1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or https://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 #include <sys/zfs_context.h>
23 #include <sys/spa.h>
24 #include <sys/spa_impl.h>
25 #include <sys/dmu.h>
26 #include <sys/zap.h>
27 #include <sys/vdev.h>
28 #include <sys/vdev_os.h>
29 #include <sys/vdev_impl.h>
30 #include <sys/uberblock_impl.h>
31 #include <sys/metaslab.h>
32 #include <sys/metaslab_impl.h>
33 #include <sys/zio.h>
34 #include <sys/dsl_scan.h>
35 #include <sys/abd.h>
36 #include <sys/fs/zfs.h>
37 
38 int
39 vdev_label_write_pad2(vdev_t *vd, const char *buf, size_t size)
40 {
41 	spa_t *spa = vd->vdev_spa;
42 	zio_t *zio;
43 	abd_t *pad2;
44 	int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL;
45 	int error;
46 
47 	if (size > VDEV_PAD_SIZE)
48 		return (EINVAL);
49 
50 	if (!vd->vdev_ops->vdev_op_leaf)
51 		return (ENODEV);
52 	if (vdev_is_dead(vd))
53 		return (ENXIO);
54 
55 	ASSERT3U(spa_config_held(spa, SCL_ALL, RW_WRITER), ==, SCL_ALL);
56 
57 	pad2 = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
58 	abd_copy_from_buf(pad2, buf, size);
59 	abd_zero_off(pad2, size, VDEV_PAD_SIZE - size);
60 
61 retry:
62 	zio = zio_root(spa, NULL, NULL, flags);
63 	vdev_label_write(zio, vd, 0, pad2,
64 	    offsetof(vdev_label_t, vl_be),
65 	    VDEV_PAD_SIZE, NULL, NULL, flags);
66 	error = zio_wait(zio);
67 	if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) {
68 		flags |= ZIO_FLAG_TRYHARD;
69 		goto retry;
70 	}
71 
72 	abd_free(pad2);
73 	return (error);
74 }
75 
76 static void
77 vdev_child_done(zio_t *zio)
78 {
79 	zio_t *pio = zio->io_private;
80 
81 	mutex_enter(&pio->io_lock);
82 	pio->io_error = zio_worst_error(pio->io_error, zio->io_error);
83 	mutex_exit(&pio->io_lock);
84 }
85 
86 /*
87  * Check if the reserved boot area is in-use.
88  *
89  * When booting FreeBSD with an MBR partition with ZFS, the zfsboot file
90  * (which understands the ZFS file system) is written to the ZFS BOOT
91  * reserve area (at offset 512K). We check for that here before attaching
92  * a disk to raidz which would then corrupt this boot data.
93  */
94 int
95 vdev_check_boot_reserve(spa_t *spa, vdev_t *childvd)
96 {
97 	ASSERT(childvd->vdev_ops->vdev_op_leaf);
98 
99 	size_t size = SPA_MINBLOCKSIZE;
100 	abd_t *abd = abd_alloc_linear(size, B_FALSE);
101 
102 	zio_t *pio = zio_root(spa, NULL, NULL, 0);
103 	/*
104 	 * Note: zio_vdev_child_io() adds VDEV_LABEL_START_SIZE to the offset
105 	 * to calculate the physical offset to write to.  Passing in a negative
106 	 * offset lets us access the boot area.
107 	 */
108 	zio_nowait(zio_vdev_child_io(pio, NULL, childvd,
109 	    VDEV_BOOT_OFFSET - VDEV_LABEL_START_SIZE, abd, size, ZIO_TYPE_READ,
110 	    ZIO_PRIORITY_ASYNC_READ, 0, vdev_child_done, pio));
111 	zio_wait(pio);
112 
113 	unsigned char *buf = abd_to_buf(abd);
114 
115 	/*
116 	 * The BTX server has a special header at the begining.
117 	 *
118 	 * btx_hdr:	.byte 0xeb		# Machine ID
119 	 *		.byte 0xe		# Header size
120 	 *		.ascii "BTX"		# Magic
121 	 *		.byte 0x1		# Major version
122 	 *		.byte 0x2		# Minor version
123 	 *		.byte BTX_FLAGS		# Flags
124 	 */
125 	if (buf[0] == 0xeb && buf[1] == 0x0e &&
126 	    buf[2] == 'B' && buf[3] == 'T' && buf[4] == 'X') {
127 		abd_free(abd);
128 		return (EBUSY);
129 	}
130 
131 	abd_free(abd);
132 	return (0);
133 }
134