[Qemu-trivial] [PATCH 2/2] qemu-nbd: Minor texi updates

[Sitsofe Wheeler <sitsofe@yahoo.com>]

- Change some spacing.
- Remove duplicate entry for --format.
- Reword --discard documentation.
- Add --detect-zeroes documentation.

Signed-off-by: Sitsofe Wheeler <sitsofe@yahoo.com>
---
 qemu-nbd.texi | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 26cc985..ac4e613 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -1,6 +1,6 @@
 @example
 @c man begin SYNOPSIS
-usage: qemu-nbd [OPTION]...  @var{filename}
+usage: qemu-nbd [OPTION]... @var{filename}
 @c man end
 @end example
 
@@ -22,8 +22,9 @@ offset into the image
 interface to bind to (default @samp{0.0.0.0})
 @item -k, --socket=@var{path}
 Use a unix socket with path @var{path}
-@item -f, --format=@var{format}
-Set image format as @var{format}
+@item -f, --format=@var{fmt}
+force the use of the block driver for format @var{fmt} instead of
+auto-detecting
 @item -r, --read-only
 export read-only
 @item -P, --partition=@var{num}
@@ -44,17 +45,22 @@ the emulator's @code{-drive cache=...} option for allowed values.
 choose asynchronous I/O mode between @samp{threads} (the default)
 and @samp{native} (Linux only).
 @item --discard=@var{discard}
-toggles whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
-requests are ignored or passed to the filesystem.  The default is no
-(@samp{--discard=ignore}).
+controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
+requests are ignored or passed to the filesystem.  @var{discard} is one of
+@samp{ignore} (or @samp{off}), @samp{unmap} (or @samp{on}).  The default is
+@samp{ignore}.
+@item --detect-zeroes=@var{detect-zeroes}
+enables the automatic conversion of plain zero writes by the OS to driver
+specific optimized zero write commands.  @var{detect-zeroes} is one of
+@samp{off}, @samp{on} or @samp{unmap}.  @samp{unmap}
+converts a zero write to an unmap operation and can only be used if
+@var{discard} is set to @samp{unmap}.  The default is @samp{off}.
 @item -c, --connect=@var{dev}
 connect @var{filename} to NBD device @var{dev}
 @item -d, --disconnect
 disconnect the specified device
 @item -e, --shared=@var{num}
 device can be shared by @var{num} clients (default @samp{1})
-@item -f, --format=@var{fmt}
-force block driver for format @var{fmt} instead of auto-detecting
 @item -t, --persistent
 don't exit on the last connection
 @item -v, --verbose
-- 
2.4.3

-- 
Sitsofe | http://sucs.org/~sits/