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authorBoaz Harrosh <bharrosh@panasas.com>2011-09-28 11:04:23 +0200
committerBoaz Harrosh <bharrosh@panasas.com>2011-10-14 18:54:41 +0200
commit3bd9856857339d7ee8c4ad50030583f1b9415c39 (patch)
treefa5d950b9beffa2a10bc698d452ae50b8e195d5e /include/scsi
parentore: Support for short read/writes (diff)
downloadlinux-3bd9856857339d7ee8c4ad50030583f1b9415c39.tar.xz
linux-3bd9856857339d7ee8c4ad50030583f1b9415c39.zip
ore: Support for partial component table
Users like the objlayout-driver would like to only pass a partial device table that covers the IO in question. For example exofs divides the file into raid-group-sized chunks and only serves group_width number of devices at a time. The partiality is communicated by setting ore_componets->first_dev and the array covers all logical devices from oc->first_dev upto (oc->first_dev + oc->numdevs) The ore_comp_dev() API receives a logical device index and returns the actual present device in the table. An out-of-range dev_index will BUG. Logical device index is the theoretical device index as if all the devices of a file are present. .i.e: total_devs = group_width * mirror_p1 * group_count 0 <= dev_index < total_devs Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Diffstat (limited to 'include/scsi')
-rw-r--r--include/scsi/osd_ore.h7
1 files changed, 4 insertions, 3 deletions
diff --git a/include/scsi/osd_ore.h b/include/scsi/osd_ore.h
index baeef0200a1f..492b70d43bb6 100644
--- a/include/scsi/osd_ore.h
+++ b/include/scsi/osd_ore.h
@@ -49,6 +49,7 @@ struct ore_dev {
};
struct ore_components {
+ unsigned first_dev; /* First logical device no */
unsigned numdevs; /* Num of devices in array */
/* If @single_comp == EC_SINGLE_COMP, @comps points to a single
* component. else there are @numdevs components
@@ -70,14 +71,14 @@ struct ore_components {
static inline struct osd_dev *ore_comp_dev(
const struct ore_components *oc, unsigned i)
{
- BUG_ON(oc->numdevs <= i);
- return oc->ods[i]->od;
+ BUG_ON((i < oc->first_dev) || (oc->first_dev + oc->numdevs <= i));
+ return oc->ods[i - oc->first_dev]->od;
}
static inline void ore_comp_set_dev(
struct ore_components *oc, unsigned i, struct osd_dev *od)
{
- oc->ods[i]->od = od;
+ oc->ods[i - oc->first_dev]->od = od;
}
struct ore_striping_info {