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Message-ID: <20101108203258.22479.3417.stgit@crlf.mtv.corp.google.com>
Date: Mon, 08 Nov 2010 12:32:59 -0800
From: Mike Waychison <mikew@...gle.com>
To: simon.kagstrom@...insight.net, davem@...emloft.net,
nhorman@...driver.com, Matt Mackall <mpm@...enic.com>
Cc: adurbin@...gle.com, linux-kernel@...r.kernel.org,
chavey@...gle.com, Greg KH <greg@...ah.com>,
Américo Wang <xiyou.wangcong@...il.com>,
akpm@...ux-foundation.org, linux-api@...r.kernel.org
Subject: [PATCH v2 14/23] netpoll: Move target code into netpoll_targets.c
Move all the target handling code out of netconsole.c and into a new
file, net/core/netpoll_targets.c.
In doing so, we have to remove the __exit and __init attributes on the
constructors/desctructors, as well as export the needed symbols to
modules. Reference counting also becomes a no-op when dynamic targets
are disabled (!CONFIG_NETPOLL_TARGETS_DYNAMIC).
>>From netpoll_targets.c's perspective, MAX_PARAM_LENGTH isn't available,
so we ensure that the string being passed in is zero-terminated and do
an open strlen() instead of strnlen().
Signed-off-by: Mike Waychison <mikew@...gle.com>
---
drivers/net/netconsole.c | 820 ---------------------------------------
include/linux/netpoll_targets.h | 76 ++++
net/core/Makefile | 1
net/core/netpoll_targets.c | 746 +++++++++++++++++++++++++++++++++++
4 files changed, 825 insertions(+), 818 deletions(-)
create mode 100644 include/linux/netpoll_targets.h
create mode 100644 net/core/netpoll_targets.c
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 0d77fc8..64b0e4f 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -37,13 +37,11 @@
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/module.h>
-#include <linux/slab.h>
#include <linux/console.h>
#include <linux/moduleparam.h>
-#include <linux/string.h>
#include <linux/netpoll.h>
+#include <linux/netpoll_targets.h>
#include <linux/inet.h>
-#include <linux/configfs.h>
MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@...enic.com>");
MODULE_DESCRIPTION("Console driver for network interfaces");
@@ -65,743 +63,8 @@ static int __init option_setup(char *opt)
__setup("netconsole=", option_setup);
#endif /* MODULE */
-struct netpoll_targets {
- struct list_head list;
- spinlock_t lock;
- u16 default_local_port, default_remote_port;
-#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
- struct configfs_subsystem configfs_subsys;
-#endif
- struct notifier_block netdev_notifier;
- char *subsys_name;
-};
-#define DEFINE_NETPOLL_TARGETS(x) struct netpoll_targets x = \
- { .list = LIST_HEAD_INIT(x.list), \
- .lock = __SPIN_LOCK_UNLOCKED(x.lock) }
static DEFINE_NETPOLL_TARGETS(targets);
-#define NETPOLL_DISABLED 0
-#define NETPOLL_SETTINGUP 1
-#define NETPOLL_ENABLED 2
-#define NETPOLL_CLEANING 3
-
-/**
- * struct netpoll_target - Represents a configured netpoll target.
- * @list: Links this target into the netpoll_targets.list.
- * @item: Links us into the configfs subsystem hierarchy.
- * @np_state: Enabled / Disabled / SettingUp / Cleaning
- * Visible from userspace (read-write) as "enabled".
- * We maintain a state machine here of the valid states. Either a
- * target is enabled or disabled, but it may also be in a
- * transitional state whereby nobody is allowed to act on the
- * target other than whoever owns the transition.
- *
- * Also, other parameters of a target may be modified at
- * runtime only when it is disabled (np_state == NETPOLL_ENABLED).
- * @np: The netpoll structure for this target.
- * Contains the other userspace visible parameters:
- * dev_name (read-write)
- * local_port (read-write)
- * remote_port (read-write)
- * local_ip (read-write)
- * remote_ip (read-write)
- * local_mac (read-only)
- * remote_mac (read-write)
- */
-struct netpoll_target {
- struct netpoll_targets *nts;
- struct list_head list;
-#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
- struct config_item item;
-#endif
- int np_state;
- struct netpoll np;
- struct work_struct cleanup_work;
-};
-
-static void netpoll_target_get(struct netpoll_target *nt);
-static void netpoll_target_put(struct netpoll_target *nt);
-
-static void deferred_netpoll_cleanup(struct work_struct *work)
-{
- struct netpoll_target *nt;
- struct netpoll_targets *nts;
- unsigned long flags;
-
- nt = container_of(work, struct netpoll_target, cleanup_work);
- nts = nt->nts;
-
- netpoll_cleanup(&nt->np);
-
- spin_lock_irqsave(&nts->lock, flags);
- BUG_ON(nt->np_state != NETPOLL_CLEANING);
- nt->np_state = NETPOLL_DISABLED;
- spin_unlock_irqrestore(&nts->lock, flags);
-
- netpoll_target_put(nt);
-}
-
-/* Allocate new target (from boot/module param) and setup netpoll for it */
-static struct netpoll_target *alloc_param_target(struct netpoll_targets *nts,
- char *target_config)
-{
- int err = -ENOMEM;
- struct netpoll_target *nt;
-
- /*
- * Allocate and initialize with defaults.
- * Note that these targets get their config_item fields zeroed-out.
- */
- nt = kzalloc(sizeof(*nt), GFP_KERNEL);
- if (!nt) {
- printk(KERN_ERR "%s: failed to allocate memory\n",
- nts->subsys_name);
- goto fail;
- }
-
- nt->nts = nts;
- nt->np.name = nts->subsys_name;
- strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
- nt->np.local_port = nts->default_local_port;
- nt->np.remote_port = nts->default_remote_port;
- memset(nt->np.remote_mac, 0xff, ETH_ALEN);
- INIT_WORK(&nt->cleanup_work, deferred_netpoll_cleanup);
-
- /* Parse parameters and setup netpoll */
- err = netpoll_parse_options(&nt->np, target_config);
- if (err)
- goto fail;
-
- err = netpoll_setup(&nt->np);
- if (err)
- goto fail;
-
- nt->np_state = NETPOLL_ENABLED;
-
- return nt;
-
-fail:
- kfree(nt);
- return ERR_PTR(err);
-}
-
-/* Cleanup netpoll for given target (from boot/module param) and free it */
-static void free_param_target(struct netpoll_target *nt)
-{
- cancel_work_sync(&nt->cleanup_work);
- if (nt->np_state == NETPOLL_CLEANING || nt->np_state == NETPOLL_ENABLED)
- netpoll_cleanup(&nt->np);
- kfree(nt);
-}
-
-#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
-
-/*
- * Our subsystem hierarchy is:
- *
- * /sys/kernel/config/<subsys_name>/
- * |
- * <target>/
- * | enabled
- * | dev_name
- * | local_port
- * | remote_port
- * | local_ip
- * | remote_ip
- * | local_mac
- * | remote_mac
- * |
- * <target>/...
