[patch 02/11] zfcp: Move FSF request tracking code to new file

Christof Schmitt
2010-02-17T10:20:23Z

[-- Attachment #1: 701-zfcp-fsf-tracking.diff --]
[-- Type: text/plain, Size: 16404 bytes --]

From: Christof Schmitt <christof.schmitt@de.ibm.com>

Move the code for tracking FSF requests to new file to have this code
in one place. The functions for adding and removing requests on the
I/O path are already inline. The alloc and free functions are only
called once, so it does not hurt to inline them and add them to the
same file.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
---

drivers/s390/scsi/zfcp_aux.c | 36 -------
drivers/s390/scsi/zfcp_ccw.c | 3
drivers/s390/scsi/zfcp_def.h | 34 -------
drivers/s390/scsi/zfcp_erp.c | 7 -
drivers/s390/scsi/zfcp_ext.h | 1
drivers/s390/scsi/zfcp_fsf.c | 32 +-----
drivers/s390/scsi/zfcp_reqlist.h | 183 +++++++++++++++++++++++++++++++++++++++
drivers/s390/scsi/zfcp_scsi.c | 5 -
8 files changed, 203 insertions(+), 98 deletions(-)

diff -urpN linux-2.6/drivers/s390/scsi/zfcp_aux.c linux-2.6-patched/drivers/s390/scsi/zfcp_aux.c
--- linux-2.6/drivers/s390/scsi/zfcp_aux.c 2010-02-16 09:43:05.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_aux.c 2010-02-16 09:43:29.000000000 +0100
@@ -32,6 +32,7 @@
#include <linux/seq_file.h>
#include "zfcp_ext.h"
#include "zfcp_fc.h"
+#include "zfcp_reqlist.h"

#define ZFCP_BUS_ID_SIZE 20

@@ -49,36 +50,6 @@ static struct kmem_cache *zfcp_cache_hw_
return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
}

-static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
-{
- int idx;
-
- adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
- GFP_KERNEL);
- if (!adapter->req_list)
- return -ENOMEM;
-
- for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
- INIT_LIST_HEAD(&adapter->req_list[idx]);
- return 0;
-}
-
-/**
- * zfcp_reqlist_isempty - is the request list empty
- * @adapter: pointer to struct zfcp_adapter
- *
- * Returns: true if list is empty, false otherwise
- */
-int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
-{
- unsigned int idx;
-
- for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
- if (!list_empty(&adapter->req_list[idx]))
- return 0;
- return 1;
-}
-
static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
{
struct ccw_device *cdev;
@@ -539,7 +510,8 @@ struct zfcp_adapter *zfcp_adapter_enqueu
if (zfcp_allocate_low_mem_buffers(adapter))
goto failed;

- if (zfcp_reqlist_alloc(adapter))
+ adapter->req_list = zfcp_reqlist_alloc();
+ if (!adapter->req_list)
goto failed;

if (zfcp_dbf_adapter_register(adapter))
@@ -560,8 +532,6 @@ struct zfcp_adapter *zfcp_adapter_enqueu
INIT_LIST_HEAD(&adapter->erp_ready_head);
INIT_LIST_HEAD(&adapter->erp_running_head);

- spin_lock_init(&adapter->req_list_lock);
-
rwlock_init(&adapter->erp_lock);
rwlock_init(&adapter->abort_lock);

diff -urpN linux-2.6/drivers/s390/scsi/zfcp_ccw.c linux-2.6-patched/drivers/s390/scsi/zfcp_ccw.c
--- linux-2.6/drivers/s390/scsi/zfcp_ccw.c 2010-02-16 09:43:05.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_ccw.c 2010-02-16 09:43:29.000000000 +0100
@@ -10,6 +10,7 @@
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include "zfcp_ext.h"
+#include "zfcp_reqlist.h"

