linux/fs/nfsd/blocklayout.c
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   1/*
   2 * Copyright (c) 2014-2016 Christoph Hellwig.
   3 */
   4#include <linux/exportfs.h>
   5#include <linux/genhd.h>
   6#include <linux/slab.h>
   7#include <linux/pr.h>
   8
   9#include <linux/nfsd/debug.h>
  10#include <scsi/scsi_proto.h>
  11#include <scsi/scsi_common.h>
  12
  13#include "blocklayoutxdr.h"
  14#include "pnfs.h"
  15
  16#define NFSDDBG_FACILITY        NFSDDBG_PNFS
  17
  18
  19static __be32
  20nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
  21                struct nfsd4_layoutget *args)
  22{
  23        struct nfsd4_layout_seg *seg = &args->lg_seg;
  24        struct super_block *sb = inode->i_sb;
  25        u32 block_size = (1 << inode->i_blkbits);
  26        struct pnfs_block_extent *bex;
  27        struct iomap iomap;
  28        u32 device_generation = 0;
  29        int error;
  30
  31        if (seg->offset & (block_size - 1)) {
  32                dprintk("pnfsd: I/O misaligned\n");
  33                goto out_layoutunavailable;
  34        }
  35
  36        /*
  37         * Some clients barf on non-zero block numbers for NONE or INVALID
  38         * layouts, so make sure to zero the whole structure.
  39         */
  40        error = -ENOMEM;
  41        bex = kzalloc(sizeof(*bex), GFP_KERNEL);
  42        if (!bex)
  43                goto out_error;
  44        args->lg_content = bex;
  45
  46        error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
  47                                            &iomap, seg->iomode != IOMODE_READ,
  48                                            &device_generation);
  49        if (error) {
  50                if (error == -ENXIO)
  51                        goto out_layoutunavailable;
  52                goto out_error;
  53        }
  54
  55        if (iomap.length < args->lg_minlength) {
  56                dprintk("pnfsd: extent smaller than minlength\n");
  57                goto out_layoutunavailable;
  58        }
  59
  60        switch (iomap.type) {
  61        case IOMAP_MAPPED:
  62                if (seg->iomode == IOMODE_READ)
  63                        bex->es = PNFS_BLOCK_READ_DATA;
  64                else
  65                        bex->es = PNFS_BLOCK_READWRITE_DATA;
  66                bex->soff = (iomap.blkno << 9);
  67                break;
  68        case IOMAP_UNWRITTEN:
  69                if (seg->iomode & IOMODE_RW) {
  70                        /*
  71                         * Crack monkey special case from section 2.3.1.
  72                         */
  73                        if (args->lg_minlength == 0) {
  74                                dprintk("pnfsd: no soup for you!\n");
  75                                goto out_layoutunavailable;
  76                        }
  77
  78                        bex->es = PNFS_BLOCK_INVALID_DATA;
  79                        bex->soff = (iomap.blkno << 9);
  80                        break;
  81                }
  82                /*FALLTHRU*/
  83        case IOMAP_HOLE:
  84                if (seg->iomode == IOMODE_READ) {
  85                        bex->es = PNFS_BLOCK_NONE_DATA;
  86                        break;
  87                }
  88                /*FALLTHRU*/
  89        case IOMAP_DELALLOC:
  90        default:
  91                WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
  92                goto out_layoutunavailable;
  93        }
  94
  95        error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
  96        if (error)
  97                goto out_error;
  98        bex->foff = iomap.offset;
  99        bex->len = iomap.length;
 100
 101        seg->offset = iomap.offset;
 102        seg->length = iomap.length;
 103
 104        dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
 105        return 0;
 106
 107out_error:
 108        seg->length = 0;
 109        return nfserrno(error);
 110out_layoutunavailable:
 111        seg->length = 0;
 112        return nfserr_layoutunavailable;
 113}
 114
 115static __be32
 116nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
 117                struct iomap *iomaps, int nr_iomaps)
 118{
 119        loff_t new_size = lcp->lc_last_wr + 1;
 120        struct iattr iattr = { .ia_valid = 0 };
 121        int error;
 122
 123        if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
 124            timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
 125                lcp->lc_mtime = current_fs_time(inode->i_sb);
 126        iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
 127        iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
 128
 129        if (new_size > i_size_read(inode)) {
 130                iattr.ia_valid |= ATTR_SIZE;
 131                iattr.ia_size = new_size;
 132        }
 133
 134        error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
 135                        nr_iomaps, &iattr);
 136        kfree(iomaps);
 137        return nfserrno(error);
 138}
 139
 140#ifdef CONFIG_NFSD_BLOCKLAYOUT
 141static int
