1.1.07 release

[Ventoy.git] / SQUASHFS / squashfs-tools-4.4 / CHANGES

                        SQUASHFS CHANGE LOG

4.4     29 AUG 2019     Reproducible builds, new compressors,
                        CVE fixes, security hardening and new options
                        for Mksquashfs/Unsquashfs.

        1. Overall improvements:

                1.1 Mksquashfs now generates reproducible images by default.
                1.2 Mkfs time and file timestamps can also be specified.
                1.3 Support for the Zstandard (ZSTD) compression algorithm.
                1.4 CVE-2015-4645 and CVE-2015-4646 have been fixed.

        2. Mksquashfs improvements and major bug fixes:

                2.1 Pseudo files now support symbolic links.
                2.2 New -mkfs-time option.
                2.3 New -all-time option.
                2.4 New -root-mode option.
                2.5 New -quiet option.
                2.6 New -noId option.
                2.7 New -offset option.
                2.8 Update lz4 wrapper to use new functions introduced
                    in 1.7.0.
                2.9 Bug fix, don't allow "/" pseudo filenames.
                2.10 Bug fix, allow quoting of pseudo files, to
                     better handle filenames with spaces.
                2.11 Fix compilation with glibc 2.25+.

        3. Unsquashfs improvements and major bug fixes:

                3.1 CVE-2015-4645 and CVE-2015-4646 have been fixed.
                3.2 Unsquashfs has been further hardened against corrupted
                    filestems.
                3.3 Unsquashfs is now more strict about error handling.
                3.4 New -ignore-errors option.
                3.5 New -strict-errors option.
                3.6 New -lln[umeric] option.
                3.7 New -lc option.
                3.8 New -llc option.
                3.9 New -mkfs-time option.
                3.10 New -UTC option.
                3.11 New -offset option.
                3.12 New -quiet option.
                3.13 Update lz4 wrapper to use new functions introduced
                     in 1.7.0.
                3.14 Bug fix, fatal and non-fatal errors now set the exit
                     code to 1.
                3.15 Bug fix, fix time setting for symlinks.
                3.16 Bug fix, try to set sticky-bit when running as a
                     user process.
                3.17 Fix compilation with glibc 2.25+.

4.3     12 MAY 2014     New compressor options, new Mksquashfs/Unsquashfs
                        functionality, duplicate checking optimisations,
                        stability improvements (option/file parsing,
                        buffer/memory overflow checks, filesystem hardening
                        on corrupted filesystems), CVE fixes.

        Too many changes to do the traditional custom changelog.  But, this
        is now unnecessary, so instead list most significant 15% of commits
        from git changelog in chronological order.

