xref: /freebsd/sys/fs/ext2fs/ext2_balloc.c (revision 97cb52fa9aefd90fad38790fded50905aeeb9b9e)
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/lock.h>
46 #include <sys/mount.h>
47 #include <sys/vnode.h>
48 
49 #include <fs/ext2fs/fs.h>
50 #include <fs/ext2fs/inode.h>
51 #include <fs/ext2fs/ext2fs.h>
52 #include <fs/ext2fs/ext2_dinode.h>
53 #include <fs/ext2fs/ext2_extern.h>
54 #include <fs/ext2fs/ext2_mount.h>
55 
56 static int
57 ext2_ext_balloc(struct inode *ip, uint32_t lbn, int size,
58     struct ucred *cred, struct buf **bpp, int flags)
59 {
60 	struct m_ext2fs *fs;
61 	struct buf *bp = NULL;
62 	struct vnode *vp = ITOV(ip);
63 	uint32_t nb;
64 	int osize, nsize, blks, error, allocated;
65 
66 	fs = ip->i_e2fs;
67 	blks = howmany(size, fs->e2fs_bsize);
68 
69 	error = ext4_ext_get_blocks(ip, lbn, blks, cred, NULL, &allocated, &nb);
70 	if (error)
71 		return (error);
72 
73 	if (allocated) {
74 		if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
75 			nsize = fragroundup(fs, size);
76 		else
77 			nsize = fs->e2fs_bsize;
78 
79 		bp = getblk(vp, lbn, nsize, 0, 0, 0);
80 		if(!bp)
81 			return (EIO);
82 
83 		bp->b_blkno = fsbtodb(fs, nb);
84 		if (flags & BA_CLRBUF)
85 			vfs_bio_clrbuf(bp);
86 	} else {
87 		if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
88 
89 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
90 			if (error) {
91 				brelse(bp);
92 				return (error);
93 			}
94 			bp->b_blkno = fsbtodb(fs, nb);
95 			*bpp = bp;
96 			return (0);
97 		}
98 
99 		/*
100 		 * Consider need to reallocate a fragment.
101 		 */
102 		osize = fragroundup(fs, blkoff(fs, ip->i_size));
103 		nsize = fragroundup(fs, size);
104 		if (nsize <= osize) {
105 			error = bread(vp, lbn, osize, NOCRED, &bp);
106 			if (error) {
107 				brelse(bp);
108 				return (error);
109 			}
110 			bp->b_blkno = fsbtodb(fs, nb);
111 		} else {
112 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
113 			if (error) {
114 				brelse(bp);
115 				return (error);
116 			}
117 			bp->b_blkno = fsbtodb(fs, nb);
118 		}
119 	}
120 
121 	*bpp = bp;
122 
123 	return (error);
124 }
125 
126 /*
127  * Balloc defines the structure of filesystem storage
128  * by allocating the physical blocks on a device given
129  * the inode and the logical block number in a file.
130  */
131 int
132 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
133     struct buf **bpp, int flags)
134 {
135 	struct m_ext2fs *fs;
136 	struct ext2mount *ump;
137 	struct buf *bp, *nbp;
138 	struct vnode *vp = ITOV(ip);
139 	struct indir indirs[EXT2_NIADDR + 2];
140 	e4fs_daddr_t nb, newb;
141 	e2fs_daddr_t *bap, pref;
142 	int osize, nsize, num, i, error;
143 
144 	*bpp = NULL;
145 	if (lbn < 0)
146 		return (EFBIG);
147 	fs = ip->i_e2fs;
148 	ump = ip->i_ump;
149 
150 	/*
151 	 * check if this is a sequential block allocation.
152 	 * If so, increment next_alloc fields to allow ext2_blkpref
153 	 * to make a good guess
154 	 */
155 	if (lbn == ip->i_next_alloc_block + 1) {
156 		ip->i_next_alloc_block++;
157 		ip->i_next_alloc_goal++;
158 	}
159 
160 	if (ip->i_flag & IN_E4EXTENTS)
161 		return (ext2_ext_balloc(ip, lbn, size, cred, bpp, flags));
162 
163 	/*
164 	 * The first EXT2_NDADDR blocks are direct blocks
165 	 */
166 	if (lbn < EXT2_NDADDR) {
167 		nb = ip->i_db[lbn];
168 		/*
169 		 * no new block is to be allocated, and no need to expand
170 		 * the file
171 		 */
172 		if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
173 			error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
174 			if (error) {
175 				brelse(bp);
176 				return (error);
177 			}
178 			bp->b_blkno = fsbtodb(fs, nb);
179 			*bpp = bp;
180 			return (0);
181 		}
182 		if (nb != 0) {
183 			/*
184 			 * Consider need to reallocate a fragment.
185 			 */
186 			osize = fragroundup(fs, blkoff(fs, ip->i_size));
187 			nsize = fragroundup(fs, size);
188 			if (nsize <= osize) {
189 				error = bread(vp, lbn, osize, NOCRED, &bp);
190 				if (error) {
191 					brelse(bp);
192 					return (error);
193 				}
194 				bp->b_blkno = fsbtodb(fs, nb);
195 			} else {
196 				/*
197 				 * Godmar thinks: this shouldn't happen w/o
198 				 * fragments
199 				 */
200 				printf("nsize %d(%d) > osize %d(%d) nb %d\n",
201 				    (int)nsize, (int)size, (int)osize,
202 				    (int)ip->i_size, (int)nb);
203 				panic(
204 				    "ext2_balloc: Something is terribly wrong");
205 /*
206  * please note there haven't been any changes from here on -
207  * FFS seems to work.