 142nfsd4_block_get_device_info_simple(struct super_block *sb,
 143                struct nfsd4_getdeviceinfo *gdp)
 144{
 145        struct pnfs_block_deviceaddr *dev;
 146        struct pnfs_block_volume *b;
 147
 148        dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
 149                      sizeof(struct pnfs_block_volume), GFP_KERNEL);
 150        if (!dev)
 151                return -ENOMEM;
 152        gdp->gd_device = dev;
 153
 154        dev->nr_volumes = 1;
 155        b = &dev->volumes[0];
 156
 157        b->type = PNFS_BLOCK_VOLUME_SIMPLE;
 158        b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
 159        return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
 160                        &b->simple.offset);
 161}
 162
 163static __be32
 164nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
 165                struct nfs4_client *clp,
 166                struct nfsd4_getdeviceinfo *gdp)
 167{
 168        if (sb->s_bdev != sb->s_bdev->bd_contains)
 169                return nfserr_inval;
 170        return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
 171}
 172
 173static __be32
 174nfsd4_block_proc_layoutcommit(struct inode *inode,
 175                struct nfsd4_layoutcommit *lcp)
 176{
 177        struct iomap *iomaps;
 178        int nr_iomaps;
 179
 180        nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
 181                        lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
 182        if (nr_iomaps < 0)
 183                return nfserrno(nr_iomaps);
 184
 185        return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
 186}
 187
 188const struct nfsd4_layout_ops bl_layout_ops = {
 189        /*
 190         * Pretend that we send notification to the client.  This is a blatant
 191         * lie to force recent Linux clients to cache our device IDs.
 192         * We rarely ever change the device ID, so the harm of leaking deviceids
 193         * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
 194         * in this regard, but I filed errata 4119 for this a while ago, and
 195         * hopefully the Linux client will eventually start caching deviceids
 196         * without this again.
 197         */
 198        .notify_types           =
 199                        NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
 200        .proc_getdeviceinfo     = nfsd4_block_proc_getdeviceinfo,
 201        .encode_getdeviceinfo   = nfsd4_block_encode_getdeviceinfo,
 202        .proc_layoutget         = nfsd4_block_proc_layoutget,
 203        .encode_layoutget       = nfsd4_block_encode_layoutget,
 204        .proc_layoutcommit      = nfsd4_block_proc_layoutcommit,
 205};
 206#endif /* CONFIG_NFSD_BLOCKLAYOUT */
 207
 208#ifdef CONFIG_NFSD_SCSILAYOUT
 209static int nfsd4_scsi_identify_device(struct block_device *bdev,
 210                struct pnfs_block_volume *b)
 211{
 212        struct request_queue *q = bdev->bd_disk->queue;
 213        struct request *rq;
 214        size_t bufflen = 252, len, id_len;
 215        u8 *buf, *d, type, assoc;
 216        int error;
 217
 218        buf = kzalloc(bufflen, GFP_KERNEL);
 219        if (!buf)
 220                return -ENOMEM;
 221
 222        rq = blk_get_request(q, READ, GFP_KERNEL);
 223        if (IS_ERR(rq)) {
 224                error = -ENOMEM;
 225                goto out_free_buf;
 226        }
 227        blk_rq_set_block_pc(rq);
 228
 229        error = blk_rq_map_kern(q, rq, buf, bufflen, GFP_KERNEL);
 230        if (error)
 231                goto out_put_request;
 232
 233        rq->cmd[0] = INQUIRY;
 234        rq->cmd[1] = 1;
 235        rq->cmd[2] = 0x83;
 236        rq->cmd[3] = bufflen >> 8;
 237        rq->cmd[4] = bufflen & 0xff;
 238        rq->cmd_len = COMMAND_SIZE(INQUIRY);
 239
 240        error = blk_execute_rq(rq->q, NULL, rq, 1);
 241        if (error) {
 242                pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
 243                        rq->errors);
 244                goto out_put_request;
 245        }
 246
 247        len = (buf[2] << 8) + buf[3] + 4;
 248        if (len > bufflen) {
 249                pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
 250                        len);
 251                goto out_put_request;
 252        }
 253
 254        d = buf + 4;
 255        for (d = buf + 4; d < buf + len; d += id_len + 4) {
 256                id_len = d[3];
 257                type = d[1] & 0xf;
 258                assoc = (d[1] >> 4) & 0x3;
 259
 260                /*
 261                 * We only care about a EUI-64 and NAA designator types
 262                 * with LU association.
 263                 */
 264                if (assoc != 0x00)
 265                        continue;
 266                if (type != 0x02 && type != 0x03)
 267                        continue;
 268                if (id_len != 8 && id_len != 12 && id_len != 16)
 269                        continue;
 270
 271                b->scsi.code_set = PS_CODE_SET_BINARY;
 272                b->scsi.designator_type = type == 0x02 ?
