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-rw-r--r--drivers/xen/Kconfig24
-rw-r--r--drivers/xen/Makefile2
-rw-r--r--drivers/xen/balloon.c4
-rw-r--r--drivers/xen/events.c20
-rw-r--r--drivers/xen/features.c6
-rw-r--r--drivers/xen/grant-table.c1
-rw-r--r--drivers/xen/xenbus/xenbus_client.c3
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c55
-rw-r--r--drivers/xen/xenbus/xenbus_probe.h4
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c1
-rw-r--r--drivers/xen/xenfs/Makefile3
-rw-r--r--drivers/xen/xenfs/super.c64
-rw-r--r--drivers/xen/xenfs/xenbus.c593
-rw-r--r--drivers/xen/xenfs/xenfs.h6
14 files changed, 756 insertions, 30 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 4b75a16de00..526187c8a12 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -17,3 +17,27 @@ config XEN_SCRUB_PAGES
is not accidentally visible to other domains. Is it more
secure, but slightly less efficient.
If in doubt, say yes.
+
+config XENFS
+ tristate "Xen filesystem"
+ depends on XEN
+ default y
+ help
+ The xen filesystem provides a way for domains to share
+ information with each other and with the hypervisor.
+ For example, by reading and writing the "xenbus" file, guests
+ may pass arbitrary information to the initial domain.
+ If in doubt, say yes.
+
+config XEN_COMPAT_XENFS
+ bool "Create compatibility mount point /proc/xen"
+ depends on XENFS
+ default y
+ help
+ The old xenstore userspace tools expect to find "xenbus"
+ under /proc/xen, but "xenbus" is now found at the root of the
+ xenfs filesystem. Selecting this causes the kernel to create
+ the compatibilty mount point /proc/xen if it is running on
+ a xen platform.
+ If in doubt, say yes.
+
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index d2a8fdf0e19..ff8accc9e10 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,5 +1,7 @@
obj-y += grant-table.o features.o events.o manage.o
obj-y += xenbus/
+
obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
obj-$(CONFIG_XEN_XENCOMM) += xencomm.o
obj-$(CONFIG_XEN_BALLOON) += balloon.o
+obj-$(CONFIG_XENFS) += xenfs/ \ No newline at end of file
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 526c191e84e..8dc7109d61b 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -44,13 +44,15 @@
#include <linux/list.h>
#include <linux/sysdev.h>
-#include <asm/xen/hypervisor.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/tlb.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+#include <xen/interface/xen.h>
#include <xen/interface/memory.h>
#include <xen/xenbus.h>
#include <xen/features.h>
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 1e3b934a4cf..eb0dfdeaa94 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -141,8 +141,9 @@ static void init_evtchn_cpu_bindings(void)
int i;
/* By default all event channels notify CPU#0. */
- for_each_irq_desc(i, desc)
+ for_each_irq_desc(i, desc) {
desc->affinity = cpumask_of_cpu(0);
+ }
#endif
memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
@@ -229,15 +230,20 @@ static void unmask_evtchn(int port)
static int find_unbound_irq(void)
{
int irq;
+ struct irq_desc *desc;
/* Only allocate from dynirq range */
- for_each_irq_nr(irq)
+ for (irq = 0; irq < nr_irqs; irq++)
if (irq_bindcount[irq] == 0)
break;
if (irq == nr_irqs)
panic("No available IRQ to bind to: increase nr_irqs!\n");
+ desc = irq_to_desc_alloc_cpu(irq, 0);
+ if (WARN_ON(desc == NULL))
+ return -1;
+
return irq;
}
@@ -579,7 +585,7 @@ void rebind_evtchn_irq(int evtchn, int irq)
spin_unlock(&irq_mapping_update_lock);
/* new event channels are always bound to cpu 0 */
