docs: filesystems: convert squashfs.txt to ReST (31771f45) · Commits · 戴 / test

Documentation/filesystems/index.rst

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		@@ -86,5 +86,6 @@ Documentation for filesystem implementations.
		ramfs-rootfs-initramfs
		relay
		romfs
		squashfs
		virtiofs
		vfat

Documentation/filesystems/squashfs.txt→Documentation/filesystems/squashfs.rst

+33 −27

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		SQUASHFS 4.0 FILESYSTEM
		.. SPDX-License-Identifier: GPL-2.0

		=======================
		Squashfs 4.0 Filesystem
		=======================

		Squashfs is a compressed read-only filesystem for Linux.

		It uses zlib, lz4, lzo, or 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
		@@ -15,31 +19,33 @@ needed.
		Mailing list: squashfs-devel@lists.sourceforge.net
		Web site: www.squashfs.org

		1. FILESYSTEM FEATURES
		1. Filesystem Features
		----------------------

		Squashfs filesystem features versus Cramfs:

		============================== ========= ==========
		Squashfs Cramfs

		Max filesystem size: 2^64 256 MiB
		Max file size: ~ 2 TiB 16 MiB
		Max files: unlimited unlimited
		Max directories: unlimited unlimited
		Max entries per directory: unlimited unlimited
		Max block size: 1 MiB 4 KiB
		Metadata compression: yes no
		Directory indexes: yes no
		Sparse file support: yes no
		Tail-end packing (fragments): yes no
		Exportable (NFS etc.): yes no
		Hard link support: yes no
		"." and ".." in readdir: yes no
		Real inode numbers: yes no
		32-bit uids/gids: yes no
		File creation time: yes no
		Xattr support: yes no
		ACL support: no no
		============================== ========= ==========
		Max filesystem size 2^64 256 MiB
		Max file size ~ 2 TiB 16 MiB
		Max files unlimited unlimited
		Max directories unlimited unlimited
		Max entries per directory unlimited unlimited
		Max block size 1 MiB 4 KiB
		Metadata compression yes no
		Directory indexes yes no
		Sparse file support yes no
		Tail-end packing (fragments) yes no
		Exportable (NFS etc.) yes no
		Hard link support yes no
		"." and ".." in readdir yes no
		Real inode numbers yes no
		32-bit uids/gids yes no
		File creation time yes no
		Xattr support yes no
		ACL support no no
		============================== ========= ==========

		Squashfs compresses data, inodes and directories. In addition, inode and
		directory data are highly compacted, and packed on byte boundaries. Each
		@@ -47,7 +53,7 @@ compressed inode is on average 8 bytes in length (the exact length varies on
		file type, i.e. regular file, directory, symbolic link, and block/char device
		inodes have different sizes).

		2. USING SQUASHFS
		2. Using Squashfs
		-----------------

		As squashfs is a read-only filesystem, the mksquashfs program must be used to
		@@ -58,11 +64,11 @@ 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
		3. Squashfs Filesystem Design
		-----------------------------

		A squashfs filesystem consists of a maximum of nine parts, packed together on a
		byte alignment:
		byte alignment::

		---------------
		\| superblock \|
		@@ -229,15 +235,15 @@ location of the xattr list inside each inode, a 32-bit xattr id
		is stored. This xattr id is mapped into the location of the xattr
		list using a second xattr id lookup table.

		4. TODOS AND OUTSTANDING ISSUES
		4. TODOs and Outstanding Issues
		-------------------------------

		4.1 Todo list
		4.1 TODO list
		-------------

		Implement ACL support.

		4.2 Squashfs internal cache
		4.2 Squashfs Internal Cache
		---------------------------

		Blocks in Squashfs are compressed. To avoid repeatedly decompressing

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