From: Stanislav Fomichev <sdf@fomichev.me>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com,
Maxime Chevallier <maxime.chevallier@bootlin.com>,
Saeed Mahameed <saeed@kernel.org>
Subject: [PATCH net-next v10 10/14] net: ethtool: try to protect all callback with netdev instance lock
Date: Wed, 5 Mar 2025 08:37:28 -0800 [thread overview]
Message-ID: <20250305163732.2766420-11-sdf@fomichev.me> (raw)
In-Reply-To: <20250305163732.2766420-1-sdf@fomichev.me>
From: Jakub Kicinski <kuba@kernel.org>
Protect all ethtool callbacks and PHY related state with the netdev
instance lock, for drivers which want / need to have their ops
instance-locked. Basically take the lock everywhere we take rtnl_lock.
It was tempting to take the lock in ethnl_ops_begin(), but turns
out we actually nest those calls (when generating notifications).
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
---
drivers/net/netdevsim/ethtool.c | 2 --
net/dsa/conduit.c | 16 +++++++++++++++-
net/ethtool/cabletest.c | 20 ++++++++++++--------
net/ethtool/cmis_fw_update.c | 7 ++++++-
net/ethtool/features.c | 6 ++++--
net/ethtool/ioctl.c | 6 ++++++
net/ethtool/module.c | 8 +++++---
net/ethtool/netlink.c | 12 ++++++++++++
net/ethtool/phy.c | 20 ++++++++++++++------
| 2 ++
net/ethtool/tsinfo.c | 9 ++++++---
11 files changed, 82 insertions(+), 26 deletions(-)
diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c
index 7ab358616e03..4d191a3293c7 100644
--- a/drivers/net/netdevsim/ethtool.c
+++ b/drivers/net/netdevsim/ethtool.c
@@ -107,10 +107,8 @@ nsim_set_channels(struct net_device *dev, struct ethtool_channels *ch)
struct netdevsim *ns = netdev_priv(dev);
int err;
- netdev_lock(dev);
err = netif_set_real_num_queues(dev, ch->combined_count,
ch->combined_count);
- netdev_unlock(dev);
if (err)
return err;
diff --git a/net/dsa/conduit.c b/net/dsa/conduit.c
index 3dfdb3cb47dc..f21bb2551bed 100644
--- a/net/dsa/conduit.c
+++ b/net/dsa/conduit.c
@@ -26,7 +26,9 @@ static int dsa_conduit_get_regs_len(struct net_device *dev)
int len;
if (ops->get_regs_len) {
+ netdev_lock_ops(dev);
len = ops->get_regs_len(dev);
+ netdev_unlock_ops(dev);
if (len < 0)
return len;
ret += len;
@@ -57,11 +59,15 @@ static void dsa_conduit_get_regs(struct net_device *dev,
int len;
if (ops->get_regs_len && ops->get_regs) {
+ netdev_lock_ops(dev);
len = ops->get_regs_len(dev);
- if (len < 0)
+ if (len < 0) {
+ netdev_unlock_ops(dev);
return;
+ }
regs->len = len;
ops->get_regs(dev, regs, data);
+ netdev_unlock_ops(dev);
data += regs->len;
}
@@ -91,8 +97,10 @@ static void dsa_conduit_get_ethtool_stats(struct net_device *dev,
int count = 0;
if (ops->get_sset_count && ops->get_ethtool_stats) {
+ netdev_lock_ops(dev);
count = ops->get_sset_count(dev, ETH_SS_STATS);
ops->get_ethtool_stats(dev, stats, data);
+ netdev_unlock_ops(dev);
}
if (ds->ops->get_ethtool_stats)
@@ -114,8 +122,10 @@ static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev,
if (count >= 0)
phy_ethtool_get_stats(dev->phydev, stats, data);
} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
+ netdev_lock_ops(dev);
count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
ops->get_ethtool_phy_stats(dev, stats, data);
+ netdev_unlock_ops(dev);
}
if (count < 0)
@@ -132,11 +142,13 @@ static int dsa_conduit_get_sset_count(struct net_device *dev, int sset)
struct dsa_switch *ds = cpu_dp->ds;
int count = 0;
+ netdev_lock_ops(dev);
