fix some assign arc buf with brt clone and O_TRUNC

this fixes some bugs when opening a file wiht O_TRUNC and writing to the same file at the same time with `dd` for example. O_TRUNC in the VFS calls set_attr and set_attr will figure out a trunc based on the O_TRUNC flag. dmu_free_long_range_impl will free the data after that. If a reflink is and write is running at the same time it will fail with: kernel:VERIFY(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED) failed kernel:PANIC at dbuf.c:2925:dbuf_assign_arcbuf() Signed-off-by: Kay Pedersen <[email protected]>
openzfs · Aug 1, 2023 · a1a87b2 · a1a87b2
1 parent a5fdba1
commit a1a87b2
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Showing 2 changed files with 14 additions and 14 deletions.
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
@@ -915,19 +915,6 @@ dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
 		    dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
 		mutex_exit(&dp->dp_lock);
 
-		/*
-		 * To avoid filling up a TXG with just frees, wait for
-		 * the next TXG to open before freeing more chunks if
-		 * we have reached the threshold of frees.
-		 */
-		if (dirty_frees_threshold != 0 &&
-		    long_free_dirty >= dirty_frees_threshold) {
-			DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
-			dmu_tx_commit(tx);
-			txg_wait_open(dp, 0, B_TRUE);
-			continue;
-		}
-
 		/*
 		 * In order to prevent unnecessary write throttling, for each
 		 * TXG, we track the cumulative size of L1 blocks being dirtied
@@ -947,6 +934,19 @@ dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
 		    uint64_t, txg);
 		dnode_free_range(dn, chunk_begin, chunk_len, tx);
 
+		/*
+		 * To avoid filling up a TXG with just frees, wait for
+		 * the next TXG to open before freeing more chunks if
+		 * we have reached the threshold of frees.
+		 */
+		if (dirty_frees_threshold != 0 &&
+		    long_free_dirty >= dirty_frees_threshold) {
+			DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
+			dmu_tx_commit(tx);
+			txg_wait_open(dp, 0, B_TRUE);
+			continue;
+		}
+
 		dmu_tx_commit(tx);
 
 		length -= chunk_len;

diff --git a/tests/zfs-tests/cmd/clonefile.c b/tests/zfs-tests/cmd/clonefile.c
@@ -210,7 +210,7 @@ main(int argc, char **argv)
 		return (1);
 	}
 
-	int dfd = open(argv[optind+1], O_WRONLY|O_CREAT,
+	int dfd = open(argv[optind+1], O_WRONLY|O_TRUNC,
 	    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 	if (dfd < 0) {
 		fprintf(stderr, "open: %s: %s\n",