- */
-
-struct netpoll_target_attr {
- struct configfs_attribute attr;
- ssize_t (*show)(struct netpoll_target *nt,
- char *buf);
- ssize_t (*store)(struct netpoll_target *nt,
- const char *buf,
- size_t count);
-};
-
-static struct netpoll_target *to_target(struct config_item *item)
-{
- return item ?
- container_of(item, struct netpoll_target, item) :
- NULL;
-}
-
-/*
- * Wrapper over simple_strtol (base 10) with sanity and range checking.
- * We return (signed) long only because we may want to return errors.
- * Do not use this to convert numbers that are allowed to be negative.
- */
-static long strtol10_check_range(struct netpoll_targets *nts,
- const char *cp, long min, long max)
-{
- long ret;
- char *p = (char *) cp;
-
- WARN_ON(min < 0);
- WARN_ON(max < min);
-
- ret = simple_strtol(p, &p, 10);
-
- if (*p && (*p != '\n')) {
- printk(KERN_ERR "%s: invalid input\n", nts->subsys_name);
- return -EINVAL;
- }
- if ((ret < min) || (ret > max)) {
- printk(KERN_ERR "%s: input %ld must be between %ld and %ld\n",
- nts->subsys_name, ret, min, max);
- return -EINVAL;
- }
-
- return ret;
-}
-
-/*
- * Attribute operations for netpoll_target.
- */
-
-static ssize_t show_enabled(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%d\n",
- nt->np_state == NETPOLL_ENABLED);
-}
-
-static ssize_t show_dev_name(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
-}
-
-static ssize_t show_local_port(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
-}
-
-static ssize_t show_remote_port(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
-}
-
-static ssize_t show_local_ip(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
-}
-
-static ssize_t show_remote_ip(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
-}
-
-static ssize_t show_local_mac(struct netpoll_target *nt, char *buf)
-{
- struct net_device *dev = nt->np.dev;
- static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
-
- return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
-}
-
-static ssize_t show_remote_mac(struct netpoll_target *nt, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
-}
-
-/*
- * This one is special -- targets created through the configfs interface
- * are not enabled (and the corresponding netpoll activated) by default.
- * The user is expected to set the desired parameters first (which
- * would enable him to dynamically add new netpoll targets for new
- * network interfaces as and when they come up).
- */
-static ssize_t store_enabled(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- struct netpoll_targets *nts = nt->nts;
- unsigned long flags;
- int err;
- long enabled;
-
- enabled = strtol10_check_range(nts, buf, 0, 1);
- if (enabled < 0)
- return enabled;
-
- if (enabled) { /* 1 */
- spin_lock_irqsave(&nts->lock, flags);
- if (nt->np_state != NETPOLL_DISABLED)
- goto busy;
- else {
- nt->np_state = NETPOLL_SETTINGUP;
- /*
- * Nominally, we would grab an extra reference on the
- * config_item here for dynamic targets while we let go
- * of the lock, but this isn't required in this case
- * because there is a reference implicitly held by the
- * caller of the store operation.
- */
- spin_unlock_irqrestore(&nts->lock, flags);
- }
-
- /*
- * Skip netpoll_parse_options() -- all the attributes are
- * already configured via configfs. Just print them out.
- */
- netpoll_print_options(&nt->np);
-
- err = netpoll_setup(&nt->np);
- spin_lock_irqsave(&nts->lock, flags);
- if (err)
- nt->np_state = NETPOLL_DISABLED;
- else
- nt->np_state = NETPOLL_ENABLED;
- spin_unlock_irqrestore(&nts->lock, flags);
- if (err)
- return err;
-
- printk(KERN_INFO "%s: network logging started\n",
- nts->subsys_name);
- } else { /* 0 */
- spin_lock_irqsave(&nts->lock, flags);
- if (nt->np_state == NETPOLL_ENABLED)
- nt->np_state = NETPOLL_CLEANING;
- else if (nt->np_state != NETPOLL_DISABLED)
- goto busy;
- spin_unlock_irqrestore(&nts->lock, flags);
-
- netpoll_cleanup(&nt->np);
-
- spin_lock_irqsave(&nts->lock, flags);
- nt->np_state = NETPOLL_DISABLED;
- spin_unlock_irqrestore(&nts->lock, flags);
- }
-
- return strnlen(buf, count);
-busy:
- spin_unlock_irqrestore(&nts->lock, flags);
- return -EBUSY;
-}
-
-static ssize_t store_dev_name(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- size_t len;
-
- strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
-
- /* Get rid of possible trailing newline from echo(1) */
- len = strnlen(nt->np.dev_name, IFNAMSIZ);
- if (nt->np.dev_name[len - 1] == '\n')
- nt->np.dev_name[len - 1] = '\0';
-
- return strnlen(buf, count);
-}
-
-static ssize_t store_local_port(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- long local_port;
-#define __U16_MAX ((__u16) ~0U)
-
- local_port = strtol10_check_range(nt->nts, buf, 0, __U16_MAX);
- if (local_port < 0)
- return local_port;
-
- nt->np.local_port = local_port;
-
- return strnlen(buf, count);
-}
-
-static ssize_t store_remote_port(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- long remote_port;
-#define __U16_MAX ((__u16) ~0U)
-
- remote_port = strtol10_check_range(nt->nts, buf, 0, __U16_MAX);
- if (remote_port < 0)
- return remote_port;
-
- nt->np.remote_port = remote_port;
-
- return strnlen(buf, count);
-}
-
-static ssize_t store_local_ip(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- nt->np.local_ip = in_aton(buf);
-
- return strnlen(buf, count);
-}
-
-static ssize_t store_remote_ip(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- nt->np.remote_ip = in_aton(buf);
-
- return strnlen(buf, count);
-}
-
-static ssize_t store_remote_mac(struct netpoll_target *nt,
- const char *buf,
- size_t count)
-{
- u8 remote_mac[ETH_ALEN];
- char *p = (char *) buf;
- int i;
-
- for (i = 0; i < ETH_ALEN - 1; i++) {
- remote_mac[i] = simple_strtoul(p, &p, 16);
- if (*p != ':')
- goto invalid;
- p++;
- }
- remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
- if (*p && (*p != '\n'))
- goto invalid;
-
- memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
-
- return strnlen(buf, count);
-
-invalid:
- printk(KERN_ERR "%s: invalid input\n", nt->nts->subsys_name);
- return -EINVAL;
-}
-
-/*
- * Attribute definitions for netpoll_target.
