5382 pvn_getpages handles lengths <= PAGESIZE just fine

*** 18,27 ****
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
   */
  
  #include <sys/param.h>
  #include <sys/types.h>
  #include <sys/systm.h>
*** 7383,7399 ****
                          if (seg != segkmap) {
                                  error = EFAULT;
                                  break;
                          }
                  }
!                 if (len <= PAGESIZE)
!                         error = cachefs_getapage(vp, (u_offset_t)off, len,
!                             protp, pl, plsz, seg, addr, rw, cr);
!                 else
!                         error = pvn_getpages(cachefs_getapage, vp,
!                             (u_offset_t)off, len, protp, pl, plsz, seg, addr,
!                             rw, cr);
                  if (error == 0)
                          break;
  
                  if (((cp->c_flags & CN_NOCACHE) && (error == ENOSPC)) ||
                      error == EAGAIN) {
--- 7384,7395 ----
                          if (seg != segkmap) {
                                  error = EFAULT;
                                  break;
                          }
                  }
!                 error = pvn_getpages(cachefs_getapage, vp, (u_offset_t)off,
!                     len, protp, pl, plsz, seg, addr, rw, cr);
                  if (error == 0)
                          break;
  
                  if (((cp->c_flags & CN_NOCACHE) && (error == ENOSPC)) ||
                      error == EAGAIN) {
*** 7409,7428 ****
                                  continue;
                          }
                  } else {
                          if (CFS_TIMEOUT(fscp, error)) {
                                  if (cachefs_cd_access_miss(fscp)) {
-                                         if (len <= PAGESIZE)
-                                                 error = cachefs_getapage_back(
-                                                     vp, (u_offset_t)off,
-                                                     len, protp, pl,
-                                                     plsz, seg, addr, rw, cr);
-                                         else
                                                  error = pvn_getpages(
                                                      cachefs_getapage_back, vp,
!                                                     (u_offset_t)off, len,
!                                                     protp, pl,
                                                      plsz, seg, addr, rw, cr);
                                          if (!CFS_TIMEOUT(fscp, error) &&
                                              (error != EAGAIN))
                                                  break;
                                          delay(5*hz);
--- 7405,7417 ----
                                  continue;
                          }
                  } else {
                          if (CFS_TIMEOUT(fscp, error)) {
                                  if (cachefs_cd_access_miss(fscp)) {
                                          error = pvn_getpages(
                                              cachefs_getapage_back, vp,
!                                             (u_offset_t)off, len, protp, pl,
                                              plsz, seg, addr, rw, cr);
                                          if (!CFS_TIMEOUT(fscp, error) &&
                                              (error != EAGAIN))
                                                  break;
                                          delay(5*hz);
*** 7496,7506 ****
  
          return (error);
  }
  
  /*
!  * Called from pvn_getpages or cachefs_getpage to get a particular page.
   */
  /*ARGSUSED*/
  static int
  cachefs_getapage(struct vnode *vp, u_offset_t off, size_t len, uint_t *protp,
          struct page *pl[], size_t plsz, struct seg *seg, caddr_t addr,
--- 7485,7495 ----
  
          return (error);
  }
  
  /*
!  * Called from pvn_getpages to get a particular page.
   */
  /*ARGSUSED*/
  static int
  cachefs_getapage(struct vnode *vp, u_offset_t off, size_t len, uint_t *protp,
          struct page *pl[], size_t plsz, struct seg *seg, caddr_t addr,