From: David Wagner <david.wagner@xxxxxxxxxxxxxxxxxx> ubiblk is a read-only block layer on top of UBI. It presents UBI volumes as read-only block devices (named ubiblk_X_Y, where X is the UBI device number and Y the Volume ID). It is used by putting a block filesystem image on a UBI volume, creating the corresponding ubiblk device and then mounting it. It uses the UBI API to register to UBI notifications and to read from the volumes. It also creates a ubiblk_ctrl device node that simply receives ioctl from a userspace tool for creating/removing ubiblk devices. Some code is taken from mtd_blkdevs and gluebi. Some code for the ioctl part is also inspired from ubi's core. Advantages of ubiblk over gluebi+mtdblock_ro: * Simpler architecture * The numbering of devices is much easier with ubiblk than with gluebi+mtdblock_ro. With gluebi+mtdblock_ro, you get one additional MTD device for each UBI volume, so the number of MTD devices grows quite a lot and is a bit difficult to understand. For example, mtdblock[0-4] might be your real MTD partitions, while mtdblock[5-9] might be your UBI volumes. It also means that if a new real MTD partition is added, the number of all the MTD devices exposing UBI volumes will be incremented by one, which is a bit confusing/annoying. As well, if you add an UBI volume, the mtdblock devices that are emulated on top of volumes that come after this new one will have their ID incremented. * ubiblk devices are created on a 'on-demand' basis, which avoids wasting resources. * The performance appears to be slightly better with ubiblk than gluebi+mtdblock_ro, according to our benchmarks (see http://elinux.org/Flash_Filesystem_Benchmarks_2.6.39) TODO: * the modules keeps a table of the devices which length is the maximum number of UBI volumes. There should be a better solution (linked list or, as Christoph Hellwig suggests, a radix tree (idr)). Signed-off-by: David Wagner <david.wagner@xxxxxxxxxxxxxxxxxx> --- Hi Artem, Here is the v3 of ubiblk implementing ioctls for on-demand creation/removal of ubiblk device ; is it what you were thinking of ? I also wrote a minimal (and ugly w.r.t argument parsing) tool in mtd-utils' git ; I'll send it as a reply to this email. known issue: attempts to create the same ubiblk device twice aren't catched and, obviously, make things go wrong (see TODO). Questions: ========== I wasn't sure what magic ioctl number to use, so I settled to use the same one as a part of UBI: 'O', which was so far only used by UBI but on a higher range and leaving some room for UBI to add ioctls (for nw, it uses 'O'/0x00-0x06 and ubiblk uses 'O'/0x10-0x11). Is it ok or should ubiblk use a different number/range ? updates from v3: =============== - Removed unused parameter "struct ubi_device_info" from ubiblk_create - Synchronisation: forgot to release a mutex on the error path of ubiblk_create - New header ubiblk-user.h, contains ioctl numbers ; patch Documentation/ioctl/ioctl-numbers.txt (use the same magic as UBI but on another range, leaving expansion margin for UBI) - Add a ioctl handler and make it use the already-existing ubiblk_{create,remove} functions (inspired from ubi/cdev.c). - Register a miscdevice (inspired from ubi/build.c) that will only receive ioctls - Notifications: don't receive a notifications for already-existing volumes upon registration ; don't create a ubiblk device when a new UBI volume appears - Amend commit message and Kconfig according to these previous points TODO: ===== - Use a dynamic structure for storing the ubiblk_devs (linked list or idr ?) - After this task is done, check that using ubiblkadd can't create an already-existing