list.h: new helper - hlist_add_fake()

Make node look as if it was on hlist, with hlist_del() working correctly. Usable without any locking... Convert a couple of places where we want to do that to inode->i_hash. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

list.h: new helper - hlist_add_fake()
Make node look as if it was on hlist, with hlist_del() working correctly. Usable without any locking... Convert a couple of places where we want to do that to inode->i_hash. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro
1 parent 1d3382cbf0
Showing 3 changed files with 8 additions and 2 deletions Side-by-side Diff
fs/hfsplus/inode.c
fs/jfs/jfs_imap.c
include/linux/list.h
@@ -211,7 +211,7 @@
 	 * appear hashed, but do not put on any lists.  hlist_del()
 	 * will work fine and require no locking.
 	 */
-	inode->i_hash.pprev = &inode->i_hash.next;
+	hlist_add_fake(&inode->i_hash);
  
 	mark_inode_dirty(inode);
 out:
@@ -497,7 +497,7 @@
 	 * appear hashed, but do not put on any lists.  hlist_del()
 	 * will work fine and require no locking.
 	 */
-	ip->i_hash.pprev = &ip->i_hash.next;
+	hlist_add_fake(&ip->i_hash);
  
 	return (ip);
 }
@@ -636,6 +636,12 @@
 		next->next->pprev  = &next->next;
 }
  
+/* after that we'll appear to be on some hlist and hlist_del will work */
+static inline void hlist_add_fake(struct hlist_node *n)
+{
+	n->pprev = &n->next;
+}
+
 /*
  * Move a list from one list head to another. Fixup the pprev
  * reference of the first entry if it exists.
...	...	@@ -211,7 +211,7 @@
211	211	* appear hashed, but do not put on any lists. hlist_del()
212	212	* will work fine and require no locking.
213	213	*/
214		- inode->i_hash.pprev = &inode->i_hash.next;
	214	+ hlist_add_fake(&inode->i_hash);
215	215
216	216	mark_inode_dirty(inode);
217	217	out:
...	...	@@ -497,7 +497,7 @@
497	497	* appear hashed, but do not put on any lists. hlist_del()
498	498	* will work fine and require no locking.
499	499	*/
500		- ip->i_hash.pprev = &ip->i_hash.next;
	500	+ hlist_add_fake(&ip->i_hash);
501	501
502	502	return (ip);
503	503	}
...	...	@@ -636,6 +636,12 @@
636	636	next->next->pprev = &next->next;
637	637	}
638	638
	639	+/* after that we'll appear to be on some hlist and hlist_del will work */
	640	+static inline void hlist_add_fake(struct hlist_node *n)
	641	+{
	642	+ n->pprev = &n->next;
	643	+}
	644	+
639	645	/*
640	646	* Move a list from one list head to another. Fixup the pprev
641	647	* reference of the first entry if it exists.