- */
-
-#define __NETPOLL_TARGET_ATTR_RO(_name, _prefix_...) \
-static struct netpoll_target_attr netpoll_target_##_name = \
- __CONFIGFS_ATTR(_name, S_IRUGO, show_##_prefix_##_name, NULL)
-
-#define __NETPOLL_TARGET_ATTR_RW(_name, _prefix_...) \
-static struct netpoll_target_attr netpoll_target_##_name = \
- __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, \
- show_##_prefix_##_name, store_##_prefix_##_name)
-
-#define NETPOLL_WRAP_ATTR_STORE(_name) \
-static ssize_t store_locked_##_name(struct netpoll_target *nt, \
- const char *buf, \
- size_t count) \
-{ \
- struct netpoll_targets *nts = nt->nts; \
- unsigned long flags; \
- ssize_t ret; \
- spin_lock_irqsave(&nts->lock, flags); \
- if (nt->np_state != NETPOLL_DISABLED) { \
- printk(KERN_ERR "%s: target (%s) is enabled, " \
- "disable to update parameters\n", \
- nts->subsys_name, \
- config_item_name(&nt->item)); \
- spin_unlock_irqrestore(&nts->lock, flags); \
- return -EBUSY; \
- } \
- ret = store_##_name(nt, buf, count); \
- spin_unlock_irqrestore(&nts->lock, flags); \
- return ret; \
-}
-
-#define NETPOLL_WRAP_ATTR_SHOW(_name) \
-static ssize_t show_locked_##_name(struct netpoll_target *nt, char *buf) \
-{ \
- struct netpoll_targets *nts = nt->nts; \
- unsigned long flags; \
- ssize_t ret; \
- spin_lock_irqsave(&nts->lock, flags); \
- ret = show_##_name(nt, buf); \
- spin_unlock_irqrestore(&nts->lock, flags); \
- return ret; \
-}
-
-#define NETPOLL_TARGET_ATTR_RW(_name) \
- NETPOLL_WRAP_ATTR_STORE(_name) \
- NETPOLL_WRAP_ATTR_SHOW(_name) \
- __NETPOLL_TARGET_ATTR_RW(_name, locked_)
-
-#define NETPOLL_TARGET_ATTR_RO(_name) \
- NETPOLL_WRAP_ATTR_SHOW(_name) \
- __NETPOLL_TARGET_ATTR_RO(_name, locked_)
-
-__NETPOLL_TARGET_ATTR_RW(enabled);
-NETPOLL_TARGET_ATTR_RW(dev_name);
-NETPOLL_TARGET_ATTR_RW(local_port);
-NETPOLL_TARGET_ATTR_RW(remote_port);
-NETPOLL_TARGET_ATTR_RW(local_ip);
-NETPOLL_TARGET_ATTR_RW(remote_ip);
-NETPOLL_TARGET_ATTR_RO(local_mac);
-NETPOLL_TARGET_ATTR_RW(remote_mac);
-
-static struct configfs_attribute *netpoll_target_attrs[] = {
- &netpoll_target_enabled.attr,
- &netpoll_target_dev_name.attr,
- &netpoll_target_local_port.attr,
- &netpoll_target_remote_port.attr,
- &netpoll_target_local_ip.attr,
- &netpoll_target_remote_ip.attr,
- &netpoll_target_local_mac.attr,
- &netpoll_target_remote_mac.attr,
- NULL,
-};
-
-/*
- * Item operations and type for netpoll_target.
- */
-
-static void netpoll_target_release(struct config_item *item)
-{
- kfree(to_target(item));
-}
-
-static ssize_t netpoll_target_attr_show(struct config_item *item,
- struct configfs_attribute *attr,
- char *buf)
-{
- ssize_t ret = -EINVAL;
- struct netpoll_target *nt = to_target(item);
- struct netpoll_target_attr *na =
- container_of(attr, struct netpoll_target_attr, attr);
-
- if (na->show)
- ret = na->show(nt, buf);
-
- return ret;
-}
-
-static ssize_t netpoll_target_attr_store(struct config_item *item,
- struct configfs_attribute *attr,
- const char *buf,
- size_t count)
-{
- ssize_t ret = -EINVAL;
- struct netpoll_target *nt = to_target(item);
- struct netpoll_target_attr *na =
- container_of(attr, struct netpoll_target_attr, attr);
-
- if (na->store)
- ret = na->store(nt, buf, count);
-
- return ret;
-}
-
-static struct configfs_item_operations netpoll_target_item_ops = {
- .release = netpoll_target_release,
- .show_attribute = netpoll_target_attr_show,
- .store_attribute = netpoll_target_attr_store,
-};
-
-static struct config_item_type netpoll_target_type = {
- .ct_attrs = netpoll_target_attrs,
- .ct_item_ops = &netpoll_target_item_ops,
- .ct_owner = THIS_MODULE,
-};
-
-static struct netpoll_targets *group_to_targets(struct config_group *group)
-{
- struct configfs_subsystem *subsys;
- subsys = container_of(group, struct configfs_subsystem, su_group);
- return container_of(subsys, struct netpoll_targets, configfs_subsys);
-}
-
-/*
- * Group operations and type for netpoll_target_subsys.
- */
-
-static struct config_item *make_netpoll_target(struct config_group *group,
- const char *name)
-{
- struct netpoll_targets *nts = group_to_targets(group);
- struct netpoll_target *nt;
- unsigned long flags;
-
- /*
- * Allocate and initialize with defaults.
- * Target is disabled at creation (enabled == 0).
- */
- nt = kzalloc(sizeof(*nt), GFP_KERNEL);
- if (!nt) {
- printk(KERN_ERR "%s: failed to allocate memory\n",
- nts->subsys_name);
- return ERR_PTR(-ENOMEM);
- }
-
- nt->nts = nts;
- nt->np.name = nts->subsys_name;
- strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
- nt->np.local_port = nts->default_local_port;
- nt->np.remote_port = nts->default_remote_port;
- memset(nt->np.remote_mac, 0xff, ETH_ALEN);
- INIT_WORK(&nt->cleanup_work, deferred_netpoll_cleanup);
-
- /* Initialize the config_item member */
- config_item_init_type_name(&nt->item, name, &netpoll_target_type);
-
- /* Adding, but it is disabled */
- spin_lock_irqsave(&nts->lock, flags);
- list_add(&nt->list, &nts->list);
- spin_unlock_irqrestore(&nts->lock, flags);
-
- return &nt->item;
-}
-
-static void drop_netpoll_target(struct config_group *group,
- struct config_item *item)
-{
- struct netpoll_targets *nts = group_to_targets(group);
- struct netpoll_target *nt = to_target(item);
- unsigned long flags;
-
- spin_lock_irqsave(&nts->lock, flags);
- list_del(&nt->list);
- spin_unlock_irqrestore(&nts->lock, flags);
-
- /*
- * The target may have never been enabled, or was manually disabled
- * before being removed so netpoll may have already been cleaned up.
- *
- * If it queued for cleanup already, that is fine, as that path holds a
- * reference to the config_item.
