diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index e4f99ef..4c33e19 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -99,7 +99,7 @@
 	u64 len = 1, olen;
 	u64 tmp;
 	struct ceph_object_layout ol;
-	union ceph_pg pgid;
+	struct ceph_pg pgid;
 
 	/* copy and validate */
 	if (copy_from_user(&dl, arg, sizeof(dl)))
@@ -121,7 +121,7 @@
 	ceph_calc_object_layout(&ol, dl.object_name, &ci->i_layout,
 				osdc->osdmap);
 
-	pgid.pg64 = le64_to_cpu(ol.ol_pgid);
+	pgid = ol.ol_pgid;
 	dl.osd = ceph_calc_pg_primary(osdc->osdmap, pgid);
 	if (dl.osd >= 0) {
 		struct ceph_entity_addr *a =
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index 7dc0f62..7db14ba 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -520,7 +520,7 @@
 		      struct ceph_osd_request *req)
 {
 	struct ceph_osd_request_head *reqhead = req->r_request->front.iov_base;
-	union ceph_pg pgid;
+	struct ceph_pg pgid;
 	int o = -1;
 	int err;
 	struct ceph_osd *newosd = NULL;
@@ -530,7 +530,7 @@
 				      &req->r_file_layout, osdc->osdmap);
 	if (err)
 		return err;
-	pgid.pg64 = le64_to_cpu(reqhead->layout.ol_pgid);
+	pgid = reqhead->layout.ol_pgid;
 	o = ceph_calc_pg_primary(osdc->osdmap, pgid);
 
 	if ((req->r_osd && req->r_osd->o_osd == o &&
@@ -538,8 +538,8 @@
 	    (req->r_osd == NULL && o == -1))
 		return 0;  /* no change */
 
-	dout("map_osds tid %llu pgid %llx pool %d osd%d (was osd%d)\n",
-	     req->r_tid, pgid.pg64, pgid.pg.pool, o,
+	dout("map_osds tid %llu pgid %d.%x osd%d (was osd%d)\n",
+	     req->r_tid, le32_to_cpu(pgid.pool), le16_to_cpu(pgid.ps), o,
 	     req->r_osd ? req->r_osd->o_osd : -1);
 
 	if (req->r_osd) {
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index cd7bb26..8b0cd11 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -366,19 +366,33 @@
 /*
  * Insert a new pg_temp mapping
  */
+static int pgid_cmp(struct ceph_pg l, struct ceph_pg r)
+{
+	u64 a = *(u64 *)&l;
+	u64 b = *(u64 *)&r;
+
+	if (a < b)
+		return -1;
+	if (a > b)
+		return 1;
+	return 0;
+}
+
 static int __insert_pg_mapping(struct ceph_pg_mapping *new,
 			       struct rb_root *root)
 {
 	struct rb_node **p = &root->rb_node;
 	struct rb_node *parent = NULL;
 	struct ceph_pg_mapping *pg = NULL;
+	int c;
 
 	while (*p) {
 		parent = *p;
 		pg = rb_entry(parent, struct ceph_pg_mapping, node);
-		if (new->pgid < pg->pgid)
+		c = pgid_cmp(new->pgid, pg->pgid);
+		if (c < 0)
 			p = &(*p)->rb_left;
-		else if (new->pgid > pg->pgid)
+		else if (c > 0)
 			p = &(*p)->rb_right;
 		else
 			return -EEXIST;
@@ -467,11 +481,11 @@
 	ceph_decode_32_safe(p, end, len, bad);
 	for (i = 0; i < len; i++) {
 		int n, j;
-		u64 pgid;
+		struct ceph_pg pgid;
 		struct ceph_pg_mapping *pg;
 
 		ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad);
-		pgid = ceph_decode_64(p);
+		ceph_decode_copy(p, &pgid, sizeof(pgid));
 		n = ceph_decode_32(p);
 		ceph_decode_need(p, end, n * sizeof(u32), bad);
 		pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS);
@@ -487,7 +501,7 @@
 		err = __insert_pg_mapping(pg, &map->pg_temp);
 		if (err)
 			goto bad;
-		dout(" added pg_temp %llx len %d\n", pgid, len);
+		dout(" added pg_temp %llx len %d\n", *(u64 *)&pgid, len);
 	}
 
 	/* crush */
@@ -659,19 +673,20 @@
 	while (len--) {
 		struct ceph_pg_mapping *pg;
 		int j;
-		u64 pgid;
+		struct ceph_pg pgid;
 		u32 pglen;
 		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
-		pgid = ceph_decode_64(p);
+		ceph_decode_copy(p, &pgid, sizeof(pgid));
 		pglen = ceph_decode_32(p);
 
