X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;ds=sidebyside;f=lib%2Faxmap.c;h=bf203dfe7b2d0ba379ee09b06a6924c3bd00fd03;hb=08bdeb50f763aa3cb8b910a4cff3b14f17f076a6;hp=7351e29725f4189b8178d9e6895efdbc276f61c0;hpb=55348b420e618b1c5c50106261437fe948ef2132;p=fio.git

diff --git a/lib/axmap.c b/lib/axmap.c
index 7351e297..bf203dfe 100644
--- 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.
  *
@@ -22,7 +22,6 @@
 
 #include "../arch/arch.h"
 #include "axmap.h"
-#include "../smalloc.h"
 #include "../minmax.h"
 
 #if BITS_PER_LONG == 64
@@ -33,7 +32,7 @@
 #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)
@@ -48,6 +47,7 @@ struct axmap {
 	unsigned int nr_levels;
 	struct axmap_level *levels;
 	uint64_t first_free;
+	uint64_t nr_bits;
 };
 
 static unsigned long ulog64(unsigned long val, unsigned int log)
@@ -79,10 +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);
-	sfree(axmap);
+	free(axmap->levels);
+	free(axmap);
 }
 
 struct axmap *axmap_new(unsigned long nr_bits)
@@ -90,7 +90,7 @@ 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;
 
@@ -102,14 +102,15 @@ struct axmap *axmap_new(unsigned long nr_bits)
 	}
 
 	axmap->nr_levels = levels;
-	axmap->levels = smalloc(axmap->nr_levels * sizeof(struct axmap_level));
+	axmap->levels = malloc(axmap->nr_levels * sizeof(struct axmap_level));
+	axmap->nr_bits = nr_bits;
 
 	for (i = 0; i < axmap->nr_levels; i++) {
 		struct axmap_level *al = &axmap->levels[i];
 
 		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;
 
@@ -121,14 +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);
+	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;
@@ -142,14 +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;
@@ -163,34 +165,36 @@ 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 {
 	unsigned int nr_bits;
 	unsigned int set_bits;
-	unsigned int fail_ok;
 };
 
-static unsigned long bit_masks[] = {
+static const unsigned long bit_masks[] = {
 	0x0000000000000000, 0x0000000000000001, 0x0000000000000003, 0x0000000000000007,
 	0x000000000000000f, 0x000000000000001f, 0x000000000000003f, 0x000000000000007f,
 	0x00000000000000ff, 0x00000000000001ff, 0x00000000000003ff, 0x00000000000007ff,
@@ -212,7 +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;
@@ -227,10 +231,8 @@ static int axmap_set_fn(struct axmap_level *al, unsigned long offset,
 	 * Mask off any potential overlap, only sets contig regions
 	 */
 	overlap = al->map[offset] & mask;
-	if (overlap == mask) {
-		assert(data->fail_ok);
-		return 1;
-	}
+	if (overlap == mask)
+		return true;
 
 	while (overlap) {
 		unsigned long clear_mask = ~(1UL << ffz(~overlap));
@@ -261,19 +263,24 @@ static void __axmap_set(struct axmap *axmap, uint64_t bit_nr,
 	    axmap->first_free < bit_nr + data->nr_bits)
 		axmap->first_free = -1ULL;
 
+	if (bit_nr > axmap->nr_bits)
+		return;
+	else if (bit_nr + nr_bits > axmap->nr_bits)
+		nr_bits = axmap->nr_bits - bit_nr;
+
 	set_bits = 0;
 	while (nr_bits) {
 		axmap_handler(axmap, bit_nr, axmap_set_fn, data);
 		set_bits += data->set_bits;
 
-		if (data->set_bits != (BLOCKS_PER_UNIT - nr_bits))
+		if (!data->set_bits ||
+		    data->set_bits != (BLOCKS_PER_UNIT - nr_bits))
 			break;
 
 		nr_bits -= data->set_bits;
 		bit_nr += data->set_bits;
 
 		data->nr_bits = nr_bits;
-		data->fail_ok = 1;
 	}
 
 	data->set_bits = set_bits;
@@ -286,30 +293,52 @@ 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)
 {
-	struct axmap_set_data data = { .nr_bits = nr_bits, };
+	unsigned int set_bits = 0;
 
-	__axmap_set(axmap, bit_nr, &data);
-	return data.set_bits;
+	do {
+		struct axmap_set_data data = { .nr_bits = nr_bits, };
+		unsigned int max_bits, this_set;
+
+		max_bits = BLOCKS_PER_UNIT - (bit_nr & BLOCKS_PER_UNIT_MASK);
+		if (max_bits < nr_bits)
+			data.nr_bits = max_bits;
+
+		this_set = data.nr_bits;
+		__axmap_set(axmap, bit_nr, &data);
+		set_bits += data.set_bits;
+		if (data.set_bits != this_set)
+			break;
+
+		nr_bits -= data.set_bits;
+		bit_nr += data.set_bits;
+	} while (nr_bits);
+
+	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)
 {
-	return axmap_handler_topdown(axmap, bit_nr, axmap_isset_fn, NULL);
+	if (bit_nr <= axmap->nr_bits)
+		return axmap_handler_topdown(axmap, bit_nr, axmap_isset_fn, NULL);
+
+	return false;
 }
 
 static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 				       uint64_t index)
 {
+	uint64_t ret = -1ULL;
 	unsigned long j;
-	int i, found = 0;
+	int i;
 
 	/*
 	 * Start at the bottom, then converge towards first free bit at the top
@@ -317,8 +346,11 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 	for (i = level; i >= 0; i--) {
 		struct axmap_level *al = &axmap->levels[i];
 
+		/*
+		 * Clear 'ret', this is a bug condition.
+		 */
 		if (index >= al->map_size) {
-			index = -1ULL;
+			ret = -1ULL;
 			break;
 		}
 
@@ -330,21 +362,22 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 			 * First free bit here is our index into the first
 			 * free bit at the next higher level
 			 */
-			index = (j << UNIT_SHIFT) + ffz(al->map[j]);
-			found = 1;
+			ret = index = (j << UNIT_SHIFT) + ffz(al->map[j]);
 			break;
 		}
 	}
 
-	return found ? index : (uint64_t) -1ULL;
+	if (ret < axmap->nr_bits)
+		return ret;
+
+	return (uint64_t) -1ULL;
 }
 
-uint64_t axmap_first_free(struct axmap *axmap)
+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;
 }
 
@@ -354,23 +387,23 @@ 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 = ~((1UL << ((data->bit & BLOCKS_PER_UNIT_MASK) + 1)) - 1);
+	uint64_t mask = ~bit_masks[(data->bit + 1) & BLOCKS_PER_UNIT_MASK];
 
-	if (!(mask & al->map[offset]))
-		return 0;
+	if (!(mask & ~al->map[offset]))
+		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;
 }
 
 /*
@@ -379,6 +412,7 @@ static int axmap_next_free_fn(struct axmap_level *al, unsigned long offset,
 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;
@@ -388,5 +422,14 @@ uint64_t axmap_next_free(struct axmap *axmap, uint64_t bit_nr)
 
 	assert(data.level != -1U);
 
-	return axmap_find_first_free(axmap, data.level, data.offset);
+	/*
+	 * In the rare case that the map is unaligned, we might end up
+	 * finding an offset that's beyond the valid end. For that case,
+	 * find the first free one, the map is practically full.
+	 */
+	ret = axmap_find_first_free(axmap, data.level, data.offset);
+	if (ret != -1ULL)
+		return ret;
+
+	return axmap_first_free(axmap);
 }