On Wed, Jun 14, 2023 at 12:20:39PM +0200, Ulf Hansson wrote:
On Tue, 13 Jun 2023 at 14:43, Christian Loehle CLoehle@hyperstone.com wrote:
commit 003fb0a51162d940f25fc35e70b0996a12c9e08a upstream.
Requests to the mmc layer usually come through a block device IO. The exceptions are the ioctl interface, RPMB chardev ioctl and debugfs, which issue their own blk_mq requests through blk_execute_rq and do not query the BLK_STS error but the mmcblk-internal drv_op_result. This patch ensures that drv_op_result defaults to an error and has to be overwritten by the operation to be considered successful.
The behavior leads to a bug where the request never propagates the error, e.g. by directly erroring out at mmc_blk_mq_issue_rq if mmc_blk_part_switch fails. The ioctl caller of the rpmb chardev then can never see an error (BLK_STS_IOERR, but drv_op_result is unchanged) and thus may assume that their call executed successfully when it did not.
While always checking the blk_execute_rq return value would be advised, let's eliminate the error by always setting drv_op_result as -EIO to be overwritten on success (or other error)
Fixes: 614f0388f580 ("mmc: block: move single ioctl() commands to block requests") Signed-off-by: Christian Loehle cloehle@hyperstone.com
Acked-by: Ulf Hansson ulf.hansson@linaro.org
All now queued up, thanks.
greg k-h