1# 2# Block layer core configuration 3# 4menuconfig BLOCK 5 bool "Enable the block layer" if EXPERT 6 default y 7 select SBITMAP 8 select SRCU 9 help 10 Provide block layer support for the kernel. 11 12 Disable this option to remove the block layer support from the 13 kernel. This may be useful for embedded devices. 14 15 If this option is disabled: 16 17 - block device files will become unusable 18 - some filesystems (such as ext3) will become unavailable. 19 20 Also, SCSI character devices and USB storage will be disabled since 21 they make use of various block layer definitions and facilities. 22 23 Say Y here unless you know you really don't want to mount disks and 24 suchlike. 25 26if BLOCK 27 28config LBDAF 29 bool "Support for large (2TB+) block devices and files" 30 depends on !64BIT 31 default y 32 help 33 Enable block devices or files of size 2TB and larger. 34 35 This option is required to support the full capacity of large 36 (2TB+) block devices, including RAID, disk, Network Block Device, 37 Logical Volume Manager (LVM) and loopback. 38 39 This option also enables support for single files larger than 40 2TB. 41 42 The ext4 filesystem requires that this feature be enabled in 43 order to support filesystems that have the huge_file feature 44 enabled. Otherwise, it will refuse to mount in the read-write 45 mode any filesystems that use the huge_file feature, which is 46 enabled by default by mke2fs.ext4. 47 48 The GFS2 filesystem also requires this feature. 49 50 If unsure, say Y. 51 52config BLK_SCSI_REQUEST 53 bool 54 55config BLK_DEV_BSG 56 bool "Block layer SG support v4" 57 default y 58 select BLK_SCSI_REQUEST 59 help 60 Saying Y here will enable generic SG (SCSI generic) v4 support 61 for any block device. 62 63 Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4 64 can handle complicated SCSI commands: tagged variable length cdbs 65 with bidirectional data transfers and generic request/response 66 protocols (e.g. Task Management Functions and SMP in Serial 67 Attached SCSI). 68 69 This option is required by recent UDEV versions to properly 70 access device serial numbers, etc. 71 72 If unsure, say Y. 73 74config BLK_DEV_BSGLIB 75 bool "Block layer SG support v4 helper lib" 76 default n 77 select BLK_DEV_BSG 78 select BLK_SCSI_REQUEST 79 help 80 Subsystems will normally enable this if needed. Users will not 81 normally need to manually enable this. 82 83 If unsure, say N. 84 85config BLK_DEV_INTEGRITY 86 bool "Block layer data integrity support" 87 select CRC_T10DIF if BLK_DEV_INTEGRITY 88 ---help--- 89 Some storage devices allow extra information to be 90 stored/retrieved to help protect the data. The block layer 91 data integrity option provides hooks which can be used by 92 filesystems to ensure better data integrity. 93 94 Say yes here if you have a storage device that provides the 95 T10/SCSI Data Integrity Field or the T13/ATA External Path 96 Protection. If in doubt, say N. 97 98config BLK_DEV_ZONED 99 bool "Zoned block device support" 100 ---help--- 101 Block layer zoned block device support. This option enables 102 support for ZAC/ZBC host-managed and host-aware zoned block devices. 103 104 Say yes here if you have a ZAC or ZBC storage device. 105 106config BLK_DEV_THROTTLING 107 bool "Block layer bio throttling support" 108 depends on BLK_CGROUP=y 109 default n 110 ---help--- 111 Block layer bio throttling support. It can be used to limit 112 the IO rate to a device. IO rate policies are per cgroup and 113 one needs to mount and use blkio cgroup controller for creating 114 cgroups and specifying per device IO rate policies. 115 116 See Documentation/cgroups/blkio-controller.txt for more information. 117 118config BLK_CMDLINE_PARSER 119 bool "Block device command line partition parser" 120 default n 121 ---help--- 122 Enabling this option allows you to specify the partition layout from 123 the kernel boot args. This is typically of use for embedded devices 124 which don't otherwise have any standardized method for listing the 125 partitions on a block device. 126 127 See Documentation/block/cmdline-partition.txt for more information. 128 129config BLK_WBT 130 bool "Enable support for block device writeback throttling" 131 default n 132 ---help--- 133 Enabling this option enables the block layer to throttle buffered 134 background writeback from the VM, making it more smooth and having 135 less impact on foreground operations. The throttling is done 136 dynamically on an algorithm loosely based on CoDel, factoring in 137 the realtime performance of the disk. 138 139config BLK_WBT_SQ 140 bool "Single queue writeback throttling" 141 default n 142 depends on BLK_WBT 143 ---help--- 144 Enable writeback throttling by default on legacy single queue devices 145 146config BLK_WBT_MQ 147 bool "Multiqueue writeback throttling" 148 default y 149 depends on BLK_WBT 150 ---help--- 151 Enable writeback throttling by default on multiqueue devices. 152 Multiqueue currently doesn't have support for IO scheduling, 153 enabling this option is recommended. 154 155config BLK_DEBUG_FS 156 bool "Block layer debugging information in debugfs" 157 default y 158 depends on DEBUG_FS 159 ---help--- 160 Include block layer debugging information in debugfs. This information 161 is mostly useful for kernel developers, but it doesn't incur any cost 162 at runtime. 163 164 Unless you are building a kernel for a tiny system, you should 165 say Y here. 166 167config BLK_SED_OPAL 168 bool "Logic for interfacing with Opal enabled SEDs" 169 ---help--- 170 Builds Logic for interfacing with Opal enabled controllers. 171 Enabling this option enables users to setup/unlock/lock 172 Locking ranges for SED devices using the Opal protocol. 173 174menu "Partition Types" 175 176source "block/partitions/Kconfig" 177 178endmenu 179 180endif # BLOCK 181 182config BLOCK_COMPAT 183 bool 184 depends on BLOCK && COMPAT 185 default y 186 187config BLK_MQ_PCI 188 bool 189 depends on BLOCK && PCI 190 default y 191 192config BLK_MQ_VIRTIO 193 bool 194 depends on BLOCK && VIRTIO 195 default y 196 197source block/Kconfig.iosched 198