2 # Block layer core configuration
5 bool "Enable the block layer" if EXPERT
10 Provide block layer support for the kernel.
12 Disable this option to remove the block layer support from the
13 kernel. This may be useful for embedded devices.
15 If this option is disabled:
17 - block device files will become unusable
18 - some filesystems (such as ext3) will become unavailable.
20 Also, SCSI character devices and USB storage will be disabled since
21 they make use of various block layer definitions and facilities.
23 Say Y here unless you know you really don't want to mount disks and
29 bool "Support for large (2TB+) block devices and files"
33 Enable block devices or files of size 2TB and larger.
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.
39 This option also enables support for single files larger than
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.
48 The GFS2 filesystem also requires this feature.
52 config BLK_SCSI_REQUEST
56 bool "Block layer SG support v4"
58 select BLK_SCSI_REQUEST
60 Saying Y here will enable generic SG (SCSI generic) v4 support
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
69 This option is required by recent UDEV versions to properly
70 access device serial numbers, etc.
75 bool "Block layer SG support v4 helper lib"
78 select BLK_SCSI_REQUEST
80 Subsystems will normally enable this if needed. Users will not
81 normally need to manually enable this.
85 config BLK_DEV_INTEGRITY
86 bool "Block layer data integrity support"
87 select CRC_T10DIF if BLK_DEV_INTEGRITY
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.
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.
99 bool "Zoned block device support"
101 Block layer zoned block device support. This option enables
102 support for ZAC/ZBC host-managed and host-aware zoned block devices.
104 Say yes here if you have a ZAC or ZBC storage device.
106 config BLK_DEV_THROTTLING
107 bool "Block layer bio throttling support"
108 depends on BLK_CGROUP=y
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.
116 See Documentation/cgroups/blkio-controller.txt for more information.
118 config BLK_CMDLINE_PARSER
119 bool "Block device command line partition parser"
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.
127 See Documentation/block/cmdline-partition.txt for more information.
130 bool "Enable support for block device writeback throttling"
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.
140 bool "Single queue writeback throttling"
144 Enable writeback throttling by default on legacy single queue devices
147 bool "Multiqueue writeback throttling"
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.
156 bool "Block layer debugging information in debugfs"
160 Include block layer debugging information in debugfs. This information
161 is mostly useful for kernel developers, but it doesn't incur any cost
164 Unless you are building a kernel for a tiny system, you should
168 bool "Logic for interfacing with Opal enabled SEDs"
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.
174 menu "Partition Types"
176 source "block/partitions/Kconfig"
184 depends on BLOCK && COMPAT
189 depends on BLOCK && PCI
194 depends on BLOCK && VIRTIO
197 source block/Kconfig.iosched