dlm: move lkb idr to xarray datastructure

According to kernel doc idr is deprecated and xarrays should be used
nowadays. This patch is moving the lkb idr implementation to xarrays.

Signed-off-by: Alexander Aring <[e-mail]>
Signed-off-by: David Teigland <[e-mail]>

fs/dlm/dlm_internal.h

···
 #include <linux/rhashtable.h>
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/xarray.h>
 #include <linux/ratelimit.h>
 #include <linux/uaccess.h>
 
···
 	unsigned long		ls_flags;	/* LSFL_ */
 	struct kobject		ls_kobj;
 
-	struct idr		ls_lkbidr;
-	rwlock_t		ls_lkbidr_lock;
+	struct xarray		ls_lkbxa;
+	rwlock_t		ls_lkbxa_lock;
 
 	struct rhashtable	ls_rsbtbl;
 	rwlock_t		ls_rsbtbl_lock;

fs/dlm/lock.c

···
 }
 
 static int _create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret,
-		       int start, int end)
+		       unsigned long start, unsigned long end)
 {
+	struct xa_limit limit;
 	struct dlm_lkb *lkb;
 	int rv;
+
+	limit.max = end;
+	limit.min = start;
 
 	lkb = dlm_allocate_lkb(ls);
 	if (!lkb)
···
 	INIT_LIST_HEAD(&lkb->lkb_ownqueue);
 	INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
 
-	write_lock_bh(&ls->ls_lkbidr_lock);
-	rv = idr_alloc(&ls->ls_lkbidr, lkb, start, end, GFP_NOWAIT);
-	if (rv >= 0)
-		lkb->lkb_id = rv;
-	write_unlock_bh(&ls->ls_lkbidr_lock);
+	write_lock_bh(&ls->ls_lkbxa_lock);
+	rv = xa_alloc(&ls->ls_lkbxa, &lkb->lkb_id, lkb, limit, GFP_ATOMIC);
+	write_unlock_bh(&ls->ls_lkbxa_lock);
 
 	if (rv < 0) {
-		log_error(ls, "create_lkb idr error %d", rv);
+		log_error(ls, "create_lkb xa error %d", rv);
 		dlm_free_lkb(lkb);
 		return rv;
 	}
···
 
 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 {
-	return _create_lkb(ls, lkb_ret, 1, 0);
+	return _create_lkb(ls, lkb_ret, 1, ULONG_MAX);
 }
 
 static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
 {
 	struct dlm_lkb *lkb;
 
-	read_lock_bh(&ls->ls_lkbidr_lock);
-	lkb = idr_find(&ls->ls_lkbidr, lkid);
+	read_lock_bh(&ls->ls_lkbxa_lock);
+	lkb = xa_load(&ls->ls_lkbxa, lkid);
 	if (lkb)
 		kref_get(&lkb->lkb_ref);
-	read_unlock_bh(&ls->ls_lkbidr_lock);
+	read_unlock_bh(&ls->ls_lkbxa_lock);
 
 	*lkb_ret = lkb;
 	return lkb ? 0 : -ENOENT;
···
 	int rv;
 
 	rv = dlm_kref_put_write_lock_bh(&lkb->lkb_ref, kill_lkb,
-					&ls->ls_lkbidr_lock);
+					&ls->ls_lkbxa_lock);
 	if (rv) {
-		idr_remove(&ls->ls_lkbidr, lkid);
-		write_unlock_bh(&ls->ls_lkbidr_lock);
+		xa_erase(&ls->ls_lkbxa, lkid);
+		write_unlock_bh(&ls->ls_lkbxa_lock);
 
 		detach_lkb(lkb);
 

fs/dlm/lockspace.c

···
 	if (error)
 		goto out_lsfree;
 
-	idr_init(&ls->ls_lkbidr);
-	rwlock_init(&ls->ls_lkbidr_lock);
+	xa_init_flags(&ls->ls_lkbxa, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_BH);
+	rwlock_init(&ls->ls_lkbxa_lock);
 
