diff options
Diffstat (limited to 'Documentation/filesystems/squashfs.txt')
| -rw-r--r-- | Documentation/filesystems/squashfs.txt | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt index d4d41465a0b..403c090aca3 100644 --- a/Documentation/filesystems/squashfs.txt +++ b/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 ----------------------------- @@ -91,8 +93,8 @@ byte alignment: Compressed data blocks are written to the filesystem as files are read from the source directory, and checked for duplicates. Once all file data has been -written the completed inode, directory, fragment, export and uid/gid lookup -tables are written. +written the completed inode, directory, fragment, export, uid/gid lookup and +xattr tables are written. 3.1 Compression options ----------------------- @@ -149,7 +151,7 @@ in each metadata block. Directories are sorted in alphabetical order, and at lookup the index is scanned linearly looking for the first filename alphabetically larger than the filename being looked up. At this point the location of the metadata block the filename is in has been found. -The general idea of the index is ensure only one metadata block needs to be +The general idea of the index is to ensure only one metadata block needs to be decompressed to do a lookup irrespective of the length of the directory. This scheme has the advantage that it doesn't require extra memory overhead and doesn't require much extra storage on disk. |