- */
- if (nt->np_state == NETPOLL_ENABLED)
- netpoll_cleanup(&nt->np);
-
- netpoll_target_put(nt);
-}
-
-static struct configfs_group_operations netpoll_subsys_group_ops = {
- .make_item = make_netpoll_target,
- .drop_item = drop_netpoll_target,
-};
-
-static struct config_item_type netpoll_subsys_type = {
- .ct_group_ops = &netpoll_subsys_group_ops,
- .ct_owner = THIS_MODULE,
-};
-
-static int __init dynamic_netpoll_targets_init(const char *subsys_name,
- struct netpoll_targets *nts)
-{
- struct configfs_subsystem *subsys = &nts->configfs_subsys;
-
- config_group_init(&subsys->su_group);
- mutex_init(&subsys->su_mutex);
- strncpy((char *)&subsys->su_group.cg_item.ci_namebuf, subsys_name,
- CONFIGFS_ITEM_NAME_LEN);
- subsys->su_group.cg_item.ci_type = &netpoll_subsys_type;
- return configfs_register_subsystem(subsys);
-}
-
-static void __exit dynamic_netpoll_targets_exit(struct netpoll_targets *nts)
-{
- configfs_unregister_subsystem(&nts->configfs_subsys);
-}
-
-/*
- * Targets that were created by parsing the boot/module option string
- * do not exist in the configfs hierarchy (and have NULL names) and will
- * never go away, so make these a no-op for them.
- */
-static void netpoll_target_get(struct netpoll_target *nt)
-{
- if (config_item_name(&nt->item))
- config_item_get(&nt->item);
-}
-
-static void netpoll_target_put(struct netpoll_target *nt)
-{
- if (config_item_name(&nt->item))
- config_item_put(&nt->item);
-}
-
-#else /* !CONFIG_NETPOLL_TARGETS_DYNAMIC */
-
-static int __init dynamic_netpoll_targets_init(const char *subsys_name,
- struct netpoll_targets *nts)
-{
- return 0;
-}
-
-static void __exit dynamic_netpoll_targets_exit(struct netpoll_targets *nts)
-{
-}
-
-/*
- * No danger of targets going away from under us when dynamic
- * reconfigurability is off.
- */
-static void netpoll_target_get(struct netpoll_target *nt)
-{
-}
-
-static void netpoll_target_put(struct netpoll_target *nt)
-{
-}
-
-#endif /* CONFIG_NETPOLL_TARGETS_DYNAMIC */
-
-/*
- * Call netpoll_cleanup on this target asynchronously.
- * nts->lock is required.
- */
-static void defer_netpoll_cleanup(struct netpoll_target *nt)
-{
- if (nt->np_state != NETPOLL_ENABLED)
- return;
- netpoll_target_get(nt);
- nt->np_state = NETPOLL_CLEANING;
- schedule_work(&nt->cleanup_work);
-}
-
-/* Handle network interface device notifications */
-static int netpoll_targets_netdev_event(struct notifier_block *this,
- unsigned long event,
- void *ptr)
-{
- struct netpoll_targets *nts = container_of(this, struct netpoll_targets,
- netdev_notifier);
- unsigned long flags;
- struct netpoll_target *nt;
- struct net_device *dev = ptr;
-
- if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
- event == NETDEV_BONDING_DESLAVE))
- goto done;
-
- spin_lock_irqsave(&nts->lock, flags);
- list_for_each_entry(nt, &nts->list, list) {
- if (nt->np_state == NETPOLL_ENABLED && nt->np.dev == dev) {
- switch (event) {
- case NETDEV_CHANGENAME:
- strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
- break;
- case NETDEV_BONDING_DESLAVE:
- case NETDEV_UNREGISTER:
- /*
- * We can't cleanup netpoll in atomic context.
- * Kick it off as deferred work.
- */
- defer_netpoll_cleanup(nt);
- }
- }
- }
- spin_unlock_irqrestore(&nts->lock, flags);
- if (event == NETDEV_UNREGISTER || event == NETDEV_BONDING_DESLAVE)
- printk(KERN_INFO "%s: network logging stopped, "
- "interface %s %s\n", nts->subsys_name, dev->name,
- event == NETDEV_UNREGISTER ? "unregistered" : "released slaves");
-
-done:
- return NOTIFY_DONE;
-}
-
static void write_msg(struct console *con, const char *msg, unsigned int len)
{
int frag, left;
@@ -841,86 +104,6 @@ static struct console netconsole = {
.write = write_msg,
};
-static int __init register_netpoll_targets(const char *subsys_name,
- struct netpoll_targets *nts,
- char *static_targets)
-{
- int err;
- struct netpoll_target *nt, *tmp;
- char *target_config;
- char *input = static_targets;
- unsigned long flags;
-
- if (strnlen(input, MAX_PARAM_LENGTH)) {
- while ((target_config = strsep(&input, ";"))) {
- nt = alloc_param_target(nts, target_config);
- if (IS_ERR(nt)) {
- err = PTR_ERR(nt);
- goto fail;
- }
-
- spin_lock_irqsave(&nts->lock, flags);
- list_add(&nt->list, &nts->list);
- spin_unlock_irqrestore(&nts->lock, flags);
- }
- }
-
- nts->netdev_notifier.notifier_call = netpoll_targets_netdev_event;
- err = register_netdevice_notifier(&nts->netdev_notifier);
- if (err)
- goto fail;
-
- nts->subsys_name = kstrdup(subsys_name, GFP_KERNEL);
- err = -ENOMEM;
- if (!nts->subsys_name)
- goto undonotifier;
-
- err = dynamic_netpoll_targets_init(subsys_name, nts);
- if (err)
- goto free_subsys_name;
-
- return 0;
-
-free_subsys_name:
- kfree(nts->subsys_name);
-undonotifier:
- unregister_netdevice_notifier(&nts->netdev_notifier);
-fail:
- /*
- * Remove all targets and destroy them (only targets created
- * from the boot/module option exist here). Skipping the list
- * lock is safe here, and netpoll_cleanup() will sleep.
- */
- list_for_each_entry_safe(nt, tmp, &nts->list, list) {
- list_del(&nt->list);
- free_param_target(nt);
- }
-
- return err;
-}
-
-static void __exit unregister_netpoll_targets(struct netpoll_targets *nts)
-{
- struct netpoll_target *nt, *tmp;
-
- dynamic_netpoll_targets_exit(nts);
- unregister_netdevice_notifier(&nts->netdev_notifier);
-
- /*
- * Targets created via configfs pin references on our module
- * and would first be rmdir(2)'ed from userspace. We reach
- * here only when they are already destroyed, and only those
- * created from the boot/module option are left, so remove and
- * destroy them. Skipping the list lock is safe here, and
- * netpoll_cleanup() will sleep.
