From b2aa8b2a98fcd6f4e0abd19b3a2f72b4705aa640 Mon Sep 17 00:00:00 2001 From: Jens Schweikhardt Date: Thu, 10 Oct 2002 19:16:10 +0000 Subject: [PATCH] Document that write(2) et al can return EROFS for attempts to write the disk label area. PR: 43891 Submitted by: Diomidis D. Spinellis MFC after: 3 days --- lib/libc/sys/write.2 | 7 +++++++ sbin/bsdlabel/bsdlabel.8 | 5 ++++- sbin/disklabel/disklabel.8 | 5 ++++- 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/lib/libc/sys/write.2 b/lib/libc/sys/write.2 index d8a417756672..729a4d067bf7 100644 --- a/lib/libc/sys/write.2 +++ b/lib/libc/sys/write.2 @@ -171,6 +171,13 @@ A signal interrupted the write before it could be completed. .It Bq Er EAGAIN The file was marked for non-blocking I/O, and no data could be written immediately. +.It Bq Er EROFS +An attempt was made to write over a disk label area at the beginning +of a slice. +Use +.Xr disklabel 8 +.Fl W +to enable writing on the disk label area. .El .Pp In addition, diff --git a/sbin/bsdlabel/bsdlabel.8 b/sbin/bsdlabel/bsdlabel.8 index 32ed01cafd28..7c71bd7920fc 100644 --- a/sbin/bsdlabel/bsdlabel.8 +++ b/sbin/bsdlabel/bsdlabel.8 @@ -314,7 +314,10 @@ useful to see how a partitioning scheme will work out for a specific disk. .Ss Enabling and disabling writing to the disk label area .Pp By default, it is not possible to write to the disk label area at the beginning -of a disk. The disk driver silently ignores any attempt to do so. If you need +of a disk. The disk driver arranges for +.Xr write 2 +and similar system calls +to return EROFS on any attempt to do so. If you need to write to this area (for example, to obliterate the label), use the form .Pp .Nm diff --git a/sbin/disklabel/disklabel.8 b/sbin/disklabel/disklabel.8 index 32ed01cafd28..7c71bd7920fc 100644 --- a/sbin/disklabel/disklabel.8 +++ b/sbin/disklabel/disklabel.8 @@ -314,7 +314,10 @@ useful to see how a partitioning scheme will work out for a specific disk. .Ss Enabling and disabling writing to the disk label area .Pp By default, it is not possible to write to the disk label area at the beginning -of a disk. The disk driver silently ignores any attempt to do so. If you need +of a disk. The disk driver arranges for +.Xr write 2 +and similar system calls +to return EROFS on any attempt to do so. If you need to write to this area (for example, to obliterate the label), use the form .Pp .Nm