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