By request, I post my dm-userspace patch against linux-2.6.git (the
previous patch against Dan's patch).
As explained, this removes rmap (in-kernel cache) and use mmaped
buffer instead of read/write system calls for user/kernel communication.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index bf869ed..714b3b3 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -223,6 +223,12 @@ config DM_SNAPSHOT
---help---
Allow volume managers to take writable snapshots of a device.
+config DM_USERSPACE
+ tristate "Userspace target (EXPERIMENTAL)"
+ depends on BLK_DEV_DM && EXPERIMENTAL
+ ---help---
+ A target that provides a userspace interface to device-mapper
+
config DM_MIRROR
tristate "Mirror target (EXPERIMENTAL)"
depends on BLK_DEV_DM && EXPERIMENTAL
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 34957a6..a123456 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -14,6 +14,7 @@ raid456-objs := raid5.o raid6algos.o rai
raid6altivec1.o raid6altivec2.o raid6altivec4.o \
raid6altivec8.o \
raid6mmx.o raid6sse1.o raid6sse2.o
+dm-user-objs := dm-userspace.o dm-userspace-chardev.o
hostprogs-y := mktables
# Note: link order is important. All raid personalities
@@ -36,6 +37,7 @@ obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc
obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
obj-$(CONFIG_DM_MIRROR) += dm-mirror.o
obj-$(CONFIG_DM_ZERO) += dm-zero.o
+obj-$(CONFIG_DM_USERSPACE) += dm-user.o
quiet_cmd_unroll = UNROLL $@
cmd_unroll = $(PERL) $(srctree)/$(src)/unroll.pl $(UNROLL) \
diff --git a/drivers/md/dm-user.h b/drivers/md/dm-user.h
new file mode 100644
index 0000000..890e36a
--- /dev/null
+++ b/drivers/md/dm-user.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) International Business Machines Corp., 2006
+ * Author: Dan Smith <danms@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; under version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#ifndef __DM_USER_H
+#define __DM_USER_H
+
+#include <linux/hardirq.h>
+
+#define DMU_KEY_LEN 256
+
+extern spinlock_t devices_lock;
+extern struct list_head devices;
+
+/*
+ * A block device that we can send bios to
+ */
+struct target_device {
+ struct list_head list; /* Our place in the targets list */
+ struct block_device *bdev; /* The target block_device */
+ struct kref users; /* Self-destructing reference count */
+};
+
+/*
+ * A dm-userspace device, which consists of multiple targets sharing a
+ * common key
+ */
+struct dmu_device {
+ struct list_head list; /* Our place in the devices list */
+
+ spinlock_t lock; /* Protects all the fields below */
+
+ struct list_head requests; /* List of pending requests */
+ struct list_head target_devs; /* List of devices we can target */
+
+ void *transport_private; /* Private data for userspace comms */
+
+ char key[DMU_KEY_LEN]; /* Unique name string for device */
+ struct kref users; /* Self-destructing reference count */
+
+ uint64_t block_size; /* Block size for this device */
+ uint64_t block_mask; /* Mask for offset in block */
+ unsigned int block_shift; /* Shift to convert to/from block */
+
+ struct kcopyd_client *kcopy; /* Interface to kcopyd */
+};
+
+struct dmu_request {
+ struct list_head list; /* Our place in a remap bucket chain */
