[dm-devel] 1st of 2 patches for dm_emc.c and dm-multipath hardware handler interface
Edward Goggin
egoggin at emc.com
Thu Aug 31 14:32:09 UTC 2006
This is the 2nd take on a set of patches submitted about
3 weeks ago intended to (1) avoid unnecessary dm-multipath
path group switch-over events for EMC CLARiiON and
(2) improve the event logging of the dm-multipath hardware
handler interface.
This patch set differs from previous patch set by:
- There are now two patches -- the first for content
specific to the EMC CLARiiON dm-multipath hardware
handler dm_emc.c. -- the second to dm, dm-multipath,
and dm-multipath hardware handler framework code to
support an improved event logging capability for
hardware handlers.
- The dm_emc.c hw handler now gets requests from
blk_get_request instead of using pre-allocated requests.
As a result, the rq_init macro of ll_rw_blk.c is no
longer converted to a function and exported.
- The dm_emc.c hw handler now issues its ios asynchronously
via blk_execute_rq_nowait and has a single threaded worker
queue to allocate and queue the io requests.
- The 2nd patch exports dm_put instead of a new function
dm_table_put_md.
- The 2nd patch modifies the dm-multipath hardware handler
interface by adding a 4th parameter, a ptr to the mapped
device, to the create callout instead of adding a new init
callout. dm_mpath.c and dm_emc.c are changed to pass and
use this additional parameter respectively.
- Coding and patch conventions followed.
use "diff -up"
no lines of code > 80 chars
avoids mixed case variable names
start else clause on same line as "}"
EXPORT_SYMBOL_GPL reference immediately after function
This is the first patch (dm_emc.c only) in a set of 2 patches.
Signed-off-by: Ed Goggin <egoggin at emc.com>
--- linux-2.6.18-rc4/drivers/md/dm-emc.c.orig 2006-08-28
22:37:34.000000000 -0500
+++ linux-2.6.18-rc4/drivers/md/dm-emc.c 2006-08-28
22:20:17.000000000 -0500
@@ -7,227 +7,448 @@
* Multipath support for EMC CLARiiON AX/CX-series hardware.
*/
+/* Code borrowed from dm-lsi-rdac by Mike Christie */
+
#include "dm.h"
#include "dm-hw-handler.h"
#include <scsi/scsi.h>
+#include <scsi/scsi_eh.h>
#include <scsi/scsi_cmnd.h>
-#define DM_MSG_PREFIX "multipath emc"
+#define DM_MSG_PREFIX "multipath emc"
+#define TRESPASS_PAGE 0x22
+#define BUFFER_SIZE 0x80
+#define EMC_HANDLER_TIMEOUT (60 * HZ)
+#define UNBOUND_LU -1
+/*
+ * Four variations of the CLARiiON trespass MODE_SENSE page.
+ */
+unsigned char long_trespass_and_hr_pg[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x09, /* Page length - 2 */
+ 0x01, /* Trespass code + Honor reservation bit
*/
+ 0xff, 0xff, /* Trespass target */
+ 0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
+};
+unsigned char long_trespass_pg[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x09, /* Page length - 2 */
+ 0x81, /* Trespass code + Honor reservation bit
*/
+ 0xff, 0xff, /* Trespass target */
+ 0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
+};
+unsigned char short_trespass_and_hr_pg[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x02, /* Page length - 2 */
+ 0x01, /* Trespass code + Honor reservation bit
*/
+ 0xff, /* Trespass target */
+};
+unsigned char short_trespass_pg[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x02, /* Page length - 2 */
+ 0x81, /* Trespass code + Honor reservation bit
*/
+ 0xff, /* Trespass target */
+};
+
+/*
+ * EMC hardware handler context structure containing CLARiiON LU
specific
+ * information for a particular dm multipath mapped device.
+ */
struct emc_handler {
spinlock_t lock;
-
- /* Whether we should send the short trespass command (FC-series)
- * or the long version (default for AX/CX CLARiiON arrays). */
+ struct hw_handler *hwh;
+ struct path *path;
+ struct work_struct wkq;
+ /* Use short trespass command (FC-series) or the long version
+ * (default for AX/CX CLARiiON arrays). */
unsigned short_trespass;
- /* Whether or not to honor SCSI reservations when initiating a
- * switch-over. Default: Don't. */
+ /* Whether or not (default) to honor SCSI reservations when
+ * initiating a switch-over. */
unsigned hr;
-
+ /* I/O buffer for both MODE_SELECT and INQUIRY commands. */
+ char buffer[BUFFER_SIZE];
+ /* SCSI sense buffer for commands -- assumes serial issuance
+ * and completion sequence of all commands for same multipath.
