block: adjust blkdev_issue_discard for swap

[linux-2.6.git] / block / Kconfig

diff --git a/block/Kconfig b/block/Kconfig
index 285935134bcd02cedf51cd1330ea1460aca4ca14..1ab7c15c8d7a58bc2df639a759a0b719bb2c25da 100644 (file)
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -5,14 +5,18 @@ menuconfig BLOCK
        bool "Enable the block layer" if EMBEDDED
        default y
        help
-        This permits the block layer to be removed from the kernel if it's not
-        needed (on some embedded devices for example).  If this option is
-        disabled, then blockdev files will become unusable and some
-        filesystems (such as ext3) will become unavailable.
+        Provide block layer support for the kernel.
 
-        This option will also disable SCSI character devices and USB storage
-        since they make use of various block layer definitions and
-        facilities.
+        Disable this option to remove the block layer support from the
+        kernel. This may be useful for embedded devices.
+
+        If this option is disabled:
+
+          - block device files will become unusable
+          - some filesystems (such as ext3) will become unavailable.
+
+        Also, SCSI character devices and USB storage will be disabled since
+        they make use of various block layer definitions and facilities.
 
         Say Y here unless you know you really don't want to mount disks and
         suchlike.
@@ -23,9 +27,20 @@ config LBD
        bool "Support for Large Block Devices"
        depends on !64BIT
        help
-         Say Y here if you want to attach large (bigger than 2TB) discs to
-         your machine, or if you want to have a raid or loopback device
-         bigger than 2TB.  Otherwise say N.
+         Enable block devices of size 2TB and larger.
+
+         This option is required to support the full capacity of large
+         (2TB+) block devices, including RAID, disk, Network Block Device,
+         Logical Volume Manager (LVM) and loopback.
+
+         For example, RAID devices are frequently bigger than the capacity
+         of the largest individual hard drive.
+
+         This option is not required if you have individual disk drives
+         which total 2TB+ and you are not aggregating the capacity into
+         a large block device (e.g. using RAID or LVM).
+
+         If unsure, say N.
 
 config BLK_DEV_IO_TRACE
        bool "Support for tracing block io actions"
@@ -33,22 +48,56 @@ config BLK_DEV_IO_TRACE
        select RELAY
        select DEBUG_FS
        help
-         Say Y here, if you want to be able to trace the block layer actions
+         Say Y here if you want to be able to trace the block layer actions
          on a given queue. Tracing allows you to see any traffic happening
-         on a block device queue. For more information (and the user space
-         support tools needed), fetch the blktrace app from:
+         on a block device queue. For more information (and the userspace
+         support tools needed), fetch the blktrace tools from:
 
-         git://brick.kernel.dk/data/git/blktrace.git
+         git://git.kernel.dk/blktrace.git
+
+         If unsure, say N.
 
 config LSF
        bool "Support for Large Single Files"
        depends on !64BIT
        help
-         Say Y here if you want to be able to handle very large files (bigger
-         than 2TB), otherwise say N.
+         Say Y here if you want to be able to handle very large files (2TB
+         and larger), otherwise say N.
 
          If unsure, say Y.
 
+config BLK_DEV_BSG
+       bool "Block layer SG support v4 (EXPERIMENTAL)"
+       depends on EXPERIMENTAL
+       ---help---
+         Saying Y here will enable generic SG (SCSI generic) v4 support
+         for any block device.
+
+         Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
+         can handle complicated SCSI commands: tagged variable length cdbs
+         with bidirectional data transfers and generic request/response
+         protocols (e.g. Task Management Functions and SMP in Serial
+         Attached SCSI).
+
+         If unsure, say N.
+
+config BLK_DEV_INTEGRITY
+       bool "Block layer data integrity support"
+       ---help---
+       Some storage devices allow extra information to be
+       stored/retrieved to help protect the data.  The block layer
+       data integrity option provides hooks which can be used by
+       filesystems to ensure better data integrity.
+
+       Say yes here if you have a storage device that provides the
+       T10/SCSI Data Integrity Field or the T13/ATA External Path
+       Protection.  If in doubt, say N.
+
 endif # BLOCK
 
+config BLOCK_COMPAT
+       bool
+       depends on BLOCK && COMPAT
+       default y
+
 source block/Kconfig.iosched