- */
- list_for_each_entry_safe(nt, tmp, &nts->list, list) {
- list_del(&nt->list);
- free_param_target(nt);
- }
- kfree(nts->subsys_name);
-}
-
static int __init init_netconsole(void)
{
int err;
@@ -928,6 +111,7 @@ static int __init init_netconsole(void)
targets.default_local_port = 6665;
targets.default_remote_port = 6666;
+ config[MAX_PARAM_LENGTH - 1] = '\0';
err = register_netpoll_targets("netconsole", &targets, config);
if (err)
return err;
diff --git a/include/linux/netpoll_targets.h b/include/linux/netpoll_targets.h
new file mode 100644
index 0000000..d08dde0
--- /dev/null
+++ b/include/linux/netpoll_targets.h
@@ -0,0 +1,76 @@
+#ifndef _LINUX_NETPOLL_TARGETS_H
+#define _LINUX_NETPOLL_TARGETS_H
+
+#include <linux/netpoll.h>
+
+#include <linux/configfs.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+struct netpoll_targets {
+ struct list_head list;
+ spinlock_t lock;
+ u16 default_local_port, default_remote_port;
+#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
+ struct configfs_subsystem configfs_subsys;
+#endif
+ struct notifier_block netdev_notifier;
+ char *subsys_name;
+};
+#define DEFINE_NETPOLL_TARGETS(x) struct netpoll_targets x = \
+ { .list = LIST_HEAD_INIT(x.list), \
+ .lock = __SPIN_LOCK_UNLOCKED(x.lock) }
+
+#define NETPOLL_DISABLED 0
+#define NETPOLL_SETTINGUP 1
+#define NETPOLL_ENABLED 2
+#define NETPOLL_CLEANING 3
+
+/**
+ * struct netpoll_target - Represents a configured netpoll target.
+ * @list: Links this target into the netpoll_targets.list.
+ * @item: Links us into the configfs subsystem hierarchy.
+ * @np_state: Enabled / Disabled / SettingUp / Cleaning
+ * Visible from userspace (read-write) as "enabled".
+ * We maintain a state machine here of the valid states. Either a
+ * target is enabled or disabled, but it may also be in a
+ * transitional state whereby nobody is allowed to act on the
+ * target other than whoever owns the transition.
+ *
+ * Also, other parameters of a target may be modified at
+ * runtime only when it is disabled (np_state == NETPOLL_ENABLED).
+ * @np: The netpoll structure for this target.
+ * Contains the other userspace visible parameters:
+ * dev_name (read-write)
+ * local_port (read-write)
+ * remote_port (read-write)
+ * local_ip (read-write)
+ * remote_ip (read-write)
+ * local_mac (read-only)
+ * remote_mac (read-write)
+ */
+struct netpoll_target {
+ struct netpoll_targets *nts;
+ struct list_head list;
+#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
+ struct config_item item;
+#endif
+ int np_state;
+ struct netpoll np;
+ struct work_struct cleanup_work;
+};
+
+#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
+void netpoll_target_get(struct netpoll_target *nt);
+void netpoll_target_put(struct netpoll_target *nt);
+#else
+static void netpoll_target_get(struct netpoll_target *nt) {}
+static void netpoll_target_put(struct netpoll_target *nt) {}
+#endif
+
+int register_netpoll_targets(const char *subsys_name,
+ struct netpoll_targets *nts,
+ char *static_targets);
+void unregister_netpoll_targets(struct netpoll_targets *nts);
+
+#endif /* _LINUX_NETPOLL_TARGETS_H */
diff --git a/net/core/Makefile b/net/core/Makefile
index 8a04dd2..262217c 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_XFRM) += flow.o
obj-y += net-sysfs.o
obj-$(CONFIG_NET_PKTGEN) += pktgen.o
obj-$(CONFIG_NETPOLL) += netpoll.o
+obj-$(CONFIG_NETPOLL_TARGETS) += netpoll_targets.o
obj-$(CONFIG_NET_DMA) += user_dma.o
obj-$(CONFIG_FIB_RULES) += fib_rules.o
obj-$(CONFIG_TRACEPOINTS) += net-traces.o
diff --git a/net/core/netpoll_targets.c b/net/core/netpoll_targets.c
new file mode 100644
index 0000000..6817389
--- /dev/null
+++ b/net/core/netpoll_targets.c
@@ -0,0 +1,746 @@
+#include <linux/netpoll_targets.h>
+
+static void deferred_netpoll_cleanup(struct work_struct *work)
+{
+ struct netpoll_target *nt;
+ struct netpoll_targets *nts;
+ unsigned long flags;
+
+ nt = container_of(work, struct netpoll_target, cleanup_work);
+ nts = nt->nts;
+
+ netpoll_cleanup(&nt->np);
+
+ spin_lock_irqsave(&nts->lock, flags);
+ BUG_ON(nt->np_state != NETPOLL_CLEANING);
+ nt->np_state = NETPOLL_DISABLED;
+ spin_unlock_irqrestore(&nts->lock, flags);
+
+ netpoll_target_put(nt);
+}
+
+/* Allocate new target (from boot/module param) and setup netpoll for it */
+static struct netpoll_target *alloc_param_target(struct netpoll_targets *nts,
+ char *target_config)
+{
+ int err = -ENOMEM;
+ struct netpoll_target *nt;
+
+ /*
+ * Allocate and initialize with defaults.
+ * Note that these targets get their config_item fields zeroed-out.
+ */
+ nt = kzalloc(sizeof(*nt), GFP_KERNEL);
+ if (!nt) {
+ printk(KERN_ERR "%s: failed to allocate memory\n",
+ nts->subsys_name);
+ goto fail;
+ }
+
+ nt->nts = nts;
+ nt->np.name = nts->subsys_name;
+ strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
+ nt->np.local_port = nts->default_local_port;
+ nt->np.remote_port = nts->default_remote_port;
+ memset(nt->np.remote_mac, 0xff, ETH_ALEN);
+ INIT_WORK(&nt->cleanup_work, deferred_netpoll_cleanup);
+
+ /* Parse parameters and setup netpoll */
+ err = netpoll_parse_options(&nt->np, target_config);
+ if (err)
+ goto fail;
+
+ err = netpoll_setup(&nt->np);
+ if (err)
+ goto fail;
+
+ nt->np_state = NETPOLL_ENABLED;
+
+ return nt;
+
+fail:
+ kfree(nt);
+ return ERR_PTR(err);
+}
+
+/* Cleanup netpoll for given target (from boot/module param) and free it */
+static void free_param_target(struct netpoll_target *nt)
+{
+ cancel_work_sync(&nt->cleanup_work);
+ if (nt->np_state == NETPOLL_CLEANING || nt->np_state == NETPOLL_ENABLED)
+ netpoll_cleanup(&nt->np);
+ kfree(nt);
+}
+
+#ifdef CONFIG_NETPOLL_TARGETS_DYNAMIC
+
+/*
+ * Our subsystem hierarchy is:
+ *
+ * /sys/kernel/config/<subsys_name>/
+ * |
+ * <target>/
+ * | enabled
+ * | dev_name
+ * | local_port
+ * | remote_port
+ * | local_ip
+ * | remote_ip
+ * | local_mac
+ * | remote_mac
+ * |
+ * <target>/...
