drbd: allow petabyte storage on 64bit arch
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 74cc50a..5a2d0ec 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1003,9 +1003,9 @@
struct hlist_head *tl_hash;
unsigned int tl_hash_s;
- /* blocks to sync in this run [unit BM_BLOCK_SIZE] */
+ /* blocks to resync in this run [unit BM_BLOCK_SIZE] */
unsigned long rs_total;
- /* number of sync IOs that failed in this run */
+ /* number of resync blocks that failed in this run */
unsigned long rs_failed;
/* Syncer's start time [unit jiffies] */
unsigned long rs_start;
@@ -1399,7 +1399,9 @@
* you should use 64bit OS for that much storage, anyways. */
#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff)
#else
-#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0x1LU << 32)
+/* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */
+#define DRBD_MAX_SECTORS_FLEX (1UL << 51)
+/* corresponds to (1UL << 38) bits right now. */
#endif
#endif
@@ -1419,11 +1421,15 @@
extern void drbd_bm_cleanup(struct drbd_conf *mdev);
extern void drbd_bm_set_all(struct drbd_conf *mdev);
extern void drbd_bm_clear_all(struct drbd_conf *mdev);
+/* set/clear/test only a few bits at a time */
extern int drbd_bm_set_bits(
struct drbd_conf *mdev, unsigned long s, unsigned long e);
extern int drbd_bm_clear_bits(
struct drbd_conf *mdev, unsigned long s, unsigned long e);
-/* bm_set_bits variant for use while holding drbd_bm_lock */
+extern int drbd_bm_count_bits(
+ struct drbd_conf *mdev, const unsigned long s, const unsigned long e);
+/* bm_set_bits variant for use while holding drbd_bm_lock,
+ * may process the whole bitmap in one go */
extern void _drbd_bm_set_bits(struct drbd_conf *mdev,
const unsigned long s, const unsigned long e);
extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr);
@@ -1436,6 +1442,8 @@
extern size_t drbd_bm_words(struct drbd_conf *mdev);
extern unsigned long drbd_bm_bits(struct drbd_conf *mdev);
extern sector_t drbd_bm_capacity(struct drbd_conf *mdev);
+
+#define DRBD_END_OF_BITMAP (~(unsigned long)0)
extern unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo);
/* bm_find_next variants for use while you hold drbd_bm_lock() */
extern unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo);
@@ -1452,8 +1460,6 @@
extern void drbd_bm_lock(struct drbd_conf *mdev, char *why);
extern void drbd_bm_unlock(struct drbd_conf *mdev);
-
-extern int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e);
/* drbd_main.c */
extern struct kmem_cache *drbd_request_cache;
@@ -2158,10 +2164,8 @@
static inline void drbd_get_syncer_progress(struct drbd_conf *mdev,
unsigned long *bits_left, unsigned int *per_mil_done)
{
- /*
- * this is to break it at compile time when we change that
- * (we may feel 4TB maximum storage per drbd is not enough)
- */
+ /* this is to break it at compile time when we change that, in case we
+ * want to support more than (1<<32) bits on a 32bit arch. */
typecheck(unsigned long, mdev->rs_total);
/* note: both rs_total and rs_left are in bits, i.e. in
@@ -2186,10 +2190,19 @@
*bits_left, mdev->rs_total, mdev->rs_failed);
*per_mil_done = 0;
} else {
- /* make sure the calculation happens in long context */
- unsigned long tmp = 1000UL -
- (*bits_left >> 10)*1000UL
- / ((mdev->rs_total >> 10) + 1UL);
+ /* Make sure the division happens in long context.
+ * We allow up to one petabyte storage right now,
+ * at a granularity of 4k per bit that is 2**38 bits.
+ * After shift right and multiplication by 1000,
+ * this should still fit easily into a 32bit long,
+ * so we don't need a 64bit division on 32bit arch.
+ * Note: currently we don't support such large bitmaps on 32bit
+ * arch anyways, but no harm done to be prepared for it here.
+ */
+ unsigned int shift = mdev->rs_total >= (1ULL << 32) ? 16 : 10;
+ unsigned long left = *bits_left >> shift;
+ unsigned long total = 1UL + (mdev->rs_total >> shift);
+ unsigned long tmp = 1000UL - left * 1000UL/total;
*per_mil_done = tmp;
}
}