+ struct dmu_device *dev; /* The DMU device that owns us */
+ struct bio *bio;
+ u32 flags;
+};
+
+extern void dmu_map_done(struct dmu_device *dev, u64 id, uint32_t flags,
+ uint32_t src_maj, uint32_t src_min,
+ uint32_t dst_maj, uint32_t dst_min,
+ u64 block, u64 offset);
+
+/* Character device transport functions */
+extern int register_chardev_transport(struct dmu_device *dev);
+extern void unregister_chardev_transport(struct dmu_device *dev);
+extern int init_chardev_transport(void);
+extern void cleanup_chardev_transport(void);
+extern void write_chardev_transport_info(struct dmu_device *dev,
+ char *buf, unsigned int maxlen);
+
+extern int dmu_uspace_send_map_req(struct dmu_device *, u64, u32, u64);
+extern int dmu_uspace_send_map_status(struct dmu_device *, u64, u32);
+
+/* Increase the usage count for @dev */
+static inline void get_dev(struct dmu_device *dev)
+{
+ kref_get(&dev->users);
+}
+
+extern void destroy_dmu_device(struct kref *ref);
+/* Decrease the usage count for @dev */
+static inline void put_dev(struct dmu_device *dev)
+{
+ kref_put(&dev->users, destroy_dmu_device);
+}
+
+#endif
diff --git a/drivers/md/dm-userspace-chardev.c b/drivers/md/dm-userspace-chardev.c
new file mode 100644
index 0000000..5a4b0d3
--- /dev/null
+++ b/drivers/md/dm-userspace-chardev.c
@@ -0,0 +1,406 @@
+/*
+ * Copyright (C) International Business Machines Corp., 2006
+ * Author: Dan Smith <danms@xxxxxxxxxx>
+ *
+ * Copyright (C) 2006 FUJITA Tomonori <tomof@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; under version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/mempool.h>
+#include <linux/dm-userspace.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/poll.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <asm/uaccess.h>
+
+#include "dm.h"
+#include "dm-bio-list.h"
+#include "kcopyd.h"
+#include "dm-user.h"
+
+#define DM_MSG_PREFIX "dm-userspace"
+
+static dev_t dmu_dev;
+
+/* This allows for a cleaner separation between the dm-userspace
+ * device-mapper target, and the userspace transport used. Right now,
+ * only a chardev transport exists, but it's possible that there could
+ * be more in the future
+ */
+struct dmu_ring {
+ u32 r_idx;
+ unsigned long r_pages[DMU_RING_PAGES];
+ spinlock_t r_lock;
+};
+
+struct chardev_transport {
+ struct cdev cdev;
+ dev_t ctl_dev;
+ struct dmu_device *parent;
+
+ struct dmu_ring tx;
+ struct dmu_ring rx;
+ wait_queue_head_t tx_poll_wait;
+};
+
+static inline void dmu_ring_idx_inc(struct dmu_ring *r)
+{
+ if (r->r_idx == DMU_MAX_EVENTS - 1)
+ r->r_idx = 0;
+ else
+ r->r_idx++;
+}
+
+static struct dmu_event *dmu_head_event(struct dmu_ring *r, u32 idx)
+{
+ u32 pidx, off;
+
+ pidx = idx / DMU_EVENT_PER_PAGE;
+ off = idx % DMU_EVENT_PER_PAGE;
+
+ return (struct dmu_event *)
+ (r->r_pages[pidx] + sizeof(struct dmu_event) * off);
+}
+
+static int dmu_uspace_send_event(struct dmu_device *dev, u32 type,
+ struct dmu_event *p)
+{
+ struct chardev_transport *t = dev->transport_private;
+ struct dmu_event *ev;
+ struct dmu_ring *ring = &t->tx;
+ int err = 0;
+
+ spin_lock(&ring->r_lock);
+
+ ev = dmu_head_event(ring, ring->r_idx);
+ if (!ev->status)
+ dmu_ring_idx_inc(ring);
+ else
+ err = -EBUSY;
+
+ spin_unlock(&ring->r_lock);
+
+ if (err) {
