From: Peter Zijlstra <peterz@infradead.org> To: rjw@rjwysocki.net, oleg@redhat.com, mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, Will Deacon <will@kernel.org> Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, tj@kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v3 2/6] freezer,umh: Clean up freezer/initrd interaction Date: Sat, 09 Oct 2021 12:07:56 +0200 [thread overview] Message-ID: <20211009101444.912374035@infradead.org> (raw) In-Reply-To: <20211009100754.690769957@infradead.org> handle_initrd() marks itself as PF_FREEZER_SKIP in order to ensure that the UMH, which is going to freeze the system, doesn't indefinitely wait for it's caller. Rework things by adding UMH_FREEZABLE to indicate the completion is freezable. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- include/linux/umh.h | 9 +++++---- init/do_mounts_initrd.c | 10 +--------- kernel/umh.c | 8 ++++++++ 3 files changed, 14 insertions(+), 13 deletions(-) --- a/include/linux/umh.h +++ b/include/linux/umh.h @@ -11,10 +11,11 @@ struct cred; struct file; -#define UMH_NO_WAIT 0 /* don't wait at all */ -#define UMH_WAIT_EXEC 1 /* wait for the exec, but not the process */ -#define UMH_WAIT_PROC 2 /* wait for the process to complete */ -#define UMH_KILLABLE 4 /* wait for EXEC/PROC killable */ +#define UMH_NO_WAIT 0x00 /* don't wait at all */ +#define UMH_WAIT_EXEC 0x01 /* wait for the exec, but not the process */ +#define UMH_WAIT_PROC 0x02 /* wait for the process to complete */ +#define UMH_KILLABLE 0x04 /* wait for EXEC/PROC killable */ +#define UMH_FREEZABLE 0x08 /* wait for EXEC/PROC freezable */ struct subprocess_info { struct work_struct work; --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -79,19 +79,11 @@ static void __init handle_initrd(void) init_mkdir("/old", 0700); init_chdir("/old"); - /* - * In case that a resume from disk is carried out by linuxrc or one of - * its children, we need to tell the freezer not to wait for us. - */ - current->flags |= PF_FREEZER_SKIP; - info = call_usermodehelper_setup("/linuxrc", argv, envp_init, GFP_KERNEL, init_linuxrc, NULL, NULL); if (!info) return; - call_usermodehelper_exec(info, UMH_WAIT_PROC); - - current->flags &= ~PF_FREEZER_SKIP; + call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE); /* move initrd to rootfs' /old */ init_mount("..", ".", NULL, MS_MOVE, NULL); --- a/kernel/umh.c +++ b/kernel/umh.c @@ -28,6 +28,7 @@ #include <linux/async.h> #include <linux/uaccess.h> #include <linux/initrd.h> +#include <linux/freezer.h> #include <trace/events/module.h> @@ -436,6 +437,9 @@ int call_usermodehelper_exec(struct subp if (wait == UMH_NO_WAIT) /* task has freed sub_info */ goto unlock; + if (wait & UMH_FREEZABLE) + freezer_do_not_count(); + if (wait & UMH_KILLABLE) { retval = wait_for_completion_killable(&done); if (!retval) @@ -448,6 +452,10 @@ int call_usermodehelper_exec(struct subp } wait_for_completion(&done); + + if (wait & UMH_FREEZABLE) + freezer_count(); + wait_done: retval = sub_info->retval; out:
next prev parent reply other threads:[~2021-10-09 10:19 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-09 10:07 [PATCH v3 0/6] Freezer rewrite Peter Zijlstra 2021-10-09 10:07 ` [PATCH v3 1/6] freezer: Have {,un}lock_system_sleep() save/restore flags Peter Zijlstra 2021-10-14 8:58 ` Will Deacon 2021-10-09 10:07 ` Peter Zijlstra [this message] 2021-10-14 9:13 ` [PATCH v3 2/6] freezer,umh: Clean up freezer/initrd interaction Will Deacon 2021-10-09 10:07 ` [PATCH v3 3/6] ptrace: Order and comment PT_flags Peter Zijlstra 2021-10-14 9:31 ` Will Deacon 2021-10-14 14:27 ` Peter Zijlstra 2021-10-09 10:07 ` [PATCH v3 4/6] ptrace: Track __TASK_TRACED state in p->ptrace Peter Zijlstra 2021-10-09 10:07 ` [PATCH v3 5/6] sched,ptrace: Avoid relying on __TASK_TRACED | __TASK_STOPPED Peter Zijlstra 2021-10-09 10:08 ` [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic Peter Zijlstra 2021-10-18 13:36 ` Peter Zijlstra
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