summaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems/ecryptfs.rst
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /Documentation/filesystems/ecryptfs.rst
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'Documentation/filesystems/ecryptfs.rst')
-rw-r--r--Documentation/filesystems/ecryptfs.rst86
1 files changed, 86 insertions, 0 deletions
diff --git a/Documentation/filesystems/ecryptfs.rst b/Documentation/filesystems/ecryptfs.rst
new file mode 100644
index 000000000..1f2edef4c
--- /dev/null
+++ b/Documentation/filesystems/ecryptfs.rst
@@ -0,0 +1,86 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================================================
+eCryptfs: A stacked cryptographic filesystem for Linux
+======================================================
+
+eCryptfs is free software. Please see the file COPYING for details.
+For documentation, please see the files in the doc/ subdirectory. For
+building and installation instructions please see the INSTALL file.
+
+:Maintainer: Phillip Hellewell
+:Lead developer: Michael A. Halcrow <mhalcrow@us.ibm.com>
+:Developers: Michael C. Thompson
+ Kent Yoder
+:Web Site: http://ecryptfs.sf.net
+
+This software is currently undergoing development. Make sure to
+maintain a backup copy of any data you write into eCryptfs.
+
+eCryptfs requires the userspace tools downloadable from the
+SourceForge site:
+
+http://sourceforge.net/projects/ecryptfs/
+
+Userspace requirements include:
+
+- David Howells' userspace keyring headers and libraries (version
+ 1.0 or higher), obtainable from
+ http://people.redhat.com/~dhowells/keyutils/
+- Libgcrypt
+
+
+.. note::
+
+ In the beta/experimental releases of eCryptfs, when you upgrade
+ eCryptfs, you should copy the files to an unencrypted location and
+ then copy the files back into the new eCryptfs mount to migrate the
+ files.
+
+
+Mount-wide Passphrase
+=====================
+
+Create a new directory into which eCryptfs will write its encrypted
+files (i.e., /root/crypt). Then, create the mount point directory
+(i.e., /mnt/crypt). Now it's time to mount eCryptfs::
+
+ mount -t ecryptfs /root/crypt /mnt/crypt
+
+You should be prompted for a passphrase and a salt (the salt may be
+blank).
+
+Try writing a new file::
+
+ echo "Hello, World" > /mnt/crypt/hello.txt
+
+The operation will complete. Notice that there is a new file in
+/root/crypt that is at least 12288 bytes in size (depending on your
+host page size). This is the encrypted underlying file for what you
+just wrote. To test reading, from start to finish, you need to clear
+the user session keyring:
+
+keyctl clear @u
+
+Then umount /mnt/crypt and mount again per the instructions given
+above.
+
+::
+
+ cat /mnt/crypt/hello.txt
+
+
+Notes
+=====
+
+eCryptfs version 0.1 should only be mounted on (1) empty directories
+or (2) directories containing files only created by eCryptfs. If you
+mount a directory that has pre-existing files not created by eCryptfs,
+then behavior is undefined. Do not run eCryptfs in higher verbosity
+levels unless you are doing so for the sole purpose of debugging or
+development, since secret values will be written out to the system log
+in that case.
+
+
+Mike Halcrow
+mhalcrow@us.ibm.com