#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
static unsigned int napi_gen_id = NR_CPUS;
static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
-static seqcount_t devnet_rename_seq;
+static DECLARE_RWSEM(devnet_rename_sem);
static inline void dev_base_seq_inc(struct net *net)
{
* @net: network namespace
* @name: a pointer to the buffer where the name will be stored.
* @ifindex: the ifindex of the interface to get the name from.
- *
- * The use of raw_seqcount_begin() and cond_resched() before
- * retrying is required as we want to give the writers a chance
- * to complete when CONFIG_PREEMPTION is not set.
*/
int netdev_get_name(struct net *net, char *name, int ifindex)
{
struct net_device *dev;
- unsigned int seq;
+ int ret;
-retry:
- seq = raw_seqcount_begin(&devnet_rename_seq);
+ down_read(&devnet_rename_sem);
rcu_read_lock();
+
dev = dev_get_by_index_rcu(net, ifindex);
if (!dev) {
- rcu_read_unlock();
- return -ENODEV;
+ ret = -ENODEV;
+ goto out;
}
strcpy(name, dev->name);
- rcu_read_unlock();
- if (read_seqcount_retry(&devnet_rename_seq, seq)) {
- cond_resched();
- goto retry;
- }
- return 0;
+ ret = 0;
+out:
+ rcu_read_unlock();
+ up_read(&devnet_rename_sem);
+ return ret;
}
/**
likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
return -EBUSY;
- write_seqcount_begin(&devnet_rename_seq);
+ down_write(&devnet_rename_sem);
if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
- write_seqcount_end(&devnet_rename_seq);
+ up_write(&devnet_rename_sem);
return 0;
}
err = dev_get_valid_name(net, dev, newname);
if (err < 0) {
- write_seqcount_end(&devnet_rename_seq);
+ up_write(&devnet_rename_sem);
return err;
}
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;
- write_seqcount_end(&devnet_rename_seq);
+ up_write(&devnet_rename_sem);
return ret;
}
- write_seqcount_end(&devnet_rename_seq);
+ up_write(&devnet_rename_sem);
netdev_adjacent_rename_links(dev, oldname);
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
- write_seqcount_begin(&devnet_rename_seq);
+ down_write(&devnet_rename_sem);
memcpy(dev->name, oldname, IFNAMSIZ);
memcpy(oldname, newname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;