+ */
+
+struct netpoll_target_attr {
+ struct configfs_attribute attr;
+ ssize_t (*show)(struct netpoll_target *nt,
+ char *buf);
+ ssize_t (*store)(struct netpoll_target *nt,
+ const char *buf,
+ size_t count);
+};
+
+static struct netpoll_target *to_target(struct config_item *item)
+{
+ return item ?
+ container_of(item, struct netpoll_target, item) :
+ NULL;
+}
+
+/*
+ * Wrapper over simple_strtol (base 10) with sanity and range checking.
+ * We return (signed) long only because we may want to return errors.
+ * Do not use this to convert numbers that are allowed to be negative.
+ */
+static long strtol10_check_range(struct netpoll_targets *nts,
+ const char *cp, long min, long max)
+{
+ long ret;
+ char *p = (char *) cp;
+
+ WARN_ON(min < 0);
+ WARN_ON(max < min);
+
+ ret = simple_strtol(p, &p, 10);
+
+ if (*p && (*p != '\n')) {
+ printk(KERN_ERR "%s: invalid input\n", nts->subsys_name);
+ return -EINVAL;
+ }
+ if ((ret < min) || (ret > max)) {
+ printk(KERN_ERR "%s: input %ld must be between %ld and %ld\n",
+ nts->subsys_name, ret, min, max);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+/*
+ * Attribute operations for netpoll_target.
+ */
+
+static ssize_t show_enabled(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ nt->np_state == NETPOLL_ENABLED);
+}
+
+static ssize_t show_dev_name(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
+}
+
+static ssize_t show_local_port(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
+}
+
+static ssize_t show_remote_port(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
+}
+
+static ssize_t show_local_ip(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
+}
+
+static ssize_t show_remote_ip(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
+}
+
+static ssize_t show_local_mac(struct netpoll_target *nt, char *buf)
+{
+ struct net_device *dev = nt->np.dev;
+ static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
+ return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
+}
+
+static ssize_t show_remote_mac(struct netpoll_target *nt, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
+}
+
+/*
+ * This one is special -- targets created through the configfs interface
+ * are not enabled (and the corresponding netpoll activated) by default.
+ * The user is expected to set the desired parameters first (which
+ * would enable him to dynamically add new netpoll targets for new
+ * network interfaces as and when they come up).
+ */
+static ssize_t store_enabled(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ struct netpoll_targets *nts = nt->nts;
+ unsigned long flags;
+ int err;
+ long enabled;
+
+ enabled = strtol10_check_range(nts, buf, 0, 1);
+ if (enabled < 0)
+ return enabled;
+
+ if (enabled) { /* 1 */
+ spin_lock_irqsave(&nts->lock, flags);
+ if (nt->np_state != NETPOLL_DISABLED)
+ goto busy;
+ else {
+ nt->np_state = NETPOLL_SETTINGUP;
+ /*
+ * Nominally, we would grab an extra reference on the
+ * config_item here for dynamic targets while we let go
+ * of the lock, but this isn't required in this case
+ * because there is a reference implicitly held by the
+ * caller of the store operation.
+ */
+ spin_unlock_irqrestore(&nts->lock, flags);
+ }
+
+ /*
+ * Skip netpoll_parse_options() -- all the attributes are
+ * already configured via configfs. Just print them out.
+ */
+ netpoll_print_options(&nt->np);
+
+ err = netpoll_setup(&nt->np);
+ spin_lock_irqsave(&nts->lock, flags);
+ if (err)
+ nt->np_state = NETPOLL_DISABLED;
+ else
+ nt->np_state = NETPOLL_ENABLED;
+ spin_unlock_irqrestore(&nts->lock, flags);
+ if (err)
+ return err;
+
+ printk(KERN_INFO "%s: network logging started\n",
+ nts->subsys_name);
+ } else { /* 0 */
+ spin_lock_irqsave(&nts->lock, flags);
+ if (nt->np_state == NETPOLL_ENABLED)
+ nt->np_state = NETPOLL_CLEANING;
+ else if (nt->np_state != NETPOLL_DISABLED)
+ goto busy;
+ spin_unlock_irqrestore(&nts->lock, flags);
+
+ netpoll_cleanup(&nt->np);
+
+ spin_lock_irqsave(&nts->lock, flags);
+ nt->np_state = NETPOLL_DISABLED;
+ spin_unlock_irqrestore(&nts->lock, flags);
+ }
+
+ return strnlen(buf, count);
+busy:
+ spin_unlock_irqrestore(&nts->lock, flags);
+ return -EBUSY;
+}
+
+static ssize_t store_dev_name(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ size_t len;
+
+ strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
+
+ /* Get rid of possible trailing newline from echo(1) */
+ len = strnlen(nt->np.dev_name, IFNAMSIZ);
+ if (nt->np.dev_name[len - 1] == '\n')
+ nt->np.dev_name[len - 1] = '\0';
+
+ return strnlen(buf, count);
+}
+
+static ssize_t store_local_port(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ long local_port;
+#define __U16_MAX ((__u16) ~0U)
+
+ local_port = strtol10_check_range(nt->nts, buf, 0, __U16_MAX);
+ if (local_port < 0)
+ return local_port;
+
+ nt->np.local_port = local_port;
+
+ return strnlen(buf, count);
+}
+
+static ssize_t store_remote_port(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ long remote_port;
+#define __U16_MAX ((__u16) ~0U)
+
+ remote_port = strtol10_check_range(nt->nts, buf, 0, __U16_MAX);
+ if (remote_port < 0)
+ return remote_port;
+
+ nt->np.remote_port = remote_port;
+
+ return strnlen(buf, count);
+}
+
+static ssize_t store_local_ip(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ nt->np.local_ip = in_aton(buf);
+
+ return strnlen(buf, count);
+}
+
+static ssize_t store_remote_ip(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ nt->np.remote_ip = in_aton(buf);
+
+ return strnlen(buf, count);
+}
+
+static ssize_t store_remote_mac(struct netpoll_target *nt,
+ const char *buf,
+ size_t count)
+{
+ u8 remote_mac[ETH_ALEN];
+ char *p = (char *) buf;
+ int i;
+
+ for (i = 0; i < ETH_ALEN - 1; i++) {
+ remote_mac[i] = simple_strtoul(p, &p, 16);
+ if (*p != ':')
+ goto invalid;
+ p++;
+ }
+ remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
+ if (*p && (*p != '\n'))
+ goto invalid;
+
+ memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
+
+ return strnlen(buf, count);
+
+invalid:
+ printk(KERN_ERR "%s: invalid input\n", nt->nts->subsys_name);
+ return -EINVAL;
+}
+
+/*
+ * Attribute definitions for netpoll_target.