+ DMERR("Fail to send uspace %u\n", type);
+ return err;
+ }
+
+ memcpy(ev, p, sizeof(*ev));
+ ev->type = type;
+ ev->status = 1;
+ mb();
+
+ flush_dcache_page(virt_to_page(ev));
+
+ wake_up_interruptible(&t->tx_poll_wait);
+
+ return 0;
+}
+
+int dmu_uspace_send_map_req(struct dmu_device *dev, u64 id, u32 flags, u64 block)
+{
+ struct dmu_event ev;
+
+ ev.k.map_req.id = id;
+ ev.k.map_req.flags = flags;
+ ev.k.map_req.block = block;
+ return dmu_uspace_send_event(dev, DM_USERSPACE_MAP_BLOCK_REQ, &ev);
+}
+
+int dmu_uspace_send_map_status(struct dmu_device *dev, u64 id, u32 status)
+{
+ struct dmu_event ev;
+
+ ev.k.map_done.id = id;
+ ev.k.map_done.status = status;
+ return dmu_uspace_send_event(dev, DM_USERSPACE_MAP_BLOCK_DONE, &ev);
+}
+
+static void dmu_event_recv(struct dmu_device *dev, struct dmu_event *ev)
+{
+ switch (ev->type) {
+ case DM_USERSPACE_MAP_BLOCK_RSP:
+ dmu_map_done(dev, ev->u.map_rsp.id, ev->u.map_rsp.flags,
+ ev->u.map_rsp.src_maj, ev->u.map_rsp.src_min,
+ ev->u.map_rsp.dst_maj, ev->u.map_rsp.dst_min,
+ ev->u.map_rsp.block, ev->u.map_rsp.offset);
+ break;
+ default:
+ printk("unknown type %d\n", ev->type);
+ }
+}
+
+static ssize_t dmu_ctl_write(struct file *file, const char __user * buffer,
+ size_t count, loff_t * ppos)
+{
+ struct dmu_device *dev = (struct dmu_device *)file->private_data;
+ struct chardev_transport *t = dev->transport_private;
+ struct dmu_ring *ring = &t->rx;
+ struct dmu_event *ev;
+
+ while (1) {
+ ev = dmu_head_event(ring, ring->r_idx);
+ if (!ev->status)
+ break;
+
+ /* do we need this? */
+ flush_dcache_page(virt_to_page(ev));
+
+ dmu_ring_idx_inc(ring);
+ dmu_event_recv(dev, ev);
+ ev->status = 0;
+ };
+
+ return count;
+}
+
+static void dmu_ring_free(struct dmu_ring *r)
+{
+ int i;
+ for (i = 0; i < DMU_RING_PAGES; i++)
+ free_page(r->r_pages[i]);
+}
+
+static int dmu_ring_alloc(struct dmu_ring *r)
+{
+ int i;
+
+ spin_lock_init(&r->r_lock);
+ for (i = 0; i < DMU_RING_PAGES; i++) {
+ r->r_pages[i] = get_zeroed_page(GFP_KERNEL);
+ if (!r->r_pages[i]) {
+ printk("out of memory\n");
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+
+static int dmu_ctl_open(struct inode *inode, struct file *file)
+{
+ struct chardev_transport *t;
+ struct dmu_device *dev;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ t = container_of(inode->i_cdev, struct chardev_transport, cdev);
+
+ init_waitqueue_head(&t->tx_poll_wait);
+ err = dmu_ring_alloc(&t->tx);
+ if (err)
+ goto free_tx;
+
+ err = dmu_ring_alloc(&t->rx);
+ if (err)
+ goto free_rx;
+
+ dev = t->parent;
+
+ get_dev(dev);
+
+ file->private_data = dev;
+
+ return 0;
+free_rx:
+ dmu_ring_free(&t->rx);
+free_tx:
+ dmu_ring_free(&t->tx);
+ return err;
+}
+
+static int dmu_ctl_release(struct inode *inode, struct file *file)
+{
+ struct dmu_device *dev = (struct dmu_device *)file->private_data;
+ struct chardev_transport *t = dev->transport_private;
+
+ t = container_of(inode->i_cdev, struct chardev_transport, cdev);
+
+ dmu_ring_free(&t->rx);
+ dmu_ring_free(&t->tx);
+ put_dev(dev);
+
+ return 0;
+}
+
+static unsigned dmu_ctl_poll(struct file *file, poll_table *wait)
+{
+ struct dmu_device *dev = (struct dmu_device *)file->private_data;
+ struct chardev_transport *t = dev->transport_private;
