[PATCH v8 16/19] scsi: scsi_debug: Allocate the MODE SENSE response from the heap

Bart Van Assche
2023-12-19T00:09:02Z

Make the MODE SENSE response buffer larger and allocate it from the heap.
This patch prepares for adding support for the IO Advice Hints Grouping
mode page.

Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/scsi_debug.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index cadd130d6b53..4181d0d81224 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -43,6 +43,7 @@
#include <linux/prefetch.h>
#include <linux/debugfs.h>
#include <linux/async.h>
+#include <linux/cleanup.h>

#include <net/checksum.h>

@@ -2637,7 +2638,8 @@ static int resp_sas_sha_m_spg(unsigned char *p, int pcontrol)
return sizeof(sas_sha_m_pg);
}

-#define SDEBUG_MAX_MSENSE_SZ 256
+/* PAGE_SIZE is more than necessary but provides room for future expansion. */
+#define SDEBUG_MAX_MSENSE_SZ PAGE_SIZE

static int resp_mode_sense(struct scsi_cmnd *scp,
struct sdebug_dev_info *devip)
@@ -2648,10 +2650,13 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
int target_dev_id;
int target = scp->device->id;
unsigned char *ap;
- unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
+ unsigned char *arr __free(kfree);
unsigned char *cmd = scp->cmnd;
bool dbd, llbaa, msense_6, is_disk, is_zbc;

+ arr = kzalloc(SDEBUG_MAX_MSENSE_SZ, GFP_ATOMIC);
+ if (!arr)
+ return -ENOMEM;
dbd = !!(cmd[1] & 0x8); /* disable block descriptors */
pcontrol = (cmd[2] & 0xc0) >> 6;
pcode = cmd[2] & 0x3f;