mufs: calculate log2_nentries during mount

include/fs/mufs.h

@@ -9,9 +9,10 @@ struct mufs_tree {
 };
 
 struct mufs {
+	struct mufs_tree root;
 	struct flash_dev *dev;
 	uint32_t nblocks;
-	struct mufs_tree root;
+	uint8_t log2_nentries;
 };
 
 int mufs_mount(struct mufs *fs, struct flash_dev *dev);

source/fs/mufs/super.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <bitops.h>
 #include <flash.h>
 
 #include <fs/mufs.h>
@@ -29,6 +30,7 @@ int mufs_mount(struct mufs *fs, struct flash_dev *dev)
 
 	fs->dev = dev;
 	fs->nblocks = super.nblocks;
+	fs->log2_nentries = fs->dev->log2_block_size - ilog2(sizeof(uint32_t));
 
 	fs->root.file_size = super.file_size;
 	fs->root.root = super.root;

source/fs/mufs/tree.c

@@ -14,7 +14,6 @@ static int mufs_do_lookup(struct mufs *fs, uint32_t *page,
 	char data[1 << fs->dev->log2_block_size];
 	uint32_t *table = (uint32_t *)data;
 	size_t index;
-	uint8_t log2_nentries = fs->dev->log2_block_size - ilog2(sizeof(uint32_t));
 
 	if (!base)
 		return -1;
@@ -28,7 +27,7 @@ static int mufs_do_lookup(struct mufs *fs, uint32_t *page,
 		sizeof data) == 0)
 		return -1;
 
-	index = va & ((1 << (log2_nentries * (depth - 1))) - 1);
+	index = va & ((1 << ((depth - 1) * fs->log2_nentries)) - 1);
 
 	if (!table[index]) {
 		if (!alloc || mufs_alloc_block(fs, &table[index]) < 0)
@@ -56,7 +55,6 @@ static int mufs_do_free_page(struct mufs *fs, uint32_t base,
 	char data[1 << fs->dev->log2_block_size];
 	uint32_t *table = (uint32_t *)data;
 	size_t index;
-	uint8_t log2_nentries = fs->dev->log2_block_size - ilog2(sizeof(uint32_t));
 
 	if (!base)
 		return -1;
@@ -70,14 +68,14 @@ static int mufs_do_free_page(struct mufs *fs, uint32_t base,
 		sizeof data) == 0)
 		return -1;
 
-	index = va & ((1 << (log2_nentries * (depth - 1))) - 1);
+	index = va & ((1 << (fs->log2_nentries * (depth - 1))) - 1);
 
 	if (mufs_do_free_page(fs, table[index], depth - 1, va) < 0)
 		return -1;
 
 	table[index] = 0;
 
-	for (index = 0; index < (UINT32_C(1) << log2_nentries); ++index) {
+	for (index = 0; index < (UINT32_C(1) << fs->log2_nentries); ++index) {
 		if (!table[index])
 			continue;
 
@@ -123,18 +121,17 @@ int mufs_shrink_tree(struct mufs *fs, struct mufs_tree *tree, uint32_t max_size)
 	uint32_t *table = (uint32_t *)data;
 	size_t index;
 	uint32_t base, size;
-	uint8_t log2_nentries = fs->dev->log2_block_size - ilog2(sizeof(uint32_t));
 	uint8_t depth;
 
 	base = tree->root;
 
 	for (depth = tree->depth; depth; --depth) {
-		size = 1 << (depth * log2_nentries + fs->dev->log2_block_size);
+		size = 1 << (depth * fs->log2_nentries + fs->dev->log2_block_size);
 
 		if (size < max_size)
 			return 0;
 
-		index = max_size >> ((depth - 1) * log2_nentries +
+		index = max_size >> ((depth - 1) * fs->log2_nentries +
 			fs->dev->log2_block_size);
 
 		if (flash_read(fs->dev, base, data, sizeof data) == 0)
@@ -149,7 +146,7 @@ int mufs_shrink_tree(struct mufs *fs, struct mufs_tree *tree, uint32_t max_size)
 			continue;
 		}
 
-		for (; index < (UINT32_C(1) << log2_nentries); ++index) {
+		for (; index < (UINT32_C(1) << fs->log2_nentries); ++index) {
 			table[index] = 0;
 		}