- irq_set_affinity(irq, cpumask_of_cpu(0));
+ irq_set_affinity(irq, cpumask_of(0));
/* Unmask the event channel. */
enable_irq(irq);
@@ -608,9 +614,9 @@ static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
}
-static void set_affinity_irq(unsigned irq, cpumask_t dest)
+static void set_affinity_irq(unsigned irq, const struct cpumask *dest)
{
- unsigned tcpu = first_cpu(dest);
+ unsigned tcpu = cpumask_first(dest);
rebind_irq_to_cpu(irq, tcpu);
}
@@ -792,7 +798,7 @@ void xen_irq_resume(void)
mask_evtchn(evtchn);
/* No IRQ <-> event-channel mappings. */
- for_each_irq_nr(irq)
+ for (irq = 0; irq < nr_irqs; irq++)
irq_info[irq].evtchn = 0; /* zap event-channel binding */
for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
@@ -824,7 +830,7 @@ void __init xen_init_IRQ(void)
mask_evtchn(i);
/* Dynamic IRQ space is currently unbound. Zero the refcnts. */
- for_each_irq_nr(i)
+ for (i = 0; i < nr_irqs; i++)
irq_bindcount[i] = 0;
irq_ctx_init(smp_processor_id());
diff --git a/drivers/xen/features.c b/drivers/xen/features.c
index 0707714e40d..99eda169c77 100644
--- a/drivers/xen/features.c
+++ b/drivers/xen/features.c
@@ -8,7 +8,11 @@
#include <linux/types.h>
#include <linux/cache.h>
#include <linux/module.h>
-#include <asm/xen/hypervisor.h>
+
+#include <asm/xen/hypercall.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/version.h>
#include <xen/features.h>
u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 06592b9da83..7d8f531fb8e 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -40,6 +40,7 @@
#include <xen/interface/xen.h>
#include <xen/page.h>
#include <xen/grant_table.h>
+#include <asm/xen/hypercall.h>
#include <asm/pgtable.h>
#include <asm/sync_bitops.h>
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 9678b3e98c6..92a1ef80a28 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -136,7 +136,6 @@ EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
/**
* xenbus_switch_state
* @dev: xenbus device
- * @xbt: transaction handle
* @state: new state
*
* Advertise in the store a change of the given driver to the given new_state.
@@ -267,7 +266,7 @@ EXPORT_SYMBOL_GPL(xenbus_dev_error);
* @fmt: error message format
*
* Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
- * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly
+ * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
* closedown of this driver and its peer.
*/
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 7f24a98a446..773d1cf2328 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -40,6 +40,7 @@
#include <linux/ctype.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
+#include <linux/proc_fs.h>
#include <linux/notifier.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
@@ -55,7 +56,10 @@
#include "xenbus_comms.h"
#include "xenbus_probe.h"
+
int xen_store_evtchn;
+EXPORT_SYMBOL(xen_store_evtchn);
+
struct xenstore_domain_interface *xen_store_interface;
static unsigned long xen_store_mfn;
@@ -99,15 +103,15 @@ static int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env)
}
/* device/<type>/<id> => <type>-<id> */
-static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename)
+static int frontend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename)
{
nodename = strchr(nodename, '/');
- if (!nodename || strlen(nodename + 1) >= BUS_ID_SIZE) {
+ if (!nodename || strlen(nodename + 1) >= XEN_BUS_ID_SIZE) {
printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename);
return -EINVAL;
}
- strlcpy(bus_id, nodename + 1, BUS_ID_SIZE);
+ strlcpy(bus_id, nodename + 1, XEN_BUS_ID_SIZE);
if (!strchr(bus_id, '/')) {
printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id);
return -EINVAL;
@@ -166,6 +170,9 @@ static int read_backend_details(struct xenbus_device *xendev)
return read_otherend_details(xendev, "backend-id", "backend");
}
+static struct device_attribute xenbus_dev_attrs[] = {
+ __ATTR_NULL
+};
/* Bus type for frontend drivers. */
static struct xen_bus_type xenbus_frontend = {
@@ -174,12 +181,13 @@ static struct xen_bus_type xenbus_frontend = {
.get_bus_id = frontend_bus_id,
.probe = xenbus_probe_frontend,
.bus = {
- .name = "xen",
- .match = xenbus_match,
- .uevent = xenbus_uevent,
- .probe = xenbus_dev_probe,
- .remove = xenbus_dev_remove,
- .shutdown = xenbus_dev_shutdown,
+ .name = "xen",
+ .match = xenbus_match,
+ .uevent = xenbus_uevent,
+ .probe = xenbus_dev_probe,
+ .remove = xenbus_dev_remove,
+ .shutdown = xenbus_dev_shutdown,
+ .dev_attrs = xenbus_dev_attrs,
},
};
@@ -460,6 +468,7 @@ int xenbus_probe_node(struct xen_bus_type *bus,
const char *type,
const char *nodename)
{
+ char devname[XEN_BUS_ID_SIZE];
int err;
struct xenbus_device *xendev;
size_t stringlen;
@@ -494,10 +503,12 @@ int xenbus_probe_node(struct xen_bus_type *bus,
xendev->dev.bus = &bus->bus;
xendev->dev.release = xenbus_dev_release;
- err = bus->get_bus_id(xendev->dev.bus_id, xendev->nodename);
+ err = bus->get_bus_id(devname, xendev->nodename);
if (err)
goto fail;
+ dev_set_name(&xendev->dev, devname);
+
/* Register with generic device framework. */
err = device_register(&xendev->dev);
if (err)
@@ -611,7 +622,7 @@ void xenbus_dev_changed(const char *node, struct xen_bus_type *bus)
{
int exists, rootlen;
struct xenbus_device *dev;
- char type[BUS_ID_SIZE];
+ char type[XEN_BUS_ID_SIZE];
const char *p, *root;
if (char_count(node, '/') < 2)
@@ -625,8 +636,8 @@ void xenbus_dev_changed(const char *node, struct xen_bus_type *bus)
/* backend/<type>/... or device/<type>/... */
p = strchr(node, '/') + 1;
- snprintf(type, BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p);
- type[BUS_ID_SIZE-1] = '\0';
+ snprintf(type, XEN_BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p);
+ type[XEN_BUS_ID_SIZE-1] = '\0';
rootlen = strsep_len(node, '/', bus->levels);
if (rootlen < 0)
@@ -674,7 +685,7 @@ static int suspend_dev(struct device *dev, void *data)
err = drv->suspend(xdev);
if (err)
printk(KERN_WARNING
- "xenbus: suspend %s failed: %i\n", dev->bus_id, err);
+ "xenbus: suspend %s failed: %i\n", dev_name(dev), err);
return 0;
}
@@ -695,7 +706,7 @@ static int suspend_cancel_dev(struct device *dev, void *data)
if (err)
printk(KERN_WARNING
"xenbus: suspend_cancel %s failed: %i\n",
- dev->bus_id, err);
+ dev_name(dev), err);
return 0;
}
@@ -717,7 +728,7 @@ static int resume_dev(struct device *dev, void *data)
if (err) {
printk(KERN_WARNING
"xenbus: resume (talk_to_otherend) %s failed: %i\n",
- dev->bus_id, err);
+ dev_name(dev), err);
return err;
}
@@ -728,7 +739,7 @@ static int resume_dev(struct device *dev, void *data)
if (err) {
printk(KERN_WARNING
"xenbus: resume %s failed: %i\n",
- dev->bus_id, err);
+ dev_name(dev), err);
return err;
}
}
@@ -737,7 +748,7 @@ static int resume_dev(struct device *dev, void *data)
if (err) {
printk(KERN_WARNING
"xenbus_probe: resume (watch_otherend) %s failed: "
- "%d.\n", dev->bus_id, err);
+ "%d.\n", dev_name(dev), err);
return err;
}
@@ -849,6 +860,14 @@ static int __init xenbus_probe_init(void)
if (!xen_initial_domain())
xenbus_probe(NULL);
+#ifdef CONFIG_XEN_COMPAT_XENFS
+ /*
+ * Create xenfs mountpoint in /proc for compatibility with
+ * utilities that expect to find "xenbus" under "/proc/xen".
