On 10 September 2015 at 10:43, Jon Hunter <jonath...@nvidia.com> wrote: > Hi Ulf, > > On 09/09/15 13:42, Ulf Hansson wrote: > > [snip] > >>> +static int mmc_blk_ioctl_cmd(struct block_device *bdev, >>> + struct mmc_ioc_cmd __user *ic_ptr) >>> +{ >>> + struct mmc_blk_ioc_data *idata; >>> + struct mmc_blk_data *md; >>> + struct mmc_card *card; >>> + int err; >>> + >>> + /* >>> + * The caller must have CAP_SYS_RAWIO, and must be calling this on >>> the >>> + * whole block device, not on a partition. This prevents overspray >>> + * between sibling partitions. >>> + */ >>> + if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) >>> + return -EPERM; >>> + >>> + idata = mmc_blk_ioctl_copy_from_user(ic_ptr); >>> + if (IS_ERR(idata)) >>> + return PTR_ERR(idata); >>> + >>> + md = mmc_blk_get(bdev->bd_disk); >>> + if (!md) { >>> + err = -EINVAL; >>> + goto cmd_err; >>> + } >>> + >>> + card = md->queue.card; >>> + if (IS_ERR(card)) { >>> + err = PTR_ERR(card); >>> + goto cmd_done; >>> + } >>> + >>> + mmc_claim_host(card->host); >> >> As __mmc_blk_ioctl_cmd() already does mmc_get_card(), you don't need >> mmc_claim_host() here. > > Thinking about this some more, does it make sense to have a > mmc_get_card() above and then remove the one from __mmc_blk_ioctl_cmd()? > The mmc_blk_ioctl_multi_cmd() needs to call mmc_get_card() before > calling __mmc_blk_ioctl_cmd() and so currently we are calling > mmc_get_card() twice in the case of mmc_blk_ioctl_multi_cmd() which > seems unnecessary.
I agree. We can follow your suggestion, but then we also need to add mmc_get|put_card() in the case for non-multi commands. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/