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_DEV_BSG 53 bool "Block layer SG support v4" 54 default y 55 help 56 Saying Y here will enable generic SG (SCSI generic) v4 support 57 for any block device. 58 59 Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4 60 can handle complicated SCSI commands: tagged variable length cdbs 61 with bidirectional data transfers and generic request/response 62 protocols (e.g. Task Management Functions and SMP in Serial 63 Attached SCSI). 64 65 This option is required by recent UDEV versions to properly 66 access device serial numbers, etc. 67 68 If unsure, say Y. 69 70config BLK_DEV_BSGLIB 71 bool "Block layer SG support v4 helper lib" 72 default n 73 select BLK_DEV_BSG 74 help 75 Subsystems will normally enable this if needed. Users will not 76 normally need to manually enable this. 77 78 If unsure, say N. 79 80config BLK_DEV_INTEGRITY 81 bool "Block layer data integrity support" 82 select CRC_T10DIF if BLK_DEV_INTEGRITY 83 ---help--- 84 Some storage devices allow extra information to be 85 stored/retrieved to help protect the data. The block layer 86 data integrity option provides hooks which can be used by 87 filesystems to ensure better data integrity. 88 89 Say yes here if you have a storage device that provides the 90 T10/SCSI Data Integrity Field or the T13/ATA External Path 91 Protection. If in doubt, say N. 92 93config BLK_DEV_ZONED 94 bool "Zoned block device support" 95 ---help--- 96 Block layer zoned block device support. This option enables 97 support for ZAC/ZBC host-managed and host-aware zoned block devices. 98 99 Say yes here if you have a ZAC or ZBC storage device. 100 101config BLK_DEV_THROTTLING 102 bool "Block layer bio throttling support" 103 depends on BLK_CGROUP=y 104 default n 105 ---help--- 106 Block layer bio throttling support. It can be used to limit 107 the IO rate to a device. IO rate policies are per cgroup and 108 one needs to mount and use blkio cgroup controller for creating 109 cgroups and specifying per device IO rate policies. 110 111 See Documentation/cgroups/blkio-controller.txt for more information. 112 113config BLK_CMDLINE_PARSER 114 bool "Block device command line partition parser" 115 default n 116 ---help--- 117 Enabling this option allows you to specify the partition layout from 118 the kernel boot args. This is typically of use for embedded devices 119 which don't otherwise have any standardized method for listing the 120 partitions on a block device. 121 122 See Documentation/block/cmdline-partition.txt for more information. 123 124config BLK_WBT 125 bool "Enable support for block device writeback throttling" 126 default n 127 ---help--- 128 Enabling this option enables the block layer to throttle buffered 129 background writeback from the VM, making it more smooth and having 130 less impact on foreground operations. The throttling is done 131 dynamically on an algorithm loosely based on CoDel, factoring in 132 the realtime performance of the disk. 133 134config BLK_WBT_SQ 135 bool "Single queue writeback throttling" 136 default n 137 depends on BLK_WBT 138 ---help--- 139 Enable writeback throttling by default on legacy single queue devices 140 141config BLK_WBT_MQ 142 bool "Multiqueue writeback throttling" 143 default y 144 depends on BLK_WBT 145 ---help--- 146 Enable writeback throttling by default on multiqueue devices. 147 Multiqueue currently doesn't have support for IO scheduling, 148 enabling this option is recommended. 149 150menu "Partition Types" 151 152source "block/partitions/Kconfig" 153 154endmenu 155 156endif # BLOCK 157 158config BLOCK_COMPAT 159 bool 160 depends on BLOCK && COMPAT 161 default y 162 163config BLK_MQ_PCI 164 bool 165 depends on BLOCK && PCI 166 default y 167 168source block/Kconfig.iosched 169