:: commit b842720a706b846eeb1110768524829e58502de9
FAT32: support directory entries larger than 1 sector There was already a support for partitions with bigger cluster sizes but there was also a bug where the directory loading code would only look at the first sector of each cluster and could incorrectly report some files as non-existing.
diff --git a/Makefile b/Makefile
index 031a9863..0ec5e4ef 100644
--- a/Makefile
+++ b/Makefile
@@ -62,3 +62,35 @@ fat32-test: all
rm -rf test_image loopback_dev
./qloader2-install src/qloader2.bin test.img 2048
qemu-system-x86_64 -hda test.img -debugcon stdio
+
+fat32-test-big-clusters: all
+ $(MAKE) -C test
+ rm -rf test.img test_image/
+ mkdir test_image
+
+ # Setup partitions
+ dd if=/dev/zero bs=1M count=0 seek=512 of=test.img
+ parted -s test.img mklabel gpt
+ parted -s test.img mkpart primary 2048s 6143s
+ parted -s test.img mkpart primary 6144s 1042432s
+
+ sudo losetup -Pf --show test.img > loopback_dev
+ sudo partprobe `cat loopback_dev`
+ sudo mkfs.fat -s 8 -F 32 `cat loopback_dev`p2
+ sudo mount `cat loopback_dev`p2 test_image
+ sudo mkdir test_image/boot
+
+ # Copy some random files to fill up the fats to span multiple clusters.
+ # This will make the test more credible.
+ sudo find ./src -type f -exec cp -n {} test_image/ \;
+ sudo find ./src -type f -exec cp -n {} test_image/boot/ \;
+
+ # Copy the actual important files
+ sudo cp test/test.elf test_image/boot/
+ sudo cp test/qloader2.cfg test_image/
+ sync
+ sudo umount test_image/
+ sudo losetup -d `cat loopback_dev`
+ rm -rf test_image loopback_dev
+ ./qloader2-install src/qloader2.bin test.img 2048
+ qemu-system-x86_64 -hda test.img -debugcon stdio
diff --git a/src/fs/fat32.c b/src/fs/fat32.c
index d2183cb8..208c6002 100644
--- a/src/fs/fat32.c
+++ b/src/fs/fat32.c
@@ -128,57 +128,59 @@ static int fat32_open_in(struct fat32_context* context, struct fat32_directory_e
bool has_lfn = false;
do {
- struct fat32_directory_entry directory_entries[FAT32_SECTOR_SIZE / sizeof(struct fat32_directory_entry)];
- error = fat32_load_fat_cluster_to_memory(context, current_cluster_number, directory_entries, 0, sizeof(directory_entries));
+ for (size_t sector_in_cluster = 0; sector_in_cluster < context->sectors_per_cluster; sector_in_cluster++) {
+ struct fat32_directory_entry directory_entries[FAT32_SECTOR_SIZE / sizeof(struct fat32_directory_entry)];
+ error = fat32_load_fat_cluster_to_memory(context, current_cluster_number, directory_entries, 0 * FAT32_SECTOR_SIZE, sizeof(directory_entries));
- if (error != 0) {
- return error;
- }
-
- for (unsigned int i = 0; i < SIZEOF_ARRAY(directory_entries); i++) {
- if (directory_entries[i].file_name_and_ext[0] == 0x00) {
- // no more entries here
- break;
+ if (error != 0) {
+ return error;
}
- if (directory_entries[i].attribute == FAT32_LFN_ATTRIBUTE) {
- has_lfn = true;
+ for (unsigned int i = 0; i < SIZEOF_ARRAY(directory_entries); i++) {
+ if (directory_entries[i].file_name_and_ext[0] == 0x00) {
+ // no more entries here
+ break;
+ }
- struct fat32_lfn_entry* lfn = (struct fat32_lfn_entry*) &directory_entries[i];
+ if (directory_entries[i].attribute == FAT32_LFN_ATTRIBUTE) {
+ has_lfn = true;
- if (lfn->sequence_number & 0b01000000) {
- // this lfn is the first entry in the table, clear the lfn buffer
- memset(current_lfn, ' ', sizeof(current_lfn));
- }
+ struct fat32_lfn_entry* lfn = (struct fat32_lfn_entry*) &directory_entries[i];
+
+ if (lfn->sequence_number & 0b01000000) {
+ // this lfn is the first entry in the table, clear the lfn buffer
+ memset(current_lfn, ' ', sizeof(current_lfn));
+ }
- const unsigned int lfn_index = ((lfn->sequence_number & 0b00011111) - 1U) * 13U;
- if (lfn_index >= FAT32_LFN_MAX_ENTRIES * 13) {
+ const unsigned int lfn_index = ((lfn->sequence_number & 0b00011111) - 1U) * 13U;
+ if (lfn_index >= FAT32_LFN_MAX_ENTRIES * 13) {
+ continue;
+ }
+
+ fat32_lfncpy(current_lfn + lfn_index + 00, lfn->name1, 5);
+ fat32_lfncpy(current_lfn + lfn_index + 05, lfn->name2, 6);
+ fat32_lfncpy(current_lfn + lfn_index + 11, lfn->name3, 2);
continue;
}
- fat32_lfncpy(current_lfn + lfn_index + 00, lfn->name1, 5);
- fat32_lfncpy(current_lfn + lfn_index + 05, lfn->name2, 6);
- fat32_lfncpy(current_lfn + lfn_index + 11, lfn->name3, 2);
- continue;
- }
-
- if (has_lfn) {
- // remove trailing spaces
- for (int j = SIZEOF_ARRAY(current_lfn) - 2; j >= -1; j--) {
- if (j == -1 || current_lfn[j] != ' ') {
- current_lfn[j + 1] = 0;
- break;
+ if (has_lfn) {
+ // remove trailing spaces
+ for (int j = SIZEOF_ARRAY(current_lfn) - 2; j >= -1; j--) {
+ if (j == -1 || current_lfn[j] != ' ') {
+ current_lfn[j + 1] = 0;
+ break;
+ }
}
}
- }
- if ((has_lfn && strcmp(current_lfn, name) == 0) || strncmp(directory_entries[i].file_name_and_ext, name, 8 + 3) == 0) {
- *file = directory_entries[i];
- return 0;
- }
+ if ((has_lfn && strcmp(current_lfn, name) == 0) || strncmp(directory_entries[i].file_name_and_ext, name, 8 + 3) == 0) {
+ *file = directory_entries[i];
+ return 0;
+ }
- if (has_lfn) {
- has_lfn = false;
+ if (has_lfn) {
+ has_lfn = false;
+ }
}
}
