Pack file data and fragments

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 214 insertions, 0 deletions

diff --git a/mkfs/block.c b/mkfs/block.c
new file mode 100644
index 0000000..d68c0c7
--- /dev/null
+++ b/mkfs/block.c
@@ -0,0 +1,214 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "mksquashfs.h"
+#include "util.h"
+
+static int write_block(file_info_t *fi, sqfs_info_t *info)
+{
+	size_t idx, bs;
+	ssize_t ret;
+
+	idx = info->file_block_count++;
+	bs = info->super.block_size;
+
+	ret = info->cmp->do_block(info->cmp, info->block, bs);
+	if (ret < 0)
+		return -1;
+
+	if (ret > 0) {
+		bs = ret;
+		fi->blocksizes[idx] = bs;
+	} else {
+		fi->blocksizes[idx] = bs | (1 << 24);
+	}
+
+	ret = write_retry(info->outfd, info->block, bs);
+	if (ret < 0) {
+		perror("writing to output file");
+		return -1;
+	}
+
+	if ((size_t)ret < bs) {
+		fputs("write to output file truncated\n", stderr);
+		return -1;
+	}
+
+	info->super.bytes_used += bs;
+	return 0;
+}
+
+static int flush_fragments(sqfs_info_t *info)
+{
+	size_t newsz, size;
+	file_info_t *fi;
+	uint64_t offset;
+	ssize_t ret;
+	void *new;
+
+	if (info->num_fragments == info->max_fragments) {
+		newsz = info->max_fragments ? info->max_fragments * 2 : 16;
+		new = realloc(info->fragments,
+			      sizeof(info->fragments[0]) * newsz);
+
+		if (new == NULL) {
+			perror("appending to fragment table");
+			return -1;
+		}
+
+		info->max_fragments = newsz;
+		info->fragments = new;
+	}
+
+	offset = info->super.bytes_used;
+	size = info->frag_offset;
+
+	for (fi = info->frag_list; fi != NULL; fi = fi->frag_next)
+		fi->fragment = info->num_fragments;
+
+	ret = info->cmp->do_block(info->cmp, info->fragment, size);
+	if (ret < 0)
+		return -1;
+
+	info->fragments[info->num_fragments].start_offset = htole64(offset);
+	info->fragments[info->num_fragments].pad0 = 0;
+
+	if (ret > 0) {
+		size = ret;
+		info->fragments[info->num_fragments].size = htole32(size);
+	} else {
+		info->fragments[info->num_fragments].size =
+			htole32(size | (1 << 24));
+	}
+
+	info->num_fragments += 1;
+
+	ret = write_retry(info->outfd, info->fragment, size);
+	if (ret < 0) {
+		perror("writing to output file");
+		return -1;
+	}
+
+	if ((size_t)ret < size) {
+		fputs("write to output file truncated\n", stderr);
+		return -1;
+	}
+
+	memset(info->fragment, 0, info->super.block_size);
+
+	info->super.bytes_used += size;
+	info->frag_offset = 0;
+	info->frag_list = NULL;
+
+	info->super.flags &= ~SQFS_FLAG_NO_FRAGMENTS;
+	info->super.flags |= SQFS_FLAG_ALWAYS_FRAGMENTS;
+	return 0;
+}
+
+static int add_fragment(file_info_t *fi, sqfs_info_t *info, size_t size)
+{
+	if (info->frag_offset + size > info->super.block_size) {
+		if (flush_fragments(info))
+			return -1;
+	}
+
+	fi->fragment_offset = info->frag_offset;
+	fi->frag_next = info->frag_list;
+	info->frag_list = fi;
+
+	memcpy((char *)info->fragment + info->frag_offset, info->block, size);
+	info->frag_offset += size;
+	return 0;
+}
+
+static int process_file(sqfs_info_t *info, file_info_t *fi)
+{
+	uint64_t count = fi->size;
+	int infd, ret;
+	size_t diff;
+
+	infd = open(fi->input_file, O_RDONLY);
+	if (infd < 0) {
+		perror(fi->input_file);
+		return -1;
+	}
+
+	fi->startblock = info->super.bytes_used;
+	info->file_block_count = 0;
+
+	while (count != 0) {
+		diff = count > (uint64_t)info->super.block_size ?
+			info->super.block_size : count;
+
+		ret = read_retry(infd, info->block, diff);
+		if (ret < 0)
+			goto fail_read;
+		if ((size_t)ret < diff)
+			goto fail_trunc;
+
+		if (diff < info->super.block_size) {
+			if (add_fragment(fi, info, diff))
+				goto fail;
+		} else {
+			if (write_block(fi, info))
+				goto fail;
+		}
+
+		count -= diff;
+	}
+
+	close(infd);
+	return 0;
+fail:
+	close(infd);
+	return -1;
+fail_read:
+	fprintf(stderr, "read from %s: %s\n", fi->input_file, strerror(errno));
+	goto fail;
+fail_trunc:
+	fprintf(stderr, "%s: truncated read\n", fi->input_file);
+	goto fail;
+}
+
+static int find_and_process_files(sqfs_info_t *info, tree_node_t *n)
+{
+	if (S_ISDIR(n->mode)) {
+		for (n = n->data.dir->children; n != NULL; n = n->next) {
+			if (find_and_process_files(info, n))
+				return -1;
+		}
+		return 0;
+	}
+
+	if (S_ISREG(n->mode))
+		return process_file(info, n->data.file);
+
+	return 0;
+}
+
+int write_data_to_image(sqfs_info_t *info)
+{
+	int ret;
+
+	info->block = malloc(info->super.block_size);
+
+	if (info->block == NULL) {
+		perror("allocating data block buffer");
+		return -1;
+	}
+
+	info->fragment = malloc(info->super.block_size);
+
+	if (info->fragment == NULL) {
+		perror("allocating fragment buffer");
+		free(info->block);
+		return -1;
+	}
+
+	ret = find_and_process_files(info, info->fs.root);
+
+	free(info->block);
+	free(info->fragment);
+
+	info->block = NULL;
+	info->fragment = NULL;
+	return ret;
+}