udf.rst 3.0 KB

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  1. .. SPDX-License-Identifier: GPL-2.0
  2. ===============
  3. UDF file system
  4. ===============
  5. If you encounter problems with reading UDF discs using this driver,
  6. please report them according to MAINTAINERS file.
  7. Write support requires a block driver which supports writing. Currently
  8. dvd+rw drives and media support true random sector writes, and so a udf
  9. filesystem on such devices can be directly mounted read/write. CD-RW
  10. media however, does not support this. Instead the media can be formatted
  11. for packet mode using the utility cdrwtool, then the pktcdvd driver can
  12. be bound to the underlying cd device to provide the required buffering
  13. and read-modify-write cycles to allow the filesystem random sector writes
  14. while providing the hardware with only full packet writes. While not
  15. required for dvd+rw media, use of the pktcdvd driver often enhances
  16. performance due to very poor read-modify-write support supplied internally
  17. by drive firmware.
  18. -------------------------------------------------------------------------------
  19. The following mount options are supported:
  20. =========== ======================================
  21. gid= Set the default group.
  22. umask= Set the default umask.
  23. mode= Set the default file permissions.
  24. dmode= Set the default directory permissions.
  25. uid= Set the default user.
  26. bs= Set the block size.
  27. unhide Show otherwise hidden files.
  28. undelete Show deleted files in lists.
  29. adinicb Embed data in the inode (default)
  30. noadinicb Don't embed data in the inode
  31. shortad Use short ad's
  32. longad Use long ad's (default)
  33. nostrict Unset strict conformance
  34. iocharset= Set the NLS character set
  35. =========== ======================================
  36. The uid= and gid= options need a bit more explaining. They will accept a
  37. decimal numeric value and all inodes on that mount will then appear as
  38. belonging to that uid and gid. Mount options also accept the string "forget".
  39. The forget option causes all IDs to be written to disk as -1 which is a way
  40. of UDF standard to indicate that IDs are not supported for these files .
  41. For typical desktop use of removable media, you should set the ID to that of
  42. the interactively logged on user, and also specify the forget option. This way
  43. the interactive user will always see the files on the disk as belonging to him.
  44. The remaining are for debugging and disaster recovery:
  45. ===== ================================
  46. novrs Skip volume sequence recognition
  47. ===== ================================
  48. The following expect a offset from 0.
  49. ========== =================================================
  50. session= Set the CDROM session (default= last session)
  51. anchor= Override standard anchor location. (default= 256)
  52. lastblock= Set the last block of the filesystem/
  53. ========== =================================================
  54. -------------------------------------------------------------------------------
  55. For the latest version and toolset see:
  56. https://github.com/pali/udftools
  57. Documentation on UDF and ECMA 167 is available FREE from:
  58. - http://www.osta.org/
  59. - https://www.ecma-international.org/