#define ZFCP_MODEL_PRIV 0x4

@@ -162,7 +163,7 @@ static int zfcp_ccw_set_online(struct cc
}

/* initialize request counter */
- BUG_ON(!zfcp_reqlist_isempty(adapter));
+ BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
adapter->req_no = 0;

zfcp_erp_modify_adapter_status(adapter, "ccsonl1", NULL,
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_def.h linux-2.6-patched/drivers/s390/scsi/zfcp_def.h
--- linux-2.6/drivers/s390/scsi/zfcp_def.h 2010-02-16 09:43:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_def.h 2010-02-16 09:43:29.000000000 +0100
@@ -39,9 +39,7 @@
#include <asm/sysinfo.h>
#include "zfcp_fsf.h"

-/********************* GENERAL DEFINES *********************************/
-
-#define REQUEST_LIST_SIZE 128
+struct zfcp_reqlist;

/********************* SCSI SPECIFIC DEFINES *********************************/
#define ZFCP_SCSI_ER_TIMEOUT (10*HZ)
@@ -206,8 +204,7 @@ struct zfcp_adapter {
struct list_head port_list; /* remote port list */
rwlock_t port_list_lock; /* port list lock */
unsigned long req_no; /* unique FSF req number */
- struct list_head *req_list; /* list of pending reqs */
- spinlock_t req_list_lock; /* request list lock */
+ struct zfcp_reqlist *req_list;
u32 fsf_req_seq_no; /* FSF cmnd seq number */
rwlock_t abort_lock; /* Protects against SCSI
stack abort/command
@@ -351,31 +348,4 @@ struct zfcp_data {
#define ZFCP_SET 0x00000100
#define ZFCP_CLEAR 0x00000200

-/*
- * Helper functions for request ID management.
- */
-static inline int zfcp_reqlist_hash(unsigned long req_id)
-{
- return req_id % REQUEST_LIST_SIZE;
-}
-
-static inline void zfcp_reqlist_remove(struct zfcp_adapter *adapter,
- struct zfcp_fsf_req *fsf_req)
-{
- list_del(&fsf_req->list);
-}
-
-static inline struct zfcp_fsf_req *
-zfcp_reqlist_find(struct zfcp_adapter *adapter, unsigned long req_id)
-{
- struct zfcp_fsf_req *request;
- unsigned int idx;
-
- idx = zfcp_reqlist_hash(req_id);
- list_for_each_entry(request, &adapter->req_list[idx], list)
- if (request->req_id == req_id)
- return request;
- return NULL;
-}
-
#endif /* ZFCP_DEF_H */
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_erp.c linux-2.6-patched/drivers/s390/scsi/zfcp_erp.c
--- linux-2.6/drivers/s390/scsi/zfcp_erp.c 2010-02-16 09:43:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_erp.c 2010-02-16 09:43:29.000000000 +0100
@@ -11,6 +11,7 @@

#include <linux/kthread.h>
#include "zfcp_ext.h"
+#include "zfcp_reqlist.h"

#define ZFCP_MAX_ERPS 3

@@ -483,8 +484,8 @@ static void zfcp_erp_strategy_check_fsfr
if (!act->fsf_req_id)
return;

- spin_lock(&adapter->req_list_lock);
- req = zfcp_reqlist_find(adapter, act->fsf_req_id);
+ spin_lock(&adapter->req_list->lock);
+ req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
if (req && req->erp_action == act) {
if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
ZFCP_STATUS_ERP_TIMEDOUT)) {
@@ -498,7 +499,7 @@ static void zfcp_erp_strategy_check_fsfr
act->fsf_req_id = 0;
} else
act->fsf_req_id = 0;
- spin_unlock(&adapter->req_list_lock);
+ spin_unlock(&adapter->req_list->lock);
}

