libceph: use ceph_kvmalloc() for osdmap arrays

osdmap has a bunch of arrays that grow linearly with the number of
OSDs.  osd_state, osd_weight and osd_primary_affinity take 4 bytes per
OSD.  osd_addr takes 136 bytes per OSD because of sockaddr_storage.
The CRUSH workspace area also grows linearly with the number of OSDs.

Normally these arrays are allocated at client startup.  The osdmap is
usually updated in small incrementals, but once in a while a full map
may need to be processed.  For a cluster with 10000 OSDs, this means
a bunch of 40K allocations followed by a 1.3M allocation, all of which
are currently required to be physically contiguous.  This results in
sporadic ENOMEM errors, hanging the client.

Go back to manually (re)allocating arrays and use ceph_kvmalloc() to
fall back to non-contiguous allocation when necessary.

Link: https://tracker.ceph.com/issues/40481
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

net/ceph/osdmap.c

@@ -973,11 +973,11 @@ void ceph_osdmap_destroy(struct ceph_osdmap *map)
 				 struct ceph_pg_pool_info, node);
 		__remove_pg_pool(&map->pg_pools, pi);
 	}
-	kfree(map->osd_state);
-	kfree(map->osd_weight);
-	kfree(map->osd_addr);
-	kfree(map->osd_primary_affinity);
-	kfree(map->crush_workspace);
+	kvfree(map->osd_state);
+	kvfree(map->osd_weight);
+	kvfree(map->osd_addr);
+	kvfree(map->osd_primary_affinity);
+	kvfree(map->crush_workspace);
 	kfree(map);
 }
 
@@ -986,28 +986,41 @@ void ceph_osdmap_destroy(struct ceph_osdmap *map)
  *
  * The new elements are properly initialized.
  */
-static int osdmap_set_max_osd(struct ceph_osdmap *map, int max)
+static int osdmap_set_max_osd(struct ceph_osdmap *map, u32 max)
 {
 	u32 *state;
 	u32 *weight;
 	struct ceph_entity_addr *addr;
+	u32 to_copy;
 	int i;
 
-	state = krealloc(map->osd_state, max*sizeof(*state), GFP_NOFS);
-	if (!state)
-		return -ENOMEM;
-	map->osd_state = state;
+	dout("%s old %u new %u\n", __func__, map->max_osd, max);
+	if (max == map->max_osd)
+		return 0;
 
-	weight = krealloc(map->osd_weight, max*sizeof(*weight), GFP_NOFS);
-	if (!weight)
+	state = ceph_kvmalloc(array_size(max, sizeof(*state)), GFP_NOFS);
+	weight = ceph_kvmalloc(array_size(max, sizeof(*weight)), GFP_NOFS);
+	addr = ceph_kvmalloc(array_size(max, sizeof(*addr)), GFP_NOFS);
+	if (!state || !weight || !addr) {
+		kvfree(state);
+		kvfree(weight);
+		kvfree(addr);
 		return -ENOMEM;
-	map->osd_weight = weight;
+	}
 
-	addr = krealloc(map->osd_addr, max*sizeof(*addr), GFP_NOFS);
-	if (!addr)
-		return -ENOMEM;
-	map->osd_addr = addr;
+	to_copy = min(map->max_osd, max);
+	if (map->osd_state) {
+		memcpy(state, map->osd_state, to_copy * sizeof(*state));
+		memcpy(weight, map->osd_weight, to_copy * sizeof(*weight));
+		memcpy(addr, map->osd_addr, to_copy * sizeof(*addr));
+		kvfree(map->osd_state);
+		kvfree(map->osd_weight);
+		kvfree(map->osd_addr);
+	}
 
+	map->osd_state = state;
+	map->osd_weight = weight;
+	map->osd_addr = addr;
 	for (i = map->max_osd; i < max; i++) {
 		map->osd_state[i] = 0;
 		map->osd_weight[i] = CEPH_OSD_OUT;
@@ -1017,12 +1030,16 @@ static int osdmap_set_max_osd(struct ceph_osdmap *map, int max)
 	if (map->osd_primary_affinity) {
 		u32 *affinity;
 
-		affinity = krealloc(map->osd_primary_affinity,
-				    max*sizeof(*affinity), GFP_NOFS);
+		affinity = ceph_kvmalloc(array_size(max, sizeof(*affinity)),
+					 GFP_NOFS);
 		if (!affinity)
 			return -ENOMEM;
-		map->osd_primary_affinity = affinity;
 
+		memcpy(affinity, map->osd_primary_affinity,
+		       to_copy * sizeof(*affinity));
+		kvfree(map->osd_primary_affinity);
+
+		map->osd_primary_affinity = affinity;
 		for (i = map->max_osd; i < max; i++)
 			map->osd_primary_affinity[i] =
 			    CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
@@ -1043,7 +1060,7 @@ static int osdmap_set_crush(struct ceph_osdmap *map, struct crush_map *crush)
 
 	work_size = crush_work_size(crush, CEPH_PG_MAX_SIZE);
 	dout("%s work_size %zu bytes\n", __func__, work_size);
-	workspace = kmalloc(work_size, GFP_NOIO);
+	workspace = ceph_kvmalloc(work_size, GFP_NOIO);
 	if (!workspace) {
 		crush_destroy(crush);
 		return -ENOMEM;
@@ -1052,7 +1069,7 @@ static int osdmap_set_crush(struct ceph_osdmap *map, struct crush_map *crush)
 
 	if (map->crush)
 		crush_destroy(map->crush);
-	kfree(map->crush_workspace);
+	kvfree(map->crush_workspace);
 	map->crush = crush;
 	map->crush_workspace = workspace;
 	return 0;
@@ -1298,9 +1315,9 @@ static int set_primary_affinity(struct ceph_osdmap *map, int osd, u32 aff)
 	if (!map->osd_primary_affinity) {
 		int i;
 
-		map->osd_primary_affinity = kmalloc_array(map->max_osd,
-							  sizeof(u32),
-							  GFP_NOFS);
+		map->osd_primary_affinity = ceph_kvmalloc(
+		    array_size(map->max_osd, sizeof(*map->osd_primary_affinity)),
+		    GFP_NOFS);
 		if (!map->osd_primary_affinity)
 			return -ENOMEM;
 
@@ -1321,7 +1338,7 @@ static int decode_primary_affinity(void **p, void *end,
 
 	ceph_decode_32_safe(p, end, len, e_inval);
 	if (len == 0) {
-		kfree(map->osd_primary_affinity);
+		kvfree(map->osd_primary_affinity);
 		map->osd_primary_affinity = NULL;
 		return 0;
 	}