[JFFS2] Fix free space leak with in-band cleanmarkers
David Woodhouse
dwmw2 at infradead.org
Wed Apr 23 06:15:35 EDT 2008
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.
[Backport of commit 014b164e1392a166fe96e003d2f0e7ad2e2a0bb7]
Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
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;
down(&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);
--
dwmw2
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