1 files changed, 215 insertions, 7 deletions

diff --git a/usr/src/uts/common/fs/zfs/vdev_label.c b/usr/src/uts/common/fs/zfs/vdev_label.c
index 6235b06f17..b683c3694b 100644
--- a/usr/src/uts/common/fs/zfs/vdev_label.c
+++ b/usr/src/uts/common/fs/zfs/vdev_label.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2020 by Delphix. All rights reserved.
  * Copyright (c) 2017, Intel Corporation.
  * Copyright 2020 Joyent, Inc.
  */
@@ -150,6 +150,8 @@
 #include <sys/dsl_scan.h>
 #include <sys/abd.h>
 #include <sys/fs/zfs.h>
+#include <sys/byteorder.h>
+#include <sys/zfs_bootenv.h>
 
 /*
  * Basic routines to read and write from a vdev label.
@@ -940,7 +942,7 @@ vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason)
 	nvlist_t *label;
 	vdev_phys_t *vp;
 	abd_t *vp_abd;
-	abd_t *pad2;
+	abd_t *bootenv;
 	uberblock_t *ub;
 	abd_t *ub_abd;
 	zio_t *zio;
@@ -1101,8 +1103,8 @@ vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason)
 	ub->ub_txg = 0;
 
 	/* Initialize the 2nd padding area. */
-	pad2 = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
-	abd_zero(pad2, VDEV_PAD_SIZE);
+	bootenv = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
+	abd_zero(bootenv, VDEV_PAD_SIZE);
 
 	/*
 	 * Write everything in parallel.
@@ -1121,8 +1123,8 @@ retry:
 		 * Zero out the 2nd padding area where it might have
 		 * left over data from previous filesystem format.
 		 */
-		vdev_label_write(zio, vd, l, pad2,
-		    offsetof(vdev_label_t, vl_pad2),
+		vdev_label_write(zio, vd, l, bootenv,
+		    offsetof(vdev_label_t, vl_be),
 		    VDEV_PAD_SIZE, NULL, NULL, flags);
 
 		vdev_label_write(zio, vd, l, ub_abd,
@@ -1138,7 +1140,7 @@ retry:
 	}
 
 	nvlist_free(label);
-	abd_free(pad2);
+	abd_free(bootenv);
 	abd_free(ub_abd);
 	abd_free(vp_abd);
 
