xref: /freebsd/sys/fs/ext2fs/ext2_balloc.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/endian.h>
41 #include <sys/bio.h>
42 #include <sys/buf.h>
43 #include <sys/limits.h>
44 #include <sys/lock.h>
45 #include <sys/mount.h>
46 #include <sys/vnode.h>
47 
48 #include <fs/ext2fs/fs.h>
49 #include <fs/ext2fs/inode.h>
50 #include <fs/ext2fs/ext2fs.h>
51 #include <fs/ext2fs/ext2_dinode.h>
52 #include <fs/ext2fs/ext2_extern.h>
53 #include <fs/ext2fs/ext2_mount.h>
54 
55 static int
56 ext2_ext_balloc(struct inode *ip, uint32_t lbn, int size,
57     struct ucred *cred, struct buf **bpp, int flags)
58 {
59 	struct m_ext2fs *fs;
60 	struct buf *bp = NULL;
61 	struct vnode *vp = ITOV(ip);
62 	daddr_t newblk;
63 	int blks, error, allocated;
64 
65 	fs = ip->i_e2fs;
66 	blks = howmany(size, fs->e2fs_bsize);
67 
68 	error = ext4_ext_get_blocks(ip, lbn, blks, cred, NULL, &allocated, &newblk);
69 	if (error)
70 		return (error);
71 
72 	if (allocated) {
73 		bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
74 		if(!bp)
75 			return (EIO);
76 	} else {
77 		error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
78 		if (error) {
79 			return (error);
80 		}
81 	}
82 
83 	bp->b_blkno = fsbtodb(fs, newblk);
84 	if (flags & BA_CLRBUF)
85 		vfs_bio_clrbuf(bp);
86 
87 	*bpp = bp;
88 
89 	return (error);
90 }
91 
92 /*
93  * Balloc defines the structure of filesystem storage
94  * by allocating the physical blocks on a device given
95  * the inode and the logical block number in a file.
96  */
97 int
98 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
99     struct buf **bpp, int flags)
100 {
101 	struct m_ext2fs *fs;
102 	struct ext2mount *ump;
103 	struct buf *bp, *nbp;
104 	struct vnode *vp = ITOV(ip);
105 	struct indir indirs[EXT2_NIADDR + 2];
106 	e4fs_daddr_t nb, newb;
107 	e2fs_daddr_t *bap, pref;
108 	int num, i, error;
109 
110 	*bpp = NULL;
111 	if (lbn < 0)
112 		return (EFBIG);
113 	fs = ip->i_e2fs;
114 	ump = ip->i_ump;
115 
116 	/*
117 	 * check if this is a sequential block allocation.
118 	 * If so, increment next_alloc fields to allow ext2_blkpref
119 	 * to make a good guess
120 	 */
121 	if (lbn == ip->i_next_alloc_block + 1) {
122 		ip->i_next_alloc_block++;
123 		ip->i_next_alloc_goal++;
124 	}
125 
126 	if (ip->i_flag & IN_E4EXTENTS)
127 		return (ext2_ext_balloc(ip, lbn, size, cred, bpp, flags));
128 
129 	/*
130 	 * The first EXT2_NDADDR blocks are direct blocks
131 	 */
132 	if (lbn < EXT2_NDADDR) {
133 		nb = ip->i_db[lbn];
134 		/*
135 		 * no new block is to be allocated, and no need to expand
136 		 * the file
137 		 */
138 		if (nb != 0) {
139 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
140 			if (error) {
141 				return (error);
142 			}
143 			bp->b_blkno = fsbtodb(fs, nb);
144 			if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
145 				*bpp = bp;
146 				return (0);
147 			}
148 		} else {
149 			EXT2_LOCK(ump);
150 			error = ext2_alloc(ip, lbn,
151 			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
152 			    fs->e2fs_bsize, cred, &newb);
153 			if (error)
154 				return (error);
155 			/*
156 			 * If the newly allocated block exceeds 32-bit limit,
157 			 * we can not use it in file block maps.
158 			 */
159 			if (newb > UINT_MAX)
160 				return (EFBIG);
161 			bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
162 			bp->b_blkno = fsbtodb(fs, newb);
163 			if (flags & BA_CLRBUF)
164 				vfs_bio_clrbuf(bp);
165 		}
166 		ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
167 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
168 		*bpp = bp;
169 		return (0);
170 	}
171 	/*
172 	 * Determine the number of levels of indirection.