/**
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_ext.h linux-2.6-patched/drivers/s390/scsi/zfcp_ext.h
--- linux-2.6/drivers/s390/scsi/zfcp_ext.h 2010-02-16 09:43:05.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_ext.h 2010-02-16 09:43:29.000000000 +0100
@@ -21,7 +21,6 @@ extern struct zfcp_adapter *zfcp_adapter
extern struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *, u64, u32,
u32);
extern struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *, u64);
-extern int zfcp_reqlist_isempty(struct zfcp_adapter *);
extern void zfcp_sg_free_table(struct scatterlist *, int);
extern int zfcp_sg_setup_table(struct scatterlist *, int);
extern void zfcp_device_unregister(struct device *,
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_fsf.c linux-2.6-patched/drivers/s390/scsi/zfcp_fsf.c
--- linux-2.6/drivers/s390/scsi/zfcp_fsf.c 2010-02-16 09:43:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_fsf.c 2010-02-16 09:43:29.000000000 +0100
@@ -14,6 +14,7 @@
#include "zfcp_ext.h"
#include "zfcp_fc.h"
#include "zfcp_dbf.h"
+#include "zfcp_reqlist.h"

static void zfcp_fsf_request_timeout_handler(unsigned long data)
{
@@ -457,15 +458,10 @@ static void zfcp_fsf_req_complete(struct
void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
{
struct zfcp_fsf_req *req, *tmp;
- unsigned long flags;
LIST_HEAD(remove_queue);
- unsigned int i;

BUG_ON(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP);
- spin_lock_irqsave(&adapter->req_list_lock, flags);
- for (i = 0; i < REQUEST_LIST_SIZE; i++)
- list_splice_init(&adapter->req_list[i], &remove_queue);
- spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+ zfcp_reqlist_move(adapter->req_list, &remove_queue);

list_for_each_entry_safe(req, tmp, &remove_queue, list) {
list_del(&req->list);
@@ -770,27 +766,17 @@ static int zfcp_fsf_req_send(struct zfcp
{
struct zfcp_adapter *adapter = req->adapter;
struct zfcp_qdio *qdio = adapter->qdio;
- unsigned long flags;
- int idx;
- int with_qtcb = (req->qtcb != NULL);
+ int with_qtcb = (req->qtcb != NULL);
int req_id = req->req_id;

- /* put allocated FSF request into hash table */
- spin_lock_irqsave(&adapter->req_list_lock, flags);
- idx = zfcp_reqlist_hash(req_id);
- list_add_tail(&req->list, &adapter->req_list[idx]);
- spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+ zfcp_reqlist_add(adapter->req_list, req);

req->queue_req.qdio_outb_usage = atomic_read(&qdio->req_q.count);
req->issued = get_clock();
if (zfcp_qdio_send(qdio, &req->queue_req)) {
del_timer(&req->timer);
- spin_lock_irqsave(&adapter->req_list_lock, flags);
/* lookup request again, list might have changed */
- req = zfcp_reqlist_find(adapter, req_id);
- if (req)
- zfcp_reqlist_remove(adapter, req);
- spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+ zfcp_reqlist_find_rm(adapter->req_list, req_id);
zfcp_erp_adapter_reopen(adapter, 0, "fsrs__1", req);
return -EIO;
}
@@ -2518,15 +2504,14 @@ void zfcp_fsf_reqid_check(struct zfcp_qd
struct qdio_buffer *sbal = qdio->resp_q.sbal[sbal_idx];
struct qdio_buffer_element *sbale;
struct zfcp_fsf_req *fsf_req;
- unsigned long flags, req_id;
+ unsigned long req_id;
int idx;

for (idx = 0; idx < QDIO_MAX_ELEMENTS_PER_BUFFER; idx++) {

sbale = &sbal->element[idx];
req_id = (unsigned long) sbale->addr;
- spin_lock_irqsave(&adapter->req_list_lock, flags);
- fsf_req = zfcp_reqlist_find(adapter, req_id);
+ fsf_req = zfcp_reqlist_find_rm(adapter->req_list, req_id);

if (!fsf_req)
/*
@@ -2536,9 +2521,6 @@ void zfcp_fsf_reqid_check(struct zfcp_qd
panic("error: unknown req_id (%lx) on adapter %s.\n",
req_id, dev_name(&adapter->ccw_device->dev));

