md/bitmap: fix calculation of 'chunks' - missing shift.
commit 61a0d80c "md/bitmap: discard CHUNK_BLOCK_SHIFT macro"
replaced CHUNK_BLOCK_RATIO() by the same text that was
replacing CHUNK_BLOCK_SHIFT() - which is clearly wrong.
The result is that 'chunks' is often too small by 1,
which can sometimes result in a crash (not sure how).
So use the correct replacement, and get rid of CHUNK_BLOCK_RATIO
which is no longe used.
Reported-by: Karl Newman <siliconfiend@gmail.com>
Tested-by: Karl Newman <siliconfiend@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 97e73e5..17e2b47 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1727,8 +1727,7 @@
bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
- BITMAP_BLOCK_SHIFT);
- /* now that chunksize and chunkshift are set, we can use these macros */
- chunks = (blocks + bitmap->chunkshift - 1) >>
+ chunks = (blocks + (1 << bitmap->chunkshift) - 1) >>
bitmap->chunkshift;
pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 55ca5ae..b44b0aba 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -101,9 +101,6 @@
#define BITMAP_BLOCK_SHIFT 9
-/* how many blocks per chunk? (this is variable) */
-#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->mddev->bitmap_info.chunksize >> BITMAP_BLOCK_SHIFT)
-
#endif
/*