convert blk_rq_map_kern so it does not have to allocate a page
and use GFP_KERNEL.
TODO: fixup mempool problems.
This patch was made against 2.6.12-rc5 and works with scsi-misc.
Sorry I did not do dm unstable. The patch is only compile tested.
--- linux-2.6.12-rc5.orig/drivers/md/dm-emc.c 2005-06-03 03:23:46.000000000 -0700
+++ linux-2.6.12-rc5/drivers/md/dm-emc.c 2005-06-03 15:38:09.000000000 -0700
@@ -28,95 +28,80 @@ struct emc_handler {
#define TRESPASS_PAGE 0x22
#define EMC_FAILOVER_TIMEOUT (60 * HZ)
-/* Code borrowed from dm-lsi-rdac by Mike Christie */
+static unsigned char emc_long_trespass[] = {
+ 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 */
+};
-static inline void free_bio(struct bio *bio)
-{
- __free_page(bio->bi_io_vec[0].bv_page);
- bio_put(bio);
-}
+static unsigned char emc_long_trespass_hr[] = {
+ 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 */
+};
-static int emc_endio(struct bio *bio, unsigned int bytes_done, int error)
-{
- struct path *path = bio->bi_private;
+static unsigned char emc_short_trespass[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x02, /* Page length - 2 */
+ 0x81, /* Trespass code + Honor reservation bit */
+ 0xff, /* Trespass target */
+};
- if (bio->bi_size)
- return 1;
+static unsigned char emc_short_trespass_hr[] = {
+ 0, 0, 0, 0,
+ TRESPASS_PAGE, /* Page code */
+ 0x02, /* Page length - 2 */
+ 0x01, /* Trespass code + Honor reservation bit */
+ 0xff, /* Trespass target */
+};
+
+/* Code borrowed from dm-lsi-rdac by Mike Christie */
+
+static void emc_endio(struct request *rq)
+{
+ struct path *path = rq->end_io_data;
/* 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)
+ if (rq->errors)
dm_pg_init_complete(path, MP_FAIL_PATH);
else
dm_pg_init_complete(path, 0);
- /* request is freed in block layer */
- free_bio(bio);
-
- return 0;
-}
-
-static struct bio *get_failover_bio(struct path *path, unsigned data_size)
-{
- struct bio *bio;
- struct page *page;
-
- bio = bio_alloc(GFP_ATOMIC, 1);
- if (!bio) {
- DMERR("dm-emc: get_failover_bio: bio_alloc() failed.");
- return NULL;
- }
-
- 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("dm-emc: get_failover_bio: alloc_page() failed.");
- bio_put(bio);
- return NULL;
- }
-
- if (bio_add_page(bio, page, data_size, 0) != data_size) {
- DMERR("dm-emc: get_failover_bio: alloc_page() failed.");
- __free_page(page);
- bio_put(bio);
- return NULL;
- }
-
- return bio;
+ blk_put_request(rq);
}
static struct request *get_failover_req(struct emc_handler *h,
- struct bio *bio, struct path *path)
+ struct path *path, unsigned char *data,
+ unsigned data_size)
{
struct request *rq;
- struct block_device *bdev = bio->bi_bdev;
+ struct block_device *bdev = path->dev->bdev;
struct request_queue *q = bdev_get_queue(bdev);
/* FIXME: Figure out why it fails with GFP_ATOMIC. */
- rq = blk_get_request(q, WRITE, __GFP_WAIT);
- if (!rq) {
+ rq = blk_rq_map_kern(q, WRITE, data, data_size, __GFP_WAIT);
+ if (IS_ERR(rq)) {
DMERR("dm-emc: get_failover_req: blk_get_request failed");
return NULL;
}
- rq->bio = rq->biotail = bio;
- blk_rq_bio_prep(q, rq, bio);
-
+ /*
+ * do we need to bounce or will data be within the limits magically?
+ */
+ rq->end_io = emc_endio;
+ rq->end_io_data = path;
rq->rq_disk = bdev->bd_contains->bd_disk;
-
- /* 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;
-
rq->sense = h->sense;
memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
rq->sense_len = 0;
@@ -132,49 +117,22 @@ static struct request *get_failover_req(
static struct request *emc_trespass_get(struct emc_handler *h,
struct path *path)
{
- struct bio *bio;
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;
+ unsigned data_size;
- bio = get_failover_bio(path, data_size);
- if (!bio) {
- DMERR("dm-emc: emc_trespass_get: no bio");
- return NULL;
+ if (h->short_trespass) {
+ page22 = h->hr ? emc_short_trespass_hr : emc_short_trespass;
+ data_size = sizeof(emc_short_trespass);
+ } else {
+ page22 = h->hr ? emc_long_trespass_hr : emc_long_trespass;
+ data_size = sizeof(emc_long_trespass);
}
- 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 request for block layer packet command */
- rq = get_failover_req(h, bio, path);
+ rq = get_failover_req(h, path, page22, data_size);
if (!rq) {
DMERR("dm-emc: emc_trespass_get: no rq");
- free_bio(bio);
return NULL;
}
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