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
  16 static int
  17 nfsd4_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
  38 static __be32
  39 nfsd4_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
  47 static __be32
  48 nfsd4_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
 143 out_error:
 144         seg->length = 0;
 145         return nfserrno(error);
 146 out_layoutunavailable:
 147         seg->length = 0;
 148         return nfserr_layoutunavailable;
 149 }
 150
 151 static __be32
 152 nfsd4_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
 183 const 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 };