        - unsquashfs: add checks for corrupted data in opendir functions
        - unsquashfs: completely empty filesystems incorrectly generate an error
        - unsquashfs: fix open file limit
        - mksquashfs: Use linked list to store directory entries rather
        - mksquashfs: Remove qsort and add a bottom up linked list merge sort
        - mksquashfs: optimise lookup_inode2() for dirs
        - pseudo: fix handling of modify pseudo files
        - pseudo: fix handling of directory pseudo files
        - xattr: Fix ERROR() so that it is synchronised with the progress bar
        - mksquashfs/sort: Fix INFO() so that it is synced with the progress bar
        - mksquashfs: Add -progress to force progress bar when using -info
        - error.h: consolidate the various error macros into one header file
        - mksquashfs: fix stack overflow in write_fragment_table()
        - mksquashfs: move list allocation from off the stack
        - unsquashfs: fix oversight in directory permission setting
        - mksquashfs: dynamically allocate recovery_file
        - mksquashfs: dynamically allocate buffer in subpathname()
        - mksquashfs: dynamically allocate buffer in pathname()
        - unsquashfs: fix CVE-2012-4024
        - unsquashfs: fix CVE-2012-4025
        - mksquashfs: fix potential stack overflow in get_component()
        - mksquashfs: add parse_number() helper for numeric command line options
        - mksquasfs: check return value of fstat() in reader_read_file()
        - mksquashfs: dynamically allocate filename in old_add_exclude()
        - unsquashfs: dynamically allocate pathname in dir_scan()
        - unsquashfs: dynamically allocate pathname in pre_scan()
        - sort: dynamically allocate filename in add_sort_list()
        - mksquashfs: fix dir_scan() exit if lstat of source directory fails
        - pseudo: fix memory leak in read_pseudo_def() if exec_file() fails
        - pseudo: dynamically allocate path in dump_pseudo()
        - mksquashfs: dynamically allocate path in display_path2()
        - mksquashfs: dynamically allocate b_buffer in getbase()
        - pseudo: fix potential stack overflow in get_component()
        - pseudo: avoid buffer overflow in read_pseudo_def() using sscanf()
        - pseudo: dynamically allocate filename in exec_file()
        - pseudo: avoid buffer overflow in read_sort_file() using fscanf()
        - sort: tighten up sort file parsing
        - unsquashfs: fix name under-allocation in process_extract_files()
        - unsquashfs: avoid buffer overflow in print_filename() using sprintf()
        - Fix some limits in the file parsing routines
        - pseudo: Rewrite pseudo file processing
        - read_fs: fix small memory leaks in read_filesystem()
        - mksquashfs: fix fclose leak in reader_read_file() on I/O error
        - mksquashfs: fix frag struct leak in write_file_{process|blocks|frag}
        - unsquashfs_xattr: fix memory leak in write_xattr()
        - read_xattrs: fix xattr free in get_xattr() in error path
        - unsquashfs: add -user-xattrs option to only extract user.xxx xattrs
        - unsquashfs: add code to only print "not superuser" error message once
        - unsquashfs: check for integer overflow in user input
        - mksquashfs: check for integer overflow in user input
        - mksquashfs: fix "new" variable leak in dir_scan1()
        - read_fs: prevent buffer {over|under}flow in read_block() with
          corrupted filesystems
        - read_fs: check metadata blocks are expected size in scan_inode_table()
        - read_fs: check the root inode block is found in scan_inode_table()
        - read_fs: Further harden scan_inode_table() against corrupted
          filesystems
        - unsquashfs: prevent buffer {over|under}flow in read_block() with
          corrupted filesystems
        - read_xattrs: harden xattr data reading against corrupted filesystems
        - unsquash-[23]: harden frag table reading against corrupted filesystems
        - unsquash-4.c: harden uid/gid & frag table reading against corruption
        - unsquashfs: harden inode/directory table reading against corruption
        - mksquashfs: improve out of space in output filesystem handling
        - mksquashfs: flag lseek error in writer as probable out of space
        - mksquashfs: flag lseek error in write_destination as probable out of
          space
        - mksquashfs: print file being squashed when ^\ (SIGQUIT) typed
        - mksquashfs: make EXIT_MKSQUASHFS() etc restore via new restore thread
        - mksquashfs: fix recursive restore failure check
        - info: dump queue and cache status if ^\ hit twice within one second
        - mksquashfs: fix rare race condition in "locked fragment" queueing
        - lz4: add experimental support for lz4 compression
        - lz4: add support for lz4 "high compression"
        - lzo_wrapper: new implementation with compression options
        - gzip_wrapper: add compression options
        - mksquashfs: redo -comp <compressor> parsing
        - mksquashfs: display compressor options when -X option isn't recognised
        - mksquashfs: add -Xhelp option
        - mksquashfs/unsquashfs: fix mtime signedness
        - Mksquashfs: optimise duplicate checking when appending
        - Mksquashfs: introduce additional per CPU fragment process threads
        - Mksquashfs: significantly optimise fragment duplicate checking
        - read_fs: scan_inode_table(), fix memory leak on filesystem corruption
        - pseudo: add_pseudo(), fix use of freed variable
        - mksquashfs/unsquashfs: exclude/extract/pseudo files, fix handling of
          leaf name
        - mksquashfs: rewrite default queue size so it's based on physical mem
        - mksquashfs: add a new -mem <mbytes> option
        - mksquashfs: fix limit on the number of dynamic pseudo files
        - mksquashfs: make -mem take a normal byte value, optionally with a
          K, M or G 

