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>

6 files changed, 30 insertions, 35 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);
 }
 
 /**
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 6ecb01a99d14..a2be11584ad3 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -33,6 +33,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/debugfs.h>
+#include <linux/math64.h>
 
 #ifdef CONFIG_UBIFS_FS_DEBUG
 
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 6d914160ec55..b2792e84d245 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -43,8 +43,9 @@
  * mounted.
  */
 
-#include <linux/crc16.h>
 #include "ubifs.h"
+#include <linux/crc16.h>
+#include <linux/math64.h>
 
 /**
  * do_calc_lpt_geom - calculate sizes for the LPT area.
@@ -135,15 +136,13 @@ static void do_calc_lpt_geom(struct ubifs_info *c)
 int ubifs_calc_lpt_geom(struct ubifs_info *c)
 {
         int lebs_needed;
-        uint64_t sz;
+        long long sz;
 
         do_calc_lpt_geom(c);
 
         /* Verify that lpt_lebs is big enough */
         sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
-        sz += c->leb_size - 1;
-        do_div(sz, c->leb_size);
-        lebs_needed = sz;
+        lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
         if (lebs_needed > c->lpt_lebs) {
                 ubifs_err("too few LPT LEBs");
                 return -EINVAL;
@@ -175,7 +174,7 @@ static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
                               int *big_lpt)
 {
         int i, lebs_needed;
-        uint64_t sz;
+        long long sz;
 
         /* Start by assuming the minimum number of LPT LEBs */
         c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
@@ -202,9 +201,7 @@ static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
         /* Now check there are enough LPT LEBs */
         for (i = 0; i < 64 ; i++) {
                 sz = c->lpt_sz * 4; /* Allow 4 times the size */
-                sz += c->leb_size - 1;
-                do_div(sz, c->leb_size);
-                lebs_needed = sz;
+                lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
                 if (lebs_needed > c->lpt_lebs) {
                         /* Not enough LPT LEBs so try again with more */
                         c->lpt_lebs = lebs_needed;
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index c5da201ab54f..e070c643d1bb 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -28,6 +28,7 @@
 
 #include "ubifs.h"
 #include <linux/random.h>
+#include <linux/math64.h>
 
 /*
  * Default journal size in logical eraseblocks as a percent of total
@@ -80,7 +81,7 @@ static int create_default_filesystem(struct ubifs_info *c)
         int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
         int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
         int min_leb_cnt = UBIFS_MIN_LEB_CNT;
-        uint64_t tmp64, main_bytes;
+        long long tmp64, main_bytes;
         __le64 tmp_le64;
 
         /* Some functions called from here depend on the @c->key_len filed */
@@ -160,7 +161,7 @@ static int create_default_filesystem(struct ubifs_info *c)
         if (!sup)
                 return -ENOMEM;
 
-        tmp64 = (uint64_t)max_buds * c->leb_size;
+        tmp64 = (long long)max_buds * c->leb_size;
         if (big_lpt)
                 sup_flags |= UBIFS_FLG_BIGLPT;
 
@@ -187,9 +188,8 @@ static int create_default_filesystem(struct ubifs_info *c)
 
         generate_random_uuid(sup->uuid);
 
-        main_bytes = (uint64_t)main_lebs * c->leb_size;
-        tmp64 = main_bytes * DEFAULT_RP_PERCENT;
-        do_div(tmp64, 100);
+        main_bytes = (long long)main_lebs * c->leb_size;
+        tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
         if (tmp64 > DEFAULT_MAX_RP_SIZE)
                 tmp64 = DEFAULT_MAX_RP_SIZE;
         sup->rp_size = cpu_to_le64(tmp64);
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index a6a7798d020b..c3cefc841374 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -34,6 +34,7 @@
 #include <linux/parser.h>
 #include <linux/seq_file.h>
 #include <linux/mount.h>
+#include <linux/math64.h>
 #include "ubifs.h"
 
 /*
@@ -612,7 +613,7 @@ static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
 static int init_constants_late(struct ubifs_info *c)
 {
         int tmp, err;
-        uint64_t tmp64;
+        long long tmp64;
 
         c->main_bytes = (long long)c->main_lebs * c->leb_size;
         c->max_znode_sz = sizeof(struct ubifs_znode) +
@@ -639,9 +640,8 @@ static int init_constants_late(struct ubifs_info *c)
          * Make sure that the log is large enough to fit reference nodes for
          * all buds plus one reserved LEB.
          */
-        tmp64 = c->max_bud_bytes;
-        tmp = do_div(tmp64, c->leb_size);
-        c->max_bud_cnt = tmp64 + !!tmp;
+        tmp64 = c->max_bud_bytes + c->leb_size - 1;
+        c->max_bud_cnt = div_u64(tmp64, c->leb_size);
         tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
         tmp /= c->leb_size;
         tmp += 1;
@@ -677,7 +677,7 @@ static int init_constants_late(struct ubifs_info *c)
          * Consequently, if the journal is too small, UBIFS will treat it as
          * always full.
          */
-        tmp64 = (uint64_t)(c->jhead_cnt + 1) * c->leb_size + 1;
+        tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
         if (c->bg_bud_bytes < tmp64)
                 c->bg_bud_bytes = tmp64;
         if (c->max_bud_bytes < tmp64 + c->leb_size)
@@ -699,7 +699,7 @@ static int init_constants_late(struct ubifs_info *c)
          * head is available.
          */
         tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
-        tmp64 *= (uint64_t)c->leb_size - c->leb_overhead;
+        tmp64 *= (long long)c->leb_size - c->leb_overhead;
         tmp64 = ubifs_reported_space(c, tmp64);
         c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
 
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 543e850022eb..a17dd794ae92 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1498,7 +1498,7 @@ void ubifs_cancel_ino_op(struct ubifs_info *c, struct inode *inode,
 long long ubifs_get_free_space(struct ubifs_info *c);
 int ubifs_calc_min_idx_lebs(struct ubifs_info *c);
 void ubifs_convert_page_budget(struct ubifs_info *c);
-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);
 long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs);
 
 /* find.c */