btrfs-progs: doc: document btrfs-select-super(8)

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/Documentation/Makefile.in b/Documentation/Makefile.in
index 0c8b5ba..b03eaf2 100644 (file)
--- a/Documentation/Makefile.in
+++ b/Documentation/Makefile.in
@@ -9,6 +9,7 @@ MAN8_TXT += btrfs-find-root.asciidoc
 MAN8_TXT += btrfs-image.asciidoc
 MAN8_TXT += btrfs-map-logical.asciidoc
 MAN8_TXT += btrfs-show-super.asciidoc
+MAN8_TXT += btrfs-select-super.asciidoc
 MAN8_TXT += btrfstune.asciidoc
 MAN8_TXT += fsck.btrfs.asciidoc
 MAN8_TXT += mkfs.btrfs.asciidoc

diff --git a/Documentation/btrfs-select-super.asciidoc b/Documentation/btrfs-select-super.asciidoc
new file mode 100644 (file)
index 0000000..a8d7ef0
--- /dev/null
+++ b/Documentation/btrfs-select-super.asciidoc
@@ -0,0 +1,29 @@
+btrfs-select-super(8)
+=====================
+
+NAME
+----
+btrfs-select-super - overwrite superblock with a backup
+
+SYNOPSIS
+--------
+*btrfs-select-super* -s number dev
+
+DESCRIPTION
+-----------
+*btrfs-select-super* destructively overwrites all copies of the superblock
+with a specified copy.  This helps with certain cases of damage, especially
+when barriers were disabled during a power failure.  You can find a valid
+copy of the superblock with *btrfs check -s*.
+
+The filesystem specified by `dev` must not be mounted.
+
+OPTIONS
+-------
+-s|--super <superblock>::
+use <superblock>th superblock copy, valid values are 0 up to 2 if the
+respective superblock offset is within the filesystem
+
+SEE ALSO
+--------
+`btrfsck check`(8)