I am not sure if the first mail got sent out. Here is
the correct mail with the patch.
Hey Lars,
Here is what I meant. A Page for just something around 8-16 bytes
seems wasteful. Plus there is no reserve.
If you have to end up setting more bits maybe it is better to
preallocate a command per device at create time, or maybe since
there are four different combos I should have done it with this
patch?
This was made against 2.6.12-rc2. Only compile tested.
Mike
--- linux-2.6.12-rc2/drivers/md/dm-emc.c.orig 2005-04-11 03:09:20.000000000 -0700
+++ linux-2.6.12-rc2/drivers/md/dm-emc.c 2005-04-11 04:27:08.000000000 -0700
@@ -28,13 +28,41 @@ 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 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 */
+};
+
+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 int emc_endio(struct bio *bio, unsigned int bytes_done, int error)
{
@@ -54,15 +82,15 @@ static int emc_endio(struct bio *bio, un
dm_pg_init_complete(path, 0);
/* request is freed in block layer */
- free_bio(bio);
+ bio_put(bio);
return 0;
}
-static struct bio *get_failover_bio(struct path *path, unsigned data_size)
+static struct bio *get_failover_bio(struct path *path, unsigned char *data,
+ unsigned data_size)
{
struct bio *bio;
- struct page *page;
bio = bio_alloc(GFP_ATOMIC, 1);
if (!bio) {
@@ -76,20 +104,13 @@ static struct bio *get_failover_bio(stru
bio->bi_private = path;
bio->bi_end_io = emc_endio;
- page = alloc_page(GFP_ATOMIC);
- if (!page) {
+ if (bio_add_page(bio, virt_to_page(data), data_size,
+ offset_in_page(data)) != data_size) {
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;
}
@@ -135,46 +156,27 @@ static struct request *emc_trespass_get(
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 (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);
+ }
+
+ bio = get_failover_bio(path, page22, data_size);
if (!bio) {
DMERR("dm-emc: 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 request for block layer packet command */
rq = get_failover_req(h, bio, path);
if (!rq) {
DMERR("dm-emc: emc_trespass_get: no rq");
- free_bio(bio);
+ bio_put(bio);
return NULL;
}