 273                        PS_DESIGNATOR_EUI64 : PS_DESIGNATOR_NAA;
 274                b->scsi.designator_len = id_len;
 275                memcpy(b->scsi.designator, d + 4, id_len);
 276
 277                /*
 278                 * If we found a 8 or 12 byte descriptor continue on to
 279                 * see if a 16 byte one is available.  If we find a
 280                 * 16 byte descriptor we're done.
 281                 */
 282                if (id_len == 16)
 283                        break;
 284        }
 285
 286out_put_request:
 287        blk_put_request(rq);
 288out_free_buf:
 289        kfree(buf);
 290        return error;
 291}
 292
 293#define NFSD_MDS_PR_KEY         0x0100000000000000ULL
 294
 295/*
 296 * We use the client ID as a unique key for the reservations.
 297 * This allows us to easily fence a client when recalls fail.
 298 */
 299static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
 300{
 301        return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id;
 302}
 303
 304static int
 305nfsd4_block_get_device_info_scsi(struct super_block *sb,
 306                struct nfs4_client *clp,
 307                struct nfsd4_getdeviceinfo *gdp)
 308{
 309        struct pnfs_block_deviceaddr *dev;
 310        struct pnfs_block_volume *b;
 311        const struct pr_ops *ops;
 312        int error;
 313
 314        dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
 315                      sizeof(struct pnfs_block_volume), GFP_KERNEL);
 316        if (!dev)
 317                return -ENOMEM;
 318        gdp->gd_device = dev;
 319
 320        dev->nr_volumes = 1;
 321        b = &dev->volumes[0];
 322
 323        b->type = PNFS_BLOCK_VOLUME_SCSI;
 324        b->scsi.pr_key = nfsd4_scsi_pr_key(clp);
 325
 326        error = nfsd4_scsi_identify_device(sb->s_bdev, b);
 327        if (error)
 328                return error;
 329
 330        ops = sb->s_bdev->bd_disk->fops->pr_ops;
 331        if (!ops) {
 332                pr_err("pNFS: device %s does not support PRs.\n",
 333                        sb->s_id);
 334                return -EINVAL;
 335        }
 336
 337        error = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
 338        if (error) {
 339                pr_err("pNFS: failed to register key for device %s.\n",
 340                        sb->s_id);
 341                return -EINVAL;
 342        }
 343
 344        error = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
 345                        PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
 346        if (error) {
 347                pr_err("pNFS: failed to reserve device %s.\n",
 348                        sb->s_id);
 349                return -EINVAL;
 350        }
 351
 352        return 0;
 353}
 354
 355static __be32
 356nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
 357                struct nfs4_client *clp,
 358                struct nfsd4_getdeviceinfo *gdp)
 359{
 360        if (sb->s_bdev != sb->s_bdev->bd_contains)
 361                return nfserr_inval;
 362        return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
 363}
 364static __be32
 365nfsd4_scsi_proc_layoutcommit(struct inode *inode,
 366                struct nfsd4_layoutcommit *lcp)
 367{
 368        struct iomap *iomaps;
 369        int nr_iomaps;
 370
 371        nr_iomaps = nfsd4_scsi_decode_layoutupdate(lcp->lc_up_layout,
 372                        lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
 373        if (nr_iomaps < 0)
 374                return nfserrno(nr_iomaps);
 375
 376        return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
 377}
 378
 379static void
 380nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
 381{
 382        struct nfs4_client *clp = ls->ls_stid.sc_client;
 383        struct block_device *bdev = ls->ls_file->f_path.mnt->mnt_sb->s_bdev;
 384
 385        bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
 386                        nfsd4_scsi_pr_key(clp), 0, true);
 387}
 388
 389const struct nfsd4_layout_ops scsi_layout_ops = {
 390        /*
 391         * Pretend that we send notification to the client.  This is a blatant
 392         * lie to force recent Linux clients to cache our device IDs.
 393         * We rarely ever change the device ID, so the harm of leaking deviceids
 394         * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
 395         * in this regard, but I filed errata 4119 for this a while ago, and
 396         * hopefully the Linux client will eventually start caching deviceids
 397         * without this again.
 398         */
 399        .notify_types           =
 400                        NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
 401        .proc_getdeviceinfo     = nfsd4_scsi_proc_getdeviceinfo,
 402        .encode_getdeviceinfo   = nfsd4_block_encode_getdeviceinfo,
 403        .proc_layoutget         = nfsd4_block_proc_layoutget,
 404        .encode_layoutget       = nfsd4_block_encode_layoutget,
 405        .proc_layoutcommit      = nfsd4_scsi_proc_layoutcommit,
 406        .fence_client           = nfsd4_scsi_fence_client,
 407};
 408#endif /* CONFIG_NFSD_SCSILAYOUT */
 409