2 # Block layer core configuration
5 bool "Enable the block layer" if EMBEDDED
8 Provide block layer support for the kernel.
10 Disable this option to remove the block layer support from the
11 kernel. This may be useful for embedded devices.
13 If this option is disabled:
15 - block device files will become unusable
16 - some filesystems (such as ext3) will become unavailable.
18 Also, SCSI character devices and USB storage will be disabled since
19 they make use of various block layer definitions and facilities.
21 Say Y here unless you know you really don't want to mount disks and
27 bool "Support for large block devices and files"
30 Enable block devices or files of size 2TB and larger.
32 This option is required to support the full capacity of large
33 (2TB+) block devices, including RAID, disk, Network Block Device,
34 Logical Volume Manager (LVM) and loopback.
36 This option also enables support for single files larger than
39 The ext4 filesystem requires that this feature be enabled in
40 order to support filesystems that have the huge_file feature
41 enabled. Otherwise, it will refuse to mount any filesystems
42 that use the huge_file feature, which is enabled by default
43 by mke2fs.ext4. The GFS2 filesystem also requires this feature.
47 config BLK_DEV_IO_TRACE
48 bool "Support for tracing block io actions"
56 Say Y here if you want to be able to trace the block layer actions
57 on a given queue. Tracing allows you to see any traffic happening
58 on a block device queue. For more information (and the userspace
59 support tools needed), fetch the blktrace tools from:
61 git://git.kernel.dk/blktrace.git
63 Tracing also is possible using the ftrace interface, e.g.:
65 echo 1 > /sys/block/sda/sda1/trace/enable
66 echo blk > /sys/kernel/debug/tracing/current_tracer
67 cat /sys/kernel/debug/tracing/trace_pipe
72 bool "Block layer SG support v4 (EXPERIMENTAL)"
73 depends on EXPERIMENTAL
75 Saying Y here will enable generic SG (SCSI generic) v4 support
78 Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
79 can handle complicated SCSI commands: tagged variable length cdbs
80 with bidirectional data transfers and generic request/response
81 protocols (e.g. Task Management Functions and SMP in Serial
86 config BLK_DEV_INTEGRITY
87 bool "Block layer data integrity support"
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.
102 depends on BLOCK && COMPAT
105 source block/Kconfig.iosched