cal: Update man page

[thirdparty/util-linux.git] / disk-utils / blockdev.8

diff --git a/disk-utils/blockdev.8 b/disk-utils/blockdev.8
index 2b3d64c88f3d5e0d876ea4b1273175e478c36042..5d85c01b791aec97e5a2b6d0873f16254054d792 100644 (file)
--- a/disk-utils/blockdev.8
+++ b/disk-utils/blockdev.8
@@ -1,4 +1,3 @@
-.\" -*- nroff -*-
 .\" Copyright 1998 Andries E. Brouwer (aeb@cwi.nl)
 .\" Copyright 2007 Karel Zak <kzak@redhat.com>
 .\"
@@ -10,21 +9,22 @@ blockdev \- call block device ioctls from the command line
 .B blockdev
 .RB [ \-q ]
 .RB [ \-v ]
-.IR command
-.RI [ command ...]
-.IR device
-.RI [ device ...]
+.I command
+.RI [ command \&...\&]
+.I device
+.RI [ device \&...\&]
 .br
 .B blockdev
 .B \-\-report
-.RI [ device ...]
+.RI [ device \&...\&]
+.br
+.B blockdev
+.RB \-h | \-V
 .SH DESCRIPTION
 The utility
 .B blockdev
 allows one to call block device ioctls from the command line.
 .SH OPTIONS
-.IP "\fB\-V\fP"
-Print version and exit.
 .IP "\fB\-q\fP"
 Be quiet.
 .IP "\fB\-v\fP"
@@ -33,6 +33,10 @@ Be verbose.
 Print a report for the specified device. It is possible to give multiple
 devices. If none is given, all devices which appear in /proc/partitions are
 shown. Note that the partition StartSec is in 512-byte sectors.
+.IP "\fB\-h\fR, \fB\-\-help\fR"
+Display help text and exit.
+.IP "\fB\-V\fR, \fB\-\-version\fR"
+Print version and exit.
 .SH COMMANDS
 It is possible to give multiple devices and multiple commands.
 .IP "\fB\-\-flushbufs\fP"
@@ -40,7 +44,9 @@ Flush buffers.
 .IP "\fB\-\-getalignoff\fP"
 Get alignment offset.
 .IP "\fB\-\-getbsz\fP"
-Print blocksize in bytes.
+Print blocksize in bytes.  This size does not describe device topology.  It's
+size used internally by kernel and it maybe modified (for example) by
+filesystem driver on mount.
 .IP "\fB\-\-getdiscardzeroes\fP"
 Get discard zeroes support status.
 .IP "\fB\-\-getfra\fP"
@@ -60,26 +66,28 @@ Get read-only. Print 1 if the device is read-only, 0 otherwise.
 .IP "\fB\-\-getsize64\fP"
 Print device size in bytes.
 .IP "\fB\-\-getsize\fP"
-Print device size (32-bit!) in sectors. Deprecated in favor of the --getsz option.
+Print device size (32-bit!) in sectors. Deprecated in favor of the \-\-getsz option.
 .IP "\fB\-\-getss\fP"
-Print sectorsize in bytes - usually 512.
+Print logical sector size in bytes \(en usually 512.
 .IP "\fB\-\-getsz\fP"
 Get size in 512-byte sectors.
 .IP "\fB\-\-rereadpt\fP"
 Reread partition table
 .IP "\fB\-\-setbsz\fP \fIbytes\fP"
-Set blocksize.
+Set blocksize. Note that the block size is specific to the current file
+descriptor opening the block device, so the change of block size only persists
+for as long as blockdev has the device open, and is lost once blockdev exits.
 .IP "\fB\-\-setfra\fP \fIsectors\fP"
-Set filesystem readahead (same like --setra on 2.6 kernels).
+Set filesystem readahead (same like \-\-setra on 2.6 kernels).
 .IP "\fB\-\-setra\fP \fIsectors\fP"
 Set readahead (in 512-byte sectors).
 .IP "\fB\-\-setro\fP"
-Set read-only.
+Set read-only. The currently active access to the device may not be affected by the change. For example
+filesystem already mounted in read-write mode will not be affected. The change applies after remount.
 .IP "\fB\-\-setrw\fP"
 Set read-write.
 .SH AUTHOR
-blockdev was written by Andries E. Brouwer and rewritten by Karel Zak.
+blockdev was written by Andries E.\& Brouwer and rewritten by Karel Zak.
 .SH AVAILABILITY
 The blockdev command is part of the util-linux package and is available from
-ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
-
+https://www.kernel.org/pub/linux/utils/util-linux/.