 0;
 233 }
 234
 235 static int
 236 bl_parse_concat(struct nfs_server *server, struct pnfs_block_dev *d,
 237                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
 238 {
 239         struct pnfs_block_volume *v = &volumes[idx];
 240         u64 len = 0;
 241         int ret, i;
 242
 243         d->children = kcalloc(v->concat.volumes_count,
 244                         sizeof(struct pnfs_block_dev), GFP_KERNEL);
 245         if (!d->children)
 246                 return -ENOMEM;
 247
 248         for (i = 0; i < v->concat.volumes_count; i++) {
 249                 ret = bl_parse_deviceid(server, &d->children[i],
 250                                 volumes, v->concat.volumes[i], gfp_mask);
 251                 if (ret)
 252                         return ret;
 253
 254                 d->nr_children++;
 255                 d->children[i].start += len;
 256                 len += d->children[i].len;
 257         }
 258
 259         d->len = len;
 260         d->map = bl_map_concat;
 261         return 0;
 262 }
 263
 264 static int
 265 bl_parse_stripe(struct nfs_server *server, struct pnfs_block_dev *d,
 266                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
 267 {
 268         struct pnfs_block_volume *v = &volumes[idx];
 269         u64 len = 0;
 270         int ret, i;
 271
 272         d->children = kcalloc(v->stripe.volumes_count,
 273                         sizeof(struct pnfs_block_dev), GFP_KERNEL);
 274         if (!d->children)
 275                 return -ENOMEM;
 276
 277         for (i = 0; i < v->stripe.volumes_count; i++) {
 278                 ret = bl_parse_deviceid(server, &d->children[i],
 279                                 volumes, v->stripe.volumes[i], gfp_mask);
 280                 if (ret)
 281                         return ret;
 282
 283                 d->nr_children++;
 284                 len += d->children[i].len;
 285         }
 286
 287         d->len = len;
 288         d->chunk_size = v->stripe.chunk_size;
 289         d->map = bl_map_stripe;
 290         return 0;
 291 }
 292
 293 static int
 294 bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
 295                 struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
 296 {
 297         switch (volumes[idx].type) {
 298         case PNFS_BLOCK_VOLUME_SIMPLE:
 299                 return bl_parse_simple(server, d, volumes, idx, gfp_mask);
 300         case PNFS_BLOCK_VOLUME_SLICE:
 301                 return bl_parse_slice(server, d, volumes, idx, gfp_mask);
 302         case PNFS_BLOCK_VOLUME_CONCAT:
 303                 return bl_parse_concat(server, d, volumes, idx, gfp_mask);
 304         case PNFS_BLOCK_VOLUME_STRIPE:
 305                 return bl_parse_stripe(server, d, volumes, idx, gfp_mask);
 306         default:
 307                 dprintk("unsupported volume type: %d\n", volumes[idx].type);
 308                 return -EIO;
 309         }
 310 }
 311
 312 struct nfs4_deviceid_node *
 313 bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 314                 gfp_t gfp_mask)
 315 {
 316         struct nfs4_deviceid_node *node = NULL;
 317         struct pnfs_block_volume *volumes;
 318         struct pnfs_block_dev *top;
 319         struct xdr_stream xdr;
 320         struct xdr_buf buf;
 321         struct page *scratch;
 322         int nr_volumes, ret, i;
 323         __be32 *p;
 324
 325         scratch = alloc_page(gfp_mask);
 326         if (!scratch)
 327                 goto out;
 328
 329         xdr_init_decode_pages(&xdr, &buf, pdev->pages, pdev->pglen);
 330         xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
 331
 332         p = xdr_inline_decode(&xdr, sizeof(__be32));
 333         if (!p)
 334                 goto out_free_scratch;
 335         nr_volumes = be32_to_cpup(p++);
 336
 337         volumes = kcalloc(nr_volumes, sizeof(struct pnfs_block_volume),
 338                           gfp_mask);
 339         if (!volumes)
 340                 goto out_free_scratch;
 341
 342         for (i = 0; i < nr_volumes; i++) {
 343                 ret = nfs4_block_decode_volume(&xdr, &volumes[i]);
 344                 if (ret < 0)
 345                         goto out_free_volumes;
 346         }
 347
 348         top = kzalloc(sizeof(*top), gfp_mask);
 349         if (!top)
 350                 goto out_free_volumes;
 351
 352         ret = bl_parse_deviceid(server, top, volumes, nr_volumes - 1, gfp_mask);
 353         if (ret) {
 354                 bl_free_device(top);
 355                 kfree(top);
 356                 goto out_free_volumes;
 357         }
 358
 359         node = &top->node;
 360         nfs4_init_deviceid_node(node, server, &pdev->dev_id);
 361
 362 out_free_volumes:
 363         kfree(volumes);
 364 out_free_scratch:
 365         __free_page(scratch);
 366 out:
 367         return node;
 368 }