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hammer2.c revision 1.3
      1 /*        $NetBSD: hammer2.c,v 1.3 2020/01/04 03:43:18 tkusumi Exp $      */
      2 
      3 /*-
      4  * Copyright (c) 2017-2019 The DragonFly Project
      5  * Copyright (c) 2017-2019 Tomohiro Kusumi <tkusumi (at) netbsd.org>
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
     18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
     21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     27  * SUCH DAMAGE.
     28  */
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: hammer2.c,v 1.3 2020/01/04 03:43:18 tkusumi Exp $");
     31 
     32 #include <stdio.h>
     33 #include <stdlib.h>
     34 #include <stdbool.h>
     35 #include <string.h>
     36 #include <err.h>
     37 #include <assert.h>
     38 
     39 #include "fstyp.h"
     40 #include "hammer2_disk.h"
     41 
     42 static hammer2_volume_data_t*
     43 read_voldata(FILE *fp)
     44 {
     45 	hammer2_volume_data_t *voldata;
     46 
     47 	voldata = read_buf(fp, 0, sizeof(*voldata));
     48 	if (voldata == NULL)
     49 		err(1, "failed to read volume data");
     50 
     51 	return (voldata);
     52 }
     53 
     54 static int
     55 test_voldata(const hammer2_volume_data_t *voldata)
     56 {
     57 	if (voldata->magic != HAMMER2_VOLUME_ID_HBO &&
     58 	    voldata->magic != HAMMER2_VOLUME_ID_ABO)
     59 		return (1);
     60 
     61 	return (0);
     62 }
     63 
     64 static hammer2_media_data_t*
     65 read_media(FILE *fp, const hammer2_blockref_t *bref, size_t *media_bytes)
     66 {
     67 	hammer2_media_data_t *media;
     68 	hammer2_off_t io_off, io_base;
     69 	size_t bytes, io_bytes, boff;
     70 
     71 	bytes = (bref->data_off & HAMMER2_OFF_MASK_RADIX);
     72 	if (bytes)
     73 		bytes = (size_t)1 << bytes;
     74 	*media_bytes = bytes;
     75 
     76 	if (!bytes) {
     77 		warnx("blockref has no data");
     78 		return (NULL);
     79 	}
     80 
     81 	io_off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
     82 	io_base = io_off & ~(hammer2_off_t)(HAMMER2_MINIOSIZE - 1);
     83 	boff = (size_t)(io_off - io_base);
     84 
     85 	io_bytes = HAMMER2_MINIOSIZE;
     86 	while (io_bytes + boff < bytes)
     87 		io_bytes <<= 1;
     88 
     89 	if (io_bytes > sizeof(hammer2_media_data_t)) {
     90 		warnx("invalid I/O bytes");
     91 		return (NULL);
     92 	}
     93 
     94 	if (fseek(fp, (long int)io_base, SEEK_SET) == -1) {
     95 		warnx("failed to seek media");
     96 		return (NULL);
     97 	}
     98 	media = read_buf(fp, (off_t)io_base, io_bytes);
     99 	if (media == NULL) {
    100 		warnx("failed to read media");
    101 		return (NULL);
    102 	}
    103 	if (boff)
    104 		memcpy(media, (char *)media + boff, bytes);
    105 
    106 	return (media);
    107 }
    108 
    109 static int
    110 find_pfs(FILE *fp, const hammer2_blockref_t *bref, const char *pfs, bool *res)
    111 {
    112 	hammer2_media_data_t *media;
    113 	hammer2_inode_data_t ipdata;
    114 	hammer2_blockref_t *bscan;
    115 	size_t bytes;
    116 	int i, bcount;
    117 
    118 	media = read_media(fp, bref, &bytes);
    119 	if (media == NULL)
    120 		return (-1);
    121 
    122 	switch (bref->type) {
    123 	case HAMMER2_BREF_TYPE_INODE:
    124 		ipdata = media->ipdata;
    125 		if (ipdata.meta.pfs_type & HAMMER2_PFSTYPE_SUPROOT) {
    126 			bscan = &ipdata.u.blockset.blockref[0];
    127 			bcount = HAMMER2_SET_COUNT;
    128 		} else {
    129 			bscan = NULL;
    130 			bcount = 0;
    131 			if (ipdata.meta.op_flags & HAMMER2_OPFLAG_PFSROOT) {
    132 				if (memchr(ipdata.filename, 0,
    133 				    sizeof(ipdata.filename))) {
    134 					if (!strcmp(
    135 					    (const char*)ipdata.filename, pfs))
    136 						*res = true;
    137 				} else {
    138 					if (strlen(pfs) > 0 &&
    139 					    !memcmp(ipdata.filename, pfs,
    140 					    strlen(pfs)))
    141 						*res = true;
    142 				}
    143 			} else
    144 				assert(0);
    145 		}
    146 		break;
    147 	case HAMMER2_BREF_TYPE_INDIRECT:
    148 		bscan = &media->npdata[0];
    149 		bcount = (int)(bytes / sizeof(hammer2_blockref_t));
    150 		break;
    151 	default:
    152 		bscan = NULL;
    153 		bcount = 0;
    154 		break;
    155 	}
    156 
