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      1 /*	$NetBSD: v7fs_superblock.c,v 1.2 2011/07/18 21:51:49 apb Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by UCHIYAMA Yasushi.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #if HAVE_NBTOOL_CONFIG_H
     33 #include "nbtool_config.h"
     34 #endif
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: v7fs_superblock.c,v 1.2 2011/07/18 21:51:49 apb Exp $");
     38 #if defined _KERNEL_OPT
     39 #include "opt_v7fs.h"
     40 #endif
     41 
     42 #ifdef _KERNEL
     43 #include <sys/systm.h>
     44 #include <sys/param.h>	/* errno */
     45 #else
     46 #include <stdio.h>
     47 #include <string.h>
     48 #include <errno.h>
     49 #endif
     50 
     51 #include "v7fs.h"
     52 #include "v7fs_impl.h"
     53 #include "v7fs_endian.h"
     54 #include "v7fs_superblock.h"
     55 #include "v7fs_inode.h"
     56 #include "v7fs_datablock.h"
     57 
     58 #ifdef V7FS_SUPERBLOCK_DEBUG
     59 #define	DPRINTF(fmt, args...)	printf("%s: " fmt, __func__, ##args)
     60 #define	DPRINTF_(fmt, args...)	printf(fmt, ##args)
     61 #else
     62 #define	DPRINTF(fmt, args...)	((void)0)
     63 #define	DPRINTF_(fmt, args...)	((void)0)
     64 #endif
     65 
     66 static void v7fs_superblock_endian_convert(struct v7fs_self *,
     67     struct v7fs_superblock *, struct v7fs_superblock *);
     68 static int v7fs_superblock_sanity(struct v7fs_self *);
     69 
     70 /* Load superblock from disk. */
     71 int
     72 v7fs_superblock_load(struct v7fs_self *fs)
     73 {
     74 	struct v7fs_superblock *disksb;
     75 	void *buf;
     76 	int error;
     77 
     78 	if (!(buf = scratch_read(fs, V7FS_SUPERBLOCK_SECTOR)))
     79 		return EIO;
     80 	disksb = (struct v7fs_superblock *)buf;
     81 	v7fs_superblock_endian_convert(fs, &fs->superblock, disksb);
     82 	scratch_free(fs, buf);
     83 
     84 	if ((error = v7fs_superblock_sanity(fs)))
     85 		return error;
     86 
     87 	return 0;
     88 }
     89 
     90 /* Writeback superblock to disk. */
     91 int
     92 v7fs_superblock_writeback(struct v7fs_self *fs)
     93 {
     94 	struct v7fs_superblock *memsb = &fs->superblock;
     95 	struct v7fs_superblock *disksb;
     96 	void *buf;
     97 	int error = 0;
     98 
     99 	if (!memsb->modified)
    100 		return 0;
    101 
    102 	if (!(buf = scratch_read(fs, V7FS_SUPERBLOCK_SECTOR)))
    103 		return EIO;
    104 	disksb = (struct v7fs_superblock *)buf;
    105 	v7fs_superblock_endian_convert(fs, disksb, memsb);
    106 	if (!fs->io.write(fs->io.cookie, buf, V7FS_SUPERBLOCK_SECTOR))
    107 		error = EIO;
    108 	scratch_free(fs, buf);
    109 
    110 	memsb->modified = 0;
    111 	DPRINTF("done. %d\n", error);
    112 
    113 	return error;
    114 }
    115 
    116 /* Check endian mismatch. */
    117 static int
    118 v7fs_superblock_sanity(struct v7fs_self *fs)
    119 {
    120 	const struct v7fs_superblock *sb = &fs->superblock;
    121 	void *buf = 0;
    122 
    123 	if ((sb->volume_size < 128) || /* smaller than 64KB. */
    124 	    (sb->datablock_start_sector > sb->volume_size) ||
    125 	    (sb->nfreeinode > V7FS_MAX_FREEINODE) ||
    126 	    (sb->nfreeblock > V7FS_MAX_FREEBLOCK) ||
    127 	    (sb->update_time < 0) ||
    128 	    (sb->total_freeblock > sb->volume_size) ||
    129 	    ((sb->nfreeinode == 0) && (sb->nfreeblock == 0) &&
    130 		(sb->total_freeblock == 0) && (sb->total_freeinode == 0)) ||
    131 	    (!(buf = scratch_read(fs, sb->volume_size - 1)))) {
    132 		DPRINTF("invalid super block.\n");
    133 		return EINVAL;
    134 	}
    135 	if (buf)
    136 		scratch_free(fs, buf);
    137 
    138 	return 0;
    139 }
    140 
    141 /* Fill free block to superblock cache. */
    142 int
    143 v7fs_freeblock_update(struct v7fs_self *fs, v7fs_daddr_t blk)
    144 {
