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authorJens Axboe <jens.axboe@oracle.com>2008-11-20 09:46:09 +0100
committerJens Axboe <jens.axboe@oracle.com>2008-12-29 08:28:43 +0100
commit8a3173de4ab4cdacc43675dc5c077f9a5bf17f5f (patch)
treee1998a856a09c805c588740c8c83d50dd9663c40
parent7c0990c7ee988aa193abbb7da3faeb9279146dbf (diff)
cciss: switch to using hlist for command list management
This both cleans up the code and also helps detect the spurious case of a command attempted being removed from a queue it doesn't belong to. Acked-by: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--drivers/block/cciss.c72
-rw-r--r--drivers/block/cciss.h4
-rw-r--r--drivers/block/cciss_cmd.h3
3 files changed, 33 insertions, 46 deletions
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 9f7c543cc04b..4e07b5ca847c 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -215,31 +215,17 @@ static struct block_device_operations cciss_fops = {
/*
* Enqueuing and dequeuing functions for cmdlists.
*/
-static inline void addQ(CommandList_struct **Qptr, CommandList_struct *c)
+static inline void addQ(struct hlist_head *list, CommandList_struct *c)
{
- if (*Qptr == NULL) {
- *Qptr = c;
- c->next = c->prev = c;
- } else {
- c->prev = (*Qptr)->prev;
- c->next = (*Qptr);
- (*Qptr)->prev->next = c;
- (*Qptr)->prev = c;
- }
+ hlist_add_head(&c->list, list);
}
-static inline CommandList_struct *removeQ(CommandList_struct **Qptr,
- CommandList_struct *c)
+static inline void removeQ(CommandList_struct *c)
{
- if (c && c->next != c) {
- if (*Qptr == c)
- *Qptr = c->next;
- c->prev->next = c->next;
- c->next->prev = c->prev;
- } else {
- *Qptr = NULL;
- }
- return c;
+ if (WARN_ON(hlist_unhashed(&c->list)))
+ return;
+
+ hlist_del_init(&c->list);
}
#include "cciss_scsi.c" /* For SCSI tape support */
@@ -506,6 +492,7 @@ static CommandList_struct *cmd_alloc(ctlr_info_t *h, int get_from_pool)
c->cmdindex = i;
}
+ INIT_HLIST_NODE(&c->list);
c->busaddr = (__u32) cmd_dma_handle;
temp64.val = (__u64) err_dma_handle;
c->ErrDesc.Addr.lower = temp64.val32.lower;
@@ -2548,7 +2535,8 @@ static void start_io(ctlr_info_t *h)
{
CommandList_struct *c;
- while ((c = h->reqQ) != NULL) {
+ while (!hlist_empty(&h->reqQ)) {
+ c = hlist_entry(h->reqQ.first, CommandList_struct, list);
/* can't do anything if fifo is full */
if ((h->access.fifo_full(h))) {
printk(KERN_WARNING "cciss: fifo full\n");
@@ -2556,14 +2544,14 @@ static void start_io(ctlr_info_t *h)
}
/* Get the first entry from the Request Q */
- removeQ(&(h->reqQ), c);
+ removeQ(c);
h->Qdepth--;
/* Tell the controller execute command */
h->access.submit_command(h, c);
/* Put job onto the completed Q */
- addQ(&(h->cmpQ), c);
+ addQ(&h->cmpQ, c);
}
}
@@ -2576,7 +2564,7 @@ static inline void resend_cciss_cmd(ctlr_info_t *h, CommandList_struct *c)
memset(c->err_info, 0, sizeof(ErrorInfo_struct));
/* add it to software queue and then send it to the controller */
- addQ(&(h->reqQ), c);
+ addQ(&h->reqQ, c);
h->Qdepth++;
if (h->Qdepth > h->maxQsinceinit)
h->maxQsinceinit = h->Qdepth;
@@ -2897,7 +2885,7 @@ static void do_cciss_request(struct request_queue *q)
spin_lock_irq(q->queue_lock);
- addQ(&(h->reqQ), c);
+ addQ(&h->reqQ, c);
h->Qdepth++;
if (h->Qdepth > h->maxQsinceinit)
h->maxQsinceinit = h->Qdepth;
@@ -2985,16 +2973,12 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
a = c->busaddr;
} else {
+ struct hlist_node *tmp;
+
a &= ~3;
- if ((c = h->cmpQ) == NULL) {
- printk(KERN_WARNING
- "cciss: Completion of %08x ignored\n",
- a1);
- continue;
- }
- while (c->busaddr != a) {
- c = c->next;
- if (c == h->cmpQ)
+ c = NULL;
+ hlist_for_each_entry(c, tmp, &h->cmpQ, list) {
+ if (c->busaddr == a)
break;
}
}
@@ -3002,8 +2986,8 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
* If we've found the command, take it off the
* completion Q and free it
*/
- if (c->busaddr == a) {
- removeQ(&h->cmpQ, c);
+ if (c && c->busaddr == a) {
+ removeQ(c);
if (c->cmd_type == CMD_RWREQ) {
complete_command(h, c, 0);
} else if (c->cmd_type == CMD_IOCTL_PEND) {
@@ -3423,6 +3407,8 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
return -1;
hba[i]->busy_initializing = 1;
+ INIT_HLIST_HEAD(&hba[i]->cmpQ);
+ INIT_HLIST_HEAD(&hba[i]->reqQ);
if (cciss_pci_init(hba[i], pdev) != 0)
goto clean1;
@@ -3730,15 +3716,17 @@ static void fail_all_cmds(unsigned long ctlr)
pci_disable_device(h->pdev); /* Make sure it is really dead. */
/* move everything off the request queue onto the completed queue */
- while ((c = h->reqQ) != NULL) {
- removeQ(&(h->reqQ), c);
+ while (!hlist_empty(&h->reqQ)) {
+ c = hlist_entry(h->reqQ.first, CommandList_struct, list);
+ removeQ(c);
h->Qdepth--;
- addQ(&(h->cmpQ), c);
+ addQ(&h->cmpQ, c);
}
/* Now, fail everything on the completed queue with a HW error */
- while ((c = h->cmpQ) != NULL) {
- removeQ(&h->cmpQ, c);
+ while (!hlist_empty(&h->cmpQ)) {
+ c = hlist_entry(h->cmpQ.first, CommandList_struct, list);
+ removeQ(c);
c->err_info->CommandStatus = CMD_HARDWARE_ERR;
if (c->cmd_type == CMD_RWREQ) {
complete_command(h, c, 0);
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 24a7efa993ab..15e2b84734e3 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -89,8 +89,8 @@ struct ctlr_info
struct access_method access;
/* queue and queue Info */
- CommandList_struct *reqQ;
- CommandList_struct *cmpQ;
+ struct hlist_head reqQ;
+ struct hlist_head cmpQ;
unsigned int Qdepth;
unsigned int maxQsinceinit;
unsigned int maxSG;
diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h
index 43bf5593b59b..24e22dea1a99 100644
--- a/drivers/block/cciss_cmd.h
+++ b/drivers/block/cciss_cmd.h
@@ -265,8 +265,7 @@ typedef struct _CommandList_struct {
int ctlr;
int cmd_type;
long cmdindex;
- struct _CommandList_struct *prev;
- struct _CommandList_struct *next;
+ struct hlist_node list;
struct request * rq;
struct completion *waiting;
int retry_count;