[JFFS2] Fix node allocation leak

In the rare case of failing to write the cleanmarker
the allocated node was not freed.

Pointed out by Forrest Zhao
Initial cleanup by Joern Engel

Signed-off-by: Thomas Gleixner <[e-mail]>

fs/jffs2/erase.c

···
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: erase.c,v 1.76 2005/05/03 15:11:40 dedekind Exp $
+ * $Id: erase.c,v 1.80 2005/07/14 19:46:24 joern Exp $
  *
  */
 
···
 	jeb->last_node = NULL;
 }
 
+static int jffs2_block_check_erase(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t *bad_offset)
+{
+	void *ebuf;
+	uint32_t ofs;
+	size_t retlen;
+	int ret = -EIO;
+	
+	ebuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!ebuf) {
+		printk(KERN_WARNING "Failed to allocate page buffer for verifying erase at 0x%08x. Refiling\n", jeb->offset);
+		return -EAGAIN;
+	}
+
+	D1(printk(KERN_DEBUG "Verifying erase at 0x%08x\n", jeb->offset));
+
+	for (ofs = jeb->offset; ofs < jeb->offset + c->sector_size; ) {
+		uint32_t readlen = min((uint32_t)PAGE_SIZE, jeb->offset + c->sector_size - ofs);
+		int i;
+
+		*bad_offset = ofs;
+
+		ret = jffs2_flash_read(c, ofs, readlen, &retlen, ebuf);
+		if (ret) {
+			printk(KERN_WARNING "Read of newly-erased block at 0x%08x failed: %d. Putting on bad_list\n", ofs, ret);
+			goto fail;
+		}
+		if (retlen != readlen) {
+			printk(KERN_WARNING "Short read from newly-erased block at 0x%08x. Wanted %d, got %zd\n", ofs, readlen, retlen);
+			goto fail;
+		}
+		for (i=0; i<readlen; i += sizeof(unsigned long)) {
+			/* It's OK. We know it's properly aligned */
+			unsigned long *datum = ebuf + i;
+			if (*datum + 1) {
+				*bad_offset += i;
+				printk(KERN_WARNING "Newly-erased block contained word 0x%lx at offset 0x%08x\n", *datum, *bad_offset);
+				goto fail;
+			}
+		}
+		ofs += readlen;
+		cond_resched();
+	}
+	ret = 0;
+fail:
+	kfree(ebuf);
+	return ret;
+}
+
 static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 {
 	struct jffs2_raw_node_ref *marker_ref = NULL;
-	unsigned char *ebuf;
 	size_t retlen;
 	int ret;
 	uint32_t bad_offset;
 
-	if ((!jffs2_cleanmarker_oob(c)) && (c->cleanmarker_size > 0)) {
-		marker_ref = jffs2_alloc_raw_node_ref();
-		if (!marker_ref) {
-			printk(KERN_WARNING "Failed to allocate raw node ref for clean marker\n");
-			/* Stick it back on the list from whence it came and come back later */
-			jffs2_erase_pending_trigger(c);
-			spin_lock(&c->erase_completion_lock);
-			list_add(&jeb->list, &c->erase_complete_list);
-			spin_unlock(&c->erase_completion_lock);
-			return;
-		}
+	switch (jffs2_block_check_erase(c, jeb, &bad_offset)) {
+	case -EAGAIN:	goto refile;
+	case -EIO:	goto filebad;
 	}
-	ebuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!ebuf) {
-		printk(KERN_WARNING "Failed to allocate page buffer for verifying erase at 0x%08x. Assuming it worked\n", jeb->offset);
-	} else {
-		uint32_t ofs = jeb->offset;
-
-		D1(printk(KERN_DEBUG "Verifying erase at 0x%08x\n", jeb->offset));
-		while(ofs < jeb->offset + c->sector_size) {
-			uint32_t readlen = min((uint32_t)PAGE_SIZE, jeb->offset + c->sector_size - ofs);
-			int i;
-
-			bad_offset = ofs;
-
-			ret = c->mtd->read(c->mtd, ofs, readlen, &retlen, ebuf);
-
-			if (ret) {
-				printk(KERN_WARNING "Read of newly-erased block at 0x%08x failed: %d. Putting on bad_list\n", ofs, ret);
-				goto bad;
-			}
-			if (retlen != readlen) {
-				printk(KERN_WARNING "Short read from newly-erased block at 0x%08x. Wanted %d, got %zd\n", ofs, readlen, retlen);
-				goto bad;
-			}
-			for (i=0; i<readlen; i += sizeof(unsigned long)) {
-				/* It's OK. We know it's properly aligned */
-				unsigned long datum = *(unsigned long *)(&ebuf[i]);
-				if (datum + 1) {
-					bad_offset += i;
-					printk(KERN_WARNING "Newly-erased block contained word 0x%lx at offset 0x%08x\n", datum, bad_offset);
-				bad: 
-					if ((!jffs2_cleanmarker_oob(c)) && (c->cleanmarker_size > 0))
-						jffs2_free_raw_node_ref(marker_ref);
-					kfree(ebuf);
-				bad2:
-					spin_lock(&c->erase_completion_lock);
-					/* Stick it on a list (any list) so
-					   erase_failed can take it right off
-					   again.  Silly, but shouldn't happen
-					   often. */
-					list_add(&jeb->list, &c->erasing_list);
-					spin_unlock(&c->erase_completion_lock);
-					jffs2_erase_failed(c, jeb, bad_offset);
-					return;
-				}
-			}
-			ofs += readlen;
-			cond_resched();
-		}
-		kfree(ebuf);
-	}
-
-	bad_offset = jeb->offset;
 