208  */
209 			}
210 		} else {
211 			if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
212 				nsize = fragroundup(fs, size);
213 			else
214 				nsize = fs->e2fs_bsize;
215 			EXT2_LOCK(ump);
216 			error = ext2_alloc(ip, lbn,
217 			    ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
218 			    nsize, cred, &newb);
219 			if (error)
220 				return (error);
221 			bp = getblk(vp, lbn, nsize, 0, 0, 0);
222 			bp->b_blkno = fsbtodb(fs, newb);
223 			if (flags & BA_CLRBUF)
224 				vfs_bio_clrbuf(bp);
225 		}
226 		ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
227 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
228 		*bpp = bp;
229 		return (0);
230 	}
231 	/*
232 	 * Determine the number of levels of indirection.
233 	 */
234 	pref = 0;
235 	if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
236 		return (error);
237 #ifdef INVARIANTS
238 	if (num < 1)
239 		panic("ext2_balloc: ext2_getlbns returned indirect block");
240 #endif
241 	/*
242 	 * Fetch the first indirect block allocating if necessary.
243 	 */
244 	--num;
245 	nb = ip->i_ib[indirs[0].in_off];
246 	if (nb == 0) {
247 		EXT2_LOCK(ump);
248 		pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
249 		    EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
250 		if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
251 		    &newb)))
252 			return (error);
253 		nb = newb;
254 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
255 		bp->b_blkno = fsbtodb(fs, newb);
256 		vfs_bio_clrbuf(bp);
257 		/*
258 		 * Write synchronously so that indirect blocks
259 		 * never point at garbage.
260 		 */
261 		if ((error = bwrite(bp)) != 0) {
262 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
263 			return (error);
264 		}
265 		ip->i_ib[indirs[0].in_off] = newb;
266 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
267 	}
268 	/*
269 	 * Fetch through the indirect blocks, allocating as necessary.
270 	 */
271 	for (i = 1;;) {
272 		error = bread(vp,
273 		    indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
274 		if (error) {
275 			brelse(bp);
276 			return (error);
277 		}
278 		bap = (e2fs_daddr_t *)bp->b_data;
279 		nb = bap[indirs[i].in_off];
280 		if (i == num)
281 			break;
282 		i += 1;
283 		if (nb != 0) {
284 			bqrelse(bp);
285 			continue;
286 		}
287 		EXT2_LOCK(ump);
288 		if (pref == 0)
289 			pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
290 			    bp->b_lblkno);
291 		error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
292 		if (error) {
293 			brelse(bp);
294 			return (error);
295 		}
296 		nb = newb;
297 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
298 		nbp->b_blkno = fsbtodb(fs, nb);
299 		vfs_bio_clrbuf(nbp);
300 		/*
301 		 * Write synchronously so that indirect blocks
302 		 * never point at garbage.
303 		 */
304 		if ((error = bwrite(nbp)) != 0) {
305 			ext2_blkfree(ip, nb, fs->e2fs_bsize);
306 			EXT2_UNLOCK(ump);
307 			brelse(bp);
308 			return (error);
309 		}
310 		bap[indirs[i - 1].in_off] = nb;
311 		/*
312 		 * If required, write synchronously, otherwise use
313 		 * delayed write.
314 		 */
315 		if (flags & IO_SYNC) {
316 			bwrite(bp);
317 		} else {
318 			if (bp->b_bufsize == fs->e2fs_bsize)
319 				bp->b_flags |= B_CLUSTEROK;
320 			bdwrite(bp);
321 		}
322 	}
323 	/*
324 	 * Get the data block, allocating if necessary.
325 	 */
326 	if (nb == 0) {
327 		EXT2_LOCK(ump);
328 		pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
329 		    bp->b_lblkno);
330 		if ((error = ext2_alloc(ip,
331 		    lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
332 			brelse(bp);
333 			return (error);
334 		}
335 		nb = newb;
336 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
337 		nbp->b_blkno = fsbtodb(fs, nb);
338 		if (flags & BA_CLRBUF)
339 			vfs_bio_clrbuf(nbp);
340 		bap[indirs[i].in_off] = nb;
341 		/*
342 		 * If required, write synchronously, otherwise use
343 		 * delayed write.
344 		 */
345 		if (flags & IO_SYNC) {
346 			bwrite(bp);
347 		} else {
348 			if (bp->b_bufsize == fs->e2fs_bsize)
349 				bp->b_flags |= B_CLUSTEROK;
350 			bdwrite(bp);
351 		}
352 		*bpp = nbp;
353 		return (0);
354 	}
355 	brelse(bp);
356 	if (flags & BA_CLRBUF) {
357 		int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
358 
359 		if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
360 			error = cluster_read(vp, ip->i_size, lbn,
361 			    (int)fs->e2fs_bsize, NOCRED,
362 			    MAXBSIZE, seqcount, 0, &nbp);
363 		} else {
364 			error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
365 		}
366 		if (error) {
367 			brelse(nbp);
368 			return (error);
369 		}
370 	} else {
371 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
372 		nbp->b_blkno = fsbtodb(fs, nb);
373 	}
374 	*bpp = nbp;
375 	return (0);
376 }
377