// SPDX-License-Identifier: GPL-2.0-or-later/* * Interface to Linux block layer for MTD 'translation layers'. * * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org> */ #include <linux/kernel.h>#include <linux/slab.h>#include <linux/module.h>#include <linux/list.h>#include <linux/fs.h>#include <linux/mtd/blktrans.h>#include <linux/mtd/mtd.h>#include <linux/blkdev.h>#include <linux/blk-mq.h>#include <linux/blkpg.h>#include <linux/spinlock.h>#include <linux/hdreg.h>#include <linux/mutex.h>#include <linux/uaccess.h> #include "mtdcore.h" static LIST_HEAD(blktrans_majors); static void blktrans_dev_release(struct kref *kref){ struct mtd_blktrans_dev *dev = container_of(kref, struct mtd_blktrans_dev, ref); put_disk(dev->disk); blk_mq_free_tag_set(dev->tag_set); kfree(dev->tag_set); list_del(&dev->list); kfree(dev);} static void blktrans_dev_put(struct mtd_blktrans_dev *dev){ kref_put(&dev->ref, blktrans_dev_release);} static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr, struct mtd_blktrans_dev *dev, struct request *req){ struct req_iterator iter; struct bio_vec bvec; unsigned long block, nsect; char *buf; block = blk_rq_pos(req) << 9 >> tr->blkshift; nsect = blk_rq_cur_bytes(req) >> tr->blkshift; switch (req_op(req)) { case REQ_OP_FLUSH: if (tr->flush(dev)) return BLK_STS_IOERR; return BLK_STS_OK; case REQ_OP_DISCARD: if (tr->discard(dev, block, nsect)) return BLK_STS_IOERR; return BLK_STS_OK; case REQ_OP_READ: buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); for (; nsect > 0; nsect--, block++, buf += tr->blksize) { if (tr->readsect(dev, block, buf)) { kunmap(bio_page(req->bio)); return BLK_STS_IOERR; } } kunmap(bio_page(req->bio)); rq_for_each_segment(bvec, req, iter) flush_dcache_page(bvec.bv_page); return BLK_STS_OK; case REQ_OP_WRITE: if (!tr->writesect) return BLK_STS_IOERR; rq_for_each_segment(bvec, req, iter) flush_dcache_page(bvec.bv_page); buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); for (; nsect > 0; nsect--, block++, buf += tr->blksize) { if (tr->writesect(dev, block, buf)) { kunmap(bio_page(req->bio)); return BLK_STS_IOERR; } } kunmap(bio_page(req->bio)); return BLK_STS_OK; default: return BLK_STS_IOERR; }} int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev){ return dev->bg_stop;}EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); static struct request *mtd_next_request(struct mtd_blktrans_dev *dev){ struct request *rq; rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist); if (rq) { list_del_init(&rq->queuelist); blk_mq_start_request(rq); return rq; } return NULL;} static void mtd_blktrans_work(struct mtd_blktrans_dev *dev) __releases(&dev->queue_lock) __acquires(&dev->queue_lock){ struct mtd_blktrans_ops *tr = dev->tr; struct request *req = NULL; int background_done = 0; while (1) { blk_status_t res; dev->bg_stop = false; if (!req && !(req = mtd_next_request(dev))) { if (tr->background && !background_done) { spin_unlock_irq(&dev->queue_lock); mutex_lock(&dev->lock); tr->background(dev); mutex_unlock(&dev->lock); spin_lock_irq(&dev->queue_lock); /* * Do background processing just once per idle * period. */ background_done = !dev->bg_stop; continue; } break; } spin_unlock_irq(&dev->queue_lock); mutex_lock(&dev->lock); res = do_blktrans_request(dev->tr, dev, req); mutex_unlock(&dev->lock); if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) { __blk_mq_end_request(req, res); req = NULL; } background_done = 0; cond_resched(); spin_lock_irq(&dev->queue_lock); }} static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd){ struct mtd_blktrans_dev *dev; dev = hctx->queue->queuedata; if (!dev) { blk_mq_start_request(bd->rq); return BLK_STS_IOERR; } spin_lock_irq(&dev->queue_lock); list_add_tail(&bd->rq->queuelist, &dev->rq_list); mtd_blktrans_work(dev); spin_unlock_irq(&dev->queue_lock); return BLK_STS_OK;} static int blktrans_open(struct gendisk *disk, blk_mode_t mode){ struct mtd_blktrans_dev *dev = disk->private_data; int ret = 0; kref_get(&dev->ref); mutex_lock(&dev->lock); if (dev->open) goto unlock; __module_get(dev->tr->owner); if (!dev->mtd) goto unlock; if (dev->tr->open) { ret = dev->tr->open(dev); if (ret) goto error_put; } ret = __get_mtd_device(dev->mtd); if (ret) goto error_release; dev->writable = mode & BLK_OPEN_WRITE; unlock: dev->open++; mutex_unlock(&dev->lock); return ret; error_release: if (dev->tr->release) dev->tr->release(dev);error_put: module_put(dev->tr->owner); mutex_unlock(&dev->lock); blktrans_dev_put(dev); return ret;} static void blktrans_release(struct gendisk *disk){ struct mtd_blktrans_dev *dev = disk->private_data; mutex_lock(&dev->lock); if (--dev->open) goto unlock; module_put(dev->tr->owner); if (dev->mtd) { if (dev->tr->release) dev->tr->release(dev); __put_mtd_device(dev->mtd); }unlock: mutex_unlock(&dev->lock); blktrans_dev_put(dev);} static int blktrans_getgeo(struct gendisk *disk, struct hd_geometry *geo){ struct mtd_blktrans_dev *dev = disk->private_data; int ret = -ENXIO; mutex_lock(&dev->lock); if (!dev->mtd) goto unlock; ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;unlock: mutex_unlock(&dev->lock); return ret;} static const struct block_device_operations mtd_block_ops = { .owner = THIS_MODULE, .open = blktrans_open, .release = blktrans_release, .getgeo = blktrans_getgeo,}; static const struct blk_mq_ops mtd_mq_ops = { .queue_rq = mtd_queue_rq,}; int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new){ struct mtd_blktrans_ops *tr = new->tr; struct mtd_blktrans_dev *d; struct queue_limits lim = { }; int last_devnum = -1; struct gendisk *gd; int ret; lockdep_assert_held(&mtd_table_mutex); list_for_each_entry(d, &tr->devs, list) { if (new->devnum == -1) { /* Use first free number */ if (d->devnum != last_devnum+1) { /* Found a free devnum. Plug it in here */ new->devnum = last_devnum+1; list_add_tail(&new->list, &d->list); goto added; } } else if (d->devnum == new->devnum) { /* Required number taken */ return -EBUSY; } else if (d->devnum > new->devnum) { /* Required number was free */ list_add_tail(&new->list, &d->list); goto added; } last_devnum = d->devnum; } ret = -EBUSY; if (new->devnum == -1) new->devnum = last_devnum+1; /* Check that the device and any partitions will get valid * minor numbers and that the disk naming code below can cope * with this number. */ if (new->devnum > (MINORMASK >> tr->part_bits) || (tr->part_bits && new->devnum >= 27 * 26)) return ret; list_add_tail(&new->list, &tr->devs); added: mutex_init(&new->lock); kref_init(&new->ref); if (!tr->writesect) new->readonly = 1; ret = -ENOMEM; new->tag_set = kzalloc_obj(*new->tag_set); if (!new->tag_set) goto out_list_del; ret = blk_mq_alloc_sq_tag_set(new->tag_set, &mtd_mq_ops, 2, BLK_MQ_F_BLOCKING); if (ret) goto out_kfree_tag_set; lim.logical_block_size = tr->blksize; if (tr->discard) lim.max_hw_discard_sectors = UINT_MAX; if (tr->flush) lim.features |= BLK_FEAT_WRITE_CACHE; /* Create gendisk */ gd = blk_mq_alloc_disk(new->tag_set, &lim, new); if (IS_ERR(gd)) { ret = PTR_ERR(gd); goto