Skip to content
Permalink

Comparing changes

Choose two branches to see what’s changed or to start a new pull request. If you need to, you can also or learn more about diff comparisons.

Open a pull request

Create a new pull request by comparing changes across two branches. If you need to, you can also . Learn more about diff comparisons here.
base repository: NixOS/nixpkgs
Failed to load repositories. Confirm that selected base ref is valid, then try again.
Loading
base: c102306c1f4b
Choose a base ref
...
head repository: NixOS/nixpkgs
Failed to load repositories. Confirm that selected head ref is valid, then try again.
Loading
compare: 9eefb443f34a
Choose a head ref
  • 1 commit
  • 2 files changed
  • 1 contributor

Commits on Nov 17, 2018

  1. squashfsTools: incorporate 4k-alignment option patch (#49200)

    @charles-dyfis-net @Mic92
    charles-dyfis-net authored and Mic92 committed Nov 17, 2018

    Unverified

    This commit is not signed, but one or more authors requires that any commit attributed to them is signed.
    Learn about vigilant mode
    Copy the full SHA
    9eefb44 View commit details
Showing with 99 additions and 3 deletions.
  1. +7 −3 pkgs/tools/filesystems/squashfs/default.nix
  2. +92 −0 pkgs/tools/filesystems/squashfs/squashfs-tools-4.3-4k-align.patch
10 changes: 7 additions & 3 deletions pkgs/tools/filesystems/squashfs/default.nix
View file
Original file line number Diff line number Diff line change
@@ -15,13 +15,17 @@ stdenv.mkDerivation rec {
rev = "9c1db6d13a51a2e009f0027ef336ce03624eac0d";
};

# These patches ensures that mksquashfs output is reproducible.
# See also https://reproducible-builds.org/docs/system-images/
# and https://github.com/NixOS/nixpkgs/issues/40144.
patches = [
# These patches ensures that mksquashfs output is reproducible.
# See also https://reproducible-builds.org/docs/system-images/
# and https://github.com/NixOS/nixpkgs/issues/40144.
./0001-If-SOURCE_DATE_EPOCH-is-set-override-timestamps-with.patch
./0002-If-SOURCE_DATE_EPOCH-is-set-also-clamp-content-times.patch
./0003-remove-frag-deflator-thread.patch

# This patch adds an option to pad filesystems (increasing size) in
# exchange for better chunking / binary diff calculation.
./squashfs-tools-4.3-4k-align.patch
] ++ stdenv.lib.optional stdenv.isDarwin ./darwin.patch;

buildInputs = [ zlib xz ]
92 changes: 92 additions & 0 deletions pkgs/tools/filesystems/squashfs/squashfs-tools-4.3-4k-align.patch
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,92 @@
From 7bda7c75748f36b0a50f93e46144d5a4de4974ad 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 8b1376f..683973d 100644
--- a/squashfs-tools/mksquashfs.c
+++ b/squashfs-tools/mksquashfs.c
@@ -99,6 +99,8 @@ int old_exclude = TRUE;
int use_regex = FALSE;
int nopad = FALSE;
int exit_on_error = FALSE;
+int do_4k_align = FALSE;
+#define ALIGN_UP(bytes, size) (bytes = (bytes + size - 1) & ~(size - 1))

long long global_uid = -1, global_gid = -1;

@@ -1513,6 +1515,9 @@ 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);
@@ -2420,6 +2420,9 @@
compressed_size = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte);
write_buffer->size = compressed_size;
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;
@@ -2761,6 +2769,10 @@ int write_file_blocks(squashfs_inode *inode, struct dir_ent *dir_ent,
long long sparse = 0;
struct file_buffer *fragment_buffer = NULL;

+ // 4k align the start of each file.
+ if(do_4k_align)
+ ALIGN_UP(bytes, 4096);
+
if(pre_duplicate(read_size))
return write_file_blocks_dup(inode, dir_ent, read_buffer, dup);

@@ -4692,6 +4704,7 @@ void write_filesystem_tables(struct squashfs_super_block *sBlk, int nopad)
"compressed", no_fragments ? "no" : noF ? "uncompressed" :
"compressed", no_xattrs ? "no" : noX ? "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,
@@ -5346,6 +5359,8 @@ print_compressor_options:
root_name = argv[i];
} else if(strcmp(argv[i], "-version") == 0) {
VERSION();
+ } else if(strcmp(argv[i], "-4k-align") == 0) {
+ do_4k_align = TRUE;
} else {
ERROR("%s: invalid option\n\n", argv[0]);
printOptions:
@@ -5387,6 +5402,7 @@ printOptions:
ERROR("\t\t\tdirectory containing that directory, "
"rather than the\n");
ERROR("\t\t\tcontents of the directory\n");
+ ERROR("-4k-align\t\tenables 4k alignment of all files\n");
ERROR("\nFilesystem filter options:\n");
ERROR("-p <pseudo-definition>\tAdd pseudo file "
"definition\n");
--
2.14.1.480.gb18f417b89-goog (previously; hand-patched by charles-dyfis-net)