1# 2# Block layer core configuration 3# 4menuconfig BLOCK 5 bool "Enable the block layer" if EXPERT 6 default y 7 help 8 Provide block layer support for the kernel. 9 10 Disable this option to remove the block layer support from the 11 kernel. This may be useful for embedded devices. 12 13 If this option is disabled: 14 15 - block device files will become unusable 16 - some filesystems (such as ext3) will become unavailable. 17 18 Also, SCSI character devices and USB storage will be disabled since 19 they make use of various block layer definitions and facilities. 20 21 Say Y here unless you know you really don't want to mount disks and 22 suchlike. 23 24if BLOCK 25 26config LBDAF 27 bool "Support for large (2TB+) block devices and files" 28 depends on !64BIT 29 default y 30 help 31 Enable block devices or files of size 2TB and larger. 32 33 This option is required to support the full capacity of large 34 (2TB+) block devices, including RAID, disk, Network Block Device, 35 Logical Volume Manager (LVM) and loopback. 36 37 This option also enables support for single files larger than 38 2TB. 39 40 The ext4 filesystem requires that this feature be enabled in 41 order to support filesystems that have the huge_file feature 42 enabled. Otherwise, it will refuse to mount in the read-write 43 mode any filesystems that use the huge_file feature, which is 44 enabled by default by mke2fs.ext4. 45 46 The GFS2 filesystem also requires this feature. 47 48 If unsure, say Y. 49 50config BLK_DEV_BSG 51 bool "Block layer SG support v4" 52 default y 53 help 54 Saying Y here will enable generic SG (SCSI generic) v4 support 55 for any block device. 56 57 Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4 58 can handle complicated SCSI commands: tagged variable length cdbs 59 with bidirectional data transfers and generic request/response 60 protocols (e.g. Task Management Functions and SMP in Serial 61 Attached SCSI). 62 63 This option is required by recent UDEV versions to properly 64 access device serial numbers, etc. 65 66 If unsure, say Y. 67 68config BLK_DEV_BSGLIB 69 bool "Block layer SG support v4 helper lib" 70 default n 71 select BLK_DEV_BSG 72 help 73 Subsystems will normally enable this if needed. Users will not 74 normally need to manually enable this. 75 76 If unsure, say N. 77 78config BLK_DEV_INTEGRITY 79 bool "Block layer data integrity support" 80 select CRC_T10DIF if BLK_DEV_INTEGRITY 81 ---help--- 82 Some storage devices allow extra information to be 83 stored/retrieved to help protect the data. The block layer 84 data integrity option provides hooks which can be used by 85 filesystems to ensure better data integrity. 86 87 Say yes here if you have a storage device that provides the 88 T10/SCSI Data Integrity Field or the T13/ATA External Path 89 Protection. If in doubt, say N. 90 91config BLK_DEV_DAX 92 bool "Block device DAX support" 93 depends on FS_DAX 94 depends on BROKEN 95 help 96 When DAX support is available (CONFIG_FS_DAX) raw block 97 devices can also support direct userspace access to the 98 storage capacity via MMAP(2) similar to a file on a 99 DAX-enabled filesystem. However, the DAX I/O-path disables 100 some standard I/O-statistics, and the MMAP(2) path has some 101 operational differences due to bypassing the page 102 cache. If in doubt, say N. 103 104config BLK_DEV_THROTTLING 105 bool "Block layer bio throttling support" 106 depends on BLK_CGROUP=y 107 default n 108 ---help--- 109 Block layer bio throttling support. It can be used to limit 110 the IO rate to a device. IO rate policies are per cgroup and 111 one needs to mount and use blkio cgroup controller for creating 112 cgroups and specifying per device IO rate policies. 113 114 See Documentation/cgroups/blkio-controller.txt for more information. 115 116config BLK_CMDLINE_PARSER 117 bool "Block device command line partition parser" 118 default n 119 ---help--- 120 Enabling this option allows you to specify the partition layout from 121 the kernel boot args. This is typically of use for embedded devices 122 which don't otherwise have any standardized method for listing the 123 partitions on a block device. 124 125 See Documentation/block/cmdline-partition.txt for more information. 126 127menu "Partition Types" 128 129source "block/partitions/Kconfig" 130 131endmenu 132 133endif # BLOCK 134 135config BLOCK_COMPAT 136 bool 137 depends on BLOCK && COMPAT 138 default y 139 140source block/Kconfig.iosched 141