ubiblk device (see warning/todo in the code) Documentation/ioctl/ioctl-number.txt | 1 + drivers/mtd/ubi/Kconfig | 15 + drivers/mtd/ubi/Makefile | 1 + drivers/mtd/ubi/ubiblk.c | 653 ++++++++++++++++++++++++++++++++++ include/mtd/ubiblk-user.h | 43 +++ 5 files changed, 713 insertions(+), 0 deletions(-) create mode 100644 drivers/mtd/ubi/ubiblk.c create mode 100644 include/mtd/ubiblk-user.h diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 3a46e36..240cf0f 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -150,6 +150,7 @@ Code Seq#(hex) Include File Comments 'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 'N' 00-1F drivers/usb/scanner.h 'O' 00-06 mtd/ubi-user.h UBI +'O' 10-11 mtd/ubiblk-user.h ubiblk 'P' all linux/soundcard.h conflict! 'P' 60-6F sound/sscape_ioctl.h conflict! 'P' 00-0F drivers/usb/class/usblp.c conflict! diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig index 4dcc752..3eedf9a 100644 --- a/drivers/mtd/ubi/Kconfig +++ b/drivers/mtd/ubi/Kconfig @@ -60,4 +60,19 @@ config MTD_UBI_DEBUG help This option enables UBI debugging. +config MTD_UBI_UBIBLK + tristate "Read-only block transition layer on top of UBI" + help + Read-only block interface on top of UBI. + + This option adds ubiblk, which creates a read-ony block device from + UBI volumes. It makes it possible to use block filesystems on top of + UBI (and thus, on top of MTDs while avoiding bad blocks). + + ubiblk devices are created by sending appropriate ioctl to the + ubiblk_ctrl device node. + + The devices are named ubiblkX_Y where X is the UBI number and Y is + the Volume ID. + endif # MTD_UBI diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile index c9302a5..354b2df 100644 --- a/drivers/mtd/ubi/Makefile +++ b/drivers/mtd/ubi/Makefile @@ -5,3 +5,4 @@ ubi-y += misc.o ubi-$(CONFIG_MTD_UBI_DEBUG) += debug.o obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o +obj-$(CONFIG_MTD_UBI_UBIBLK) += ubiblk.o diff --git a/drivers/mtd/ubi/ubiblk.c b/drivers/mtd/ubi/ubiblk.c new file mode 100644 index 0000000..20c0896 --- /dev/null +++ b/drivers/mtd/ubi/ubiblk.c @@ -0,0 +1,653 @@ +/* + * Copyright (c) Free Electrons, 2011 + * Copyright (c) International Business Machines Corp., 2006 + * Copyright © 2003-2010 David Woodhouse <dwmw2@xxxxxxxxxxxxx> + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: David Wagner + * Some code taken from gluebi.c (Artem Bityutskiy (Ð?иÑ?Ñ?Ñ?кий Ð?Ñ?Ñ?Ñ?м), + * Joern Engel) + * Some code taken from cdev.c (Artem Bityutskiy (Ð?иÑ?Ñ?Ñ?кий Ð?Ñ?Ñ?Ñ?м)) + * Some code taken from mtd_blkdevs.c (David Woodhouse) + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/mtd/ubi.h> +#include <linux/blkdev.h> +#include <linux/miscdevice.h> +#include <linux/kthread.h> +#include <linux/mutex.h> +#include <mtd/ubiblk-user.h> +#include "ubi.h" + +#define BLK_SIZE 512 + +#define UBIBLK_MAX_DEVS (UBI_MAX_DEVICES * UBI_MAX_VOLUMES) + +/* + * Structure representing a ubiblk device, proxying a UBI volume + */ +struct ubiblk_dev { + struct ubi_volume_desc *vol_desc; + struct ubi_volume_info *vol_info; + int ubi_num; + int vol_id; + + /* Block stuff */ + struct gendisk *gd; + struct request_queue *rq; + struct task_struct *thread; + + /* Protects the access to the UBI volume */ + struct mutex lock; + + /* Avoids concurrent accesses to the request queue */ + spinlock_t queue_lock; +}; + +/* + * Contains the pointers to all ubiblk_dev instances + * TODO: use a linked list + */ +static struct ubiblk_dev *ubiblk_devs[UBIBLK_MAX_DEVS]; +static struct mutex devtable_lock; + +static int ubiblk_major; +static const struct block_device_operations ubiblk_ops; + +static struct ubiblk_dev *ubiblk_find_dev(struct