From a863862257b7dd08d855bafcb0aedd9ad848ed91 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 22 Feb 2010 20:39:29 +0200 Subject: [PATCH] mtd: blktrans: remove mtd_blkcore_priv, switch to per device queue and thread This is the biggest change. To make hotplug possible, and this layer clean, the mtd_blktrans_dev now contains everything for a single mtd block translation device. Also removed some very old leftovers. Signed-off-by: Maxim Levitsky Signed-off-by: David Woodhouse --- drivers/mtd/mtd_blkdevs.c | 124 ++++++++++++++++------------------- include/linux/mtd/blktrans.h | 10 +-- 2 files changed, 63 insertions(+), 71 deletions(-) diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 2f8c202dbd86..6a572625bfc0 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include @@ -26,11 +25,6 @@ static LIST_HEAD(blktrans_majors); -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, @@ -61,7 +55,6 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, return -EIO; rq_flush_dcache_pages(req); return 0; - case WRITE: if (!tr->writesect) return -EIO; @@ -71,7 +64,6 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, if (tr->writesect(dev, block, buf)) return -EIO; return 0; - default: printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); return -EIO; @@ -80,14 +72,13 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, static int mtd_blktrans_thread(void *arg) { - struct mtd_blktrans_ops *tr = arg; - struct request_queue *rq = tr->blkcore_priv->rq; + struct mtd_blktrans_dev *dev = arg; + struct request_queue *rq = dev->rq; struct request *req = NULL; spin_lock_irq(rq->queue_lock); while (!kthread_should_stop()) { - struct mtd_blktrans_dev *dev; int res; if (!req && !(req = blk_fetch_request(rq))) { @@ -98,13 +89,10 @@ static int mtd_blktrans_thread(void *arg) continue; } - dev = req->rq_disk->private_data; - tr = dev->tr; - 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); @@ -123,8 +111,8 @@ static int mtd_blktrans_thread(void *arg) 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 = rq->queuedata; + wake_up_process(dev->thread); } @@ -214,6 +202,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 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); @@ -239,6 +228,8 @@ 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; @@ -247,7 +238,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) * with this number. */ if (new->devnum > (MINORMASK >> tr->part_bits) || (tr->part_bits && new->devnum >= 27 * 26)) - return -EBUSY; + goto error1; list_add_tail(&new->list, &tr->devs); added: @@ -255,11 +246,16 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 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; @@ -277,21 +273,49 @@ 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; + + new->rq->queuedata = new; + blk_queue_logical_block_size(new->rq, tr->blksize); + + if (tr->discard) + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, + new->rq); + + gd->queue = new->rq; + + /* Create processing thread */ + /* TODO: workqueue ? */ + new->thread = kthread_run(mtd_blktrans_thread, new, + "%s%d", tr->name, new->mtd->index); + if (IS_ERR(new->thread)) { + ret = PTR_ERR(new->thread); + goto error4; + } gd->driverfs_dev = &new->mtd->dev; if (new->readonly) set_disk_ro(gd, 1); add_disk(gd); - return 0; +error4: + blk_cleanup_queue(new->rq); +error3: + put_disk(new->disk); +error2: + list_del(&new->list); +error1: + kfree(new); + return ret; } int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) @@ -303,9 +327,13 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) list_del(&old->list); - del_gendisk(old->blkcore_priv); - put_disk(old->blkcore_priv); + /* stop new requests to arrive */ + del_gendisk(old->disk); + /* Stop the thread */ + kthread_stop(old->thread); + + blk_cleanup_queue(old->rq); return 0; } @@ -347,9 +375,6 @@ 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); @@ -357,39 +382,12 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr) if (ret) { 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; - } - - tr->blkcore_priv->rq->queuedata = tr; - blk_queue_logical_block_size(tr->blkcore_priv->rq, tr->blksize); - if (tr->discard) - queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, - tr->blkcore_priv->rq); 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)) { - ret = PTR_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 ret; - } - INIT_LIST_HEAD(&tr->devs); list_add(&tr->list, &blktrans_majors); @@ -408,8 +406,6 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) 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); @@ -417,13 +413,9 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) 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; } diff --git a/include/linux/mtd/blktrans.h b/include/linux/mtd/blktrans.h index 8b4aa0523db7..a4b392868b54 100644 --- a/include/linux/mtd/blktrans.h +++ b/include/linux/mtd/blktrans.h @@ -24,11 +24,13 @@ struct mtd_blktrans_dev { int devnum; unsigned long size; int readonly; - void *blkcore_priv; /* gendisk in 2.5, devfs_handle in 2.4 */ + struct gendisk *disk; + struct task_struct *thread; + struct request_queue *rq; + spinlock_t queue_lock; + void *priv; }; -struct blkcore_priv; /* Differs for 2.4 and 2.5 kernels; private */ - struct mtd_blktrans_ops { char *name; int major; @@ -60,8 +62,6 @@ struct mtd_blktrans_ops { struct list_head devs; struct list_head list; struct module *owner; - - struct mtd_blkcore_priv *blkcore_priv; }; extern int register_mtd_blktrans(struct mtd_blktrans_ops *tr); -- 2.20.1