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[PATCH] block: add unlocked_ioctl support for block devices

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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 <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Arnd Bergmann 2005-06-23 00:10:15 -07:00 committed by Linus Torvalds
parent 0d77e5a2c2
commit bb93e3a52f
3 changed files with 57 additions and 23 deletions
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74
drivers/block/ioctl.c
View File

@ -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.

5
fs/block_dev.c
View File

@ -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

1
include/linux/fs.h
View File

@ -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 *);