+ */
+ proc_mkdir("xen", NULL);
+#endif
+
return 0;
out_unreg_back:
diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h
index e09b19415a4..6c5e3185a6a 100644
--- a/drivers/xen/xenbus/xenbus_probe.h
+++ b/drivers/xen/xenbus/xenbus_probe.h
@@ -34,6 +34,8 @@
#ifndef _XENBUS_PROBE_H
#define _XENBUS_PROBE_H
+#define XEN_BUS_ID_SIZE 20
+
#ifdef CONFIG_XEN_BACKEND
extern void xenbus_backend_suspend(int (*fn)(struct device *, void *));
extern void xenbus_backend_resume(int (*fn)(struct device *, void *));
@@ -52,7 +54,7 @@ struct xen_bus_type
{
char *root;
unsigned int levels;
- int (*get_bus_id)(char bus_id[BUS_ID_SIZE], const char *nodename);
+ int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
int (*probe)(const char *type, const char *dir);
struct bus_type bus;
};
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 7f2f91c0e11..e325eab4724 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -184,6 +184,7 @@ void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg)
return ret;
}
+EXPORT_SYMBOL(xenbus_dev_request_and_reply);
/* Send message to xs, get kmalloc'ed reply. ERR_PTR() on error. */
static void *xs_talkv(struct xenbus_transaction t,
diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile
new file mode 100644
index 00000000000..25275c3bbdf
--- /dev/null
+++ b/drivers/xen/xenfs/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_XENFS) += xenfs.o
+
+xenfs-objs = super.o xenbus.o \ No newline at end of file
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
new file mode 100644
index 00000000000..515741a8e6b
--- /dev/null
+++ b/drivers/xen/xenfs/super.c
@@ -0,0 +1,64 @@
+/*
+ * xenfs.c - a filesystem for passing info between the a domain and
+ * the hypervisor.
+ *
+ * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
+ * and /proc/xen compatibility mount point.
+ * Turned xenfs into a loadable module.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/magic.h>
+
+#include "xenfs.h"
+
+#include <asm/xen/hypervisor.h>
+
+MODULE_DESCRIPTION("Xen filesystem");
+MODULE_LICENSE("GPL");
+
+static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ static struct tree_descr xenfs_files[] = {
+ [2] = {"xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR},
+ {""},
+ };
+
+ return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files);
+}
+
+static int xenfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data, struct vfsmount *mnt)
+{
+ return get_sb_single(fs_type, flags, data, xenfs_fill_super, mnt);
+}
+
+static struct file_system_type xenfs_type = {
+ .owner = THIS_MODULE,
+ .name = "xenfs",
+ .get_sb = xenfs_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static int __init xenfs_init(void)
+{
+ if (xen_pv_domain())
+ return register_filesystem(&xenfs_type);
+
+ printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
+ return 0;
+}
+
+static void __exit xenfs_exit(void)
+{
+ if (xen_pv_domain())
+ unregister_filesystem(&xenfs_type);
+}
+
+module_init(xenfs_init);
+module_exit(xenfs_exit);
+
diff --git a/drivers/xen/xenfs/xenbus.c b/drivers/xen/xenfs/xenbus.c
new file mode 100644
index 00000000000..875a4c59c59
--- /dev/null
+++ b/drivers/xen/xenfs/xenbus.c
@@ -0,0 +1,593 @@
+/*
+ * Driver giving user-space access to the kernel's xenbus connection
+ * to xenstore.
+ *
+ * Copyright (c) 2005, Christian Limpach
+ * Copyright (c) 2005, Rusty Russell, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Changes:
+ * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem
+ * and /proc/xen compatibility mount point.
+ * Turned xenfs into a loadable module.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/uio.h>
+#include <linux/notifier.h>
+#include <linux/wait.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/string.h>
+
+#include "xenfs.h"
+#include "../xenbus/xenbus_comms.h"
+
+#include <xen/xenbus.h>
+#include <asm/xen/hypervisor.h>
+
+/*
+ * An element of a list of outstanding transactions, for which we're
+ * still waiting a reply.