+ */
+
+#define __NETPOLL_TARGET_ATTR_RO(_name, _prefix_...) \
+static struct netpoll_target_attr netpoll_target_##_name = \
+ __CONFIGFS_ATTR(_name, S_IRUGO, show_##_prefix_##_name, NULL)
+
+#define __NETPOLL_TARGET_ATTR_RW(_name, _prefix_...) \
+static struct netpoll_target_attr netpoll_target_##_name = \
+ __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, \
+ show_##_prefix_##_name, store_##_prefix_##_name)
+
+#define NETPOLL_WRAP_ATTR_STORE(_name) \
+static ssize_t store_locked_##_name(struct netpoll_target *nt, \
+ const char *buf, \
+ size_t count) \
+{ \
+ struct netpoll_targets *nts = nt->nts; \
+ unsigned long flags; \
+ ssize_t ret; \
+ spin_lock_irqsave(&nts->lock, flags); \
+ if (nt->np_state != NETPOLL_DISABLED) { \
+ printk(KERN_ERR "%s: target (%s) is enabled, " \
+ "disable to update parameters\n", \
+ nts->subsys_name, \
+ config_item_name(&nt->item)); \
+ spin_unlock_irqrestore(&nts->lock, flags); \
+ return -EBUSY; \
+ } \
+ ret = store_##_name(nt, buf, count); \
+ spin_unlock_irqrestore(&nts->lock, flags); \
+ return ret; \
+}
+
+#define NETPOLL_WRAP_ATTR_SHOW(_name) \
+static ssize_t show_locked_##_name(struct netpoll_target *nt, char *buf) \
+{ \
+ struct netpoll_targets *nts = nt->nts; \
+ unsigned long flags; \
+ ssize_t ret; \
+ spin_lock_irqsave(&nts->lock, flags); \
+ ret = show_##_name(nt, buf); \
+ spin_unlock_irqrestore(&nts->lock, flags); \
+ return ret; \
+}
+
+#define NETPOLL_TARGET_ATTR_RW(_name) \
+ NETPOLL_WRAP_ATTR_STORE(_name) \
+ NETPOLL_WRAP_ATTR_SHOW(_name) \
+ __NETPOLL_TARGET_ATTR_RW(_name, locked_)
+
+#define NETPOLL_TARGET_ATTR_RO(_name) \
+ NETPOLL_WRAP_ATTR_SHOW(_name) \
+ __NETPOLL_TARGET_ATTR_RO(_name, locked_)
+
+__NETPOLL_TARGET_ATTR_RW(enabled);
+NETPOLL_TARGET_ATTR_RW(dev_name);
+NETPOLL_TARGET_ATTR_RW(local_port);
+NETPOLL_TARGET_ATTR_RW(remote_port);
+NETPOLL_TARGET_ATTR_RW(local_ip);
+NETPOLL_TARGET_ATTR_RW(remote_ip);
+NETPOLL_TARGET_ATTR_RO(local_mac);
+NETPOLL_TARGET_ATTR_RW(remote_mac);
+
+static struct configfs_attribute *netpoll_target_attrs[] = {
+ &netpoll_target_enabled.attr,
+ &netpoll_target_dev_name.attr,
+ &netpoll_target_local_port.attr,
+ &netpoll_target_remote_port.attr,
+ &netpoll_target_local_ip.attr,
+ &netpoll_target_remote_ip.attr,
+ &netpoll_target_local_mac.attr,
+ &netpoll_target_remote_mac.attr,
+ NULL,
+};
+
+/*
+ * Item operations and type for netpoll_target.
+ */
+
+static void netpoll_target_release(struct config_item *item)
+{
+ kfree(to_target(item));
+}
+
+static ssize_t netpoll_target_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -EINVAL;
+ struct netpoll_target *nt = to_target(item);
+ struct netpoll_target_attr *na =
+ container_of(attr, struct netpoll_target_attr, attr);
+
+ if (na->show)
+ ret = na->show(nt, buf);
+
+ return ret;
+}
+
+static ssize_t netpoll_target_attr_store(struct config_item *item,
+ struct configfs_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ ssize_t ret = -EINVAL;
+ struct netpoll_target *nt = to_target(item);
+ struct netpoll_target_attr *na =
+ container_of(attr, struct netpoll_target_attr, attr);
+
+ if (na->store)
+ ret = na->store(nt, buf, count);
+
+ return ret;
+}
+
+static struct configfs_item_operations netpoll_target_item_ops = {
+ .release = netpoll_target_release,
+ .show_attribute = netpoll_target_attr_show,
+ .store_attribute = netpoll_target_attr_store,
+};
+
+static struct config_item_type netpoll_target_type = {
+ .ct_attrs = netpoll_target_attrs,
+ .ct_item_ops = &netpoll_target_item_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct netpoll_targets *group_to_targets(struct config_group *group)
+{
+ struct configfs_subsystem *subsys;
+ subsys = container_of(group, struct configfs_subsystem, su_group);
+ return container_of(subsys, struct netpoll_targets, configfs_subsys);
+}
+
+/*
+ * Group operations and type for netpoll_target_subsys.
+ */
+
+static struct config_item *make_netpoll_target(struct config_group *group,
+ const char *name)
+{
+ struct netpoll_targets *nts = group_to_targets(group);
+ struct netpoll_target *nt;
+ unsigned long flags;
+
+ /*
+ * Allocate and initialize with defaults.
+ * Target is disabled at creation (enabled == 0).
+ */
+ nt = kzalloc(sizeof(*nt), GFP_KERNEL);
+ if (!nt) {
+ printk(KERN_ERR "%s: failed to allocate memory\n",
+ nts->subsys_name);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ nt->nts = nts;
+ nt->np.name = nts->subsys_name;
+ strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
+ nt->np.local_port = nts->default_local_port;
+ nt->np.remote_port = nts->default_remote_port;
+ memset(nt->np.remote_mac, 0xff, ETH_ALEN);
+ INIT_WORK(&nt->cleanup_work, deferred_netpoll_cleanup);
+
+ /* Initialize the config_item member */
+ config_item_init_type_name(&nt->item, name, &netpoll_target_type);
+
+ /* Adding, but it is disabled */
+ spin_lock_irqsave(&nts->lock, flags);
+ list_add(&nt->list, &nts->list);
+ spin_unlock_irqrestore(&nts->lock, flags);
+
+ return &nt->item;
+}
+
+static void drop_netpoll_target(struct config_group *group,
+ struct config_item *item)
+{
+ struct netpoll_targets *nts = group_to_targets(group);
+ struct netpoll_target *nt = to_target(item);
+ unsigned long flags;
+
+ spin_lock_irqsave(&nts->lock, flags);
+ list_del(&nt->list);
+ spin_unlock_irqrestore(&nts->lock, flags);
+
+ /*
+ * The target may have never been enabled, or was manually disabled
+ * before being removed so netpoll may have already been cleaned up.
