On Fri, 2017-11-10 at 12:47 +1100, NeilBrown wrote:
> On Wed, Nov 08 2017, Joshua Watt wrote:
>
> > The "kill" client entry in debugfs can be used to kill client
> > tasks.
> > Writing "0" causes only the currently pending tasks to be killed,
> > while
> > writing "1" all currently pending, and any future pending tasks to
> > be
> > killed.
> >
> > Signed-off-by: Joshua Watt <JPEWhacker@xxxxxxxxx>
> > ---
> > net/sunrpc/debugfs.c | 48
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 48 insertions(+)
> >
> > diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c
> > index e980d2a493de..a2f33d168873 100644
> > --- a/net/sunrpc/debugfs.c
> > +++ b/net/sunrpc/debugfs.c
> > @@ -118,6 +118,50 @@ static const struct file_operations tasks_fops
> > = {
> > .release = tasks_release,
> > };
> >
> > +static int
> > +kill_set(void *data, u64 val)
> > +{
> > + struct rpc_clnt *clnt = data;
> > +
> > + rpc_killall_tasks(clnt, (int)val);
> > + return 0;
> > +}
> > +
> > +static int
> > +kill_open(struct inode *inode, struct file *filp)
> > +{
> > + int ret = simple_attr_open(inode, filp, NULL, kill_set,
> > "%i");
> > +
> > + if (!ret) {
> > + struct rpc_clnt *clnt = inode->i_private;
> > +
> > + if (!atomic_inc_not_zero(&clnt->cl_count)) {
> > + simple_attr_release(inode, filp);
> > + ret = -EINVAL;
> > + }
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int
> > +kill_release(struct inode *inode, struct file *filp)
> > +{
> > + struct rpc_clnt *clnt = inode->i_private;
> > +
> > + rpc_release_client(clnt);
> > +
> > + return simple_attr_release(inode, filp);
> > +}
> > +
> > +static const struct file_operations kill_fops = {
> > + .owner = THIS_MODULE,
> > + .open = kill_open,
> > + .release = kill_release,
> > + .write = debugfs_attr_write,
> > + .llseek = no_llseek,
> > +};
> > +
> > void
> > rpc_clnt_debugfs_register(struct rpc_clnt *clnt)
> > {
> > @@ -160,6 +204,10 @@ rpc_clnt_debugfs_register(struct rpc_clnt
> > *clnt)
> > if (!debugfs_create_symlink("xprt", clnt->cl_debugfs,
> > name))
> > goto out_err;
> >
> > + if (!debugfs_create_file("kill", S_IFREG | 0200, clnt-
> > >cl_debugfs,
> > + clnt, &kill_fops))
>
> S_IFREG is the default for debugfs_create_file, so it isn't needed.
> There are about 1085 calls to debugfs_create_file() in the kernel of
> which 85 specify S_IFREG. Maybe we should fix them all...
>
> And please use S_IWUSR rather than 0200.
Oddly enough, checkpatch.pl complains if you use S_IWUSR, stating that
you should use the octal instead:
WARNING: Symbolic permissions 'S_IWUSR' are not preferred. Consider
using octal permissions '0200'.
I'm alright using S_IWUSR here since the rest of the file uses them
("when in Rome" and all that).
>
> I don't know if we really need this functionality if debugfs, but I
> guess that is why we are putting it there - to see.
Yes, I purposely constructed this patch so it could be skipped if it is
unneeded/unwanted.
>
> Thanks,
> NeilBrown
>
>
> > + goto out_err;
> > +
> > return;
> > out_err:
> > debugfs_remove_recursive(clnt->cl_debugfs);
> > --
> > 2.13.6
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