Fixes for #6639

Several issues were uncovered by running stress tests with zfs
encryption and raw sends in particular. The issues and their
associated fixes are as follows:

* arc_read_done() has the ability to chain several requests for
  the same block of data via the arc_callback_t struct. In these
  cases, the ARC would only use the first request's dsobj from
  the bookmark to decrypt the data. This is problematic because
  the first request might be a prefetch zio which is able to
  handle the key not being loaded, while the second might use a
  different key that it is sure will work. The fix here is to
  pass the dsobj with each individual arc_callback_t so that each
  request can attempt to decrypt the data separately.

* DRR_FREE and DRR_FREEOBJECT records in a send file were not
  having their transactions properly tagged as raw during raw
  sends, which caused a panic when the dbuf code attempted to
  decrypt these blocks.

* traverse_prefetch_metadata() did not properly set
  ZIO_FLAG_SPECULATIVE when issuing prefetch IOs.

* Added a few asserts and code cleanups to ensure these issues
  are more detectable in the future.

Signed-off-by: Tom Caputi <[email protected]>

1 files changed, 8 insertions, 8 deletions

diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c
index d397d7279..248d04fc4 100644
--- a/cmd/ztest/ztest.c
+++ b/cmd/ztest/ztest.c
@@ -1958,7 +1958,7 @@ ztest_replay_write(ztest_ds_t *zd, lr_write_t *lr, boolean_t byteswap)
 		dmu_write(os, lr->lr_foid, offset, length, data, tx);
 	} else {
 		bcopy(data, abuf->b_data, length);
-		dmu_assign_arcbuf(db, offset, abuf, tx);
+		dmu_assign_arcbuf_by_dbuf(db, offset, abuf, tx);
 	}
 
 	(void) ztest_log_write(zd, tx, lr);
@@ -4346,7 +4346,7 @@ ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
 	 *	bigobj, at the tail of the nth chunk
 	 *
 	 * The chunk size is set equal to bigobj block size so that
-	 * dmu_assign_arcbuf() can be tested for object updates.
+	 * dmu_assign_arcbuf_by_dbuf() can be tested for object updates.
 	 */
 
 	/*
@@ -4408,7 +4408,7 @@ ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
 		/*
 		 * In iteration 5 (i == 5) use arcbufs
 		 * that don't match bigobj blksz to test
-		 * dmu_assign_arcbuf() when it can't directly
+		 * dmu_assign_arcbuf_by_dbuf() when it can't directly
 		 * assign an arcbuf to a dbuf.
 		 */
 		for (j = 0; j < s; j++) {
@@ -4454,8 +4454,8 @@ ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
 
 		/*
 		 * 50% of the time don't read objects in the 1st iteration to
-		 * test dmu_assign_arcbuf() for the case when there're no
-		 * existing dbufs for the specified offsets.
+		 * test dmu_assign_arcbuf_by_dbuf() for the case when there are
+		 * no existing dbufs for the specified offsets.
 		 */
 		if (i != 0 || ztest_random(2) != 0) {
 			error = dmu_read(os, packobj, packoff,
@@ -4500,12 +4500,12 @@ ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
 				    FTAG, &dbt, DMU_READ_NO_PREFETCH) == 0);
 			}
 			if (i != 5 || chunksize < (SPA_MINBLOCKSIZE * 2)) {
-				dmu_assign_arcbuf(bonus_db, off,
+				dmu_assign_arcbuf_by_dbuf(bonus_db, off,
 				    bigbuf_arcbufs[j], tx);
 			} else {
-				dmu_assign_arcbuf(bonus_db, off,
+				dmu_assign_arcbuf_by_dbuf(bonus_db, off,
 				    bigbuf_arcbufs[2 * j], tx);
-				dmu_assign_arcbuf(bonus_db,
+				dmu_assign_arcbuf_by_dbuf(bonus_db,
 				    off + chunksize / 2,
 				    bigbuf_arcbufs[2 * j + 1], tx);
 			}