net: netprio: fix files lock and remove useless d_path bits

Add lock to prevent a race with a file closing and also remove
useless and ugly sscanf code. The extra code was never needed
and the case it supposedly protected against is in fact handled
correctly by sock_from_file as pointed out by Al Viro.

CC: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Fastabend 2012-08-14 12:34:24 +00:00 committed by David S. Miller
parent 16c0b164bd
commit f796c20cf6

View File

@ -277,12 +277,6 @@ out_free_devname:
void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
struct task_struct *p;
char *tmp = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL);
if (!tmp) {
pr_warn("Unable to attach cgrp due to alloc failure!\n");
return;
}
cgroup_taskset_for_each(p, cgrp, tset) {
unsigned int fd;
@ -296,32 +290,24 @@ void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
continue;
}
rcu_read_lock();
spin_lock(&files->file_lock);
fdt = files_fdtable(files);
for (fd = 0; fd < fdt->max_fds; fd++) {
char *path;
struct file *file;
struct socket *sock;
unsigned long s;
int rv, err = 0;
int err;
file = fcheck_files(files, fd);
if (!file)
continue;
path = d_path(&file->f_path, tmp, PAGE_SIZE);
rv = sscanf(path, "socket:[%lu]", &s);
if (rv <= 0)
continue;
sock = sock_from_file(file, &err);
if (!err)
if (sock)
sock_update_netprioidx(sock->sk, p);
}
rcu_read_unlock();
spin_unlock(&files->file_lock);
task_unlock(p);
}
kfree(tmp);
}
static struct cftype ss_files[] = {