summaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems/udf.rst
diff options
context:
space:
mode:
authorHaojie Li <lihaojie@kylinos.cn>2026-08-25 18:08:45 +0800
committerChun-Kuang Hu <chunkuang.hu@kernel.org>2026-09-28 23:20:55 +0000
commitbce7698e2e6565bb765bd0522337f29f5f312624 (patch)
tree0b735b7b4a27369cb4d75d9431b3ee59ce7e5bcc /Documentation/filesystems/udf.rst
downloadlinux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.tar.gz
linux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.zip
drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted
platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li <lihaojie@kylinos.cn> Reviewed-by: CK Hu <ck.hu@mediatek.com> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Diffstat (limited to 'Documentation/filesystems/udf.rst')
-rw-r--r--Documentation/filesystems/udf.rst75
1 files changed, 75 insertions, 0 deletions
diff --git a/Documentation/filesystems/udf.rst b/Documentation/filesystems/udf.rst
new file mode 100644
index 000000000..f9489ddbb
--- /dev/null
+++ b/Documentation/filesystems/udf.rst
@@ -0,0 +1,75 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+UDF file system
+===============
+
+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/
+ - https://www.ecma-international.org/