readufs_lfs.c revision 1.3
1 /* from Id: readufs_lfs.c,v 1.5 2002/01/26 16:26:44 itohy Exp */ 2 3 /* 4 * FS specific support for 4.4BSD Log-structured Filesystem 5 * 6 * Written by ITOH, Yasufumi (itohy (at) netbsd.org). 7 * Public domain. 8 * 9 * Intended to be used for boot programs (first stage). 10 * DON'T ADD ANY FANCY FEATURE. THIS SHALL BE COMPACT. 11 */ 12 13 #include <sys/types.h> 14 #include <sys/param.h> 15 #include <sys/mount.h> 16 #include <ufs/ufs/dinode.h> 17 #include <ufs/lfs/lfs.h> 18 19 #include "readufs.h" 20 21 static int get_lfs_inode __P((ino_t ino, struct dinode *dibuf)); 22 23 static struct dinode ifile_dinode; 24 25 #define fsi (*ufsinfo) 26 #define fsi_lfs fsi.fs_u.u_lfs 27 28 /* 29 * Read and check superblock. 30 * If it is an LFS, save information from the superblock. 31 */ 32 int 33 try_lfs() 34 { 35 struct ufs_info *ufsinfo = &ufs_info; 36 struct dlfs sblk, sblk2; 37 struct dlfs *s = &sblk; 38 daddr_t sbpos; 39 int fsbshift; 40 41 #ifdef DEBUG_WITH_STDIO 42 printf("trying LFS\n"); 43 #endif 44 sbpos = btodb(LFS_LABELPAD); 45 46 /* read primary superblock */ 47 for (;;) { 48 #ifdef DEBUG_WITH_STDIO 49 printf("LFS: reading primary sblk at: 0x%x\n", sbpos); 50 #endif 51 RAW_READ(&sblk, sbpos, sizeof sblk); 52 53 #ifdef DEBUG_WITH_STDIO 54 printf("LFS: sblk: magic: 0x%x, version: %d\n", 55 sblk.dlfs_magic, sblk.dlfs_version); 56 #endif 57 58 if (sblk.dlfs_magic != LFS_MAGIC) 59 return 1; 60 61 #ifdef DEBUG_WITH_STDIO 62 printf("LFS: bsize %d, fsize %d, bshift %d, blktodb %d, fsbtodb %d, inopf %d, inopb %d\n", 63 sblk.dlfs_bsize, sblk.dlfs_fsize, 64 sblk.dlfs_bshift, sblk.dlfs_blktodb, sblk.dlfs_fsbtodb, 65 sblk.dlfs_inopf, sblk.dlfs_inopb); 66 #endif 67 if ((fsi_lfs.version = sblk.dlfs_version) == 1) { 68 fsbshift = 0; 69 break; 70 } else { 71 daddr_t sbpos1; 72 #if 0 73 fsbshift = sblk.dlfs_bshift - sblk.dlfs_blktodb + sblk.dlfs_fsbtodb - DEV_BSHIFT; 74 #endif 75 fsbshift = sblk.dlfs_fsbtodb; 76 sbpos1 = sblk.dlfs_sboffs[0] << fsbshift; 77 if (sbpos == sbpos1) 78 break; 79 #ifdef DEBUG_WITH_STDIO 80 printf("LFS: correcting primary sblk location\n"); 81 #endif 82 sbpos = sbpos1; 83 } 84 } 85 86 #ifdef DEBUG_WITH_STDIO 87 printf("fsbshift: %d\n", fsbshift); 88 printf("sboff[1]: %d\n", sblk.dlfs_sboffs[1]); 89 #endif 90 91 if (sblk.dlfs_sboffs[1] > 0) { 92 #ifdef DEBUG_WITH_STDIO 93 printf("LFS: reading secondary sblk at: 0x%x\n", 94 sblk.dlfs_sboffs[1] << fsbshift); 95 #endif 96 /* read secondary superblock */ 97 RAW_READ(&sblk2, sblk.dlfs_sboffs[1] << fsbshift, sizeof sblk2); 98 99 #ifdef DEBUG_WITH_STDIO 100 printf("LFS: sblk2: magic: 0x%x, version: %d\n", 101 sblk2.dlfs_magic, sblk2.dlfs_version); 102 #endif 103 104 if (sblk2.dlfs_magic == LFS_MAGIC) { 105 if (fsi_lfs.version == 1) { 106 if (sblk.dlfs_otstamp > sblk2.dlfs_otstamp) 107 s = &sblk2; 108 } else { 109 if (sblk.dlfs_serial > sblk2.dlfs_serial) 110 s = &sblk2; 111 } 112 } 113 } 114 115 /* This partition looks like an LFS. */ 116 fsi.get_inode = get_lfs_inode; 117 /* 118 * version 1: disk addr is in disk sector --- no shifting 119 * version 2: disk addr is in fragment 120 */ 121 fsi.fsbtodb = fsbshift; 122 123 /* Get information from the superblock. */ 124 fsi.bsize = s->dlfs_bsize; 125 fsi.nindir = s->dlfs_nindir; 126 fsi_lfs.idaddr = s->dlfs_idaddr; 127 #if 0 128 fsi_lfs.ibsize = (fsi_lfs.version == 1) ? s->dlfs_bsize : s->dlfs_fsize; 129 #else /* simplify calculation to reduce code size */ 130 /* use fsi.bsize (larger then needed for v2, but probably no harm) */ 131 #endif 132 133 /* 134 * version 1: number of inode per block 135 * version 2: number of inode per fragment (but in dlfs_inopb) 136 */ 137 fsi_lfs.inopb = s->dlfs_inopb; 138 139 fsi_lfs.ifpb = s->dlfs_ifpb; 140 fsi_lfs.ioffset = s->dlfs_cleansz + s->dlfs_segtabsz; 141 142 /* ifile is always used to look-up other inodes, so keep its inode. */ 143 if (get_lfs_inode(LFS_IFILE_INUM, &ifile_dinode)) 144 return 1; /* OOPS, failed to find inode of ifile! */ 145 146 fsi.fstype = UFSTYPE_LFS; 147 148 return 0; 149 } 150 151 /* 152 * Get inode from disk. 153 */ 154 static int 155 get_lfs_inode(ino, dibuf) 156 ino_t ino; 157 struct dinode *dibuf; 158 { 159 struct ufs_info *ufsinfo = &ufs_info; 160 daddr_t daddr; 161 char *buf = alloca(fsi.bsize); 162 struct dinode *di, *diend; 163 int i; 164 165 /* Get fs block which contains the specified inode. */ 166 if (ino == LFS_IFILE_INUM) 167 daddr = fsi_lfs.idaddr; 168 else { 169 #ifdef DEBUG_WITH_STDIO 170 printf("LFS: ino: %d\nifpb: %d, bsize: %d\n", 171 ino, fsi_lfs.ifpb, fsi.bsize); 172 #endif 173 ufs_read(&ifile_dinode, buf, 174 ino / fsi_lfs.ifpb + fsi_lfs.ioffset, 175 fsi.bsize); 176 i = ino % fsi_lfs.ifpb; 177 daddr = (fsi_lfs.version == 1) ? 178 ((IFILE_V1 *) buf + i)->if_daddr 179 : ((IFILE *) buf + i)->if_daddr; 180 } 181 #ifdef DEBUG_WITH_STDIO 182 printf("LFS(%d): daddr: %lld\n", ino, (long long)daddr); 183 #endif 184 185 if (daddr == LFS_UNUSED_DADDR) 186 return 1; 187 188 /* Read the inode block. */ 189 RAW_READ(buf, daddr << fsi.fsbtodb, 190 #if 0 191 fsi_lfs.ibsize 192 #else /* simplify calculation to reduce code size */ 193 fsi.bsize 194 #endif 195 ); 196 197 /* Search for the inode. */ 198 di = (struct dinode *) buf; 199 diend = di + fsi_lfs.inopb; 200 201 for ( ; di < diend; di++) 202 if (di->di_inumber == ino) 203 goto found; 204 /* not found */ 205 return 1; 206 207 found: 208 #ifdef DEBUG_WITH_STDIO 209 printf("LFS: dinode(%d): mode 0%o, nlink %d, inumber %d, size %d, uid %d, gid %d, db[0] %d\n", 210 ino, di->di_mode, di->di_nlink, di->di_inumber, 211 (int)di->di_size, di->di_uid, di->di_gid, di->di_db[0]); 212 #endif 213 214 *dibuf = *di; 215 216 return 0; 217 } 218
Indexes created Mon Sep 29 21:09:56 GMT 2025