Message ID | 1243585181-2997-1-git-send-email-gerard.lledo@gmail.com |
---|---|
State | New, archived |
Headers | show |
On Fri, 29 May 2009 11:19:41 +0300 Gerard Lledo <gerard.lledo@gmail.com> wrote: > kernel_thread() is being depracated. This patch moves the jffs2 garbage > collecting thread to the new kthread API with the minimal impact. > > Signed-off-by: Gerard Lledo <gerard.lledo@gmail.com> > --- > fs/jffs2/background.c | 22 ++++++++++++++-------- > 1 files changed, 14 insertions(+), 8 deletions(-) > > diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c > index e958010..077fa65 100644 > --- a/fs/jffs2/background.c > +++ b/fs/jffs2/background.c > @@ -15,6 +15,7 @@ > #include <linux/completion.h> > #include <linux/sched.h> > #include <linux/freezer.h> > +#include <linux/kthread.h> > #include "nodelist.h" > > > @@ -31,7 +32,7 @@ void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) > /* This must only ever be called when no GC thread is currently running */ > int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > { > - pid_t pid; > + struct task_struct *tsk; > int ret = 0; > > BUG_ON(c->gc_task); > @@ -39,15 +40,16 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > init_completion(&c->gc_thread_start); > init_completion(&c->gc_thread_exit); > > - pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES); > - if (pid < 0) { > - printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid); > + tsk = kthread_create(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index); > + if (IS_ERR(tsk)) { > + printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk)); > complete(&c->gc_thread_exit); > - ret = pid; > + ret = PTR_ERR(tsk); > } else { > - /* Wait for it... */ > - D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid)); > + D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid)); > + wake_up_process(tsk); > wait_for_completion(&c->gc_thread_start); > + ret = tsk->pid; > } A simple kthread_run() would be preferable here. The code presently sort-of open-codes it. > return ret; Also, manipulating kernel threads via their pids is atypical and inefficient. In-kernel it is better to refer to threads via their task_struct*. Fortunately all callers of this function ignore its return value so I expect we can simply change it to be void-returning. But that's a cleanup which would best be done in a spearate patch. > @@ -71,7 +73,6 @@ static int jffs2_garbage_collect_thread(void *_c) > { > struct jffs2_sb_info *c = _c; > > - daemonize("jffs2_gcd_mtd%d", c->mtd->index); > allow_signal(SIGKILL); > allow_signal(SIGSTOP); > allow_signal(SIGCONT); > @@ -107,6 +108,11 @@ static int jffs2_garbage_collect_thread(void *_c) > * the GC thread get there first. */ > schedule_timeout_interruptible(msecs_to_jiffies(50)); > > + if (kthread_should_stop()) { > + D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): kthread_stop() called.\n")); > + goto die; > + } > + > /* Put_super will send a SIGKILL and then wait on the sem. > */ > while (signal_pending(current) || freezing(current)) {
On Mon, Jun 01, 2009 at 04:20:10PM -0700, Andrew Morton wrote: > On Fri, 29 May 2009 11:19:41 +0300 > Gerard Lledo <gerard.lledo@gmail.com> wrote: > > > kernel_thread() is being depracated. This patch moves the jffs2 garbage > > collecting thread to the new kthread API with the minimal impact. > > > > Signed-off-by: Gerard Lledo <gerard.lledo@gmail.com> > > --- > > fs/jffs2/background.c | 22 ++++++++++++++-------- > > 1 files changed, 14 insertions(+), 8 deletions(-) > > > > diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c > > index e958010..077fa65 100644 > > --- a/fs/jffs2/background.c > > +++ b/fs/jffs2/background.c > > @@ -15,6 +15,7 @@ > > #include <linux/completion.h> > > #include <linux/sched.h> > > #include <linux/freezer.h> > > +#include <linux/kthread.h> > > #include "nodelist.h" > > > > > > @@ -31,7 +32,7 @@ void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) > > /* This must only ever be called when no GC thread is currently running */ > > int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > > { > > - pid_t pid; > > + struct task_struct *tsk; > > int ret = 0; > > > > BUG_ON(c->gc_task); > > @@ -39,15 +40,16 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > > init_completion(&c->gc_thread_start); > > init_completion(&c->gc_thread_exit); > > > > - pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES); > > - if (pid < 0) { > > - printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid); > > + tsk = kthread_create(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index); > > + if (IS_ERR(tsk)) { > > + printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk)); > > complete(&c->gc_thread_exit); > > - ret = pid; > > + ret = PTR_ERR(tsk); > > } else { > > - /* Wait for it... */ > > - D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid)); > > + D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid)); > > + wake_up_process(tsk); > > wait_for_completion(&c->gc_thread_start); > > + ret = tsk->pid; > > } > > A simple kthread_run() would be preferable here. The code presently > sort-of open-codes it. > > > return ret; > > Also, manipulating kernel threads via their pids is atypical and > inefficient. In-kernel it is better to refer to threads via their > task_struct*. > > Fortunately all callers of this function ignore its return value so I > expect we can simply change it to be void-returning. But that's a > cleanup which would best be done in a spearate patch. > OK, I'll redo the previous patch with kthread_run() instead. I will also post a different patch to cleanup the return value and use void.
diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c index e958010..077fa65 100644 --- a/fs/jffs2/background.c +++ b/fs/jffs2/background.c @@ -15,6 +15,7 @@ #include <linux/completion.h> #include <linux/sched.h> #include <linux/freezer.h> +#include <linux/kthread.h> #include "nodelist.h" @@ -31,7 +32,7 @@ void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) /* This must only ever be called when no GC thread is currently running */ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) { - pid_t pid; + struct task_struct *tsk; int ret = 0; BUG_ON(c->gc_task); @@ -39,15 +40,16 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) init_completion(&c->gc_thread_start); init_completion(&c->gc_thread_exit); - pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES); - if (pid < 0) { - printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid); + tsk = kthread_create(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index); + if (IS_ERR(tsk)) { + printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk)); complete(&c->gc_thread_exit); - ret = pid; + ret = PTR_ERR(tsk); } else { - /* Wait for it... */ - D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid)); + D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid)); + wake_up_process(tsk); wait_for_completion(&c->gc_thread_start); + ret = tsk->pid; } return ret; @@ -71,7 +73,6 @@ static int jffs2_garbage_collect_thread(void *_c) { struct jffs2_sb_info *c = _c; - daemonize("jffs2_gcd_mtd%d", c->mtd->index); allow_signal(SIGKILL); allow_signal(SIGSTOP); allow_signal(SIGCONT); @@ -107,6 +108,11 @@ static int jffs2_garbage_collect_thread(void *_c) * the GC thread get there first. */ schedule_timeout_interruptible(msecs_to_jiffies(50)); + if (kthread_should_stop()) { + D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): kthread_stop() called.\n")); + goto die; + } + /* Put_super will send a SIGKILL and then wait on the sem. */ while (signal_pending(current) || freezing(current)) {
kernel_thread() is being depracated. This patch moves the jffs2 garbage collecting thread to the new kthread API with the minimal impact. Signed-off-by: Gerard Lledo <gerard.lledo@gmail.com> --- fs/jffs2/background.c | 22 ++++++++++++++-------- 1 files changed, 14 insertions(+), 8 deletions(-)