+ */
+struct xenbus_transaction_holder {
+ struct list_head list;
+ struct xenbus_transaction handle;
+};
+
+/*
+ * A buffer of data on the queue.
+ */
+struct read_buffer {
+ struct list_head list;
+ unsigned int cons;
+ unsigned int len;
+ char msg[];
+};
+
+struct xenbus_file_priv {
+ /*
+ * msgbuffer_mutex is held while partial requests are built up
+ * and complete requests are acted on. It therefore protects
+ * the "transactions" and "watches" lists, and the partial
+ * request length and buffer.
+ *
+ * reply_mutex protects the reply being built up to return to
+ * usermode. It nests inside msgbuffer_mutex but may be held
+ * alone during a watch callback.
+ */
+ struct mutex msgbuffer_mutex;
+
+ /* In-progress transactions */
+ struct list_head transactions;
+
+ /* Active watches. */
+ struct list_head watches;
+
+ /* Partial request. */
+ unsigned int len;
+ union {
+ struct xsd_sockmsg msg;
+ char buffer[PAGE_SIZE];
+ } u;
+
+ /* Response queue. */
+ struct mutex reply_mutex;
+ struct list_head read_buffers;
+ wait_queue_head_t read_waitq;
+
+};
+
+/* Read out any raw xenbus messages queued up. */
+static ssize_t xenbus_file_read(struct file *filp,
+ char __user *ubuf,
+ size_t len, loff_t *ppos)
+{
+ struct xenbus_file_priv *u = filp->private_data;
+ struct read_buffer *rb;
+ unsigned i;
+ int ret;
+
+ mutex_lock(&u->reply_mutex);
+ while (list_empty(&u->read_buffers)) {
+ mutex_unlock(&u->reply_mutex);
+ ret = wait_event_interruptible(u->read_waitq,
+ !list_empty(&u->read_buffers));
+ if (ret)
+ return ret;
+ mutex_lock(&u->reply_mutex);
+ }
+
+ rb = list_entry(u->read_buffers.next, struct read_buffer, list);
+ i = 0;
+ while (i < len) {
+ unsigned sz = min((unsigned)len - i, rb->len - rb->cons);
+
+ ret = copy_to_user(ubuf + i, &rb->msg[rb->cons], sz);
+
+ i += sz - ret;
+ rb->cons += sz - ret;
+
+ if (ret != sz) {
+ if (i == 0)
+ i = -EFAULT;
+ goto out;
+ }
+
+ /* Clear out buffer if it has been consumed */
+ if (rb->cons == rb->len) {
+ list_del(&rb->list);
+ kfree(rb);
+ if (list_empty(&u->read_buffers))
+ break;
+ rb = list_entry(u->read_buffers.next,
+ struct read_buffer, list);
+ }
+ }
+
+out:
+ mutex_unlock(&u->reply_mutex);
+ return i;
+}
+
+/*
+ * Add a buffer to the queue. Caller must hold the appropriate lock
+ * if the queue is not local. (Commonly the caller will build up
+ * multiple queued buffers on a temporary local list, and then add it
+ * to the appropriate list under lock once all the buffers have een
+ * successfully allocated.)
+ */
+static int queue_reply(struct list_head *queue, const void *data, size_t len)
+{
+ struct read_buffer *rb;
+
+ if (len == 0)
+ return 0;
+
+ rb = kmalloc(sizeof(*rb) + len, GFP_KERNEL);
+ if (rb == NULL)
+ return -ENOMEM;
+
+ rb->cons = 0;
+ rb->len = len;
+
+ memcpy(rb->msg, data, len);
+
+ list_add_tail(&rb->list, queue);
+ return 0;
+}
+
+/*
+ * Free all the read_buffer s on a list.
+ * Caller must have sole reference to list.
