btrfs-progs: update docs for inspect-internal dump-super

Signed-off-by: Alexander Fougner <fougner89@gmail.com>
[ minor formatting updates ]
Signed-off-by: David Sterba <dsterba@suse.com>

Documentation/btrfs-inspect-internal.asciidoc

@@ -87,6 +87,42 @@ subvolume itself return it's own tree id (ie. subvol id)
 NOTE: The result is undefined for the so-called empty subvolumes (identified by
 inode number 2), but such subvolume does not contain any files anyway
 
+*show-super* [options] <device> [device...]::
+(needs root privileges)
++
+Show btrfs superblock information stored in devices.
+It is used to print the information of superblock,
+you can specify which mirror to print out.
++
+By default, every device's first superblock will be printed out.
++
+Mainly used for debug purpose.
++
+`Options`
++
+-f::::
+Print full superblock information.
++
+Including the system chunk array and backup roots.
++
+-a::::
+Print information of all superblocks.
++
+If this option is given, '-i' option will be ignored.
++
+-i <super_mirror>::::
+Specify which mirror to print out.
++
+<super_mirror> is between 0 and 2.
+If several '-i <super_mirror>' are given, only the last one is valid.
++
+-F::::
+Attempt to print the superblock even if no superblock magic is found.  May end
+badly.
+-s <bytenr>::::
+specifiy offset to a superblock in a non-standard location at 'bytenr', useful
+for debugging (disables the '-f' option)
+
 *subvolid-resolve* <subvolid> <path>::
 (needs root privileges)
 +

btrfs-completion

@@ -36,7 +36,7 @@ _btrfs()
     commands_device='scan add delete remove ready stats usage'
     commands_scrub='start cancel resume status'
     commands_rescue='chunk-recover super-recover'
-    commands_inspect_internal='inode-resolve logical-resolve subvolid-resolve rootid min-dev-size dump-tree'
+    commands_inspect_internal='inode-resolve logical-resolve subvolid-resolve rootid min-dev-size dump-tree dump-super'
     commands_property='get set list'
     commands_quota='enable disable rescan'
     commands_qgroup='assign remove create destroy show limit'