Commit e90dae1f authored by Milan Broz's avatar Milan Broz Committed by Linus Torvalds

[PATCH] dm: support ioctls on mapped devices: fix with fake file

The new ioctl code passes the wrong file pointer to the underlying device.
No file pointer is available so make a temporary fake one.

ioctl_by_bdev() does set_fs(KERNEL_DS) so it's for ioctls originating
within the kernel and unsuitable here.  We are processing ioctls that
originated in userspace and mapping them to different devices.  Fixing the
existing callers that pass a NULL file struct and consolidating the
fake_file users are separate matters to solve in later patches.
Signed-off-by: default avatarMilan Broz <mbroz@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7006f6ec
......@@ -104,8 +104,14 @@ static int linear_ioctl(struct dm_target *ti, struct inode *inode,
{
struct linear_c *lc = (struct linear_c *) ti->private;
struct block_device *bdev = lc->dev->bdev;
struct file fake_file = {};
struct dentry fake_dentry = {};
return blkdev_driver_ioctl(bdev->bd_inode, filp, bdev->bd_disk, cmd, arg);
fake_file.f_mode = lc->dev->mode;
fake_file.f_dentry = &fake_dentry;
fake_dentry.d_inode = bdev->bd_inode;
return blkdev_driver_ioctl(bdev->bd_inode, &fake_file, bdev->bd_disk, cmd, arg);
}
static struct target_type linear_target = {
......
......@@ -1273,15 +1273,22 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
struct multipath *m = (struct multipath *) ti->private;
struct block_device *bdev = NULL;
unsigned long flags;
struct file fake_file = {};
struct dentry fake_dentry = {};
int r = 0;
fake_file.f_dentry = &fake_dentry;
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pgpath)
__choose_pgpath(m);
if (m->current_pgpath)
if (m->current_pgpath) {
bdev = m->current_pgpath->path.dev->bdev;
fake_dentry.d_inode = bdev->bd_inode;
fake_file.f_mode = m->current_pgpath->path.dev->mode;
}
if (m->queue_io)
r = -EAGAIN;
......@@ -1290,8 +1297,8 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
spin_unlock_irqrestore(&m->lock, flags);
return r ? : blkdev_driver_ioctl(bdev->bd_inode, filp, bdev->bd_disk,
cmd, arg);
return r ? : blkdev_driver_ioctl(bdev->bd_inode, &fake_file,
bdev->bd_disk, cmd, arg);
}
/*-----------------------------------------------------------------
......
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