[JFFS2] Fix inode allocation race

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

fs/jffs2/README.Locking

-	$Id: README.Locking,v 1.9 2004/11/20 10:35:40 dwmw2 Exp $
+	$Id: README.Locking,v 1.12 2005/04/13 13:22:35 dwmw2 Exp $
 
 	JFFS2 LOCKING DOCUMENTATION
 	---------------------------
@@ -108,6 +108,10 @@ in-core jffs2_inode_cache objects (each inode in JFFS2 has the
 correspondent jffs2_inode_cache object). So, the inocache_lock
 has to be locked while walking the c->inocache_list hash buckets.
 
+This spinlock also covers allocation of new inode numbers, which is
+currently just '++->highest_ino++', but might one day get more complicated
+if we need to deal with wrapping after 4 milliard inode numbers are used.
+
 Note, the f->sem guarantees that the correspondent jffs2_inode_cache
 will not be removed. So, it is allowed to access it without locking
 the inocache_lock spinlock. 

fs/jffs2/nodelist.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: nodelist.c,v 1.93 2005/02/27 23:01:32 dwmw2 Exp $
+ * $Id: nodelist.c,v 1.94 2005/04/13 13:22:35 dwmw2 Exp $
  *
  */
 
@@ -491,6 +491,10 @@ void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new
 	struct jffs2_inode_cache **prev;
 	D2(printk(KERN_DEBUG "jffs2_add_ino_cache: Add %p (ino #%u)\n", new, new->ino));
 	spin_lock(&c->inocache_lock);
+ 	if (!new->ino)
+ 		new->ino = ++c->highest_ino;
+ 
+ 	D2(printk(KERN_DEBUG "jffs2_add_ino_cache: Add %p (ino #%u)\n", new, new->ino));
 	
 	prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
 

fs/jffs2/write.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: write.c,v 1.91 2005/03/01 10:34:03 dedekind Exp $
+ * $Id: write.c,v 1.92 2005/04/13 13:22:35 dwmw2 Exp $
  *
  */
 
@@ -35,13 +35,12 @@ int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint
 	f->inocache = ic;
 	f->inocache->nlink = 1;
 	f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
-	f->inocache->ino = ++c->highest_ino;
 	f->inocache->state = INO_STATE_PRESENT;
 
-	ri->ino = cpu_to_je32(f->inocache->ino);
 
-	D1(printk(KERN_DEBUG "jffs2_do_new_inode(): Assigned ino# %d\n", f->inocache->ino));
 	jffs2_add_ino_cache(c, f->inocache);
+	D1(printk(KERN_DEBUG "jffs2_do_new_inode(): Assigned ino# %d\n", f->inocache->ino));
+	ri->ino = cpu_to_je32(f->inocache->ino);
 
 	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);