libflash/libffs: Switch to storing header entries in an array

Since the libffs no longer needs to sort the entries as they get added
it makes little sense to have the complexity of a linked list when an
array will suffice.

Signed-off-by: Cyril Bur <cyril.bur@au1.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

1 files changed, 65 insertions, 63 deletions

diff --git a/libflash/libffs.c b/libflash/libffs.c
index 6c30e09..d295280 100644
--- a/libflash/libffs.c
+++ b/libflash/libffs.c
@@ -36,6 +36,7 @@ static void *calloc(size_t num, size_t size)
 #include "ffs.h"
 
 #define __unused __attribute__((unused))
+#define HDR_ENTRIES_NUM 30
 
 struct ffs_handle {
 	struct ffs_hdr		hdr;	/* Converted header */
@@ -73,13 +74,9 @@ static size_t ffs_hdr_raw_size(int num_entries)
 
 static int ffs_num_entries(struct ffs_hdr *hdr)
 {
-	struct ffs_entry *ent;
-	int num_entries = 0;
-	list_for_each(&hdr->entries, ent, list)
-		num_entries++;
-	if (num_entries == 0)
+	if (hdr->count == 0)
 		FL_DBG("%s returned zero!\n", __func__);
-	return num_entries;
+	return hdr->count;
 }
 
 static int ffs_check_convert_header(struct ffs_hdr *dst, struct __ffs_hdr *src)
@@ -100,6 +97,7 @@ static int ffs_check_convert_header(struct ffs_hdr *dst, struct __ffs_hdr *src)
 	dst->block_size = be32_to_cpu(src->block_size);
 	dst->size = be32_to_cpu(src->size) * dst->block_size;
 	dst->block_count = be32_to_cpu(src->block_count);
+	dst->entries_size = be32_to_cpu(src->entry_count);
 
 	return 0;
 }
@@ -129,21 +127,16 @@ static int ffs_entry_user_to_cpu(struct ffs_hdr *hdr __unused,
 static int ffs_entry_to_flash(struct ffs_hdr *hdr,
 		struct __ffs_entry *dst, struct ffs_entry *src)
 {
-	int rc, index = 1; /* On flash indexes start at 1 */
-	struct ffs_entry *ent = NULL;
+	int rc, index;
 
 	if (!hdr || !dst || !src)
 		return -1;
 
-	list_for_each(&hdr->entries, ent, list) {
-		if (ent == src)
-			break;
-		index++;
-	}
+	for (index = 0; index < hdr->count && hdr->entries[index] != src; index++);
 
-	if (!ent)
+	if (index == hdr->count)
 		return FFS_ERR_PART_NOT_FOUND;
-
+	index++; /* On flash indexes start at 1 */
 	/*
 	 * So that the checksum gets calculated correctly at least the
 	 * dst->checksum must be zero before calling ffs_entry_checksum()
@@ -289,15 +282,9 @@ bool has_flag(struct ffs_entry *ent, uint16_t flag)
 
 struct ffs_entry *ffs_entry_get(struct ffs_handle *ffs, uint32_t index)
 {
-	int i = 0;
-	struct ffs_entry *ent = NULL;
-
-	list_for_each(&ffs->hdr.entries, ent, list)
-		if (i++ == index)
-			return ent;
-
-	/* Didn't find partition */
-	return NULL;
+	if (!ffs || index >= ffs->hdr.count)
+		return NULL;
+	return ffs->hdr.entries[index];
 }
 
 bool has_ecc(struct ffs_entry *ent)
@@ -363,7 +350,6 @@ int ffs_init(uint32_t offset, uint32_t max_size, struct blocklevel_device *bl,
 	f->toc_offset = offset;
 	f->max_size = max_size;
 	f->bl = bl;
-	list_head_init(&f->hdr.entries);
 
 	/* Convert and check flash header */
 	rc = ffs_check_convert_header(&f->hdr, &raw_hdr);
@@ -379,6 +365,8 @@ int ffs_init(uint32_t offset, uint32_t max_size, struct blocklevel_device *bl,
 		goto out;
 	}
 