*/
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+ /* which SP (A=0,B=1,UNBOUND=-1) is dflt SP for path's mapped
dev */
+ int default_sp;
+ /* which SP (A=0,B=1,UNBOUND=-1) is active for path's mapped dev
*/
+ int current_sp;
+ /*
+ * flag when set (reset) differentiates get_sp_info after
(before)
+ * pg_init
+ */
+ int pg_init_sent;
};
-#define TRESPASS_PAGE 0x22
-#define EMC_FAILOVER_TIMEOUT (60 * HZ)
+static int send_cmd(struct emc_handler *h, struct path *path, int cmd,
+ rq_end_io_fn *endio);
+static rq_end_io_fn sp_info_endio, pg_init_endio;
+static int parse_sp_info_reply(struct request *req, struct emc_handler
*h,
+ struct path *path, int *default_sp,
+ int *current_sp, int *new_current_sp);
+static int parse_pg_init_reply(struct request *req, struct emc_handler
*h,
+ struct path *path);
-/* Code borrowed from dm-lsi-rdac by Mike Christie */
+struct workqueue_struct *kemchd;
-static inline void free_bio(struct bio *bio)
-{
- __free_page(bio->bi_io_vec[0].bv_page);
- bio_put(bio);
+/*
+ * Parse EVPD 0xC0 INQUIRY cmd reply.
+ */
+static int parse_sp_info_reply(struct request *req, struct emc_handler
*h,
+ struct path *path, int *default_sp,
+ int *current_sp, int *new_current_sp)
+{
+ int err = 0;
+
+ if (req->errors == 0) {
+ /* check for in-progress ucode upgrade (NDU) */
+ if (h->buffer[48] != 0) {
+ DMWARN("Detected in-progress ucode upgrade NDU "
+ "operation while finding current active "
+ "SP using path %s.", path->dev->name);
+ err = MP_BYPASS_PG;
+ } else {
+ *default_sp = h->buffer[5];
+
+ if (h->buffer[4] == 2)
+ /* SP for path (in h->buffer[8]) is
current */
+ *current_sp = h->buffer[8];
+ else {
+ if (h->buffer[4] == 1)
+ /* SP for this path is NOT
current */
+ if (h->buffer[8] == 0)
+ *current_sp = 1;
+ else
+ *current_sp = 0;
+ else
+ /* unbound LU or LUNZ */
+ *current_sp = UNBOUND_LU;
+ }
+ *new_current_sp = h->buffer[8];
+ }
+ } else {
+ struct scsi_sense_hdr sshdr;
+
+ err = MP_FAIL_PATH;
+
+ if (req->sense_len && scsi_normalize_sense(req->sense,
+
req->sense_len,
+ &sshdr))
+ DMERR("Found valid sense data 0x%2x, 0x%2x,
0x%2x "
+ "while finding current active SP using
path %s.",
+ sshdr.sense_key, sshdr.asc, sshdr.ascq,
+ path->dev->name);
+ else DMERR("Error 0x%x finding current active SP using "
+ "path %s.", req->errors, path->dev->name);
+ }
+
+ return (err);
}
-static int emc_endio(struct bio *bio, unsigned int bytes_done, int
error)
+/*
+ * Parse MODE_SELECT cmd reply.
+ */
+static int parse_pg_init_reply(struct request *req, struct emc_handler
*h,
+ struct path *path)
{
- struct path *path = bio->bi_private;
+ struct scsi_sense_hdr sshdr;
+ int err = 0;
- if (bio->bi_size)
- return 1;
+ if (req->sense_len && scsi_normalize_sense(req->sense,
+ req->sense_len,
&sshdr)) {
- /* We also need to look at the sense keys here whether or not to
- * switch to the next PG etc.
- *
- * For now simple logic: either it works or it doesn't.
- */
- if (error)
- dm_pg_init_complete(path, MP_FAIL_PATH);
- else
- dm_pg_init_complete(path, 0);
+ DMERR("Found valid sense data 0x%2x, 0x%2x, 0x%2x while
"
+ "sending CLARiiON trespass command using path
%s.",
+ sshdr.sense_key, sshdr.asc, sshdr.ascq,
path->dev->name);
+
+ if ((sshdr.sense_key = 0x05) &&
+ (sshdr.asc = 0x04) &&
+ (sshdr.ascq = 0x00)) {
+ /*
+ * Array based copy in progress -- do not send
+ * pg_init or copy will be aborted mid-stream.
