0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 ===============
0004 UDF file system
0005 ===============
0006
0007 If you encounter problems with reading UDF discs using this driver,
0008 please report them according to MAINTAINERS file.
0009
0010 Write support requires a block driver which supports writing. Currently
0011 dvd+rw drives and media support true random sector writes, and so a udf
0012 filesystem on such devices can be directly mounted read/write. CD-RW
0013 media however, does not support this. Instead the media can be formatted
0014 for packet mode using the utility cdrwtool, then the pktcdvd driver can
0015 be bound to the underlying cd device to provide the required buffering
0016 and read-modify-write cycles to allow the filesystem random sector writes
0017 while providing the hardware with only full packet writes. While not
0018 required for dvd+rw media, use of the pktcdvd driver often enhances
0019 performance due to very poor read-modify-write support supplied internally
0020 by drive firmware.
0021
0022 -------------------------------------------------------------------------------
0023
0024 The following mount options are supported:
0025
0026 =========== ======================================
0027 gid= Set the default group.
0028 umask= Set the default umask.
0029 mode= Set the default file permissions.
0030 dmode= Set the default directory permissions.
0031 uid= Set the default user.
0032 bs= Set the block size.
0033 unhide Show otherwise hidden files.
0034 undelete Show deleted files in lists.
0035 adinicb Embed data in the inode (default)
0036 noadinicb Don't embed data in the inode
0037 shortad Use short ad's
0038 longad Use long ad's (default)
0039 nostrict Unset strict conformance
0040 iocharset= Set the NLS character set
0041 =========== ======================================
0042
0043 The uid= and gid= options need a bit more explaining. They will accept a
0044 decimal numeric value and all inodes on that mount will then appear as
0045 belonging to that uid and gid. Mount options also accept the string "forget".
0046 The forget option causes all IDs to be written to disk as -1 which is a way
0047 of UDF standard to indicate that IDs are not supported for these files .
0048
0049 For typical desktop use of removable media, you should set the ID to that of
0050 the interactively logged on user, and also specify the forget option. This way
0051 the interactive user will always see the files on the disk as belonging to him.
0052
0053 The remaining are for debugging and disaster recovery:
0054
0055 ===== ================================
0056 novrs Skip volume sequence recognition
0057 ===== ================================
0058
0059 The following expect a offset from 0.
0060
0061 ========== =================================================
0062 session= Set the CDROM session (default= last session)
0063 anchor= Override standard anchor location. (default= 256)
0064 lastblock= Set the last block of the filesystem/
0065 ========== =================================================
0066
0067 -------------------------------------------------------------------------------
0068
0069
0070 For the latest version and toolset see:
0071 https://github.com/pali/udftools
0072
0073 Documentation on UDF and ECMA 167 is available FREE from:
0074 - http://www.osta.org/
0075 - https://www.ecma-international.org/