if (sset == ETH_SS_PHY_STATS && dev->phydev &&
!ops->get_ethtool_phy_stats)
count = phy_ethtool_get_sset_count(dev->phydev);
else if (ops->get_sset_count)
count = ops->get_sset_count(dev, sset);
+ netdev_unlock_ops(dev);
if (count < 0)
count = 0;
@@ -163,6 +175,7 @@ static void dsa_conduit_get_strings(struct net_device *dev, uint32_t stringset,
/* We do not want to be NULL-terminated, since this is a prefix */
pfx[sizeof(pfx) - 1] = '_';
+ netdev_lock_ops(dev);
if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
!ops->get_ethtool_phy_stats) {
mcount = phy_ethtool_get_sset_count(dev->phydev);
@@ -176,6 +189,7 @@ static void dsa_conduit_get_strings(struct net_device *dev, uint32_t stringset,
mcount = 0;
ops->get_strings(dev, stringset, data);
}
+ netdev_unlock_ops(dev);
if (ds->ops->get_strings) {
ndata = data + mcount * len;
diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c
index f22051f33868..d4a79310b33f 100644
--- a/net/ethtool/cabletest.c
+++ b/net/ethtool/cabletest.c
@@ -72,23 +72,24 @@ int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info)
dev = req_info.dev;
rtnl_lock();
+ netdev_lock_ops(dev);
phydev = ethnl_req_get_phydev(&req_info,
tb[ETHTOOL_A_CABLE_TEST_HEADER],
info->extack);
if (IS_ERR_OR_NULL(phydev)) {
ret = -EOPNOTSUPP;
- goto out_rtnl;
+ goto out_unlock;
}
ops = ethtool_phy_ops;
if (!ops || !ops->start_cable_test) {
ret = -EOPNOTSUPP;
- goto out_rtnl;
+ goto out_unlock;
}
ret = ethnl_ops_begin(dev);
if (ret < 0)
- goto out_rtnl;
+ goto out_unlock;
ret = ops->start_cable_test(phydev, info->extack);
@@ -97,7 +98,8 @@ int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info)
if (!ret)
ethnl_cable_test_started(phydev, ETHTOOL_MSG_CABLE_TEST_NTF);
-out_rtnl:
+out_unlock:
+ netdev_unlock_ops(dev);
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info);
return ret;
@@ -339,23 +341,24 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
goto out_dev_put;
rtnl_lock();
+ netdev_lock_ops(dev);
phydev = ethnl_req_get_phydev(&req_info,
tb[ETHTOOL_A_CABLE_TEST_TDR_HEADER],
info->extack);
if (IS_ERR_OR_NULL(phydev)) {
ret = -EOPNOTSUPP;
- goto out_rtnl;
+ goto out_unlock;
}
ops = ethtool_phy_ops;
if (!ops || !ops->start_cable_test_tdr) {
ret = -EOPNOTSUPP;
- goto out_rtnl;
+ goto out_unlock;
}
ret = ethnl_ops_begin(dev);
if (ret < 0)
- goto out_rtnl;
+ goto out_unlock;
ret = ops->start_cable_test_tdr(phydev, info->extack, &cfg);
@@ -365,7 +368,8 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
ethnl_cable_test_started(phydev,
ETHTOOL_MSG_CABLE_TEST_TDR_NTF);
-out_rtnl:
+out_unlock:
+ netdev_unlock_ops(dev);
rtnl_unlock();
out_dev_put:
ethnl_parse_header_dev_put(&req_info);
diff --git a/net/ethtool/cmis_fw_update.c b/net/ethtool/cmis_fw_update.c
index 48aef6220f00..946830af3e7c 100644
--- a/net/ethtool/cmis_fw_update.c
+++ b/net/ethtool/cmis_fw_update.c
@@ -418,8 +418,13 @@ cmis_fw_update_commit_image(struct ethtool_cmis_cdb *cdb,
static int cmis_fw_update_reset(struct net_device *dev)
{
__u32 reset_data = ETH_RESET_PHY;
+ int ret;
- return dev->ethtool_ops->reset(dev, &reset_data);
+ netdev_lock_ops(dev);
+ ret = dev->ethtool_ops->reset(dev, &reset_data);
+ netdev_unlock_ops(dev);
+
+ return ret;
}
void
diff --git a/net/ethtool/features.c b/net/ethtool/features.c
index b6cb101d7f19..ccffd64d5a87 100644
--- a/net/ethtool/features.c
+++ b/net/ethtool/features.c
