git: a5ad360ff9b7 - main - rc: Remove rc_fast_and_loose

The branch main has been updated by 0mp:

URL: https://cgit.FreeBSD.org/src/commit/?id=a5ad360ff9b7fb2ef3f7f31b8c29c332026b0e01

commit a5ad360ff9b7fb2ef3f7f31b8c29c332026b0e01
Author:     Mateusz Piotrowski <0mp@FreeBSD.org>
AuthorDate: 2024-10-23 12:57:29 +0000
Commit:     Mateusz Piotrowski <0mp@FreeBSD.org>
CommitDate: 2024-10-28 21:10:49 +0000

    rc: Remove rc_fast_and_loose
    
    The rc_fast_and_loose variable allowed rc(8) to start services
    by sourcing them into rc's own shell environment. Normally, each rc
    service script is started by being sourced into its own subshell
    instead.  The feature was meant to speed up rc(8) by avoiding the extra
    forking necessary to spawn subshells.
    
    In practice, the feature has been broken for a long time now. One of the
    reasons is that some rc service scripts call the exit builtin to return
    non-zero error codes, which not only terminates the service subshell
    but also rc(8) when rc_fast_and_loose is enabled. For example,
    a system running any of the supported FreeBSD releases
    with rc_fast_and_loose=yes would abort rc(8) as early as rc.d/hostid,
    due to an "exit 0".
    
    Fixing rc_fast_and_loose support would require rewriting some rc scripts
    to support being sourced directly into rc(8) process. This would muddy
    the code base and also would prove difficult to maintain long term
    as this is simply not how rc(8) users write scripts. The potential
    performance benefits are unlikely to be significant even for use cases
    such as Morello under qemu.
    
    Instead, remove support for rc_fast_and_loose completely from rc(8)
    and inform users about the change.
    
    PR:             282255
    Reviewed by:    brooks, christos, mhorne
    Approved by:    christos (mentor), markj (mentor)
    MFC after:      2 weeks
    Relnotes:       yes
    Differential Revision:  https://reviews.freebsd.org/D47264
---
 UPDATING                 |  7 +++++++
 libexec/rc/rc.subr       | 20 ++------------------
 share/man/man8/rc.subr.8 | 36 +++++++++++-------------------------
 3 files changed, 20 insertions(+), 43 deletions(-)

diff --git a/UPDATING b/UPDATING
index c2e7a658c65e..1fb14a96880b 100644
--- a/UPDATING
+++ b/UPDATING
@@ -27,6 +27,13 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 15.x IS SLOW:
 	world, or to merely disable the most expensive debugging functionality
 	at runtime, run "ln -s 'abort:false,junk:false' /etc/malloc.conf".)
 
+20241025:
+	The support for the rc_fast_and_loose variable has been removed from
+	rc.subr(8). Users setting rc_fast_and_loose on their systems are
+	advised to make sure their customizations to rc service scripts
+	do not depend on having a single shell environment shared across
+	all the rc service scripts during booting and shutdown.
+
 20241013:
 	The ciss driver was updated to cope better with hotplug events that
 	caused it to panic before, and to support more than 48 drives attached
diff --git a/libexec/rc/rc.subr b/libexec/rc/rc.subr
index 58e30c897897..dc2cc06bb806 100644
--- a/libexec/rc/rc.subr
+++ b/libexec/rc/rc.subr
@@ -1798,9 +1798,6 @@ _run_rc_killcmd()
 #	return value from the script.
 #	If `file' ends with `.sh' and lives in /etc/rc.d, ignore it as it's
 #	an old-style startup file.
-#	If `file' ends with `.sh' and does not live in /etc/rc.d, it's sourced
-#	into the current environment if $rc_fast_and_loose is set; otherwise
-#	it is run as a child process.
 #	If `file' appears to be a backup or scratch file, ignore it.
 #	Otherwise if it is executable run as a child process.
 #
@@ -1836,8 +1833,6 @@ run_rc_script()
 
 			if [ -n "$rc_boottrace" ]; then
 				boottrace_fn "$_file" "$_arg"
-			elif [ -n "$rc_fast_and_loose" ]; then
-				set $_arg; . $_file
 			else
 				( trap "echo Script $_file interrupted >&2 ; kill -QUIT $$" 3
 				  trap "echo Script $_file interrupted >&2 ; exit 1" 2
@@ -1909,19 +1904,8 @@ boottrace_fn()
 	_file=$1
 	_arg=$2
 
-	if [ -n "$rc_fast_and_loose" ]; then
-		boottrace_sysctl "$_file start"
-		set $_arg; . $_file
-		boottrace_sysctl "$_file done"
-	else
-		_boot="${_boot}" rc_fast="${rc_fast}" autoboot="${autoboot}" \
-		    $boottrace_cmd "$_file" "$_arg"
-	fi
-}
-
-boottrace_sysctl()
-{
-	${SYSCTL} kern.boottrace.boottrace="$1"
+	_boot="${_boot}" rc_fast="${rc_fast}" autoboot="${autoboot}" \
+	    $boottrace_cmd "$_file" "$_arg"
 }
 
 #
diff --git a/share/man/man8/rc.subr.8 b/share/man/man8/rc.subr.8
index 36d7d4543e52..1fd5041cecd8 100644
--- a/share/man/man8/rc.subr.8
+++ b/share/man/man8/rc.subr.8
@@ -27,7 +27,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd September 22, 2024
+.Dd October 23, 2024
 .Dt RC.SUBR 8
 .Os
 .Sh NAME
@@ -1017,41 +1017,27 @@ and
 to enable tracing if any of those tags appear in
 .Va DEBUG_SH .
 .Pp
-The startup behaviour of
+.Ic run_rc_script
+executes
 .Ar file
-depends upon the following checks:
+unless:
 .Bl -enum
 .It
-If
 .Ar file
 ends in
-.Pa .sh ,
-it is sourced into the current shell.
+.Pa .sh
+and lives in
+.Pa /etc/rc.d .
 .It
-If
 .Ar file
 appears to be a backup or scratch file
-(e.g., with a suffix of
-.Pa ~ , # , .OLD ,
+.Po e.g., with a suffix of
+.Pa ~ , # , .OLD , ,v ,
 or
-.Pa .orig ) ,
-ignore it.
+.Pa .orig Pc .
 .It
-If
 .Ar file
-is not executable, ignore it.
-.It
-If the
-.Xr rc.conf 5
-variable
-.Va rc_fast_and_loose
-is empty,
-source
-.Ar file
-in a sub shell,
-otherwise source
-.Ar file
-into the current shell.
+is not executable.
 .El
 .It Ic run_rc_scripts Oo options Oc file ...
 Call