[JFFS2] Fix free space leak with in-band cleanmarkers

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=014b164e1392a166fe96e003d2f0e7ad2e2a0bb7
Commit:     014b164e1392a166fe96e003d2f0e7ad2e2a0bb7
Parent:     cf9d1e428cc28ef5798aeda0822a6ce64849a439
Author:     David Woodhouse <dwmw2 at infradead.org>
AuthorDate: Tue Apr 22 23:54:38 2008 +0100
Committer:  David Woodhouse <dwmw2 at infradead.org>
CommitDate: Tue Apr 22 23:54:38 2008 +0100

    [JFFS2] Fix free space leak with in-band cleanmarkers
    
    We were accounting for the cleanmarker by calling jffs2_link_node_ref()
    (without locking!), which adjusted both superblock and per-eraseblock
    accounting, subtracting the size of the cleanmarker from {jeb,c}->free_size
    and adding it to {jeb,c}->used_size.
    
    But only _then_ were we adding the size of the newly-erased block back
    to the superblock counts, and we were adding each of jeb->{free,used}_size
    to the corresponding superblock counts. Thus, the size of the cleanmarker
    was effectively subtracted from the superblock's free_size _twice_.
    
    Fix this, by always adding a full eraseblock size to c->free_size when
    we've erased a block. And call jffs2_link_node_ref() under the proper
    lock, while we're at it.
    
    Thanks to Alexander Yurchenko and/or Damir Shayhutdinov for (almost)
    pinpointing the problem.
    
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
 fs/jffs2/erase.c |   18 ++++++++----------
 1 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/jffs2/erase.c b/fs/jffs2/erase.c
index 96d9ad5..bdc6a7b 100644
--- a/fs/jffs2/erase.c
+++ b/fs/jffs2/erase.c
@@ -419,9 +419,6 @@ static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseb
 			if (jffs2_write_nand_cleanmarker(c, jeb))
 				goto filebad;
 		}
-
-		/* Everything else got zeroed before the erase */
-		jeb->free_size = c->sector_size;
 	} else {
 
 		struct kvec vecs[1];
@@ -449,18 +446,19 @@ static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseb
 
 			goto filebad;
 		}
-
-		/* Everything else got zeroed before the erase */
-		jeb->free_size = c->sector_size;
-		/* FIXME Special case for cleanmarker in empty block */
-		jffs2_link_node_ref(c, jeb, jeb->offset | REF_NORMAL, c->cleanmarker_size, NULL);
 	}
+	/* Everything else got zeroed before the erase */
+	jeb->free_size = c->sector_size;
 
 	mutex_lock(&c->erase_free_sem);
 	spin_lock(&c->erase_completion_lock);
+
 	c->erasing_size -= c->sector_size;
-	c->free_size += jeb->free_size;
-	c->used_size += jeb->used_size;
+	c->free_size += c->sector_size;
+
+	/* Account for cleanmarker now, if it's in-band */
+	if (c->cleanmarker_size && !jffs2_cleanmarker_oob(c))
+		jffs2_link_node_ref(c, jeb, jeb->offset | REF_NORMAL, c->cleanmarker_size, NULL);
 
 	jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);