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        if (seg->offset & (block_size - 1)) {
  60                dprintk("pnfsd: I/O misaligned\n");
  61                goto out_layoutunavailable;
  62        }
  63
  64        /*
  65         * Some clients barf on non-zero block numbers for NONE or INVALID
  66         * layouts, so make sure to zero the whole structure.
  67         */
  68        error = -ENOMEM;
  69        bex = kzalloc(sizeof(*bex), GFP_KERNEL);
  70        if (!bex)
  71                goto out_error;
  72        args->lg_content = bex;
  73
  74        error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
  75                                            &iomap, seg->iomode != IOMODE_READ,
  76                                            &device_generation);
  77        if (error) {
  78                if (error == -ENXIO)
  79                        goto out_layoutunavailable;
  80                goto out_error;
  81        }
  82
  83        if (iomap.length < args->lg_minlength) {
  84                dprintk("pnfsd: extent smaller than minlength\n");
  85                goto out_layoutunavailable;
  86        }
  87
  88        switch (iomap.type) {
  89        case IOMAP_MAPPED:
  90                if (seg->iomode == IOMODE_READ)
  91                        bex->es = PNFS_BLOCK_READ_DATA;
  92                else
  93                        bex->es = PNFS_BLOCK_READWRITE_DATA;
  94                bex->soff = (iomap.blkno << 9);
  95                break;
  96        case IOMAP_UNWRITTEN:
  97                if (seg->iomode & IOMODE_RW) {
  98                        /*
  99                         * Crack monkey special case from section 2.3.1.
 100                         */
 101                        if (args->lg_minlength == 0) {
 102                                dprintk("pnfsd: no soup for you!\n");
 103                                goto out_layoutunavailable;
 104                        }
 105
 106                        bex->es = PNFS_BLOCK_INVALID_DATA;
 107                        bex->soff = (iomap.blkno << 9);
 108                        break;
 109                }
 110                /*FALLTHRU*/
 111        case IOMAP_HOLE:
 112                if (seg->iomode == IOMODE_READ) {
 113                        bex->es = PNFS_BLOCK_NONE_DATA;
 114                        break;
 115                }
 116                /*FALLTHRU*/
 117        case IOMAP_DELALLOC:
 118        default:
 119                WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
 120                goto out_layoutunavailable;
 121        }
 122
 123        error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
 124        if (error)
 125                goto out_error;
 126        bex->foff = iomap.offset;
 127        bex->len = iomap.length;
 128
 129        seg->offset = iomap.offset;
 130        seg->length = iomap.length;
 131
 132        dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
 133        return 0;
 134
 135out_error:
 136        seg->length = 0;
 137        return nfserrno(error);
 138out_layoutunavailable:
 139        seg->length = 0;
 140        return nfserr_layoutunavailable;
 141}
 142
 143static __be32
 144nfsd4_block_proc_layoutcommit(struct inode *inode,
 145                struct nfsd4_layoutcommit *lcp)
 146{
 147        loff_t new_size = lcp->lc_last_wr + 1;
 148        struct iattr iattr = { .ia_valid = 0 };
 149        struct iomap *iomaps;
 150        int nr_iomaps;
 151        int error;
 152
 153        nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
 154                        lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
 155        if (nr_iomaps < 0)
 156                return nfserrno(nr_iomaps);
 157
 158        if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
 159            timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
 160                lcp->lc_mtime = current_fs_time(inode->i_sb);
 161        iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
 162        iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
 163
 164        if (new_size > i_size_read(inode)) {
 165                iattr.ia_valid |= ATTR_SIZE;
 166                iattr.ia_size = new_size;
 167        }
 168
 169        error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
 170                        nr_iomaps, &iattr);
 171        kfree(iomaps);
 172        return nfserrno(error);
 173}
 174
 175const struct nfsd4_layout_ops bl_layout_ops = {
 176        /*
 177         * Pretend that we send notification to the client.  This is a blatant
 178         * lie to force recent Linux clients to cache our device IDs.
 179         * We rarely ever change the device ID, so the harm of leaking deviceids
 180         * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
 181         * in this regard, but I filed errata 4119 for this a while ago, and
 182         * hopefully the Linux client will eventually start caching deviceids
 183         * without this again.
 184         */
 185        .notify_types           =
 186                        NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
 187        .proc_getdeviceinfo     = nfsd4_block_proc_getdeviceinfo,
 188        .encode_getdeviceinfo   = nfsd4_block_encode_getdeviceinfo,
 189        .proc_layoutget         = nfsd4_block_proc_layoutget,
 190        .encode_layoutget       = nfsd4_block_encode_layoutget,
 191        .proc_layoutcommit      = nfsd4_block_proc_layoutcommit,
 192};
 193