Commit 3bd98568 authored by Boaz Harrosh's avatar Boaz Harrosh
Browse files

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: default avatarBoaz Harrosh <bharrosh@panasas.com>
parent bbf9a31b

fs/exofs/exofs.h

+1 −0
Original line number Diff line number Diff line
@@ -217,6 +217,7 @@ static inline void exofs_init_comps(struct ore_components *oc, 
	one_comp->obj.id = oid;

	exofs_make_credential(one_comp->cred, &one_comp->obj);



	oc->first_dev = 0;

	oc->numdevs = sbi->layout.group_width * sbi->layout.mirrors_p1 *

							sbi->layout.group_count;

	oc->single_comp = EC_SINGLE_COMP;

fs/exofs/ore.c

+4 −0
Original line number Diff line number Diff line
@@ -62,6 +62,10 @@ static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index) 


static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)

{

	ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",

		    ios->oc->first_dev, ios->oc->numdevs, index,

		    ios->oc->ods);



	return ore_comp_dev(ios->oc, index);

}

include/scsi/osd_ore.h

+4 −3
Original line number Diff line number Diff line
@@ -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 {

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