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/super.c b/fs/exofs/super.c
index 90b4c52..bce3686 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -431,17 +431,18 @@
static void exofs_free_sbi(struct exofs_sb_info *sbi)
{
- while (sbi->oc.numdevs) {
- int i = --sbi->oc.numdevs;
- struct osd_dev *od = sbi->oc.ods[i];
+ unsigned numdevs = sbi->oc.numdevs;
+
+ while (numdevs) {
+ unsigned i = --numdevs;
+ struct osd_dev *od = ore_comp_dev(&sbi->oc, i);
if (od) {
- sbi->oc.ods[i] = NULL;
+ ore_comp_set_dev(&sbi->oc, i, NULL);
osduld_put_device(od);
}
}
- if (sbi->oc.ods != sbi->_min_one_dev)
- kfree(sbi->oc.ods);
+ kfree(sbi->oc.ods);
kfree(sbi);
}
@@ -468,7 +469,7 @@
msecs_to_jiffies(100));
}
- _exofs_print_device("Unmounting", NULL, sbi->oc.ods[0],
+ _exofs_print_device("Unmounting", NULL, ore_comp_dev(&sbi->oc, 0),
sbi->one_comp.obj.partition);
bdi_destroy(&sbi->bdi);
@@ -592,12 +593,40 @@
return !(odi->systemid_len || odi->osdname_len);
}
+int __alloc_dev_table(struct exofs_sb_info *sbi, unsigned numdevs,
+ struct exofs_dev **peds)
+{
+ struct __alloc_ore_devs_and_exofs_devs {
+ /* Twice bigger table: See exofs_init_comps() and comment at
+ * exofs_read_lookup_dev_table()
+ */
+ struct ore_dev *oreds[numdevs * 2 - 1];
+ struct exofs_dev eds[numdevs];
+ } *aoded;
+ struct exofs_dev *eds;
+ unsigned i;
+
+ aoded = kzalloc(sizeof(*aoded), GFP_KERNEL);
+ if (unlikely(!aoded)) {
+ EXOFS_ERR("ERROR: faild allocating Device array[%d]\n",
+ numdevs);
+ return -ENOMEM;
+ }
+
+ sbi->oc.ods = aoded->oreds;
+ *peds = eds = aoded->eds;
+ for (i = 0; i < numdevs; ++i)
+ aoded->oreds[i] = &eds[i].ored;
+ return 0;
+}
+
static int exofs_read_lookup_dev_table(struct exofs_sb_info *sbi,
struct osd_dev *fscb_od,
unsigned table_count)
{
struct ore_comp comp;
struct exofs_device_table *dt;
+ struct exofs_dev *eds;
unsigned table_bytes = table_count * sizeof(dt->dt_dev_table[0]) +
sizeof(*dt);
unsigned numdevs, i;
@@ -634,20 +663,16 @@
if (unlikely(ret))
goto out;
- if (likely(numdevs > 1)) {
- unsigned size = numdevs * sizeof(sbi->oc.ods[0]);
-
- /* Twice bigger table: See exofs_init_comps() and below
- * comment
- */
- sbi->oc.ods = kzalloc(size + size - 1, GFP_KERNEL);
- if (unlikely(!sbi->oc.ods)) {
- EXOFS_ERR("ERROR: faild allocating Device array[%d]\n",
- numdevs);
- ret = -ENOMEM;
- goto out;
- }
- }
+ ret = __alloc_dev_table(sbi, numdevs, &eds);
+ if (unlikely(ret))
+ goto out;
+ /* exofs round-robins the device table view according to inode
+ * number. We hold a: twice bigger table hence inodes can point
+ * to any device and have a sequential view of the table
+ * starting at this device. See exofs_init_comps()
+ */
+ memcpy(&sbi->oc.ods[numdevs], &sbi->oc.ods[0],
+ (numdevs - 1) * sizeof(sbi->oc.ods[0]));
for (i = 0; i < numdevs; i++) {
struct exofs_fscb fscb;
@@ -663,12 +688,15 @@
printk(KERN_NOTICE "Add device[%d]: osd_name-%s\n",
i, odi.osdname);
+ /* the exofs id is currently the table index */
+ eds[i].did = i;
+
/* On all devices the device table is identical. The user can
* specify any one of the participating devices on the command
* line. We always keep them in device-table order.
*/
if (fscb_od && osduld_device_same(fscb_od, &odi)) {
- sbi->oc.ods[i] = fscb_od;
+ eds[i].ored.od = fscb_od;
++sbi->oc.numdevs;
fscb_od = NULL;
continue;
@@ -682,7 +710,7 @@
goto out;
}
- sbi->oc.ods[i] = od;
+ eds[i].ored.od = od;
++sbi->oc.numdevs;
/* Read the fscb of the other devices to make sure the FS
@@ -705,21 +733,10 @@
out:
kfree(dt);
- if (likely(!ret)) {
- unsigned numdevs = sbi->oc.numdevs;
-
- if (unlikely(fscb_od)) {
+ if (unlikely(fscb_od && !ret)) {
EXOFS_ERR("ERROR: Bad device-table container device not present\n");
osduld_put_device(fscb_od);
return -EINVAL;
- }
- /* exofs round-robins the device table view according to inode
- * number. We hold a: twice bigger table hence inodes can point
- * to any device and have a sequential view of the table
- * starting at this device. See exofs_init_comps()
- */
- for (i = 0; i < numdevs - 1; ++i)
- sbi->oc.ods[i + numdevs] = sbi->oc.ods[i];
}
return ret;
}
@@ -773,7 +790,6 @@
sbi->oc.numdevs = 1;
sbi->oc.single_comp = EC_SINGLE_COMP;
sbi->oc.comps = &sbi->one_comp;
- sbi->oc.ods = sbi->_min_one_dev;
/* fill in some other data by hand */
memset(sb->s_id, 0, sizeof(sb->s_id));
@@ -822,7 +838,13 @@
if (unlikely(ret))
goto free_sbi;
} else {
- sbi->oc.ods[0] = od;
+ struct exofs_dev *eds;
+
+ ret = __alloc_dev_table(sbi, 1, &eds);
+ if (unlikely(ret))
+ goto free_sbi;
+
+ ore_comp_set_dev(&sbi->oc, 0, od);
}
__sbi_read_stats(sbi);
@@ -862,7 +884,8 @@
goto free_sbi;
}
- _exofs_print_device("Mounting", opts->dev_name, sbi->oc.ods[0],
+ _exofs_print_device("Mounting", opts->dev_name,
+ ore_comp_dev(&sbi->oc, 0),
sbi->one_comp.obj.partition);
return 0;