Merge tag 'ceph-for-5.1-rc1' of git://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
 "The highlights are:

   - rbd will now ignore discards that aren't aligned and big enough to
     actually free up some space (myself). This is controlled by the new
     alloc_size map option and can be disabled if needed.

   - support for rbd deep-flatten feature (myself). Deep-flatten allows
     "rbd flatten" to fully disconnect the clone image and its snapshots
     from the parent and make the parent snapshot removable.

   - a new round of cap handling improvements (Zheng Yan). The kernel
     client should now be much more prompt about releasing its caps and
     it is possible to put a limit on the number of caps held.

   - support for getting ceph.dir.pin extended attribute (Zheng Yan)"

* tag 'ceph-for-5.1-rc1' of git://github.com/ceph/ceph-client: (26 commits)
  Documentation: modern versions of ceph are not backed by btrfs
  rbd: advertise support for RBD_FEATURE_DEEP_FLATTEN
  rbd: whole-object write and zeroout should copyup when snapshots exist
  rbd: copyup with an empty snapshot context (aka deep-copyup)
  rbd: introduce rbd_obj_issue_copyup_ops()
  rbd: stop copying num_osd_ops in rbd_obj_issue_copyup()
  rbd: factor out __rbd_osd_req_create()
  rbd: clear ->xferred on error from rbd_obj_issue_copyup()
  rbd: remove experimental designation from kernel layering
  ceph: add mount option to limit caps count
  ceph: periodically trim stale dentries
  ceph: delete stale dentry when last reference is dropped
  ceph: remove dentry_lru file from debugfs
  ceph: touch existing cap when handling reply
  ceph: pass inclusive lend parameter to filemap_write_and_wait_range()
  rbd: round off and ignore discards that are too small
  rbd: handle DISCARD and WRITE_ZEROES separately
  rbd: get rid of obj_req->obj_request_count
  libceph: use struct_size() for kmalloc() in crush_decode()
  ceph: send cap releases more aggressively
  ...

net/ceph/osdmap.c

@@ -495,9 +495,8 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
 			  / sizeof(struct crush_rule_step))
 			goto bad;
 #endif
-		r = c->rules[i] = kmalloc(sizeof(*r) +
-					  yes*sizeof(struct crush_rule_step),
-					  GFP_NOFS);
+		r = kmalloc(struct_size(r, steps, yes), GFP_NOFS);
+		c->rules[i] = r;
 		if (r == NULL)
 			goto badmem;
 		dout(" rule %d is at %p\n", i, r);