 	/* Write the erase complete marker */	
 	D1(printk(KERN_DEBUG "Writing erased marker to block at 0x%08x\n", jeb->offset));
-	if (jffs2_cleanmarker_oob(c)) {
+	bad_offset = jeb->offset;
 
-		if (jffs2_write_nand_cleanmarker(c, jeb))
-			goto bad2;
-			
+	/* Cleanmarker in oob area or no cleanmarker at all ? */
+	if (jffs2_cleanmarker_oob(c) || c->cleanmarker_size == 0) {
+
+		if (jffs2_cleanmarker_oob(c)) {
+			if (jffs2_write_nand_cleanmarker(c, jeb))
+				goto filebad;
+		}
+
 		jeb->first_node = jeb->last_node = NULL;
-
 		jeb->free_size = c->sector_size;
 		jeb->used_size = 0;
 		jeb->dirty_size = 0;
 		jeb->wasted_size = 0;
-	} else if (c->cleanmarker_size == 0) {
-		jeb->first_node = jeb->last_node = NULL;
 
-		jeb->free_size = c->sector_size;
-		jeb->used_size = 0;
-		jeb->dirty_size = 0;
-		jeb->wasted_size = 0;
 	} else {
+
 		struct kvec vecs[1];
 		struct jffs2_unknown_node marker = {
 			.magic =	cpu_to_je16(JFFS2_MAGIC_BITMASK),
···
 			.totlen =	cpu_to_je32(c->cleanmarker_size)
 		};
 
+		marker_ref = jffs2_alloc_raw_node_ref();
+		if (!marker_ref) {
+			printk(KERN_WARNING "Failed to allocate raw node ref for clean marker. Refiling\n");
+			goto refile;
+		}
+
 		marker.hdr_crc = cpu_to_je32(crc32(0, &marker, sizeof(struct jffs2_unknown_node)-4));
 
 		vecs[0].iov_base = (unsigned char *) &marker;
 		vecs[0].iov_len = sizeof(marker);
 		ret = jffs2_flash_direct_writev(c, vecs, 1, jeb->offset, &retlen);
 		
-		if (ret) {
-			printk(KERN_WARNING "Write clean marker to block at 0x%08x failed: %d\n",
-			       jeb->offset, ret);
-			goto bad2;
-		}
-		if (retlen != sizeof(marker)) {
-			printk(KERN_WARNING "Short write to newly-erased block at 0x%08x: Wanted %zd, got %zd\n",
-			       jeb->offset, sizeof(marker), retlen);
-			goto bad2;
+		if (ret || retlen != sizeof(marker)) {
+			if (ret)
+				printk(KERN_WARNING "Write clean marker to block at 0x%08x failed: %d\n",
+				       jeb->offset, ret);
+			else
+				printk(KERN_WARNING "Short write to newly-erased block at 0x%08x: Wanted %zd, got %zd\n",
+				       jeb->offset, sizeof(marker), retlen);
+
+			jffs2_free_raw_node_ref(marker_ref);
+			goto filebad;
 		}
 
 		marker_ref->next_in_ino = NULL;
···
 	c->nr_free_blocks++;
 	spin_unlock(&c->erase_completion_lock);
 	wake_up(&c->erase_wait);
-}
+	return;
 
+filebad:
+	spin_lock(&c->erase_completion_lock);
+	/* Stick it on a list (any list) so erase_failed can take it
+	   right off again.  Silly, but shouldn't happen often. */
+	list_add(&jeb->list, &c->erasing_list);
+	spin_unlock(&c->erase_completion_lock);
+	jffs2_erase_failed(c, jeb, bad_offset);
+	return;
+
+refile:
+	/* Stick it back on the list from whence it came and come back later */
+	jffs2_erase_pending_trigger(c);
+	spin_lock(&c->erase_completion_lock);
+	list_add(&jeb->list, &c->erase_complete_list);
+	spin_unlock(&c->erase_completion_lock);
+	return;
+}