@@ -234,9 +234,10 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
dev = req_info.dev;
rtnl_lock();
+ netdev_lock_ops(dev);
ret = ethnl_ops_begin(dev);
if (ret < 0)
- goto out_rtnl;
+ goto out_unlock;
ethnl_features_to_bitmap(old_active, dev->features);
ethnl_features_to_bitmap(old_wanted, dev->wanted_features);
ret = ethnl_parse_bitset(req_wanted, req_mask, NETDEV_FEATURE_COUNT,
@@ -286,7 +287,8 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
out_ops:
ethnl_ops_complete(dev);
-out_rtnl:
+out_unlock:
+ netdev_unlock_ops(dev);
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info);
return ret;
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index e95b41f40cac..496a2774100c 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -2317,6 +2317,7 @@ static int ethtool_phys_id(struct net_device *dev, void __user *useraddr)
*/
busy = true;
netdev_hold(dev, &dev_tracker, GFP_KERNEL);
+ netdev_unlock_ops(dev);
rtnl_unlock();
if (rc == 0) {
@@ -2331,8 +2332,10 @@ static int ethtool_phys_id(struct net_device *dev, void __user *useraddr)
do {
rtnl_lock();
+ netdev_lock_ops(dev);
rc = ops->set_phys_id(dev,
(i++ & 1) ? ETHTOOL_ID_OFF : ETHTOOL_ID_ON);
+ netdev_unlock_ops(dev);
rtnl_unlock();
if (rc)
break;
@@ -2341,6 +2344,7 @@ static int ethtool_phys_id(struct net_device *dev, void __user *useraddr)
}
rtnl_lock();
+ netdev_lock_ops(dev);
netdev_put(dev, &dev_tracker);
busy = false;
@@ -3140,6 +3144,7 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
return -EPERM;
}
+ netdev_lock_ops(dev);
if (dev->dev.parent)
pm_runtime_get_sync(dev->dev.parent);
@@ -3373,6 +3378,7 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
out:
if (dev->dev.parent)
pm_runtime_put(dev->dev.parent);
+ netdev_unlock_ops(dev);
return rc;
}
diff --git a/net/ethtool/module.c b/net/ethtool/module.c
index 6988e07bdcd6..d3d2e135e45e 100644
--- a/net/ethtool/module.c
+++ b/net/ethtool/module.c
@@ -419,19 +419,21 @@ int ethnl_act_module_fw_flash(struct sk_buff *skb, struct genl_info *info)
dev = req_info.dev;
rtnl_lock();
+ netdev_lock_ops(dev);
ret = ethnl_ops_begin(dev);
if (ret < 0)
- goto out_rtnl;
+ goto out_unlock;
ret = ethnl_module_fw_flash_validate(dev, info->extack);
if (ret < 0)
- goto out_rtnl;
+ goto out_unlock;
ret = module_flash_fw(dev, tb, skb, info);
ethnl_ops_complete(dev);
-out_rtnl:
+out_unlock:
+ netdev_unlock_ops(dev);
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info);
return ret;
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index b4c45207fa32..dee36f5cc228 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -90,6 +90,8 @@ int ethnl_ops_begin(struct net_device *dev)
if (dev->dev.parent)
pm_runtime_get_sync(dev->dev.parent);
+ netdev_ops_assert_locked(dev);
+
if (!netif_device_present(dev) ||
dev->reg_state >= NETREG_UNREGISTERING) {
ret = -ENODEV;
@@ -490,7 +492,11 @@ static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info)
ethnl_init_reply_data(reply_data, ops, req_info->dev);
rtnl_lock();
+ if (req_info->dev)
+ netdev_lock_ops(req_info->dev);
ret = ops->prepare_data(req_info, reply_data, info);
+ if (req_info->dev)
+ netdev_unlock_ops(req_info->dev);
rtnl_unlock();
if (ret < 0)
goto err_cleanup;
@@ -548,7 +554,9 @@ static int ethnl_default_dump_one(struct sk_buff *skb, struct net_device *dev,
ethnl_init_reply_data(ctx->reply_data, ctx->ops, dev);
rtnl_lock();
+ netdev_lock_ops(ctx->req_info->dev);