 		/* remove any? */
-		while (rbp && rb_entry(rbp, struct ceph_pg_mapping,
-				       node)->pgid <= pgid) {
+		while (rbp && pgid_cmp(rb_entry(rbp, struct ceph_pg_mapping,
+						node)->pgid, pgid) <= 0) {
 			struct rb_node *cur = rbp;
 			rbp = rb_next(rbp);
 			dout(" removed pg_temp %llx\n",
-			     rb_entry(cur, struct ceph_pg_mapping, node)->pgid);
+			     *(u64 *)&rb_entry(cur, struct ceph_pg_mapping,
+					       node)->pgid);
 			rb_erase(cur, &map->pg_temp);
 		}
 
@@ -690,14 +705,16 @@
 			err = __insert_pg_mapping(pg, &map->pg_temp);
 			if (err)
 				goto bad;
-			dout(" added pg_temp %llx len %d\n", pgid, pglen);
+			dout(" added pg_temp %llx len %d\n", *(u64 *)&pgid,
+			     pglen);
 		}
 	}
 	while (rbp) {
 		struct rb_node *cur = rbp;
 		rbp = rb_next(rbp);
 		dout(" removed pg_temp %llx\n",
-		     rb_entry(cur, struct ceph_pg_mapping, node)->pgid);
+		     *(u64 *)&rb_entry(cur, struct ceph_pg_mapping,
+				       node)->pgid);
 		rb_erase(cur, &map->pg_temp);
 	}
 
@@ -782,16 +799,19 @@
 			    struct ceph_osdmap *osdmap)
 {
 	unsigned num, num_mask;
-	union ceph_pg pgid;
+	struct ceph_pg pgid;
 	s32 preferred = (s32)le32_to_cpu(fl->fl_pg_preferred);
 	int poolid = le32_to_cpu(fl->fl_pg_pool);
 	struct ceph_pg_pool_info *pool;
+	unsigned ps;
 
 	if (poolid >= osdmap->num_pools)
 		return -EIO;
-	pool = &osdmap->pg_pool[poolid];
 
+	pool = &osdmap->pg_pool[poolid];
+	ps = ceph_full_name_hash(oid, strlen(oid));
 	if (preferred >= 0) {
+		ps += preferred;
 		num = le32_to_cpu(pool->v.lpg_num);
 		num_mask = pool->lpg_num_mask;
 	} else {
@@ -799,22 +819,17 @@
 		num_mask = pool->pg_num_mask;
 	}
 
-	pgid.pg64 = 0;   /* start with it zeroed out */
-	pgid.pg.ps = ceph_full_name_hash(oid, strlen(oid));
-	pgid.pg.preferred = preferred;
+	pgid.ps = cpu_to_le16(ps);
+	pgid.preferred = cpu_to_le16(preferred);
+	pgid.pool = fl->fl_pg_pool;
 	if (preferred >= 0)
-		pgid.pg.ps += preferred;
-	pgid.pg.pool = le32_to_cpu(fl->fl_pg_pool);
-	if (preferred >= 0)
-		dout("calc_object_layout '%s' pgid %d.%xp%d (%llx)\n", oid,
-		     pgid.pg.pool, pgid.pg.ps, (int)preferred, pgid.pg64);
+		dout("calc_object_layout '%s' pgid %d.%xp%d\n", oid, poolid, ps,
+		     (int)preferred);
 	else
-		dout("calc_object_layout '%s' pgid %d.%x (%llx)\n", oid,
-		     pgid.pg.pool, pgid.pg.ps, pgid.pg64);
+		dout("calc_object_layout '%s' pgid %d.%x\n", oid, poolid, ps);
 
-	ol->ol_pgid = cpu_to_le64(pgid.pg64);
+	ol->ol_pgid = pgid;
 	ol->ol_stripe_unit = fl->fl_object_stripe_unit;
-
 	return 0;
 }
 
@@ -822,21 +837,24 @@
  * Calculate raw osd vector for the given pgid.  Return pointer to osd
  * array, or NULL on failure.
  */
-static int *calc_pg_raw(struct ceph_osdmap *osdmap, union ceph_pg pgid,
+static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
 			int *osds, int *num)
 {
 	struct rb_node *n = osdmap->pg_temp.rb_node;
 	struct ceph_pg_mapping *pg;
 	struct ceph_pg_pool_info *pool;
 	int ruleno;
-	unsigned pps; /* placement ps */
+	unsigned poolid, ps, pps;
+	int preferred;
+	int c;
 