    157 	for (i = 0; i < bcount; ++i) {
    158 		if (bscan[i].type != HAMMER2_BREF_TYPE_EMPTY) {
    159 			if (find_pfs(fp, &bscan[i], pfs, res) == -1) {
    160 				free(media);
    161 				return (-1);
    162 			}
    163 		}
    164 	}
    165 	free(media);
    166 
    167 	return (0);
    168 }
    169 
    170 static char*
    171 extract_device_name(const char *devpath)
    172 {
    173 	char *p, *head;
    174 
    175 	if (!devpath)
    176 		return NULL;
    177 
    178 	p = strdup(devpath);
    179 	head = p;
    180 
    181 	p = strchr(p, '@');
    182 	if (p)
    183 		*p = 0;
    184 
    185 	p = strrchr(head, '/');
    186 	if (p) {
    187 		p++;
    188 		if (*p == 0) {
    189 			free(head);
    190 			return NULL;
    191 		}
    192 		p = strdup(p);
    193 		free(head);
    194 		return p;
    195 	}
    196 
    197 	return head;
    198 }
    199 
    200 static int
    201 read_label(FILE *fp, char *label, size_t size)
    202 {
    203 	hammer2_blockref_t broot, best, *bref;
    204 	hammer2_media_data_t *vols[HAMMER2_NUM_VOLHDRS], *media;
    205 	size_t bytes;
    206 	bool res = false;
    207 	int i, best_i, error = 1;
    208 	const char *pfs;
    209 	char *devname;
    210 
    211 	best_i = -1;
    212 	memset(&best, 0, sizeof(best));
    213 
    214 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
    215 		memset(&broot, 0, sizeof(broot));
    216 		broot.type = HAMMER2_BREF_TYPE_VOLUME;
    217 		broot.data_off = ((hammer2_off_t)i *
    218 		    (hammer2_off_t)HAMMER2_ZONE_BYTES64) | HAMMER2_PBUFRADIX;
    219 		vols[i] = read_buf(fp,
    220 		    (off_t)(broot.data_off & ~HAMMER2_OFF_MASK_RADIX),
    221 		    sizeof(*vols[i]));
    222 		broot.mirror_tid = vols[i]->voldata.mirror_tid;
    223 		if (best_i < 0 || best.mirror_tid < broot.mirror_tid) {
    224 			best_i = i;
    225 			best = broot;
    226 		}
    227 	}
    228 	if (best_i == -1) {
    229 		warnx("failed to find best zone");
    230 		goto fail;
    231 	}
    232 
    233 	bref = &vols[best_i]->voldata.sroot_blockset.blockref[0];
    234 	if (bref->type != HAMMER2_BREF_TYPE_INODE) {
    235 		warnx("blockref type is not inode");
    236 		goto fail;
    237 	}
    238 
    239 	media = read_media(fp, bref, &bytes);
    240 	if (media == NULL) {
    241 		goto fail;
    242 	}
    243 
    244 	/*
    245 	 * fstyp_function in DragonFly takes an additional devpath argument
    246 	 * which doesn't exist in FreeBSD and NetBSD.
    247 	 */
    248 #ifdef HAS_DEVPATH
    249 	pfs = strchr(devpath, '@');
    250 	if (!pfs) {
    251 		assert(strlen(devpath));
    252 		switch (devpath[strlen(devpath) - 1]) {
    253 		case 'a':
    254 			pfs = "BOOT";
    255 			break;
    256 		case 'd':
    257 			pfs = "ROOT";
    258 			break;
    259 		default:
    260 			pfs = "DATA";
    261 			break;
    262 		}
    263 	} else
    264 		pfs++;
    265 
    266 	if (strlen(pfs) > HAMMER2_INODE_MAXNAME) {
    267 		goto fail;
    268 	}
    269 	devname = extract_device_name(devpath);
    270 #else
    271 	pfs = "";
    272 	devname = extract_device_name(NULL);
    273 	assert(!devname);
    274 #endif
    275 
    276 	/* Add device name to help support multiple autofs -media mounts. */
    277 	if (find_pfs(fp, bref, pfs, &res) == 0 && res) {
    278 		if (devname)
    279 			snprintf(label, size, "%s_%s", pfs, devname);
    280 		else
    281 			strlcpy(label, pfs, size);
    282 	} else {
    283 		memset(label, 0, size);
    284 		memcpy(label, media->ipdata.filename,
    285 		    sizeof(media->ipdata.filename));
    286 		if (devname) {
    287 			strlcat(label, "_", size);
    288 			strlcat(label, devname, size);
    289 		}
    290 	}
    291 	if (devname)
    292 		free(devname);
    293 	free(media);
    294 	error = 0;
    295 fail:
    296 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++)
    297 		free(vols[i]);
    298 
    299 	return (error);
    300 }
    301 
    302 int
    303 fstyp_hammer2(FILE *fp, char *label, size_t size)
    304 {
    305 	hammer2_volume_data_t *voldata;
    306 	int error = 1;
    307 
    308 	voldata = read_voldata(fp);
    309 	if (test_voldata(voldata))
    310 		goto fail;
    311 
    312 	error = read_label(fp, label, size);
    313 fail:
    314 	free(voldata);
    315 	return (error);
    316 }
    317