squashfsTools: 4.6.1 -> 4.7

This patch is an old patch; see below for the original message body. The patch

has been updated several times to be compatible with new releases.

 * To apply to squashfs 4.4, commit 52eb4c279cd283ed9802dd1ceb686560b22ffb67.

 * To apply to squashfs 4.5, commit 0496d7c3de3e09da37ba492081c86159806ebb07.

 * To apply to squashfs 4.6, commit f7623b3d9953a1190fec181708c9489ef3522b9f.

From af8a6dca694ddd38d8a775a2b5f9a24fe2d10153 Mon Sep 17 00:00:00 2001

From: Amin Hassani <ahassani@google.com>

Date: Thu, 15 Dec 2016 10:43:15 -0800

Subject: [PATCH] mksquashfs 4K aligns the files inside the squashfs image

Files inside a squashfs image are not necessarily 4k (4096)

aligned. This patch starts each file in a 4k aligned address and pads

zero to the end of the file until it reaches the next 4k aligned

address. This will not change the size of the compressed

blocks (especially the last one) and hence it will not change how the

files are being loaded in kernel or unsquashfs. However on average this

increases the size of the squashfs image which can be calculated by the

following formula:

increased_size = (number_of_unfragmented_files_in_image + number of fragments) * 2048

The 4k alignment can be enabled by flag '-4k-align'

---

 squashfs-tools/mksquashfs.c | 16 ++++++++++++++++

 1 file changed, 16 insertions(+)

diff --git a/squashfs-tools/mksquashfs.c b/squashfs-tools/mksquashfs.c

index 3429aac..db164c2 100644

--- a/squashfs-tools/mksquashfs.c

+++ b/squashfs-tools/mksquashfs.c

@@ -82,6 +82,8 @@ int noI = FALSE;

 int noId = FALSE;

 int noD = FALSE;

 int noX = FALSE;

+int do_4k_align = FALSE;

+#define ALIGN_UP(bytes, size) (bytes = (bytes + size - 1) & ~(size - 1))

 /* block size used to build filesystem */

 int block_size = SQUASHFS_FILE_SIZE;

@@ -1624,6 +1626,9 @@ static void unlock_fragments()

 	 * queue at this time.

 	 */

 	while(!queue_empty(locked_fragment)) {

+		// 4k align the start of remaining queued fragments.

+		if(do_4k_align)

+			ALIGN_UP(bytes, 4096);

 		write_buffer = queue_get(locked_fragment);

 		frg = write_buffer->block;	

 		size = SQUASHFS_COMPRESSED_SIZE_BLOCK(fragment_table[frg].size);

@@ -2627,6 +2632,9 @@ static void *frag_deflator(void *arg)

 		write_buffer->size = compressed_size;

 		pthread_mutex_lock(&fragment_mutex);

 		if(fragments_locked == FALSE) {

+			// 4k align the start of each fragment.

+			if(do_4k_align)

+				ALIGN_UP(bytes, 4096);

 			fragment_table[file_buffer->block].size = c_byte;

 			fragment_table[file_buffer->block].start_block = bytes;

 			write_buffer->block = bytes;

@@ -3021,6 +3029,10 @@ static struct file_info *write_file_blocks(int *status, struct dir_ent *dir_ent,

 	struct file_info *file;

 	int bl_hash = 0;

+	// 4k align the start of each file.

+	if(do_4k_align)

+		ALIGN_UP(bytes, 4096);

+

 	if(pre_duplicate(read_size, dir_ent->inode, read_buffer, &bl_hash))

 		return write_file_blocks_dup(status, dir_ent, read_buffer, dup, bl_hash);

@@ -6169,6 +6181,7 @@ static void print_options(FILE *stream, char *name, int total_mem)

 	fprintf(stream, "or metadata.  This is\n\t\t\tequivalent to ");

 	fprintf(stream, "specifying -noI -noD -noF and -noX\n");

 	fprintf(stream, "\nFilesystem build options:\n");

+	fprintf(stream, "-4k-align\t\tenables 4k alignment of all files\n");

 	fprintf(stream, "-tar\t\t\tread uncompressed tar file from standard in (stdin)\n");

 	fprintf(stream, "-no-strip\t\tact like tar, and do not strip leading ");

 	fprintf(stream, "directories\n\t\t\tfrom source files\n");

@@ -6690,6 +6703,7 @@ static void print_summary()

 		"compressed", no_fragments ? "no" : noF ? "uncompressed" :

 		"compressed", no_xattrs ? "no" : noX ? "uncompressed" :

 		"compressed", noI || noId ? "uncompressed" : "compressed");

+	printf("\t4k %saligned\n", do_4k_align ? "" : "un");

 	printf("\tduplicates are %sremoved\n", duplicate_checking ? "" :

 		"not ");

 	printf("Filesystem size %.2f Kbytes (%.2f Mbytes)\n", bytes / 1024.0,

@@ -8417,6 +8431,8 @@ print_compressor_options:

 		} else if(strcmp(argv[i], "-comp") == 0) {

 			/* parsed previously */

 			i++;

+		} else if(strcmp(argv[i], "-4k-align") == 0) {

+			do_4k_align = TRUE;

 		} else {

 			ERROR("%s: invalid option\n\n", argv[0]);

 			print_options(stderr, argv[0], total_mem);

-- 

2.39.2

stdenv.mkDerivation rec {

  pname = "squashfs";

  version = "4.6.1";

  version = "4.7";

  src = fetchFromGitHub {

    owner = "plougher";

    repo = "squashfs-tools";

    rev = version;

    hash = "sha256-fJ+Ijg0cj92abGe80+1swVeZamarVpnPYM7+izcPJ+k=";

    hash = "sha256-hiXpnhMHbDYDy3GT1QGIq4CuH//V5Hp0zhq8JZ6+IdQ=";

  };

  patches = [

    # This patch adds an option to pad filesystems (increasing size) in

    # exchange for better chunking / binary diff calculation.

    ./4k-align.patch

  ];

  strictDeps = true;

  nativeBuildInputs = [

    which