out_free_tag_set; } new->disk = gd; new->rq = new->disk->queue; gd->private_data = new; gd->major = tr->major; gd->first_minor = (new->devnum) << tr->part_bits; gd->minors = 1 << tr->part_bits; gd->fops = &mtd_block_ops; if (tr->part_bits) { if (new->devnum < 26) snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%c", tr->name, 'a' + new->devnum); else snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%c%c", tr->name, 'a' - 1 + new->devnum / 26, 'a' + new->devnum % 26); } else { snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%d", tr->name, new->devnum); gd->flags |= GENHD_FL_NO_PART; } set_capacity(gd, ((u64)new->size * tr->blksize) >> 9); /* Create the request queue */ spin_lock_init(&new->queue_lock); INIT_LIST_HEAD(&new->rq_list); gd->queue = new->rq; if (new->readonly) set_disk_ro(gd, 1); ret = device_add_disk(&new->mtd->dev, gd, NULL); if (ret) goto out_cleanup_disk; if (new->disk_attributes) { ret = sysfs_create_group(&disk_to_dev(gd)->kobj, new->disk_attributes); WARN_ON(ret); } return 0; out_cleanup_disk: put_disk(new->disk);out_free_tag_set: blk_mq_free_tag_set(new->tag_set);out_kfree_tag_set: kfree(new->tag_set);out_list_del: list_del(&new->list); return ret;} int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old){ unsigned long flags; unsigned int memflags; lockdep_assert_held(&mtd_table_mutex); if (old->disk_attributes) sysfs_remove_group(&disk_to_dev(old->disk)->kobj, old->disk_attributes); /* Stop new requests to arrive */ del_gendisk(old->disk); /* Kill current requests */ spin_lock_irqsave(&old->queue_lock, flags); old->rq->queuedata = NULL; spin_unlock_irqrestore(&old->queue_lock, flags); /* freeze+quiesce queue to ensure all requests are flushed */ memflags = blk_mq_freeze_queue(old->rq); blk_mq_quiesce_queue(old->rq); blk_mq_unquiesce_queue(old->rq); blk_mq_unfreeze_queue(old->rq, memflags); /* If the device is currently open, tell trans driver to close it, then put mtd device, and don't touch it again */ mutex_lock(&old->lock); if (old->open) { if (old->tr->release) old->tr->release(old); __put_mtd_device(old->mtd); } old->mtd = NULL; mutex_unlock(&old->lock); blktrans_dev_put(old); return 0;} static void blktrans_notify_remove(struct mtd_info *mtd){ struct mtd_blktrans_ops *tr; struct mtd_blktrans_dev *dev, *next; list_for_each_entry(tr, &blktrans_majors, list) list_for_each_entry_safe(dev, next, &tr->devs, list) if (dev->mtd == mtd) tr->remove_dev(dev);} static void blktrans_notify_add(struct mtd_info *mtd){ struct mtd_blktrans_ops *tr; if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME) return; list_for_each_entry(tr, &blktrans_majors, list) tr->add_mtd(tr, mtd);} static struct mtd_notifier blktrans_notifier = { .add = blktrans_notify_add, .remove = blktrans_notify_remove,}; int register_mtd_blktrans(struct mtd_blktrans_ops *tr){ struct mtd_info *mtd; int ret; /* Register the notifier if/when the first device type is registered, to prevent the link/init ordering from fucking us over. */ if (!blktrans_notifier.list.next) register_mtd_user(&blktrans_notifier); ret = register_blkdev(tr->major, tr->name); if (ret < 0) { printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", tr->name, tr->major, ret); return ret; } if (ret) tr->major = ret; tr->blkshift = ffs(tr->blksize) - 1; INIT_LIST_HEAD(&tr->devs); mutex_lock(&mtd_table_mutex); list_add(&tr->list, &blktrans_majors); mtd_for_each_device(mtd) if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)Lines 1–500 of 542. 