+ */
+static void queue_cleanup(struct list_head *list)
+{
+ struct read_buffer *rb;
+
+ while (!list_empty(list)) {
+ rb = list_entry(list->next, struct read_buffer, list);
+ list_del(list->next);
+ kfree(rb);
+ }
+}
+
+struct watch_adapter {
+ struct list_head list;
+ struct xenbus_watch watch;
+ struct xenbus_file_priv *dev_data;
+ char *token;
+};
+
+static void free_watch_adapter(struct watch_adapter *watch)
+{
+ kfree(watch->watch.node);
+ kfree(watch->token);
+ kfree(watch);
+}
+
+static struct watch_adapter *alloc_watch_adapter(const char *path,
+ const char *token)
+{
+ struct watch_adapter *watch;
+
+ watch = kzalloc(sizeof(*watch), GFP_KERNEL);
+ if (watch == NULL)
+ goto out_fail;
+
+ watch->watch.node = kstrdup(path, GFP_KERNEL);
+ if (watch->watch.node == NULL)
+ goto out_free;
+
+ watch->token = kstrdup(token, GFP_KERNEL);
+ if (watch->token == NULL)
+ goto out_free;
+
+ return watch;
+
+out_free:
+ free_watch_adapter(watch);
+
+out_fail:
+ return NULL;
+}
+
+static void watch_fired(struct xenbus_watch *watch,
+ const char **vec,
+ unsigned int len)
+{
+ struct watch_adapter *adap;
+ struct xsd_sockmsg hdr;
+ const char *path, *token;
+ int path_len, tok_len, body_len, data_len = 0;
+ int ret;
+ LIST_HEAD(staging_q);
+
+ adap = container_of(watch, struct watch_adapter, watch);
+
+ path = vec[XS_WATCH_PATH];
+ token = adap->token;
+
+ path_len = strlen(path) + 1;
+ tok_len = strlen(token) + 1;
+ if (len > 2)
+ data_len = vec[len] - vec[2] + 1;
+ body_len = path_len + tok_len + data_len;
+
+ hdr.type = XS_WATCH_EVENT;
+ hdr.len = body_len;
+
+ mutex_lock(&adap->dev_data->reply_mutex);
+
+ ret = queue_reply(&staging_q, &hdr, sizeof(hdr));
+ if (!ret)
+ ret = queue_reply(&staging_q, path, path_len);
+ if (!ret)
+ ret = queue_reply(&staging_q, token, tok_len);
+ if (!ret && len > 2)
+ ret = queue_reply(&staging_q, vec[2], data_len);
+
+ if (!ret) {
+ /* success: pass reply list onto watcher */
+ list_splice_tail(&staging_q, &adap->dev_data->read_buffers);
+ wake_up(&adap->dev_data->read_waitq);
+ } else
+ queue_cleanup(&staging_q);
+
+ mutex_unlock(&adap->dev_data->reply_mutex);
+}
+
+static int xenbus_write_transaction(unsigned msg_type,
+ struct xenbus_file_priv *u)
+{
+ int rc, ret;
+ void *reply;
+ struct xenbus_transaction_holder *trans = NULL;
+ LIST_HEAD(staging_q);
+
+ if (msg_type == XS_TRANSACTION_START) {
+ trans = kmalloc(sizeof(*trans), GFP_KERNEL);
+ if (!trans) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ }
+
+ reply = xenbus_dev_request_and_reply(&u->u.msg);
+ if (IS_ERR(reply)) {
+ kfree(trans);
+ rc = PTR_ERR(reply);
+ goto out;
+ }
+
+ if (msg_type == XS_TRANSACTION_START) {
+ trans->handle.id = simple_strtoul(reply, NULL, 0);
+
+ list_add(&trans->list, &u->transactions);
+ } else if (msg_type == XS_TRANSACTION_END) {
+ list_for_each_entry(trans, &u->transactions, list)
+ if (trans->handle.id == u->u.msg.tx_id)
+ break;
+ BUG_ON(&trans->list == &u->transactions);
+ list_del(&trans->list);
+
+ kfree(trans);
+ }
+
+ mutex_lock(&u->reply_mutex);
+ ret = queue_reply(&staging_q, &u->u.msg, sizeof(u->u.msg));
+ if (!ret)
+ ret = queue_reply(&staging_q, reply, u->u.msg.len);
+ if (!ret) {
+ list_splice_tail(&staging_q, &u->read_buffers);
+ wake_up(&u->read_waitq);
+ } else {
