LXR linux/fs/nfsd/blocklayout.c

   1/*
   2 * Copyright (c) 2014 Christoph Hellwig.
   3 */
   4#include <linux/exportfs.h>
   5#include <linux/genhd.h>
   6#include <linux/slab.h>
   7
   8#include <linux/nfsd/debug.h>
   9
  10#include "blocklayoutxdr.h"
  11#include "pnfs.h"
  12
  13#define NFSDDBG_FACILITY        NFSDDBG_PNFS
  14
  15
  16static int
  17nfsd4_block_get_device_info_simple(struct super_block *sb,
  18                struct nfsd4_getdeviceinfo *gdp)
  19{
  20        struct pnfs_block_deviceaddr *dev;
  21        struct pnfs_block_volume *b;
  22
  23        dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
  24                      sizeof(struct pnfs_block_volume), GFP_KERNEL);
  25        if (!dev)
  26                return -ENOMEM;
  27        gdp->gd_device = dev;
  28
  29        dev->nr_volumes = 1;
  30        b = &dev->volumes[0];
  31
  32        b->type = PNFS_BLOCK_VOLUME_SIMPLE;
  33        b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
  34        return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
  35                        &b->simple.offset);
  36}
  37
  38static __be32
  39nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
  40                struct nfsd4_getdeviceinfo *gdp)
  41{
  42        if (sb->s_bdev != sb->s_bdev->bd_contains)
  43                return nfserr_inval;
  44        return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
  45}
  46
  47static __be32
  48nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
  49                struct nfsd4_layoutget *args)
  50{
  51        struct nfsd4_layout_seg *seg = &args->lg_seg;
  52        struct super_block *sb = inode->i_sb;
  53        u32 block_size = (1 << inode->i_blkbits);
  54        struct pnfs_block_extent *bex;
  55        struct iomap iomap;
  56        u32 device_generation = 0;
  57        int error;
  58
  59        /*
  60         * We do not attempt to support I/O smaller than the fs block size,
  61         * or not aligned to it.
  62         */
  63        if (args->lg_minlength < block_size) {
  64                dprintk("pnfsd: I/O too small\n");
  65                goto out_layoutunavailable;
  66        }
  67        if (seg->offset & (block_size - 1)) {
  68                dprintk("pnfsd: I/O misaligned\n");
  69                goto out_layoutunavailable;
  70        }
  71
  72        /*
  73         * Some clients barf on non-zero block numbers for NONE or INVALID
  74         * layouts, so make sure to zero the whole structure.
  75         */
  76        error = -ENOMEM;
  77        bex = kzalloc(sizeof(*bex), GFP_KERNEL);
  78        if (!bex)
  79                goto out_error;
  80        args->lg_content = bex;
  81
  82        error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
  83                                            &iomap, seg->iomode != IOMODE_READ,
  84                                            &device_generation);
  85        if (error) {
  86                if (error == -ENXIO)
  87                        goto out_layoutunavailable;
  88                goto out_error;
  89        }
  90
  91        if (iomap.length < args->lg_minlength) {
  92                dprintk("pnfsd: extent smaller than minlength\n");
  93                goto out_layoutunavailable;
  94        }
  95
  96        switch (iomap.type) {
  97        case IOMAP_MAPPED:
  98                if (seg->iomode == IOMODE_READ)
  99                        bex->es = PNFS_BLOCK_READ_DATA;
 100                else
 101                        bex->es = PNFS_BLOCK_READWRITE_DATA;
 102                bex->soff = (iomap.blkno << 9);
 103                break;
 104        case IOMAP_UNWRITTEN:
 105                if (seg->iomode & IOMODE_RW) {
 106                        /*
 107                         * Crack monkey special case from section 2.3.1.
 108                         */
 109                        if (args->lg_minlength == 0) {
 110                                dprintk("pnfsd: no soup for you!\n");
 111                                goto out_layoutunavailable;
 112                        }
 113
 114                        bex->es = PNFS_BLOCK_INVALID_DATA;
 115                        bex->soff = (iomap.blkno << 9);
 116                        break;
 117                }
 118                /*FALLTHRU*/
 119        case IOMAP_HOLE:
 120                if (seg->iomode == IOMODE_READ) {
 121                        bex->es = PNFS_BLOCK_NONE_DATA;
 122                        break;
 123                }
 124                /*FALLTHRU*/
 125        case IOMAP_DELALLOC:
 126        default:
 127                WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
 128                goto out_layoutunavailable;
 129        }
 130
 131        error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
 132        if (error)
 133                goto out_error;
 134        bex->foff = iomap.offset;
 135        bex->len = iomap.length;
 136
 137        seg->offset = iomap.offset;
 138        seg->length = iomap.length;
 139
 140        dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
 141        return 0;
 142
 143out_error:
 144        seg->length = 0;
 145        return nfserrno(error);
 146out_layoutunavailable:
 147        seg->length = 0;
 148        return nfserr_layoutunavailable;
 149}
 150
 151static __be32
 152nfsd4_block_proc_layoutcommit(struct inode *inode,
 153                struct nfsd4_layoutcommit *lcp)
 154{
 155        loff_t new_size = lcp->lc_last_wr + 1;
 156        struct iattr iattr = { .ia_valid = 0 };
 157        struct iomap *iomaps;
 158        int nr_iomaps;
 159        int error;
 160
 161        nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
 162                        lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
 163        if (nr_iomaps < 0)
 164                return nfserrno(nr_iomaps);
 165
 166        if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
 167            timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
 168                lcp->lc_mtime = current_fs_time(inode->i_sb);
 169        iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
 170        iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
 171
 172        if (new_size > i_size_read(inode)) {
 173                iattr.ia_valid |= ATTR_SIZE;
 174                iattr.ia_size = new_size;
 175        }
 176
 177        error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
 178                        nr_iomaps, &iattr);
 179        kfree(iomaps);
 180        return nfserrno(error);
 181}
 182
 183const struct nfsd4_layout_ops bl_layout_ops = {
 184        /*
 185         * Pretend that we send notification to the client.  This is a blatant
 186         * lie to force recent Linux clients to cache our device IDs.
 187         * We rarely ever change the device ID, so the harm of leaking deviceids
 188         * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
 189         * in this regard, but I filed errata 4119 for this a while ago, and
 190         * hopefully the Linux client will eventually start caching deviceids
 191         * without this again.
 192         */
 193        .notify_types           =
 194                        NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
 195        .proc_getdeviceinfo     = nfsd4_block_proc_getdeviceinfo,
 196        .encode_getdeviceinfo   = nfsd4_block_encode_getdeviceinfo,
 197        .proc_layoutget         = nfsd4_block_proc_layoutget,
 198        .encode_layoutget       = nfsd4_block_encode_layoutget,
 199        .proc_layoutcommit      = nfsd4_block_proc_layoutcommit,
 200};
 201