Revert "axmap: fix deadlock"

[fio.git] / lib / axmap.c

diff --git a/lib/axmap.c b/lib/axmap.c
index c9f3a4f1a3b16bcaddfe07b43296e50b6da1bd4c..e847a387bc6b8ab984ca4ca4162183ef37b6dd0f 100644 (file)
--- a/lib/axmap.c
+++ b/lib/axmap.c
@@ -5,7 +5,7 @@
  * nothing to do with anything remotely narcissistic.
  *
  * A set bit at layer N indicates a full word at layer N-1, and so forth. As
- * the bitmap becomes progressively more full, checking for existance
+ * the bitmap becomes progressively more full, checking for existence
  * becomes cheaper (since fewer layers are walked, making it a lot more
  * cache friendly) and locating the next free space likewise.
  *
@@ -23,6 +23,7 @@
 #include "../arch/arch.h"
 #include "axmap.h"
 #include "../smalloc.h"
+#include "../mutex.h"
 #include "../minmax.h"
 
 #if BITS_PER_LONG == 64
@@ -33,7 +34,7 @@
 #error "Number of arch bits unknown"
 #endif
 
-#define BLOCKS_PER_UNIT                (1UL << UNIT_SHIFT)
+#define BLOCKS_PER_UNIT                (1U << UNIT_SHIFT)
 #define BLOCKS_PER_UNIT_MASK   (BLOCKS_PER_UNIT - 1)
 
 #define firstfree_valid(b)     ((b)->first_free != (uint64_t) -1)
@@ -45,6 +46,7 @@ struct axmap_level {
 };
 
 struct axmap {
+       struct fio_mutex lock;
        unsigned int nr_levels;
        struct axmap_level *levels;
        uint64_t first_free;
@@ -63,6 +65,8 @@ 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];
 
@@ -70,6 +74,7 @@ void axmap_reset(struct axmap *axmap)
        }
 
        axmap->first_free = 0;
+       fio_mutex_up(&axmap->lock);
 }
 
 void axmap_free(struct axmap *axmap)
@@ -83,6 +88,7 @@ void axmap_free(struct axmap *axmap)
                sfree(axmap->levels[i].map);
 
        sfree(axmap->levels);
+       __fio_mutex_remove(&axmap->lock);
        sfree(axmap);
 }
 
@@ -95,6 +101,8 @@ struct axmap *axmap_new(unsigned long nr_bits)
        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) {
@@ -126,6 +134,8 @@ err:
                        sfree(axmap->levels[i].map);
 
        sfree(axmap->levels);
+       __fio_mutex_remove(&axmap->lock);
+       sfree(axmap);
        return NULL;
 }
 
@@ -287,7 +297,9 @@ 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)
@@ -323,8 +335,14 @@ static int axmap_isset_fn(struct axmap_level *al, unsigned long offset,
 
 int 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);
+       if (bit_nr <= axmap->nr_bits) {
+               int ret;
+
+               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;
 }
@@ -371,11 +389,17 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 
 uint64_t axmap_first_free(struct axmap *axmap)
 {
+       uint64_t ret;
+
        if (firstfree_valid(axmap))
                return axmap->first_free;
 
-       axmap->first_free = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
-       return axmap->first_free;
+       fio_mutex_down(&axmap->lock);
+       ret = axmap_find_first_free(axmap, axmap->nr_levels - 1, 0);
+       axmap->first_free = ret;
+       fio_mutex_up(&axmap->lock);
+
+       return ret;
 }
 
 struct axmap_next_free_data {
@@ -411,11 +435,17 @@ 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;
 
-       if (firstfree_valid(axmap) && bit_nr < axmap->first_free)
-               return axmap->first_free;
+       fio_mutex_down(&axmap->lock);
 
-       if (!axmap_handler(axmap, bit_nr, axmap_next_free_fn, &data))
-               return axmap_first_free(axmap);
+       if (firstfree_valid(axmap) && bit_nr < axmap->first_free) {
+               ret = axmap->first_free;
+               goto done;
+       }
+
+       if (!axmap_handler(axmap, bit_nr, axmap_next_free_fn, &data)) {
+               ret = axmap_first_free(axmap);
+               goto done;
+       }
 
        assert(data.level != -1U);
 
@@ -425,8 +455,12 @@ 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)
+       if (ret != -1ULL) {
+done:
+               fio_mutex_up(&axmap->lock);
                return ret;
+       }
 
-       return axmap_first_free(axmap);
+       ret = axmap_first_free(axmap);
+       goto done;
 }