[PATCH 21/43] hpsa: do not check cmd_alloc return value - it cannnot return NULL

Don Brace
2015-02-21T22:20:43Z

From: Robert Elliott <elliott@hp.com>

cmd_alloc can no longer return NULL, so don't check for NULL any more
(which is unreachable code).

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
---
drivers/scsi/hpsa.c | 77 ++++++++++-----------------------------------------
1 file changed, 15 insertions(+), 62 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 604e25e..b7223e6 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -2520,11 +2520,6 @@ static int hpsa_scsi_do_inquiry(struct ctlr_info *h, unsigned char *scsi3addr,

c = cmd_alloc(h);

- if (c == NULL) {
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -ENOMEM;
- }
-
if (fill_cmd(c, HPSA_INQUIRY, h, buf, bufsize,
page, scsi3addr, TYPE_CMD)) {
rc = -1;
@@ -2553,11 +2548,6 @@ static int hpsa_bmic_ctrl_mode_sense(struct ctlr_info *h,
struct ErrorInfo *ei;

c = cmd_alloc(h);
- if (c == NULL) { /* trouble... */
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -ENOMEM;
- }
-
if (fill_cmd(c, BMIC_SENSE_CONTROLLER_PARAMETERS, h, buf, bufsize,
page, scsi3addr, TYPE_CMD)) {
rc = -1;
@@ -2575,7 +2565,7 @@ static int hpsa_bmic_ctrl_mode_sense(struct ctlr_info *h,
out:
cmd_free(h, c);
return rc;
- }
+}

static int hpsa_send_reset(struct ctlr_info *h, unsigned char *scsi3addr,
u8 reset_type, int reply_queue)
@@ -2586,10 +2576,6 @@ static int hpsa_send_reset(struct ctlr_info *h, unsigned char *scsi3addr,

c = cmd_alloc(h);

- if (c == NULL) { /* trouble... */
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -ENOMEM;
- }

/* fill_cmd can't fail here, no data buffer to map. */
(void) fill_cmd(c, HPSA_DEVICE_RESET_MSG, h, NULL, 0, 0,
@@ -2717,10 +2703,7 @@ static int hpsa_get_raid_map(struct ctlr_info *h,
struct ErrorInfo *ei;

c = cmd_alloc(h);
- if (c == NULL) {
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -ENOMEM;
- }
+
if (fill_cmd(c, HPSA_GET_RAID_MAP, h, &this_device->raid_map,
sizeof(this_device->raid_map), 0,
scsi3addr, TYPE_CMD)) {
@@ -2893,10 +2876,7 @@ static int hpsa_scsi_do_report_luns(struct ctlr_info *h, int logical,
struct ErrorInfo *ei;

c = cmd_alloc(h);
- if (c == NULL) { /* trouble... */
- dev_err(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -1;
- }
+
/* address the controller */
memset(scsi3addr, 0, sizeof(scsi3addr));
if (fill_cmd(c, logical ? HPSA_REPORT_LOG : HPSA_REPORT_PHYS, h,
@@ -3011,8 +2991,7 @@ static int hpsa_volume_offline(struct ctlr_info *h,
#define ASCQ_LUN_NOT_READY_INITIALIZING_CMD_REQ 0x02

c = cmd_alloc(h);
- if (!c)
- return 0;
+
(void) fill_cmd(c, TEST_UNIT_READY, h, NULL, 0, 0, scsi3addr, TYPE_CMD);
rc = hpsa_scsi_do_simple_cmd(h, c, DEFAULT_REPLY_QUEUE, NO_TIMEOUT);
if (rc) {
@@ -3086,8 +3065,7 @@ static int hpsa_device_supports_aborts(struct ctlr_info *h,
return 1;

c = cmd_alloc(h);
- if (!c)
- return -ENOMEM;
+
(void) fill_cmd(c, HPSA_ABORT_MSG, h, &tag, 0, 0, scsi3addr, TYPE_MSG);
(void) hpsa_scsi_do_simple_cmd(h, c, DEFAULT_REPLY_QUEUE, NO_TIMEOUT);
/* no unmap needed here because no data xfer. */
@@ -4658,10 +4636,7 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
return 0;
}
c = cmd_alloc(h);
- if (c == NULL) { /* trouble... */
- dev_err(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return SCSI_MLQUEUE_HOST_BUSY;
- }
+
if (unlikely(lockup_detected(h))) {
cmd->result = DID_NO_CONNECT << 16;
cmd_free(h, c);
@@ -4822,11 +4797,6 @@ static int wait_for_device_to_become_ready(struct ctlr_info *h,
struct CommandList *c;

c = cmd_alloc(h);
- if (!c) {
- dev_warn(&h->pdev->dev, "out of memory in "
- "wait_for_device_to_become_ready.\n");
- return IO_ERROR;
- }

