X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=lib%2Faxmap.c;h=15cd635037a0bdfc565b26c1f2502180eae831af;hb=aa6738a5d03f82424bf23cb308e4986019f14040;hp=df547f346fdca8045716161f8127d7e16ca6fbed;hpb=731ef4c7c0aad1e6717e645595f3454d264b4f2f;p=fio.git

diff --git a/lib/axmap.c b/lib/axmap.c
index df547f34..15cd6350 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.
  *
@@ -48,6 +48,7 @@ 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)
@@ -103,6 +104,7 @@ struct axmap *axmap_new(unsigned long nr_bits)
 
 	axmap->nr_levels = levels;
 	axmap->levels = smalloc(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];
@@ -187,7 +189,6 @@ void axmap_clear(struct axmap *axmap, uint64_t bit_nr)
 struct axmap_set_data {
 	unsigned int nr_bits;
 	unsigned int set_bits;
-	unsigned int fail_ok;
 };
 
 static unsigned long bit_masks[] = {
@@ -227,10 +228,8 @@ 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);
+	if (overlap == mask)
 		return 1;
-	}
 
 	while (overlap) {
 		unsigned long clear_mask = ~(1UL << ffz(~overlap));
@@ -261,19 +260,24 @@ 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;
@@ -288,10 +292,27 @@ void axmap_set(struct axmap *axmap, uint64_t bit_nr)
 
 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,
@@ -302,7 +323,10 @@ static int axmap_isset_fn(struct axmap_level *al, unsigned long offset,
 
 int 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 0;
 }
 
 static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
@@ -339,7 +363,10 @@ static uint64_t axmap_find_first_free(struct axmap *axmap, unsigned int level,
 		}
 	}
 
-	return ret;
+	if (ret < axmap->nr_bits)
+		return ret;
+
+	return (uint64_t) -1ULL;
 }
 
 uint64_t axmap_first_free(struct axmap *axmap)
@@ -361,9 +388,9 @@ static int 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]))
+	if (!(mask & ~al->map[offset]))
 		return 0;
 
 	if (al->map[offset] != -1UL) {
@@ -382,6 +409,7 @@ 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;
@@ -391,5 +419,14 @@ 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);
 }