+++ /dev/null
-
-/*
- osdblk.c -- Export a single SCSI OSD object as a Linux block device
-
-
- Copyright 2009 Red Hat, Inc.
-
- 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.
-
- 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; see the file COPYING. If not, write to
- the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
-
-
- Instructions for use
- --------------------
-
- 1) Map a Linux block device to an existing OSD object.
-
- In this example, we will use partition id 1234, object id 5678,
- OSD device /dev/osd1.
-
- $ echo "1234 5678 /dev/osd1" > /sys/class/osdblk/add
-
-
- 2) List all active blkdev<->object mappings.
-
- In this example, we have performed step #1 twice, creating two blkdevs,
- mapped to two separate OSD objects.
-
- $ cat /sys/class/osdblk/list
- 0 174 1234 5678 /dev/osd1
- 1 179 1994 897123 /dev/osd0
-
- The columns, in order, are:
- - blkdev unique id
- - blkdev assigned major
- - OSD object partition id
- - OSD object id
- - OSD device
-
-
- 3) Remove an active blkdev<->object mapping.
-
- In this example, we remove the mapping with blkdev unique id 1.
-
- $ echo 1 > /sys/class/osdblk/remove
-
-
- NOTE: The actual creation and deletion of OSD objects is outside the scope
- of this driver.
-
- */
-
-#include <linux/kernel.h>
-#include <linux/device.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/slab.h>
-#include <scsi/osd_initiator.h>
-#include <scsi/osd_attributes.h>
-#include <scsi/osd_sec.h>
-#include <scsi/scsi_device.h>
-
-#define DRV_NAME "osdblk"
-#define PFX DRV_NAME ": "
-
-/* #define _OSDBLK_DEBUG */
-#ifdef _OSDBLK_DEBUG
-#define OSDBLK_DEBUG(fmt, a...) \
- printk(KERN_NOTICE "osdblk @%s:%d: " fmt, __func__, __LINE__, ##a)
-#else
-#define OSDBLK_DEBUG(fmt, a...) \
- do { if (0) printk(fmt, ##a); } while (0)
-#endif
-
-MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
-MODULE_DESCRIPTION("block device inside an OSD object osdblk.ko");
-MODULE_LICENSE("GPL");
-
-struct osdblk_device;
-
-enum {
- OSDBLK_MINORS_PER_MAJOR = 256, /* max minors per blkdev */
- OSDBLK_MAX_REQ = 32, /* max parallel requests */
- OSDBLK_OP_TIMEOUT = 4 * 60, /* sync OSD req timeout */
-};
-
-struct osdblk_request {
- struct request *rq; /* blk layer request */
- struct bio *bio; /* cloned bio */
- struct osdblk_device *osdev; /* associated blkdev */
-};
-
-struct osdblk_device {
- int id; /* blkdev unique id */
-
- int major; /* blkdev assigned major */
- struct gendisk *disk; /* blkdev's gendisk and rq */
- struct request_queue *q;
-
- struct osd_dev *osd; /* associated OSD */
-
- char name[32]; /* blkdev name, e.g. osdblk34 */
-
- spinlock_t lock; /* queue lock */
-
- struct osd_obj_id obj; /* OSD partition, obj id */
- uint8_t obj_cred[OSD_CAP_LEN]; /* OSD cred */
-
- struct osdblk_request req[OSDBLK_MAX_REQ]; /* request table */
-
- struct list_head node;
-
- char osd_path[0]; /* OSD device path */
-};
-
-static struct class *class_osdblk; /* /sys/class/osdblk */
-static DEFINE_MUTEX(ctl_mutex); /* Serialize open/close/setup/teardown */
-static LIST_HEAD(osdblkdev_list);
-
-static const struct block_device_operations osdblk_bd_ops = {
- .owner = THIS_MODULE,
-};
-
-static const struct osd_attr g_attr_logical_length = ATTR_DEF(
- OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
-
-static void osdblk_make_credential(u8 cred_a[OSD_CAP_LEN],
- const struct osd_obj_id *obj)
-{
- osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
-}
-
-/* copied from exofs; move to libosd? */
-/*
- * Perform a synchronous OSD operation. copied from exofs; move to libosd?
