Using scsi_device_from_queue(), return the scsi_disk structure
associated with a request queue if the device is a disk.
Export this function to make it available to modules.
Signed-off-by: Damien Le Moal <damien.lem...@wdc.com>
---
drivers/scsi/sd.c | 32 ++++++++++++++++++++++++++++++++
drivers/scsi/sd.h | 2 ++
2 files changed, 34 insertions(+)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 1cd113df2d3a..ff9fff4de3e6 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -631,6 +631,38 @@ static void scsi_disk_put(struct scsi_disk *sdkp)
mutex_unlock(&sd_ref_mutex);
}
+static int scsi_disk_lookup(struct device *dev, void *data)
+{
+ struct scsi_disk **sdkp = data;
+
+ if (!*sdkp && dev->class == &sd_disk_class)
+ *sdkp = to_scsi_disk(dev);
+
+ return 0;
+}
+
+/**
+ * scsi_disk_from_queue - return scsi disk associated with a request_queue
+ * @q: The request queue to return the scsi disk from
+ *
+ * Return the struct scsi_disk associated with a request queue or NULL if the
+ * request_queue does not reference a SCSI device or a if the device is
+ * not a disk.
+ */
+struct scsi_disk *scsi_disk_from_queue(struct request_queue *q)
+{
+ struct scsi_device *sdev = scsi_device_from_queue(q);
+ struct scsi_disk *sdkp = NULL;
+
+ if (!sdev)
+ return NULL;
+
+ device_for_each_child(&sdev->sdev_gendev, &sdkp, scsi_disk_lookup);
+
+ return sdkp;
+}
+EXPORT_SYMBOL_GPL(scsi_disk_from_queue);
+
#ifdef CONFIG_BLK_SED_OPAL
static int sd_sec_submit(void *data, u16 spsp, u8 secp, void *buffer,
size_t len, bool send)
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 3ea82c8cecd5..92113a9e2b20 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -126,6 +126,8 @@ static inline struct scsi_disk *scsi_disk(struct gendisk
*disk)
return container_of(disk->private_data, struct scsi_disk, driver);
}
+struct scsi_disk *scsi_disk_from_queue(struct request_queue *q);
+
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_prefix_printk(prefix, (sdsk)->device, \
--
2.13.5
