Merge android-4.14.109 (80571db) into msm-4.14 (313f4c9c) · Commits · e / devices / android_kernel_oneplus_sm8150

Documentation/ABI/testing/sysfs-fs-f2fs

+7 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,13 @@ Description:
		The unit size is one block, now only support configuring in range
		of [1, 512].

		What: /sys/fs/f2fs/<disk>/umount_discard_timeout
		Date: January 2019
		Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
		Description:
		Set timeout to issue discard commands during umount.
		Default: 5 secs

		What: /sys/fs/f2fs/<disk>/max_victim_search
		Date: January 2014
		Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>

Documentation/device-mapper/dm-bow.txt

0 → 100644

+99 −0

Original line number	Diff line number	Diff line
		dm_bow (backup on write)
		========================

		dm_bow is a device mapper driver that uses the free space on a device to back up
		data that is overwritten. The changes can then be committed by a simple state
		change, or rolled back by removing the dm_bow device and running a command line
		utility over the underlying device.

		dm_bow has three states, set by writing ‘1’ or ‘2’ to /sys/block/dm-?/bow/state.
		It is only possible to go from state 0 (initial state) to state 1, and then from
		state 1 to state 2.

		State 0: dm_bow collects all trims to the device and assumes that these mark
		free space on the overlying file system that can be safely used. Typically the
		mount code would create the dm_bow device, mount the file system, call the
		FITRIM ioctl on the file system then switch to state 1. These trims are not
		propagated to the underlying device.

		State 1: All writes to the device cause the underlying data to be backed up to
		the free (trimmed) area as needed in such a way as they can be restored.
		However, the writes, with one exception, then happen exactly as they would
		without dm_bow, so the device is always in a good final state. The exception is
		that sector 0 is used to keep a log of the latest changes, both to indicate that
		we are in this state and to allow rollback. See below for all details. If there
		isn't enough free space, writes are failed with -ENOSPC.

		State 2: The transition to state 2 triggers replacing the special sector 0 with
		the normal sector 0, and the freeing of all state information. dm_bow then
		becomes a pass-through driver, allowing the device to continue to be used with
		minimal performance impact.

		Usage
		=====
		dm-bow takes one command line parameter, the name of the underlying device.

		dm-bow will typically be used in the following way. dm-bow will be loaded with a
		suitable underlying device and the resultant device will be mounted. A file
		system trim will be issued via the FITRIM ioctl, then the device will be
		switched to state 1. The file system will now be used as normal. At some point,
		the changes can either be committed by switching to state 2, or rolled back by
		unmounting the file system, removing the dm-bow device and running the command
		line utility. Note that rebooting the device will be equivalent to unmounting
		and removing, but the command line utility must still be run

		Details of operation in state 1
		===============================

		dm_bow maintains a type for all sectors. A sector can be any of:

		SECTOR0
		SECTOR0_CURRENT
		UNCHANGED
		FREE
		CHANGED
		BACKUP

		SECTOR0 is the first sector on the device, and is used to hold the log of
		changes. This is the one exception.

		SECTOR0_CURRENT is a sector picked from the FREE sectors, and is where reads and
		writes from the true sector zero are redirected to. Note that like any backup
		sector, if the sector is written to directly, it must be moved again.

		UNCHANGED means that the sector has not been changed since we entered state 1.
		Thus if it is written to or trimmed, the contents must first be backed up.

		FREE means that the sector was trimmed in state 0 and has not yet been written
		to or used for backup. On being written to, a FREE sector is changed to CHANGED.

		CHANGED means that the sector has been modified, and can be further modified
		without further backup.

		BACKUP means that this is a free sector being used as a backup. On being written
		to, the contents must first be backed up again.

		All backup operations are logged to the first sector. The log sector has the
		format:
		--------------------------------------------------------
		\| Magic \| Count \| Sequence \| Log entry \| Log entry \| …
		--------------------------------------------------------

		Magic is a magic number. Count is the number of log entries. Sequence is 0
		initially. A log entry is

		-----------------------------------
		\| Source \| Dest \| Size \| Checksum \|
		-----------------------------------

		When SECTOR0 is full, the log sector is backed up and another empty log sector
		created with sequence number one higher. The first entry in any log entry with
		sequence > 0 therefore must be the log of the backing up of the previous log
		sector. Note that sequence is not strictly needed, but is a useful sanity check
		and potentially limits the time spent trying to restore a corrupted snapshot.

		On entering state 1, dm_bow has a list of free sectors. All other sectors are
		unchanged. Sector0_current is selected from the free sectors and the contents of
		sector 0 are copied there. The sector 0 is backed up, which triggers the first
		log entry to be written.

Documentation/filesystems/f2fs.txt

+2 −0

Original line number	Diff line number	Diff line
		@@ -126,6 +126,8 @@ disable_ext_identify Disable the extension list configured by mkfs, so f2fs
		does not aware of cold files such as media files.
		inline_xattr Enable the inline xattrs feature.
		noinline_xattr Disable the inline xattrs feature.
		inline_xattr_size=%u Support configuring inline xattr size, it depends on
		flexible inline xattr feature.
		inline_data Enable the inline data feature: New created small(<~3.4k)
		files can be written into inode block.
		inline_dentry Enable the inline dir feature: data in new created

Documentation/printk-formats.txt

+28 −3

Original line number	Diff line number	Diff line
		@@ -5,7 +5,6 @@ How to get printk format specifiers right
		:Author: Randy Dunlap <rdunlap@infradead.org>
		:Author: Andrew Murray <amurray@mpc-data.co.uk>


		Integer types
		=============

		@@ -45,6 +44,18 @@ return from vsnprintf.
		Raw pointer value SHOULD be printed with %p. The kernel supports
		the following extended format specifiers for pointer types:

		Pointer Types
		=============

		Pointers printed without a specifier extension (i.e unadorned %p) are
		hashed to give a unique identifier without leaking kernel addresses to user
		space. On 64 bit machines the first 32 bits are zeroed. If you _really_
		want the address see %px below.

		::

		%p abcdef12 or 00000000abcdef12

		Symbols/Function Pointers
		=========================

		@@ -85,18 +96,32 @@ Examples::
		printk("Faulted at %pS\n", (void *)regs->ip);
		printk(" %s%pB\n", (reliable ? "" : "? "), (void )stack);


		Kernel Pointers
		===============

		::

		%pK 0x01234567 or 0x0123456789abcdef
		%pK 01234567 or 0123456789abcdef

		For printing kernel pointers which should be hidden from unprivileged
		users. The behaviour of ``%pK`` depends on the ``kptr_restrict sysctl`` - see
		Documentation/sysctl/kernel.txt for more details.

		Unmodified Addresses
		====================

		::

		%px 01234567 or 0123456789abcdef

		For printing pointers when you _really_ want to print the address. Please
		consider whether or not you are leaking sensitive information about the
		Kernel layout in memory before printing pointers with %px. %px is
		functionally equivalent to %lx. %px is preferred to %lx because it is more
		uniquely grep'able. If, in the future, we need to modify the way the Kernel
		handles printing pointers it will be nice to be able to find the call
		sites.

		Struct Resources
		================

Makefile

+1 −1

Original line number	Diff line number	Diff line
		# SPDX-License-Identifier: GPL-2.0
		VERSION = 4
		PATCHLEVEL = 14
		SUBLEVEL = 108
		SUBLEVEL = 109
		EXTRAVERSION =
		NAME = Petit Gorille