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// SPDX-License-Identifier: GPL-2.0-or-later /* * Interface to Linux block layer for MTD 'translation layers'. * * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org> */ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/list.h> #include <linux/fs.h> #include <linux/mtd/blktrans.h> #include <linux/mtd/mtd.h> #include <linux/blkdev.h> #include <linux/blk-mq.h> #include <linux/blkpg.h> #include <linux/spinlock.h> #include <linux/hdreg.h> #include <linux/mutex.h> #include <linux/uaccess.h> #include "mtdcore.h" static LIST_HEAD(blktrans_majors); static void blktrans_dev_release(struct kref *kref) { struct mtd_blktrans_dev *dev = container_of(kref, struct mtd_blktrans_dev, ref); put_disk(dev->disk); blk_mq_free_tag_set(dev->tag_set); kfree(dev->tag_set); list_del(&dev->list); kfree(dev); } static void blktrans_dev_put(struct mtd_blktrans_dev *dev) { kref_put(&dev->ref, blktrans_dev_release); } static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr, struct mtd_blktrans_dev *dev, struct request *req) { struct req_iterator iter; struct bio_vec bvec; unsigned long block, nsect; char *buf; block = blk_rq_pos(req) << 9 >> tr->blkshift; nsect = blk_rq_cur_bytes(req) >> tr->blkshift; switch (req_op(req)) { case REQ_OP_FLUSH: if (tr->flush(dev)) return BLK_STS_IOERR; return BLK_STS_OK; case REQ_OP_DISCARD: if (tr->discard(dev, block, nsect)) return BLK_STS_IOERR; return BLK_STS_OK; case REQ_OP_READ: buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); for (; nsect > 0; nsect--, block++, buf += tr->blksize) { if (tr->readsect(dev, block, buf)) { kunmap(bio_page(req->bio)); return BLK_STS_IOERR; } } kunmap(bio_page(req->bio)); rq_for_each_segment(bvec, req, iter) flush_dcache_page(bvec.bv_page); return BLK_STS_OK; case REQ_OP_WRITE: if (!tr->writesect) return BLK_STS_IOERR; rq_for_each_segment(bvec, req, iter) flush_dcache_page(bvec.bv_page); buf = kmap(bio_page(req->bio)) + bio_offset(req->bio); for (; nsect > 0; nsect--, block++, buf += tr->blksize) { if (tr->writesect(dev, block, buf)) { kunmap(bio_page(req->bio)); return BLK_STS_IOERR; } } kunmap(bio_page(req->bio)); return BLK_STS_OK; default: return BLK_STS_IOERR; } } int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) { return dev->bg_stop; } EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); static struct request *mtd_next_request(struct mtd_blktrans_dev *dev) { struct request *rq; rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist); if (rq) { list_del_init(&rq->queuelist); blk_mq_start_request(rq); return rq; } return NULL; } static void mtd_blktrans_work(struct mtd_blktrans_dev *dev) __releases(&dev->queue_lock) __acquires(&dev->queue_lock) { struct mtd_blktrans_ops *tr = dev->tr; struct request *req = NULL; int background_done = 0; while (1) { blk_status_t res; dev->bg_stop = false; if (!req && !(req = mtd_next_request(dev))) { if (tr->background && !background_done) { spin_unlock_irq(&dev->queue_lock); mutex_lock(&dev->lock); tr->background(dev); mutex_unlock(&dev->lock); spin_lock_irq(&dev->queue_lock); /* * Do background processing just once per idle * period. */ background_done = !dev->bg_stop; continue; } break; } spin_unlock_irq(&dev->queue_lock); mutex_lock(&dev->lock); res = do_blktrans_request(dev->tr, dev, req); mutex_unlock(&dev->lock); if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) { __blk_mq_end_request(req, res); req = NULL; } background_done = 