xref: /freebsd/sys/fs/ext2fs/ext2_balloc.c (revision 4c1a82cea504df7a79f5bd8f7d0a41cacccff16e)
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/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 			brelse(bp);
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 				brelse(bp);
146 				return (error);
147 			}
148 			bp->b_blkno = fsbtodb(fs, nb);
149 			if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
150 				*bpp = bp;
151 				return (0);
152 			}
153 		} else {
154 			EXT2_LOCK(ump);
155 			error = ext2_alloc(ip, lbn,
156 			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
157 			    fs->e2fs_bsize, cred, &newb);
158 			if (error)
159 				return (error);
160 			/*
161 			 * If the newly allocated block exceeds 32-bit limit,
162 			 * we can not use it in file block maps.
163 			 */
164 			if (newb > UINT_MAX)
165 				return (EFBIG);
166 			bp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
167 			bp->b_blkno = fsbtodb(fs, newb);
168 			if (flags & BA_CLRBUF)
169 				vfs_bio_clrbuf(bp);
170 		}
171 		ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
172 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
173 		*bpp = bp;
174 		return (0);
175 	}
176 	/*
177 	 * Determine the number of levels of indirection.
178 	 */
179 	pref = 0;
180 	if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
181 		return (error);
182 #ifdef INVARIANTS
183 	if (num < 1)
184 		panic("ext2_balloc: ext2_getlbns returned indirect block");
185 #endif
186 	/*
187 	 * Fetch the first indirect block allocating if necessary.
188 	 */
189 	--num;
190 	nb = ip->i_ib[indirs[0].in_off];
191 	if (nb == 0) {
192 		EXT2_LOCK(ump);
193 		pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
194 		    EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
195 		if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
196 		    &newb)))
197 			return (error);
198 		if (newb > UINT_MAX)
199 			return (EFBIG);
200 		nb = newb;
201 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
202 		bp->b_blkno = fsbtodb(fs, newb);
203 		vfs_bio_clrbuf(bp);
204 		/*
205 		 * Write synchronously so that indirect blocks
206 		 * never point at garbage.
207 		 */
208 		if ((error = bwrite(bp)) != 0) {
209 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
210 			return (error);
211 		}
212 		ip->i_ib[indirs[0].in_off] = newb;
213 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
214 	}
215 	/*
216 	 * Fetch through the indirect blocks, allocating as necessary.
217 	 */
218 	for (i = 1;;) {
219 		error = bread(vp,
220 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
221 		if (error) {
222 			brelse(bp);
223 			return (error);
224 		}
225 		bap = (e2fs_daddr_t *)bp->b_data;
226 		nb = bap[indirs[i].in_off];
227 		if (i == num)
228 			break;
229 		i += 1;
230 		if (nb != 0) {
231 			bqrelse(bp);
232 			continue;
233 		}
234 		EXT2_LOCK(ump);
235 		if (pref == 0)
236 			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
237 			    bp->b_lblkno);
238 		error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
239 		if (error) {
240 			brelse(bp);
241 			return (error);
242 		}
243 		if (newb > UINT_MAX)
244 			return (EFBIG);
245 		nb = newb;
246 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
247 		nbp->b_blkno = fsbtodb(fs, nb);
248 		vfs_bio_clrbuf(nbp);
249 		/*
250 		 * Write synchronously so that indirect blocks
251 		 * never point at garbage.
252 		 */
253 		if ((error = bwrite(nbp)) != 0) {
254 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
255 			brelse(bp);
256 			return (error);
257 		}
258 		bap[indirs[i - 1].in_off] = nb;
259 		/*
260 		 * If required, write synchronously, otherwise use
261 		 * delayed write.
262 		 */
263 		if (flags & IO_SYNC) {
264 			bwrite(bp);
265 		} else {
266 			if (bp->b_bufsize == fs->e2fs_bsize)
267 				bp->b_flags |= B_CLUSTEROK;
268 			bdwrite(bp);
269 		}
270 	}
271 	/*
272 	 * Get the data block, allocating if necessary.
273 	 */
274 	if (nb == 0) {
275 		EXT2_LOCK(ump);
276 		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
277 		    bp->b_lblkno);
278 		if ((error = ext2_alloc(ip,
279 		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
280 			brelse(bp);
281 			return (error);
282 		}
283 		if (newb > UINT_MAX)
284 			return (EFBIG);
285 		nb = newb;
286 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
287 		nbp->b_blkno = fsbtodb(fs, nb);
288 		if (flags & BA_CLRBUF)
289 			vfs_bio_clrbuf(nbp);
290 		bap[indirs[i].in_off] = nb;
291 		/*
292 		 * If required, write synchronously, otherwise use
293 		 * delayed write.
294 		 */
295 		if (flags & IO_SYNC) {
296 			bwrite(bp);
297 		} else {
298 			if (bp->b_bufsize == fs->e2fs_bsize)
299 				bp->b_flags |= B_CLUSTEROK;
300 			bdwrite(bp);
301 		}
302 		*bpp = nbp;
303 		return (0);
304 	}
305 	brelse(bp);
306 	if (flags & BA_CLRBUF) {
307 		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
308 
309 		if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
310 			error = cluster_read(vp, ip->i_size, lbn,
311 			    (int)fs->e2fs_bsize, NOCRED,
312 			    MAXBSIZE, seqcount, 0, &nbp);
313 		} else {
314 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
315 		}
316 		if (error) {
317 			brelse(nbp);
318 			return (error);
319 		}
320 	} else {
321 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
322 		nbp->b_blkno = fsbtodb(fs, nb);
323 	}
324 	*bpp = nbp;
325 	return (0);
326 }
327