- list_del(&fsf_req->list);
- spin_unlock_irqrestore(&adapter->req_list_lock, flags);
-
fsf_req->queue_req.sbal_response = sbal_idx;
fsf_req->queue_req.qdio_inb_usage =
atomic_read(&qdio->resp_q.count);
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_reqlist.h linux-2.6-patched/drivers/s390/scsi/zfcp_reqlist.h
--- linux-2.6/drivers/s390/scsi/zfcp_reqlist.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_reqlist.h 2010-02-16 09:43:29.000000000 +0100
@@ -0,0 +1,183 @@
+/*
+ * zfcp device driver
+ *
+ * Data structure and helper functions for tracking pending FSF
+ * requests.
+ *
+ * Copyright IBM Corporation 2009
+ */
+
+#ifndef ZFCP_REQLIST_H
+#define ZFCP_REQLIST_H
+
+/* number of hash buckets */
+#define ZFCP_REQ_LIST_BUCKETS 128
+
+/**
+ * struct zfcp_reqlist - Container for request list (reqlist)
+ * @lock: Spinlock for protecting the hash list
+ * @list: Array of hashbuckets, each is a list of requests in this bucket
+ */
+struct zfcp_reqlist {
+ spinlock_t lock;
+ struct list_head buckets[ZFCP_REQ_LIST_BUCKETS];
+};
+
+static inline int zfcp_reqlist_hash(unsigned long req_id)
+{
+ return req_id % ZFCP_REQ_LIST_BUCKETS;
+}
+
+/**
+ * zfcp_reqlist_alloc - Allocate and initialize reqlist
+ *
+ * Returns pointer to allocated reqlist on success, or NULL on
+ * allocation failure.
+ */
+static inline struct zfcp_reqlist *zfcp_reqlist_alloc(void)
+{
+ unsigned int i;
+ struct zfcp_reqlist *rl;
+
+ rl = kzalloc(sizeof(struct zfcp_reqlist), GFP_KERNEL);
+ if (!rl)
+ return NULL;
+
+ spin_lock_init(&rl->lock);
+
+ for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++)
+ INIT_LIST_HEAD(&rl->buckets[i]);
+
+ return rl;
+}
+
+/**
+ * zfcp_reqlist_isempty - Check whether the request list empty
+ * @rl: pointer to reqlist
+ *
+ * Returns: 1 if list is empty, 0 if not
+ */
+static inline int zfcp_reqlist_isempty(struct zfcp_reqlist *rl)
+{
+ unsigned int i;
+
+ for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++)
+ if (!list_empty(&rl->buckets[i]))
+ return 0;
+ return 1;
+}
+
+/**
+ * zfcp_reqlist_free - Free allocated memory for reqlist
+ * @rl: The reqlist where to free memory
+ */
+static inline void zfcp_reqlist_free(struct zfcp_reqlist *rl)
+{
+ /* sanity check */
+ BUG_ON(!zfcp_reqlist_isempty(rl));
+
+ kfree(rl);
+}
+
+static inline struct zfcp_fsf_req *
+_zfcp_reqlist_find(struct zfcp_reqlist *rl, unsigned long req_id)
+{
+ struct zfcp_fsf_req *req;
+ unsigned int i;
+
+ i = zfcp_reqlist_hash(req_id);
+ list_for_each_entry(req, &rl->buckets[i], list)
+ if (req->req_id == req_id)
+ return req;
+ return NULL;
+}
+
+/**
+ * zfcp_reqlist_find - Lookup FSF request by its request id
+ * @rl: The reqlist where to lookup the FSF request
+ * @req_id: The request id to look for
+ *
+ * Returns a pointer to the FSF request with the specified request id
+ * or NULL if there is no known FSF request with this id.
+ */
+static inline struct zfcp_fsf_req *
+zfcp_reqlist_find(struct zfcp_reqlist *rl, unsigned long req_id)
+{
+ unsigned long flags;
+ struct zfcp_fsf_req *req;
+
+ spin_lock_irqsave(&rl->lock, flags);
