[linux-2.6-block.git] / Documentation / filesystems / udf.txt

*
* Documentation/filesystems/udf.txt
*

If you encounter problems with reading UDF discs using this driver,
please report them according to MAINTAINERS file.

Write support requires a block driver which supports writing.  Currently
dvd+rw drives and media support true random sector writes, and so a udf
filesystem on such devices can be directly mounted read/write.  CD-RW
media however, does not support this.  Instead the media can be formatted
for packet mode using the utility cdrwtool, then the pktcdvd driver can
be bound to the underlying cd device to provide the required buffering
and read-modify-write cycles to allow the filesystem random sector writes
while providing the hardware with only full packet writes.  While not
required for dvd+rw media, use of the pktcdvd driver often enhances
performance due to very poor read-modify-write support supplied internally
by drive firmware.

-------------------------------------------------------------------------------
The following mount options are supported:

	gid=		Set the default group.
	umask=		Set the default umask.
	mode=		Set the default file permissions.
	dmode=		Set the default directory permissions.
	uid=		Set the default user.
	bs=		Set the block size.
	unhide		Show otherwise hidden files.
	undelete	Show deleted files in lists.
	adinicb		Embed data in the inode (default)
	noadinicb	Don't embed data in the inode
	shortad		Use short ad's
	longad		Use long ad's (default)
	nostrict	Unset strict conformance
	iocharset=	Set the NLS character set

The uid= and gid= options need a bit more explaining.  They will accept a
decimal numeric value and all inodes on that mount will then appear as
belonging to that uid and gid.  Mount options also accept the string "forget".
The forget option causes all IDs to be written to disk as -1 which is a way
of UDF standard to indicate that IDs are not supported for these files .

For typical desktop use of removable media, you should set the ID to that of
the interactively logged on user, and also specify the forget option.  This way
the interactive user will always see the files on the disk as belonging to him.

The remaining are for debugging and disaster recovery:

	novrs		Skip volume sequence recognition 

The following expect a offset from 0.

	session=	Set the CDROM session (default= last session)
	anchor=		Override standard anchor location. (default= 256)
	lastblock=	Set the last block of the filesystem/

-------------------------------------------------------------------------------


For the latest version and toolset see:
	https://github.com/pali/udftools

Documentation on UDF and ECMA 167 is available FREE from:
	http://www.osta.org/
	http://www.ecma-international.org/
Commit	Line	Data
1da177e4 LT	1	*
	2	* Documentation/filesystems/udf.txt
	3	*
1da177e4 LT	4
1da177e4 LT	5	If you encounter problems with reading UDF discs using this driver,
503c3117	6	please report them according to MAINTAINERS file.
1da177e4	7
55aa601e PS	8	Write support requires a block driver which supports writing. Currently
	9	dvd+rw drives and media support true random sector writes, and so a udf
	10	filesystem on such devices can be directly mounted read/write. CD-RW
	11	media however, does not support this. Instead the media can be formatted
	12	for packet mode using the utility cdrwtool, then the pktcdvd driver can
	13	be bound to the underlying cd device to provide the required buffering
	14	and read-modify-write cycles to allow the filesystem random sector writes
	15	while providing the hardware with only full packet writes. While not
	16	required for dvd+rw media, use of the pktcdvd driver often enhances
	17	performance due to very poor read-modify-write support supplied internally
	18	by drive firmware.
1da177e4 LT	19
	20	-------------------------------------------------------------------------------
	21	The following mount options are supported:
	22
	23	gid= Set the default group.
	24	umask= Set the default umask.
7ac9bcd5 MS	25	mode= Set the default file permissions.
7ac9bcd5 MS	26	dmode= Set the default directory permissions.
1da177e4 LT	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
0e6b3e5e	38	The uid= and gid= options need a bit more explaining. They will accept a
6ccd5194 JK	39	decimal numeric value and all inodes on that mount will then appear as
	40	belonging to that uid and gid. Mount options also accept the string "forget".
	41	The forget option causes all IDs to be written to disk as -1 which is a way
	42	of UDF standard to indicate that IDs are not supported for these files .
0e6b3e5e	43
6ccd5194 JK	44	For typical desktop use of removable media, you should set the ID to that of
	45	the interactively logged on user, and also specify the forget option. This way
	46	the interactive user will always see the files on the disk as belonging to him.
0e6b3e5e	47
1da177e4 LT	48	The remaining are for debugging and disaster recovery:
	49
	50	novrs Skip volume sequence recognition
	51
	52	The following expect a offset from 0.
	53
	54	session= Set the CDROM session (default= last session)
	55	anchor= Override standard anchor location. (default= 256)
1da177e4 LT	56	lastblock= Set the last block of the filesystem/
1da177e4 LT	57
1da177e4 LT	58	-------------------------------------------------------------------------------
	59
	60
	61	For the latest version and toolset see:
503c3117	62	https://github.com/pali/udftools
1da177e4 LT	63
	64	Documentation on UDF and ECMA 167 is available FREE from:
	65	http://www.osta.org/
	66	http://www.ecma-international.org/