+ *
+ * If it queued for cleanup already, that is fine, as that path holds a
+ * reference to the config_item.
+ */
+ if (nt->np_state == NETPOLL_ENABLED)
+ netpoll_cleanup(&nt->np);
+
+ netpoll_target_put(nt);
+}
+
+static struct configfs_group_operations netpoll_subsys_group_ops = {
+ .make_item = make_netpoll_target,
+ .drop_item = drop_netpoll_target,
+};
+
+static struct config_item_type netpoll_subsys_type = {
+ .ct_group_ops = &netpoll_subsys_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static int dynamic_netpoll_targets_init(const char *subsys_name,
+ struct netpoll_targets *nts)
+{
+ struct configfs_subsystem *subsys = &nts->configfs_subsys;
+
+ config_group_init(&subsys->su_group);
+ mutex_init(&subsys->su_mutex);
+ strncpy((char *)&subsys->su_group.cg_item.ci_namebuf, subsys_name,
+ CONFIGFS_ITEM_NAME_LEN);
+ subsys->su_group.cg_item.ci_type = &netpoll_subsys_type;
+ return configfs_register_subsystem(subsys);
+}
+
+static void dynamic_netpoll_targets_exit(struct netpoll_targets *nts)
+{
+ configfs_unregister_subsystem(&nts->configfs_subsys);
+}
+
+/*
+ * Targets that were created by parsing the boot/module option string
+ * do not exist in the configfs hierarchy (and have NULL names) and will
+ * never go away, so make these a no-op for them.
+ */
+void netpoll_target_get(struct netpoll_target *nt)
+{
+ if (config_item_name(&nt->item))
+ config_item_get(&nt->item);
+}
+EXPORT_SYMBOL_GPL(netpoll_target_get);
+
+void netpoll_target_put(struct netpoll_target *nt)
+{
+ if (config_item_name(&nt->item))
+ config_item_put(&nt->item);
+}
+EXPORT_SYMBOL_GPL(netpoll_target_put);
+
+#else /* CONFIG_NETPOLL_TARGETS_DYNAMIC */
+static int dynamic_netpoll_targets_init(const char *subsys_name,
+ struct netpoll_targets *nts) {}
+static int dynamic_netpoll_targets_exit(struct netpoll_targets *nts) {}
+#endif /* CONFIG_NETPOLL_TARGETS_DYNAMIC */
+
+/*
+ * Call netpoll_cleanup on this target asynchronously.
+ * nts->lock is required.
+ */
+static void defer_netpoll_cleanup(struct netpoll_target *nt)
+{
+ if (nt->np_state != NETPOLL_ENABLED)
+ return;
+ netpoll_target_get(nt);
+ nt->np_state = NETPOLL_CLEANING;
+ schedule_work(&nt->cleanup_work);
+}
+
+/* Handle network interface device notifications */
+static int netpoll_targets_netdev_event(struct notifier_block *this,
+ unsigned long event,
+ void *ptr)
+{
+ struct netpoll_targets *nts = container_of(this, struct netpoll_targets,
+ netdev_notifier);
+ unsigned long flags;
+ struct netpoll_target *nt;
+ struct net_device *dev = ptr;
+
+ if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
+ event == NETDEV_BONDING_DESLAVE))
+ goto done;
+
+ spin_lock_irqsave(&nts->lock, flags);
+ list_for_each_entry(nt, &nts->list, list) {
+ if (nt->np_state == NETPOLL_ENABLED && nt->np.dev == dev) {
+ switch (event) {
+ case NETDEV_CHANGENAME:
+ strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
+ break;
+ case NETDEV_BONDING_DESLAVE:
+ case NETDEV_UNREGISTER:
+ /*
+ * We can't cleanup netpoll in atomic context.
+ * Kick it off as deferred work.
+ */
+ defer_netpoll_cleanup(nt);
+ }
+ }
+ }
+ spin_unlock_irqrestore(&nts->lock, flags);
+ if (event == NETDEV_UNREGISTER || event == NETDEV_BONDING_DESLAVE)
+ printk(KERN_INFO "%s: network logging stopped, "
+ "interface %s %s\n", nts->subsys_name, dev->name,
+ event == NETDEV_UNREGISTER ? "unregistered" : "released slaves");
+
+done:
+ return NOTIFY_DONE;
+}
+
+int register_netpoll_targets(const char *subsys_name,
+ struct netpoll_targets *nts,
+ char *static_targets)
+{
+ int err;
+ struct netpoll_target *nt, *tmp;
+ char *target_config;
+ char *input = static_targets;
+ unsigned long flags;
+
+ if (strlen(input)) {
+ while ((target_config = strsep(&input, ";"))) {
+ nt = alloc_param_target(nts, target_config);
+ if (IS_ERR(nt)) {
+ err = PTR_ERR(nt);
+ goto fail;
+ }
+
+ spin_lock_irqsave(&nts->lock, flags);
+ list_add(&nt->list, &nts->list);
+ spin_unlock_irqrestore(&nts->lock, flags);
+ }
+ }
+
+ nts->netdev_notifier.notifier_call = netpoll_targets_netdev_event;
+ err = register_netdevice_notifier(&nts->netdev_notifier);
+ if (err)
+ goto fail;
+
+ nts->subsys_name = kstrdup(subsys_name, GFP_KERNEL);
+ err = -ENOMEM;
+ if (!nts->subsys_name)
+ goto undonotifier;
+
+ err = dynamic_netpoll_targets_init(subsys_name, nts);
+ if (err)
+ goto free_subsys_name;
+
+ return 0;
+
+free_subsys_name:
+ kfree(nts->subsys_name);
+undonotifier:
+ unregister_netdevice_notifier(&nts->netdev_notifier);
+fail:
+ /*
+ * Remove all targets and destroy them (only targets created
+ * from the boot/module option exist here). Skipping the list
+ * lock is safe here, and netpoll_cleanup() will sleep.
+ */
+ list_for_each_entry_safe(nt, tmp, &nts->list, list) {
+ list_del(&nt->list);
+ free_param_target(nt);
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(register_netpoll_targets);
+
+void unregister_netpoll_targets(struct netpoll_targets *nts)
+{
+ struct netpoll_target *nt, *tmp;
+
+ dynamic_netpoll_targets_exit(nts);
+ unregister_netdevice_notifier(&nts->netdev_notifier);
+
+ /*
+ * Targets created via configfs pin references on our module
+ * and would first be rmdir(2)'ed from userspace. We reach
+ * here only when they are already destroyed, and only those
+ * created from the boot/module option are left, so remove and
+ * destroy them. Skipping the list lock is safe here, and
+ * netpoll_cleanup() will sleep.
+ */
+ list_for_each_entry_safe(nt, tmp, &nts->list, list) {
+ list_del(&nt->list);
+ free_param_target(nt);
+ }
+ kfree(nts->subsys_name);
+}
+EXPORT_SYMBOL_GPL(unregister_netpoll_targets);
+
--
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