ret = ctx->ops->prepare_data(ctx->req_info, ctx->reply_data, info);
+ netdev_unlock_ops(ctx->req_info->dev);
rtnl_unlock();
if (ret < 0)
goto out;
@@ -693,6 +701,7 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)
dev = req_info.dev;
rtnl_lock();
+ netdev_lock_ops(dev);
dev->cfg_pending = kmemdup(dev->cfg, sizeof(*dev->cfg),
GFP_KERNEL_ACCOUNT);
if (!dev->cfg_pending) {
@@ -720,6 +729,7 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info)
kfree(dev->cfg_pending);
out_tie_cfg:
dev->cfg_pending = dev->cfg;
+ netdev_unlock_ops(dev);
rtnl_unlock();
out_dev:
ethnl_parse_header_dev_put(&req_info);
@@ -777,6 +787,8 @@ static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
req_info->dev = dev;
req_info->flags |= ETHTOOL_FLAG_COMPACT_BITSETS;
+ netdev_ops_assert_locked(dev);
+
ethnl_init_reply_data(reply_data, ops, dev);
ret = ops->prepare_data(req_info, reply_data, &info);
if (ret < 0)
diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
index ed8f690f6bac..2b428bc80c9b 100644
--- a/net/ethtool/phy.c
+++ b/net/ethtool/phy.c
@@ -158,18 +158,19 @@ int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
return ret;
rtnl_lock();
+ netdev_lock_ops(req_info.base.dev);
ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
if (ret < 0)
- goto err_unlock_rtnl;
+ goto err_unlock;
/* No PHY, return early */
if (!req_info.pdn)
- goto err_unlock_rtnl;
+ goto err_unlock;
ret = ethnl_phy_reply_size(&req_info.base, info->extack);
if (ret < 0)
- goto err_unlock_rtnl;
+ goto err_unlock;
reply_len = ret + ethnl_reply_header_size();
rskb = ethnl_reply_init(reply_len, req_info.base.dev,
@@ -178,13 +179,14 @@ int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
info, &reply_payload);
if (!rskb) {
ret = -ENOMEM;
- goto err_unlock_rtnl;
+ goto err_unlock;
}
ret = ethnl_phy_fill_reply(&req_info.base, rskb);
if (ret)
goto err_free_msg;
+ netdev_unlock_ops(req_info.base.dev);
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info.base);
genlmsg_end(rskb, reply_payload);
@@ -193,7 +195,8 @@ int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
err_free_msg:
nlmsg_free(rskb);
-err_unlock_rtnl:
+err_unlock:
+ netdev_unlock_ops(req_info.base.dev);
rtnl_unlock();
ethnl_parse_header_dev_put(&req_info.base);
return ret;
@@ -290,10 +293,15 @@ int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
rtnl_lock();
if (ctx->phy_req_info->base.dev) {
- ret = ethnl_phy_dump_one_dev(skb, ctx->phy_req_info->base.dev, cb);
+ dev = ctx->phy_req_info->base.dev;
+ netdev_lock_ops(dev);
+ ret = ethnl_phy_dump_one_dev(skb, dev, cb);
+ netdev_unlock_ops(dev);
} else {
for_each_netdev_dump(net, dev, ctx->ifindex) {
+ netdev_lock_ops(dev);
ret = ethnl_phy_dump_one_dev(skb, dev, cb);
+ netdev_unlock_ops(dev);
if (ret)
break;
--git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 58df9ad02ce8..ec41d1d7eefe 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -345,7 +345,9 @@ int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
if (ctx->match_ifindex && ctx->match_ifindex != ctx->ifindex)
break;
+ netdev_lock_ops(dev);
ret = rss_dump_one_dev(skb, cb, dev);
+ netdev_unlock_ops(dev);
if (ret)
break;
}
diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c
index 691be6c445b3..73b6a89b8731 100644
--- a/net/ethtool/tsinfo.c
+++ b/net/ethtool/tsinfo.c
@@ -448,12 +448,15 @@ int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
rtnl_lock();