    145 	/* Assume superblock is locked by caller. */
    146 	struct v7fs_superblock *sb = &fs->superblock;
    147 	struct v7fs_freeblock *fb;
    148 	void *buf;
    149 	int error;
    150 
    151 	/* Read next freeblock table from disk. */
    152 	if (!datablock_number_sanity(fs, blk) || !(buf = scratch_read(fs, blk)))
    153 		return EIO;
    154 
    155 	/* Update in-core superblock freelist. */
    156 	fb = (struct v7fs_freeblock *)buf;
    157 	if ((error = v7fs_freeblock_endian_convert(fs, fb))) {
    158 		scratch_free(fs, buf);
    159 		return error;
    160 	}
    161 	DPRINTF("freeblock table#%d, nfree=%d\n", blk, fb->nfreeblock);
    162 
    163 	memcpy(sb->freeblock, fb->freeblock, sizeof(blk) * fb->nfreeblock);
    164 	sb->nfreeblock = fb->nfreeblock;
    165 	sb->modified = true;
    166 	scratch_free(fs, buf);
    167 
    168 	return 0;
    169 }
    170 
    171 int
    172 v7fs_freeblock_endian_convert(struct v7fs_self *fs __unused,
    173     struct v7fs_freeblock *fb __unused)
    174 {
    175 #ifdef V7FS_EI
    176 	int i;
    177 	int16_t nfree;
    178 
    179 	nfree = V7FS_VAL16(fs, fb->nfreeblock);
    180 	if (nfree <= 0 || nfree > V7FS_MAX_FREEBLOCK) {
    181 		DPRINTF("invalid freeblock list. %d (max=%d)\n", nfree,
    182 		    V7FS_MAX_FREEBLOCK);
    183 		return ENOSPC;
    184 	}
    185 	fb->nfreeblock = nfree;
    186 
    187 	for (i = 0; i < nfree; i++) {
    188 		fb->freeblock[i] = V7FS_VAL32(fs, fb->freeblock[i]);
    189 	}
    190 #endif /* V7FS_EI */
    191 
    192 	return 0;
    193 }
    194 
    195 /* Fill free inode to superblock cache. */
    196 int
    197 v7fs_freeinode_update(struct v7fs_self *fs)
    198 {
    199 	/* Assume superblock is locked by caller. */
    200 	struct v7fs_superblock *sb = &fs->superblock;
    201 	v7fs_ino_t *freeinode = sb->freeinode;
    202 	size_t i, j, k;
    203 	v7fs_ino_t ino;
    204 
    205 	/* Loop over all inode list. */
    206 	for (i = V7FS_ILIST_SECTOR, ino = 1/* inode start from 1*/, k = 0;
    207 	    i < sb->datablock_start_sector; i++) {
    208 		struct v7fs_inode_diskimage *di;
    209 		void *buf;
    210 		if (!(buf = scratch_read(fs, i))) {
    211 			DPRINTF("block %zu I/O error.\n", i);
    212 			ino += V7FS_INODE_PER_BLOCK;
    213 			continue;
    214 		}
    215 		di = (struct v7fs_inode_diskimage *)buf;
    216 
    217 		for (j = 0;
    218 		    (j < V7FS_INODE_PER_BLOCK) && (k < V7FS_MAX_FREEINODE);
    219 		    j++, di++, ino++) {
    220 			if (v7fs_inode_allocated(di))
    221 				continue;
    222 			DPRINTF("free inode%d\n", ino);
    223 			freeinode[k++] = ino;
    224 		}
    225 		scratch_free(fs, buf);
    226 	}
    227 	sb->nfreeinode = k;
    228 
    229 	return 0;
    230 }
    231 
    232 static void
    233 v7fs_superblock_endian_convert(struct v7fs_self *fs __unused,
    234     struct v7fs_superblock *to,  struct v7fs_superblock *from)
    235 {
    236 #ifdef V7FS_EI
    237 #define	conv16(m)	(to->m = V7FS_VAL16(fs, from->m))
    238 #define	conv32(m)	(to->m = V7FS_VAL32(fs, from->m))
    239 	int i;
    240 
    241 	conv16(datablock_start_sector);
    242 	conv32(volume_size);
    243 	conv16(nfreeblock);
    244 	v7fs_daddr_t *dfrom = from->freeblock;
    245 	v7fs_daddr_t *dto = to->freeblock;
    246 	for (i = 0; i < V7FS_MAX_FREEBLOCK; i++, dfrom++, dto++)
    247 		*dto = V7FS_VAL32(fs, *dfrom);
    248 
    249 	conv16(nfreeinode);
    250 	v7fs_ino_t *ifrom = from->freeinode;
    251 	v7fs_ino_t *ito = to->freeinode;
    252 	for (i = 0; i < V7FS_MAX_FREEINODE; i++, ifrom++, ito++)
    253 		*ito = V7FS_VAL16(fs, *ifrom);
    254 
    255 	conv32(update_time);
    256 	conv32(total_freeblock);
    257 	conv16(total_freeinode);
    258 #undef conv16
    259 #undef conv32
    260 #else /* V7FS_EI */
    261 	memcpy(to, from , sizeof(*to));
    262 #endif /* V7FS_EI */
    263 }
    264