LU-4865 zfs: grow block size by write pattern

[fs/lustre-release.git] / lustre / osd-zfs / osd_io.c

diff --git a/lustre/osd-zfs/osd_io.c b/lustre/osd-zfs/osd_io.c
index a6b6cea..eed35f5 100644 (file)
--- a/lustre/osd-zfs/osd_io.c
+++ b/lustre/osd-zfs/osd_io.c
@@ -682,6 +682,68 @@ retry:
        RETURN(rc);
 }
 
+/**
+ * Policy to grow ZFS block size by write pattern.
+ * For sequential write, it grows block size gradually until it reaches the
+ * maximum blocksize the dataset can support. Otherwise, it will pick a
+ * a block size by the writing region of this I/O.
+ */
+static int osd_grow_blocksize(struct osd_object *obj, struct osd_thandle *oh,
+                             uint64_t start, uint64_t end)
+{
+       struct osd_device       *osd = osd_obj2dev(obj);
+       dmu_buf_impl_t          *db = (dmu_buf_impl_t *)obj->oo_db;
+       dnode_t                 *dn;
+       uint32_t                 blksz;
+       int                      rc = 0;
+
+       ENTRY;
+
+       DB_DNODE_ENTER(db);
+       dn = DB_DNODE(db);
+
+       if (dn->dn_maxblkid > 0) /* can't change block size */
+               GOTO(out, rc);
+
+       if (dn->dn_datablksz >= osd->od_max_blksz)
+               GOTO(out, rc);
+
+       down_write(&obj->oo_guard);
+
+       blksz = dn->dn_datablksz;
+       if (blksz >= osd->od_max_blksz) /* check again after grabbing lock */
+               GOTO(out_unlock, rc);
+
+       /* now ZFS can support up to 16MB block size, and if the write
+        * is sequential, it just increases the block size gradually */
+       if (start <= blksz) { /* sequential */
+               blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz, end);
+       } else { /* sparse, pick a block size by write region */
+               blksz = (uint32_t)min_t(uint64_t, osd->od_max_blksz,
+                                       end - start);
+       }
+
+       if (!is_power_of_2(blksz))
+               blksz = size_roundup_power2(blksz);
+
+       if (blksz > dn->dn_datablksz) {
+               rc = -dmu_object_set_blocksize(osd->od_os, dn->dn_object,
+                                              blksz, 0, oh->ot_tx);
+               LASSERT(ergo(rc == 0, dn->dn_datablksz >= blksz));
+               if (rc < 0)
+                       CDEBUG(D_INODE, "object "DFID": change block size"
+                              "%u -> %u error rc = %d\n",
+                              PFID(lu_object_fid(&obj->oo_dt.do_lu)),
+                              dn->dn_datablksz, blksz, rc);
+       }
+       EXIT;
+out_unlock:
+       up_write(&obj->oo_guard);
+out:
+       DB_DNODE_EXIT(db);
+       return rc;
+}
+
 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
                        struct niobuf_local *lnb, int npages,
                        struct thandle *th)
@@ -700,6 +762,10 @@ static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
        LASSERT(th != NULL);
        oh = container_of0(th, struct osd_thandle, ot_super);
 
+       /* adjust block size. Assume the buffers are sorted. */
+       (void)osd_grow_blocksize(obj, oh, lnb[0].lnb_file_offset,
+                                lnb[npages - 1].lnb_file_offset +
+                                lnb[npages - 1].lnb_len);
        for (i = 0; i < npages; i++) {
                CDEBUG(D_INODE, "write %u bytes at %u\n",
                        (unsigned) lnb[i].lnb_len,