Btrfs: add config option to enable btrfs integrity check

Added the BTRFS_FS_CHECK_INTEGRITY option to Kconfig. It depends on
BTRFS_FS.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>

diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index ecb9fd3..d33f01c 100644 (file)
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -31,3 +31,22 @@ config BTRFS_FS_POSIX_ACL
          Linux website <http://acl.bestbits.at/>.
 
          If you don't know what Access Control Lists are, say N
+
+config BTRFS_FS_CHECK_INTEGRITY
+       bool "Btrfs with integrity check tool compiled in (DANGEROUS)"
+       depends on BTRFS_FS
+       help
+         Adds code that examines all block write requests (including
+         writes of the super block). The goal is to verify that the
+         state of the filesystem on disk is always consistent, i.e.,
+         after a power-loss or kernel panic event the filesystem is
+         in a consistent state.
+
+         If the integrity check tool is included and activated in
+         the mount options, plenty of kernel memory is used, and
+         plenty of additional CPU cycles are spent. Enabling this
+         functionality is not intended for normal use.
+
+         In most cases, unless you are a btrfs developer who needs
+         to verify the integrity of (super)-block write requests
+         during the run of a regression test, say N