axmap: ensure that overlaps are handled strictly sequential

[fio.git] / lib / axmap.c

diff --git a/lib/axmap.c b/lib/axmap.c
index 195d333c58d28c7d54e7c45b552a70781e3e08ca..c29597f80e78748043b63db3756463596c164646 100644 (file)
--- a/lib/axmap.c
+++ b/lib/axmap.c
@@ -102,7 +102,7 @@ struct axmap *axmap_new(unsigned long nr_bits)
        }
 
        axmap->nr_levels = levels;
-       axmap->levels = malloc(axmap->nr_levels * sizeof(struct axmap_level));
+       axmap->levels = calloc(axmap->nr_levels, sizeof(struct axmap_level));
        axmap->nr_bits = nr_bits;
 
        for (i = 0; i < axmap->nr_levels; i++) {
@@ -125,12 +125,12 @@ err:
                        free(axmap->levels[i].map);
 
        free(axmap->levels);
-        free(axmap);
+       free(axmap);
        return NULL;
 }
 
-static int axmap_handler(struct axmap *axmap, uint64_t bit_nr,
-                         int (*func)(struct axmap_level *, unsigned long, unsigned int,
+static bool axmap_handler(struct axmap *axmap, uint64_t bit_nr,
+                         bool (*func)(struct axmap_level *, unsigned long, unsigned int,
                          void *), void *data)
 {
        struct axmap_level *al;
@@ -144,14 +144,14 @@ static int axmap_handler(struct axmap *axmap, uint64_t bit_nr,
                al = &axmap->levels[i];
 
                if (func(al, offset, bit, data))
-                       return 1;
+                       return true;
        }
 
-       return 0;
+       return false;
 }
 
-static int axmap_handler_topdown(struct axmap *axmap, uint64_t bit_nr,
-       int (*func)(struct axmap_level *, unsigned long, unsigned int, void *),
+static bool axmap_handler_topdown(struct axmap *axmap, uint64_t bit_nr,
+       bool (*func)(struct axmap_level *, unsigned long, unsigned int, void *),
        void *data)
 {
        struct axmap_level *al;
@@ -165,25 +165,28 @@ static int axmap_handler_topdown(struct axmap *axmap, uint64_t bit_nr,
                al = &axmap->levels[i];
 
                if (func(al, offset, bit, data))
-                       return 1;
+                       return true;
        }
 
-       return 0;
+       return false;
 }
 
-static int axmap_clear_fn(struct axmap_level *al, unsigned long offset,
+static bool axmap_clear_fn(struct axmap_level *al, unsigned long offset,
                           unsigned int bit, void *unused)
 {
        if (!(al->map[offset] & (1UL << bit)))
-               return 1;
+               return true;
 
        al->map[offset] &= ~(1UL << bit);
-       return 0;
+       return false;
 }
 
 void axmap_clear(struct axmap *axmap, uint64_t bit_nr)
 {
        axmap_handler(axmap, bit_nr, axmap_clear_fn, NULL);
+
+       if (bit_nr < axmap->first_free)
+               axmap->first_free = bit_nr;
 }
 
 struct axmap_set_data {
@@ -191,7 +194,7 @@ struct axmap_set_data {
        unsigned int set_bits;
 };
 
-static unsigned long bit_masks[] = {
+static const unsigned long bit_masks[] = {
        0x0000000000000000, 0x0000000000000001, 0x0000000000000003, 0x0000000000000007,
        0x000000000000000f, 0x000000000000001f, 0x000000000000003f, 0x000000000000007f,
        0x00000000000000ff, 0x00000000000001ff, 0x00000000000003ff, 0x00000000000007ff,
@@ -213,7 +216,7 @@ static unsigned long bit_masks[] = {
 #endif
 };
 
-static int axmap_set_fn(struct axmap_level *al, unsigned long offset,
+static bool axmap_set_fn(struct axmap_level *al, unsigned long offset,
                         unsigned int bit, void *__data)
 {
        struct axmap_set_data *data = __data;
@@ -229,19 +232,20 @@ static int axmap_set_fn(struct axmap_level *al, unsigned long offset,
         */
        overlap = al->map[offset] & mask;
        if (overlap == mask)
-               return 1;
+               return true;
+
+       if (overlap) {
+               const int __bit = ffz(~overlap);
 
-       while (overlap) {
-               unsigned long clear_mask = ~(1UL << ffz(~overlap));
+               if (__bit == bit)
+                       return true;
 
-               mask &= clear_mask;
-               overlap &= clear_mask;
-               nr_bits--;
+               nr_bits = __bit - bit;
+               mask = bit_masks[nr_bits] << bit;
        }
 
        assert(mask);
        assert(!(al->map[offset] & mask));
-               
        al->map[offset] |= mask;
 
        if (!al->level)
@@ -290,7 +294,8 @@ void axmap_set(struct axmap *axmap, uint64_t bit_nr)
        __axmap_set(axmap, bit_nr, &data);
 }
 
-unsigned int axmap_set_nr(struct axmap *axmap, uint64_t bit_nr, unsigned int nr_bits)
+unsigned int axmap_set_nr(struct axmap *axmap, uint64_t bit_nr,
+                         unsigned int nr_bits)
 {
        unsigned int set_bits = 0;
 
@@ -315,18 +320,18 @@ unsigned int axmap_set_nr(struct axmap *axmap, uint64_t bit_nr, unsigned int nr_
        return set_bits;
 }
 
-static int axmap_isset_fn(struct axmap_level *al, unsigned long offset,
-                           unsigned int bit, void *unused)
+static bool axmap_isset_fn(struct axmap_level *al, unsigned long offset,
+                          unsigned int bit, void *unused)
 {
        return (al->map[offset] & (1UL << bit)) != 0;
 }
 
-int axmap_isset(struct axmap *axmap, uint64_t bit_nr)
+bool axmap_isset(struct axmap *axmap, uint64_t bit_nr)
 {
        if (bit_nr <= axmap->nr_bits)
                return axmap_handler_topdown(axmap, bit_nr, axmap_isset_fn, NULL);
 
-       return 0;
+       return false;
 }
 
 static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
@@ -371,10 +376,9 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 
 static uint64_t axmap_first_free(struct axmap *axmap)
 {
-       if (firstfree_valid(axmap))
-               return axmap->first_free;
+       if (!firstfree_valid(axmap))
+               axmap->first_free = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
 
-       axmap->first_free = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
        return axmap->first_free;
 }
 
@@ -384,23 +388,23 @@ struct axmap_next_free_data {
        uint64_t bit;
 };
 
-static int axmap_next_free_fn(struct axmap_level *al, unsigned long offset,
+static bool axmap_next_free_fn(struct axmap_level *al, unsigned long offset,
                               unsigned int bit, void *__data)
 {
        struct axmap_next_free_data *data = __data;
        uint64_t mask = ~bit_masks[(data->bit + 1) & BLOCKS_PER_UNIT_MASK];
 
        if (!(mask & ~al->map[offset]))
-               return 0;
+               return false;
 
        if (al->map[offset] != -1UL) {
                data->level = al->level;
                data->offset = offset;
-               return 1;
+               return true;
        }
 
        data->bit = (data->bit + BLOCKS_PER_UNIT - 1) / BLOCKS_PER_UNIT;
-       return 0;
+       return false;
 }
 
 /*