Even though underlying paths are set with larger value for max_sectors, dm
sets 1024(i.e 512KB) for max_sectors as default. max_sectors for dm
device can be reset through sysfs but any time map is updated, max_sectors
is again set back to default. This patch gets the minimum of max_sectors from
physical paths and sets it to dm device.
Signed-off-by: Vijay Chauhan <vijay.chauhan@xxxxxxxxxx>
Reviewed-by: Babu Moger <babu.moger@xxxxxxxxxx>
Reviewed-by: Bob Stankey <Robert.Stankey@xxxxxxxxxx>
---
--- linux-3.5-rc5-orig/drivers/md/dm-table.c 2012-07-07 11:39:17.000000000 +0530
+++ linux-3.5-rc5/drivers/md/dm-table.c 2012-07-09 00:52:37.000000000 +0530
@@ -549,6 +549,18 @@ int dm_set_device_limits(struct dm_targe
}
EXPORT_SYMBOL_GPL(dm_set_device_limits);
+int dm_device_max_sectors(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ unsigned int *max_sectors = data;
+ struct block_device *bdev = dev->bdev;
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ *max_sectors = min_not_zero(*max_sectors, q->limits.max_sectors);
+
+ return 0;
+}
+
/*
* Decrement a device's use count and remove it if necessary.
*/
@@ -692,6 +704,7 @@ static int validate_hardware_logical_blo
struct dm_target *uninitialized_var(ti);
struct queue_limits ti_limits;
unsigned i = 0;
+ unsigned int max_sectors = 0;
/*
* Check each entry in the table in turn.
@@ -706,6 +719,15 @@ static int validate_hardware_logical_blo
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
+ /* Find minimum of max_sectors from target devices */
+ if (ti->type->iterate_devices) {
+ ti->type->iterate_devices(ti, dm_device_max_sectors,
+ &max_sectors);
+ limits->max_sectors = min_t(unsigned int,
+ ti_limits.max_hw_sectors,
+ max_sectors);
+ }
+
/*
* If the remaining sectors fall entirely within this
* table entry are they compatible with its logical_block_size?
--
--
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