btrfs-progs: Convert man page for btrfs-image.

Convert man page for btrfs-image.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

Documentation/Makefile

@@ -6,7 +6,7 @@ MAN8_TXT += btrfs.txt
 MAN8_TXT += btrfs-convert.txt
 MAN8_TXT += btrfs-debug-tree.txt
 MAN8_TXT += btrfs-find-root.txt
-#MAN8_TXT += btrfs-image.txt
+MAN8_TXT += btrfs-image.txt
 #MAN8_TXT += btrfs-map-logical.txt
 #MAN8_TXT += btrfs-show-super.txt
 #MAN8_TXT += btrfstune.txt

Documentation/btrfs-image.txt

@@ -0,0 +1,70 @@
+btrfs-image(8)
+==============
+
+NAME
+----
+btrfs-image - create/restore an image of the filesystem
+
+SYNOPSIS
+--------
+'btrfs-image' [options] <source> <target>
+
+DESCRIPTION
+-----------
+'btrfs-image' is used to create an image of a btrfs filesystem.
+All data will be zeroed, but metadata and the like is preserved.
+
+Mainly used for debug purpose.
+
+OPTIONS
+-------
+-r::
+Restore metadump image. By default, this fixes super's chunk tree, by
+using 1 stripe pointing to primary device, so that file system can be
+restored by running tree log reply if possible. To restore without
+changing number of stripes in chunk tree check -o option.
+
+-c value::
+Compression level (0 ~ 9).
+
+-t value::
+Number of threads (1 ~ 32) to be used to process the image dump or restore.
+
+-o::
+Use the old restore method, this does not fixup the chunk tree so the restored
+file system will not be able to be mounted.
+
+-s::
+Sanitize the file names when generating the image. One -s means just
+generate random garbage, which means that the directory indexes won't match up
+since the hashes won't match with the garbage filenames. Using -ss will
+calculate a collision for the filename so that the hashes match, and if it
+can't calculate a collision then it will just generate garbage.  The collision
+calculator is very time and CPU intensive so only use it if you are having
+problems with your file system tree and need to have it mostly working.
+
+-w::
+Walk all the trees manually and copy any blocks that are referenced. Use this
+option if your extent tree is corrupted to make sure that all of the metadata is
+captured.
+
+EXIT STATUS
+-----------
+'btrfs-image' will return 0 if no error happened.
+If any problems happened, 1 will be returned.
+
+AUTHOR
+------
+Written by Shilong Wang and Wenruo Qu.
+
+COPYRIGHT
+---------
+Copyright (C) 2013 FUJITSU LIMITED.
+
+License GPLv2: GNU GPL version 2 <http://gnu.org/licenses/gpl.html>.
+
+This is free software: you are free  to  change  and  redistribute  it. There is NO WARRANTY, to the extent permitted by law.
+
+SEE ALSO
+--------
+`mkfs.btrfs`(8)