xref: /freebsd/sys/fs/ext2fs/ext2_balloc.c (revision 6f1af0d7d2af54b339b5212434cd6d4fda628d80)
1 /*-
2  *  modified for Lites 1.1
3  *
4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
5  *  University of Utah, Department of Computer Science
6  */
7 /*-
8  * SPDX-License-Identifier: BSD-3-Clause
9  *
10  * Copyright (c) 1982, 1986, 1989, 1993
11  *	The Regents of the University of California.  All rights reserved.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/endian.h>
43 #include <sys/bio.h>
44 #include <sys/buf.h>
45 #include <sys/limits.h>
46 #include <sys/lock.h>
47 #include <sys/mount.h>
48 #include <sys/vnode.h>
49 
50 #include <fs/ext2fs/fs.h>
51 #include <fs/ext2fs/inode.h>
52 #include <fs/ext2fs/ext2fs.h>
53 #include <fs/ext2fs/ext2_dinode.h>
54 #include <fs/ext2fs/ext2_extern.h>
55 #include <fs/ext2fs/ext2_mount.h>
56 
57 static int
58 ext2_ext_balloc(struct inode *ip, uint32_t lbn, int size,
59     struct ucred *cred, struct buf **bpp, int flags)
60 {
61 	struct m_ext2fs *fs;
62 	struct buf *bp = NULL;
63 	struct vnode *vp = ITOV(ip);
64 	daddr_t newblk;
65 	int blks, error, allocated;
66 
67 	fs = ip->i_e2fs;
68 	blks = howmany(size, fs->e2fs_bsize);
69 
70 	error = ext4_ext_get_blocks(ip, lbn, blks, cred, NULL, &allocated, &newblk);
71 	if (error)
72 		return (error);
73 
74 	if (allocated) {
75 		bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
76 		if(!bp)
77 			return (EIO);
78 	} else {
79 		error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
80 		if (error) {
81 			return (error);
82 		}
83 	}
84 
85 	bp->b_blkno = fsbtodb(fs, newblk);
86 	if (flags & BA_CLRBUF)
87 		vfs_bio_clrbuf(bp);
88 
89 	*bpp = bp;
90 
91 	return (error);
92 }
93 
94 /*
95  * Balloc defines the structure of filesystem storage
96  * by allocating the physical blocks on a device given
97  * the inode and the logical block number in a file.
98  */
99 int
100 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
101     struct buf **bpp, int flags)
102 {
103 	struct m_ext2fs *fs;
104 	struct ext2mount *ump;
105 	struct buf *bp, *nbp;
106 	struct vnode *vp = ITOV(ip);
107 	struct indir indirs[EXT2_NIADDR + 2];
108 	e4fs_daddr_t nb, newb;
109 	e2fs_daddr_t *bap, pref;
110 	int num, i, error;
111 
112 	*bpp = NULL;
113 	if (lbn < 0)
114 		return (EFBIG);
115 	fs = ip->i_e2fs;
116 	ump = ip->i_ump;
117 
118 	/*
119 	 * check if this is a sequential block allocation.
120 	 * If so, increment next_alloc fields to allow ext2_blkpref
121 	 * to make a good guess
122 	 */
123 	if (lbn == ip->i_next_alloc_block + 1) {
124 		ip->i_next_alloc_block++;
125 		ip->i_next_alloc_goal++;
126 	}
127 
128 	if (ip->i_flag & IN_E4EXTENTS)
129 		return (ext2_ext_balloc(ip, lbn, size, cred, bpp, flags));
130 
131 	/*
132 	 * The first EXT2_NDADDR blocks are direct blocks
133 	 */
134 	if (lbn < EXT2_NDADDR) {
135 		nb = ip->i_db[lbn];
136 		/*
137 		 * no new block is to be allocated, and no need to expand
138 		 * the file
139 		 */
140 		if (nb != 0) {
141 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
142 			if (error) {
143 				return (error);
144 			}
145 			bp->b_blkno = fsbtodb(fs, nb);
146 			if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
147 				*bpp = bp;
148 				return (0);
149 			}
150 		} else {
151 			EXT2_LOCK(ump);
152 			error = ext2_alloc(ip, lbn,
153 			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
154 			    fs->e2fs_bsize, cred, &newb);
155 			if (error)
156 				return (error);
157 			/*
158 			 * If the newly allocated block exceeds 32-bit limit,
159 			 * we can not use it in file block maps.
160 			 */
161 			if (newb > UINT_MAX)
162 				return (EFBIG);
163 			bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
164 			bp->b_blkno = fsbtodb(fs, newb);
165 			if (flags & BA_CLRBUF)
166 				vfs_bio_clrbuf(bp);
167 		}
168 		ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
169 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
170 		*bpp = bp;
171 		return (0);
172 	}
173 	/*
174 	 * Determine the number of levels of indirection.