/* Send test unit ready until device ready, or give up. */
while (count < HPSA_TUR_RETRY_LIMIT) {
@@ -4989,10 +4959,6 @@ static int hpsa_send_abort(struct ctlr_info *h, unsigned char *scsi3addr,
__le32 tagupper, taglower;

c = cmd_alloc(h);
- if (c == NULL) { /* trouble... */
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- return -ENOMEM;
- }

/* fill_cmd can't fail here, no buffer to map */
(void) fill_cmd(c, HPSA_ABORT_MSG, h, &abort->Header.tag,
@@ -5279,6 +5245,8 @@ static int hpsa_eh_abort_handler(struct scsi_cmnd *sc)
* and managed by cmd_alloc() and cmd_free() using a simple bitmap to track
* which ones are free or in use. Lock must be held when calling this.
* cmd_free() is the complement.
+ * This function never gives up and returns NULL. If it hangs,
+ * another thread must call cmd_free() to free some tags.
*/

static struct CommandList *cmd_alloc(struct ctlr_info *h)
@@ -5512,10 +5480,7 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h, void __user *argp)
}
}
c = cmd_alloc(h);
- if (c == NULL) {
- rc = -ENOMEM;
- goto out_kfree;
- }
+
/* Fill in the command type */
c->cmd_type = CMD_IOCTL_PEND;
/* Fill in Command Header */
@@ -5649,10 +5614,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
sg_used++;
}
c = cmd_alloc(h);
- if (c == NULL) {
- status = -ENOMEM;
- goto cleanup1;
- }
+
c->cmd_type = CMD_IOCTL_PEND;
c->Header.ReplyQueue = 0;
c->Header.SGList = (u8) sg_used;
@@ -5768,14 +5730,13 @@ static int hpsa_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
}
}

-static int hpsa_send_host_reset(struct ctlr_info *h, unsigned char *scsi3addr,
+static void hpsa_send_host_reset(struct ctlr_info *h, unsigned char *scsi3addr,
u8 reset_type)
{
struct CommandList *c;

c = cmd_alloc(h);
- if (!c)
- return -ENOMEM;
+
/* fill_cmd can't fail here, no data buffer to map */
(void) fill_cmd(c, HPSA_DEVICE_RESET_MSG, h, NULL, 0, 0,
RAID_CTLR_LUNID, TYPE_MSG);
@@ -5786,7 +5747,7 @@ static int hpsa_send_host_reset(struct ctlr_info *h, unsigned char *scsi3addr,
* the command either. This is the last command we will send before
* re-initializing everything, so it doesn't matter and won't leak.
*/
- return 0;
+ return;
}

static int fill_cmd(struct CommandList *c, u8 cmd, struct ctlr_info *h,
@@ -7188,11 +7149,7 @@ static int hpsa_request_irqs(struct ctlr_info *h,

static int hpsa_kdump_soft_reset(struct ctlr_info *h)
{
- if (hpsa_send_host_reset(h, RAID_CTLR_LUNID,
- HPSA_RESET_TYPE_CONTROLLER)) {
- dev_warn(&h->pdev->dev, "Resetting array controller failed.\n");
- return -EIO;
- }
+ hpsa_send_host_reset(h, RAID_CTLR_LUNID, HPSA_RESET_TYPE_CONTROLLER);

dev_info(&h->pdev->dev, "Waiting for board to soft reset.\n");
if (hpsa_wait_for_board_state(h->pdev, h->vaddr, BOARD_NOT_READY)) {
@@ -7696,10 +7653,7 @@ static void hpsa_flush_cache(struct ctlr_info *h)
return;

c = cmd_alloc(h);
- if (!c) {
- dev_warn(&h->pdev->dev, "cmd_alloc returned NULL!\n");
- goto out_of_memory;
- }
+
if (fill_cmd(c, HPSA_CACHE_FLUSH, h, flush_buf, 4, 0,
RAID_CTLR_LUNID, TYPE_CMD)) {
goto out;
@@ -7713,7 +7667,6 @@ out:
dev_warn(&h->pdev->dev,
"error flushing cache on controller\n");
cmd_free(h, c);
-out_of_memory:
kfree(flush_buf);
}