 	/* pg_temp? */
 	while (n) {
 		pg = rb_entry(n, struct ceph_pg_mapping, node);
-		if (pgid.pg64 < pg->pgid)
+		c = pgid_cmp(pgid, pg->pgid);
+		if (c < 0)
 			n = n->rb_left;
-		else if (pgid.pg64 > pg->pgid)
+		else if (c > 0)
 			n = n->rb_right;
 		else {
 			*num = pg->len;
@@ -845,36 +863,40 @@
 	}
 
 	/* crush */
-	if (pgid.pg.pool >= osdmap->num_pools)
+	poolid = le32_to_cpu(pgid.pool);
+	ps = le16_to_cpu(pgid.ps);
+	preferred = (s16)le16_to_cpu(pgid.preferred);
+
+	if (poolid >= osdmap->num_pools)
 		return NULL;
-	pool = &osdmap->pg_pool[pgid.pg.pool];
+	pool = &osdmap->pg_pool[poolid];
 	ruleno = crush_find_rule(osdmap->crush, pool->v.crush_ruleset,
 				 pool->v.type, pool->v.size);
 	if (ruleno < 0) {
 		pr_err("no crush rule pool %d type %d size %d\n",
-		       pgid.pg.pool, pool->v.type, pool->v.size);
+		       poolid, pool->v.type, pool->v.size);
 		return NULL;
 	}
 
-	if (pgid.pg.preferred >= 0)
-		pps = ceph_stable_mod(pgid.pg.ps,
+	if (preferred >= 0)
+		pps = ceph_stable_mod(ps,
 				      le32_to_cpu(pool->v.lpgp_num),
 				      pool->lpgp_num_mask);
 	else
-		pps = ceph_stable_mod(pgid.pg.ps,
+		pps = ceph_stable_mod(ps,
 				      le32_to_cpu(pool->v.pgp_num),
 				      pool->pgp_num_mask);
-	pps += pgid.pg.pool;
+	pps += poolid;
 	*num = crush_do_rule(osdmap->crush, ruleno, pps, osds,
 			     min_t(int, pool->v.size, *num),
-			     pgid.pg.preferred, osdmap->osd_weight);
+			     preferred, osdmap->osd_weight);
 	return osds;
 }
 
 /*
  * Return primary osd for given pgid, or -1 if none.
  */
-int ceph_calc_pg_primary(struct ceph_osdmap *osdmap, union ceph_pg pgid)
+int ceph_calc_pg_primary(struct ceph_osdmap *osdmap, struct ceph_pg pgid)
 {
 	int rawosds[10], *osds;
 	int i, num = ARRAY_SIZE(rawosds);
diff --git a/fs/ceph/osdmap.h b/fs/ceph/osdmap.h
index 07127c6..c4af841 100644
--- a/fs/ceph/osdmap.h
+++ b/fs/ceph/osdmap.h
@@ -25,7 +25,7 @@
 
 struct ceph_pg_mapping {
 	struct rb_node node;
-	u64 pgid;
+	struct ceph_pg pgid;
 	int len;
 	int osds[];
 };
@@ -118,6 +118,7 @@
 				   const char *oid,
 				   struct ceph_file_layout *fl,
 				   struct ceph_osdmap *osdmap);
-extern int ceph_calc_pg_primary(struct ceph_osdmap *osdmap, union ceph_pg pgid);
+extern int ceph_calc_pg_primary(struct ceph_osdmap *osdmap,
+				struct ceph_pg pgid);
 
 #endif
diff --git a/fs/ceph/rados.h b/fs/ceph/rados.h
index a48cf4a..85bdef7 100644
--- a/fs/ceph/rados.h
+++ b/fs/ceph/rados.h
@@ -55,13 +55,10 @@
  * placement group.
  * we encode this into one __le64.
  */
-union ceph_pg {
-	__u64 pg64;
-	struct {
-		__s16 preferred; /* preferred primary osd */
-		__u16 ps;        /* placement seed */
-		__u32 pool;      /* object pool */
-	} __attribute__ ((packed)) pg;
+struct ceph_pg {
+	__le16 preferred; /* preferred primary osd */
+	__le16 ps;        /* placement seed */
+	__le32 pool;      /* object pool */
 } __attribute__ ((packed));
 
 /*
@@ -117,7 +114,7 @@
  * object layout - how a given object should be stored.
  */
 struct ceph_object_layout {
-	__le64 ol_pgid;           /* raw pg, with _full_ ps precision. */
+	struct ceph_pg ol_pgid;   /* raw pg, with _full_ ps precision. */
 	__le32 ol_stripe_unit;    /* for per-object parity, if any */
 } __attribute__ ((packed));