btrfs: update Kconfig option descriptions

Expand what the options do and if they are OK to be enabled.

Signed-off-by: David Sterba <dsterba@suse.com>

Author: kdave

fs/btrfs/Kconfig

@@ -52,29 +52,34 @@ config BTRFS_FS_RUN_SANITY_TESTS
 	bool "Btrfs will run sanity tests upon loading"
 	depends on BTRFS_FS
 	help
-	  This will run some basic sanity tests on the free space cache
-	  code to make sure it is acting as it should.  These are mostly
-	  regression tests and are only really interesting to btrfs
-	  developers.
+	  This will run sanity tests for core functionality like free space,
+	  extent maps, extent io, extent buffers, inodes, qgroups and others,
+	  at module load time.  These are mostly regression tests and are only
+	  interesting to developers.
 
 	  If unsure, say N.
 
 config BTRFS_DEBUG
 	bool "Btrfs debugging support"
 	depends on BTRFS_FS
 	help
-	  Enable run-time debugging support for the btrfs filesystem. This may
-	  enable additional and expensive checks with negative impact on
-	  performance, or export extra information via sysfs.
+	  Enable run-time debugging support for the btrfs filesystem.
+
+	  Additional potentially expensive checks, debugging functionality or
+	  sysfs exported information is enabled, like leak checks of internal
+	  objects, optional forced space fragmentation and /sys/fs/btrfs/debug .
+	  This has negative impact on performance.
 
 	  If unsure, say N.
 
 config BTRFS_ASSERT
 	bool "Btrfs assert support"
 	depends on BTRFS_FS
 	help
-	  Enable run-time assertion checking.  This will result in panics if
-	  any of the assertions trip.  This is meant for btrfs developers only.
+	  Enable run-time assertion checking. Additional safety checks are
+	  done, simple enough not to affect performance but verify invariants
+	  and assumptions of code to run properly. This may result in panics,
+	  and is meant for developers but can be enabled in general.
 
 	  If unsure, say N.