ore/exofs: Define new ore_verify_layout
All users of the ore will need to check if current code
supports the given layout. For example RAID5/6 is not
currently supported.
So move all the checks from exofs/super.c to a new
ore_verify_layout() to be used by ore users.
Note that any new layout should be passed through the
ore_verify_layout() because the ore engine will prepare
and verify some internal members of ore_layout, and
assumes it's called.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c
index f1b7180..4ca59d4 100644
--- a/fs/exofs/ore.c
+++ b/fs/exofs/ore.c
@@ -47,9 +47,76 @@
MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
MODULE_LICENSE("GPL");
+/* ore_verify_layout does a couple of things:
+ * 1. Given a minimum number of needed parameters fixes up the rest of the
+ * members to be operatonals for the ore. The needed parameters are those
+ * that are defined by the pnfs-objects layout STD.
+ * 2. Check to see if the current ore code actually supports these parameters
+ * for example stripe_unit must be a multple of the system PAGE_SIZE,
+ * and etc...
+ * 3. Cache some havily used calculations that will be needed by users.
+ */
+
static void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
struct ore_striping_info *si);
+enum { BIO_MAX_PAGES_KMALLOC =
+ (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
+
+int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
+{
+ u64 stripe_length;
+
+/* FIXME: Only raid0 is supported for now. */
+ if (layout->raid_algorithm != PNFS_OSD_RAID_0) {
+ ORE_ERR("Only RAID_0 for now\n");
+ return -EINVAL;
+ }
+ if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
+ ORE_ERR("Stripe Unit(0x%llx)"
+ " must be Multples of PAGE_SIZE(0x%lx)\n",
+ _LLU(layout->stripe_unit), PAGE_SIZE);
+ return -EINVAL;
+ }
+ if (layout->group_width) {
+ if (!layout->group_depth) {
+ ORE_ERR("group_depth == 0 && group_width != 0\n");
+ return -EINVAL;
+ }
+ if (total_comps < (layout->group_width * layout->mirrors_p1)) {
+ ORE_ERR("Data Map wrong, "
+ "numdevs=%d < group_width=%d * mirrors=%d\n",
+ total_comps, layout->group_width,
+ layout->mirrors_p1);
+ return -EINVAL;
+ }
+ layout->group_count = total_comps / layout->mirrors_p1 /
+ layout->group_width;
+ } else {
+ if (layout->group_depth) {
+ printk(KERN_NOTICE "Warning: group_depth ignored "
+ "group_width == 0 && group_depth == %lld\n",
+ _LLU(layout->group_depth));
+ }
+ layout->group_width = total_comps / layout->mirrors_p1;
+ layout->group_depth = -1;
+ layout->group_count = 1;
+ }
+
+ stripe_length = (u64)layout->group_width * layout->stripe_unit;
+ if (stripe_length >= (1ULL << 32)) {
+ ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
+ _LLU(stripe_length));
+ return -EINVAL;
+ }
+
+ layout->max_io_length =
+ (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
+ layout->group_width;
+ return 0;
+}
+EXPORT_SYMBOL(ore_verify_layout);
+
static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
{
return ios->oc->comps[index & ios->oc->single_comp].cred;