diff options
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/Kconfig | 24 | ||||
-rw-r--r-- | drivers/xen/Makefile | 2 | ||||
-rw-r--r-- | drivers/xen/balloon.c | 4 | ||||
-rw-r--r-- | drivers/xen/events.c | 20 | ||||
-rw-r--r-- | drivers/xen/features.c | 6 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 1 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 3 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.c | 55 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.h | 4 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 1 | ||||
-rw-r--r-- | drivers/xen/xenfs/Makefile | 3 | ||||
-rw-r--r-- | drivers/xen/xenfs/super.c | 64 | ||||
-rw-r--r-- | drivers/xen/xenfs/xenbus.c | 593 | ||||
-rw-r--r-- | drivers/xen/xenfs/xenfs.h | 6 |
14 files changed, 756 insertions, 30 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 4b75a16..526187c 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 d2a8fdf..ff8accc 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 526c191..8dc7109 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 1e3b934..eb0dfde 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 0707714..99eda16 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 06592b9..7d8f531 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 9678b3e..92a1ef8 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 7f24a98..773d1cf 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 e09b194..6c5e318 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 7f2f91c..e325eab 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 0000000..25275c3 --- /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 0000000..515741a --- /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 0000000..875a4c5 --- /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 0000000..51f08b2 --- /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 */ |