- */
-static int osd_sync_op(struct osd_request *or, int timeout, uint8_t *credential)
-{
- int ret;
-
- or->timeout = timeout;
- ret = osd_finalize_request(or, 0, credential, NULL);
- if (ret)
- return ret;
-
- ret = osd_execute_request(or);
-
- /* osd_req_decode_sense(or, ret); */
- return ret;
-}
-
-/*
- * Perform an asynchronous OSD operation. copied from exofs; move to libosd?
- */
-static int osd_async_op(struct osd_request *or, osd_req_done_fn *async_done,
- void *caller_context, u8 *cred)
-{
- int ret;
-
- ret = osd_finalize_request(or, 0, cred, NULL);
- if (ret)
- return ret;
-
- ret = osd_execute_request_async(or, async_done, caller_context);
-
- return ret;
-}
-
-/* copied from exofs; move to libosd? */
-static int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr)
-{
- struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
- void *iter = NULL;
- int nelem;
-
- do {
- nelem = 1;
- osd_req_decode_get_attr_list(or, &cur_attr, &nelem, &iter);
- if ((cur_attr.attr_page == attr->attr_page) &&
- (cur_attr.attr_id == attr->attr_id)) {
- attr->len = cur_attr.len;
- attr->val_ptr = cur_attr.val_ptr;
- return 0;
- }
- } while (iter);
-
- return -EIO;
-}
-
-static int osdblk_get_obj_size(struct osdblk_device *osdev, u64 *size_out)
-{
- struct osd_request *or;
- struct osd_attr attr;
- int ret;
-
- /* start request */
- or = osd_start_request(osdev->osd, GFP_KERNEL);
- if (!or)
- return -ENOMEM;
-
- /* create a get-attributes(length) request */
- osd_req_get_attributes(or, &osdev->obj);
-
- osd_req_add_get_attr_list(or, &g_attr_logical_length, 1);
-
- /* execute op synchronously */
- ret = osd_sync_op(or, OSDBLK_OP_TIMEOUT, osdev->obj_cred);
- if (ret)
- goto out;
-
- /* extract length from returned attribute info */
- attr = g_attr_logical_length;
- ret = extract_attr_from_req(or, &attr);
- if (ret)
- goto out;
-
- *size_out = get_unaligned_be64(attr.val_ptr);
-
-out:
- osd_end_request(or);
- return ret;
-
-}
-
-static void osdblk_osd_complete(struct osd_request *or, void *private)
-{
- struct osdblk_request *orq = private;
- struct osd_sense_info osi;
- int ret = osd_req_decode_sense(or, &osi);
-
- if (ret) {
- ret = -EIO;
- OSDBLK_DEBUG("osdblk_osd_complete with err=%d\n", ret);
- }
-
- /* complete OSD request */
- osd_end_request(or);
-
- /* complete request passed to osdblk by block layer */
- __blk_end_request_all(orq->rq, ret);
-}
-
-static void bio_chain_put(struct bio *chain)
-{
- struct bio *tmp;
-
- while (chain) {
- tmp = chain;
- chain = chain->bi_next;
-
- bio_put(tmp);
- }
-}
-
-static struct bio *bio_chain_clone(struct bio *old_chain, gfp_t gfpmask)
-{
- struct bio *tmp, *new_chain = NULL, *tail = NULL;
-
- while (old_chain) {
- tmp = bio_clone_kmalloc(old_chain, gfpmask);
- if (!tmp)
- goto err_out;
-
- tmp->bi_bdev = NULL;
- gfpmask &= ~__GFP_DIRECT_RECLAIM;
- tmp->bi_next = NULL;
-
- if (!new_chain)
- new_chain = tail = tmp;
- else {
- tail->bi_next = tmp;
- tail = tmp;
- }
-
- old_chain = old_chain->bi_next;
- }
-
- return new_chain;
-
-err_out:
- OSDBLK_DEBUG("bio_chain_clone with err\n");
- bio_chain_put(new_chain);
- return NULL;
-}
-
-static void osdblk_rq_fn(struct request_queue *q)
-{
- struct osdblk_device *osdev = q->queuedata;
-
- while (1) {
- struct request *rq;
- struct osdblk_request *orq;
- struct osd_request *or;
- struct bio *bio;
- bool do_write, do_flush;
-
- /* peek at request from block layer */
- rq = blk_fetch_request(q);
- if (!rq)
- break;
-
- /* deduce our operation (read, write, flush) */
- /* I wish the block layer simplified cmd_type/cmd_flags/cmd[]
- * into a clearly defined set of RPC commands:
- * read, write, flush, scsi command, power mgmt req,
- * driver-specific, etc.