+ struct dmu_ring *ring = &t->tx;
+ struct dmu_event *ev;
+ unsigned int mask = 0;
+ u32 idx;
+
+ poll_wait(file, &t->tx_poll_wait, wait);
+
+ spin_lock(&ring->r_lock);
+
+ idx = ring->r_idx ? ring->r_idx - 1 : DMU_MAX_EVENTS - 1;
+ ev = dmu_head_event(ring, idx);
+ if (ev->status)
+ mask |= POLLIN | POLLRDNORM;
+
+ spin_unlock(&ring->r_lock);
+
+ return mask;
+}
+
+static int dmu_ring_map(struct vm_area_struct *vma, unsigned long addr,
+ struct dmu_ring *ring)
+{
+ int i, err;
+
+ for (i = 0; i < DMU_RING_PAGES; i++) {
+ struct page *page = virt_to_page(ring->r_pages[i]);
+ err = vm_insert_page(vma, addr, page);
+ if (err)
+ return err;
+ addr += PAGE_SIZE;
+ }
+
+ return 0;
+}
+
+static int dmu_ctl_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct dmu_device *dev = (struct dmu_device *)file->private_data;
+ struct chardev_transport *t = dev->transport_private;
+ unsigned long addr;
+ int err;
+
+ if (vma->vm_pgoff)
+ return -EINVAL;
+
+ if (vma->vm_end - vma->vm_start != DMU_RING_SIZE * 2) {
+ DMERR("mmap size must be %lu, not %lu \n",
+ DMU_RING_SIZE * 2, vma->vm_end - vma->vm_start);
+ return -EINVAL;
+ }
+
+ addr = vma->vm_start;
+ err = dmu_ring_map(vma, addr, &t->tx);
+ if (err)
+ return err;
+ err = dmu_ring_map(vma, addr + DMU_RING_SIZE, &t->rx);
+
+ return err;
+}
+
+static struct file_operations ctl_fops = {
+ .open = dmu_ctl_open,
+ .release = dmu_ctl_release,
+ .write = dmu_ctl_write,
+ .mmap = dmu_ctl_mmap,
+ .poll = dmu_ctl_poll,
+ .owner = THIS_MODULE,
+};
+
+static int get_free_minor(void)
+{
+ struct dmu_device *dev;
+ int minor = 0;
+
+ spin_lock(&devices_lock);
+
+ while (1) {
+ list_for_each_entry(dev, &devices, list) {
+ struct chardev_transport *t = dev->transport_private;
+ if (MINOR(t->ctl_dev) == minor)
+ goto dupe;
+ }
+ break;
+ dupe:
+ minor++;
+ }
+
+ spin_unlock(&devices_lock);
+
+ return minor;
+}
+
+int register_chardev_transport(struct dmu_device *dev)
+{
+ struct chardev_transport *t;
+ int ret;
+
+ dev->transport_private = kzalloc(sizeof(*t), GFP_KERNEL);
+ t = dev->transport_private;
+
+ if (!t) {
+ DMERR("Failed to allocate chardev transport");
+ goto bad;
+ }
+
+ t->ctl_dev = MKDEV(MAJOR(dmu_dev), get_free_minor());
+ t->parent = dev;
+
+ cdev_init(&t->cdev, &ctl_fops);
+ t->cdev.owner = THIS_MODULE;
+ t->cdev.ops = &ctl_fops;
+
+ ret = cdev_add(&t->cdev, t->ctl_dev, 1);
+ if (ret < 0) {
+ DMERR("Failed to register control device %d:%d",
+ MAJOR(t->ctl_dev), MINOR(t->ctl_dev));
+ goto bad;
+ }
+
+ return 0;
+ bad:
+ kfree(t);
+ return -ENOMEM;
+}
+
+void unregister_chardev_transport(struct dmu_device *dev)
+{
+ struct chardev_transport *t = dev->transport_private;
+
+ cdev_del(&t->cdev);
+ kfree(t);
+}
+
+int init_chardev_transport(void)
+{
+ int r;
+
+ r = alloc_chrdev_region(&dmu_dev, 0, 10, "dm-userspace");
+ if (r) {
+ DMERR("Failed to allocate chardev region");
+ return 0;
+ } else
+ return 1;
+}
+
+void cleanup_chardev_transport(void)
+{
+ unregister_chrdev_region(dmu_dev, 10);
+}
+
+void write_chardev_transport_info(struct dmu_device *dev,
+ char *buf, unsigned int maxlen)
+{
+ struct chardev_transport *t = dev->transport_private;
+
+ snprintf(buf, maxlen, "%x:%x",
+ MAJOR(t->ctl_dev), MINOR(t->ctl_dev));
+}
diff --git a/drivers/md/dm-userspace.c b/drivers/md/dm-userspace.c
