xref: /titanic_52/usr/src/grub/grub-0.97/stage2/fsys_ufs.c (revision 1b8adde7ba7d5e04395c141c5400dc2cffd7d809)
1 /*
2  *  GRUB  --  GRand Unified Bootloader
3  *  Copyright (C) 2006 Free Software Foundation, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  */
19 /*
20  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
21  * Use is subject to license terms.
22  */
23 
24 /* From Solaris usr/src/stand/lib/fs/ufs/ufsops.c */
25 
26 #ifdef	FSYS_UFS
27 
28 #include "shared.h"
29 #include "filesys.h"
30 
31 #include "ufs.h"
32 
33 /* These are the pools of buffers, etc. */
34 
35 #define SUPERBLOCK ((struct fs *)(FSYS_BUF + 0x2000))
36 #define	INODE ((struct icommon *)(FSYS_BUF + 0x1000))
37 #define DIRENT (FSYS_BUF + 0x4000)
38 #define INDIRBLK1 ((grub_daddr32_t *)(FSYS_BUF + 0x4000)) /* 2+ indir blk */
39 #define	INDIRBLK0 ((grub_daddr32_t *)(FSYS_BUF+ 0x6000))  /* 1st indirect blk */
40 
41 static int indirblk0, indirblk1;
42 
43 static int openi(grub_ino_t);
44 static grub_ino_t dlook(grub_ino_t, char *);
45 static grub_daddr32_t sbmap(grub_daddr32_t);
46 
47 /* read superblock and check fs magic */
48 int
49 ufs_mount(void)
50 {
51 	if (! IS_PC_SLICE_TYPE_SOLARIS(current_slice) ||
52 	    !devread(UFS_SBLOCK, 0, UFS_SBSIZE, (char *)SUPERBLOCK) ||
53 	    SUPERBLOCK->fs_magic != UFS_MAGIC)
54 		return 0;
55 
56 	return 1;
57 }
58 
59 
60 /*
61  * searching for a file, if successful, inode will be loaded in INODE
62  * The entry point should really be named ufs_open(char *pathname).
63  * For now, keep it consistent with the rest of fsys modules.
64  */
65 int
66 ufs_dir(char *dirname)
67 {
68 	grub_ino_t inode = ROOTINO;	/* start from root */
69 	char *fname, ch;
70 
71 	indirblk0 = indirblk1 = 0;
72 
73 	/* skip leading slashes */
74 	while (*dirname == '/')
75 		dirname++;
76 
77 	while (inode && *dirname && !isspace(*dirname)) {
78 		if (!openi(inode))
79 			return 0;
80 
81 		/* parse for next path component */
82 		fname = dirname;
83 		while (*dirname && !isspace(*dirname) && *dirname != '/')
84 			dirname++;
85 		ch = *dirname;
86 		*dirname = 0;	/* ensure null termination */
87 
88 		inode = dlook(inode, fname);
89 		*dirname = ch;
90 		while (*dirname == '/')
91 			dirname++;
92 	}
93 
94 	/* return 1 only if inode exists and is a regular file */
95 	if  (! openi(inode))
96 		return (0);
97 	filepos = 0;
98 	filemax = INODE->ic_sizelo;
99 	return (inode && ((INODE->ic_smode & IFMT) == IFREG));
100 }
101 
102 /*
103  * This is the high-level read function.
104  */
105 int
106 ufs_read(char *buf, int len)
107 {
108   	int off, size, ret = 0, ok;
109 	grub_daddr32_t lblk, dblk;
110 
111   	while (len) {
112 	  	off = blkoff(SUPERBLOCK, filepos);
113 		lblk = lblkno(SUPERBLOCK, filepos);
114 		size = SUPERBLOCK->fs_bsize;
115 		size -= off;
116 		if (size > len)
117 		  	size = len;
118 
119 		if ((dblk = sbmap(lblk)) <= 0) {
120 			/* we are in a file hole, just zero the buf */
121 			grub_memset(buf, 0, size);
122 		} else {
123 			disk_read_func = disk_read_hook;
124 			ok = devread(fsbtodb(SUPERBLOCK, dblk), off, size, buf);
125 			disk_read_func = 0;
126 			if (!ok)
127 		  		return 0;
128 		}
129 		buf += size;
130 		len -= size;
131 		filepos += size;
132 		ret += size;
133 	}
134 
135 	return (ret);
136 }
137 
138 int
139 ufs_embed (int *start_sector, int needed_sectors)
140 {
141 	if (needed_sectors > 14)
142         	return 0;
143 
144 	*start_sector = 2;
145 	return 1;
146 }
147 
148 /* read inode and place content in INODE */
149 static int
150 openi(grub_ino_t inode)
151 {
152 	grub_daddr32_t dblk;
153 	int off;
154 
155 	/* get block and byte offset into the block */
156 	dblk = fsbtodb(SUPERBLOCK, itod(SUPERBLOCK, inode));
157 	off = itoo(SUPERBLOCK, inode) * sizeof (struct icommon);
158 
159 	return (devread(dblk, off, sizeof (struct icommon), (char *)INODE));
160 }
161 
162 /*
163  * Performs fileblock mapping. Convert file block no. to disk block no.