0; cond_resched(); spin_lock_irq(&dev->queue_lock); } } static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { struct mtd_blktrans_dev *dev; dev = hctx->queue->queuedata; if (!dev) { blk_mq_start_request(bd->rq); return BLK_STS_IOERR; } spin_lock_irq(&dev->queue_lock); list_add_tail(&bd->rq->queuelist, &dev->rq_list); mtd_blktrans_work(dev); spin_unlock_irq(&dev->queue_lock); return BLK_STS_OK; } static int blktrans_open(struct gendisk *disk, blk_mode_t mode) { struct mtd_blktrans_dev *dev = disk->private_data; int ret = 0; kref_get(&dev->ref); mutex_lock(&dev->lock); if (dev->open) goto unlock; __module_get(dev->tr->owner); if (!dev->mtd) goto unlock; if (dev->tr->open) { ret = dev->tr->open(dev); if (ret) goto error_put; } ret = __get_mtd_device(dev->mtd); if (ret) goto error_release; dev->writable = mode & BLK_OPEN_WRITE; unlock: dev->open++; mutex_unlock(&dev->lock); return ret; error_release: if (dev->tr->release) dev->tr->release(dev); error_put: module_put(dev->tr->owner); mutex_unlock(&dev->lock); blktrans_dev_put(dev); return ret; } static void blktrans_release(struct gendisk *disk) { struct mtd_blktrans_dev *dev = disk->private_data; mutex_lock(&dev->lock); if (--dev->open) goto unlock; module_put(dev->tr->owner); if (dev->mtd) { if (dev->tr->release) dev->tr->release(dev); __put_mtd_device(dev->mtd); } unlock: mutex_unlock(&dev->lock); blktrans_dev_put(dev); } static int blktrans_getgeo(struct gendisk *disk, struct hd_geometry *geo) { struct mtd_blktrans_dev *dev = disk->private_data; int ret = -ENXIO; mutex_lock(&dev->lock); if (!dev->mtd) goto unlock; ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY; unlock: mutex_unlock(&dev->lock); return ret; } static const struct block_device_operations mtd_block_ops = { .owner = THIS_MODULE, .open = blktrans_open, .release = blktrans_release, .getgeo = blktrans_getgeo, }; static const struct blk_mq_ops mtd_mq_ops = { .queue_rq = mtd_queue_rq, }; int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) { struct mtd_blktrans_ops *tr = new->tr; struct mtd_blktrans_dev *d; struct queue_limits lim = { }; int last_devnum = -1; struct gendisk *gd; int ret; lockdep_assert_held(&mtd_table_mutex); list_for_each_entry(d, &tr->devs, list) { if (new->devnum == -1) { /* Use first free number */ if (d->devnum != last_devnum+1) { /* Found a free devnum. Plug it in here */ new->devnum = last_devnum+1; list_add_tail(&new->list, &d->list); goto added; } } else if (d->devnum == new->devnum) { /* Required number taken */ return -EBUSY; } else if (d->devnum > new->devnum) { /* Required number was free */ list_add_tail(&new->list, &d->list); goto added; } last_devnum = d->devnum; } ret = -EBUSY; if (new->devnum == -1) new->devnum = last_devnum+1; /* Check that the device and any partitions will get valid * minor numbers and that the disk naming code below can cope * with this number. */ if (new->devnum > (MINORMASK >> tr->part_bits) || (tr->part_bits && new->devnum >= 27 * 26)) return ret; list_add_tail(&new->list, &tr->devs); added: mutex_init(&new->lock); kref_init(&new->ref); if (!tr->writesect) new->readonly = 1; ret = -ENOMEM; new->tag_set = kzalloc_obj(*new->tag_set); if (!new->tag_set) goto out_list_del; ret = blk_mq_alloc_sq_tag_set(new->tag_set, &mtd_mq_ops, 2, BLK_MQ_F_BLOCKING); if (ret) goto out_kfree_tag_set; lim.logical_block_size = tr->blksize; if (tr->discard) lim.max_hw_discard_sectors = UINT_MAX; if (tr->flush) lim.features |= BLK_FEAT_WRITE_CACHE; /* Create gendisk */ gd = blk_mq_alloc_disk(new->tag_set, &lim, new); if (IS_ERR(gd)) { ret = PTR_ERR(gd); goto out_free_tag_set; } new->disk = gd; new->rq = new->disk->queue; gd->private_data = new; gd->major = tr->major; gd->first_minor = (new->devnum) << tr->part_bits; gd->minors = 1 << tr->part_bits; gd->fops = &mtd_block_ops; if (tr->part_bits) { if (new->devnum < 26) snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%c", tr->name, 'a' + new->devnum); else snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%c%c", tr->name, 'a' - 1 + new->devnum / 26, 'a' + new->devnum % 26); } else { snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%d", tr->name, new->devnum); gd->flags |= GENHD_FL_NO_PART; } set_capacity(gd, ((u64)new->size * tr->blksize) >> 9); /* Create the request queue */ spin_lock_init(&new->queue_lock); INIT_LIST_HEAD(&new->rq_list); gd->queue = new->rq; if (new->readonly) set_disk_ro(gd, 1); ret = device_add_disk(&new->mtd->dev, gd, NULL); if (ret) goto out_cleanup_disk; if (new->disk_attributes) { ret = sysfs_create_group(&disk_to_dev(gd)->kobj, new->disk_attributes); WARN_ON(ret); } return 0; out_cleanup_disk: put_disk(new->disk); out_free_tag_set: blk_mq_free_tag_set(new->tag_set); out_kfree_tag_set: kfree(new->tag_set); out_list_del: list_del(&new->list); return ret; } int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) { unsigned long flags; unsigned int memflags; lockdep_assert_held(&mtd_table_mutex); if (old->disk_attributes) sysfs_remove_group(&disk_to_dev(old->disk)->kobj, old->disk_attributes); /* Stop new requests to arrive */ del_gendisk(old->disk); /* Kill current requests */ spin_lock_irqsave(&old->queue_lock, flags); old->rq->queuedata = NULL; spin_unlock_irqrestore(&old->queue_lock, flags); /* freeze+quiesce queue to ensure all requests are flushed */ memflags = blk_mq_freeze_queue(old->rq); blk_mq_quiesce_queue(old->rq); blk_mq_unquiesce_queue(old->rq); blk_mq_unfreeze_queue(old->rq, memflags); /* If the device is currently open, tell trans driver to close it, then put mtd device, and don't touch it again */ mutex_lock(&old->lock); if (old->open) { if (old->tr->release) old->tr->release(old); __put_mtd_device(old->mtd); } old->mtd = NULL; mutex_unlock(&old->lock); blktrans_dev_put(old); return 0; } static void blktrans_notify_remove(struct mtd_info *mtd) { struct mtd_blktrans_ops *tr; struct mtd_blktrans_dev *dev, *next; list_for_each_entry(tr, &blktrans_majors, list) list_for_each_entry_safe(dev, next, &tr->devs, list) if (dev->mtd == mtd) tr->remove_dev(dev); } static void blktrans_notify_add(struct mtd_info *mtd) { struct mtd_blktrans_ops *tr; if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME) return; list_for_each_entry(tr, &blktrans_majors, list) tr->add_mtd(tr, mtd); } static struct mtd_notifier blktrans_notifier = { .add = blktrans_notify_add, .remove = blktrans_notify_remove, }; int register_mtd_blktrans(struct mtd_blktrans_ops *tr) { struct mtd_info *mtd; int ret; /* Register the notifier if/when the first device type is registered, to prevent the link/init ordering from fucking us over. */ if (!blktrans_notifier.list.next) register_mtd_user(&blktrans_notifier); ret = register_blkdev(tr->major, tr->name); if (ret < 0) { printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", tr->name, tr->major, ret); return ret; } if (ret) tr->major = ret; tr->blkshift = ffs(tr->blksize) - 1; INIT_LIST_HEAD(&tr->devs); mutex_lock(&mtd_table_mutex); list_add(&tr->list, &blktrans_majors); mtd_for_each_device(mtd) if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)