new file mode 100644
index 0000000..f57df7d
--- /dev/null
+++ b/drivers/md/dm-userspace.c
@@ -0,0 +1,544 @@
+/*
+ * Copyright (C) International Business Machines Corp., 2006
+ * Author: Dan Smith <danms@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; under version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/types.h>
+#include <linux/poll.h>
+
+#include <linux/dm-userspace.h>
+
+#include "dm.h"
+#include "dm-bio-list.h"
+#include "kcopyd.h"
+#include "dm-user.h"
+
+#define DM_MSG_PREFIX "dm-userspace"
+
+#define DMU_COPY_PAGES 256
+
+static kmem_cache_t *request_cache;
+static mempool_t *request_pool;
+
+spinlock_t devices_lock;
+LIST_HEAD(devices);
+
+/* Return the block number for @sector */
+static inline u64 dmu_block(struct dmu_device *dev, sector_t sector)
+{
+ return sector >> dev->block_shift;
+}
+
+/* Return the sector offset in a block for @sector */
+static inline u64 dmu_sector_offset(struct dmu_device *dev, sector_t sector)
+{
+ return sector & dev->block_mask;
+}
+
+/* Return the starting sector for @block */
+static inline u64 dmu_sector(struct dmu_device *dev, uint64_t block)
+{
+ return block << dev->block_shift;
+}
+
+static struct target_device *find_target(struct dmu_device *dev,
+ dev_t devno)
+{
+ struct target_device *target, *match = NULL;
+
+ spin_lock(&dev->lock);
+ list_for_each_entry(target, &dev->target_devs, list) {
+ if (target->bdev->bd_dev == devno) {
+ match = target;
+ break;
+ }
+ }
+ spin_unlock(&dev->lock);
+
+ return match;
+}
+
+static struct target_device *get_target(struct dmu_device *dev,
+ dev_t devno)
+{
+
+ struct target_device *target;
+ struct block_device *bdev;
+
+ target = find_target(dev, devno);
+ if (target)
+ return target;
+
+ bdev = open_by_devnum(devno, FMODE_READ | FMODE_WRITE);
+ if (IS_ERR(bdev)) {
+ DMERR("Unable to lookup device %x", devno);
+ return NULL;
+ }
+
+ target = kmalloc(sizeof(*target), GFP_KERNEL);
+ if (!target) {
+ DMERR("Unable to alloc new target device");
+ return NULL;
+ }
+
+ target->bdev = bdev;
+ INIT_LIST_HEAD(&target->list);
+
+ spin_lock(&dev->lock);
+ list_add_tail(&target->list, &dev->target_devs);
+ spin_unlock(&dev->lock);
+
+ return target;
+}
+
+/* Caller must hold dev->lock */
+static void put_target(struct dmu_device *dev,
+ struct target_device *target)
+{
+ list_del(&target->list);
+
+ bd_release(target->bdev);
+ blkdev_put(target->bdev);
+
+ kfree(target);
+}
+
+void destroy_dmu_device(struct kref *ref)
+{
+ struct dmu_device *dev;
+ struct list_head *cursor, *next;
+
+ dev = container_of(ref, struct dmu_device, users);
+
+ spin_lock(&devices_lock);
+ list_del(&dev->list);
+ spin_unlock(&devices_lock);
+
+ list_for_each_safe(cursor, next, &dev->target_devs) {
+ struct target_device *target;
+
+ target = list_entry(cursor,
+ struct target_device,
+ list);
+
+ put_target(dev, target);
+ }
+
+ kcopyd_client_destroy(dev->kcopy);
+ unregister_chardev_transport(dev);
+
+ kfree(dev);
+}
+
+static int init_dmu_device(struct dmu_device *dev, u32 block_size)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&dev->list);
+ INIT_LIST_HEAD(&dev->requests);
+ INIT_LIST_HEAD(&dev->target_devs);
+ kref_init(&dev->users);
+ spin_lock_init(&dev->lock);
+
