[PATCH 002 of 11] md: Remove arbitrary limit on chunk size.

NeilBrown
2006-05-01T05:30:42Z

The largest chunk size the code can support without substantial
surgery is 2^30 bytes, so make that the limit instead of an arbitrary
4Meg.
Some day, the 'chunksize' should change to a sector-shift
instead of a byte-count. Then no limit would be needed.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./drivers/md/raid10.c | 2 +-
./drivers/md/raid5.c | 4 ++--
./drivers/md/raid6main.c | 4 ++--
./include/linux/raid/md_k.h | 3 ++-
4 files changed, 7 insertions(+), 6 deletions(-)

diff ./drivers/md/raid10.c~current~ ./drivers/md/raid10.c
--- ./drivers/md/raid10.c~current~ 2006-05-01 15:09:20.000000000 +1000
+++ ./drivers/md/raid10.c 2006-05-01 15:10:17.000000000 +1000
@@ -2050,7 +2050,7 @@ static int run(mddev_t *mddev)
* maybe...
*/
{
- int stripe = conf->raid_disks * mddev->chunk_size / PAGE_SIZE;
+ int stripe = conf->raid_disks * (mddev->chunk_size / PAGE_SIZE);
stripe /= conf->near_copies;
if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
mddev->queue->backing_dev_info.ra_pages = 2* stripe;

diff ./drivers/md/raid5.c~current~ ./drivers/md/raid5.c
--- ./drivers/md/raid5.c~current~ 2006-05-01 15:09:20.000000000 +1000
+++ ./drivers/md/raid5.c 2006-05-01 15:10:17.000000000 +1000
@@ -2382,8 +2382,8 @@ static int run(mddev_t *mddev)
* 2 * (n-1) * chunksize where 'n' is the number of raid devices
*/
{
- int stripe = (mddev->raid_disks-1) * mddev->chunk_size
- / PAGE_SIZE;
+ int stripe = (mddev->raid_disks-1) *
+ (mddev->chunk_size / PAGE_SIZE);
if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
}

diff ./drivers/md/raid6main.c~current~ ./drivers/md/raid6main.c
--- ./drivers/md/raid6main.c~current~ 2006-05-01 15:09:20.000000000 +1000
+++ ./drivers/md/raid6main.c 2006-05-01 15:10:17.000000000 +1000
@@ -2135,8 +2135,8 @@ static int run(mddev_t *mddev)
* 2 * (n-2) * chunksize where 'n' is the number of raid devices
*/
{
- int stripe = (mddev->raid_disks-2) * mddev->chunk_size
- / PAGE_SIZE;
+ int stripe = (mddev->raid_disks-2) *
+ (mddev->chunk_size / PAGE_SIZE);
if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
}

diff ./include/linux/raid/md_k.h~current~ ./include/linux/raid/md_k.h
--- ./include/linux/raid/md_k.h~current~ 2006-05-01 15:09:20.000000000 +1000
+++ ./include/linux/raid/md_k.h 2006-05-01 15:10:17.000000000 +1000
@@ -40,7 +40,8 @@ typedef struct mdk_rdev_s mdk_rdev_t;
* options passed in raidrun:
*/

-#define MAX_CHUNK_SIZE (4096*1024)
+/* Currently this must fix in an 'int' */
+#define MAX_CHUNK_SIZE (1<<30)

/*
* MD's 'extended' device