Commit e9437cce authored by Fred Isaman's avatar Fred Isaman Committed by Trond Myklebust

pnfsblock: xdr decode pnfs_block_layout4

XDR decodes the block layout payload sent in LAYOUTGET result, storing
the result in an extent list.

[pnfsblock: get rid of deprecated xdr macros]
Signed-off-by: default avatarJim Rees <rees@umich.edu>
Signed-off-by: default avatarFred Isaman <iisaman@citi.umich.edu>
[pnfsblock: fix bug getting pnfs_layout_type in translate_devid().]
Signed-off-by: default avatarTao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@tonian.com>
Signed-off-by: default avatarJim Rees <rees@umich.edu>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 2f9fd182
......@@ -40,6 +40,19 @@
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
static int decode_sector_number(__be32 **rp, sector_t *sp)
{
uint64_t s;
*rp = xdr_decode_hyper(*rp, &s);
if (s & 0x1ff) {
printk(KERN_WARNING "%s: sector not aligned\n", __func__);
return -1;
}
*sp = s >> SECTOR_SHIFT;
return 0;
}
/* Open a block_device by device number. */
struct block_device *nfs4_blkdev_get(dev_t dev)
{
......@@ -197,10 +210,201 @@ nfs4_blk_decode_device(struct nfs_server *server,
return rv;
}
/* Map deviceid returned by the server to constructed block_device */
static struct block_device *translate_devid(struct pnfs_layout_hdr *lo,
struct nfs4_deviceid *id)
{
struct block_device *rv = NULL;
struct block_mount_id *mid;
struct pnfs_block_dev *dev;
dprintk("%s enter, lo=%p, id=%p\n", __func__, lo, id);
mid = BLK_ID(lo);
spin_lock(&mid->bm_lock);
list_for_each_entry(dev, &mid->bm_devlist, bm_node) {
if (memcmp(id->data, dev->bm_mdevid.data,
NFS4_DEVICEID4_SIZE) == 0) {
rv = dev->bm_mdev;
goto out;
}
}
out:
spin_unlock(&mid->bm_lock);
dprintk("%s returning %p\n", __func__, rv);
return rv;
}
/* Tracks info needed to ensure extents in layout obey constraints of spec */
struct layout_verification {
u32 mode; /* R or RW */
u64 start; /* Expected start of next non-COW extent */
u64 inval; /* Start of INVAL coverage */
u64 cowread; /* End of COW read coverage */
};
/* Verify the extent meets the layout requirements of the pnfs-block draft,
* section 2.3.1.
*/
static int verify_extent(struct pnfs_block_extent *be,
struct layout_verification *lv)
{
if (lv->mode == IOMODE_READ) {
if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
be->be_state == PNFS_BLOCK_INVALID_DATA)
return -EIO;
if (be->be_f_offset != lv->start)
return -EIO;
lv->start += be->be_length;
return 0;
}
/* lv->mode == IOMODE_RW */
if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
if (be->be_f_offset != lv->start)
return -EIO;
if (lv->cowread > lv->start)
return -EIO;
lv->start += be->be_length;
lv->inval = lv->start;
return 0;
} else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
if (be->be_f_offset != lv->start)
return -EIO;
lv->start += be->be_length;
return 0;
} else if (be->be_state == PNFS_BLOCK_READ_DATA) {
if (be->be_f_offset > lv->start)
return -EIO;
if (be->be_f_offset < lv->inval)
return -EIO;
if (be->be_f_offset < lv->cowread)
return -EIO;
/* It looks like you might want to min this with lv->start,
* but you really don't.
*/
lv->inval = lv->inval + be->be_length;
lv->cowread = be->be_f_offset + be->be_length;
return 0;
} else
return -EIO;
}
/* XDR decode pnfs_block_layout4 structure */
int
nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
struct nfs4_layoutget_res *lgr, gfp_t gfp_flags)
{
/* STUB */
return -EIO;
struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
int i, status = -EIO;
uint32_t count;
struct pnfs_block_extent *be = NULL, *save;
struct xdr_stream stream;
struct xdr_buf buf;
struct page *scratch;
__be32 *p;
struct layout_verification lv = {
.mode = lgr->range.iomode,
.start = lgr->range.offset >> SECTOR_SHIFT,
.inval = lgr->range.offset >> SECTOR_SHIFT,
.cowread = lgr->range.offset >> SECTOR_SHIFT,
};
LIST_HEAD(extents);
dprintk("---> %s\n", __func__);
scratch = alloc_page(gfp_flags);
if (!scratch)
return -ENOMEM;
xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
p = xdr_inline_decode(&stream, 4);
if (unlikely(!p))
goto out_err;
count = be32_to_cpup(p++);
dprintk("%s enter, number of extents %i\n", __func__, count);
p = xdr_inline_decode(&stream, (28 + NFS4_DEVICEID4_SIZE) * count);
if (unlikely(!p))
goto out_err;
/* Decode individual extents, putting them in temporary
* staging area until whole layout is decoded to make error
* recovery easier.
*/
for (i = 0; i < count; i++) {
be = bl_alloc_extent();
if (!be) {
status = -ENOMEM;
goto out_err;
}
memcpy(&be->be_devid, p, NFS4_DEVICEID4_SIZE);
p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
be->be_mdev = translate_devid(lo, &be->be_devid);
if (!be->be_mdev)
goto out_err;
/* The next three values are read in as bytes,
* but stored as 512-byte sector lengths
*/
if (decode_sector_number(&p, &be->be_f_offset) < 0)
goto out_err;
if (decode_sector_number(&p, &be->be_length) < 0)
goto out_err;
if (decode_sector_number(&p, &be->be_v_offset) < 0)
goto out_err;
be->be_state = be32_to_cpup(p++);
if (be->be_state == PNFS_BLOCK_INVALID_DATA)
be->be_inval = &bl->bl_inval;
if (verify_extent(be, &lv)) {
dprintk("%s verify failed\n", __func__);
goto out_err;
}
list_add_tail(&be->be_node, &extents);
}
if (lgr->range.offset + lgr->range.length !=
lv.start << SECTOR_SHIFT) {
dprintk("%s Final length mismatch\n", __func__);
be = NULL;
goto out_err;
}
if (lv.start < lv.cowread) {
dprintk("%s Final uncovered COW extent\n", __func__);
be = NULL;
goto out_err;
}
/* Extents decoded properly, now try to merge them in to
* existing layout extents.
*/
spin_lock(&bl->bl_ext_lock);
list_for_each_entry_safe(be, save, &extents, be_node) {
list_del(&be->be_node);
status = bl_add_merge_extent(bl, be);
if (status) {
spin_unlock(&bl->bl_ext_lock);
/* This is a fairly catastrophic error, as the
* entire layout extent lists are now corrupted.
* We should have some way to distinguish this.
*/
be = NULL;
goto out_err;
}
}
spin_unlock(&bl->bl_ext_lock);
status = 0;
out:
__free_page(scratch);
dprintk("%s returns %i\n", __func__, status);
return status;
out_err:
bl_put_extent(be);
while (!list_empty(&extents)) {
be = list_first_entry(&extents, struct pnfs_block_extent,
be_node);
list_del(&be->be_node);
bl_put_extent(be);
}
goto out;
}
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