rm(1): clarify that -P works only when blocks are updated in-place

Suggested by:	pjd, ivoras, arundel
This commit is contained in:
Ulrich Spörlein 2010-10-08 15:20:20 +00:00
parent 51c63dce86
commit a3800f8f0e
2 changed files with 6 additions and 6 deletions

View File

@ -32,7 +32,7 @@
.\" @(#)rm.1 8.5 (Berkeley) 12/5/94
.\" $FreeBSD$
.\"
.Dd October 3, 2010
.Dd October 8, 2010
.Dt RM 1
.Os
.Sh NAME
@ -229,8 +229,8 @@ command appeared in
.Sh BUGS
The
.Fl P
option assumes that the underlying file system is a fixed-block file
system.
UFS is a fixed-block file system, LFS is not.
option assumes that the underlying file system updates existing blocks
in-place and does not store new data in a new location.
This is true for UFS but not for ZFS, which is using a Copy-On-Write strategy.
In addition, only regular files are overwritten, other types of files
are not.

View File

@ -402,8 +402,8 @@ rm_file(char **argv)
* This is a cheap way to *really* delete files. Note that only regular
* files are deleted, directories (and therefore names) will remain.
* Also, this assumes a fixed-block file system (like FFS, or a V7 or a
* System V file system). In a logging file system, you'll have to have
* kernel support.
* System V file system). In a logging or COW file system, you'll have to
* have kernel support.
*/
int
rm_overwrite(char *file, struct stat *sbp)