4.2     28 FEB 2011     XZ compression, and compression options support

        1. Filesystem improvements:

            1.1 Added XZ compression
            1.2 Added compression options support

        2. Miscellaneous improvements/bug fixes

            1.1 Add missing NO_XATTR filesystem flag to indicate no-xattrs
                option was specified and no xattrs should be stored when
                appending.
            1.2 Add suppport in Unquashfs -stat option for displaying
                NO_XATTR flag.
            1.3 Remove checkdata entry from Unsquashfs -stat option if a 4.0
                filesystem - checkdata is no longer supported.
            1.4 Fix appending bug when appending to an empty filesystem - this
                would be incorrectly treated as an error.
            1.5 Use glibc sys/xattr.h include rather than using attr/xattr.h
                which isn't present by default on some distributions.
            1.6 Unsquashfs, fix block calculation error with regular files when
                file size is between 2^32-block_size+1 and 2^32-1.
            1.7 Unsquashfs, fix sparse file writing when holes are larger than
                2^31-1.
            1.8 Add external CFLAGS and LDFLAGS support to Makefile, and allow
                build options to be specified on command line.  Also don't
                over-write passed in CFLAGS definition.
        

4.1     19 SEPT 2010    Major filesystem and tools improvements

        1. Filesystem improvements:

            1.1 Extended attribute support
            1.2 New compression framework
            1.3 Support for LZO compression
            1.4 Support for LZMA compression (not yet in mainline)

        2. Mksquashfs improvements:

            1.1 Enhanced pseudo file support
            1.2 New options for choosing compression algorithm used
            1.3 New options for controlling extended attributes
            1.4 Fix misalignment issues with memcpy etc. seen on ARM
            1.5 Fix floating point error in progress_bar when max == 0
            1.6 Removed use of get_nproc() call unavailable in ulibc
            1.7 Reorganised help text
          
        3. Unsquashfs improvements:

            1.1 New options for controlling extended attributes
            1.2 Fix misalignment issues with memcpy etc. seen on ARM
            1.3 Fix floating point error in progress_bar when max == 0
            1.4 Removed use of get_nproc() call unavailable in ulibc

          
4.0     5 APR 2009      Major filesystems improvements

        1. Kernel code improvements:

            1.1 Fixed little endian layout adopted.  All swapping macros
                removed, and in-line swapping added for big-endian
                architectures.
            1.2 Kernel code substantially improved and restructured.
            1.3 Kernel code split into separate files along functional lines.
            1.4 Vmalloc usage removed, and code changed to use separately
                allocated 4K buffers

        2. Unsquashfs improvements:

            2.1 Support for 4.0 filesystems added.
            2.2 Swapping macros rewritten.
            2.3 Unsquashfs code restructured and split into separate files.

        3. Mksquashfs improvements:

            3.1 Swapping macros rewritten.  Fixed little-endian layout allows
                code to be optimised and only added at compile time for
                big endian systems.
            3.2 Support for pseudo files added.
         
3.4     26 AUG 2008     Performance improvements to Unsquashfs, Mksquashfs
                        and the kernel code.  Plus many small bug fixes.

        1. Kernel code improvements:

            1.1 Internal Squashfs kernel metadata and fragment cache
                implementations have been merged and optimised.  Spinlocks are
                now used, locks are held for smaller periods and wakeups have
                been minimised.  Small race condition fixed where if two or
                more processes tried to read the same cache block
                simultaneously they would both read and decompress it.  10-20%+
                speed improvement has been seen on tests.
            1.2 NFS export code rewritten following VFS changes in
                linux-2.6.24.
            1.3 New patches for linux-2.6.25, linux-2.6.26, and linux-2.6.27.
                Fixed patch for linux-2.6.24.
            1.4 Fixed small buffer_head leak in squashfs_read_data when
                handling badly corrupted filesystems.
            1.5 Fixed bug in get_dir_index_using_offset.

        2. Unsquashfs improvements:

            2.1 Unsquashfs has been parallelised.  Filesystem reading, writing
                and decompression is now multi-threaded.  Up to 40% speed
                improvement seen on tests.
            2.2 Unsquashfs now has a progress bar.  Use -no-progress to
                disable it.
            2.3 Fixed small bug where unistd.h wasn't being included on
                some distributions, leading to lseek being used rather than
                lseek64 - which meant on these distributions Unsquashfs
                couldn't unsquash filesystems larger than 4GB.

