From bb93e3a52f8db7210258a1a2134cced0b78a46e1 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 23 Jun 2005 00:10:15 -0700 Subject: [PATCH] [PATCH] block: add unlocked_ioctl support for block devices This patch allows block device drivers to convert their ioctl functions to unlocked_ioctl() like character devices and other subsystems. All functions that were called with the BKL held before are still used that way, but I would not be surprised if it could be removed from the ioctl functions in drivers/block/ioctl.c themselves. As a side note, I found that compat_blkdev_ioctl() acquires the BKL as well, which looks like a bug. I have checked that every user of disk->fops->compat_ioctl() in the current git tree gets the BKL itself, so it could easily be removed from compat_blkdev_ioctl(). Signed-off-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/ioctl.c | 74 +++++++++++++++++++++++++++++++------------ fs/block_dev.c | 5 ++- include/linux/fs.h | 1 + 3 files changed, 57 insertions(+), 23 deletions(-) diff --git a/drivers/block/ioctl.c b/drivers/block/ioctl.c index 6d7bcc9da9e7..6e278474f9a8 100644 --- a/drivers/block/ioctl.c +++ b/drivers/block/ioctl.c @@ -133,11 +133,9 @@ static int put_u64(unsigned long arg, u64 val) return put_user(val, (u64 __user *)arg); } -int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd, - unsigned long arg) +static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev, + unsigned cmd, unsigned long arg) { - struct block_device *bdev = inode->i_bdev; - struct gendisk *disk = bdev->bd_disk; struct backing_dev_info *bdi; int ret, n; @@ -190,36 +188,72 @@ int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd, return put_ulong(arg, bdev->bd_inode->i_size >> 9); case BLKGETSIZE64: return put_u64(arg, bdev->bd_inode->i_size); + } + return -ENOIOCTLCMD; +} + +static int blkdev_driver_ioctl(struct inode *inode, struct file *file, + struct gendisk *disk, unsigned cmd, unsigned long arg) +{ + int ret; + if (disk->fops->unlocked_ioctl) + return disk->fops->unlocked_ioctl(file, cmd, arg); + + if (disk->fops->ioctl) { + lock_kernel(); + ret = disk->fops->ioctl(inode, file, cmd, arg); + unlock_kernel(); + return ret; + } + + return -ENOTTY; +} + +int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd, + unsigned long arg) +{ + struct block_device *bdev = inode->i_bdev; + struct gendisk *disk = bdev->bd_disk; + int ret, n; + + switch(cmd) { case BLKFLSBUF: if (!capable(CAP_SYS_ADMIN)) return -EACCES; - if (disk->fops->ioctl) { - ret = disk->fops->ioctl(inode, file, cmd, arg); - /* -EINVAL to handle old uncorrected drivers */ - if (ret != -EINVAL && ret != -ENOTTY) - return ret; - } + + ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg); + /* -EINVAL to handle old uncorrected drivers */ + if (ret != -EINVAL && ret != -ENOTTY) + return ret; + + lock_kernel(); fsync_bdev(bdev); invalidate_bdev(bdev, 0); + unlock_kernel(); return 0; + case BLKROSET: - if (disk->fops->ioctl) { - ret = disk->fops->ioctl(inode, file, cmd, arg); - /* -EINVAL to handle old uncorrected drivers */ - if (ret != -EINVAL && ret != -ENOTTY) - return ret; - } + ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg); + /* -EINVAL to handle old uncorrected drivers */ + if (ret != -EINVAL && ret != -ENOTTY) + return ret; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (get_user(n, (int __user *)(arg))) return -EFAULT; + lock_kernel(); set_device_ro(bdev, n); + unlock_kernel(); return 0; - default: - if (disk->fops->ioctl) - return disk->fops->ioctl(inode, file, cmd, arg); } - return -ENOTTY; + + lock_kernel(); + ret = blkdev_locked_ioctl(file, bdev, cmd, arg); + unlock_kernel(); + if (ret != -ENOIOCTLCMD) + return ret; + + return blkdev_driver_ioctl(inode, file, disk, cmd, arg); } /* Most of the generic ioctls are handled in the normal fallback path. diff --git a/fs/block_dev.c b/fs/block_dev.c index c0cbd1bc1a02..e0df94c37b7e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -777,8 +777,7 @@ static ssize_t blkdev_file_aio_write(struct kiocb *iocb, const char __user *buf, return generic_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos); } -static int block_ioctl(struct inode *inode, struct file *file, unsigned cmd, - unsigned long arg) +static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) { return blkdev_ioctl(file->f_mapping->host, file, cmd, arg); } @@ -803,7 +802,7 @@ struct file_operations def_blk_fops = { .aio_write = blkdev_file_aio_write, .mmap = generic_file_mmap, .fsync = block_fsync, - .ioctl = block_ioctl, + .unlocked_ioctl = block_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = compat_blkdev_ioctl, #endif diff --git a/include/linux/fs.h b/include/linux/fs.h index 3622e952e98c..9b1278e21279 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -884,6 +884,7 @@ struct block_device_operations { int (*open) (struct inode *, struct file *); int (*release) (struct inode *, struct file *); int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long); + long (*unlocked_ioctl) (struct file *, unsigned, unsigned long); long (*compat_ioctl) (struct file *, unsigned, unsigned long); int (*media_changed) (struct gendisk *); int (*revalidate_disk) (struct gendisk *); -- 2.30.2