X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fdmu_tx.c;h=81c86dff43d6bebf47476b892988b9a0b3ae1828;hb=5853fe790d1df58c5dd85ea52c5e165b6d43013c;hp=47ec4c1091e8c467373fb837f06de978fbd10442;hpb=9ae529ec5dbdc828ff8326beae58062971d74b2e;p=zfs.git

diff --git a/module/zfs/dmu_tx.c b/module/zfs/dmu_tx.c
index 47ec4c1..81c86df 100644
--- a/module/zfs/dmu_tx.c
+++ b/module/zfs/dmu_tx.c
@@ -21,7 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 #include <sys/dmu.h>
@@ -301,6 +301,7 @@ dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 			delta = P2NPHASE(off, dn->dn_datablksz);
 		}
 
+		min_ibs = max_ibs = dn->dn_indblkshift;
 		if (dn->dn_maxblkid > 0) {
 			/*
 			 * The blocksize can't change,
@@ -308,13 +309,6 @@ dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 			 */
 			ASSERT(dn->dn_datablkshift != 0);
 			min_bs = max_bs = dn->dn_datablkshift;
-			min_ibs = max_ibs = dn->dn_indblkshift;
-		} else if (dn->dn_indblkshift > max_ibs) {
-			/*
-			 * This ensures that if we reduce DN_MAX_INDBLKSHIFT,
-			 * the code will still work correctly on older pools.
-			 */
-			min_ibs = max_ibs = dn->dn_indblkshift;
 		}
 
 		/*
@@ -446,6 +440,7 @@ dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 	dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 	spa_t *spa = txh->txh_tx->tx_pool->dp_spa;
 	int epbs;
+	uint64_t l0span = 0, nl1blks = 0;
 
 	if (dn->dn_nlevels == 0)
 		return;
@@ -478,6 +473,7 @@ dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 			nblks = dn->dn_maxblkid - blkid;
 
 	}
+	l0span = nblks;    /* save for later use to calc level > 1 overhead */
 	if (dn->dn_nlevels == 1) {
 		int i;
 		for (i = 0; i < nblks; i++) {
@@ -490,24 +486,10 @@ dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 			}
 			unref += BP_GET_ASIZE(bp);
 		}
+		nl1blks = 1;
 		nblks = 0;
 	}
 
-	/*
-	 * Add in memory requirements of higher-level indirects.
-	 * This assumes a worst-possible scenario for dn_nlevels.
-	 */
-	{
-		uint64_t blkcnt = 1 + ((nblks >> epbs) >> epbs);
-		int level = (dn->dn_nlevels > 1) ? 2 : 1;
-
-		while (level++ < DN_MAX_LEVELS) {
-			txh->txh_memory_tohold += blkcnt << dn->dn_indblkshift;
-			blkcnt = 1 + (blkcnt >> epbs);
-		}
-		ASSERT(blkcnt <= dn->dn_nblkptr);
-	}
-
 	lastblk = blkid + nblks - 1;
 	while (nblks) {
 		dmu_buf_impl_t *dbuf;
@@ -578,11 +560,35 @@ dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 		}
 		dbuf_rele(dbuf, FTAG);
 
+		++nl1blks;
 		blkid += tochk;
 		nblks -= tochk;
 	}
 	rw_exit(&dn->dn_struct_rwlock);
 
+	/*
+	 * Add in memory requirements of higher-level indirects.
+	 * This assumes a worst-possible scenario for dn_nlevels and a
+	 * worst-possible distribution of l1-blocks over the region to free.
+	 */
+	{
+		uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs);
+		int level = 2;
+		/*
+		 * Here we don't use DN_MAX_LEVEL, but calculate it with the
+		 * given datablkshift and indblkshift. This makes the
+		 * difference between 19 and 8 on large files.
+		 */
+		int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) /
+		    (dn->dn_indblkshift - SPA_BLKPTRSHIFT);
+
+		while (level++ < maxlevel) {
+			txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1)
+			    << dn->dn_indblkshift;
+			blkcnt = 1 + (blkcnt >> epbs);
+		}
+	}
+
 	/* account for new level 1 indirect blocks that might show up */
 	if (skipped > 0) {
 		txh->txh_fudge += skipped << dn->dn_indblkshift;