--- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -29,6 +29,8 @@ struct block2mtd_dev { struct block_device *blkdev; struct mtd_info mtd; struct mutex write_mutex; + rwlock_t bdev_mutex; + char devname[0]; }; @@ -79,6 +81,12 @@ static int block2mtd_erase(struct mtd_in size_t len = instr->len; int err; + read_lock(&dev->bdev_mutex); + if (!dev->blkdev) { + err = -EINVAL; + goto done; + } + instr->state = MTD_ERASING; mutex_lock(&dev->write_mutex); err = _block2mtd_erase(dev, from, len); @@ -90,6 +98,10 @@ static int block2mtd_erase(struct mtd_in instr->state = MTD_ERASE_DONE; mtd_erase_callback(instr); + +done: + read_unlock(&dev->bdev_mutex); + return err; } @@ -101,7 +113,13 @@ static int block2mtd_read(struct mtd_inf struct page *page; int index = from >> PAGE_SHIFT; int offset = from & (PAGE_SIZE-1); - int cpylen; + int cpylen, err = 0; + + read_lock(&dev->bdev_mutex); + if (!dev->blkdev || (from > mtd->size)) { + err = -EINVAL; + goto done; + } while (len) { if ((offset + len) > PAGE_SIZE) @@ -111,8 +129,10 @@ static int block2mtd_read(struct mtd_inf len = len - cpylen; page = page_read(dev->blkdev->bd_inode->i_mapping, index); - if (IS_ERR(page)) + if (IS_ERR(page)) { return PTR_ERR(page); + goto done; + } memcpy(buf, page_address(page) + offset, cpylen); page_cache_release(page); @@ -123,7 +143,10 @@ static int block2mtd_read(struct mtd_inf offset = 0; index++; } - return 0; + +done: + read_unlock(&dev->bdev_mutex); + return err; } @@ -171,13 +194,22 @@ static int block2mtd_write(struct mtd_in size_t *retlen, const u_char *buf) { struct block2mtd_dev *dev = mtd->priv; - int err; + int err = 0; + + read_lock(&dev->bdev_mutex); + if (!dev->blkdev) { + err = -EINVAL; + goto done; + } mutex_lock(&dev->write_mutex); err = _block2mtd_write(dev, buf, to, len, retlen); mutex_unlock(&dev->write_mutex); if (err > 0) err = 0; + +done: + read_unlock(&dev->bdev_mutex); return err; } @@ -186,33 +218,110 @@ static int block2mtd_write(struct mtd_in static void block2mtd_sync(struct mtd_info *mtd) { struct block2mtd_dev *dev = mtd->priv; + read_lock(&dev->bdev_mutex); + if (dev->blkdev) sync_blockdev(dev->blkdev); + read_unlock(&dev->bdev_mutex); + return; } +static int _open_bdev(struct block2mtd_dev *dev) +{ + const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL; + struct block_device *bdev; + + /* Get a handle on the device */ + bdev = blkdev_get_by_path(dev->devname, mode, dev); +#ifndef MODULE + if (IS_ERR(bdev)) { + dev_t devt; + + /* We might not have rootfs mounted at this point. Try + to resolve the device name by other means. */ + + devt = name_to_dev_t(dev->devname); + if (devt) + bdev = blkdev_get_by_dev(devt, mode, dev); + } +#endif + + if (IS_ERR(bdev)) { + ERROR("error: cannot open device %s", dev->devname); + return 1; + } + dev->blkdev = bdev; + + if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { + ERROR("attempting to use an MTD device as a block device"); + return 1; + } + + return 0; +} + +static void _close_bdev(struct block2mtd_dev *dev) +{ + struct block_device *bdev; + + if (!dev->blkdev) + return; + + bdev = dev->blkdev; + invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1); + blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); + dev->blkdev = NULL; +} + static void block2mtd_free_device(struct block2mtd_dev *dev) { if (!dev) return; kfree(dev->mtd.name); - - if (dev->blkdev) { - invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, - 0, -1); - blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); - } - + _close_bdev(dev); kfree(dev); } -/* FIXME: ensure that mtd->size % erase_size == 0 */ -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname) +static int block2mtd_refresh(struct mtd_info *mtd) { - const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL; + struct block2mtd_dev *dev = mtd->priv; struct block_device *bdev; + dev_t devt; + int err = 0; + + /* no other mtd function can run at this point */ + write_lock(&dev->bdev_mutex); + + /* get the device number for the whole disk */ + devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0); + + /* close the old block device */ + _close_bdev(dev); + + /* open the whole disk, issue a partition rescan, then */ + bdev = blkdev_get_by_dev(devt, FMODE_WRITE | FMODE_READ, mtd); + if (!bdev || !bdev->bd_disk) + err = -EINVAL; +#ifndef CONFIG_MTD_BLOCK2MTD_MODULE + else + err = rescan_partitions(bdev->bd_disk, bdev); +#endif + if (bdev) + blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); + + /* try to open the partition block device again */ + _open_bdev(dev); + write_unlock(&dev->bdev_mutex); + + return err; +} + +/* FIXME: ensure that mtd->size % erase_size == 0 */ +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname) +{ struct block2mtd_dev *dev; struct mtd_partition *part; char *name; @@ -220,36 +329,17 @@ static struct block2mtd_dev *add_device( if (!devname) return NULL; - dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL); + dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL); if (!dev) return NULL; - /* Get a handle on the device */ - bdev = blkdev_get_by_path(devname, mode, dev); -#ifndef MODULE - if (IS_ERR(bdev)) { + strcpy(dev->devname, devname); - /* We might not have rootfs mounted at this point. Try - to resolve the device name by other means. */ - - dev_t devt = name_to_dev_t(devname); - if (devt) - bdev = blkdev_get_by_dev(devt, mode, dev); - } -#endif - - if (IS_ERR(bdev)) { - ERROR("error: cannot open device %s", devname); - goto devinit_err; - } - dev->blkdev = bdev; - - if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { - ERROR("attempting to use an MTD device as a block device"); + if (_open_bdev(dev)) goto devinit_err; - } mutex_init(&dev->write_mutex); + rwlock_init(&dev->bdev_mutex); /* Setup the MTD structure */ /* make the name contain the block device in */ @@ -274,6 +364,7 @@ static struct block2mtd_dev *add_device( dev->mtd._read = block2mtd_read; dev->mtd.priv = dev; dev->mtd.owner = THIS_MODULE; + dev->mtd.refresh_device = block2mtd_refresh; part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL); part->name = name;