ore/exofs: Change the type of the devices array (API change)
In the pNFS obj-LD the device table at the layout level needs
to point to a device_cache node, where it is possible and likely
that many layouts will point to the same device-nodes.
In Exofs we have a more orderly structure where we have a single
array of devices that repeats twice for a round-robin view of the
device table
This patch moves to a model that can be used by the pNFS obj-LD
where struct ore_components holds an array of ore_dev-pointers.
(ore_dev is newly defined and contains a struct osd_dev *od
member)
Each pointer in the array of pointers will point to a bigger
user-defined dev_struct. That can be accessed by use of the
container_of macro.
In Exofs an __alloc_dev_table() function allocates the
ore_dev-pointers array as well as an exofs_dev array, in one
allocation and does the addresses dance to set everything pointing
correctly. It still keeps the double allocation trick for the
inodes round-robin view of the table.
The device table is always allocated dynamically, also for the
single device case. So it is unconditionally freed at umount.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/exofs.h b/fs/exofs/exofs.h
index 3b2e047..006fd6f 100644
--- a/fs/exofs/exofs.h
+++ b/fs/exofs/exofs.h
@@ -53,6 +53,10 @@
/* u64 has problems with printk this will cast it to unsigned long long */
#define _LLU(x) (unsigned long long)(x)
+struct exofs_dev {
+ struct ore_dev ored;
+ unsigned did;
+};
/*
* our extension to the in-memory superblock
*/
@@ -69,7 +73,6 @@
struct ore_layout layout; /* Default files layout */
struct ore_comp one_comp; /* id & cred of partition id=0*/
struct ore_components oc; /* comps for the partition */
- struct osd_dev *_min_one_dev[1]; /* Place holder for one dev */
};
/*
@@ -214,13 +217,14 @@
one_comp->obj.id = oid;
exofs_make_credential(one_comp->cred, &one_comp->obj);
- oc->numdevs = sbi->oc.numdevs;
+ oc->numdevs = sbi->layout.group_width * sbi->layout.mirrors_p1 *
+ sbi->layout.group_count;
oc->single_comp = EC_SINGLE_COMP;
oc->comps = one_comp;
/* Round robin device view of the table */
first_dev = (dev_mod * sbi->layout.mirrors_p1) % sbi->oc.numdevs;
- oc->ods = sbi->oc.ods + first_dev;
+ oc->ods = &sbi->oc.ods[first_dev];
}
#endif