diff options
Diffstat (limited to 'drivers/mtd/mtd_blkdevs.c')
| -rw-r--r-- | drivers/mtd/mtd_blkdevs.c | 502 |
1 files changed, 325 insertions, 177 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 839eed8430a..43e30992a36 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -1,9 +1,21 @@ /* - * $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $ + * Interface to Linux block layer for MTD 'translation layers'. * - * (C) 2003 David Woodhouse <dwmw2@infradead.org> + * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org> * - * Interface to Linux 2.5 block layer for MTD 'translation layers'. + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ @@ -16,23 +28,50 @@ #include <linux/mtd/mtd.h> #include <linux/blkdev.h> #include <linux/blkpg.h> -#include <linux/freezer.h> #include <linux/spinlock.h> #include <linux/hdreg.h> -#include <linux/init.h> #include <linux/mutex.h> -#include <linux/kthread.h> #include <asm/uaccess.h> #include "mtdcore.h" static LIST_HEAD(blktrans_majors); +static DEFINE_MUTEX(blktrans_ref_mutex); + +static void blktrans_dev_release(struct kref *kref) +{ + struct mtd_blktrans_dev *dev = + container_of(kref, struct mtd_blktrans_dev, ref); + + dev->disk->private_data = NULL; + blk_cleanup_queue(dev->rq); + put_disk(dev->disk); + list_del(&dev->list); + kfree(dev); +} + +static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) +{ + struct mtd_blktrans_dev *dev; + + mutex_lock(&blktrans_ref_mutex); + dev = disk->private_data; + + if (!dev) + goto unlock; + kref_get(&dev->ref); +unlock: + mutex_unlock(&blktrans_ref_mutex); + return dev; +} + +static void blktrans_dev_put(struct mtd_blktrans_dev *dev) +{ + mutex_lock(&blktrans_ref_mutex); + kref_put(&dev->ref, blktrans_dev_release); + mutex_unlock(&blktrans_ref_mutex); +} -struct mtd_blkcore_priv { - struct task_struct *thread; - struct request_queue *rq; - spinlock_t queue_lock; -}; static int do_blktrans_request(struct mtd_blktrans_ops *tr, struct mtd_blktrans_dev *dev, @@ -41,167 +80,237 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, unsigned long block, nsect; char *buf; - block = req->sector << 9 >> tr->blkshift; - nsect = req->current_nr_sectors << 9 >> tr->blkshift; + block = blk_rq_pos(req) << 9 >> tr->blkshift; + nsect = blk_rq_cur_bytes(req) >> tr->blkshift; + buf = bio_data(req->bio); - buf = req->buffer; + if (req->cmd_type != REQ_TYPE_FS) + return -EIO; - if (!blk_fs_request(req)) - return 0; + if (req->cmd_flags & REQ_FLUSH) + return tr->flush(dev); - if (req->sector + req->current_nr_sectors > get_capacity(req->rq_disk)) - return 0; + if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > + get_capacity(req->rq_disk)) + return -EIO; + + if (req->cmd_flags & REQ_DISCARD) + return tr->discard(dev, block, nsect); switch(rq_data_dir(req)) { case READ: for (; nsect > 0; nsect--, block++, buf += tr->blksize) if (tr->readsect(dev, block, buf)) - return 0; - return 1; - + return -EIO; + rq_flush_dcache_pages(req); + return 0; case WRITE: if (!tr->writesect) - return 0; + return -EIO; + rq_flush_dcache_pages(req); for (; nsect > 0; nsect--, block++, buf += tr->blksize) if (tr->writesect(dev, block, buf)) - return 0; - return 1; - + return -EIO; + return 0; default: printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); - return 0; + return -EIO; } } -static int mtd_blktrans_thread(void *arg) +int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev) { - struct mtd_blktrans_ops *tr = arg; - struct request_queue *rq = tr->blkcore_priv->rq; + return dev->bg_stop; +} +EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background); - /* we might get involved when memory gets low, so use PF_MEMALLOC */ - current->flags |= PF_MEMALLOC; +static void mtd_blktrans_work(struct work_struct *work) +{ + struct mtd_blktrans_dev *dev = + container_of(work, struct mtd_blktrans_dev, work); + struct mtd_blktrans_ops *tr = dev->tr; + struct request_queue *rq = dev->rq; + struct request *req = NULL; + int background_done = 0; spin_lock_irq(rq->queue_lock); - while (!kthread_should_stop()) { - struct request *req; - struct mtd_blktrans_dev *dev; - int res = 0; - - req = elv_next_request(rq); - - if (!req) { - set_current_state(TASK_INTERRUPTIBLE); - spin_unlock_irq(rq->queue_lock); - schedule(); - spin_lock_irq(rq->queue_lock); - continue; - } - dev = req->rq_disk->private_data; - tr = dev->tr; + while (1) { + int res; + + dev->bg_stop = false; + if (!req && !