# SPDX-License-Identifier: GPL-2.0## Block layer core configuration#menuconfig BLOCK       bool "Enable the block layer" if EXPERT       default y       select FS_IOMAP       select SBITMAP       help	 Provide block layer support for the kernel. 	 Disable this option to remove the block layer support from the	 kernel. This may be useful for embedded devices. 	 If this option is disabled: 	   - block device files will become unusable	   - some filesystems (such as ext3) will become unavailable. 	 Also, SCSI character devices and USB storage will be disabled since	 they make use of various block layer definitions and facilities. 	 Say Y here unless you know you really don't want to mount disks and	 suchlike. if BLOCK config BLOCK_LEGACY_AUTOLOAD	bool "Legacy autoloading support"	default y	help	  Enable loading modules and creating block device instances based on	  accesses through their device special file.  This is a historic Linux	  feature and makes no sense in a udev world where device files are	  created on demand, but scripts that manually create device nodes and	  then call losetup might rely on this behavior. config BLK_RQ_ALLOC_TIME	bool config BLK_CGROUP_RWSTAT	bool config BLK_CGROUP_PUNT_BIO	bool config BLK_DEV_BSG_COMMON	tristate config BLK_ICQ	bool config BLK_DEV_BSGLIB	bool "Block layer SG support v4 helper lib"	select BLK_DEV_BSG_COMMON	help	  Subsystems will normally enable this if needed. Users will not	  normally need to manually enable this. 	  If unsure, say N. config BLK_DEV_INTEGRITY	bool "Block layer data integrity support"	select CRC_T10DIF	select CRC64	help	Some storage devices allow extra information to be	stored/retrieved to help protect the data.  The block layer	data integrity option provides hooks which can be used by	filesystems to ensure better data integrity. 	Say yes here if you have a storage device that provides the	T10/SCSI Data Integrity Field or the T13/ATA External Path	Protection.  If in doubt, say N. config BLK_DEV_WRITE_MOUNTED	bool "Allow writing to mounted block devices"	default y	help	When a block device is mounted, writing to its buffer cache is very	likely going to cause filesystem corruption. It is also rather easy to	crash the kernel in this way since the filesystem has no practical way	of detecting these writes to buffer cache and verifying its metadata	integrity. However there are some setups that need this capability	like running fsck on read-only mounted root device, modifying some	features on mounted ext4 filesystem, and similar. If you say N, the	kernel will prevent processes from writing to block devices that are	mounted by filesystems which provides some more protection from runaway	privileged processes and generally makes it much harder to crash	filesystem drivers. Note however that this does not prevent	underlying device(s) from being modified by other means, e.g. by	directly submitting SCSI commands or through access to lower layers of	storage stack. If in doubt, say Y. The configuration can be overridden	with the bdev_allow_write_mounted boot option. config BLK_DEV_ZONED	bool "Zoned block device support"	help	Block layer zoned block device support. This option enables	support for ZAC/ZBC/ZNS host-managed and host-aware zoned block	devices. 	Say yes here if you have a ZAC, ZBC, or ZNS storage device. config BLK_DEV_THROTTLING	bool "Block layer bio throttling support"	depends on BLK_CGROUP	select BLK_CGROUP_RWSTAT	help	Block layer bio throttling support. It can be used to limit	the IO rate to a device. IO rate policies are per cgroup and	one needs to mount and use blkio cgroup controller for creating	cgroups and specifying per device IO rate policies. 	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. config BLK_WBT	bool "Enable support for block device writeback throttling"	help	Enabling this option enables the block layer to throttle buffered	background writeback from the VM, making it more smooth and having	less impact on foreground operations. The throttling is done	dynamically on an algorithm loosely based on CoDel, factoring in	the realtime performance of the disk. config BLK_WBT_MQ	bool "Enable writeback throttling by default"	default y	depends on BLK_WBT	help	Enable writeback throttling by default for request-based block devices. config BLK_CGROUP_IOLATENCY	bool "Enable support for latency based cgroup IO protection"	depends on BLK_CGROUP	help	Enabling this option enables the .latency interface for IO throttling.	The IO controller will attempt to maintain average IO latencies below	the configured latency target, throttling anybody with a higher latency	target than the victimized group. 	Note, this is an experimental interface and could be changed someday. config BLK_CGROUP_FC_APPID	bool "Enable support to track FC I/O Traffic across cgroup applications"	depends on BLK_CGROUP && NVME_FC	help	  Enabling this option enables the support to track FC I/O traffic across	  cgroup applications. It enables the Fabric and the storage targets to	  identify, monitor, and handle FC traffic based on VM tags by inserting	  application specific identification into the FC frame. config BLK_CGROUP_IOCOST	bool "Enable support for cost model based cgroup IO controller"	depends on BLK_CGROUP	select BLK_RQ_ALLOC_TIME	help	Enabling this option enables the .weight interface for cost	model based proportional IO control.  The IO controller	distributes IO capacity between different groups based on	their share of the overall weight distribution. config BLK_CGROUP_IOPRIO	bool "Cgroup I/O controller for assigning an I/O priority class"	depends on BLK_CGROUP	help	Enable the .prio interface for assigning an I/O priority class to	requests. The I/O priority class affects the order in which an I/O	scheduler and block devices process requests. Only some I/O schedulers	and some block devices support I/O priorities. config BLK_DEBUG_FS	bool "Block layer debugging information in debugfs"	default y	depends on DEBUG_FS	help	Include block layer debugging information in debugfs. This information	is mostly useful for kernel developers, but it doesn't incur any cost	at runtime. 	Unless you are building a kernel for a tiny system, you should	say Y here. config BLK_SED_OPAL	bool "Logic for interfacing with Opal enabled SEDs"	depends on KEYS	select PSERIES_PLPKS if PPC_PSERIES	select PSERIES_PLPKS_SED if PPC_PSERIES	help	Builds Logic for interfacing with Opal enabled controllers.	Enabling this option enables users to setup/unlock/lock	Locking ranges for SED devices using the Opal protocol. config BLK_INLINE_ENCRYPTION	bool "Enable inline encryption support in block layer"	help	  Build the blk-crypto subsystem. Enabling this lets the	  block layer handle encryption, so users can take	  advantage of inline encryption hardware if present. config BLK_INLINE_ENCRYPTION_FALLBACK	bool "Enable crypto API fallback for blk-crypto"	depends on BLK_INLINE_ENCRYPTION	select CRYPTO	select CRYPTO_SKCIPHER	help	  Enabling this lets the block layer handle inline encryption	  by falling back to the kernel crypto API when inline	  encryption hardware is not present. source "block/partitions/Kconfig" config BLK_PM	def_bool PM # do not use in new codeconfig BLOCK_HOLDER_DEPRECATED	bool config BLK_MQ_STACKING	bool config BLK_ERROR_INJECTION	bool "Enable block layer error injection"	select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL	help	  Enable inserting arbitrary block errors through a debugfs interface. 	  See Documentation/block/error-injection.rst for details. source "block/Kconfig.iosched" endif # BLOCK