+ */
+ DMWARN("Array Based Copy in progress while "
+ "sending CLARiiON trespass command "
+ "using path %s.", path->dev->name);
+ err = MP_BYPASS_PG;
+ } else if ((sshdr.sense_key = 0x02) &&
+ (sshdr.asc = 0x04) &&
+ (sshdr.ascq = 0x03)) {
+ /*
+ * LUN Not Ready - Manual Intervention Required
+ * indicates in-progress ucode upgrade (NDU).
+ */
+ DMWARN("Detected in-progress ucode upgrade NDU "
+ "operation while sending CLARiiON
trespass "
+ " command using path %s.",
path->dev->name);
+ err = MP_BYPASS_PG;
+ } else
+ err = MP_FAIL_PATH;
+ } else if (req->errors) {
+ DMERR("Error 0x%x while sending CLARiiON trespass
command "
+ "using path %s.", req->errors, path->dev->name);
+ err = MP_FAIL_PATH;
+ }
- /* request is freed in block layer */
- free_bio(bio);
+ /* release ref on block request */
+ __blk_put_request(req->q, req);
- return 0;
+ return (err);
}
-static struct bio *get_failover_bio(struct path *path, unsigned
data_size)
+/*
+ * Completion handler for EVPD page 0xC0 INQUIRY cmd.
+ */
+static void sp_info_endio(struct request *req, int uptodate)
{
- struct bio *bio;
- struct page *page;
+ struct path *path = req->end_io_data;
+ struct emc_handler *h = (struct emc_handler *)path->hwhcontext;
+ int default_sp, current_sp, new_current_sp;
+ unsigned long flags;
+ int err_flags;
- bio = bio_alloc(GFP_ATOMIC, 1);
- if (!bio) {
- DMERR("get_failover_bio: bio_alloc() failed.");
- return NULL;
- }
+ if ((err_flags = parse_sp_info_reply(req, h, path, &default_sp,
+ ¤t_sp,
&new_current_sp))) {
+ dm_pg_init_complete(path, err_flags);
- bio->bi_rw |= (1 << BIO_RW);
- bio->bi_bdev = path->dev->bdev;
- bio->bi_sector = 0;
- bio->bi_private = path;
- bio->bi_end_io = emc_endio;
-
- page = alloc_page(GFP_ATOMIC);
- if (!page) {
- DMERR("get_failover_bio: alloc_page() failed.");
- bio_put(bio);
- return NULL;
+ /* release ref on block request */
+ __blk_put_request(req->q, req);
+
+ return;
}
- if (bio_add_page(bio, page, data_size, 0) != data_size) {
- DMERR("get_failover_bio: alloc_page() failed.");
- __free_page(page);
- bio_put(bio);
- return NULL;
+ /* release ref on block request */
+ __blk_put_request(req->q, req);
+
+ spin_lock_irqsave(&h->lock, flags);
+ if (h->pg_init_sent) {
+ h->default_sp = default_sp;
+ h->current_sp = current_sp;
+ h->pg_init_sent = 0;
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ /* done now */
+ dm_pg_init_complete(path, 0);
+ } else {
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ /*
+ * Do not issue the actual pg_init request if either (1)
+ * we do not know the identity of the current SP or (2)
+ * the prospective new SP is already current.
+ */
+ if ((current_sp != UNBOUND_LU) &&
+ (new_current_sp == current_sp)) {
+
+ spin_lock_irqsave(&h->lock, flags);
+ if (h->default_sp == UNBOUND_LU) {
+ h->default_sp = default_sp;
+ h->current_sp = current_sp;
+ }
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ /* yet, its as good as doing it */
+ dm_pg_init_complete(path, 0);
+ DMINFO("Ignoring path group switch-over command
for "
+ "CLARiiON SP%s since mapped device is "
+ "already initialized for path %s.",
+ current_sp ? "B" : "A", path->dev->name);
+ } else {
+ /* send path initialization request */
+ DMINFO("Issuing CLARiiON trespass command to "
+ "activate SP%s using path %s.",
+ new_current_sp ? "B" : "A",
path->dev->name);
+
+ h->path = path; /* kemchd will use this path */
+ queue_work(kemchd, &h->wkq);
+ }
}
- return bio;
+ return;
+}
+
+/*
+ * Completion handler for MODE_SELECT cmd.
