From 43e57ce5e11e9052f5a7db66f2e8613f1784f919 Mon Sep 17 00:00:00 2001 From: Frederic Robra Date: Tue, 25 Jun 2019 17:03:28 +0200 Subject: first version of dnbd3-ng --- src/kernel/core.c | 484 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 484 insertions(+) create mode 100644 src/kernel/core.c (limited to 'src/kernel/core.c') diff --git a/src/kernel/core.c b/src/kernel/core.c new file mode 100644 index 0000000..bfa8d22 --- /dev/null +++ b/src/kernel/core.c @@ -0,0 +1,484 @@ +/* + * This file is part of the Distributed Network Block Device 3 + * + * Copyright(c) 2019 Frederic Robra + * Parts copyright 2011-2012 Johann Latocha + * + * This file may be licensed under the terms of of the + * GNU General Public License Version 2 (the ``GPL''). + * + * Software distributed under the License is distributed + * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either + * express or implied. See the GPL for the specific language + * governing rights and limitations. + * + * You should have received a copy of the GPL along with this + * program. If not, go to http://www.gnu.org/licenses/gpl.html + * or write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "dnbd3.h" +#include "clientconfig.h" +#include "sysfs.h" + +static DEFINE_IDR(dnbd3_index_idr); +static DEFINE_MUTEX(dnbd3_index_mutex); + +static unsigned int max_devs = NUMBER_DEVICES; +static dnbd3_device_t *dnbd3_device; +int major; + + +static int dnbd3_open(struct block_device *bdev, fmode_t mode) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_open"); + + return 0; +} + +static void dnbd3_release(struct gendisk *disk, fmode_t mode) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_release"); + +} + + +void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_blk_fail_all_requests"); +} + + +int dnbd3_net_connect(dnbd3_device_t *dev) +{ + return 0; +} + + +int dnbd3_net_disconnect(dnbd3_device_t *dev) +{ + return 0; +} + +static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_ioctl"); + + int result = -100; + dnbd3_device_t *dev = bdev->bd_disk->private_data; + char *imgname = NULL; + dnbd3_ioctl_t *msg = NULL; + //unsigned long irqflags; + + while (dev->disconnecting) + { + // do nothing + } + + if (arg != 0) + { + msg = kmalloc(sizeof(*msg), GFP_KERNEL); + if (msg == NULL) return -ENOMEM; + if (copy_from_user((char *)msg, (char *)arg, 2) != 0 || msg->len != sizeof(*msg)) + { + result = -ENOEXEC; + goto cleanup_return; + } + if (copy_from_user((char *)msg, (char *)arg, sizeof(*msg)) != 0) + { + result = -ENOENT; + goto cleanup_return; + } + if (msg->imgname != NULL && msg->imgnamelen > 0) + { + imgname = kmalloc(msg->imgnamelen + 1, GFP_KERNEL); + if (imgname == NULL) + { + result = -ENOMEM; + goto cleanup_return; + } + if (copy_from_user(imgname, msg->imgname, msg->imgnamelen) != 0) + { + result = -ENOENT; + goto cleanup_return; + } + imgname[msg->imgnamelen] = '\0'; + //printk("IOCTL Image name of len %d is %s\n", (int)msg->imgnamelen, imgname); + } + } + + + switch (cmd) + { + case IOCTL_OPEN: + if (dev->imgname != NULL) + { + result = -EBUSY; + } + else if (imgname == NULL) + { + result = -EINVAL; + } + else if (msg == NULL) + { + result = -EINVAL; + } + else + { + if (sizeof(msg->host) != sizeof(dev->cur_server.host)) + printk("Odd size bug#1 triggered in IOCTL\n"); + memcpy(&dev->cur_server.host, &msg->host, sizeof(msg->host)); + dev->cur_server.failures = 0; + memcpy(&dev->initial_server, &dev->cur_server, sizeof(dev->initial_server)); + dev->imgname = imgname; + dev->rid = msg->rid; + dev->use_server_provided_alts = msg->use_server_provided_alts; + // Forget all alt servers on explicit connect, set first al server to initial server + memset(dev->alt_servers, 