173 	 */
174 	pref = 0;
175 	if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
176 		return (error);
177 #ifdef INVARIANTS
178 	if (num < 1)
179 		panic("ext2_balloc: ext2_getlbns returned indirect block");
180 #endif
181 	/*
182 	 * Fetch the first indirect block allocating if necessary.
183 	 */
184 	--num;
185 	nb = ip->i_ib[indirs[0].in_off];
186 	if (nb == 0) {
187 		EXT2_LOCK(ump);
188 		pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
189 		    EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
190 		if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
191 		    &newb)))
192 			return (error);
193 		if (newb > UINT_MAX)
194 			return (EFBIG);
195 		nb = newb;
196 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
197 		bp->b_blkno = fsbtodb(fs, newb);
198 		vfs_bio_clrbuf(bp);
199 		/*
200 		 * Write synchronously so that indirect blocks
201 		 * never point at garbage.
202 		 */
203 		if ((error = bwrite(bp)) != 0) {
204 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
205 			return (error);
206 		}
207 		ip->i_ib[indirs[0].in_off] = newb;
208 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
209 	}
210 	/*
211 	 * Fetch through the indirect blocks, allocating as necessary.
212 	 */
213 	for (i = 1;;) {
214 		error = bread(vp,
215 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
216 		if (error) {
217 			return (error);
218 		}
219 		bap = (e2fs_daddr_t *)bp->b_data;
220 		nb = le32toh(bap[indirs[i].in_off]);
221 		if (i == num)
222 			break;
223 		i += 1;
224 		if (nb != 0) {
225 			bqrelse(bp);
226 			continue;
227 		}
228 		EXT2_LOCK(ump);
229 		if (pref == 0)
230 			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
231 			    bp->b_lblkno);
232 		error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
233 		if (error) {
234 			brelse(bp);
235 			return (error);
236 		}
237 		if (newb > UINT_MAX)
238 			return (EFBIG);
239 		nb = newb;
240 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
241 		nbp->b_blkno = fsbtodb(fs, nb);
242 		vfs_bio_clrbuf(nbp);
243 		/*
244 		 * Write synchronously so that indirect blocks
245 		 * never point at garbage.
246 		 */
247 		if ((error = bwrite(nbp)) != 0) {
248 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
249 			brelse(bp);
250 			return (error);
251 		}
252 		bap[indirs[i - 1].in_off] = htole32(nb);
253 		/*
254 		 * If required, write synchronously, otherwise use
255 		 * delayed write.
256 		 */
257 		if (flags & IO_SYNC) {
258 			bwrite(bp);
259 		} else {
260 			if (bp->b_bufsize == fs->e2fs_bsize)
261 				bp->b_flags |= B_CLUSTEROK;
262 			bdwrite(bp);
263 		}
264 	}
265 	/*
266 	 * Get the data block, allocating if necessary.
267 	 */
268 	if (nb == 0) {
269 		EXT2_LOCK(ump);
270 		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
271 		    bp->b_lblkno);
272 		if ((error = ext2_alloc(ip,
273 		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
274 			brelse(bp);
275 			return (error);
276 		}
277 		if (newb > UINT_MAX)
278 			return (EFBIG);
279 		nb = newb;
280 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
281 		nbp->b_blkno = fsbtodb(fs, nb);
282 		if (flags & BA_CLRBUF)
283 			vfs_bio_clrbuf(nbp);
284 		bap[indirs[i].in_off] = htole32(nb);
285 		/*
286 		 * If required, write synchronously, otherwise use
287 		 * delayed write.
288 		 */
289 		if (flags & IO_SYNC) {
290 			bwrite(bp);
291 		} else {
292 			if (bp->b_bufsize == fs->e2fs_bsize)
293 				bp->b_flags |= B_CLUSTEROK;
294 			bdwrite(bp);
295 		}
296 		*bpp = nbp;
297 		return (0);
298 	}
299 	brelse(bp);
300 	if (flags & BA_CLRBUF) {
301 		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
302 
303 		if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
304 			error = cluster_read(vp, ip->i_size, lbn,
305 			    (int)fs->e2fs_bsize, NOCRED,
306 			    MAXBSIZE, seqcount, 0, &nbp);
307 		} else {
308 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
309 		}
310 		if (error) {
311 			brelse(nbp);
312 			return (error);
313 		}
314 	} else {
315 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
316 		nbp->b_blkno = fsbtodb(fs, nb);
317 	}
318 	*bpp = nbp;
319 	return (0);
320 }
321