       3. Mksquashfs improvements:

            3.1 Removed some small remaining parallelisation bottlenecks.
                Depending on source filesystem, up to 10%+ speed improvement.
            3.2 Progress bar improved, and moved to separate thread.
            3.3 Sparse file handling bug in Mksquashfs 3.3 fixed.
            3.4 Two rare appending restore bugs fixed (when ^C hit twice).


3.3     1 NOV 2007      Increase in block size, sparse file support,
                        Mksquashfs and Unsquashfs extended to use
                        pattern matching in exclude/extract files, plus
                        many more improvements and bug fixes.

        1. Filesystem improvements:

             1.1. Maximum block size has been increased to 1Mbyte, and the
                  default block size has been increased to 128 Kbytes.
                  This improves compression.

             1.2. Sparse files are now supported.  Sparse files are files
                  which have large areas of unallocated data commonly called
                  holes.  These files are now detected by Squashfs and stored
                  more efficiently.  This improves compression and read
                  performance for sparse files.

        2. Mksquashfs improvements:

           2.1.  Exclude files have been extended to use wildcard pattern
                 matching and regular expressions.  Support has also been
                 added for non-anchored excludes, which means it is
                 now possible to specify excludes which match anywhere
                 in the filesystem (i.e. leaf files), rather than always
                 having to specify exclude files starting from the root
                 directory (anchored excludes).

           2.2.  Recovery files are now created when appending to existing
                 Squashfs filesystems.  This allows the original filesystem
                 to be recovered if Mksquashfs aborts unexpectedly
                 (i.e. power failure).

        3. Unsquashfs improvements:

            3.1. Multiple extract files can now be specified on the
                 command line, and the files/directories to be extracted can
                 now also be given in a file.

            3.2. Extract files have been extended to use wildcard pattern
                 matching and regular expressions.

            3.3. Filename printing has been enhanced and Unquashfs can
                 now display filenames with file attributes
                 ('ls -l' style output).

            3.4. A -stat option has been added which displays the filesystem
                 superblock information.

            3.5. Unsquashfs now supports 1.x filesystems.

        4. Miscellaneous improvements/bug fixes:

            4.1. Squashfs kernel code improved to use SetPageError in
                 squashfs_readpage() if I/O error occurs.

            4.2. Fixed Squashfs kernel code bug preventing file
                 seeking beyond 2GB.

            4.3. Mksquashfs now detects file size changes between
                 first phase directory scan and second phase filesystem create.
                 It also deals better with file I/O errors.


3.2-r2  15 JAN 2007     Kernel patch update and progress bar bug fix

        1. Kernel patches 2.6.19/2.6.20 have been updated to use
           const structures and mutexes rather than older semaphores.
        2. Minor SMP bug fixes.
        3. Progress bar broken on x86-64.  Fixed.

3.2     2 JAN 2007      NFS support, improvements to the Squashfs-tools, major
                        bug fixes, lots of small improvements/bug fixes, and new
                        kernel patches.

        Improvements:

        1. Squashfs filesystems can now be exported via NFS.
        2. Unsquashfs now supports 2.x filesystems.
        3. Mksquashfs now displays a progress bar.
        4. Squashfs kernel code has been hardened against accidently or
           maliciously corrupted Squashfs filesystems.

        Bug fixes:

        5. Race condition occurring on S390 in readpage() fixed.
        6. Odd behaviour of MIPS memcpy in read_data() routine worked-around.
        7. Missing cache_flush in Squashfs symlink_readpage() added.
        

3.1-r2  30 AUG 2006     Mksquashfs -sort bug fix

                        A code optimisation after testing unfortunately
                        broke sorting in Mksquashfs.  This has been fixed.

3.1     19 AUG 2006     This release has some major improvements to
                        the squashfs-tools, a couple of major bug
                        fixes, lots of small improvements/bug fixes,
                        and new kernel patches.

