ore/exofs: Define new ore_verify_layout

[profile/ivi/kernel-adaptation-intel-automotive.git] / fs / exofs / ore.c

diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c
index f1b7180..4ca59d4 100644 (file)
--- a/fs/exofs/ore.c
+++ b/fs/exofs/ore.c
@@ -47,9 +47,76 @@ MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
 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;