164  * Returns 0 when block doesn't exist and <0 when block isn't initialized
165  * (i.e belongs to a hole in the file).
166  */
167 grub_daddr32_t
168 sbmap(grub_daddr32_t bn)
169 {
170   	int level, bound, i, index;
171 	grub_daddr32_t nb, blkno;
172 	grub_daddr32_t *db = INODE->ic_db;
173 
174 	/* blocks 0..UFS_NDADDR are direct blocks */
175 	if (bn < UFS_NDADDR) {
176 		return db[bn];
177 	}
178 
179 	/* determine how many levels of indirection. */
180 	level = 0;
181 	bn -= UFS_NDADDR;
182 	bound = UFS_NINDIR(SUPERBLOCK);
183 	while (bn >= bound) {
184 		level++;
185 		bn -= bound;
186 		bound *= UFS_NINDIR(SUPERBLOCK);
187 	}
188 	if (level >= UFS_NIADDR)	/* bn too big */
189 		return ((grub_daddr32_t)0);
190 
191 	/* fetch the first indirect block */
192 	nb = INODE->ic_ib[level];
193 	if (nb == 0) {
194 		return ((grub_daddr32_t)0);
195 	}
196 	if (indirblk0 != nb) {
197 		indirblk0 = 0;
198 		blkno = fsbtodb(SUPERBLOCK, nb);
199 		if (!devread(blkno, 0, SUPERBLOCK->fs_bsize,
200 		    (char *)INDIRBLK0))
201 			return (0);
202 		indirblk0 = nb;
203 	}
204 	bound /= UFS_NINDIR(SUPERBLOCK);
205 	index = (bn / bound) % UFS_NINDIR(SUPERBLOCK);
206 	nb = INDIRBLK0[index];
207 
208 	/* fetch through the indirect blocks */
209 	for (i = 1; i <= level; i++) {
210 		if (indirblk1 != nb) {
211 			blkno = fsbtodb(SUPERBLOCK, nb);
212 			if (!devread(blkno, 0, SUPERBLOCK->fs_bsize,
213 			    (char *)INDIRBLK1))
214 				return (0);
215 			indirblk1 = nb;
216 		}
217 		bound /= UFS_NINDIR(SUPERBLOCK);
218 		index = (bn / bound) % UFS_NINDIR(SUPERBLOCK);
219 		nb = INDIRBLK1[index];
220 		if (nb == 0)
221 			return ((grub_daddr32_t)0);
222 	}
223 
224 	return (nb);
225 }
226 
227 /* search directory content for name, return inode number */
228 static grub_ino_t
229 dlook(grub_ino_t dir_ino, char *name)
230 {
231 	int loc, off;
232 	grub_daddr32_t lbn, dbn, dblk;
233 	struct direct *dp;
234 
235 	if ((INODE->ic_smode & IFMT) != IFDIR)
236 		return 0;
237 
238 	loc = 0;
239 	while (loc < INODE->ic_sizelo) {
240 	  	/* offset into block */
241 		off = blkoff(SUPERBLOCK, loc);
242 		if (off == 0) {		/* need to read in a new block */
243 
244 		  	/* get logical block number */
245 			lbn = lblkno(SUPERBLOCK, loc);
246 			/* resolve indrect blocks */
247 			dbn = sbmap(lbn);
248 			if (dbn == 0)
249 				return (0);
250 
251 			dblk = fsbtodb(SUPERBLOCK, dbn);
252 			if (!devread(dblk, 0, SUPERBLOCK->fs_bsize,
253 			    (char *)DIRENT)) {
254 				return 0;
255 			}
256 		}
257 
258 		dp = (struct direct *)(DIRENT + off);
259 		if (dp->d_ino && substring(name, dp->d_name) == 0)
260 			return (dp->d_ino);
261 		loc += dp->d_reclen;
262 	}
263 	return (0);
264 }
265 
266 #endif /* FSYS_UFS */
267