0, sizeof(dev->alt_servers[0])*NUMBER_SERVERS); + memcpy(dev->alt_servers, &dev->initial_server, sizeof(dev->alt_servers[0])); +//#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0) +// if (blk_queue->backing_dev_info != NULL) { +// blk_queue->backing_dev_info->ra_pages = (msg->read_ahead_kb * 1024) / PAGE_SIZE; +// } +//#else +// blk_queue->backing_dev_info.ra_pages = (msg->read_ahead_kb * 1024) / PAGE_SIZE; +//#endif + if (dnbd3_net_connect(dev) == 0) + { + result = 0; + imgname = NULL; // Prevent kfree at the end + } + else + { + result = -ENOENT; + dev->imgname = NULL; + } + } + break; + + case IOCTL_CLOSE: + dnbd3_blk_fail_all_requests(dev); + result = dnbd3_net_disconnect(dev); + dnbd3_blk_fail_all_requests(dev); + set_capacity(dev->disk, 0); + if (dev->imgname) + { + kfree(dev->imgname); + dev->imgname = NULL; + } + break; + + case IOCTL_SWITCH: + result = -EINVAL; + break; + + case IOCTL_ADD_SRV: + case IOCTL_REM_SRV: + if (dev->imgname == NULL) + { + result = -ENOENT; + } + else if (dev->new_servers_num >= NUMBER_SERVERS) + { + result = -EAGAIN; + } + else if (msg == NULL) + { + result = -EINVAL; + } + else + { + memcpy(&dev->new_servers[dev->new_servers_num].host, &msg->host, sizeof(msg->host)); + dev->new_servers[dev->new_servers_num].failures = (cmd == IOCTL_ADD_SRV ? 0 : 1); // 0 = ADD, 1 = REM + ++dev->new_servers_num; + result = 0; + } + break; + + case BLKFLSBUF: + result = 0; + break; + + default: + result = -EIO; + break; + } + +cleanup_return: + if (msg) kfree(msg); + if (imgname) kfree(imgname); + return result; + +} + +static const struct block_device_operations dnbd3_fops = +{ + .owner = THIS_MODULE, + .open = dnbd3_open, + .release = dnbd3_release, + .ioctl = dnbd3_ioctl, + .compat_ioctl = dnbd3_ioctl, +}; + +static blk_status_t dnbd3_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_queue_rq"); + return 0; +} + +static void dnbd3_complete_rq(struct request *req) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_complete_rq"); + +} + +static int dnbd3_init_request(struct blk_mq_tag_set *set, struct request *rq, unsigned int hctx_idx, unsigned int numa_node) +{ + struct dnbd3_cmd *cmd = blk_mq_rq_to_pdu(rq); + cmd->dnbd3 = set->driver_data; + cmd->flags = 0; + mutex_init(&cmd->lock); + return 0; +} +static enum blk_eh_timer_return dnbd3_xmit_timeout(struct request *req, bool reserved) +{ + printk(KERN_DEBUG "dnbd3: dnbd3_xmit_timeout"); + return BLK_EH_DONE; +} + + +static const struct blk_mq_ops dnbd3_mq_ops = { + .queue_rq = dnbd3_queue_rq, + .complete = dnbd3_complete_rq, + .init_request = dnbd3_init_request, + .timeout = dnbd3_xmit_timeout, +}; + + +static int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor) +{ + struct gendisk *disk; + struct request_queue *q; + int err = -ENOMEM; + printk(KERN_DEBUG "dnbd3: adding device %i", minor); + + + disk = alloc_disk(1); + if (!disk) { + printk(KERN_DEBUG "dnbd3: alloc_disc failed, device %i", minor); + goto out_free_nbd; + } + + err = idr_alloc(&dnbd3_index_idr, dev, minor, minor + 1, GFP_KERNEL); + if (err == -ENOSPC) { + printk(KERN_DEBUG "dnbd3: idr_alloc failed, device %i", minor); + err = -EEXIST; + } + + if (err < 0) + goto out_free_disk; + + dev->minor = minor; + dev->disk = disk; + dev->tag_set.ops = &dnbd3_mq_ops; + dev->tag_set.nr_hw_queues = 1; + dev->tag_set.queue_depth = 128; + dev->tag_set.numa_node = NUMA_NO_NODE; + dev->tag_set.cmd_size = sizeof(dnbd3_cmd); + dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | + BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; + dev->tag_set.driver_data = dev; + + err = blk_mq_alloc_tag_set(&dev->tag_set); + if (err) + goto out_free_idr; + + q = blk_mq_init_queue(&dev->tag_set); + if (IS_ERR(q)) { + err = PTR_ERR(q); + goto out_free_tags; + } + disk->queue = q; + + /* + * Tell the block layer that we are not a rotational device + */ + blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); + disk->queue->limits.discard_granularity = 0; + disk->queue->limits.discard_alignment = 0; + blk_queue_max_discard_sectors(disk->queue, 0); + blk_queue_max_segment_size(disk->queue, UINT_MAX); + blk_queue_max_segments(disk->queue, USHRT_MAX); + blk_queue_max_hw_sectors(disk->queue, 65536); + disk->queue->limits.max_sectors = 256; + + mutex_init(&dev->config_lock); + refcount_set(&dev->config_refs, 0); + refcount_set(&dev->refs, 1); + INIT_LIST_HEAD(&dev->list); + disk->major = major; + disk->first_minor = minor; + disk->fops = &dnbd3_fops; + disk->private_data = dev; + sprintf(disk->disk_name, "dnbd%d", minor); +// sprintf(disk->disk_name, "dnbd3%d", minor); + printk(KERN_DEBUG "dnbd3: add disk, device %s", disk->disk_name); + add_disk(disk); + dnbd3_sysfs_init(dev); + return minor; + +out_free_tags: + blk_mq_free_tag_set(&dev->tag_set); +out_free_idr: + idr_remove(&dnbd3_index_idr, minor); +out_free_disk: + put_disk(disk); +out_free_nbd: + kfree(dev); + printk(KERN_DEBUG "dnbd3: destroy device %i", minor); + return err; +} + + + +static int __init dnbd3_init(void) +{ + int i; + printk(KERN_DEBUG "dnbd3: starting kernel module"); + + if (max_devs < 0) { + printk(KERN_ERR "dnbd3: max_devs must be >= 0"); + return -EINVAL; + } + + + dnbd3_device = kcalloc(max_devs, sizeof(*dnbd3_device), GFP_KERNEL); + if (!dnbd3_device) { + printk(KERN_ERR "dnbd3: failed to create dnbd3 device"); + return -ENOMEM; + } + + // initialize block device + major = register_blkdev(0, "dnbd3"); + if (major == 0) { + printk(KERN_ERR "dnbd3: register_blkdev failed"); + return -EIO; + } + + printk(KERN_DEBUG "dnbd3: kernel module loaded. Machine type: " ENDIAN_MODE); + + // add MAX_NUMBER_DEVICES devices + mutex_lock(&dnbd3_index_mutex); + for (i = 0; i < max_devs; i++) { + dnbd3_blk_add_device(&dnbd3_device[i], i); + } + mutex_unlock(&dnbd3_index_mutex); + + printk(KERN_INFO "dnbd3: init successful (%i devices).\n", max_devs); + + return 0; +} + + +static int dnbd3_exit_cb(int id, void *ptr, void *data) +{ + struct list_head *list = (struct list_head *)data; + struct dnbd3_device_t *dnbd3 = ptr; + + list_add_tail(&dnbd3->list, list); + return 0; +} + +static void dnbd3_dev_remove(struct dnbd3_device_t *dnbd3) +{ + struct gendisk *disk = dnbd3->disk; + struct request_queue *q; + + if (disk) { + q = disk->queue; + del_gendisk(disk); + blk_cleanup_queue(q); + blk_mq_free_tag_set(&dnbd3->tag_set); + disk->private_data = NULL; + put_disk(disk); + } +} + +static void dnbd3_put(struct dnbd3_device_t *dnbd3) +{ + if (refcount_dec_and_mutex_lock(&dnbd3->refs, &dnbd3_index_mutex)) { + idr_remove(&dnbd3_index_idr, dnbd3->minor); + mutex_unlock(&dnbd3_index_mutex); + dnbd3_dev_remove(dnbd3); + } +} + + +static void __exit dnbd3_exit(void) +{ + dnbd3_device_t *dnbd3; + LIST_HEAD(del_list); + printk(KERN_DEBUG "dnbd3: stopping kernel module"); + + mutex_lock(&dnbd3_index_mutex); + idr_for_each(&dnbd3_index_idr, &dnbd3_exit_cb, &del_list); + mutex_unlock(&dnbd3_index_mutex); + + while (!list_empty(&del_list)) { + dnbd3 = list_first_entry(&del_list, struct dnbd3_device_t, list); + dnbd3_sysfs_exit(dnbd3); + list_del_init(&dnbd3->list); + if (refcount_read(&dnbd3->refs) != 1) { + printk(KERN_ERR "dnbd3: possibly leaking a device\n"); + } + dnbd3_put(dnbd3); + } + + idr_destroy(&dnbd3_index_idr); + unregister_blkdev(major, "dnbd3"); + + kfree(dnbd3_device); + + printk(KERN_INFO "dnbd3: stopped kernel module"); +} + + +module_init(dnbd3_init); +module_exit(dnbd3_exit); + +MODULE_DESCRIPTION("Distributed Network Block Device 3"); +MODULE_LICENSE("GPL"); + +module_param(max_devs, int, 0444); +MODULE_PARM_DESC(max_devs, "number of network block devices to initialize (default: 8)"); -- cgit v1.2.3-55-g7522