(req = blk_fetch_request(rq))) { + if (tr->background && !background_done) { + spin_unlock_irq(rq->queue_lock); + mutex_lock(&dev->lock); + tr->background(dev); + mutex_unlock(&dev->lock); + spin_lock_irq(rq->queue_lock); + /* + * Do background processing just once per idle + * period. + */ + background_done = !dev->bg_stop; + continue; + } + break; + } spin_unlock_irq(rq->queue_lock); mutex_lock(&dev->lock); - res = do_blktrans_request(tr, dev, req); + res = do_blktrans_request(dev->tr, dev, req); mutex_unlock(&dev->lock); spin_lock_irq(rq->queue_lock); - end_request(req, res); + if (!__blk_end_request_cur(req, res)) + req = NULL; + + background_done = 0; } - spin_unlock_irq(rq->queue_lock); - return 0; + if (req) + __blk_end_request_all(req, -EIO); + + spin_unlock_irq(rq->queue_lock); } static void mtd_blktrans_request(struct request_queue *rq) { - struct mtd_blktrans_ops *tr = rq->queuedata; - wake_up_process(tr->blkcore_priv->thread); -} + struct mtd_blktrans_dev *dev; + struct request *req = NULL; + dev = rq->queuedata; -static int blktrans_open(struct inode *i, struct file *f) + if (!dev) + while ((req = blk_fetch_request(rq)) != NULL) + __blk_end_request_all(req, -ENODEV); + else + queue_work(dev->wq, &dev->work); +} + +static int blktrans_open(struct block_device *bdev, fmode_t mode) { - struct mtd_blktrans_dev *dev; - struct mtd_blktrans_ops *tr; - int ret = -ENODEV; + struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); + int ret = 0; + + if (!dev) + return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/ - dev = i->i_bdev->bd_disk->private_data; - tr = dev->tr; + mutex_lock(&dev->lock); - if (!try_module_get(dev->mtd->owner)) - goto out; + if (dev->open) + goto unlock; - if (!try_module_get(tr->owner)) - goto out_tr; + kref_get(&dev->ref); + __module_get(dev->tr->owner); - /* FIXME: Locking. A hot pluggable device can go away - (del_mtd_device can be called for it) without its module - being unloaded. */ - dev->mtd->usecount++; + if (!dev->mtd) + goto unlock; - ret = 0; - if (tr->open && (ret = tr->open(dev))) { - dev->mtd->usecount--; - module_put(dev->mtd->owner); - out_tr: - module_put(tr->owner); + if (dev->tr->open) { + ret = dev->tr->open(dev); + if (ret) + goto error_put; } - out: + + ret = __get_mtd_device(dev->mtd); + if (ret) + goto error_release; + dev->file_mode = mode; + +unlock: + dev->open++; + mutex_unlock(&dev->lock); + blktrans_dev_put(dev); + return ret; + +error_release: + if (dev->tr->release) + dev->tr->release(dev); +error_put: + module_put(dev->tr->owner); + kref_put(&dev->ref, blktrans_dev_release); + mutex_unlock(&dev->lock); + blktrans_dev_put(dev); return ret; } -static int blktrans_release(struct inode *i, struct file *f) +static void blktrans_release(struct gendisk *disk, fmode_t mode) { - struct mtd_blktrans_dev *dev; - struct mtd_blktrans_ops *tr; - int ret = 0; + struct mtd_blktrans_dev *dev = blktrans_dev_get(disk); + + if (!dev) + return; - dev = i->i_bdev->bd_disk->private_data; - tr = dev->tr; + mutex_lock(&dev->lock); - if (tr->release) - ret = tr->release(dev); + if (--dev->open) + goto unlock; - if (!ret) { - dev->mtd->usecount--; - module_put(dev->mtd->owner); - module_put(tr->owner); - } + kref_put(&dev->ref, blktrans_dev_release); + module_put(dev->tr->owner); - return ret; + 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 block_device *bdev, struct hd_geometry *geo) { - struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; + struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); + int ret = -ENXIO; + + if (!dev) + return ret; + + mutex_lock(&dev->lock); - if (dev->tr->getgeo) - return dev->tr->getgeo(dev, geo); - return -ENOTTY; + if (!dev->mtd) + goto unlock; + + ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0; +unlock: + mutex_unlock(&dev->lock); + blktrans_dev_put(dev); + return ret; } -static int blktrans_ioctl(struct inode *inode, struct file *file, +static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { - struct mtd_blktrans_dev *dev = inode->i_bdev->bd_disk->private_data; - struct mtd_blktrans_ops *tr = dev->tr; + struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk); + int ret = -ENXIO; + + if (!dev) + return ret; + + mutex_lock(&dev->lock); + + if (!dev->mtd) + goto unlock; switch (cmd) { case BLKFLSBUF: - if (tr->flush) - return tr->flush(dev); - /* The core code did the work, we had nothing to do. */ - return 0; + ret = dev->tr->flush ? dev->tr->flush(dev) : 0; + break; default: - return -ENOTTY; + ret = -ENOTTY; } +unlock: + mutex_unlock(&dev->lock); + blktrans_dev_put(dev); + return ret; } -static struct block_device_operations mtd_blktrans_ops = { +static const struct block_device_operations mtd_block_ops = { .owner = THIS_MODULE, .open = blktrans_open, .release = blktrans_release, @@ -212,17 +321,18 @@ static struct block_device_operations mtd_blktrans_ops = { int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) { struct mtd_blktrans_ops *tr = new->tr; - struct list_head *this; + struct mtd_blktrans_dev *d; int last_devnum = -1; struct gendisk *gd; + int ret; if (mutex_trylock(&mtd_table_mutex)) { mutex_unlock(&mtd_table_mutex); BUG(); } - list_for_each(this, &tr->devs) { - struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list); + mutex_lock(&blktrans_ref_mutex); + list_for_each_entry(d, &tr->devs, list) { if (new->devnum == -1) { /* Use first free number */ if (d->devnum != last_devnum+1) { @@ -233,6 +343,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) } } else if (d->devnum == new->devnum) { /* Required number taken */ + mutex_unlock(&blktrans_ref_mutex); return -EBUSY; } else if (d->devnum > new->devnum) { /* Required number was free */ @@ -241,27 +352,41 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) } last_devnum = d->devnum; } + + ret = -EBUSY; if (new->devnum == -1) new->devnum = last_devnum+1; - if ((new->devnum << tr->part_bits) > 256) { - return -EBUSY; + /* 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)) { + mutex_unlock(&blktrans_ref_mutex); + goto error1; } list_add_tail(&new->list, &tr->devs); added: + mutex_unlock(&blktrans_ref_mutex); + mutex_init(&new->lock); + kref_init(&new->ref); if (!tr->writesect) new->readonly = 1; + /* Create gendisk */ + ret = -ENOMEM; gd = alloc_disk(1 << tr->part_bits); - if (!gd) { - list_del(&new->list); - return -ENOMEM; - } + + if (!gd) + goto error2; + + new->disk = gd; + gd->private_data = new; gd->major = tr->major; gd->first_minor = (new->devnum) << tr->part_bits; - gd->fops = &mtd_blktrans_ops; + gd->fops = &mtd_block_ops; if (tr->part_bits) if (new->devnum < 26) @@ -276,66 +401,121 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) snprintf(gd->disk_name, sizeof(gd->disk_name), "%s%d", tr->name, new->devnum); - /* 2.5 has capacity in units of 512 bytes while still - having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */ set_capacity(gd, (new->size * tr->blksize) >> 9); - gd->private_data = new; - new->blkcore_priv = gd; - gd->queue = tr->blkcore_priv->rq; + /* Create the request queue */ + spin_lock_init(&new->queue_lock); + new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock); + + if (!new->rq) + goto error3; + + if (tr->flush) + blk_queue_flush(new->rq, REQ_FLUSH); + + new->rq->queuedata = new; + blk_queue_logical_block_size(new->rq, tr->blksize); + + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq); + + if (tr->discard) { + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq); + new->rq->limits.max_discard_sectors = UINT_MAX; + } + + gd->queue = new->rq; + + /* Create processing workqueue */ + new->wq = alloc_workqueue("%s%d", 0, 0, + tr->name, new->mtd->index); + if (!new->wq) + goto error4; + INIT_WORK(&new->work, mtd_blktrans_work); + + gd->driverfs_dev = &new->mtd->dev; if (new->readonly) set_disk_ro(gd, 1); add_disk(gd); + if (new->disk_attributes) { + ret = sysfs_create_group(&disk_to_dev(gd)->kobj, + new->disk_attributes); + WARN_ON(ret); + } return 