[JFFS2] Trigger garbage collection when very_dirty_list size becomes excessive
With huge amounts of free space, we weren't bothering to GC for while a
while, and pathological numbers of obsolete nodes were accumulating,
seriously affecting performance on NAND flash (OLPC trac #3978)
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index ae99cd7..3a2197f 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -69,6 +69,8 @@
uint8_t resv_blocks_gctrigger; /* ... wake up the GC thread */
uint8_t resv_blocks_gcbad; /* ... pick a block from the bad_list to GC */
uint8_t resv_blocks_gcmerge; /* ... merge pages when garbage collecting */
+ /* Number of 'very dirty' blocks before we trigger immediate GC */
+ uint8_t vdirty_blocks_gctrigger;
uint32_t nospc_dirty_size;