                        
        1. Mksquashfs has been rewritten to be multi-threaded.  It
           has the following improvements

           1.1. Parallel compression.  By default as many compression and
                fragment compression threads are created as there are available
                processors.  This significantly speeds up performance on SMP
                systems.
           1.2. File input and filesystem output is peformed in parallel on
                separate threads to maximise I/O performance.  Even on single
                processor systems this speeds up performance by at least 10%.
           1.3. Appending has been significantly improved, and files within the
                filesystem being appended to are no longer scanned and
                checksummed.  This significantly improves append time for large
                filesystems.
           1.4. File duplicate checking has been optimised, and split into two
                separate phases.  Only files which are considered possible
                duplicates after the first phase are checksummed and cached in
                memory.
           1.5  The use of swap memory was found to significantly impact
                performance. The amount of memory used to cache files is now a
                command line option, by default this is 512 Mbytes.
 
        2. Unsquashfs has the following improvements

           2.1  Unsquashfs now allows you to specify the filename or the
                directory within the Squashfs filesystem that is to be
                extracted, rather than always extracting the entire filesystem.
           2.2  A new -force option has been added which forces Unsquashfs to
                output to the destination directory even if files and directories
                already exist in the destination directory.  This allows you to
                update an already existing directory tree, or to Unsquashfs to
                a partially filled directory tree.  Without the -force option
                Unsquashfs will refuse to output.

        3.  The following major bug fixes have been made

          3.1   A fragment table rounding bug has been fixed in Mksquashfs.
                Previously if the number of fragments in the filesystem
                were a multiple of 512, Mksquashfs would generate an
                incorrect filesystem.
          3.2   A rare SMP bug which occurred when simultaneously acccessing
                multiply mounted Squashfs filesystems has been fixed.

        4. Miscellaneous improvements/bug fixes

          4.1   Kernel code stack usage has been reduced.  This is to ensure
                Squashfs works with 4K stacks.
          4.2   Readdir (Squashfs kernel code) has been fixed to always
                return 0, rather than the number of directories read.  Squashfs
                should now interact better with NFS.
          4.3   Lseek bug in Mksquashfs when appending to larger than 4GB
                filesystems fixed.
          4.4   Squashfs 2.x initrds can now been mounted.
          4.5   Unsquashfs exit status fixed.
          4.6   New patches for linux-2.6.18 and linux-2.4.33.

        
3.0     15 MAR 2006     Major filesystem improvements

        1. Filesystems are no longer limited to 4 GB.  In
           theory 2^64 or 4 exabytes is now supported.
        2. Files are no longer limited to 4 GB.  In theory the maximum
           file size is 4 exabytes.
        3. Metadata (inode table and directory tables) are no longer
           restricted to 16 Mbytes.
        4. Hardlinks are now suppported.
        5. Nlink counts are now supported.
        6. Readdir now returns '.' and '..' entries.
        7. Special support for files larger than 256 MB has been added to
           the Squashfs kernel code for faster read access.
        8. Inode numbers are now stored within the inode rather than being
           computed from inode location on disk (this is not so much an
           improvement, but a change forced by the previously listed
           improvements).

2.2-r2  8 SEPT 2005     Second release of 2.2, this release fixes a couple
                        of small bugs, a couple of small documentation
                        mistakes, and adds a patch for kernel 2.6.13. 

        1. Mksquashfs now deletes the output filesystem image file if an
           error occurs whilst generating the filesystem.  Previously on
           error the image file was left empty or partially written.
        2. Updated mksquashfs so that it doesn't allow you to generate
           filesystems with block sizes smaller than 4K.  Squashfs hasn't
           supported block sizes less than 4K since 2.0-alpha.
        3. Mksquashfs now ignores missing files/directories in sort files.
           This was the original behaviour before 2.2.
        4. Fixed small mistake in fs/Kconfig where the version was still
           listed as 2.0.
        5. Updated ACKNOWLEDGEMENTS file.


2.2     3 JUL 2005      This release has some small improvements, bug fixes
                        and patches for new kernels.

