patch-2.4.23 linux-2.4.23/fs/jffs2/gc.c

• Lines: 73
• Date: 2003-11-28 10:26:21.000000000 -0800
• Orig file: linux-2.4.22/fs/jffs2/gc.c
• Orig date: 2003-08-25 04:44:43.000000000 -0700

diff -urN linux-2.4.22/fs/jffs2/gc.c linux-2.4.23/fs/jffs2/gc.c
@@ -31,7 +31,7 @@
  * provisions above, a recipient may use your version of this file
  * under either the RHEPL or the GPL.
  *
- * $Id: gc.c,v 1.52.2.5 2002/10/10 13:18:38 dwmw2 Exp $
+ * $Id: gc.c,v 1.52.2.7 2003/11/02 13:54:20 dwmw2 Exp $
  *
  */
 
@@ -109,8 +109,8 @@
 	struct jffs2_node_frag *frag;
 	struct jffs2_full_dnode *fn = NULL;
 	struct jffs2_full_dirent *fd;
+	struct jffs2_inode_cache *ic;
 	__u32 start = 0, end = 0, nrfrags = 0;
-	__u32 inum;
 	struct inode *inode;
 	int ret = 0;
 
@@ -162,16 +162,47 @@
 		goto eraseit_lock;
 	}
 						     
-	inum = jffs2_raw_ref_to_inum(raw);
-	D1(printk(KERN_DEBUG "Inode number is #%u\n", inum));
+	ic = jffs2_raw_ref_to_ic(raw);
+	D1(printk(KERN_DEBUG "Inode number is #%u\n", ic->ino));
 
 	spin_unlock_bh(&c->erase_completion_lock);
 
-	D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass collecting from block @0x%08x. Node @0x%08x, ino #%u\n", jeb->offset, raw->flash_offset&~3, inum));
-
-	inode = iget(OFNI_BS_2SFFJ(c), inum);
+	D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass collecting from block @0x%08x. Node @0x%08x, ino #%u\n", jeb->offset, raw->flash_offset&~3, ic->ino));
+	if (!ic->nlink) {
+		/* The inode has zero nlink but its nodes weren't yet marked
+		   obsolete. This has to be because we're still waiting for 
+		   the final (close() and) iput() to happen.
+
+		   There's a possibility that the final iput() could have 
+		   happened while we were contemplating. In order to ensure
+		   that we don't cause a new read_inode() (which would fail)
+		   for the inode in question, we use ilookup() in this case
+		   instead of iget().
+
+		   The nlink can't _become_ zero at this point because we're 
+		   holding the alloc_sem, and jffs2_do_unlink() would also
+		   need that while decrementing nlink on any inode.
+		*/
+		inode = ilookup(OFNI_BS_2SFFJ(c), ic->ino);
+		if (!inode) {
+			D1(printk(KERN_DEBUG "ilookup() failed for ino #%u; inode is probably deleted.\n",
+				  ic->ino));
+			up(&c->alloc_sem);
+			return 0;
+		}
+	} else {
+		/* Inode has links to it still; they're not going away because
+		   jffs2_do_unlink() would need the alloc_sem and we have it.
+		   Just iget() it, and if read_inode() is necessary that's OK.
+		*/
+		inode = iget(OFNI_BS_2SFFJ(c), ic->ino);
+		if (!inode) {
+			up(&c->alloc_sem);
+			return -ENOMEM;
+		}
+	}
 	if (is_bad_inode(inode)) {
-		printk(KERN_NOTICE "Eep. read_inode() failed for ino #%u\n", inum);
+		printk(KERN_NOTICE "Eep. read_inode() failed for ino #%u\n", ic->ino);
 		/* NB. This will happen again. We need to do something appropriate here. */
 		up(&c->alloc_sem);
 		iput(inode);