axmap: ensure that overlaps are handled strictly sequential

[fio.git] / lib / axmap.c

diff --git a/lib/axmap.c b/lib/axmap.c
index 8247fc1ae5d75f8aa452f2018bf248a6cc3a36a7..c29597f80e78748043b63db3756463596c164646 100644 (file)
--- a/lib/axmap.c
+++ b/lib/axmap.c
@@ -22,8 +22,6 @@
 
 #include "../arch/arch.h"
 #include "axmap.h"
-#include "../smalloc.h"
-#include "../mutex.h"
 #include "../minmax.h"
 
 #if BITS_PER_LONG == 64
@@ -46,7 +44,6 @@ struct axmap_level {
 };
 
 struct axmap {
-       struct fio_mutex lock;
        unsigned int nr_levels;
        struct axmap_level *levels;
        uint64_t first_free;
@@ -65,8 +62,6 @@ void axmap_reset(struct axmap *axmap)
 {
        int i;
 
-       fio_mutex_down(&axmap->lock);
-
        for (i = 0; i < axmap->nr_levels; i++) {
                struct axmap_level *al = &axmap->levels[i];
 
@@ -74,7 +69,6 @@ void axmap_reset(struct axmap *axmap)
        }
 
        axmap->first_free = 0;
-       fio_mutex_up(&axmap->lock);
 }
 
 void axmap_free(struct axmap *axmap)
@@ -85,11 +79,10 @@ void axmap_free(struct axmap *axmap)
                return;
 
        for (i = 0; i < axmap->nr_levels; i++)
-               sfree(axmap->levels[i].map);
+               free(axmap->levels[i].map);
 
-       sfree(axmap->levels);
-       __fio_mutex_remove(&axmap->lock);
-       sfree(axmap);
+       free(axmap->levels);
+       free(axmap);
 }
 
 struct axmap *axmap_new(unsigned long nr_bits)
@@ -97,12 +90,10 @@ struct axmap *axmap_new(unsigned long nr_bits)
        struct axmap *axmap;
        unsigned int i, levels;
 
-       axmap = smalloc(sizeof(*axmap));
+       axmap = malloc(sizeof(*axmap));
        if (!axmap)
                return NULL;
 
-       __fio_mutex_init(&axmap->lock, FIO_MUTEX_UNLOCKED);
-
        levels = 1;
        i = (nr_bits + BLOCKS_PER_UNIT - 1) >> UNIT_SHIFT;
        while (i > 1) {
@@ -111,7 +102,7 @@ struct axmap *axmap_new(unsigned long nr_bits)
        }
 
        axmap->nr_levels = levels;
-       axmap->levels = smalloc(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++) {
@@ -119,7 +110,7 @@ struct axmap *axmap_new(unsigned long nr_bits)
 
                al->level = i;
                al->map_size = (nr_bits + BLOCKS_PER_UNIT - 1) >> UNIT_SHIFT;
-               al->map = smalloc(al->map_size * sizeof(unsigned long));
+               al->map = malloc(al->map_size * sizeof(unsigned long));
                if (!al->map)
                        goto err;
 
@@ -131,16 +122,15 @@ struct axmap *axmap_new(unsigned long nr_bits)
 err:
        for (i = 0; i < axmap->nr_levels; i++)
                if (axmap->levels[i].map)
-                       sfree(axmap->levels[i].map);
+                       free(axmap->levels[i].map);
 
-       sfree(axmap->levels);
-       __fio_mutex_remove(&axmap->lock);
-       sfree(axmap);
+       free(axmap->levels);
+       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;
@@ -154,14 +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;
@@ -175,25 +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 {
@@ -201,7 +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,
@@ -223,7 +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;
@@ -239,19 +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;
 
-       while (overlap) {
-               unsigned long clear_mask = ~(1UL << ffz(~overlap));
+       if (overlap) {
+               const int __bit = ffz(~overlap);
 
-               mask &= clear_mask;
-               overlap &= clear_mask;
-               nr_bits--;
+               if (__bit == bit)
+                       return true;
+
+               nr_bits = __bit - bit;
+               mask = bit_masks[nr_bits] << bit;
        }
 
        assert(mask);
        assert(!(al->map[offset] & mask));
-               
        al->map[offset] |= mask;
 
        if (!al->level)
@@ -297,12 +291,11 @@ void axmap_set(struct axmap *axmap, uint64_t bit_nr)
 {
        struct axmap_set_data data = { .nr_bits = 1, };
 
-       fio_mutex_down(&axmap->lock);
        __axmap_set(axmap, bit_nr, &data);
-       fio_mutex_up(&axmap->lock);
 }
 
-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;
 
@@ -327,24 +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) {
-               int ret;
+       if (bit_nr <= axmap->nr_bits)
+               return axmap_handler_topdown(axmap, bit_nr, axmap_isset_fn, NULL);
 
-               fio_mutex_down(&axmap->lock);
-               ret = axmap_handler_topdown(axmap, bit_nr, axmap_isset_fn, NULL);
-               fio_mutex_up(&axmap->lock);
-               return ret;
-       }
-
-       return 0;
+       return false;
 }
 
 static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
@@ -389,15 +376,10 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 
 static uint64_t axmap_first_free(struct axmap *axmap)
 {
-       uint64_t ret;
+       if (!firstfree_valid(axmap))
+               axmap->first_free = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
 
-       if (firstfree_valid(axmap))
-               return axmap->first_free;
-
-       ret = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
-       axmap->first_free = ret;
-
-       return ret;
+       return axmap->first_free;
 }
 
 struct axmap_next_free_data {
@@ -406,23 +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;
 }
 
 /*
@@ -433,17 +415,11 @@ uint64_t axmap_next_free(struct axmap *axmap, uint64_t bit_nr)
        struct axmap_next_free_data data = { .level = -1U, .bit = bit_nr, };
        uint64_t ret;
 
-       fio_mutex_down(&axmap->lock);
-
-       if (firstfree_valid(axmap) && bit_nr < axmap->first_free) {
-               ret = axmap->first_free;
-               goto done;
-       }
+       if (firstfree_valid(axmap) && bit_nr < axmap->first_free)
+               return axmap->first_free;
 
-       if (!axmap_handler(axmap, bit_nr, axmap_next_free_fn, &data)) {
-               ret = axmap_first_free(axmap);
-               goto done;
-       }
+       if (!axmap_handler(axmap, bit_nr, axmap_next_free_fn, &data))
+               return axmap_first_free(axmap);
 
        assert(data.level != -1U);
 
@@ -453,12 +429,8 @@ uint64_t axmap_next_free(struct axmap *axmap, uint64_t bit_nr)
         * find the first free one, the map is practically full.
         */
        ret = axmap_find_first_free(axmap, data.level, data.offset);
-       if (ret != -1ULL) {
-done:
-               fio_mutex_up(&axmap->lock);
+       if (ret != -1ULL)
                return ret;
-       }
 
-       ret = axmap_first_free(axmap);
-       goto done;
+       return axmap_first_free(axmap);
 }