+ queue_cleanup(&staging_q);
+ rc = ret;
+ }
+ mutex_unlock(&u->reply_mutex);
+
+ kfree(reply);
+
+out:
+ return rc;
+}
+
+static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
+{
+ struct watch_adapter *watch, *tmp_watch;
+ char *path, *token;
+ int err, rc;
+ LIST_HEAD(staging_q);
+
+ path = u->u.buffer + sizeof(u->u.msg);
+ token = memchr(path, 0, u->u.msg.len);
+ if (token == NULL) {
+ rc = -EILSEQ;
+ goto out;
+ }
+ token++;
+
+ if (msg_type == XS_WATCH) {
+ watch = alloc_watch_adapter(path, token);
+ if (watch == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ watch->watch.callback = watch_fired;
+ watch->dev_data = u;
+
+ err = register_xenbus_watch(&watch->watch);
+ if (err) {
+ free_watch_adapter(watch);
+ rc = err;
+ goto out;
+ }
+ list_add(&watch->list, &u->watches);
+ } else {
+ list_for_each_entry_safe(watch, tmp_watch, &u->watches, list) {
+ if (!strcmp(watch->token, token) &&
+ !strcmp(watch->watch.node, path)) {
+ unregister_xenbus_watch(&watch->watch);
+ list_del(&watch->list);
+ free_watch_adapter(watch);
+ break;
+ }
+ }
+ }
+
+ /* Success. Synthesize a reply to say all is OK. */
+ {
+ struct {
+ struct xsd_sockmsg hdr;
+ char body[3];
+ } __packed reply = {
+ {
+ .type = msg_type,
+ .len = sizeof(reply.body)
+ },
+ "OK"
+ };
+
+ mutex_lock(&u->reply_mutex);
+ rc = queue_reply(&u->read_buffers, &reply, sizeof(reply));
+ mutex_unlock(&u->reply_mutex);
+ }
+
+out:
+ return rc;
+}
+
+static ssize_t xenbus_file_write(struct file *filp,
+ const char __user *ubuf,
+ size_t len, loff_t *ppos)
+{
+ struct xenbus_file_priv *u = filp->private_data;
+ uint32_t msg_type;
+ int rc = len;
+ int ret;
+ LIST_HEAD(staging_q);
+
+ /*
+ * We're expecting usermode to be writing properly formed
+ * xenbus messages. If they write an incomplete message we
+ * buffer it up. Once it is complete, we act on it.
+ */
+
+ /*
+ * Make sure concurrent writers can't stomp all over each
+ * other's messages and make a mess of our partial message
+ * buffer. We don't make any attemppt to stop multiple
+ * writers from making a mess of each other's incomplete
+ * messages; we're just trying to guarantee our own internal
+ * consistency and make sure that single writes are handled
+ * atomically.
+ */
+ mutex_lock(&u->msgbuffer_mutex);
+
+ /* Get this out of the way early to avoid confusion */
+ if (len == 0)
+ goto out;
+
+ /* Can't write a xenbus message larger we can buffer */
+ if ((len + u->len) > sizeof(u->u.buffer)) {
+ /* On error, dump existing buffer */
+ u->len = 0;
+ rc = -EINVAL;
+ goto out;
+ }
+
+ ret = copy_from_user(u->u.buffer + u->len, ubuf, len);
+
+ if (ret == len) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ /* Deal with a partial copy. */
+ len -= ret;
+ rc = len;
+
+ u->len += len;
+
+ /* Return if we haven't got a full message yet */
+ if (u->len < sizeof(u->u.msg))
+ goto out; /* not even the header yet */
+
+ /* If we're expecting a message that's larger than we can
+ possibly send, dump what we have and return an error. */
+ if ((sizeof(u->u.msg) + u->u.msg.len) > sizeof(u->u.buffer)) {
+ rc = -E2BIG;
+ u->len = 0;
+ goto out;
+ }
+
+ if (u->len < (sizeof(u->u.msg) + u->u.msg.len))
+ goto out; /* incomplete data portion */
+
+ /*
+ * OK, now we have a complete message. Do something with it.