+ */
+static void pg_init_endio(struct request *req, int uptodate)
+{
+ struct path *path = req->end_io_data;
+ struct emc_handler *h = (struct emc_handler *)path->hwhcontext;
+ int err_flags;
+
+ if ((err_flags = parse_pg_init_reply(req, h, path)))
+ dm_pg_init_complete(path, err_flags);
+
+ /* release ref on block request */
+ __blk_put_request(req->q, req);
+
+ /* send sp_info request */
+ h->pg_init_sent = 1;
+ queue_work(kemchd, &h->wkq);
+
+ return;
}
-static struct request *get_failover_req(struct emc_handler *h,
- struct bio *bio, struct path
*path)
+/*
+ * Get block request for REQ_BLOCK_PC command issued to path.
Currently
+ * limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0)
commands.
+ *
+ * Uses data and sense buffers in hardware handler context structure
and
+ * assumes serial servicing of commands, both issuance and completion.
+ */
+static struct request *get_req(struct path *path, int opcode)
{
+ struct emc_handler *h = (struct emc_handler *)path->hwhcontext;
+ struct request_queue *q = bdev_get_queue(path->dev->bdev);
struct request *rq;
- struct block_device *bdev = bio->bi_bdev;
- struct request_queue *q = bdev_get_queue(bdev);
+ void *buffer;
+ int len = 0;
- /* FIXME: Figure out why it fails with GFP_ATOMIC. */
- rq = blk_get_request(q, WRITE, __GFP_WAIT);
+ rq = blk_get_request(q, (opcode == MODE_SELECT) ? WRITE : READ,
+ __GFP_WAIT);
if (!rq) {
- DMERR("get_failover_req: blk_get_request failed");
+ DMERR("dm-emc: get_req: blk_get_request failed");
return NULL;
}
- rq->bio = rq->biotail = bio;
- blk_rq_bio_prep(q, rq, bio);
-
- rq->rq_disk = bdev->bd_contains->bd_disk;
+ memset(&rq->cmd, 0, BLK_MAX_CDB);
+ rq->cmd[0] = opcode;
+ rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
- /* bio backed don't set data */
- rq->buffer = rq->data = NULL;
- /* rq data_len used for pc cmd's request_bufflen */
- rq->data_len = bio->bi_size;
+ switch (opcode) {
+ case MODE_SELECT:
+ rq->flags |= REQ_RW;
+ rq->cmd[1] = 0x10;
+ len = h->short_trespass ?
sizeof(short_trespass_and_hr_pg) :
+ sizeof(long_trespass_and_hr_pg);
+ buffer = h->short_trespass ?
+ h->hr ? short_trespass_and_hr_pg
+ : short_trespass_pg
+ :
+ h->hr ? long_trespass_and_hr_pg
+ : long_trespass_pg;
+ /*
+ * Can't DMA from kernel BSS -- must copy selected
trespass
+ * command mode page contents to context buffer which is
+ * allocated by kmalloc.
+ */
+ BUG_ON((len > BUFFER_SIZE));
+ memcpy(h->buffer, buffer, len);
+ break;
+ case INQUIRY:
+ rq->cmd[1] = 0x1;
+ rq->cmd[2] = 0xC0;
+ len = BUFFER_SIZE;
+ memset(h->buffer, 0, BUFFER_SIZE);
+ break;
+ default:
+ BUG_ON(1);
+ break;
+ }
+ rq->cmd[4] = len;
+
+ rq->buffer = rq->data = h->buffer;
+ rq->data_len = len;
+ rq->bio = rq->biotail = NULL;
rq->sense = h->sense;
memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
rq->sense_len = 0;
- memset(&rq->cmd, 0, BLK_MAX_CDB);
-
- rq->timeout = EMC_FAILOVER_TIMEOUT;
- rq->flags |= (REQ_BLOCK_PC | REQ_FAILFAST | REQ_NOMERGE);
+ rq->flags |= (REQ_BLOCK_PC | REQ_FAILFAST);
+ rq->timeout = EMC_HANDLER_TIMEOUT;
+ rq->retries = 0;
return rq;
}
-static struct request *emc_trespass_get(struct emc_handler *h,
- struct path *path)
+/*
+ * Send cmd and setup asynchronous i/o completion handler.