- */
-
- do_flush = (req_op(rq) == REQ_OP_FLUSH);
- do_write = (rq_data_dir(rq) == WRITE);
-
- if (!do_flush) { /* osd_flush does not use a bio */
- /* a bio clone to be passed down to OSD request */
- bio = bio_chain_clone(rq->bio, GFP_ATOMIC);
- if (!bio)
- break;
- } else
- bio = NULL;
-
- /* alloc internal OSD request, for OSD command execution */
- or = osd_start_request(osdev->osd, GFP_ATOMIC);
- if (!or) {
- bio_chain_put(bio);
- OSDBLK_DEBUG("osd_start_request with err\n");
- break;
- }
-
- orq = &osdev->req[rq->tag];
- orq->rq = rq;
- orq->bio = bio;
- orq->osdev = osdev;
-
- /* init OSD command: flush, write or read */
- if (do_flush)
- osd_req_flush_object(or, &osdev->obj,
- OSD_CDB_FLUSH_ALL, 0, 0);
- else if (do_write)
- osd_req_write(or, &osdev->obj, blk_rq_pos(rq) * 512ULL,
- bio, blk_rq_bytes(rq));
- else
- osd_req_read(or, &osdev->obj, blk_rq_pos(rq) * 512ULL,
- bio, blk_rq_bytes(rq));
-
- OSDBLK_DEBUG("%s 0x%x bytes at 0x%llx\n",
- do_flush ? "flush" : do_write ?
- "write" : "read", blk_rq_bytes(rq),
- blk_rq_pos(rq) * 512ULL);
-
- /* begin OSD command execution */
- if (osd_async_op(or, osdblk_osd_complete, orq,
- osdev->obj_cred)) {
- osd_end_request(or);
- blk_requeue_request(q, rq);
- bio_chain_put(bio);
- OSDBLK_DEBUG("osd_execute_request_async with err\n");
- break;
- }
-
- /* remove the special 'flush' marker, now that the command
- * is executing
- */
- rq->special = NULL;
- }
-}
-
-static void osdblk_free_disk(struct osdblk_device *osdev)
-{
- struct gendisk *disk = osdev->disk;
-
- if (!disk)
- return;
-
- if (disk->flags & GENHD_FL_UP)
- del_gendisk(disk);
- if (disk->queue)
- blk_cleanup_queue(disk->queue);
- put_disk(disk);
-}
-
-static int osdblk_init_disk(struct osdblk_device *osdev)
-{
- struct gendisk *disk;
- struct request_queue *q;
- int rc;
- u64 obj_size = 0;
-
- /* contact OSD, request size info about the object being mapped */
- rc = osdblk_get_obj_size(osdev, &obj_size);
- if (rc)
- return rc;
-
- /* create gendisk info */
- disk = alloc_disk(OSDBLK_MINORS_PER_MAJOR);
- if (!disk)
- return -ENOMEM;
-
- sprintf(disk->disk_name, DRV_NAME "%d", osdev->id);
- disk->major = osdev->major;
- disk->first_minor = 0;
- disk->fops = &osdblk_bd_ops;
- disk->private_data = osdev;
-
- /* init rq */
- q = blk_init_queue(osdblk_rq_fn, &osdev->lock);
- if (!q) {
- put_disk(disk);
- return -ENOMEM;
- }
-
- /* switch queue to TCQ mode; allocate tag map */
- rc = blk_queue_init_tags(q, OSDBLK_MAX_REQ, NULL, BLK_TAG_ALLOC_FIFO);
- if (rc) {
- blk_cleanup_queue(q);
- put_disk(disk);
- return rc;
- }
-
- /* Set our limits to the lower device limits, because osdblk cannot
- * sleep when allocating a lower-request and therefore cannot be
- * bouncing.
