Colin Lord <cl...@redhat.com> writes:
> Returns negative error codes and accompanying error messages in cases where
> the device has no tray or the tray is locked and isn't forced open. This
> extra information should result in better flexibility in functions that
> call do_open_tray.
>
> Signed-off-by: Colin Lord <cl...@redhat.com>
> ---
> v2: fix function documentation, improve commit wording, and remove
> unnecessary null check
> blockdev.c | 36 +++++++++++++++++++++---------------
> 1 file changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/blockdev.c b/blockdev.c
> index 717785e..d50a2a5 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2286,17 +2286,14 @@ void qmp_eject(const char *device, bool has_force,
> bool force, Error **errp)
> }
>
> rc = do_open_tray(device, force, &local_err);
> - if (local_err) {
> + if (rc == -ENOSYS) {
> + error_free(local_err);
> + local_err = NULL;
> + } else if (local_err) {
> error_propagate(errp, local_err);
> return;
> }
I like to put the error case in a conditional, and leave the normal flow
unindented, because it makes the normal flow easier to follow:
if (rc && rc != -ENOSYS) {
error_propagate(errp, local_err);
return;
}
error_free(local_err);
error_free(NULL) is safe.
>
> - if (rc == EINPROGRESS) {
> - error_setg(errp, "Device '%s' is locked and force was not specified,
> "
> - "wait for tray to open and try again", device);
> - return;
> - }
> -
> qmp_x_blockdev_remove_medium(device, errp);
> }
>
> @@ -2325,10 +2322,9 @@ void qmp_block_passwd(bool has_device, const char
> *device,
> }
>
> /**
> - * returns -errno on fatal error, +errno for non-fatal situations.
> - * errp will always be set when the return code is negative.
> - * May return +ENOSYS if the device has no tray,
> - * or +EINPROGRESS if the tray is locked and the guest has been notified.
> + * returns -errno on all errors, and errp will be set on error
> + * May return the non-fatal error codes -ENOSYS if the device has no tray,
> + * or -EINPROGRESS if the tray is locked and the guest has been notified.
> */
What does the function do?
What does it return on success?
Suggest imperative mood.
Here's my try:
/*
* Attempt to open the tray of @device.
* If @force, ignore its tray lock.
* Else, if the tray is locked, don't open it, but ask the guest to
* open it.
* On error, store an error through @errp and return -errno.
* If @device does not exist, return -ENODEV.
* If it has no removable media, return -ENOTSUP.
* If it has no tray, return -ENOSYS.
* If the guest was asked to open the tray, return -EINPROGRESS.
* Else, return 0.
*/
> static int do_open_tray(const char *device, bool force, Error **errp)
> {
> @@ -2348,8 +2344,8 @@ static int do_open_tray(const char *device, bool force,
> Error **errp)
> }
>
> if (!blk_dev_has_tray(blk)) {
> - /* Ignore this command on tray-less devices */
> - return ENOSYS;
> + error_setg(errp, "Device '%s' does not have a tray", device);
> + return -ENOSYS;
> }
>
> if (blk_dev_is_tray_open(blk)) {
> @@ -2366,7 +2362,9 @@ static int do_open_tray(const char *device, bool force,
> Error **errp)
> }
>
> if (locked && !force) {
> - return EINPROGRESS;
> + error_setg(errp, "Device '%s' is locked and force was not specified,
> "
> + "wait for tray to open and try again", device);
> + return -EINPROGRESS;
> }
>
> return 0;
> @@ -2375,10 +2373,18 @@ static int do_open_tray(const char *device, bool
> force, Error **errp)
> void qmp_blockdev_open_tray(const char *device, bool has_force, bool force,
> Error **errp)
> {
> + Error *local_err = NULL;
> + int rc;
> +
> if (!has_force) {
> force = false;
> }
> - do_open_tray(device, force, errp);
> + rc = do_open_tray(device, force, &local_err);
> + if (rc == -EINPROGRESS || rc == -ENOSYS) {
> + error_free(local_err);
> + } else {
> + error_propagate(errp, local_err);
> + }
> }
Likewise:
if (rc && rc != -ENOSYS && rc != EINPROGRESS) {
error_propagate(errp, local_err);
return;
}
error_free(local_err);
>
> void qmp_blockdev_close_tray(const char *device, Error **errp)
While you're cleaning up: mind moving the forward declaration of
do_open_tray() to the beginning?