@@ -1162,6 +1164,212 @@ retry:
 }
 
 /*
+ * Done callback for vdev_label_read_bootenv_impl. If this is the first
+ * callback to finish, store our abd in the callback pointer. Otherwise, we
+ * just free our abd and return.
+ */
+static void
+vdev_label_read_bootenv_done(zio_t *zio)
+{
+	zio_t *rio = zio->io_private;
+	abd_t **cbp = rio->io_private;
+
+	ASSERT3U(zio->io_size, ==, VDEV_PAD_SIZE);
+
+	if (zio->io_error == 0) {
+		mutex_enter(&rio->io_lock);
+		if (*cbp == NULL) {
+			/* Will free this buffer in vdev_label_read_bootenv. */
+			*cbp = zio->io_abd;
+		} else {
+			abd_free(zio->io_abd);
+		}
+		mutex_exit(&rio->io_lock);
+	} else {
+		abd_free(zio->io_abd);
+	}
+}
+
+static void
+vdev_label_read_bootenv_impl(zio_t *zio, vdev_t *vd, int flags)
+{
+	for (int c = 0; c < vd->vdev_children; c++)
+		vdev_label_read_bootenv_impl(zio, vd->vdev_child[c], flags);
+
+	/*
+	 * We just use the first label that has a correct checksum; the
+	 * bootloader should have rewritten them all to be the same on boot,
+	 * and any changes we made since boot have been the same across all
+	 * labels.
+	 */
+	if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) {
+		for (int l = 0; l < VDEV_LABELS; l++) {
+			vdev_label_read(zio, vd, l,
+			    abd_alloc_linear(VDEV_PAD_SIZE, B_FALSE),
+			    offsetof(vdev_label_t, vl_be), VDEV_PAD_SIZE,
+			    vdev_label_read_bootenv_done, zio, flags);
+		}
+	}
+}
+
+int
+vdev_label_read_bootenv(vdev_t *rvd, nvlist_t *bootenv)
+{
+	nvlist_t *config;
+	spa_t *spa = rvd->vdev_spa;
+	abd_t *abd = NULL;
+	int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL |
+	    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_TRYHARD;
+
+	ASSERT(bootenv);
+	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
+
+	zio_t *zio = zio_root(spa, NULL, &abd, flags);
+	vdev_label_read_bootenv_impl(zio, rvd, flags);
+	int err = zio_wait(zio);
+
+	if (abd != NULL) {
+		char *buf;
+		vdev_boot_envblock_t *vbe = abd_to_buf(abd);
+
+		vbe->vbe_version = ntohll(vbe->vbe_version);
+		switch (vbe->vbe_version) {
+		case VB_RAW:
+			/*
+			 * if we have textual data in vbe_bootenv, create nvlist
+			 * with key "envmap".
+			 */
+			fnvlist_add_uint64(bootenv, BOOTENV_VERSION, VB_RAW);
+			vbe->vbe_bootenv[sizeof (vbe->vbe_bootenv) - 1] = '\0';
+			fnvlist_add_string(bootenv, GRUB_ENVMAP,
+			    vbe->vbe_bootenv);
+			break;
+
+		case VB_NVLIST:
+			err = nvlist_unpack(vbe->vbe_bootenv,
+			    sizeof (vbe->vbe_bootenv), &config, 0);
+			if (err == 0) {
+				fnvlist_merge(bootenv, config);
+				nvlist_free(config);
+				break;
+			}
+			/* FALLTHROUGH */
+		default:
+			/* Check for FreeBSD zfs bootonce command string */
+			buf = abd_to_buf(abd);
+			if (*buf == '\0') {
+				fnvlist_add_uint64(bootenv, BOOTENV_VERSION,
+				    VB_NVLIST);
+				break;
+			}
+			fnvlist_add_string(bootenv, FREEBSD_BOOTONCE, buf);
+		}
+
+		/*
+		 * abd was allocated in vdev_label_read_bootenv_impl()
+		 */
+		abd_free(abd);
+		/*
+		 * If we managed to read any successfully,
+		 * return success.
+		 */
+		return (0);
+	}
+	return (err);
+}
+
+int
+vdev_label_write_bootenv(vdev_t *vd, nvlist_t *env)
+{
+	zio_t *zio;
+	spa_t *spa = vd->vdev_spa;
+	vdev_boot_envblock_t *bootenv;
+	int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL;
+	int error;
+	size_t nvsize;
+	char *nvbuf;
+
+	error = nvlist_size(env, &nvsize, NV_ENCODE_XDR);
+	if (error != 0)
+		return (SET_ERROR(error));
+
+	if (nvsize >= sizeof (bootenv->vbe_bootenv)) {
+		return (SET_ERROR(E2BIG));
+	}
+
+	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
+
+	error = ENXIO;
+	for (int c = 0; c < vd->vdev_children; c++) {
+		int child_err;
+
+		child_err = vdev_label_write_bootenv(vd->vdev_child[c], env);
+		/*
+		 * As long as any of the disks managed to write all of their
+		 * labels successfully, return success.
+		 */
+		if (child_err == 0)
+			error = child_err;
+	}
+
+	if (!vd->vdev_ops->vdev_op_leaf || vdev_is_dead(vd) ||
+	    !vdev_writeable(vd)) {
+		return (error);
+	}
+	ASSERT3U(sizeof (*bootenv), ==, VDEV_PAD_SIZE);
+	abd_t *abd = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
+	abd_zero(abd, VDEV_PAD_SIZE);
+
+	bootenv = abd_borrow_buf_copy(abd, VDEV_PAD_SIZE);
+	nvbuf = bootenv->vbe_bootenv;
+	nvsize = sizeof (bootenv->vbe_bootenv);
+
+	bootenv->vbe_version = fnvlist_lookup_uint64(env, BOOTENV_VERSION);
+	switch (bootenv->vbe_version) {
+	case VB_RAW:
+		if (nvlist_lookup_string(env, GRUB_ENVMAP, &nvbuf) == 0) {
+			(void) strlcpy(bootenv->vbe_bootenv, nvbuf, nvsize);
+		}
+		error = 0;
+		break;
+
+	case VB_NVLIST:
+		error = nvlist_pack(env, &nvbuf, &nvsize, NV_ENCODE_XDR,
+		    KM_SLEEP);
+		break;
+
+	default:
+		error = EINVAL;
+		break;
+	}
+
+	if (error == 0) {
+		bootenv->vbe_version = htonll(bootenv->vbe_version);
+		abd_return_buf_copy(abd, bootenv, VDEV_PAD_SIZE);
+	} else {
+		abd_free(abd);
+		return (SET_ERROR(error));
+	}
+
+retry:
+	zio = zio_root(spa, NULL, NULL, flags);
+	for (int l = 0; l < VDEV_LABELS; l++) {
+		vdev_label_write(zio, vd, l, abd,
+		    offsetof(vdev_label_t, vl_be),
+		    VDEV_PAD_SIZE, NULL, NULL, flags);
+	}
+
+	error = zio_wait(zio);
+	if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) {
+		flags |= ZIO_FLAG_TRYHARD;
+		goto retry;
+	}
+
+	abd_free(abd);
+	return (error);
+}
+
+/*
  * ==========================================================================
  * uberblock load/sync
  * ==========================================================================