On Mon, 14 Jan 2002, Linus Torvalds wrote:
> The good news is that the bit-for-bit representation of old kdev_t and
> "dev_t" are obviously 100% the same, so we should just make the damn thing
> be dev_t, and user land will never notice anything.
>
> So we can just change all structures that are exported to user land to use
> "dev_t", and add the required conversion magic. Possibly by duplicating
> the structure, and having "used_lvm_struct_x" and functions to read and
> write them from/to user space.
... that, BTW, would kill the crap like
typedef struct ...
...
#ifdef __KERNEL__
struct kiobuf *lv_iobuf;
sector_t blocks[LVM_MAX_SECTORS];
struct kiobuf *lv_COW_table_iobuf;
struct rw_semaphore lv_lock;
struct list_head *lv_snapshot_hash_table;
uint32_t lv_snapshot_hash_table_size;
uint32_t lv_snapshot_hash_mask;
wait_queue_head_t lv_snapshot_wait;
int lv_snapshot_use_rate;
struct vg_v3 *vg;
uint lv_allocated_snapshot_le;
#else
char dummy[200];
#endif
} lv_t;
Yup, structure "shared" by kernel and userland. Look through the
include/linux/lvm.h - it's choke-full of that. And quite a few
of them contain fields like
struct proc_dir_entry *foo
struct block_device *bar
struct list_head baz
outside of these #ifdef __KERNEL__...
> > Public statement along the lines "any API that passes kdev_t values
> > across the kernel boundary is unacceptable" would be a nice thing...
>
> Consider that done. ANYTHING that exports kdev_t to user space is
> incredibly broken, and will not work in a few months when the actual bit
> representation (and size) will change.
>
> Do we have any lvm people willing to fix this? (linux-lvm cc'd, but I know
> they've been very silent on the 2.5.x changes so far)
Umm... Is the version in main tree actually maintained?
-
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/
This archive was generated by hypermail 2b29 : Tue Jan 15 2002 - 21:00:46 EST