2 # Block layer core configuration
5 bool "Enable the block layer" if EXPERT
11 Provide block layer support for the kernel.
13 Disable this option to remove the block layer support from the
14 kernel. This may be useful for embedded devices.
16 If this option is disabled:
18 - block device files will become unusable
19 - some filesystems (such as ext3) will become unavailable.
21 Also, SCSI character devices and USB storage will be disabled since
22 they make use of various block layer definitions and facilities.
24 Say Y here unless you know you really don't want to mount disks and
30 bool "Support for large (2TB+) block devices and files"
34 Enable block devices or files of size 2TB and larger.
36 This option is required to support the full capacity of large
37 (2TB+) block devices, including RAID, disk, Network Block Device,
38 Logical Volume Manager (LVM) and loopback.
40 This option also enables support for single files larger than
43 The ext4 filesystem requires that this feature be enabled in
44 order to support filesystems that have the huge_file feature
45 enabled. Otherwise, it will refuse to mount in the read-write
46 mode any filesystems that use the huge_file feature, which is
47 enabled by default by mke2fs.ext4.
49 The GFS2 filesystem also requires this feature.
53 config BLK_SCSI_REQUEST
57 bool "Block layer SG support v4"
59 select BLK_SCSI_REQUEST
61 Saying Y here will enable generic SG (SCSI generic) v4 support
64 Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
65 can handle complicated SCSI commands: tagged variable length cdbs
66 with bidirectional data transfers and generic request/response
67 protocols (e.g. Task Management Functions and SMP in Serial
70 This option is required by recent UDEV versions to properly
71 access device serial numbers, etc.
76 bool "Block layer SG support v4 helper lib"
79 select BLK_SCSI_REQUEST
81 Subsystems will normally enable this if needed. Users will not
82 normally need to manually enable this.
86 config BLK_DEV_INTEGRITY
87 bool "Block layer data integrity support"
88 select CRC_T10DIF if BLK_DEV_INTEGRITY
90 Some storage devices allow extra information to be
91 stored/retrieved to help protect the data. The block layer
92 data integrity option provides hooks which can be used by
93 filesystems to ensure better data integrity.
95 Say yes here if you have a storage device that provides the
96 T10/SCSI Data Integrity Field or the T13/ATA External Path
97 Protection. If in doubt, say N.
100 bool "Zoned block device support"
102 Block layer zoned block device support. This option enables
103 support for ZAC/ZBC host-managed and host-aware zoned block devices.
105 Say yes here if you have a ZAC or ZBC storage device.
107 config BLK_DEV_THROTTLING
108 bool "Block layer bio throttling support"
109 depends on BLK_CGROUP=y
112 Block layer bio throttling support. It can be used to limit
113 the IO rate to a device. IO rate policies are per cgroup and
114 one needs to mount and use blkio cgroup controller for creating
115 cgroups and specifying per device IO rate policies.
117 See Documentation/cgroups/blkio-controller.txt for more information.
119 config BLK_CMDLINE_PARSER
120 bool "Block device command line partition parser"
123 Enabling this option allows you to specify the partition layout from
124 the kernel boot args. This is typically of use for embedded devices
125 which don't otherwise have any standardized method for listing the
126 partitions on a block device.
128 See Documentation/block/cmdline-partition.txt for more information.
131 bool "Enable support for block device writeback throttling"
134 Enabling this option enables the block layer to throttle buffered
135 background writeback from the VM, making it more smooth and having
136 less impact on foreground operations. The throttling is done
137 dynamically on an algorithm loosely based on CoDel, factoring in
138 the realtime performance of the disk.
141 bool "Single queue writeback throttling"
145 Enable writeback throttling by default on legacy single queue devices
148 bool "Multiqueue writeback throttling"
152 Enable writeback throttling by default on multiqueue devices.
153 Multiqueue currently doesn't have support for IO scheduling,
154 enabling this option is recommended.
157 bool "Block layer debugging information in debugfs"
161 Include block layer debugging information in debugfs. This information
162 is mostly useful for kernel developers, but it doesn't incur any cost
165 Unless you are building a kernel for a tiny system, you should
169 bool "Logic for interfacing with Opal enabled SEDs"
171 Builds Logic for interfacing with Opal enabled controllers.
172 Enabling this option enables users to setup/unlock/lock
173 Locking ranges for SED devices using the Opal protocol.
175 menu "Partition Types"
177 source "block/partitions/Kconfig"
185 depends on BLOCK && COMPAT
190 depends on BLOCK && PCI
195 depends on BLOCK && VIRTIO
198 source block/Kconfig.iosched