+ dev->block_size = block_size;
+ dev->block_mask = block_size - 1;
+ dev->block_shift = ffs(block_size) - 1;
+
+ ret = kcopyd_client_create(DMU_COPY_PAGES, &dev->kcopy);
+ if (ret) {
+ DMERR("Failed to initialize kcopyd client");
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct dmu_device *new_dmu_device(char *key,
+ struct dm_target *ti,
+ u32 block_size)
+{
+ struct dmu_device *dev;
+ int ret;
+
+ dev = kmalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ DMERR("Failed to allocate new userspace device");
+ return NULL;
+ }
+
+ if (!init_dmu_device(dev, block_size))
+ goto bad1;
+
+ snprintf(dev->key, DMU_KEY_LEN, "%s", key);
+
+ ret = register_chardev_transport(dev);
+ if (ret)
+ goto bad2;
+
+ spin_lock(&devices_lock);
+ list_add(&dev->list, &devices);
+ spin_unlock(&devices_lock);
+
+ return dev;
+ bad2:
+ put_dev(dev);
+ bad1:
+ kfree(dev);
+ DMERR("Failed to create device");
+ return NULL;
+}
+
+static struct dmu_device *find_dmu_device(const char *key)
+{
+ struct dmu_device *dev;
+ struct dmu_device *match = NULL;
+
+ spin_lock(&devices_lock);
+
+ list_for_each_entry(dev, &devices, list) {
+ spin_lock(&dev->lock);
+ if (strncmp(dev->key, key, DMU_KEY_LEN) == 0) {
+ match = dev;
+ spin_unlock(&dev->lock);
+ break;
+ }
+ spin_unlock(&dev->lock);
+ }
+
+ spin_unlock(&devices_lock);
+
+ return match;
+}
+
+static int dmu_ctr(struct dm_target *ti, unsigned int argc, char **argv)
+{
+ uint64_t block_size;
+ struct dmu_device *dev;
+ char *device_key;
+ char *block_size_param;
+ int target_idx = 2;
+
+ if (argc < 3) {
+ ti->error = "Invalid argument count";
+ return -EINVAL;
+ }
+
+ device_key = argv[0];
+ block_size_param = argv[1];
+
+ block_size = simple_strtoul(block_size_param, NULL, 10) / 512;
+
+ dev = find_dmu_device(device_key);
+ if (!dev) {
+ dev = new_dmu_device(device_key,
+ ti,
+ block_size);
+ if (!dev) {
+ ti->error = "Failed to create device";
+ goto bad;
+ }
+ } else
+ get_dev(dev);
+
+ spin_lock(&dev->lock);
+ if (dev->block_size != block_size) {
+ ti->error = "Invalid block size";
+ goto bad;
+ }
+ spin_unlock(&dev->lock);
+
+ /* Resolve target devices */
+ do {
+ int maj, min;
+ sscanf(argv[target_idx], "%i:%i", &maj, &min);
+ if (!get_target(dev, MKDEV(maj, min))) {
+ DMERR("Failed to find target device %i:%i (%s)",
+ maj, min, argv[target_idx]);
+ goto out;
+ }
+ } while (++target_idx < argc);
+
+ ti->private = dev;
+ ti->split_io = block_size;
+
+ return 0;
+
+ bad:
+ if (dev)
+ spin_unlock(&dev->lock);
+ out:
+ if (dev)
+ put_dev(dev);
+
+ return -EINVAL;
+}
+
+static void dmu_dtr(struct dm_target *ti)
+{
+ struct dmu_device *dev = (struct dmu_device *) ti->private;
+
+ put_dev(dev);
+}
+
+static int dmu_map(struct dm_target *ti, struct bio *bio,
+ union map_info *map_context)
+{
+ struct dmu_device *dev = (struct dmu_device *) ti->private;
+ struct dmu_request *req;
+ int err;
+
+ req = mempool_alloc(request_pool, GFP_NOIO);
+ if (!req) {
+ DMERR("Failed to allocate request");
+ return -1;
+ }
+
+ req->dev = dev;
+ req->bio = bio;
+
+ spin_lock(&dev->lock);
+ list_add_tail(&req->list, &dev->requests);
+ spin_unlock(&dev->lock);
+
+ err = dmu_uspace_send_map_req(dev, (u64)(unsigned long)req, 0,
+ dmu_block(dev, bio->bi_sector));
+ if (err) {
