config SQUASHFS
  	tristate "SquashFS 4.0 - Squashed file system support"
  	depends on BLOCK
  	help
  	  Saying Y here includes support for SquashFS 4.0 (a Compressed
  	  Read-Only File System).  Squashfs is a highly compressed read-only
  	  filesystem for Linux.  It uses zlib, lzo or xz compression to
  	  compress both files, inodes and directories.  Inodes in the system
  	  are very small and all blocks are packed to minimise data overhead.
  	  Block sizes greater than 4K are supported up to a maximum of 1 Mbytes
  	  (default block size 128K).  SquashFS 4.0 supports 64 bit filesystems
  	  and files (larger than 4GB), full uid/gid information, hard links and
  	  timestamps.
  
  	  Squashfs is intended for general read-only filesystem use, for
  	  archival use (i.e. in cases where a .tar.gz file may be used), and in
  	  embedded systems where low overhead is needed.  Further information
  	  and tools are available from http://squashfs.sourceforge.net.
  
  	  If you want to compile this as a module ( = code which can be
  	  inserted in and removed from the running kernel whenever you want),
  	  say M here.  The module will be called squashfs.  Note that the root
  	  file system (the one containing the directory /) cannot be compiled
  	  as a module.
  
  	  If unsure, say N.
  
  choice
  	prompt "Decompressor parallelisation options"
  	depends on SQUASHFS
  	help
  	  Squashfs now supports three parallelisation options for
  	  decompression.  Each one exhibits various trade-offs between
  	  decompression performance and CPU and memory usage.
  
  	  If in doubt, select "Single threaded compression"
  
  config SQUASHFS_DECOMP_SINGLE
  	bool "Single threaded compression"
  	help
  	  Traditionally Squashfs has used single-threaded decompression.
  	  Only one block (data or metadata) can be decompressed at any
  	  one time.  This limits CPU and memory usage to a minimum.
  
  config SQUASHFS_DECOMP_MULTI
  	bool "Use multiple decompressors for parallel I/O"
  	help
  	  By default Squashfs uses a single decompressor but it gives
  	  poor performance on parallel I/O workloads when using multiple CPU
  	  machines due to waiting on decompressor availability.
  
  	  If you have a parallel I/O workload and your system has enough memory,
  	  using this option may improve overall I/O performance.
  
  	  This decompressor implementation uses up to two parallel
  	  decompressors per core.  It dynamically allocates decompressors
  	  on a demand basis.
  
  config SQUASHFS_DECOMP_MULTI_PERCPU
  	bool "Use percpu multiple decompressors for parallel I/O"
  	help
  	  By default Squashfs uses a single decompressor but it gives
  	  poor performance on parallel I/O workloads when using multiple CPU
  	  machines due to waiting on decompressor availability.
  
  	  This decompressor implementation uses a maximum of one
  	  decompressor per core.  It uses percpu variables to ensure
  	  decompression is load-balanced across the cores.
  
  endchoice
  
  config SQUASHFS_XATTR
  	bool "Squashfs XATTR support"
  	depends on SQUASHFS
  	help
  	  Saying Y here includes support for extended attributes (xattrs).
  	  Xattrs are name:value pairs associated with inodes by
  	  the kernel or by users (see the attr(5) manual page).
  
  	  If unsure, say N.
  
  config SQUASHFS_ZLIB
  	bool "Include support for ZLIB compressed file systems"
  	depends on SQUASHFS
  	select ZLIB_INFLATE
  	default y
  	help
  	  ZLIB compression is the standard compression used by Squashfs
  	  file systems.  It offers a good trade-off between compression
  	  achieved and the amount of CPU time and memory necessary to
  	  compress and decompress.
  
  	  If unsure, say Y.
  
  config SQUASHFS_LZ4
  	bool "Include support for LZ4 compressed file systems"
  	depends on SQUASHFS
  	select LZ4_DECOMPRESS
  	help
  	  Saying Y here includes support for reading Squashfs file systems
  	  compressed with LZ4 compression.  LZ4 compression is mainly
  	  aimed at embedded systems with slower CPUs where the overheads
  	  of zlib are too high.
  
  	  LZ4 is not the standard compression used in Squashfs and so most
  	  file systems will be readable without selecting this option.
  
  	  If unsure, say N.
  
  config SQUASHFS_LZO
  	bool "Include support for LZO compressed file systems"
  	depends on SQUASHFS
  	select LZO_DECOMPRESS
  	help
  	  Saying Y here includes support for reading Squashfs file systems
  	  compressed with LZO compression.  LZO compression is mainly
  	  aimed at embedded systems with slower CPUs where the overheads
  	  of zlib are too high.
  
  	  LZO is not the standard compression used in Squashfs and so most
  	  file systems will be readable without selecting this option.
  
  	  If unsure, say N.
  
  config SQUASHFS_XZ
  	bool "Include support for XZ compressed file systems"
  	depends on SQUASHFS
  	select XZ_DEC
  	help
  	  Saying Y here includes support for reading Squashfs file systems
  	  compressed with XZ compression.  XZ gives better compression than
  	  the default zlib compression, at the expense of greater CPU and
  	  memory overhead.
  
  	  XZ is not the standard compression used in Squashfs and so most
  	  file systems will be readable without selecting this option.
  
  	  If unsure, say N.
  
  config SQUASHFS_ZSTD
  	bool "Include support for ZSTD compressed file systems"
  	depends on SQUASHFS
  	select ZSTD_DECOMPRESS
  	help
  	  Saying Y here includes support for reading Squashfs file systems
  	  compressed with ZSTD compression.  ZSTD gives better compression than
  	  the default ZLIB compression, while using less CPU.
  
  	  ZSTD is not the standard compression used in Squashfs and so most
  	  file systems will be readable without selecting this option.
  
  	  If unsure, say N.
  
  config SQUASHFS_4K_DEVBLK_SIZE
  	bool "Use 4K device block size?"
  	depends on SQUASHFS
  	help
  	  By default Squashfs sets the dev block size (sb_min_blocksize)
  	  to 1K or the smallest block size supported by the block device
  	  (if larger).  This, because blocks are packed together and
  	  unaligned in Squashfs, should reduce latency.
  
  	  This, however, gives poor performance on MTD NAND devices where
  	  the optimal I/O size is 4K (even though the devices can support
  	  smaller block sizes).
  
  	  Using a 4K device block size may also improve overall I/O
  	  performance for some file access patterns (e.g. sequential
  	  accesses of files in filesystem order) on all media.
  
  	  Setting this option will force Squashfs to use a 4K device block
  	  size by default.
  
  	  If unsure, say N.
  
  config SQUASHFS_EMBEDDED
  	bool "Additional option for memory-constrained systems"
  	depends on SQUASHFS
  	help
  	  Saying Y here allows you to specify cache size.
  
  	  If unsure, say N.
  
  config SQUASHFS_FRAGMENT_CACHE_SIZE
  	int "Number of fragments cached" if SQUASHFS_EMBEDDED
  	depends on SQUASHFS
  	default "3"
  	help
  	  By default SquashFS caches the last 3 fragments read from
  	  the filesystem.  Increasing this amount may mean SquashFS
  	  has to re-read fragments less often from disk, at the expense
  	  of extra system memory.  Decreasing this amount will mean
  	  SquashFS uses less memory at the expense of extra reads from disk.
  
  	  Note there must be at least one cached fragment.  Anything
  	  much more than three will probably not make much difference.