At Sat, 30 May 2015 18:34:23 +0900,
Hitoshi Mitake wrote:
>
> Current sheep cannot handle a case of VID overflow correctly. The main
> cause of this problem is invalid usage of fill_vdi_info_range() by
> fill_vdi_info() in a case of overflow. This patch fixes this problem.
>
> In addition, this patch lets 0x000000 be an invalid VID. It is for VID
> recycling. In some places of sheepdog, parent_vid is used as a
> value which indicates that the VDI has a parent (clone or snapshot) or
> not (working VDI). So this patch lets the first VID 0x000001 and
> prevent this sort of confusion.
>
> Signed-off-by: Hitoshi Mitake <[email protected]>
> ---
> sheep/vdi.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
Applied this series.
Thanks,
Hitoshi
>
> diff --git a/sheep/vdi.c b/sheep/vdi.c
> index 63e578d..0505d7d 100644
> --- a/sheep/vdi.c
> +++ b/sheep/vdi.c
> @@ -1345,7 +1345,7 @@ out:
> /*
> * Return SUCCESS (range of bits set):
> * Iff we get a bitmap range [left, right) that VDI might be set between. if
> - * right < start, this means a wrap around case where we should examine the
> + * right < left, this means a wrap around case where we should examine the
> * two split ranges, [left, SD_NR_VDIS - 1] and [0, right). 'Right' is the
> free
> * bit that might be used by newly created VDI.
> *
> @@ -1356,13 +1356,17 @@ static int get_vdi_bitmap_range(const char *name,
> unsigned long *left,
> unsigned long *right)
> {
> *left = sd_hash_vdi(name);
> +
> + if (unlikely(!*left))
> + *left = 1; /* 0x000000 should be skipeed */
> +
> *right = find_next_zero_bit(sys->vdi_inuse, SD_NR_VDIS, *left);
> if (*left == *right)
> return SD_RES_NO_VDI;
>
> if (*right == SD_NR_VDIS) {
> /* Wrap around */
> - *right = find_next_zero_bit(sys->vdi_inuse, SD_NR_VDIS, 0);
> + *right = find_next_zero_bit(sys->vdi_inuse, SD_NR_VDIS, 1);
> if (*right == SD_NR_VDIS)
> return SD_RES_FULL_VDI;
> }
> @@ -1404,7 +1408,7 @@ static int fill_vdi_info_range(uint32_t left, uint32_t
> right,
> ret = SD_RES_NO_MEM;
> goto out;
> }
> - for (i = right - 1; i >= left; i--) {
> + for (i = right - 1; i >= left && i; i--) {
> ret = sd_read_object(vid_to_vdi_oid(i), (char *)inode,
> SD_INODE_HEADER_SIZE, 0);
> if (ret != SD_RES_SUCCESS)
> @@ -1448,14 +1452,24 @@ static int fill_vdi_info(unsigned long left, unsigned
> long right,
> {
> int ret;
>
> + assert(left != right);
> + /*
> + * If left == right, fill_vdi_info() shouldn't called by vdi_lookup().
> + * vdi_lookup() must return SD_RES_NO_VDI to its caller.
> + */
> +
> if (left < right)
> return fill_vdi_info_range(left, right, iocb, info);
>
> - ret = fill_vdi_info_range(0, right, iocb, info);
> + if (likely(1 < right))
> + ret = fill_vdi_info_range(1, right, iocb, info);
> + else
> + ret = SD_RES_NO_VDI;
> +
> switch (ret) {
> case SD_RES_NO_VDI:
> case SD_RES_NO_TAG:
> - ret = fill_vdi_info_range(left, SD_NR_VDIS - 1, iocb, info);
> + ret = fill_vdi_info_range(left, SD_NR_VDIS, iocb, info);
> break;
> default:
> break;
> --
> 1.9.1
>
--
sheepdog mailing list
[email protected]
https://lists.wpkg.org/mailman/listinfo/sheepdog
