On Tue, 2018-08-07 at 16:26 -0600, Keith Busch wrote:
> A user space rule saves the unsafe shutdown count to a fixed location
> for Intel dimms so that non-root users can read it. If the smart command
> submission fails, this patch uses that saved value in a newly added
> ndctl_cmd "handle_error" callback. If the cached value is available,
> the error handler will override the command status to success, and set
> the valid flags for the shutdown count.
>
> Signed-off-by: Keith Busch <[email protected]>
> ---
> ndctl/lib/intel.c | 34 +++++++++++++++++++++++++++++++++-
> ndctl/lib/libndctl.c | 2 ++
> ndctl/lib/private.h | 1 +
> 3 files changed, 36 insertions(+), 1 deletion(-)
Looks good to me!
>
> diff --git a/ndctl/lib/intel.c b/ndctl/lib/intel.c
> index 0abea1e..83f8203 100644
> --- a/ndctl/lib/intel.c
> +++ b/ndctl/lib/intel.c
> @@ -56,6 +56,38 @@ static struct ndctl_cmd *alloc_intel_cmd(struct ndctl_dimm
> *dimm,
> return cmd;
> }
>
> +/*
> + * If provided, read the cached shutdown count in case the user does not have
> + * access rights to run the smart command, and pretend the command was
> + * successful with only the shutdown_count valid.
> + */
> +static int intel_smart_handle_error(struct ndctl_cmd *cmd)
> +{
> + struct ndctl_dimm *dimm = cmd->dimm;
> + char *path = NULL, shutdown_count[16] = {};
> + int fd, rc = cmd->status;
> +
> + if (asprintf(&path, DEF_TMPFS_DIR "/%s/usc",
> + ndctl_dimm_get_unique_id(dimm)) < 0)
> + return rc;
> +
> + fd = open(path, O_RDONLY);
> + if (fd < 0)
> + goto free_path;
> +
> + if (read(fd, shutdown_count, sizeof(shutdown_count)) < 0)
> + goto close;
> +
> + cmd->intel->smart.flags = ND_INTEL_SMART_SHUTDOWN_COUNT_VALID;
> + cmd->intel->smart.shutdown_count = strtoull(shutdown_count, NULL, 0);
> + rc = cmd->status = 0;
> + close:
> + close (fd);
> + free_path:
> + free(path);
> + return rc;
> +}
> +
> static struct ndctl_cmd *intel_dimm_cmd_new_smart(struct ndctl_dimm *dimm)
> {
> struct ndctl_cmd *cmd;
> @@ -67,7 +99,7 @@ static struct ndctl_cmd *intel_dimm_cmd_new_smart(struct
> ndctl_dimm *dimm)
> if (!cmd)
> return NULL;
> cmd->firmware_status = &cmd->intel->smart.status;
> -
> + cmd->handle_error = intel_smart_handle_error;
> return cmd;
> }
>
> diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
> index 47e005e..d94321e 100644
> --- a/ndctl/lib/libndctl.c
> +++ b/ndctl/lib/libndctl.c
> @@ -2651,6 +2651,8 @@ NDCTL_EXPORT int ndctl_cmd_submit(struct ndctl_cmd *cmd)
> close(fd);
> out:
> cmd->status = rc;
> + if (rc && cmd->handle_error)
> + rc = cmd->handle_error(cmd);
> return rc;
> }
>
> diff --git a/ndctl/lib/private.h b/ndctl/lib/private.h
> index a94f894..5812c85 100644
> --- a/ndctl/lib/private.h
> +++ b/ndctl/lib/private.h
> @@ -255,6 +255,7 @@ struct ndctl_cmd {
> int dir;
> } iter;
> struct ndctl_cmd *source;
> + int (*handle_error)(struct ndctl_cmd *cmd);
> union {
> struct nd_cmd_ars_cap ars_cap[0];
> struct nd_cmd_ars_start ars_start[0];
_______________________________________________
Linux-nvdimm mailing list
[email protected]
https://lists.01.org/mailman/listinfo/linux-nvdimm
