XXXX give me a better summary

*** 2024,2036 ****
          /*
           * Only reason putapage is going to give us SE_NOSWAP as error
           * is when we ask a page to be written to physical backing store
           * and there is none. Ignore this because we might be dealing
           * with a swap page which does not have any backing store
!          * on disk. In any other case we won't get this error over here.
           */
!         if (err == SE_NOSWAP)
                  err = 0;
          return (err);
  }
  
  long tmp_putpagecnt, tmp_pagespushed;
--- 2024,2037 ----
          /*
           * Only reason putapage is going to give us SE_NOSWAP as error
           * is when we ask a page to be written to physical backing store
           * and there is none. Ignore this because we might be dealing
           * with a swap page which does not have any backing store
!          * on disk, though the newer SE_NODEV error should cover that.
!          * In any other case we won't get this error over here.
           */
!         if (err == SE_NOSWAP || err == SE_NODEV)
                  err = 0;
          return (err);
  }
  
  long tmp_putpagecnt, tmp_pagespushed;
*** 2089,2107 ****
          io_off = pp_off;
          io_len = pp_len;
          err = swap_newphysname(vp, offset, &io_off, &io_len, &pvp, &pstart);
          ASSERT(err != SE_NOANON); /* anon slot must have been filled */
          if (err) {
!                 pvn_write_done(pplist, B_ERROR | B_WRITE | flags);
                  /*
                   * If this routine is called as a result of segvn_sync
                   * operation and we have no physical swap then we can get an
                   * error here. In such case we would return SE_NOSWAP as error.
-                  * At this point, we expect only SE_NOSWAP.
                   */
!                 ASSERT(err == SE_NOSWAP);
!                 if (flags & B_INVAL)
                          err = ENOMEM;
                  goto out;
          }
          ASSERT(pp_off <= io_off && io_off + io_len <= pp_off + pp_len);
          ASSERT(io_off <= offset && offset < io_off + io_len);
--- 2090,2108 ----
          io_off = pp_off;
          io_len = pp_len;
          err = swap_newphysname(vp, offset, &io_off, &io_len, &pvp, &pstart);
          ASSERT(err != SE_NOANON); /* anon slot must have been filled */
          if (err) {
!                 ASSERT(err == SE_NOSWAP || err == SE_NODEV);
!                 pvn_write_done(pplist, (err == SE_NODEV ? 0 : B_ERROR) |
!                     B_WRITE | flags);
                  /*
                   * If this routine is called as a result of segvn_sync
                   * operation and we have no physical swap then we can get an
                   * error here. In such case we would return SE_NOSWAP as error.
                   */
!                 if ((flags & B_INVAL) && err == SE_NOSWAP)
                          err = ENOMEM;
                  goto out;
          }
          ASSERT(pp_off <= io_off && io_off + io_len <= pp_off + pp_len);
          ASSERT(io_off <= offset && offset < io_off + io_len);
*** 2141,2151 ****
                  if (lenp)
                          *lenp = io_len;
                  tmp_putpagecnt++;
                  tmp_pagespushed += btop(io_len);
          }
!         if (err && err != ENOMEM && err != SE_NOSWAP)
                  cmn_err(CE_WARN, "tmp_putapage: err %d\n", err);
          return (err);
  }
  
  /* ARGSUSED */
--- 2142,2152 ----
                  if (lenp)
                          *lenp = io_len;
                  tmp_putpagecnt++;
                  tmp_pagespushed += btop(io_len);
          }
!         if (err && err != ENOMEM && err != SE_NOSWAP && err != SE_NODEV)
                  cmn_err(CE_WARN, "tmp_putapage: err %d\n", err);
          return (err);
  }
  
  /* ARGSUSED */