xref: /freebsd/sys/fs/ext2fs/ext2_balloc.c (revision e17f5b1d)
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  * $FreeBSD$
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/endian.h>
44 #include <sys/bio.h>
45 #include <sys/buf.h>
46 #include <sys/limits.h>
47 #include <sys/lock.h>
48 #include <sys/mount.h>
49 #include <sys/vnode.h>
50 
51 #include <fs/ext2fs/fs.h>
52 #include <fs/ext2fs/inode.h>
53 #include <fs/ext2fs/ext2fs.h>
54 #include <fs/ext2fs/ext2_dinode.h>
55 #include <fs/ext2fs/ext2_extern.h>
56 #include <fs/ext2fs/ext2_mount.h>
57 
58 static int
59 ext2_ext_balloc(struct inode *ip, uint32_t lbn, int size,
60     struct ucred *cred, struct buf **bpp, int flags)
61 {
62 	struct m_ext2fs *fs;
63 	struct buf *bp = NULL;
64 	struct vnode *vp = ITOV(ip);
65 	daddr_t newblk;
66 	int blks, error, allocated;
67 
68 	fs = ip->i_e2fs;
69 	blks = howmany(size, fs->e2fs_bsize);
70 
71 	error = ext4_ext_get_blocks(ip, lbn, blks, cred, NULL, &allocated, &newblk);
72 	if (error)
73 		return (error);
74 
75 	if (allocated) {
76 		bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
77 		if(!bp)
78 			return (EIO);
79 	} else {
80 		error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
81 		if (error) {
82 			return (error);
83 		}
84 	}
85 
86 
87 	bp->b_blkno = fsbtodb(fs, newblk);
88 	if (flags & BA_CLRBUF)
89 		vfs_bio_clrbuf(bp);
90 
91 	*bpp = bp;
92 
93 	return (error);
94 }
95 
96 /*
97  * Balloc defines the structure of filesystem storage
98  * by allocating the physical blocks on a device given
99  * the inode and the logical block number in a file.
100  */
101 int
102 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
103     struct buf **bpp, int flags)
104 {
105 	struct m_ext2fs *fs;
106 	struct ext2mount *ump;
107 	struct buf *bp, *nbp;
108 	struct vnode *vp = ITOV(ip);
109 	struct indir indirs[EXT2_NIADDR + 2];
110 	e4fs_daddr_t nb, newb;
111 	e2fs_daddr_t *bap, pref;
112 	int num, i, error;
113 
114 	*bpp = NULL;
115 	if (lbn < 0)
116 		return (EFBIG);
117 	fs = ip->i_e2fs;
118 	ump = ip->i_ump;
119 
120 	/*
121 	 * check if this is a sequential block allocation.
122 	 * If so, increment next_alloc fields to allow ext2_blkpref
123 	 * to make a good guess
124 	 */
125 	if (lbn == ip->i_next_alloc_block + 1) {
126 		ip->i_next_alloc_block++;
127 		ip->i_next_alloc_goal++;
128 	}
129 
130 	if (ip->i_flag & IN_E4EXTENTS)
131 		return (ext2_ext_balloc(ip, lbn, size, cred, bpp, flags));
132 
133 	/*
134 	 * The first EXT2_NDADDR blocks are direct blocks
135 	 */
136 	if (lbn < EXT2_NDADDR) {
137 		nb = ip->i_db[lbn];
138 		/*
139 		 * no new block is to be allocated, and no need to expand
140 		 * the file
141 		 */
142 		if (nb != 0) {
143 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
144 			if (error) {
145 				return (error);
146 			}
147 			bp->b_blkno = fsbtodb(fs, nb);
148 			if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
149 				*bpp = bp;
150 				return (0);
151 			}
152 		} else {
153 			EXT2_LOCK(ump);
154 			error = ext2_alloc(ip, lbn,
155 			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
156 			    fs->e2fs_bsize, cred, &newb);
157 			if (error)
158 				return (error);
159 			/*
160 			 * If the newly allocated block exceeds 32-bit limit,
161 			 * we can not use it in file block maps.
162 			 */
163 			if (newb > UINT_MAX)
164 				return (EFBIG);
165 			bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
166 			bp->b_blkno = fsbtodb(fs, newb);
167 			if (flags & BA_CLRBUF)
168 				vfs_bio_clrbuf(bp);
169 		}
170 		ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
171 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
172 		*bpp = bp;
173 		return (0);
174 	}
175 	/*
176 	 * Determine the number of levels of indirection.