+	f->hdr.entries = calloc(f->hdr.entries_size, sizeof(struct ffs_entry *));
+
 	/*
 	 * Grab the entire partition header
 	 */
@@ -406,14 +394,14 @@ int ffs_init(uint32_t offset, uint32_t max_size, struct blocklevel_device *bl,
 		goto out;
 	}
 
-	for (i = 0; i < be32_to_cpu(raw_hdr.entry_count); i++) {
+	for (i = 0; i < f->hdr.entries_size; i++) {
 		struct ffs_entry *ent = calloc(1, sizeof(struct ffs_entry));
 		if (!ent) {
 			rc = FLASH_ERR_MALLOC_FAILED;
 			goto out;
 		}
 
-		list_add_tail(&f->hdr.entries, &ent->list);
+		f->hdr.entries[f->hdr.count++] = ent;
 		rc = ffs_entry_to_cpu(&f->hdr, ent, &f->cache->entries[i]);
 		if (rc) {
 			FL_DBG("FFS: Failed checksum for partition %s\n",
@@ -442,20 +430,20 @@ out:
 
 static void __hdr_free(struct ffs_hdr *hdr)
 {
-	struct ffs_entry *ent, *next;
+	int i;
 
-	list_for_each_safe(&hdr->entries, ent, next, list) {
-		list_del(&ent->list);
-		free(ent);
-	}
+	if (!hdr)
+		return;
+
+	for (i = 0; i < hdr->count; i++)
+		free(hdr->entries[i]);
+	free(hdr->entries);
 }
 
 int ffs_hdr_free(struct ffs_hdr *hdr)
 {
-	printf("Freeing hdr\n");
 	__hdr_free(hdr);
 	free(hdr);
-
 	return 0;
 }
 
@@ -472,20 +460,20 @@ void ffs_close(struct ffs_handle *ffs)
 int ffs_lookup_part(struct ffs_handle *ffs, const char *name,
 		    uint32_t *part_idx)
 {
-	struct ffs_entry *ent = NULL;
-	int i = 0, rc = FFS_ERR_PART_NOT_FOUND;
+	struct ffs_entry **ents = ffs->hdr.entries;
+	int i;
 
-	list_for_each(&ffs->hdr.entries, ent, list) {
-		if (strncmp(name, ent->name, sizeof(ent->name)) == 0) {
-			rc = 0;
-			break;
-		}
-		i++;
-	}
+	for (i = 0;
+			i < ffs->hdr.count &&
+			strncmp(name, ents[i]->name, FFS_PART_NAME_MAX);
+			i++);
 
-	if (rc == 0 && part_idx)
+	if (i == ffs->hdr.count)
+		return FFS_ERR_PART_NOT_FOUND;
+
+	if (part_idx)
 		*part_idx = i;
-	return rc;
+	return 0;
 }
 
 int ffs_part_info(struct ffs_handle *ffs, uint32_t part_idx,
@@ -560,19 +548,25 @@ int ffs_next_side(struct ffs_handle *ffs, struct ffs_handle **new_ffs,
 
 int ffs_entry_add(struct ffs_hdr *hdr, struct ffs_entry *entry)
 {
-	struct ffs_entry *ent;
-	uint32_t smallest_base;
 	const char *smallest_name;
-	int count = 0;
-	assert(!list_empty(&hdr->entries));
+	uint32_t smallest_base;
+	int i;
 
+	if (hdr->count == 0) {
+		FL_DBG("Adding an entry to an empty header\n");
+		hdr->entries[hdr->count++] = entry;
+	}
 	if (entry->base + entry->size > hdr->block_size * hdr->block_count)
 		return FFS_ERR_BAD_PART_SIZE;
 
 	smallest_base = entry->base;
 	smallest_name = entry->name;
-	/* Input validate first to a) fail early b) do it all together */
-	list_for_each(&hdr->entries, ent, list) {
+	/*
+	 * TODO: This may have assumed entries was sorted
+	 */
+	for (i = 0; i < hdr->count; i++) {
+		struct ffs_entry *ent = hdr->entries[i];
+
 		/* Don't allow same names to differ only by case */
 		if (strncasecmp(entry->name, ent->name, FFS_PART_NAME_MAX) == 0)
 			return FFS_ERR_BAD_PART_NAME;
@@ -591,14 +585,12 @@ int ffs_entry_add(struct ffs_hdr *hdr, struct ffs_entry *entry)
 			return FFS_ERR_BAD_PART_PID;
 