0; +error4: + blk_cleanup_queue(new->rq); +error3: + put_disk(new->disk); +error2: + list_del(&new->list); +error1: + return ret; } int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) { + unsigned long flags; + if (mutex_trylock(&mtd_table_mutex)) { mutex_unlock(&mtd_table_mutex); BUG(); } - list_del(&old->list); + 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); + + /* Stop workqueue. This will perform any pending request. */ + destroy_workqueue(old->wq); + + /* Kill current requests */ + spin_lock_irqsave(&old->queue_lock, flags); + old->rq->queuedata = NULL; + blk_start_queue(old->rq); + spin_unlock_irqrestore(&old->queue_lock, flags); + + /* 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); + } - del_gendisk(old->blkcore_priv); - put_disk(old->blkcore_priv); + old->mtd = NULL; + mutex_unlock(&old->lock); + blktrans_dev_put(old); return 0; } static void blktrans_notify_remove(struct mtd_info *mtd) { - struct list_head *this, *this2, *next; - - list_for_each(this, &blktrans_majors) { - struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list); - - list_for_each_safe(this2, next, &tr->devs) { - struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list); + 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 list_head *this; + struct mtd_blktrans_ops *tr; if (mtd->type == MTD_ABSENT) return; - list_for_each(this, &blktrans_majors) { - struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list); - + list_for_each_entry(tr, &blktrans_majors, list) tr->add_mtd(tr, mtd); - } - } static struct mtd_notifier blktrans_notifier = { @@ -345,7 +525,8 @@ static struct mtd_notifier blktrans_notifier = { int register_mtd_blktrans(struct mtd_blktrans_ops *tr) { - int ret, i; + 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 @@ -353,81 +534,48 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr) if (!blktrans_notifier.list.next) register_mtd_user(&blktrans_notifier); - tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL); - if (!tr->blkcore_priv) - return -ENOMEM; mutex_lock(&mtd_table_mutex); ret = register_blkdev(tr->major, tr->name); - if (ret) { + if (ret < 0) { printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", tr->name, tr->major, ret); - kfree(tr->blkcore_priv); mutex_unlock(&mtd_table_mutex); return ret; } - spin_lock_init(&tr->blkcore_priv->queue_lock); - tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock); - if (!tr->blkcore_priv->rq) { - unregister_blkdev(tr->major, tr->name); - kfree(tr->blkcore_priv); - mutex_unlock(&mtd_table_mutex); - return -ENOMEM; - } + if (ret) + tr->major = ret; - tr->blkcore_priv->rq->queuedata = tr; - blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize); tr->blkshift = ffs(tr->blksize) - 1; - tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr, - "%sd", tr->name); - if (IS_ERR(tr->blkcore_priv->thread)) { - blk_cleanup_queue(tr->blkcore_priv->rq); - unregister_blkdev(tr->major, tr->name); - kfree(tr->blkcore_priv); - mutex_unlock(&mtd_table_mutex); - return PTR_ERR(tr->blkcore_priv->thread); - } - INIT_LIST_HEAD(&tr->devs); list_add(&tr->list, &blktrans_majors); - for (i=0; i<MAX_MTD_DEVICES; i++) { - if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT) - tr->add_mtd(tr, mtd_table[i]); - } + mtd_for_each_device(mtd) + if (mtd->type != MTD_ABSENT) + tr->add_mtd(tr, mtd); mutex_unlock(&mtd_table_mutex); - return 0; } int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) { - struct list_head *this, *next; + struct mtd_blktrans_dev *dev, *next; mutex_lock(&mtd_table_mutex); - /* Clean up the kernel thread */ - kthread_stop(tr->blkcore_priv->thread); - /* Remove it from the list of active majors */ list_del(&tr->list); - list_for_each_safe(this, next, &tr->devs) { - struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, list); + list_for_each_entry_safe(dev, next, &tr->devs, list) tr->remove_dev(dev); - } - blk_cleanup_queue(tr->blkcore_priv->rq); unregister_blkdev(tr->major, tr->name); - mutex_unlock(&mtd_table_mutex); - kfree(tr->blkcore_priv); - BUG_ON(!list_empty(&tr->devs)); return 0; } |