+ */
+
+ msg_type = u->u.msg.type;
+
+ switch (msg_type) {
+ case XS_TRANSACTION_START:
+ case XS_TRANSACTION_END:
+ case XS_DIRECTORY:
+ case XS_READ:
+ case XS_GET_PERMS:
+ case XS_RELEASE:
+ case XS_GET_DOMAIN_PATH:
+ case XS_WRITE:
+ case XS_MKDIR:
+ case XS_RM:
+ case XS_SET_PERMS:
+ /* Send out a transaction */
+ ret = xenbus_write_transaction(msg_type, u);
+ break;
+
+ case XS_WATCH:
+ case XS_UNWATCH:
+ /* (Un)Ask for some path to be watched for changes */
+ ret = xenbus_write_watch(msg_type, u);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ if (ret != 0)
+ rc = ret;
+
+ /* Buffered message consumed */
+ u->len = 0;
+
+ out:
+ mutex_unlock(&u->msgbuffer_mutex);
+ return rc;
+}
+
+static int xenbus_file_open(struct inode *inode, struct file *filp)
+{
+ struct xenbus_file_priv *u;
+
+ if (xen_store_evtchn == 0)
+ return -ENOENT;
+
+ nonseekable_open(inode, filp);
+
+ u = kzalloc(sizeof(*u), GFP_KERNEL);
+ if (u == NULL)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&u->transactions);
+ INIT_LIST_HEAD(&u->watches);
+ INIT_LIST_HEAD(&u->read_buffers);
+ init_waitqueue_head(&u->read_waitq);
+
+ mutex_init(&u->reply_mutex);
+ mutex_init(&u->msgbuffer_mutex);
+
+ filp->private_data = u;
+
+ return 0;
+}
+
+static int xenbus_file_release(struct inode *inode, struct file *filp)
+{
+ struct xenbus_file_priv *u = filp->private_data;
+ struct xenbus_transaction_holder *trans, *tmp;
+ struct watch_adapter *watch, *tmp_watch;
+
+ /*
+ * No need for locking here because there are no other users,
+ * by definition.
+ */
+
+ list_for_each_entry_safe(trans, tmp, &u->transactions, list) {
+ xenbus_transaction_end(trans->handle, 1);
+ list_del(&trans->list);
+ kfree(trans);
+ }
+
+ list_for_each_entry_safe(watch, tmp_watch, &u->watches, list) {
+ unregister_xenbus_watch(&watch->watch);
+ list_del(&watch->list);
+ free_watch_adapter(watch);
+ }
+
+ kfree(u);
+
+ return 0;
+}
+
+static unsigned int xenbus_file_poll(struct file *file, poll_table *wait)
+{
+ struct xenbus_file_priv *u = file->private_data;
+
+ poll_wait(file, &u->read_waitq, wait);
+ if (!list_empty(&u->read_buffers))
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+
+const struct file_operations xenbus_file_ops = {
+ .read = xenbus_file_read,
+ .write = xenbus_file_write,
+ .open = xenbus_file_open,
+ .release = xenbus_file_release,
+ .poll = xenbus_file_poll,
+};
diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h
new file mode 100644
index 00000000000..51f08b2d0bf
--- /dev/null
+++ b/drivers/xen/xenfs/xenfs.h
@@ -0,0 +1,6 @@
+#ifndef _XENFS_XENBUS_H
+#define _XENFS_XENBUS_H
+
+extern const struct file_operations xenbus_file_ops;
+
+#endif /* _XENFS_XENBUS_H */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 18:39:10 +0000