UBIFS: use nicer 64-bit math

Instead of using do_div(), use better primitives from
linux/math64.h.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 11 insertions, 14 deletions

diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index e42342547001..0bcb8031ca18 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -32,7 +32,7 @@
 
 #include "ubifs.h"
 #include <linux/writeback.h>
-#include <asm/div64.h>
+#include <linux/math64.h>
 
 /*
  * When pessimistic budget calculations say that there is no enough space,
@@ -258,8 +258,8 @@ static int make_free_space(struct ubifs_info *c, struct retries_info *ri)
  */
 int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
 {
-        int ret;
-        uint64_t idx_size;
+        int idx_lebs, eff_leb_size = c->leb_size - c->max_idx_node_sz;
+        long long idx_size;
 
         idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
 
@@ -271,18 +271,16 @@ int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
          * pair, nor similarly the two variables for the new index size, so we
          * have to do this costly 64-bit division on fast-path.
          */
-        if (do_div(idx_size, c->leb_size - c->max_idx_node_sz))
-                ret = idx_size + 1;
-        else
-                ret = idx_size;
+        idx_size += eff_leb_size - 1;
+        idx_lebs = div_u64(idx_size, eff_leb_size);
         /*
          * The index head is not available for the in-the-gaps method, so add an
          * extra LEB to compensate.
          */
-        ret += 1;
-        if (ret < MIN_INDEX_LEBS)
-                ret = MIN_INDEX_LEBS;
-        return ret;
+        idx_lebs += 1;
+        if (idx_lebs < MIN_INDEX_LEBS)
+                idx_lebs = MIN_INDEX_LEBS;
+        return idx_lebs;
 }
 
 /**
@@ -718,7 +716,7 @@ void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
  * Note, the calculation is pessimistic, which means that most of the time
  * UBIFS reports less space than it actually has.
  */
-long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free)
+long long ubifs_reported_space(const struct ubifs_info *c, long long free)
 {
         int divisor, factor, f;
 
@@ -740,8 +738,7 @@ long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free)
         divisor = UBIFS_MAX_DATA_NODE_SZ;
         divisor += (c->max_idx_node_sz * 3) / (f - 1);
         free *= factor;
-        do_div(free, divisor);
-        return free;
+        return div_u64(free, divisor);
 }
 
 /**