ubi_volume_info *vol_info) +{ + int i; + struct ubiblk_dev *dev; + + mutex_lock(&devtable_lock); + for (i = 0; i < UBIBLK_MAX_DEVS; i++) { + dev = ubiblk_devs[i]; + if (dev && dev->ubi_num == vol_info->ubi_num && + dev->vol_id == vol_info->vol_id) + break; + } + mutex_unlock(&devtable_lock); + if (i == UBIBLK_MAX_DEVS) + return NULL; + return dev; +} + +/* + * Read a LEB and fill the request buffer with the requested sector + */ +static int do_ubiblk_request(struct request *req, struct ubiblk_dev *dev) +{ + unsigned long start, len, read_bytes; + int offset; + int leb; + int ret; + + start = blk_rq_pos(req) << 9; + len = blk_rq_cur_bytes(req); + read_bytes = 0; + + /* We are always reading. No need to handle writing for now */ + + leb = start / dev->vol_info->usable_leb_size; + offset = start % dev->vol_info->usable_leb_size; + + do { + if (offset + len > dev->vol_info->usable_leb_size) + len = dev->vol_info->usable_leb_size - offset; + + if (unlikely(blk_rq_pos(req) + blk_rq_cur_sectors(req) > + get_capacity(req->rq_disk))) { + pr_err("UBIBLK: attempting to read too far\n"); + return -EIO; + } + + pr_debug("%s(%s) of sector %llu (LEB %d). offset=%d, len=%lu\n", + __func__, rq_data_dir(req) ? "Write" : "Read", + blk_rq_pos(req), leb, offset, len); + + /* Read (len) bytes of LEB (leb) from (offset) and put the + * result in the buffer given by the request. + * If the request is overlapping on several lebs, (read_bytes) + * will be > 0 and the data will be put in the buffer at + * offset (read_bytes) + */ + ret = ubi_read(dev->vol_desc, leb, req->buffer + read_bytes, + offset, len); + + if (ret) { + pr_err("ubi_read error\n"); + return ret; + } + + read_bytes += len; + + len = blk_rq_cur_bytes(req) - read_bytes; + leb++; + offset = 0; + } while (read_bytes < blk_rq_cur_bytes(req)); + + pr_debug("ubi_read done.\n"); + + return 0; +} + +static void ubi_ubiblk_request(struct request_queue *rq) +{ + struct ubiblk_dev *dev; + struct request *req = NULL; + + dev = rq->queuedata; + + if (!dev) + while ((req = blk_fetch_request(rq)) != NULL) + __blk_end_request_all(req, -ENODEV); + else + wake_up_process(dev->thread); +} + +/* + * Open a UBI volume (get the volume descriptor) + */ +static int ubiblk_open(struct block_device *bdev, fmode_t mode) +{ + struct ubiblk_dev *dev = bdev->bd_disk->private_data; + pr_debug("%s() disk_name=%s, mode=%d\n", __func__, + bdev->bd_disk->disk_name, mode); + + dev->vol_desc = ubi_open_volume(dev->ubi_num, dev->vol_id, + UBI_READONLY); + if (!dev->vol_desc) { + pr_err("open_volume failed"); + return -EINVAL; + } + + dev->vol_info = kzalloc(sizeof(struct ubi_volume_info), GFP_KERNEL); + if (!dev->vol_info) { + ubi_close_volume(dev->vol_desc); + dev->vol_desc = NULL; + return -ENOMEM; + } + ubi_get_volume_info(dev->vol_desc, dev->vol_info); + + return 0; +} + +/* + * Close a UBI volume (close the volume descriptor) + */ +static int ubiblk_release(struct gendisk *gd, fmode_t mode) +{ + struct ubiblk_dev *dev = gd->private_data; + pr_debug("%s() disk_name=%s, mode=%d\n", __func__, gd->disk_name, mode); + + kfree(dev->vol_info); + dev->vol_info = NULL; + if (dev->vol_desc) { + ubi_close_volume(dev->vol_desc); + dev->vol_desc = NULL; + } + + return 0; +} + +/* + * Loop on the block request queue and wait for new requests ; run them with + * do_ubiblk_request() + * + * Mostly copied from mtd_blkdevs.c + */ +static int ubi_ubiblk_thread(void *arg) +{ + struct ubiblk_dev *dev = arg; + struct request_queue *rq = dev->rq; + struct request *req = NULL; + + spin_lock_irq(rq->queue_lock); + + while (!kthread_should_stop()) { + int res; + + if (!req && !