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| author | Boaz Harrosh <bharrosh@panasas.com> | 2011-09-28 12:04:23 +0300 |
|---|---|---|
| committer | Boaz Harrosh <bharrosh@panasas.com> | 2011-10-14 18:54:41 +0200 |
| commit | 3bd9856857339d7ee8c4ad50030583f1b9415c39 (patch) | |
| tree | fa5d950b9beffa2a10bc698d452ae50b8e195d5e /include/scsi | |
| parent | bbf9a31bba8c985780fe94da059cc5813a7920f5 (diff) | |
| download | linux-stable-3bd9856857339d7ee8c4ad50030583f1b9415c39.tar.gz linux-stable-3bd9856857339d7ee8c4ad50030583f1b9415c39.tar.bz2 linux-stable-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.h | 7 |
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 { |