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authorFred Isaman <iisaman@citi.umich.edu>2011-07-30 20:52:47 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-07-31 12:18:16 -0400
commite9437ccef92a28ba4c9009404bb8c9b5672dc54a (patch)
treee14c1076b32c7d1ce4ba19c98beade79a74ac818 /fs/nfs/blocklayout/blocklayoutdev.c
parent2f9fd182607e7b3bdca35f6ed7f2fae539f7c46b (diff)
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: Jim Rees <rees@umich.edu> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> [pnfsblock: fix bug getting pnfs_layout_type in translate_devid().] Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Benny Halevy <bhalevy@tonian.com> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/blocklayout/blocklayoutdev.c')
-rw-r--r--fs/nfs/blocklayout/blocklayoutdev.c208
1 files changed, 206 insertions, 2 deletions
diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c
index b23fe601d1c9..a83b393fb01c 100644
--- a/fs/nfs/blocklayout/blocklayoutdev.c
+++ b/fs/nfs/blocklayout/blocklayoutdev.c
@@ -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 @@ out:
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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