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Linux kernel mirror (for testing)
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linux
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 which will be used as the default ID for that mount.
40They will also accept the string "ignore" and "forget". For files on the disk
41that are owned by nobody ( -1 ), they will instead look as if they are owned
42by the default ID. The ignore option causes the default ID to override all
43IDs on the disk, not just -1. The forget option causes all IDs to be written
44to disk as -1, so when the media is later remounted, they will appear to be
45owned by whatever default ID it is mounted with at that time.
46
47For typical desktop use of removable media, you should set the ID to that
48of the interactively logged on user, and also specify both the forget and
49ignore options. This way the interactive user will always see the files
50on the disk as belonging to him.
51
52The remaining are for debugging and disaster recovery:
53
54 novrs Skip volume sequence recognition
55
56The following expect a offset from 0.
57
58 session= Set the CDROM session (default= last session)
59 anchor= Override standard anchor location. (default= 256)
60 volume= Override the VolumeDesc location. (unused)
61 partition= Override the PartitionDesc location. (unused)
62 lastblock= Set the last block of the filesystem/
63
64The following expect a offset from the partition root.
65
66 fileset= Override the fileset block location. (unused)
67 rootdir= Override the root directory location. (unused)
68 WARNING: overriding the rootdir to a non-directory may
69 yield highly unpredictable results.
70-------------------------------------------------------------------------------
71
72
73For the latest version and toolset see:
74 https://github.com/pali/udftools
75
76Documentation on UDF and ECMA 167 is available FREE from:
77 http://www.osta.org/
78 http://www.ecma-international.org/