+ spin_lock(&dev->lock);
+ list_del(&req->list);
+ spin_unlock(&dev->lock);
+
+ mempool_free(req, request_pool);
+ return -1;
+ }
+ map_context->ptr = req;
+
+ return 0;
+}
+
+static int dmu_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
+{
+ struct dmu_device *dev = (struct dmu_device *) ti->private;
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+ write_chardev_transport_info(dev, result, maxlen);
+ break;
+
+ case STATUSTYPE_TABLE:
+ snprintf(result, maxlen, "%s %llu",
+ dev->key,
+ dev->block_size * 512);
+ break;
+ }
+
+ return 0;
+}
+
+static int dmu_end_io(struct dm_target *ti, struct bio *bio,
+ int error, union map_info *map_context)
+{
+ struct dmu_request *req = map_context->ptr;
+ int err;
+
+ if (req->flags & DMU_FLAG_WAITING) {
+ err = dmu_uspace_send_map_status(req->dev,
+ (u64)(unsigned long)req, 0);
+ if (err)
+ DMERR("can't send notification %llu", (u64)(unsigned long)req);
+ }
+
+ mempool_free(req, request_pool);
+ return 0;
+}
+
+static struct target_type userspace_target = {
+ .name = "userspace",
+ .version = {0, 1, 0},
+ .module = THIS_MODULE,
+ .ctr = dmu_ctr,
+ .dtr = dmu_dtr,
+ .map = dmu_map,
+ .status = dmu_status,
+ .end_io = dmu_end_io
+};
+
+static void copy_block_done(int read_err, unsigned int write_err, void *data)
+{
+ struct dmu_request *req = data;
+ generic_make_request(req->bio);
+}
+
+static void copy_block(struct dmu_device *dev, struct block_device *src_dev,
+ struct block_device *dst_dev, struct dmu_request *req,
+ u64 block, u64 offset)
+{
+ struct io_region src, dst;
+ struct kcopyd_client *client;
+
+ src.bdev = src_dev;
+ src.sector = dmu_sector(dev, dmu_block(dev, req->bio->bi_sector));
+ src.count = dev->block_size;
+
+ dst.bdev = dst_dev;
+ dst.sector = dmu_sector(dev, block);
+ dst.sector += offset;
+ dst.count = dev->block_size;
+
+ client = dev->kcopy;
+
+ kcopyd_copy(client, &src, 1, &dst, 0, copy_block_done, req);
+}
+
+void dmu_map_done(struct dmu_device *dev, u64 id, uint32_t flags,
+ uint32_t src_maj, uint32_t src_min,
+ uint32_t dst_maj, uint32_t dst_min, u64 block, u64 offset)
+{
+ struct dmu_request *cur, *next, *req = NULL;
+ struct target_device *src_dev = NULL, *dst_dev;
+ struct bio *bio;
+
+ spin_lock(&dev->lock);
+ list_for_each_entry_safe(cur, next, &dev->requests, list) {
+ if ((u64) (unsigned long)cur == id) {
+ list_del(&cur->list);
+ req = cur;
+ }
+ }
+ spin_unlock(&dev->lock);
+
+ if (!req) {
+ DMERR("can't find %llu", (unsigned long long)id);
+ return;
+ }
+
+ bio = req->bio;
+ req->flags = flags;
+
+ if (flags & DMU_FLAG_VALID) {
+ if (flags & DMU_FLAG_COPY_FIRST) {
+ src_dev = find_target(dev, MKDEV(src_maj, src_min));
+ if (!src_dev)
+ goto eio;
+ }
+
+ dst_dev = find_target(dev, MKDEV(dst_maj, dst_min));
+ if (!dst_dev)
+ goto eio;
+
+ bio->bi_sector = dmu_sector(dev, block) +
+ dmu_sector_offset(dev, bio->bi_sector) + offset;
+ bio->bi_bdev = dst_dev->bdev;
+
+ if (flags & DMU_FLAG_COPY_FIRST)
+ copy_block(dev, src_dev->bdev, dst_dev->bdev,
+ req, block, offset);
+ else
+ generic_make_request(bio);
+ }
+
+ return;
+eio:
+ bio_io_error(bio, bio->bi_size);
+}
+
+int __init dm_userspace_init(void)
+{
+ int err;
+
+ err = dm_register_target(&userspace_target);
+ if (err < 0) {
+ DMERR("Register failed %d", err);
