db29a6b496
Enable by default support for large devices and files (CONFIG_LBD): - With 1TB disks being a commodity hardware it is quite easy to hit 2TB limitation while building RAIDs etc. and many distros have been using CONFIG_LBD=y by default already (at least Fedora 10 and openSUSE 11.1). - This should also prevent a subtle ext4 filesystem compatibility issue: mke2fs.ext4 defaults to creating filesystems with huge_files feature enabled and such filesystems cannot be later mounted read-write on machines with CONFIG_LBD=n (it should be quite easy to hit this issue when trying to use filesystem created using distro kernel on system running the self-build kernel, think about USB disk enclosures & co.). While at it: - Clarify config option help text w.r.t. mounting ext4 filesystems (they can be mounted with CONFIG_LBD=n but in the read-only mode). Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
85 lines
2.5 KiB
Plaintext
85 lines
2.5 KiB
Plaintext
#
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# Block layer core configuration
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#
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menuconfig BLOCK
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bool "Enable the block layer" if EMBEDDED
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default y
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help
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Provide block layer support for the kernel.
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Disable this option to remove the block layer support from the
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kernel. This may be useful for embedded devices.
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If this option is disabled:
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- block device files will become unusable
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- some filesystems (such as ext3) will become unavailable.
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Also, SCSI character devices and USB storage will be disabled since
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they make use of various block layer definitions and facilities.
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Say Y here unless you know you really don't want to mount disks and
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suchlike.
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if BLOCK
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config LBD
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bool "Support for large block devices and files"
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depends on !64BIT
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default y
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help
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Enable block devices or files of size 2TB and larger.
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This option is required to support the full capacity of large
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(2TB+) block devices, including RAID, disk, Network Block Device,
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Logical Volume Manager (LVM) and loopback.
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This option also enables support for single files larger than
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2TB.
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The ext4 filesystem requires that this feature be enabled in
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order to support filesystems that have the huge_file feature
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enabled. Otherwise, it will refuse to mount in the read-write
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mode any filesystems that use the huge_file feature, which is
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enabled by default by mke2fs.ext4.
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The GFS2 filesystem also requires this feature.
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If unsure, say Y.
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config BLK_DEV_BSG
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bool "Block layer SG support v4 (EXPERIMENTAL)"
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depends on EXPERIMENTAL
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---help---
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Saying Y here will enable generic SG (SCSI generic) v4 support
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for any block device.
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Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
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can handle complicated SCSI commands: tagged variable length cdbs
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with bidirectional data transfers and generic request/response
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protocols (e.g. Task Management Functions and SMP in Serial
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Attached SCSI).
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If unsure, say N.
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config BLK_DEV_INTEGRITY
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bool "Block layer data integrity support"
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---help---
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Some storage devices allow extra information to be
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stored/retrieved to help protect the data. The block layer
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data integrity option provides hooks which can be used by
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filesystems to ensure better data integrity.
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Say yes here if you have a storage device that provides the
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T10/SCSI Data Integrity Field or the T13/ATA External Path
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Protection. If in doubt, say N.
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endif # BLOCK
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config BLOCK_COMPAT
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bool
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depends on BLOCK && COMPAT
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default y
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source block/Kconfig.iosched
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