On 12.11.18 г. 6:58 ч., Anand Jain wrote:
>
> The dev_replace_state defines are miss matched between the
> BTRFS_IOCTL_DEV_REPLACE_STATE_* and BTRFS_DEV_REPLACE_ITEM_STATE_* [1].
>
> [1]
> -----------------------------
> btrfs.h:#define BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED 2
> btrfs.h:#define BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 3
> btrfs.h:#define BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED 4
>
> btrfs_tree.h:#define BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED 2
> btrfs_tree.h:#define BTRFS_DEV_REPLACE_ITEM_STATE_FINISHED 3
> btrfs_tree.h:#define BTRFS_DEV_REPLACE_ITEM_STATE_CANCELED 4
> -----------------------------
>
> The BTRFS_DEV_REPLACE_ITEM_STATE_* series is unused in both btrfs.ko and
> btrfs-progs, the on-disk also follows BTRFS_IOCTL_DEV_REPLACE_STATE_*
> (we set dev_replace->replace_state using the
> BTRFS_IOCTL_DEV_REPLACE_STATE_* defines and write to the on-disk).
>
> 359 btrfs_set_dev_replace_replace_state(eb, ptr,
> 360 dev_replace->replace_state);
>
> IMO it should be ok to delete the BTRFS_DEV_REPLACE_ITEM_STATE_*
> altogether? But how about the userland progs other than btrfs-progs?
> If not at least fix the miss match as in [2], any comments?
Unfortunately you are right. This seems to stem from sloppy job back in
the days of initial dev-replace support. BTRFS_DEV_REPLACE_ITEM_STATE_*
were added in e922e087a35c ("Btrfs: enhance btrfs structures for device
replace support"), yet they were never used. And the
IOCTL_DEV_REPLACE_STATE* were added in e93c89c1aaaa ("Btrfs: add new
sources for device replace code").
It looks like the ITEM_STATE* definitions were stillborn so to speak and
personally I'm in favor of removing them. They shouldn't have been
merged in the first place and indeed the patch doesn't even have a
Reviewed-by tag. So it originated from the, I'd say, spartan days of
btrfs development...
David, any code which is using BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED
is inherently broken, so how about we remove those definitions, then
when it's compilation is broken in the future the author will actually
have a chance to fix it, though it's highly unlikely anyone is relying
on those definitions.
>
> [2]
> --------------------------------------
> diff --git a/include/uapi/linux/btrfs_tree.h
> b/include/uapi/linux/btrfs_tree.h
> index aff1356c2bb8..9ffa7534cadf 100644
> --- a/include/uapi/linux/btrfs_tree.h
> +++ b/include/uapi/linux/btrfs_tree.h
> @@ -805,9 +805,9 @@ struct btrfs_dev_stats_item {
> #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1
> #define BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED 0
> #define BTRFS_DEV_REPLACE_ITEM_STATE_STARTED 1
> -#define BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED 2
> -#define BTRFS_DEV_REPLACE_ITEM_STATE_FINISHED 3
> -#define BTRFS_DEV_REPLACE_ITEM_STATE_CANCELED 4
> +#define BTRFS_DEV_REPLACE_ITEM_STATE_FINISHED 2
> +#define BTRFS_DEV_REPLACE_ITEM_STATE_CANCELED 3
> +#define BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED 4
>
> struct btrfs_dev_replace_item {
> /*
> --------------------------------------
>
>
> Thanks, Anand
>
