LU-11691 lov: Limit layout size to max ea size

[fs/lustre-release.git] / lustre / lod / lod_qos.c

diff --git a/lustre/lod/lod_qos.c b/lustre/lod/lod_qos.c
index f840150..3749b38 100644 (file)
--- a/lustre/lod/lod_qos.c
+++ b/lustre/lod/lod_qos.c
@@ -1732,12 +1732,15 @@ out_nolock:
 }
 
 /**
- * Find largest stripe count the caller can use.
+ * Check stripe count the caller can use.
  *
+ * For new layouts (no initialized components), check the total size of the
+ * layout against the maximum EA size from the backing file system.  This
+ * stops us from creating a layout which will be too large once initialized.
+ *
+ * For existing layouts (with initialized components):
  * Find the maximal possible stripe count not greater than \a stripe_count.
- * Sometimes suggested stripecount can't be reached for a number of reasons:
- * lack of enough active OSTs or the backend does not support EAs that large.
- * If the passed one is 0, then the filesystem's default one is used.
+ * If the provided stripe count is 0, then the filesystem's default is used.
  *
  * \param[in] lod      LOD device
  * \param[in] lo       The lod_object
@@ -1749,6 +1752,10 @@ __u16 lod_get_stripe_count(struct lod_device *lod, struct lod_object *lo,
                           __u16 stripe_count)
 {
        __u32 max_stripes = LOV_MAX_STRIPE_COUNT_OLD;
+       /* max stripe count is based on OSD ea size */
+       unsigned int easize = lod->lod_osd_max_easize;
+       int i;
+
 
        if (!stripe_count)
                stripe_count = lod->lod_desc.ld_default_stripe_count;
@@ -1757,33 +1764,38 @@ __u16 lod_get_stripe_count(struct lod_device *lod, struct lod_object *lo,
        if (!stripe_count)
                stripe_count = 1;
 
-       /* stripe count is based on whether OSD can handle larger EA sizes */
-       if (lod->lod_osd_max_easize > 0) {
-               unsigned int easize = lod->lod_osd_max_easize;
-               int i;
-
-               if (lo->ldo_is_composite) {
-                       struct lod_layout_component *lod_comp;
-                       unsigned int header_sz = sizeof(struct lov_comp_md_v1);
-
-                       header_sz += sizeof(struct lov_comp_md_entry_v1) *
-                                       lo->ldo_comp_cnt;
-                       for (i = 0; i < lo->ldo_comp_cnt; i++) {
-                               lod_comp = &lo->ldo_comp_entries[i];
-                               if (lod_comp->llc_flags & LCME_FL_INIT)
-                                       header_sz += lov_mds_md_size(
-                                               lod_comp->llc_stripe_count,
-                                               LOV_MAGIC_V3);
-                       }
-                       if (easize > header_sz)
-                               easize -= header_sz;
-                       else
-                               easize = 0;
+       if (lo->ldo_is_composite) {
+               struct lod_layout_component *lod_comp;
+               unsigned int header_sz = sizeof(struct lov_comp_md_v1);
+               unsigned int init_comp_sz = 0;
+               unsigned int total_comp_sz = 0;
+               unsigned int comp_sz;
+
+               header_sz += sizeof(struct lov_comp_md_entry_v1) *
+                               lo->ldo_comp_cnt;
+
+               for (i = 0; i < lo->ldo_comp_cnt; i++) {
+                       lod_comp = &lo->ldo_comp_entries[i];
+                       comp_sz = lov_mds_md_size(lod_comp->llc_stripe_count,
+                                                 LOV_MAGIC_V3);
+                       total_comp_sz += comp_sz;
+                       if (lod_comp->llc_flags & LCME_FL_INIT)
+                               init_comp_sz += comp_sz;
                }
 
-               max_stripes = lov_mds_md_max_stripe_count(easize, LOV_MAGIC_V3);
+               if (init_comp_sz > 0)
+                       total_comp_sz = init_comp_sz;
+
+               header_sz += total_comp_sz;
+
+               if (easize > header_sz)
+                       easize -= header_sz;
+               else
+                       easize = 0;
        }
 
+       max_stripes = lov_mds_md_max_stripe_count(easize, LOV_MAGIC_V3);
+
        return (stripe_count < max_stripes) ? stripe_count : max_stripes;
 }