- */
- blk_queue_stack_limits(q, osd_request_queue(osdev->osd));
-
- blk_queue_prep_rq(q, blk_queue_start_tag);
- blk_queue_write_cache(q, true, false);
-
- disk->queue = q;
-
- q->queuedata = osdev;
-
- osdev->disk = disk;
- osdev->q = q;
-
- /* finally, announce the disk to the world */
- set_capacity(disk, obj_size / 512ULL);
- add_disk(disk);
-
- printk(KERN_INFO "%s: Added of size 0x%llx\n",
- disk->disk_name, (unsigned long long)obj_size);
-
- return 0;
-}
-
-/********************************************************************
- * /sys/class/osdblk/
- * add map OSD object to blkdev
- * remove unmap OSD object
- * list show mappings
- *******************************************************************/
-
-static void class_osdblk_release(struct class *cls)
-{
- kfree(cls);
-}
-
-static ssize_t class_osdblk_list(struct class *c,
- struct class_attribute *attr,
- char *data)
-{
- int n = 0;
- struct list_head *tmp;
-
- mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-
- list_for_each(tmp, &osdblkdev_list) {
- struct osdblk_device *osdev;
-
- osdev = list_entry(tmp, struct osdblk_device, node);
-
- n += sprintf(data+n, "%d %d %llu %llu %s\n",
- osdev->id,
- osdev->major,
- osdev->obj.partition,
- osdev->obj.id,
- osdev->osd_path);
- }
-
- mutex_unlock(&ctl_mutex);
- return n;
-}
-
-static ssize_t class_osdblk_add(struct class *c,
- struct class_attribute *attr,
- const char *buf, size_t count)
-{
- struct osdblk_device *osdev;
- ssize_t rc;
- int irc, new_id = 0;
- struct list_head *tmp;
-
- if (!try_module_get(THIS_MODULE))
- return -ENODEV;
-
- /* new osdblk_device object */
- osdev = kzalloc(sizeof(*osdev) + strlen(buf) + 1, GFP_KERNEL);
- if (!osdev) {
- rc = -ENOMEM;
- goto err_out_mod;
- }
-
- /* static osdblk_device initialization */
- spin_lock_init(&osdev->lock);
- INIT_LIST_HEAD(&osdev->node);
-
- /* generate unique id: find highest unique id, add one */
-
- mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-
- list_for_each(tmp, &osdblkdev_list) {
- struct osdblk_device *osdev;
-
- osdev = list_entry(tmp, struct osdblk_device, node);
- if (osdev->id > new_id)
- new_id = osdev->id + 1;
- }
-
- osdev->id = new_id;
-
- /* add to global list */
- list_add_tail(&osdev->node, &osdblkdev_list);
-
- mutex_unlock(&ctl_mutex);
-
- /* parse add command */
- if (sscanf(buf, "%llu %llu %s", &osdev->obj.partition, &osdev->obj.id,
- osdev->osd_path) != 3) {
- rc = -EINVAL;
- goto err_out_slot;
- }
-
- /* initialize rest of new object */
- sprintf(osdev->name, DRV_NAME "%d", osdev->id);
-
- /* contact requested OSD */
- osdev->osd = osduld_path_lookup(osdev->osd_path);
- if (IS_ERR(osdev->osd)) {
- rc = PTR_ERR(osdev->osd);
- goto err_out_slot;
- }
-
- /* build OSD credential */
- osdblk_make_credential(osdev->obj_cred, &osdev->obj);
-
- /* register our block device */
- irc = register_blkdev(0, osdev->name);
