Messages in this thread | | | Date | Tue, 30 Oct 2007 13:01:37 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Allow auto-destruction of loop devices. |
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On Sun, 28 Oct 2007 19:08:31 -0400 David Woodhouse <dwmw2@infradead.org> wrote:
> This allows a flag to be set on loop devices so that when they are > closed for the last time, they'll self-destruct. >
Why do we want to do this?
> > diff --git a/drivers/block/loop.c b/drivers/block/loop.c > index 56e2304..7fae828 100644 > --- a/drivers/block/loop.c > +++ b/drivers/block/loop.c > @@ -973,6 +973,10 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > lo->transfer = xfer->transfer; > lo->ioctl = xfer->ioctl; > > + if ( (lo->lo_flags & LO_FLAGS_AUTOCLEAR) != > + (info->lo_flags & LO_FLAGS_AUTOCLEAR)) > + lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; > + > lo->lo_encrypt_key_size = info->lo_encrypt_key_size; > lo->lo_init[0] = info->lo_init[0]; > lo->lo_init[1] = info->lo_init[1]; > @@ -1331,6 +1335,10 @@ static int lo_release(struct inode *inode, struct file *file) > > mutex_lock(&lo->lo_ctl_mutex); > --lo->lo_refcnt; > + > + if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) && !lo->lo_refcnt) > + loop_clr_fd(lo, inode->i_bdev); > + > mutex_unlock(&lo->lo_ctl_mutex); > > return 0; > diff --git a/include/linux/loop.h b/include/linux/loop.h > index 26a0a10..46169a7 100644 > --- a/include/linux/loop.h > +++ b/include/linux/loop.h > @@ -76,6 +76,7 @@ struct loop_device { > enum { > LO_FLAGS_READ_ONLY = 1, > LO_FLAGS_USE_AOPS = 2, > + LO_FLAGS_AUTOCLEAR = 4, > }; > > #include <asm/posix_types.h> /* for __kernel_old_dev_t */ > > -- > dwmw2 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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