[Devel] Re: [PATCH 2/2] Replace pid_t in autofs with struct pid reference
Serge E. Hallyn
serue at us.ibm.com
Tue Mar 20 14:41:25 PDT 2007
Quoting Eric W. Biederman (ebiederm at xmission.com):
> "Serge E. Hallyn" <serue at us.ibm.com> writes:
>
> > So how about the following on top of the patch Cedric sent out?
> >
> > Subject: [PATCH] autofs4: store struct pids in autofs_waitqs
> > From: Serge Hallyn <serue at us.ibm.com>
> > Date: 1174412305 -0500
> >
> > Store struct pids in autofs_waitqs in place of pidnrs to prevent
> > pid overflow problems.
>
> At first skip it doesn't looks ok.
>
> > Signed-off-by: Serge E. Hallyn <serue at us.ibm.com>
> >
> > ---
> >
> > fs/autofs4/autofs_i.h | 13 +++++++++++--
> > fs/autofs4/waitq.c | 15 ++++++++-------
> > 2 files changed, 19 insertions(+), 9 deletions(-)
> >
> > 86a5866c7672b88d48380504977496d5637642ab
> > diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
> > index 3ccec0a..5d119e3 100644
> > --- a/fs/autofs4/autofs_i.h
> > +++ b/fs/autofs4/autofs_i.h
> > @@ -79,8 +79,8 @@ struct autofs_wait_queue {
> > u64 ino;
> > uid_t uid;
> > gid_t gid;
> > - pid_t pid;
> > - pid_t tgid;
> > + struct pid *pid;
> > + struct pid *tgid;
> > /* This is for status reporting upon return */
> > int status;
> > atomic_t wait_ctr;
> > @@ -228,5 +228,14 @@ out:
> > return ret;
> > }
> >
> > +static void autofs_free_wait_queue(struct autofs_wait_queue *wq)
> > +{
> > + if (wq->pid)
> > + put_pid(wq->pid);
> > + if (wq->tgid)
> > + put_pid(wq->tgid);
> > + kfree(wq);
> > +}
> > +
> > void autofs4_dentry_release(struct dentry *);
> > extern void autofs4_kill_sb(struct super_block *);
> > diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
> > index 9857543..4a9ad9b 100644
> > --- a/fs/autofs4/waitq.c
> > +++ b/fs/autofs4/waitq.c
> > @@ -141,8 +141,8 @@ static void autofs4_notify_daemon(struct
> > packet->ino = wq->ino;
> > packet->uid = wq->uid;
> > packet->gid = wq->gid;
> > - packet->pid = wq->pid;
> > - packet->tgid = wq->tgid;
> > + packet->pid = pid_nr(wq->pid);
> > + packet->tgid = pid_nr(wq->tgid);
> > break;
>
> I'm assuming we build the packet in the process context of the
> daemon we are sending it to. If not we have a problem here.
Yes this is data being sent to a userspace daemon (Ian pls correct me if
I'm wrong) so the pid_nr is the only thing we can send.
> > }
> > default:
> > @@ -292,8 +292,8 @@ int autofs4_wait(struct autofs_sb_info *
> > wq->ino = autofs4_get_ino(sbi);
> > wq->uid = current->uid;
> > wq->gid = current->gid;
> > - wq->pid = pid_nr(task_pid(current));
> > - wq->tgid = pid_nr(task_tgid(current));
> > + wq->pid = get_pid(task_pid(current));
> > + wq->tgid = get_pid(task_tgid(current));
> > wq->status = -EINTR; /* Status return if interrupted */
> > atomic_set(&wq->wait_ctr, 2);
> > mutex_unlock(&sbi->wq_mutex);
> > @@ -360,8 +360,9 @@ int autofs4_wait(struct autofs_sb_info *
> > status = wq->status;
> >
> > /* Are we the last process to need status? */
> > - if (atomic_dec_and_test(&wq->wait_ctr))
> > - kfree(wq);
> > + if (atomic_dec_and_test(&wq->wait_ctr)) {
> > + autofs_free_wait_queue(wq);
> > + }
>
> Unnecessary braces....
Thanks. Also needed another tweak in the .h file. Here's a new patch.
Ian, please let me know if this (combined with the previous patch from
Cedric) is acceptable to you.
thanks,
-serge
Subject: [PATCH] autofs4: store struct pids in autofs_waitqs
From: Serge Hallyn <serue at us.ibm.com>
Date: 1174412305 -0500
Store struct pids in autofs_waitqs in place of pidnrs to prevent
pid overflow problems.
Signed-off-by: Serge E. Hallyn <serue at us.ibm.com>
---
fs/autofs4/autofs_i.h | 13 +++++++++++--
fs/autofs4/waitq.c | 12 ++++++------
2 files changed, 17 insertions(+), 8 deletions(-)
03944aae0b9cb4a36d091f275d2f2217447b27ec
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 3ccec0a..8260743 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -79,8 +79,8 @@ struct autofs_wait_queue {
u64 ino;
uid_t uid;
gid_t gid;
- pid_t pid;
- pid_t tgid;
+ struct pid *pid;
+ struct pid *tgid;
/* This is for status reporting upon return */
int status;
atomic_t wait_ctr;
@@ -228,5 +228,14 @@ out:
return ret;
}
+static inline void autofs_free_wait_queue(struct autofs_wait_queue *wq)
+{
+ if (wq->pid)
+ put_pid(wq->pid);
+ if (wq->tgid)
+ put_pid(wq->tgid);
+ kfree(wq);
+}
+
void autofs4_dentry_release(struct dentry *);
extern void autofs4_kill_sb(struct super_block *);
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 9857543..6c696ea 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -141,8 +141,8 @@ static void autofs4_notify_daemon(struct
packet->ino = wq->ino;
packet->uid = wq->uid;
packet->gid = wq->gid;
- packet->pid = wq->pid;
- packet->tgid = wq->tgid;
+ packet->pid = pid_nr(wq->pid);
+ packet->tgid = pid_nr(wq->tgid);
break;
}
default:
@@ -292,8 +292,8 @@ int autofs4_wait(struct autofs_sb_info *
wq->ino = autofs4_get_ino(sbi);
wq->uid = current->uid;
wq->gid = current->gid;
- wq->pid = pid_nr(task_pid(current));
- wq->tgid = pid_nr(task_tgid(current));
+ wq->pid = get_pid(task_pid(current));
+ wq->tgid = get_pid(task_tgid(current));
wq->status = -EINTR; /* Status return if interrupted */
atomic_set(&wq->wait_ctr, 2);
mutex_unlock(&sbi->wq_mutex);
@@ -361,7 +361,7 @@ int autofs4_wait(struct autofs_sb_info *
/* Are we the last process to need status? */
if (atomic_dec_and_test(&wq->wait_ctr))
- kfree(wq);
+ autofs_free_wait_queue(wq);
return status;
}
@@ -390,7 +390,7 @@ int autofs4_wait_release(struct autofs_s
wq->status = status;
if (atomic_dec_and_test(&wq->wait_ctr)) /* Is anyone still waiting for this guy? */
- kfree(wq);
+ autofs_free_wait_queue(wq);
else
wake_up_interruptible(&wq->queue);
--
1.1.6
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