| Message ID | 20200724171706.1550403-5-tasleson@redhat.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | Add persistent durable identifier to storage log messages | expand |
On Fri, Jul 24, 2020 at 8:19 PM Tony Asleson <tasleson@redhat.com> wrote: > > Add the needed functions to fill out the durable_name function > call back for scsi based storage devices. This allows calls > into dev_printk for scsi devices to have a persistent id > associated with them. ... > +int scsi_durable_name(struct scsi_device *sdev, char *buf, size_t len) > +{ > + int vpd_len = 0; What is the purpose of the assignment? > + vpd_len = scsi_vpd_lun_id(sdev, buf, len); > + if (vpd_len > 0 && vpd_len < len) > + vpd_len++; > + else > + vpd_len = 0; > + > + return vpd_len; int vpd_len; vpd_len = ...(...); if (vpd_len ...) return vpd_len + 1; return 0; > +} ... > }; > > + One blank line is enough. > +int dev_to_scsi_durable_name(const struct device *dev, char *buf, size_t len) > +{ > + struct scsi_device *sd_dev = NULL; Redundant assignment. > + // When we go through dev_printk in the scsi layer, dev is embedded > + // in a struct scsi_device. When we go through the block layer, > + // dev is embedded in struct genhd, thus we need different paths to > + // retrieve the struct scsi_device to call scsi_durable_name. > + if (dev->type == &scsi_dev_type) { > + sd_dev = to_scsi_device(dev); This... > + } else if (dev->parent && dev->parent->type == &scsi_dev_type) { > + sd_dev = to_scsi_device(dev->parent); ...and this along with pieces in scsi_bus_uevent(), scsi_bus_match() are candidates for a good helper (perhaps with utilization of scsi_is_sdev_device(), but maybe not necessary). static struct scsi_device *dev_to_scsi_device(struct device *dev) { return dev->type == &scsi_dev_type ? to_scsi_device(dev) : NULL; } sdev = dev_to_scsi_device(dev); if (!sdev) sdev = dev_to_scsi_device(dev->parent); if (!sdev) return 0; And when introducing a helper change users at the same time. > + } else { > + // We have a pointer to something else, bail > + return 0; > + } > + > + return scsi_durable_name(sd_dev, buf, len); > +}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 06c260f6cdae..9f6c41162c55 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -3142,3 +3142,17 @@ int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) return group_id; } EXPORT_SYMBOL(scsi_vpd_tpg_id); + +int scsi_durable_name(struct scsi_device *sdev, char *buf, size_t len) +{ + int vpd_len = 0; + + vpd_len = scsi_vpd_lun_id(sdev, buf, len); + if (vpd_len > 0 && vpd_len < len) + vpd_len++; + else + vpd_len = 0; + + return vpd_len; +} +EXPORT_SYMBOL(scsi_durable_name); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 163dbcb741c1..f719b63f4b63 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1582,6 +1582,28 @@ static struct device_type scsi_dev_type = { .groups = scsi_sdev_attr_groups, }; + +int dev_to_scsi_durable_name(const struct device *dev, char *buf, size_t len) +{ + struct scsi_device *sd_dev = NULL; + + // When we go through dev_printk in the scsi layer, dev is embedded + // in a struct scsi_device. When we go through the block layer, + // dev is embedded in struct genhd, thus we need different paths to + // retrieve the struct scsi_device to call scsi_durable_name. + if (dev->type == &scsi_dev_type) { + sd_dev = to_scsi_device(dev); + } else if (dev->parent && dev->parent->type == &scsi_dev_type) { + sd_dev = to_scsi_device(dev->parent); + } else { + // We have a pointer to something else, bail + return 0; + } + + return scsi_durable_name(sd_dev, buf, len); +} +EXPORT_SYMBOL(dev_to_scsi_durable_name); + void scsi_sysfs_device_initialize(struct scsi_device *sdev) { unsigned long flags; @@ -1591,6 +1613,7 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev) device_initialize(&sdev->sdev_gendev); sdev->sdev_gendev.bus = &scsi_bus_type; sdev->sdev_gendev.type = &scsi_dev_type; + sdev->sdev_gendev.durable_name = dev_to_scsi_durable_name; dev_set_name(&sdev->sdev_gendev, "%d:%d:%d:%llu", sdev->host->host_no, sdev->channel, sdev->id, sdev->lun); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index a793cb08d025..f40e4cb4a5f6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3360,6 +3360,8 @@ static int sd_probe(struct device *dev) gd->private_data = &sdkp->driver; gd->queue = sdkp->device->request_queue; + disk_to_dev(gd)->durable_name = dev_to_scsi_durable_name; + /* defaults, until the device tells us otherwise */ sdp->sector_size = 512; sdkp->capacity = 0; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index c3cba2aaf934..7be5861565f7 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -461,6 +461,9 @@ extern void sdev_disable_disk_events(struct scsi_device *sdev); extern void sdev_enable_disk_events(struct scsi_device *sdev); extern int scsi_vpd_lun_id(struct scsi_device *, char *, size_t); extern int scsi_vpd_tpg_id(struct scsi_device *, int *); +extern int dev_to_scsi_durable_name(const struct device *dev, char *buf, + size_t len); +extern int scsi_durable_name(struct scsi_device *sdev, char *buf, size_t len); #ifdef CONFIG_PM extern int scsi_autopm_get_device(struct scsi_device *);
Add the needed functions to fill out the durable_name function call back for scsi based storage devices. This allows calls into dev_printk for scsi devices to have a persistent id associated with them. Signed-off-by: Tony Asleson <tasleson@redhat.com> --- drivers/scsi/scsi_lib.c | 14 ++++++++++++++ drivers/scsi/scsi_sysfs.c | 23 +++++++++++++++++++++++ drivers/scsi/sd.c | 2 ++ include/scsi/scsi_device.h | 3 +++ 4 files changed, 42 insertions(+)