 		/* Skip the first partition as it IS the partition table */
-		if (ent->base < smallest_base && count > 0) {
+		if (ent->base < smallest_base && i > 0) {
 			smallest_base = ent->base;
 			smallest_name = ent->name;
 		}
-		count++;
 	}
-
-	if ((count + 1) * sizeof(struct __ffs_entry) +
+	if ((hdr->count + 1) * sizeof(struct __ffs_entry) +
 			sizeof(struct __ffs_hdr) > smallest_base) {
 		fprintf(stderr, "Adding partition '%s' would cause partition '%s' at "
 				"0x%08x to overlap with the header\n", entry->name, smallest_name,
@@ -606,7 +598,18 @@ int ffs_entry_add(struct ffs_hdr *hdr, struct ffs_entry *entry)
 		return FFS_ERR_BAD_PART_BASE;
 	}
 
-	list_add_tail(&hdr->entries, &entry->list);
+	if (hdr->count == hdr->entries_size) {
+		struct ffs_entry **old = hdr->entries;
+
+		hdr->entries = realloc(hdr->entries,
+				(HDR_ENTRIES_NUM + hdr->entries_size) * sizeof(struct ffs_entry *));
+		if (!hdr->entries) {
+			hdr->entries = old;
+			return FLASH_ERR_MALLOC_FAILED;
+		}
+		hdr->entries_size += HDR_ENTRIES_NUM;
+	}
+	hdr->entries[hdr->count++] = entry;
 
 	return 0;
 }
@@ -614,7 +617,6 @@ int ffs_entry_add(struct ffs_hdr *hdr, struct ffs_entry *entry)
 int ffs_hdr_finalise(struct blocklevel_device *bl, struct ffs_hdr *hdr)
 {
 	int num_entries, i, rc = 0;
-	struct ffs_entry *ent;
 	struct __ffs_hdr *real_hdr;
 
 	num_entries = ffs_num_entries(hdr);
@@ -650,14 +652,12 @@ int ffs_hdr_finalise(struct blocklevel_device *bl, struct ffs_hdr *hdr)
 	real_hdr->block_count = cpu_to_be32(hdr->block_count);
 	real_hdr->checksum = ffs_hdr_checksum(real_hdr);
 
-	i = 0;
-	list_for_each(&hdr->entries, ent, list) {
-		rc = ffs_entry_to_flash(hdr, real_hdr->entries + i, ent);
+	for (i = 0; i < hdr->count; i++) {
+		rc = ffs_entry_to_flash(hdr, real_hdr->entries + i, hdr->entries[i]);
 		if (rc) {
 			fprintf(stderr, "Couldn't format all entries for new TOC\n");
 			goto out;
 		}
-		i++;
 	}
 
 	/* Don't really care if this fails */
@@ -759,7 +759,8 @@ int ffs_hdr_new(uint32_t block_size, uint32_t block_count, struct ffs_hdr **r)
 	ret->version = FFS_VERSION_1;
 	ret->block_size = block_size;
 	ret->block_count = block_count;
-	list_head_init(&ret->entries);
+	ret->entries = calloc(HDR_ENTRIES_NUM, sizeof(struct ffs_entry *));
+	ret->entries_size = HDR_ENTRIES_NUM;
 
 	/* Don't know how big it will be, ffs_hdr_finalise() will fix */
 	rc = ffs_entry_new("part", 0, 0, &part_table);
@@ -773,7 +774,8 @@ int ffs_hdr_new(uint32_t block_size, uint32_t block_count, struct ffs_hdr **r)
 	part_table->type = FFS_TYPE_PARTITION;
 	part_table->flags = FFS_FLAGS_PROTECTED;
 
-	list_add(&ret->entries, &part_table->list);
+	ret->entries[0] = part_table;
+	ret->count = 1;
 
 	*r = ret;