        1. Sort routine re-worked and debugged from release 2.1.  It now allows
           you to give Mkisofs style sort files and checks for filenames that
           don't match anything.  Sort priority has also been changed to
           conform to Mkisofs usage, highest priority files are now placed
           at the start of the filesystem (this means they will be on the
           inside of a CD or DVD).
        2. New Configure options for embedded systems (memory constrained
           systems).  See INSTALL file for further details.
        3. Directory index bug fixed where chars were treated as signed on
           some architectures.  A file would not be found in the rare case
           that the filename started with a chracter greater than 127.
        4. Bug introduced into the read_data() routine when sped up to use data
           block queueing fixed.  If the second or later block resulted in an
           I/O error this was not checked.
        5. Append bug introduced in 2.1 fixed.  The code to compute the new
           compressed and uncompressed directory parts after appending was
           wrong.
        6. Metadata block length read routine altered to not perform a
           misaligned short read.  This was to fix reading on an ARM7 running
           uCLinux without a misaligned read interrupt handler.
        7. Checkdata bug introduced in 2.1 fixed.
        

2.1-r2  15 DEC 2004     Code changed so it can be compiled with gcc 2.x

        1.  In some of the code added for release 2.1 I unknowingly used some
            gcc extensions only supported by 3.x compilers.  I have received
            a couple of reports that the 2.1 release doesn't build on 2.x and so
            people are clearly still using gcc 2.x.  The code has been
            rewritten to remove these extensions.

2.1     10 DEC 2004     Significantly improved directory handling plus numerous
                        other smaller improvements

        1.  Fast indexed directories implemented.  These speed up directory
            operations (ls, file lookup etc.) significantly for directories
            larger than 8 KB.
        2.  All directories are now sorted in alphabetical order.  This again
            speeds up directory operations, and in some cases it also results in
            a small compression improvement (greater data similarity between
            files with alphabetically similar names).
        3.  Maximum directory size increased from 512 KB to 128 MB.
        4.  Duplicate fragment checking and appending optimised in mksquashfs,
            depending on filesystem, this is now up to 25% faster.
        5.  Mksquashfs help information reformatted and reorganised.
        6.  The Squashfs version and release date is now printed at kernel
            boot-time or module insertion.  This addition will hopefully help
            to reduce the growing problem where the Squashfs version supported
            by a kernel is unknown and the kernel source is unavailable.
        7.  New PERFORMANCE.README file.
        8.  New -2.0 mksquashfs option.
        9.  CHANGES file reorganised.
        10. README file reorganised, clarified and updated to include the 2.0
            mksquashfs options.
        11. New patch for Linux 2.6.9.
        12. New patch for Linux 2.4.28.

2.0r2   29 AUG 2004     Workaround for kernel bug in kernels 2.6.8 and newer
                        added

        1. New patch for kernel 2.6.8.1.  This includes a workaround for a
           kernel bug introduced in 2.6.7bk14, which is present in all later
           versions of the kernel.  

           If you're using a 2.6.8 kernel or later then you must use this
           2.6.8.1 patch.  If you've experienced hangs or oopses using Squashfs
           with a 2.6.8 or later kernel then you've hit this bug, and this
           patch will fix it.

           It is worth mentioning that this kernel bug potentially affects
           other filesystems.  If you receive odd results with other
           filesystems you may be experiencing this bug with that filesystem.
           I submitted a patch but this has not yet gone into the
           kernel, hopefully the bug will be fixed in later kernels. 

2.0     13 JULY 2004    A couple of new options, and some bug fixes

        1. New mksquashfs -all-root, -root-owned, -force-uid, and -force-gid
           options.  These allow the uids/gids of files in the generated
           filesystem to be specified, overriding the uids/gids in the
           source filesystem.
        2. Initrds are now supported for kernels 2.6.x.
        3. amd64 bug fixes.  If you use an amd64, please read the README-AMD64
           file.
        4. Check-data and gid bug fixes.  With 2.0-alpha when mounting 1.x
           filesystems in certain cases file gids were corrupted.
        5. New patch for Linux 2.6.7.

