Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: Make ZLIB compression support optional
  Squashfs: Update documentation for XZ and add squashfs-tools devel tree

Author: torvalds

Documentation/filesystems/squashfs.txt

@@ -2,7 +2,7 @@ SQUASHFS 4.0 FILESYSTEM
 =======================
 
 Squashfs is a compressed read-only filesystem for Linux.
-It uses zlib/lzo compression to compress files, inodes and directories.
+It uses zlib/lzo/xz compression to compress 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 1Mbytes (default block size 128K).
@@ -55,6 +55,8 @@ create populated squashfs filesystems.  This and other squashfs utilities
 can be obtained from http://www.squashfs.org.  Usage instructions can be
 obtained from this site also.
 
+The squashfs-tools development tree is now located on kernel.org
+	git://git.kernel.org/pub/scm/fs/squashfs/squashfs-tools.git
 
 3. SQUASHFS FILESYSTEM DESIGN
 -----------------------------

fs/squashfs/Kconfig

@@ -1,7 +1,6 @@
 config SQUASHFS
 	tristate "SquashFS 4.0 - Squashed file system support"
 	depends on BLOCK
-	select ZLIB_INFLATE
 	help
 	  Saying Y here includes support for SquashFS 4.0 (a Compressed
 	  Read-Only File System).  Squashfs is a highly compressed read-only
@@ -36,6 +35,19 @@ config SQUASHFS_XATTR
 
 	  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_LZO
 	bool "Include support for LZO compressed file systems"
 	depends on SQUASHFS

fs/squashfs/Makefile

@@ -4,7 +4,8 @@
 
 obj-$(CONFIG_SQUASHFS) += squashfs.o
 squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
-squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
+squashfs-y += namei.o super.o symlink.o decompressor.o
 squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
 squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
 squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
+squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o

fs/squashfs/decompressor.c

@@ -52,6 +52,12 @@ static const struct squashfs_decompressor squashfs_xz_comp_ops = {
 };
 #endif
 
+#ifndef CONFIG_SQUASHFS_ZLIB
+static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
+	NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
+};
+#endif
+
 static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
 	NULL, NULL, NULL, 0, "unknown", 0
 };

fs/squashfs/decompressor.h

@@ -56,4 +56,8 @@ extern const struct squashfs_decompressor squashfs_xz_comp_ops;
 extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
 #endif
 
+#ifdef CONFIG_SQUASHFS_ZLIB
+extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
+#endif
+
 #endif

fs/squashfs/squashfs.h

@@ -97,6 +97,3 @@ extern const struct inode_operations squashfs_symlink_inode_ops;
 
 /* xattr.c */
 extern const struct xattr_handler *squashfs_xattr_handlers[];
-
-/* zlib_wrapper.c */
-extern const struct squashfs_decompressor squashfs_zlib_comp_ops;