MFC r264077:

Add BIO_DELETE support to ZVOL.

It is an adapted merge from the vendor branch of:
    701 UNMAP support for COMSTAR  (in part related to ZFS)
    2130 zvol DKIOCFREE uses nested DMU transactions

1 files changed, 70 insertions, 4 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
index 5e50f3f..a6351da 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
@@ -25,9 +25,12 @@
  * All rights reserved.
  * Copyright (c) 2013 by Delphix. All rights reserved.
  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
+ *
+ * Portions Copyright 2010 Robert Milkowski
+ *
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  */
 
-/* Portions Copyright 2010 Robert Milkowski */
 /* Portions Copyright 2011 Martin Matuska <mm@FreeBSD.org> */
 
 /*
@@ -153,6 +156,8 @@ int zvol_maxphys = DMU_MAX_ACCESS/2;
 
 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
     nvlist_t *, nvlist_t *);
+static void zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off,
+    uint64_t len, boolean_t sync);
 static int zvol_remove_zv(zvol_state_t *);
 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
 static int zvol_dumpify(zvol_state_t *zv);
@@ -386,6 +391,24 @@ zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
 }
 
 /*
+ * Replay a TX_TRUNCATE ZIL transaction if asked.  TX_TRUNCATE is how we
+ * implement DKIOCFREE/free-long-range.
+ */
+static int
+zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
+{
+	uint64_t offset, length;
+
+	if (byteswap)
+		byteswap_uint64_array(lr, sizeof (*lr));
+
+	offset = lr->lr_offset;
+	length = lr->lr_length;
+
+	return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
+}
+
+/*
  * Replay a TX_WRITE ZIL transaction that didn't get committed
  * after a system failure
  */
@@ -435,7 +458,7 @@ zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
 
 /*
  * Callback vectors for replaying records.
- * Only TX_WRITE is needed for zvol.
+ * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
  */
 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
 	zvol_replay_err,	/* 0 no such transaction type */
@@ -448,7 +471,7 @@ zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
 	zvol_replay_err,	/* TX_LINK */
 	zvol_replay_err,	/* TX_RENAME */
 	zvol_replay_write,	/* TX_WRITE */
-	zvol_replay_err,	/* TX_TRUNCATE */
+	zvol_replay_truncate,	/* TX_TRUNCATE */
 	zvol_replay_err,	/* TX_SETATTR */
 	zvol_replay_err,	/* TX_ACL */
 	zvol_replay_err,	/* TX_CREATE_ACL */
@@ -1316,6 +1339,21 @@ zvol_strategy(struct bio *bp)
 	rl = zfs_range_lock(&zv->zv_znode, off, resid,
 	    doread ? RL_READER : RL_WRITER);
 
+	if (bp->bio_cmd == BIO_DELETE) {
+		dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
+		error = dmu_tx_assign(tx, TXG_WAIT);
+		if (error != 0) {
+			dmu_tx_abort(tx);
+		} else {
+			zvol_log_truncate(zv, tx, off, resid, B_TRUE);
+			dmu_tx_commit(tx);
+			error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
+			    off, resid);
+			resid = 0;
+		}
+		goto unlock;
+	}
+
 	while (resid != 0 && off < volsize) {
 		size_t size = MIN(resid, zvol_maxphys);
 #ifdef illumos
@@ -1351,6 +1389,7 @@ zvol_strategy(struct bio *bp)
 		addr += size;
 		resid -= size;
 	}
+unlock:
 	zfs_range_unlock(rl);
 
 	bp->bio_completed = bp->bio_length - resid;
@@ -1648,9 +1687,36 @@ zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
 /*
  * END entry points to allow external callers access to the volume.
  */
+#endif	/* sun */
 
 /*
+ * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
+ */
+static void
+zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
+    boolean_t sync)
+{
+	itx_t *itx;
+	lr_truncate_t *lr;
+	zilog_t *zilog = zv->zv_zilog;
+
+	if (zil_replaying(zilog, tx))
+		return;
+
+	itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
+	lr = (lr_truncate_t *)&itx->itx_lr;
+	lr->lr_foid = ZVOL_OBJ;
+	lr->lr_offset = off;
+	lr->lr_length = len;
+
+	itx->itx_sync = sync;
+	zil_itx_assign(zilog, itx, tx);
+}
+
+#ifdef sun
+/*
  * Dirtbag ioctls to support mkfs(1M) for UFS filesystems.  See dkio(7I).
+ * Also a dirtbag dkio ioctl for unmap/free-block functionality.
  */
 /*ARGSUSED*/
 int
@@ -2271,12 +2337,12 @@ zvol_geom_start(struct bio *bp)
 		break;
 	case BIO_READ:
 	case BIO_WRITE:
+	case BIO_DELETE:
 		if (!THREAD_CAN_SLEEP())
 			goto enqueue;
 		zvol_strategy(bp);
 		break;
 	case BIO_GETATTR:
-	case BIO_DELETE:
 	default:
 		g_io_deliver(bp, EOPNOTSUPP);
 		break;