6536 zfs send: want a way to disable sending of free records
Reviewed by: Alexander Stetsenko <astetsenko@racktopsystems.com>
Reviewed by: Kim Shrier <kshrier@racktopsystems.com>

*** 26,35 ****
--- 26,36 ----
   * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
   * Copyright (c) 2014, Joyent, Inc. All rights reserved.
   * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
   * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
   * Copyright (c) 2013 Steven Hartland. All rights reserved.
+  * Copyright 2015 RackTop Systems.
   */
  
  /*
   * ZFS ioctls.
   *
*** 4403,4412 ****
--- 4404,4414 ----
          int error;
          offset_t off;
          boolean_t estimate = (zc->zc_guid != 0);
          boolean_t embedok = (zc->zc_flags & 0x1);
          boolean_t large_block_ok = (zc->zc_flags & 0x2);
+         boolean_t skip_free = (zc->zc_flags & 0x4);
  
          if (zc->zc_obj != 0) {
                  dsl_pool_t *dp;
                  dsl_dataset_t *tosnap;
  
*** 4465,4475 ****
                          return (SET_ERROR(EBADF));
  
                  off = fp->f_offset;
                  error = dmu_send_obj(zc->zc_name, zc->zc_sendobj,
                      zc->zc_fromobj, embedok, large_block_ok,
!                     zc->zc_cookie, fp->f_vnode, &off);
  
                  if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                          fp->f_offset = off;
                  releasef(zc->zc_cookie);
          }
--- 4467,4477 ----
                          return (SET_ERROR(EBADF));
  
                  off = fp->f_offset;
                  error = dmu_send_obj(zc->zc_name, zc->zc_sendobj,
                      zc->zc_fromobj, embedok, large_block_ok,
!                     skip_free, zc->zc_cookie, fp->f_vnode, &off);
  
                  if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                          fp->f_offset = off;
                  releasef(zc->zc_cookie);
          }
*** 5394,5403 ****
--- 5396,5407 ----
   *     (optional) "fromsnap" -> full snap name to send an incremental from
   *     (optional) "largeblockok" -> (value ignored)
   *         indicates that blocks > 128KB are permitted
   *     (optional) "embedok" -> (value ignored)
   *         presence indicates DRR_WRITE_EMBEDDED records are permitted
+  *     (optional) "skipfree" -> (value ignored)
+  *         presence indicates free records should be omitted
   *     (optional) "resume_object" and "resume_offset" -> (uint64)
   *         if present, resume send stream from specified object and offset.
   * }
   *
   * outnvl is unused
*** 5410,5419 ****
--- 5414,5424 ----
          offset_t off;
          char *fromname = NULL;
          int fd;
          boolean_t largeblockok;
          boolean_t embedok;
+         boolean_t skipfree;
          uint64_t resumeobj = 0;
          uint64_t resumeoff = 0;
  
          error = nvlist_lookup_int32(innvl, "fd", &fd);
          if (error != 0)
*** 5421,5441 ****
  
          (void) nvlist_lookup_string(innvl, "fromsnap", &fromname);
  
          largeblockok = nvlist_exists(innvl, "largeblockok");
          embedok = nvlist_exists(innvl, "embedok");
  
          (void) nvlist_lookup_uint64(innvl, "resume_object", &resumeobj);
          (void) nvlist_lookup_uint64(innvl, "resume_offset", &resumeoff);
  
          file_t *fp = getf(fd);
          if (fp == NULL)
                  return (SET_ERROR(EBADF));
  
          off = fp->f_offset;
!         error = dmu_send(snapname, fromname, embedok, largeblockok, fd,
!             resumeobj, resumeoff, fp->f_vnode, &off);
  
          if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                  fp->f_offset = off;
          releasef(fd);
          return (error);
--- 5426,5447 ----
  
          (void) nvlist_lookup_string(innvl, "fromsnap", &fromname);
  
          largeblockok = nvlist_exists(innvl, "largeblockok");
          embedok = nvlist_exists(innvl, "embedok");
+         skipfree = nvlist_exists(innvl, "skipfree");
  
          (void) nvlist_lookup_uint64(innvl, "resume_object", &resumeobj);
          (void) nvlist_lookup_uint64(innvl, "resume_offset", &resumeoff);
  
          file_t *fp = getf(fd);
          if (fp == NULL)
                  return (SET_ERROR(EBADF));
  
          off = fp->f_offset;
!         error = dmu_send(snapname, fromname, embedok, largeblockok, skipfree,
!             fd, resumeobj, resumeoff, fp->f_vnode, &off);
  
          if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
                  fp->f_offset = off;
          releasef(fd);
          return (error);