(req = blk_fetch_request(rq))) { + set_current_state(TASK_INTERRUPTIBLE); + + if (kthread_should_stop()) + set_current_state(TASK_RUNNING); + + spin_unlock_irq(rq->queue_lock); + schedule(); + spin_lock_irq(rq->queue_lock); + continue; + } + + spin_unlock_irq(rq->queue_lock); + + mutex_lock(&dev->lock); + res = do_ubiblk_request(req, dev); + pr_debug("return from request: %d\n", res); + mutex_unlock(&dev->lock); + + spin_lock_irq(rq->queue_lock); + + if (!__blk_end_request_cur(req, res)) + req = NULL; + } + + if (req) + __blk_end_request_all(req, -EIO); + + spin_unlock_irq(rq->queue_lock); + + return 0; +} + +/* + * An UBI volume has been created ; create a corresponding ubiblk device: + * Initialize the locks, the structure, the block layer infos and start a + * thread. + */ +static int ubiblk_create(struct ubi_volume_info *vol_info) +{ + struct ubiblk_dev *dev; + struct gendisk *gd; + int i; + int ret = 0; + + mutex_lock(&devtable_lock); +#warning "TODO: Make sure the ubiblk device doesn't already exist (to be done after introducing the use of a dynamic structure for storing the ubiblk_devs)" + for (i = 0; i < UBIBLK_MAX_DEVS; i++) + if (!ubiblk_devs[i]) + break; + + if (i == UBIBLK_MAX_DEVS) { + /* Shouldn't happen: UBI can't make more volumes than that */ + pr_err("no slot left for a new ubiblk device.\n"); + mutex_unlock(&devtable_lock); + return -ENOMEM; + } + + dev = kzalloc(sizeof(struct ubiblk_dev), GFP_KERNEL); + if (!dev) { + pr_err("UBIBLK: ENOMEM when trying to create a new" + "ubiblk dev\n"); + mutex_unlock(&devtable_lock); + return -ENOMEM; + } + ubiblk_devs[i] = dev; + mutex_unlock(&devtable_lock); + + mutex_init(&dev->lock); + mutex_lock(&dev->lock); + + dev->ubi_num = vol_info->ubi_num; + dev->vol_id = vol_info->vol_id; + + dev->vol_desc = ubi_open_volume(dev->ubi_num, dev->vol_id, + UBI_READONLY); + if (IS_ERR(dev->vol_desc)) { + pr_err("open_volume failed\n"); + ret = PTR_ERR(dev->vol_desc); + goto out_vol; + } + + dev->vol_info = kzalloc(sizeof(struct ubi_volume_info), GFP_KERNEL); + if (!dev->vol_info) { + ret = -ENOMEM; + goto out_info; + } + ubi_get_volume_info(dev->vol_desc, dev->vol_info); + + pr_info("Got volume %s: device %d/volume %d of size %d\n", + dev->vol_info->name, dev->ubi_num, dev->vol_id, + dev->vol_info->size); + + /* Initialize the gendisk of this ubiblk device */ + gd = alloc_disk(1); + if (!gd) { + pr_err("alloc_disk failed\n"); + ret = -ENODEV; + goto out_disk; + } + + gd->fops = &ubiblk_ops; + gd->major = ubiblk_major; + gd->first_minor = dev->ubi_num * UBI_MAX_VOLUMES + dev->vol_id; + gd->private_data = dev; + sprintf(gd->disk_name, "ubiblk%d_%d", dev->ubi_num, dev->vol_id); + pr_debug("creating a gd '%s'\n", gd->disk_name); + set_capacity(gd, + (dev->vol_info->size * + dev->vol_info->usable_leb_size) >> 9); + set_disk_ro(gd, 1); + dev->gd = gd; + + spin_lock_init(&dev->queue_lock); + dev->rq = blk_init_queue(ubi_ubiblk_request, &dev->queue_lock); + if (!dev->rq) { + pr_err("init_queue failed\n"); + ret = -ENODEV; + goto out_queue; + } + dev->rq->queuedata = dev; + blk_queue_logical_block_size(dev->rq, BLK_SIZE); + dev->gd->queue = dev->rq; + + /* Stolen from mtd_blkdevs.c */ + /* Create processing thread + * + * The processing of the request has to be done in process context (it + * might sleep) but blk_run_queue can't block ; so we need to separate + * the event of a request being added to the queue (which triggers the + * callback ubi_ubiblk_request - that is set with blk_init_queue()) + * and the processing of that request. + * + * Thus, the sole purpose of ubi_ubiblk_reuqest is to wake the kthread + * up so that it will process the request queue + */ + dev->thread = kthread_run(ubi_ubiblk_thread, dev, "%s%d_%d", + "kubiblk", dev->ubi_num, dev->vol_id); + if (IS_ERR(dev->thread)) { + ret = PTR_ERR(dev->thread); + goto out_thread; + } + + add_disk(dev->gd); + kfree(dev->vol_info); + dev->vol_info = NULL; + ubi_close_volume(dev->vol_desc); + dev->vol_desc = NULL; + mutex_unlock(&dev->lock); + + return 0; + +out_thread: + blk_cleanup_queue(dev->rq); +out_queue: + put_disk(dev->gd); +out_disk: + kfree(dev->vol_info); + dev->vol_info = NULL; +out_info: + ubi_close_volume(dev->vol_desc); + dev->vol_desc = NULL; +out_vol: + mutex_unlock(&dev->lock); + + return ret; +} + +/* + * A UBI has been removed ; destroy the corresponding ubiblk device + */ +static int ubiblk_remove(struct ubi_volume_info *vol_info) +{ + int i; + struct ubiblk_dev *dev; + + mutex_lock(&devtable_lock); + for (i = 0; i < UBIBLK_MAX_DEVS; i++) { + dev = ubiblk_devs[i]; + if (dev && dev->ubi_num == vol_info->ubi_num && + dev->vol_id == vol_info->vol_id) + break; + } + if (i == UBIBLK_MAX_DEVS) { + mutex_unlock(&devtable_lock); + pr_warn("Trying to remove %s, but it isn't handled by ubiblk\n", + vol_info->name); + return -ENODEV; + } + + pr_info("ubiblk: Removing %s\n", vol_info->name); + + if (dev->vol_desc) { + ubi_close_volume(dev->vol_desc); + dev->vol_desc = NULL; + } + + del_gendisk(dev->gd); + blk_cleanup_queue(dev->rq); + kthread_stop(dev->thread); + put_disk(dev->gd); + + kfree(dev->vol_info); + + kfree(ubiblk_devs[i]); + ubiblk_devs[i] = NULL; + + mutex_unlock(&devtable_lock); + return 0; +} + +static int ubiblk_resized(struct ubi_volume_info *vol_info) +{ + struct ubiblk_dev *dev; + + dev = ubiblk_find_dev(vol_info); + if (!dev) { + pr_warn("Trying to resize %s, which is unknown from ubiblk\n", + vol_info->name); + return -ENODEV; + } + + mutex_lock(&dev->lock); + set_capacity(dev->gd, + (vol_info->size * vol_info->usable_leb_size) >> 9); + mutex_unlock(&dev->lock); + pr_debug("Resized ubiblk%d_%d to %d LEBs\n", vol_info->ubi_num, + vol_info->vol_id, vol_info->size); + return 0; +} + +/* + * Dispatches the UBI notifications + * copied from gluebi.c + */ +static int ubiblk_notify(struct notifier_block *nb, + unsigned long notification_type, void *ns_ptr) +{ + struct ubi_notification *nt = ns_ptr; + + switch (notification_type) { + case UBI_VOLUME_ADDED: + break; + case UBI_VOLUME_REMOVED: + ubiblk_remove(&nt->vi); + break; + case UBI_VOLUME_RESIZED: + ubiblk_resized(&nt->vi); + break; + case UBI_VOLUME_UPDATED: + break; + case UBI_VOLUME_RENAMED: + break; + default: + break; + } + return NOTIFY_OK; +} + +static const struct block_device_operations ubiblk_ops = { + .owner = THIS_MODULE, + .open = ubiblk_open, + .release = ubiblk_release, +}; + +static struct notifier_block ubiblk_notifier = { + .notifier_call = ubiblk_notify, +}; + + +/* + * ioctl handling for managing/unmanaging a UBI volume + */ + +static long ubiblk_ctrl_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int err = 0; + void __user *argp = (void __user *)arg; + + struct ubi_volume_desc *vol_desc; + struct ubi_volume_info vol_info; + struct ubiblk_ctrl_req req; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + err = copy_from_user(&req, argp, sizeof(struct ubiblk_ctrl_req)); + if (err) + return -EFAULT; + + if (req.ubi_num < 0 || req.vol_id < 0) + return -EINVAL; + + vol_desc = ubi_open_volume(req.ubi_num, req.vol_id, UBI_READONLY); + if (IS_ERR(vol_desc)) { + pr_err("Opening volume %d on device %d failed\n", + req.vol_id, req.ubi_num); + return PTR_ERR(vol_desc); + } + + ubi_get_volume_info(vol_desc, &vol_info); + + switch (cmd) { + case UBIBLK_IOCADD: + pr_info("Creating a ubiblk device proxing