[PATCH RESEND v2 01/11] scsi: scsi_debug: Don't hold driver host struct pointer in host->hostdata[]

John Garry posted 11 patches 2 years, 11 months ago
[PATCH RESEND v2 01/11] scsi: scsi_debug: Don't hold driver host struct pointer in host->hostdata[]
Posted by John Garry 2 years, 11 months ago
This driver stores just a pointer to the driver host structure in
host->hostdata[]. Most other drivers actually have the driver host
structure allocated in host->hostdata[], but this driver is different as
we allocate that memory separately before allocating the shost memory.

However there is no need to allocate this memory only in host->hostdata[]
when we can already look up the driver host structure from shost->dma_dev,
so add a macro for this - shost_to_sdebug_host(). Rename to_sdebug_host()
-> dev_to_sdebug_host() to avoid ambiguity.

Also remove a check for !sdbg_host in find_build_dev_info(), as this cannot
be true. Other similar checks will be later removed.

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 drivers/scsi/scsi_debug.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 72149eeee6e6..554c03d7a648 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -324,9 +324,12 @@ struct sdeb_store_info {
 	void *map_storep;	/* provisioning map */
 };
 
-#define to_sdebug_host(d)	\
+#define dev_to_sdebug_host(d)	\
 	container_of(d, struct sdebug_host_info, dev)
 
+#define shost_to_sdebug_host(shost)	\
+	dev_to_sdebug_host(shost->dma_dev)
+
 enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1,
 		      SDEB_DEFER_WQ = 2, SDEB_DEFER_POLL = 3};
 
@@ -5166,11 +5169,7 @@ static struct sdebug_dev_info *find_build_dev_info(struct scsi_device *sdev)
 	struct sdebug_dev_info *open_devip = NULL;
 	struct sdebug_dev_info *devip;
 
-	sdbg_host = *(struct sdebug_host_info **)shost_priv(sdev->host);
-	if (!sdbg_host) {
-		pr_err("Host info NULL\n");
-		return NULL;
-	}
+	sdbg_host = shost_to_sdebug_host(sdev->host);
 
 	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
 		if ((devip->used) && (devip->channel == sdev->channel) &&
@@ -5407,7 +5406,7 @@ static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)
 	hp = sdp->host;
 	if (!hp)
 		goto lie;
-	sdbg_host = *(struct sdebug_host_info **)shost_priv(hp);
+	sdbg_host = shost_to_sdebug_host(hp);
 	if (sdbg_host) {
 		list_for_each_entry(devip,
 				    &sdbg_host->dev_info_list,
@@ -5440,7 +5439,7 @@ static int scsi_debug_bus_reset(struct scsi_cmnd *SCpnt)
 		sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
 	hp = sdp->host;
 	if (hp) {
-		sdbg_host = *(struct sdebug_host_info **)shost_priv(hp);
+		sdbg_host = shost_to_sdebug_host(hp);
 		if (sdbg_host) {
 			list_for_each_entry(devip,
 					    &sdbg_host->dev_info_list,
@@ -7165,7 +7164,7 @@ static void sdebug_release_adapter(struct device *dev)
 {
 	struct sdebug_host_info *sdbg_host;
 
-	sdbg_host = to_sdebug_host(dev);
+	sdbg_host = dev_to_sdebug_host(dev);
 	kfree(sdbg_host);
 }
 
@@ -7812,14 +7811,14 @@ static int sdebug_driver_probe(struct device *dev)
 	struct Scsi_Host *hpnt;
 	int hprot;
 
-	sdbg_host = to_sdebug_host(dev);
+	sdbg_host = dev_to_sdebug_host(dev);
 
 	sdebug_driver_template.can_queue = sdebug_max_queue;
 	sdebug_driver_template.cmd_per_lun = sdebug_max_queue;
 	if (!sdebug_clustering)
 		sdebug_driver_template.dma_boundary = PAGE_SIZE - 1;
 
-	hpnt = scsi_host_alloc(&sdebug_driver_template, sizeof(sdbg_host));
+	hpnt = scsi_host_alloc(&sdebug_driver_template, 0);
 	if (NULL == hpnt) {
 		pr_err("scsi_host_alloc failed\n");
 		error = -ENODEV;
@@ -7862,7 +7861,6 @@ static int sdebug_driver_probe(struct device *dev)
 		hpnt->nr_maps = 3;
 
 	sdbg_host->shost = hpnt;
-	*((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host;
 	if ((hpnt->this_id >= 0) && (sdebug_num_tgts > hpnt->this_id))
 		hpnt->max_id = sdebug_num_tgts + 1;
 	else
@@ -7936,7 +7934,7 @@ static void sdebug_driver_remove(struct device *dev)
 	struct sdebug_host_info *sdbg_host;
 	struct sdebug_dev_info *sdbg_devinfo, *tmp;
 
-	sdbg_host = to_sdebug_host(dev);
+	sdbg_host = dev_to_sdebug_host(dev);
 
 	scsi_remove_host(sdbg_host->shost);
 
-- 
2.35.3
Re: [PATCH RESEND v2 01/11] scsi: scsi_debug: Don't hold driver host struct pointer in host->hostdata[]
Posted by Douglas Gilbert 2 years, 11 months ago
On 2023-03-13 05:31, John Garry wrote:
> This driver stores just a pointer to the driver host structure in
> host->hostdata[]. Most other drivers actually have the driver host
> structure allocated in host->hostdata[], but this driver is different as
> we allocate that memory separately before allocating the shost memory.
> 
> However there is no need to allocate this memory only in host->hostdata[]
> when we can already look up the driver host structure from shost->dma_dev,
> so add a macro for this - shost_to_sdebug_host(). Rename to_sdebug_host()
> -> dev_to_sdebug_host() to avoid ambiguity.
> 
> Also remove a check for !sdbg_host in find_build_dev_info(), as this cannot
> be true. Other similar checks will be later removed.
> 
> Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>

Please apply my "ack" to the rest of this series (2 through 11).

Good the have other eyes looking at this driver and making
improvements.

Thanks
Doug Gilbert
Re: [PATCH RESEND v2 01/11] scsi: scsi_debug: Don't hold driver host struct pointer in host->hostdata[]
Posted by John Garry 2 years, 11 months ago
On 14/03/2023 02:34, Douglas Gilbert wrote:
> 2023-03-13 05:31, John Garry wrote:
>> This driver stores just a pointer to the driver host structure in
>> host->hostdata[]. Most other drivers actually have the driver host
>> structure allocated in host->hostdata[], but this driver is different as
>> we allocate that memory separately before allocating the shost memory.
>>
>> However there is no need to allocate this memory only in host->hostdata[]
>> when we can already look up the driver host structure from 
>> shost->dma_dev,
>> so add a macro for this - shost_to_sdebug_host(). Rename to_sdebug_host()
>> -> dev_to_sdebug_host() to avoid ambiguity.
>>
>> Also remove a check for !sdbg_host in find_build_dev_info(), as this 
>> cannot
>> be true. Other similar checks will be later removed.
>>
>> Signed-off-by: John Garry <john.g.garry@oracle.com>
> Acked-by: Douglas Gilbert <dgilbert@interlog.com>
> 
> Please apply my "ack" to the rest of this series (2 through 11).
> 

Thanks.

Hi Martin, Please let me know if you would like me to send the series 
again with Doug's tags appended.

> Good the have other eyes looking at this driver and making
> improvements.

No worries, Please check the other series which I sent when you can. I 
am not sure how to solve the issue related to the last patch there. 
Maybe a solution would be to just remove all the shosts and then re-add 
with updated can_queue.

John