1*
2* Documentation/filesystems/udf.txt
3*
4
5If you encounter problems with reading UDF discs using this driver,
6please report them according to MAINTAINERS file.
7
8Write support requires a block driver which supports writing.  Currently
9dvd+rw drives and media support true random sector writes, and so a udf
10filesystem on such devices can be directly mounted read/write.  CD-RW
11media however, does not support this.  Instead the media can be formatted
12for packet mode using the utility cdrwtool, then the pktcdvd driver can
13be bound to the underlying cd device to provide the required buffering
14and read-modify-write cycles to allow the filesystem random sector writes
15while providing the hardware with only full packet writes.  While not
16required for dvd+rw media, use of the pktcdvd driver often enhances
17performance due to very poor read-modify-write support supplied internally
18by drive firmware.
19
20-------------------------------------------------------------------------------
21The following mount options are supported:
22
23	gid=		Set the default group.
24	umask=		Set the default umask.
25	mode=		Set the default file permissions.
26	dmode=		Set the default directory permissions.
27	uid=		Set the default user.
28	bs=		Set the block size.
29	unhide		Show otherwise hidden files.
30	undelete	Show deleted files in lists.
31	adinicb		Embed data in the inode (default)
32	noadinicb	Don't embed data in the inode
33	shortad		Use short ad's
34	longad		Use long ad's (default)
35	nostrict	Unset strict conformance
36	iocharset=	Set the NLS character set
37
38The uid= and gid= options need a bit more explaining.  They will accept a
39decimal numeric value and all inodes on that mount will then appear as
40belonging to that uid and gid.  Mount options also accept the string "forget".
41The forget option causes all IDs to be written to disk as -1 which is a way
42of UDF standard to indicate that IDs are not supported for these files .
43
44For typical desktop use of removable media, you should set the ID to that of
45the interactively logged on user, and also specify the forget option.  This way
46the interactive user will always see the files on the disk as belonging to him.
47
48The remaining are for debugging and disaster recovery:
49
50	novrs		Skip volume sequence recognition
51
52The following expect a offset from 0.
53
54	session=	Set the CDROM session (default= last session)
55	anchor=		Override standard anchor location. (default= 256)
56	lastblock=	Set the last block of the filesystem/
57
58-------------------------------------------------------------------------------
59
60
61For the latest version and toolset see:
62	https://github.com/pali/udftools
63
64Documentation on UDF and ECMA 167 is available FREE from:
65	http://www.osta.org/
66	http://www.ecma-international.org/
67