2.0-ALPHA       21 MAY 2004     Filesystem changes and compression improvements

        1. Squashfs 2.0 has added the concept of fragment blocks.
           Files smaller than the file block size and optionally the
           remainder of files that do not fit fully into a block (i.e. the
           last 32K in a 96K file) are packed into shared fragments and
           compressed together.  This achieves on average 5 - 20% better
           compression than Squashfs 1.x.
        2. The maximum block size has been increased to 64K (in the ALPHA
           version of Squashfs 2.0).
        3. The maximum number of UIDs has been increased to 256 (from 48 in
           1.x).
        4. The maximum number of GIDs has been increased to 256 (from 15 in
           1.x).
        5. Removal of sleep_on() function call in 2.6.x patch, to allow Squashfs
           to work on the Fedora rc2 kernel.
        6. Numerous small bug fixes have been made.

1.3r3   18 JAN 2004     Third release of 1.3, this adds a new mksquashfs option,
                        some bug fixes, and extra patches for new kernels

        1. New mksquashfs -ef exclude option.  This option reads the exclude
           dirs/files from an exclude file, one exclude dir/file per line.  This
           avoids the command line size limit when using the -e exclude option,
        2. When appending to existing filesystems, if mksquashfs experiences a
           fatal error (e.g. out of space when adding to the destination), the
           original filesystem is restored,
        3. Mksquashfs now builds standalone, without the kernel needing to be
           patched.
        4. Bug fix in the kernel squashfs filesystem, where the pages being
           filled were not kmapped.  This seems to only have caused problems
           on an Apple G5,
        5. New patch for Linux 2.4.24,

        6. New patch for Linux 2.6.1, this replaces the patch for 2.6.0-test7.

1.3r2   14 OCT 2003     Second release of 1.3, bug fixes and extra patches for
                        new kernels

        1. Bug fix in routine that adds files to the filesystem being
           generated in mksquashfs.  This bug was introduced in 1.3
           (not enough testing...) when I rewrote it to handle files larger
           than available memory.  This bug caused a SEGV, so if you've ever
           got that, it is now fixed,
        2. Long running bug where ls -s and du reported wrong block size
           fixed.  I'm pretty sure this used to work many kernel versions ago
           (2.4.7) but it broke somewhere along the line since then,
        3. New patch for Linux 2.4.22,
        4. New patch for 2.6.0-test7, this replaces the patch for 2.6.0-test1.

1.3     29 JUL 2003     FIFO/Socket support added plus optimisations and
                        improvements

        1. FIFOs and Socket inodes are now supported,
        2. Mksquashfs can now compress files larger than available
           memory,
        3. File duplicate check routine optimised,
        4. Exit codes fixed in Mksquashfs,
        5. Patch for Linux 2.4.21,
        6. Patch for Linux 2.6.0-test1.  Hopefully, this will work for
           the next few releases of 2.6.0-testx, otherwise, I'll be
           releasing a lot of updates to the 2.6.0 patch...

1.2     13 MAR 2003     Append feature and new mksquashfs options added

        Mksquashfs can now add to existing squashfs filesystems.  Three extra
        options "-noappend", "-keep-as-directory", and "root-becomes"
        have been added.

        The append option with file duplicate detection, means squashfs can be
        used as a simple versioning archiving filesystem. A squashfs
        filesystem can be created with for example the linux-2.4.19 source.
        Appending the linux-2.4.20 source will create a filesystem with the
        two source trees, but only the changed files will take extra room,
        the unchanged files will be detected as duplicates.

        See the README file for usage changes.

1.1b    16 JAN 2003     Bug fix release

        Fixed readpage deadlock bug.  This was a rare deadlock bug that
        happened when pushing pages into the page cache when using greater
        than 4K blocks.  I never got this bug when I tested the filesystem,
        but two people emailed me on the same day about the problem!
        I fixed it by using a page cache function that wasn't there when
        I originally did the work, which was nice :-)

1.1     8 JAN 2003      Added features

        1. Kernel squashfs can now mount different byte order filesystems.
        2. Additional features added to mksquashfs.  Mksquashfs now supports
           exclude files and multiple source files/directories can be
           specified.  A nopad option has also been added, which
           informs mksquashfs not to pad filesystems to a multiple of 4K.
           See README for mksquashfs usage changes.
        3. Greater than 2GB filesystems bug fix.  Filesystems greater than 2GB
           can now be created.

1.0c    14 NOV 2002     Bug fix release

        Fixed bugs with initrds and device nodes

1.0     23 OCT 2002     Initial release