 	INIT_LIST_HEAD(&ls->ls_waiters);
 	spin_lock_init(&ls->ls_waiters_lock);
···
 	ls->ls_recover_buf = kmalloc(DLM_MAX_SOCKET_BUFSIZE, GFP_NOFS);
 	if (!ls->ls_recover_buf) {
 		error = -ENOMEM;
-		goto out_lkbidr;
+		goto out_lkbxa;
 	}
 
 	ls->ls_slot = 0;
···
 	spin_unlock_bh(&lslist_lock);
 	idr_destroy(&ls->ls_recover_idr);
 	kfree(ls->ls_recover_buf);
- out_lkbidr:
-	idr_destroy(&ls->ls_lkbidr);
+ out_lkbxa:
+	xa_destroy(&ls->ls_lkbxa);
 	rhashtable_destroy(&ls->ls_rsbtbl);
  out_lsfree:
 	if (do_unreg)
···
 				   ops_arg, ops_result, lockspace);
 }
 
-static int lkb_idr_is_local(int id, void *p, void *data)
+static int lkb_idr_free(struct dlm_lkb *lkb)
 {
-	struct dlm_lkb *lkb = p;
-
-	return lkb->lkb_nodeid == 0 && lkb->lkb_grmode != DLM_LOCK_IV;
-}
-
-static int lkb_idr_is_any(int id, void *p, void *data)
-{
-	return 1;
-}
-
-static int lkb_idr_free(int id, void *p, void *data)
-{
-	struct dlm_lkb *lkb = p;
-
 	if (lkb->lkb_lvbptr && test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags))
 		dlm_free_lvb(lkb->lkb_lvbptr);
 
···
 	return 0;
 }
 
-/* NOTE: We check the lkbidr here rather than the resource table.
+/* NOTE: We check the lkbxa here rather than the resource table.
    This is because there may be LKBs queued as ASTs that have been unlinked
    from their RSBs and are pending deletion once the AST has been delivered */
 
 static int lockspace_busy(struct dlm_ls *ls, int force)
 {
-	int rv;
+	struct dlm_lkb *lkb;
+	unsigned long id;
+	int rv = 0;
 
-	read_lock_bh(&ls->ls_lkbidr_lock);
+	read_lock_bh(&ls->ls_lkbxa_lock);
 	if (force == 0) {
-		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_any, ls);
+		xa_for_each(&ls->ls_lkbxa, id, lkb) {
+			rv = 1;
+			break;
+		}
 	} else if (force == 1) {
-		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_local, ls);
+		xa_for_each(&ls->ls_lkbxa, id, lkb) {
+			if (lkb->lkb_nodeid == 0 &&
+			    lkb->lkb_grmode != DLM_LOCK_IV) {
+				rv = 1;
+				break;
+			}
+		}
 	} else {
 		rv = 0;
 	}
-	read_unlock_bh(&ls->ls_lkbidr_lock);
+	read_unlock_bh(&ls->ls_lkbxa_lock);
 	return rv;
 }
 
···
 
 static int release_lockspace(struct dlm_ls *ls, int force)
 {
+	struct dlm_lkb *lkb;
+	unsigned long id;
 	int busy, rv;
 
 	busy = lockspace_busy(ls, force);
···
 	kfree(ls->ls_recover_buf);
 
 	/*
-	 * Free all lkb's in idr
+	 * Free all lkb's in xa
 	 */
-
-	idr_for_each(&ls->ls_lkbidr, lkb_idr_free, ls);
-	idr_destroy(&ls->ls_lkbidr);
+	xa_for_each(&ls->ls_lkbxa, id, lkb) {
+		lkb_idr_free(lkb);
+	}
+	xa_destroy(&ls->ls_lkbxa);
 
 	/*
 	 * Free all rsb's on rsbtbl