if (ctx->req_info->base.dev) {
- ret = ethnl_tsinfo_dump_one_net_topo(skb,
- ctx->req_info->base.dev,
- cb);
+ dev = ctx->req_info->base.dev;
+ netdev_lock_ops(dev);
+ ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb);
+ netdev_unlock_ops(dev);
} else {
for_each_netdev_dump(net, dev, ctx->pos_ifindex) {
+ netdev_lock_ops(dev);
ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb);
+ netdev_unlock_ops(dev);
if (ret < 0 && ret != -EOPNOTSUPP)
break;
ctx->pos_phyindex = 0;
--
2.48.1
next prev parent reply other threads:[~2025-03-05 16:37 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-05 16:37 [PATCH net-next v10 00/14] net: Hold netdev instance lock during ndo operations Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 01/14] net: hold netdev instance lock during ndo_open/ndo_stop Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 02/14] net: hold netdev instance lock during nft ndo_setup_tc Stanislav Fomichev
2025-03-07 19:39 ` Eric Dumazet
2025-03-07 19:57 ` Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 03/14] net: sched: wrap doit/dumpit methods Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 04/14] net: hold netdev instance lock during qdisc ndo_setup_tc Stanislav Fomichev
2025-03-13 8:51 ` Eric Dumazet
2025-03-13 9:11 ` Stanislav Fomichev
2025-05-05 13:41 ` Cosmin Ratiu
2025-05-05 15:07 ` Stanislav Fomichev
2025-05-05 15:12 ` Cosmin Ratiu
2025-05-05 18:35 ` Jakub Kicinski
2025-05-05 18:54 ` Stanislav Fomichev
2025-05-05 19:03 ` Jakub Kicinski
2025-03-05 16:37 ` [PATCH net-next v10 05/14] net: hold netdev instance lock during queue operations Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 06/14] net: hold netdev instance lock during rtnetlink operations Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 07/14] net: hold netdev instance lock during ioctl operations Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 08/14] net: hold netdev instance lock during sysfs operations Stanislav Fomichev
2025-03-24 15:34 ` Cosmin Ratiu
2025-03-24 15:56 ` Cosmin Ratiu
2025-03-24 16:06 ` Stanislav Fomichev
2025-03-24 17:06 ` Cosmin Ratiu
2025-03-24 18:18 ` Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 09/14] net: hold netdev instance lock during ndo_bpf Stanislav Fomichev
2025-03-05 16:37 ` Stanislav Fomichev [this message]
2025-03-05 16:37 ` [PATCH net-next v10 11/14] net: replace dev_addr_sem with netdev instance lock Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 12/14] net: add option to request " Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 13/14] docs: net: document new locking reality Stanislav Fomichev
2025-03-05 16:37 ` [PATCH net-next v10 14/14] eth: bnxt: remove most dependencies on RTNL Stanislav Fomichev
2025-03-06 21:50 ` [PATCH net-next v10 00/14] net: Hold netdev instance lock during ndo operations patchwork-bot+netdevbpf
-- strict thread matches above, loose matches on Subject: below --
2025-03-02 0:08 Stanislav Fomichev
2025-03-02 0:08 ` [PATCH net-next v10 10/14] net: ethtool: try to protect all callback with netdev instance lock Stanislav Fomichev
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250305163732.2766420-11-sdf@fomichev.me \
--to=sdf@fomichev.me \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=maxime.chevallier@bootlin.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=saeed@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.