+ return 0;
+ }
+
+ spin_lock_init(&devices_lock);
+
+ request_cache = kmem_cache_create("dm-userspace-requests",
+ sizeof(struct dmu_request),
+ __alignof__ (struct dmu_request),
+ 0, NULL, NULL);
+ if (!request_cache) {
+ DMERR("Failed to allocate request cache");
+ goto unregister_target;
+ }
+
+ request_pool = mempool_create(64,
+ mempool_alloc_slab, mempool_free_slab,
+ request_cache);
+ if (!request_pool) {
+ DMERR("Failed to allocate request pool");
+ goto request_cache_destroy;
+ }
+
+ err = init_chardev_transport();
+ if (!err)
+ goto request_pool_destroy;
+
+ return 1;
+
+request_pool_destroy:
+ mempool_destroy(request_pool);
+request_cache_destroy:
+ kmem_cache_destroy(request_cache);
+unregister_target:
+ dm_unregister_target(&userspace_target);
+ return 0;
+}
+
+void __exit dm_userspace_exit(void)
+{
+ int r;
+ struct list_head *cursor, *next;
+ struct dmu_device *dev;
+
+ spin_lock(&devices_lock);
+
+ list_for_each_safe(cursor, next, &devices) {
+ dev = list_entry(cursor, struct dmu_device, list);
+ list_del(cursor);
+ destroy_dmu_device(&dev->users);
+ DMERR("Destroying hanging device %s", dev->key);
+ }
+
+ spin_unlock(&devices_lock);
+
+ cleanup_chardev_transport();
+
+ mempool_destroy(request_pool);
+ kmem_cache_destroy(request_cache);
+
+ r = dm_unregister_target(&userspace_target);
+ if (r < 0)
+ DMERR("unregister failed %d", r);
+}
+
+module_init(dm_userspace_init);
+module_exit(dm_userspace_exit);
+
+MODULE_DESCRIPTION(DM_NAME " userspace target");
+MODULE_AUTHOR("Dan Smith");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/dm-userspace.h b/include/linux/dm-userspace.h
new file mode 100644
index 0000000..bfad3b6
--- /dev/null
+++ b/include/linux/dm-userspace.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) International Business Machines Corp., 2006
+ * Author: Dan Smith <danms@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; under version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#ifndef __DM_USERSPACE_H
+#define __DM_USERSPACE_H
+
+#include <linux/types.h>
+
+/*
+ * Message Types
+ */
+#define DM_USERSPACE_MAP_BLOCK_REQ 1
+#define DM_USERSPACE_MAP_BLOCK_RSP 2
+#define DM_USERSPACE_MAP_BLOCK_DONE 3
+
+/*
+ * Flags and associated macros
+ */
+#define DMU_FLAG_VALID (1 << 0)
+#define DMU_FLAG_RD (1 << 1)
+#define DMU_FLAG_WR (1 << 2)
+#define DMU_FLAG_COPY_FIRST (1 << 3)
+#define DMU_FLAG_SYNC (1 << 4)
+#define DMU_FLAG_WAITING (1 << 5)
+
+struct dmu_event {
+ uint32_t status;
+ uint32_t type;
+
+ /* user -> kernel */
+ union {
+ struct {
+ aligned_u64 id;
+ uint32_t flags;
+ uint32_t src_maj;
+ uint32_t src_min;
+
+ uint32_t dst_maj;
+ uint32_t dst_min;
+ aligned_u64 block;
+ aligned_u64 offset;
+ } map_rsp;
+ } u;
+
+ /* kernel -> user */
+ union {
+ struct {
+ aligned_u64 id;
+ uint32_t flags;
+ aligned_u64 block;
+ } map_req;
+ struct {
+ aligned_u64 id;
+ uint32_t status;
+ } map_done;
+ } k;
+
+} __attribute__ ((aligned (sizeof(uint64_t))));
+
+#define DMU_RING_SIZE (1UL << 16)
+#define DMU_RING_PAGES (DMU_RING_SIZE >> PAGE_SHIFT)
+#define DMU_EVENT_PER_PAGE (PAGE_SIZE / sizeof(struct dmu_event))
+#define DMU_MAX_EVENTS (DMU_EVENT_PER_PAGE * DMU_RING_PAGES)
+
+#endif
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