- if (irc < 0) {
- rc = irc;
- goto err_out_osd;
- }
-
- osdev->major = irc;
-
- /* set up and announce blkdev mapping */
- rc = osdblk_init_disk(osdev);
- if (rc)
- goto err_out_blkdev;
-
- return count;
-
-err_out_blkdev:
- unregister_blkdev(osdev->major, osdev->name);
-err_out_osd:
- osduld_put_device(osdev->osd);
-err_out_slot:
- mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
- list_del_init(&osdev->node);
- mutex_unlock(&ctl_mutex);
-
- kfree(osdev);
-err_out_mod:
- OSDBLK_DEBUG("Error adding device %s\n", buf);
- module_put(THIS_MODULE);
- return rc;
-}
-
-static ssize_t class_osdblk_remove(struct class *c,
- struct class_attribute *attr,
- const char *buf,
- size_t count)
-{
- struct osdblk_device *osdev = NULL;
- int target_id, rc;
- unsigned long ul;
- struct list_head *tmp;
-
- rc = kstrtoul(buf, 10, &ul);
- if (rc)
- return rc;
-
- /* convert to int; abort if we lost anything in the conversion */
- target_id = (int) ul;
- if (target_id != ul)
- return -EINVAL;
-
- /* remove object from list immediately */
- mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-
- list_for_each(tmp, &osdblkdev_list) {
- osdev = list_entry(tmp, struct osdblk_device, node);
- if (osdev->id == target_id) {
- list_del_init(&osdev->node);
- break;
- }
- osdev = NULL;
- }
-
- mutex_unlock(&ctl_mutex);
-
- if (!osdev)
- return -ENOENT;
-
- /* clean up and free blkdev and associated OSD connection */
- osdblk_free_disk(osdev);
- unregister_blkdev(osdev->major, osdev->name);
- osduld_put_device(osdev->osd);
- kfree(osdev);
-
- /* release module ref */
- module_put(THIS_MODULE);
-
- return count;
-}
-
-static struct class_attribute class_osdblk_attrs[] = {
- __ATTR(add, 0200, NULL, class_osdblk_add),
- __ATTR(remove, 0200, NULL, class_osdblk_remove),
- __ATTR(list, 0444, class_osdblk_list, NULL),
- __ATTR_NULL
-};
-
-static int osdblk_sysfs_init(void)
-{
- int ret = 0;
-
- /*
- * create control files in sysfs
- * /sys/class/osdblk/...
- */
- class_osdblk = kzalloc(sizeof(*class_osdblk), GFP_KERNEL);
- if (!class_osdblk)
- return -ENOMEM;
-
- class_osdblk->name = DRV_NAME;
- class_osdblk->owner = THIS_MODULE;
- class_osdblk->class_release = class_osdblk_release;
- class_osdblk->class_attrs = class_osdblk_attrs;
-
- ret = class_register(class_osdblk);
- if (ret) {
- kfree(class_osdblk);
- class_osdblk = NULL;
- printk(PFX "failed to create class osdblk\n");
- return ret;
- }
-
- return 0;
-}
-
-static void osdblk_sysfs_cleanup(void)
-{
- if (class_osdblk)
- class_destroy(class_osdblk);
- class_osdblk = NULL;
-}
-
-static int __init osdblk_init(void)
-{
- int rc;
-
- rc = osdblk_sysfs_init();
- if (rc)
- return rc;
-
- return 0;
-}
-
-static void __exit osdblk_exit(void)
-{
- osdblk_sysfs_cleanup();
-}
-
-module_init(osdblk_init);
-module_exit(osdblk_exit);
-
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