177 	 */
178 	pref = 0;
179 	if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
180 		return (error);
181 #ifdef INVARIANTS
182 	if (num < 1)
183 		panic("ext2_balloc: ext2_getlbns returned indirect block");
184 #endif
185 	/*
186 	 * Fetch the first indirect block allocating if necessary.
187 	 */
188 	--num;
189 	nb = ip->i_ib[indirs[0].in_off];
190 	if (nb == 0) {
191 		EXT2_LOCK(ump);
192 		pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
193 		    EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
194 		if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
195 		    &newb)))
196 			return (error);
197 		if (newb > UINT_MAX)
198 			return (EFBIG);
199 		nb = newb;
200 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
201 		bp->b_blkno = fsbtodb(fs, newb);
202 		vfs_bio_clrbuf(bp);
203 		/*
204 		 * Write synchronously so that indirect blocks
205 		 * never point at garbage.
206 		 */
207 		if ((error = bwrite(bp)) != 0) {
208 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
209 			return (error);
210 		}
211 		ip->i_ib[indirs[0].in_off] = newb;
212 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
213 	}
214 	/*
215 	 * Fetch through the indirect blocks, allocating as necessary.
216 	 */
217 	for (i = 1;;) {
218 		error = bread(vp,
219 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
220 		if (error) {
221 			return (error);
222 		}
223 		bap = (e2fs_daddr_t *)bp->b_data;
224 		nb = le32toh(bap[indirs[i].in_off]);
225 		if (i == num)
226 			break;
227 		i += 1;
228 		if (nb != 0) {
229 			bqrelse(bp);
230 			continue;
231 		}
232 		EXT2_LOCK(ump);
233 		if (pref == 0)
234 			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
235 			    bp->b_lblkno);
236 		error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
237 		if (error) {
238 			brelse(bp);
239 			return (error);
240 		}
241 		if (newb > UINT_MAX)
242 			return (EFBIG);
243 		nb = newb;
244 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
245 		nbp->b_blkno = fsbtodb(fs, nb);
246 		vfs_bio_clrbuf(nbp);
247 		/*
248 		 * Write synchronously so that indirect blocks
249 		 * never point at garbage.
250 		 */
251 		if ((error = bwrite(nbp)) != 0) {
252 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
253 			brelse(bp);
254 			return (error);
255 		}
256 		bap[indirs[i - 1].in_off] = htole32(nb);
257 		/*
258 		 * If required, write synchronously, otherwise use
259 		 * delayed write.
260 		 */
261 		if (flags & IO_SYNC) {
262 			bwrite(bp);
263 		} else {
264 			if (bp->b_bufsize == fs->e2fs_bsize)
265 				bp->b_flags |= B_CLUSTEROK;
266 			bdwrite(bp);
267 		}
268 	}
269 	/*
270 	 * Get the data block, allocating if necessary.
271 	 */
272 	if (nb == 0) {
273 		EXT2_LOCK(ump);
274 		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
275 		    bp->b_lblkno);
276 		if ((error = ext2_alloc(ip,
277 		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
278 			brelse(bp);
279 			return (error);
280 		}
281 		if (newb > UINT_MAX)
282 			return (EFBIG);
283 		nb = newb;
284 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
285 		nbp->b_blkno = fsbtodb(fs, nb);
286 		if (flags & BA_CLRBUF)
287 			vfs_bio_clrbuf(nbp);
288 		bap[indirs[i].in_off] = htole32(nb);
289 		/*
290 		 * If required, write synchronously, otherwise use
291 		 * delayed write.
292 		 */
293 		if (flags & IO_SYNC) {
294 			bwrite(bp);
295 		} else {
296 			if (bp->b_bufsize == fs->e2fs_bsize)
297 				bp->b_flags |= B_CLUSTEROK;
298 			bdwrite(bp);
299 		}
300 		*bpp = nbp;
301 		return (0);
302 	}
303 	brelse(bp);
304 	if (flags & BA_CLRBUF) {
305 		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
306 
307 		if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
308 			error = cluster_read(vp, ip->i_size, lbn,
309 			    (int)fs->e2fs_bsize, NOCRED,
310 			    MAXBSIZE, seqcount, 0, &nbp);
311 		} else {
312 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
313 		}
314 		if (error) {
315 			brelse(nbp);
316 			return (error);
317 		}
318 	} else {
319 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
320 		nbp->b_blkno = fsbtodb(fs, nb);
321 	}
322 	*bpp = nbp;
323 	return (0);
324 }
325