+ */
+static int send_cmd(struct emc_handler *h, struct path *path, int cmd,
+ rq_end_io_fn *endio)
{
- struct bio *bio;
+ struct request_queue *q = bdev_get_queue(path->dev->bdev);
struct request *rq;
- unsigned char *page22;
- unsigned char long_trespass_pg[] = {
- 0, 0, 0, 0,
- TRESPASS_PAGE, /* Page code */
- 0x09, /* Page length - 2 */
- h->hr ? 0x01 : 0x81, /* Trespass code + Honor
reservation bit */
- 0xff, 0xff, /* Trespass target */
- 0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
- };
- unsigned char short_trespass_pg[] = {
- 0, 0, 0, 0,
- TRESPASS_PAGE, /* Page code */
- 0x02, /* Page length - 2 */
- h->hr ? 0x01 : 0x81, /* Trespass code + Honor
reservation bit */
- 0xff, /* Trespass target */
- };
- unsigned data_size = h->short_trespass ?
sizeof(short_trespass_pg) :
- sizeof(long_trespass_pg);
-
- /* get bio backing */
- if (data_size > PAGE_SIZE)
- /* this should never happen */
- return NULL;
-
- bio = get_failover_bio(path, data_size);
- if (!bio) {
- DMERR("emc_trespass_get: no bio");
- return NULL;
- }
-
- page22 = (unsigned char *)bio_data(bio);
- memset(page22, 0, data_size);
- memcpy(page22, h->short_trespass ?
- short_trespass_pg : long_trespass_pg, data_size);
+ /* get and initialize block request */
+ rq = get_req(path, cmd);
+ if (!rq)
+ return MP_FAIL_PATH;
+
+ /* issue the cmd asynchronously (at head of q) */
+ rq->end_io_data = path;
+ blk_execute_rq_nowait(q, NULL, rq, 1, endio);
+ return 0;
+}
- /* get request for block layer packet command */
- rq = get_failover_req(h, bio, path);
- if (!rq) {
- DMERR("emc_trespass_get: no rq");
- free_bio(bio);
- return NULL;
+/*
+ * Work queue service routine used to issue i/o without already holding
+ * a request queue lock.
+ */
+static void service_wkq(void *data)
+{
+ struct emc_handler *h = (struct emc_handler *)data;
+ struct path *path = h->path;
+ int err_flags;
+
+ if (h->pg_init_sent) {
+ if ((err_flags = send_cmd(h, path, INQUIRY,
+ sp_info_endio))) {
+ h->pg_init_sent = 0;
+ dm_pg_init_complete(path, err_flags);
+ }
+ }
+ else {
+ /* send pg_init request */
+ if ((err_flags = send_cmd(h, path, MODE_SELECT,
+ pg_init_endio)))
+ dm_pg_init_complete(path, err_flags);
}
-
- /* Prepare the command. */
- rq->cmd[0] = MODE_SELECT;
- rq->cmd[1] = 0x10;
- rq->cmd[4] = data_size;
- rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
-
- return rq;
}
+/* initialize path group command */
static void emc_pg_init(struct hw_handler *hwh, unsigned bypassed,
struct path *path)
{
- struct request *rq;
- struct request_queue *q = bdev_get_queue(path->dev->bdev);
+ struct emc_handler *h = (struct emc_handler *)hwh->context;
+ int err_flags;
- /*
- * We can either blindly init the pg (then look at the sense),
- * or we can send some commands to get the state here (then
- * possibly send the fo cmnd), or we can also have the
- * initial state passed into us and then get an update here.