ubi%d:%d\n", + req.ubi_num, req.vol_id); + ubiblk_create(&vol_info); + break; + case UBIBLK_IOCDEL: + pr_info("Removing ubiblk from ubi%d:%d\n", + req.ubi_num, req.vol_id); + ubiblk_remove(&vol_info); + break; + + default: + err = -ENOTTY; + break; + } + + return err; +} + +#ifdef CONFIG_COMPAT +static long ubiblk_ctrl_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + unsigned long translated_arg = (unsigned long)compat_ptr(arg); + + return ubiblk_ctrl_ioctl(file, cmd, translated_arg); +} +#endif + +/* ubiblk control device (receives ioctls) */ +static const struct file_operations ubiblk_ctrl_ops = { + .owner = THIS_MODULE, + .unlocked_ioctl = ubiblk_ctrl_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = ubiblk_ctrl_compat_ioctl, +#endif + .llseek = no_llseek, +}; +static struct miscdevice ubiblk_ctrl_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "ubiblk_ctrl", + .fops = &ubiblk_ctrl_ops, +}; + +/* + * Initialize the module + * (Get a major number and register to UBI notifications) + */ +static int __init ubi_ubiblk_init(void) +{ + int ret = 0; + + pr_info("UBIBLK starting\n"); + + ret = register_blkdev(0, "ubiblk"); + if (ret <= 0) { + pr_err("UBIBLK: could not register_blkdev\n"); + return -ENODEV; + } + ubiblk_major = ret; + pr_info("UBIBLK: device's major: %d\n", ubiblk_major); + + mutex_init(&devtable_lock); + + ret = misc_register(&ubiblk_ctrl_dev); + if (ret) { + pr_err("Cannot register ubiblk_ctrl\n"); + goto out_unreg_blk; + } + + ret = ubi_register_volume_notifier(&ubiblk_notifier, 1); + if (ret < 0) + goto out_unreg_ctrl; + + return ret; + +out_unreg_ctrl: + misc_deregister(&ubiblk_ctrl_dev); +out_unreg_blk: + unregister_blkdev(ubiblk_major, "ubiblk"); + + return ret; +} + +/* + * End of life + * unregister the block device major, unregister from UBI notifications, + * stop the threads and free the memory. + */ +static void __exit ubi_ubiblk_exit(void) +{ + int i; + + pr_info("UBIBLK: going to exit\n"); + + ubi_unregister_volume_notifier(&ubiblk_notifier); + misc_deregister(&ubiblk_ctrl_dev); + + for (i = 0; i < UBIBLK_MAX_DEVS; i++) { + struct ubiblk_dev *dev = ubiblk_devs[i]; + if (!dev) + continue; + + if (dev->vol_desc) + ubi_close_volume(dev->vol_desc); + + del_gendisk(dev->gd); + blk_cleanup_queue(dev->rq); + kthread_stop(dev->thread); + put_disk(dev->gd); + + kfree(dev->vol_info); + kfree(ubiblk_devs[i]); + } + + unregister_blkdev(ubiblk_major, "ubiblk"); + pr_info("UBIBLK: The End\n"); +} + +module_init(ubi_ubiblk_init); +module_exit(ubi_ubiblk_exit); +MODULE_DESCRIPTION("Read-only block transition layer on top of UBI"); +MODULE_AUTHOR("David Wagner"); +MODULE_LICENSE("GPL"); diff --git a/include/mtd/ubiblk-user.h b/include/mtd/ubiblk-user.h new file mode 100644 index 0000000..fa0d007 --- /dev/null +++ b/include/mtd/ubiblk-user.h @@ -0,0 +1,43 @@ +/* + * Copyright © Free Electrons, 2011 + * Copyright © International Business Machines Corp., 2006 + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: David Wagner + * Some code taken from ubi-user.h + */ + +#ifndef __UBIBLK_USER_H__ +#define __UBIBLK_USER_H__ + +#include <linux/types.h> + +/* Structure to be passed to UBIBLK_IOCADD or IOCDEL ioctl */ +struct ubiblk_ctrl_req { + __s32 ubi_num; + __s32 vol_id; +}; + +/* ioctl commands of the UBI control character device */ + +#define UBIBLK_CTRL_IOC_MAGIC 'O' + +/* Create a ubiblk device from a UBI volume */ +#define UBIBLK_IOCADD _IOW(UBIBLK_CTRL_IOC_MAGIC, 0x10, struct ubiblk_ctrl_req) +/* Delete a ubiblk device */ +#define UBIBLK_IOCDEL _IOW(UBIBLK_CTRL_IOC_MAGIC, 0x11, struct ubiblk_ctrl_req) + +#endif -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