175 	 */
176 	pref = 0;
177 	if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
178 		return (error);
179 #ifdef INVARIANTS
180 	if (num < 1)
181 		panic("ext2_balloc: ext2_getlbns returned indirect block");
182 #endif
183 	/*
184 	 * Fetch the first indirect block allocating if necessary.
185 	 */
186 	--num;
187 	nb = ip->i_ib[indirs[0].in_off];
188 	if (nb == 0) {
189 		EXT2_LOCK(ump);
190 		pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
191 		    EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
192 		if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
193 		    &newb)))
194 			return (error);
195 		if (newb > UINT_MAX)
196 			return (EFBIG);
197 		nb = newb;
198 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
199 		bp->b_blkno = fsbtodb(fs, newb);
200 		vfs_bio_clrbuf(bp);
201 		/*
202 		 * Write synchronously so that indirect blocks
203 		 * never point at garbage.
204 		 */
205 		if ((error = bwrite(bp)) != 0) {
206 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
207 			return (error);
208 		}
209 		ip->i_ib[indirs[0].in_off] = newb;
210 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
211 	}
212 	/*
213 	 * Fetch through the indirect blocks, allocating as necessary.
214 	 */
215 	for (i = 1;;) {
216 		error = bread(vp,
217 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
218 		if (error) {
219 			return (error);
220 		}
221 		bap = (e2fs_daddr_t *)bp->b_data;
222 		nb = le32toh(bap[indirs[i].in_off]);
223 		if (i == num)
224 			break;
225 		i += 1;
226 		if (nb != 0) {
227 			bqrelse(bp);
228 			continue;
229 		}
230 		EXT2_LOCK(ump);
231 		if (pref == 0)
232 			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
233 			    bp->b_lblkno);
234 		error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
235 		if (error) {
236 			brelse(bp);
237 			return (error);
238 		}
239 		if (newb > UINT_MAX)
240 			return (EFBIG);
241 		nb = newb;
242 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
243 		nbp->b_blkno = fsbtodb(fs, nb);
244 		vfs_bio_clrbuf(nbp);
245 		/*
246 		 * Write synchronously so that indirect blocks
247 		 * never point at garbage.
248 		 */
249 		if ((error = bwrite(nbp)) != 0) {
250 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
251 			brelse(bp);
252 			return (error);
253 		}
254 		bap[indirs[i - 1].in_off] = htole32(nb);
255 		/*
256 		 * If required, write synchronously, otherwise use
257 		 * delayed write.
258 		 */
259 		if (flags & IO_SYNC) {
260 			bwrite(bp);
261 		} else {
262 			if (bp->b_bufsize == fs->e2fs_bsize)
263 				bp->b_flags |= B_CLUSTEROK;
264 			bdwrite(bp);
265 		}
266 	}
267 	/*
268 	 * Get the data block, allocating if necessary.
269 	 */
270 	if (nb == 0) {
271 		EXT2_LOCK(ump);
272 		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
273 		    bp->b_lblkno);
274 		if ((error = ext2_alloc(ip,
275 		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
276 			brelse(bp);
277 			return (error);
278 		}
279 		if (newb > UINT_MAX)
280 			return (EFBIG);
281 		nb = newb;
282 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
283 		nbp->b_blkno = fsbtodb(fs, nb);
284 		if (flags & BA_CLRBUF)
285 			vfs_bio_clrbuf(nbp);
286 		bap[indirs[i].in_off] = htole32(nb);
287 		/*
288 		 * If required, write synchronously, otherwise use
289 		 * delayed write.
290 		 */
291 		if (flags & IO_SYNC) {
292 			bwrite(bp);
293 		} else {
294 			if (bp->b_bufsize == fs->e2fs_bsize)
295 				bp->b_flags |= B_CLUSTEROK;
296 			bdwrite(bp);
297 		}
298 		*bpp = nbp;
299 		return (0);
300 	}
301 	brelse(bp);
302 	if (flags & BA_CLRBUF) {
303 		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
304 
305 		if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
306 			error = cluster_read(vp, ip->i_size, lbn,
307 			    (int)fs->e2fs_bsize, NOCRED,
308 			    MAXBSIZE, seqcount, 0, &nbp);
309 		} else {
310 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
311 		}
312 		if (error) {
313 			brelse(nbp);
314 			return (error);
315 		}
316 	} else {
317 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
318 		nbp->b_blkno = fsbtodb(fs, nb);
319 	}
320 	*bpp = nbp;
321 	return (0);
322 }
323