:: commit ee38f8b4c96cbaf219d63702a6a01e9bbe68ccf6
Improve ext2 inode reading
diff --git a/Makefile b/Makefile
index 5c9adba5..50eeea3e 100644
--- a/Makefile
+++ b/Makefile
@@ -24,16 +24,18 @@ ext2-test: all
rm -rf test.img test_image/
mkdir test_image
dd if=/dev/zero bs=1M count=0 seek=64 of=test.img
- parted -s test.img mklabel msdos
- parted -s test.img mkpart primary 1 100%
+ parted -s test.img mklabel gpt
+ parted -s test.img mkpart primary 2048s 6143s
+ parted -s test.img mkpart primary 6144s 131038s
sudo losetup -Pf --show test.img > loopback_dev
- sudo mkfs.ext2 `cat loopback_dev`p1
- sudo mount `cat loopback_dev`p1 test_image
- sudo cp test/test.elf test_image
- sudo cp test/qloader2.cfg test_image
+ sudo mkfs.ext2 `cat loopback_dev`p2
+ sudo mount `cat loopback_dev`p2 test_image
+ sudo mkdir test_image/boot
+ 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
+ ./qloader2-install src/qloader2.bin test.img 2048
qemu-system-x86_64 -hda test.img -monitor stdio
diff --git a/qloader2.bin b/qloader2.bin
index a20ea0fc..4f543b22 100644
Binary files a/qloader2.bin and b/qloader2.bin differ
diff --git a/src/fs/ext2fs.c b/src/fs/ext2fs.c
index a44bbc25..54fe75a7 100644
--- a/src/fs/ext2fs.c
+++ b/src/fs/ext2fs.c
@@ -185,6 +185,10 @@ struct ext2fs_dir_entry {
uint8_t type; // File type
} __attribute__((packed));
+static int inode_read(void *buf, uint64_t loc, uint64_t count,
+ uint64_t block_size, struct ext2fs_inode *inode,
+ uint64_t drive, struct part *part);
+
// parse an inode given the partition base and inode number
static int ext2fs_get_inode(struct ext2fs_inode *ret, uint64_t drive, struct part *part, uint64_t inode, struct ext2fs_superblock *sb) {
if (inode == 0)
@@ -226,16 +230,17 @@ next:
else
path++;
- uint64_t offset = current_inode->i_blocks[0] * fd->block_size;
-
- uint64_t stop = current_inode->i_size + offset;
- while (offset < stop) {
+ for (uint32_t i = 0; i < current_inode->i_size; ) {
// preliminary read
- read_partition(fd->drive, &fd->part, dir, offset, sizeof(struct ext2fs_dir_entry));
+ inode_read(dir, i, sizeof(struct ext2fs_dir_entry),
+ fd->block_size, current_inode,
+ fd->drive, &fd->part);
// name read
char *name = balloc(dir->name_len);
- read_partition(fd->drive, &fd->part, name, offset + sizeof(struct ext2fs_dir_entry), dir->name_len);
+ inode_read(name, i + sizeof(struct ext2fs_dir_entry), dir->name_len,
+ fd->block_size, current_inode,
+ fd->drive, &fd->part);
int r = strncmp(token, name, dir->name_len);
@@ -252,7 +257,7 @@ next:
}
}
- offset += dir->rec_len;
+ i += dir->rec_len;
}
brewind(sizeof(struct ext2fs_inode));
@@ -284,54 +289,60 @@ int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const
}
int ext2fs_read(struct ext2fs_file_handle *file, void *buf, uint64_t loc, uint64_t count) {
- // TODO: add support for the indirect block pointers
+ return inode_read(buf, loc, count,
+ file->block_size, &file->inode,
+ file->drive, &file->part);
+}
+static int inode_read(void *buf, uint64_t loc, uint64_t count,
+ uint64_t block_size, struct ext2fs_inode *inode,
+ uint64_t drive, struct part *part) {
for (uint64_t progress = 0; progress < count;) {
- uint64_t block = (loc + progress) / file->block_size;
+ uint64_t block = (loc + progress) / block_size;
uint64_t chunk = count - progress;
- uint64_t offset = (loc + progress) % file->block_size;
- if (chunk > file->block_size - offset)
- chunk = file->block_size - offset;
+ uint64_t offset = (loc + progress) % block_size;
+ if (chunk > block_size - offset)
+ chunk = block_size - offset;
uint64_t block_index;
if (block < 12) {
// Direct block
- block_index = file->inode.i_blocks[block];
+ block_index = inode->i_blocks[block];
} else {
// Indirect block
block -= 12;
- if (block * sizeof(uint32_t) >= file->block_size) {
+ if (block * sizeof(uint32_t) >= block_size) {
// Double indirect block
- block -= file->block_size / sizeof(uint32_t);
- uint32_t index = block / (file->block_size / sizeof(uint32_t));
- if (index * sizeof(uint32_t) >= file->block_size) {
+ block -= block_size / sizeof(uint32_t);
+ uint32_t index = block / (block_size / sizeof(uint32_t));
+ if (index * sizeof(uint32_t) >= block_size) {
// Triple indirect block
panic("ext2fs: triply indirect blocks unsupported");
}
- uint32_t offset = block % (file->block_size / sizeof(uint32_t));
+ uint32_t offset = block % (block_size / sizeof(uint32_t));
uint32_t indirect_block;
read_partition(
- file->drive, &file->part, &indirect_block,
- file->inode.i_blocks[13] * file->block_size + index * sizeof(uint32_t),
+ drive, part, &indirect_block,
+ inode->i_blocks[13] * block_size + index * sizeof(uint32_t),
sizeof(uint32_t)
);
read_partition(
- file->drive, &file->part, &block_index,
- indirect_block * file->block_size + offset * sizeof(uint32_t),
+ drive, part, &block_index,
+ indirect_block * block_size + offset * sizeof(uint32_t),
sizeof(uint32_t)
);
} else {
read_partition(
- file->drive, &file->part, &block_index,
- file->inode.i_blocks[12] * file->block_size + block * sizeof(uint32_t),
+ drive, part, &block_index,
+ inode->i_blocks[12] * block_size + block * sizeof(uint32_t),
sizeof(uint32_t)
);
}
}
- read_partition(file->drive, &file->part, buf + progress, (block_index * file->block_size) + offset, chunk);
+ read_partition(drive, part, buf + progress, (block_index * block_size) + offset, chunk);
progress += chunk;
}
