[libvirt] [PATCH 5/9] nodedev: Refactor the helpers

[Michal Privoznik]

On 14.01.2013 15:34, Osier Yang wrote:
> This adds two util functions (virIsCapableFCHost and virIsCapableVport),
> and rename helper check_fc_host_linux as detect_scsi_host_caps,
> check_capable_vport_linux is removed, as it's abstracted to the util
> function virIsCapableVport. detect_scsi_host_caps nows detect both
> the fc_host and vport_ops capabilities. "stat(2)" is replaced with
> "access(2)" for saving.
> 
> * src/util/virutil.h:
>   - Declare virIsCapableFCHost and virIsCapableVport
> * src/util/virutil.c:
>   - Implement virIsCapableFCHost and virIsCapableVport
> * src/node_device/node_device_linux_sysfs.c:
>   - Remove check_capable_vport_linux
>   - Rename check_fc_host_linux as detect_scsi_host_caps, and refactor
>     it a bit to detect both fc_host and vport_os capabilities
> * src/node_device/node_device_driver.h:
>   - Change/remove the related declarations
> * src/node_device/node_device_udev.c: (Use detect_scsi_host_caps)
> * src/node_device/node_device_hal.c: (Likewise)
> * src/node_device/node_device_driver.c (Likewise)
> ---
>  src/libvirt_private.syms                  |    2 +
>  src/node_device/node_device_driver.c      |    7 +-
>  src/node_device/node_device_driver.h      |   10 +--
>  src/node_device/node_device_hal.c         |    4 +-
>  src/node_device/node_device_linux_sysfs.c |  135 ++++++++---------------------
>  src/node_device/node_device_udev.c        |    3 +-
>  src/util/virutil.c                        |   73 ++++++++++++++++
>  src/util/virutil.h                        |    3 +
>  8 files changed, 123 insertions(+), 114 deletions(-)
> 

> diff --git a/src/node_device/node_device_linux_sysfs.c b/src/node_device/node_device_linux_sysfs.c
> index 742a0bc..054afea 100644
> --- a/src/node_device/node_device_linux_sysfs.c
> +++ b/src/node_device/node_device_linux_sysfs.c
> @@ -1,8 +1,8 @@
>  /*
> - * node_device_hal_linuc.c: Linux specific code to gather device data
> + * node_device_linux_sysfs.c: Linux specific code to gather device data
>   * not available through HAL.
>   *
> - * Copyright (C) 2009-2011 Red Hat, Inc.
> + * Copyright (C) 2009-2013 Red Hat, Inc.
>   *
>   * This library is free software; you can redistribute it and/or
>   * modify it under the terms of the GNU Lesser General Public
> @@ -37,112 +37,53 @@
>  
>  #ifdef __linux__
>  
> -int check_fc_host_linux(union _virNodeDevCapData *d)
> +int
> +detect_scsi_host_caps_linux(union _virNodeDevCapData *d)
>  {
> -    char *sysfs_path = NULL;
> -    int retval = 0;
> -    struct stat st;
> +    int ret = -1;
>  
>      VIR_DEBUG("Checking if host%d is an FC HBA", d->scsi_host.host);
>  
> -    if (virAsprintf(&sysfs_path, "%shost%d",
> -                    LINUX_SYSFS_FC_HOST_PREFIX,
> -                    d->scsi_host.host) < 0) {
> -        virReportOOMError();
> -        retval = -1;
> -        goto out;
> +    if (virIsCapableFCHost(NULL, d->scsi_host.host)) {
> +        d->scsi_host.flags |= VIR_NODE_DEV_CAP_FLAG_HBA_FC_HOST;
> +
> +        if (virReadFCHost(NULL,
> +                          d->scsi_host.host,
> +                          "port_name",
> +                          &d->scsi_host.wwpn) == -1) {
> +            VIR_ERROR(_("Failed to read WWPN for host%d"), d->scsi_host.host);
> +            goto cleanup;
> +        }
> +
> +        if (virReadFCHost(NULL,
> +                          d->scsi_host.host,
> +                          "node_name",
> +                          &d->scsi_host.wwnn) == -1) {
> +            VIR_ERROR(_("Failed to read WWNN for host%d"), d->scsi_host.host);
> +            goto cleanup;
> +        }
> +
> +        if (virReadFCHost(NULL,
> +                          d->scsi_host.host,
> +                          "fabric_name",
> +                          &d->scsi_host.fabric_wwn) == -1) {
> +            VIR_ERROR(_("Failed to read fabric WWN for host%d"),
> +                      d->scsi_host.host);
> +            goto cleanup;
> +        }
>      }
>  
> -    if (stat(sysfs_path, &st) != 0) {
> -        /* Not an FC HBA; not an error, either. */
> -        goto out;
> -    }
> -
> -    d->scsi_host.flags |= VIR_NODE_DEV_CAP_FLAG_HBA_FC_HOST;
> -
> -    if (virReadFCHost(NULL,
> -                      d->scsi_host.host,
> -                      "port_name",
> -                      &d->scsi_host.wwpn) == -1) {
> -        VIR_ERROR(_("Failed to read WWPN for host%d"),
> -                  d->scsi_host.host);
> -        retval = -1;
> -        goto out;
> -    }
> -
> -    if (virReadFCHost(NULL,
> -                      d->scsi_host.host,
> -                      "node_name",
> -                      &d->scsi_host.wwnn) == -1) {
> -        VIR_ERROR(_("Failed to read WWNN for host%d"),
> -                  d->scsi_host.host);
> -        retval = -1;
> -    }
> -
> -    if (virReadFCHost(NULL,
> -                      d->scsi_host.host,
> -                      "fabric_name",
> -                      &d->scsi_host.fabric_wwn) == -1) {
> -        VIR_ERROR(_("Failed to read fabric WWN for host%d"),
> -                  d->scsi_host.host);
> -        retval = -1;
> -        goto out;
> -    }
> +    if (virIsCapableVport(NULL, d->scsi_host.host) == 0)
> +        d->scsi_host.flags |= VIR_NODE_DEV_CAP_FLAG_HBA_VPORT_OPS;
>  
> -out:
> -    if (retval == -1) {
> +    ret = 0;
> +cleanup:
> +    if (ret == -1) {

I'd write this as 'if (ret < 0) {' so we don't have to change this line
if we ever invent a new error code for this function. Moreover, it's
common practice over libvirt code.

ACK if you fix this.

Michal