+ req = _zfcp_reqlist_find(rl, req_id);
+ spin_unlock_irqrestore(&rl->lock, flags);
+
+ return req;
+}
+
+/**
+ * zfcp_reqlist_find_rm - Lookup request by id and remove it from reqlist
+ * @rl: reqlist where to search and remove entry
+ * @req_id: The request id of the request to look for
+ *
+ * This functions tries to find the FSF request with the specified
+ * id and then removes it from the reqlist. The reqlist lock is held
+ * during both steps of the operation.
+ *
+ * Returns: Pointer to the FSF request if the request has been found,
+ * NULL if it has not been found.
+ */
+static inline struct zfcp_fsf_req *
+zfcp_reqlist_find_rm(struct zfcp_reqlist *rl, unsigned long req_id)
+{
+ unsigned long flags;
+ struct zfcp_fsf_req *req;
+
+ spin_lock_irqsave(&rl->lock, flags);
+ req = _zfcp_reqlist_find(rl, req_id);
+ if (req)
+ list_del(&req->list);
+ spin_unlock_irqrestore(&rl->lock, flags);
+
+ return req;
+}
+
+/**
+ * zfcp_reqlist_add - Add entry to reqlist
+ * @rl: reqlist where to add the entry
+ * @req: The entry to add
+ *
+ * The request id always increases. As an optimization new requests
+ * are added here with list_add_tail at the end of the bucket lists
+ * while old requests are looked up starting at the beginning of the
+ * lists.
+ */
+static inline void zfcp_reqlist_add(struct zfcp_reqlist *rl,
+ struct zfcp_fsf_req *req)
+{
+ unsigned int i;
+ unsigned long flags;
+
+ i = zfcp_reqlist_hash(req->req_id);
+
+ spin_lock_irqsave(&rl->lock, flags);
+ list_add_tail(&req->list, &rl->buckets[i]);
+ spin_unlock_irqrestore(&rl->lock, flags);
+}
+
+/**
+ * zfcp_reqlist_move - Move all entries from reqlist to simple list
+ * @rl: The zfcp_reqlist where to remove all entries
+ * @list: The list where to move all entries
+ */
+static inline void zfcp_reqlist_move(struct zfcp_reqlist *rl,
+ struct list_head *list)
+{
+ unsigned int i;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rl->lock, flags);
+ for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++)
+ list_splice_init(&rl->buckets[i], list);
+ spin_unlock_irqrestore(&rl->lock, flags);
+}
+
+#endif /* ZFCP_REQLIST_H */
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_scsi.c linux-2.6-patched/drivers/s390/scsi/zfcp_scsi.c
--- linux-2.6/drivers/s390/scsi/zfcp_scsi.c 2010-02-16 09:43:05.000000000 +0100
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_scsi.c 2010-02-16 09:43:29.000000000 +0100
@@ -15,6 +15,7 @@
#include "zfcp_ext.h"
#include "zfcp_dbf.h"
#include "zfcp_fc.h"
+#include "zfcp_reqlist.h"

static unsigned int default_depth = 32;
module_param_named(queue_depth, default_depth, uint, 0600);
@@ -189,9 +190,7 @@ static int zfcp_scsi_eh_abort_handler(st
/* avoid race condition between late normal completion and abort */
write_lock_irqsave(&adapter->abort_lock, flags);

- spin_lock(&adapter->req_list_lock);
- old_req = zfcp_reqlist_find(adapter, old_reqid);
- spin_unlock(&adapter->req_list_lock);
+ old_req = zfcp_reqlist_find(adapter->req_list, old_reqid);
if (!old_req) {
write_unlock_irqrestore(&adapter->abort_lock, flags);
zfcp_dbf_scsi_abort("lte1", adapter->dbf, scpnt, NULL,