LU-9305 osd-zfs: arc_buf could be non-pagesize aligned

[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 94eee7d..a74e58c 100644 (file)
--- a/lustre/osd-zfs/osd_io.c
+++ b/lustre/osd-zfs/osd_io.c
@@ -278,6 +278,7 @@ static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
 
 static inline struct page *kmem_to_page(void *addr)
 {
+       LASSERT(!((unsigned long)addr & ~PAGE_MASK));
        if (is_vmalloc_addr(addr))
                return vmalloc_to_page(addr);
        else
@@ -388,6 +389,29 @@ err:
        RETURN(rc);
 }
 
+static inline arc_buf_t *osd_request_arcbuf(dnode_t *dn, size_t bs)
+{
+       arc_buf_t *abuf;
+
+       abuf = dmu_request_arcbuf(&dn->dn_bonus->db, bs);
+       if (unlikely(!abuf))
+               return ERR_PTR(-ENOMEM);
+
+#if ZFS_VERSION_CODE < OBD_OCD_VERSION(0, 7, 0, 0)
+       /**
+        * ZFS prior to 0.7.0 doesn't guarantee PAGE_SIZE alignment for zio
+        * blocks smaller than (PAGE_SIZE << 2). This poses a problem of
+        * setting up page array for RDMA transfer. See LU-9305.
+        */
+       if ((unsigned long)abuf->b_data & ~PAGE_MASK) {
+               dmu_return_arcbuf(abuf);
+               return NULL;
+       }
+#endif
+
+       return abuf;
+}
+
 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
                                loff_t off, ssize_t len, struct niobuf_local *lnb)
 {
@@ -409,13 +433,15 @@ static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
                off_in_block = off & (bs - 1);
                sz_in_block = min_t(int, bs - off_in_block, len);
 
+               abuf = NULL;
                if (sz_in_block == bs) {
                        /* full block, try to use zerocopy */
+                       abuf = osd_request_arcbuf(dn, bs);
+                       if (unlikely(IS_ERR(abuf)))
+                               GOTO(out_err, rc = PTR_ERR(abuf));
+               }
 
-                       abuf = dmu_request_arcbuf(&dn->dn_bonus->db, bs);
-                       if (unlikely(abuf == NULL))
-                               GOTO(out_err, rc = -ENOMEM);
-
+               if (abuf != NULL) {
                        atomic_inc(&osd->od_zerocopy_loan);
 
                        /* go over pages arcbuf contains, put them as