- */
- if (!q) {
- DMINFO("emc_pg_init: no queue");
- goto fail_path;
- }
+ path->hwhcontext = h; /* needed by endio handlers */
- /* FIXME: The request should be pre-allocated. */
- rq = emc_trespass_get(hwh->context, path);
- if (!rq) {
- DMERR("emc_pg_init: no rq");
- goto fail_path;
- }
-
- DMINFO("emc_pg_init: sending switch-over command");
- elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
+ if ((err_flags = send_cmd(h, path, INQUIRY, sp_info_endio)))
+ dm_pg_init_complete(path, err_flags);
return;
-
-fail_path:
- dm_pg_init_complete(path, MP_FAIL_PATH);
}
-static struct emc_handler *alloc_emc_handler(void)
+static struct emc_handler *alloc_emc_handler(unsigned int
short_trespass,
+ unsigned hr)
{
- struct emc_handler *h = kmalloc(sizeof(*h), GFP_KERNEL);
+ struct emc_handler *h = kzalloc(sizeof(*h), GFP_KERNEL);
if (h) {
- memset(h, 0, sizeof(*h));
spin_lock_init(&h->lock);
+
+ INIT_WORK(&h->wkq, service_wkq, h);
+
+ if ((h->short_trespass = short_trespass))
+ DMINFO("Short trespass command to be sent.");
+ else
+ DMINFO("Long trespass command to be sent
(default).");
+ if ((h->hr = hr))
+ DMINFO("Honor reservation bit will be set.");
+ else
+ DMINFO("Honor reservation bit is not set
(default).");
+
+ h->default_sp = UNBOUND_LU;
+ h->current_sp = UNBOUND_LU;
}
return h;
@@ -243,37 +464,30 @@ static int emc_create(struct hw_handler
hr = 0;
short_trespass = 0;
} else if (argc != 2) {
- DMWARN("incorrect number of arguments");
+ DMWARN("Incorrect number (0x%x) of arguments. "
+ "Should be 2.", argc);
return -EINVAL;
} else {
if ((sscanf(argv[0], "%u", &short_trespass) != 1)
|| (short_trespass > 1)) {
- DMWARN("invalid trespass mode selected");
+ DMWARN("Invalid trespass mode (0x%x) selected.",
+ short_trespass);
return -EINVAL;
}
if ((sscanf(argv[1], "%u", &hr) != 1)
|| (hr > 1)) {
- DMWARN("invalid honor reservation flag
selected");
+ DMWARN("Invalid honor reservation flag (0x%x).",
hr);
return -EINVAL;
}
}
- h = alloc_emc_handler();
+ h = alloc_emc_handler(short_trespass, hr);
if (!h)
return -ENOMEM;
hwh->context = h;
-
- if ((h->short_trespass = short_trespass))
- DMWARN("short trespass command will be send");
- else
- DMWARN("long trespass command will be send");
-
- if ((h->hr = hr))
- DMWARN("honor reservation bit will be set");
- else
- DMWARN("honor reservation bit will not be set
(default)");
+ h->hwh = hwh;
return 0;
}
@@ -324,6 +538,31 @@ static unsigned emc_error(struct hw_hand
return dm_scsi_err_handler(hwh, bio);
}
+static int emc_status(struct hw_handler *hwh, status_type_t type,
+ char *result, unsigned int maxlen)
+{
+ struct emc_handler *h = (struct emc_handler *)hwh->context;
+ unsigned long flags;
+
+ int sz = 0;
+
+ spin_lock_irqsave(&h->lock, flags);
+
+ if (type == STATUSTYPE_INFO)
+ DMEMIT("2 %d %d ", h->default_sp, h->current_sp);
+ else {
+ if (h->short_trespass || h->hr)
+ DMEMIT("3 %s %u %u ", hwh->type->name,
+ h->short_trespass, h->hr);
+ else
+ DMEMIT("1 %s ", hwh->type->name);
+ }
+
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ return sz;
+}
+
static struct hw_handler_type emc_hwh = {
.name = "emc",
.module = THIS_MODULE,
@@ -331,6 +570,7 @@ static struct hw_handler_type emc_hwh =
.destroy = emc_destroy,
.pg_init = emc_pg_init,
.error = emc_error,
+ .status = emc_status,
};
static int __init dm_emc_init(void)
@@ -338,19 +578,30 @@ static int __init dm_emc_init(void)
int r = dm_register_hw_handler(&emc_hwh);
if (r < 0)
- DMERR("register failed %d", r);
+ DMERR("Register failed %d.", r);
+ else {
+ kemchd = create_singlethread_workqueue("kemchd");
+ if (!kemchd) {
+ DMERR("Failed to create workqueue kemchd.");
+ dm_unregister_hw_handler(&emc_hwh);
+ return -ENOMEM;
+ }
+ }
- DMINFO("version 0.0.3 loaded");
+ DMINFO("Version 0.0.4 loaded.");
return r;
}
static void __exit dm_emc_exit(void)
{
- int r = dm_unregister_hw_handler(&emc_hwh);
+ int r;
+
+ destroy_workqueue(kemchd);
+ r = dm_unregister_hw_handler(&emc_hwh);
if (r < 0)
- DMERR("unregister failed %d", r);
+ DMERR("Unregister failed %d.", r);
}
module_init(dm_emc_init);
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