2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95
30 * $FreeBSD: src/sys/ufs/ffs/ffs_balloc.c,v 1.26.2.1 2002/10/10 19:48:20 dillon Exp $
33 #include <sys/param.h>
34 #include <sys/systm.h>
38 #include <sys/mount.h>
39 #include <sys/vnode.h>
45 #include "ufs_extern.h"
48 #include "ffs_extern.h"
51 * ffs_balloc(struct vnode *a_vp, ufs_daddr_t a_lbn, int a_size,
52 * struct ucred *a_cred, int a_flags, struct buf *a_bpp)
54 * Balloc defines the structure of filesystem storage by allocating
55 * the physical blocks on a device given the inode and the logical
56 * block number in a file.
58 * NOTE: B_CLRBUF - this flag tells balloc to clear invalid portions
59 * of the buffer. However, any dirty bits will override missing
60 * valid bits. This case occurs when writable mmaps are truncated
64 ffs_balloc(struct vop_balloc_args *ap)
73 struct buf *bp, *nbp, *dbp;
75 struct indir indirs[UFS_NIADDR + 2];
76 ufs_daddr_t newb, *bap, pref;
77 int deallocated, osize, nsize, num, i, error;
78 ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[UFS_NIADDR + 1];
79 ufs_daddr_t *lbns_remfree, lbns[UFS_NIADDR + 1];
86 lbn = lblkno(fs, ap->a_startoffset);
87 size = blkoff(fs, ap->a_startoffset) + ap->a_size;
88 if (size > fs->fs_bsize)
89 panic("ffs_balloc: blk too big");
97 * The vnode must be locked for us to be able to safely mess
98 * around with the inode.
100 if (vn_islocked(vp) != LK_EXCLUSIVE) {
101 panic("ffs_balloc: vnode %p not exclusively locked!", vp);
105 * If the next write will extend the file into a new block,
106 * and the file is currently composed of a fragment
107 * this fragment has to be extended to be a full block.
109 nb = lblkno(fs, ip->i_size);
110 if (nb < UFS_NDADDR && nb < lbn) {
112 * The filesize prior to this write can fit in direct
113 * blocks (ex. fragmentation is possibly done)
114 * we are now extending the file write beyond
115 * the block which has end of the file prior to this write.
117 osize = blksize(fs, ip, nb);
119 * osize gives disk allocated size in the last block. It is
120 * either in fragments or a file system block size.
122 if (osize < fs->fs_bsize && osize > 0) {
123 /* A few fragments are already allocated, since the
124 * current extends beyond this block allocated the
125 * complete block as fragments are on in last block.
127 error = ffs_realloccg(ip, nb,
128 ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
129 osize, (int)fs->fs_bsize, cred, &bp);
132 if (DOINGSOFTDEP(vp))
133 softdep_setup_allocdirect(ip, nb,
134 dofftofsb(fs, bp->b_bio2.bio_offset),
135 ip->i_db[nb], fs->fs_bsize, osize, bp);
136 /* adjust the inode size, we just grew */
137 ip->i_size = smalllblktosize(fs, nb + 1);
138 ip->i_db[nb] = dofftofsb(fs, bp->b_bio2.bio_offset);
139 ip->i_flag |= IN_CHANGE | IN_UPDATE;
144 /* bp is already released here */
148 * The first UFS_NDADDR blocks are direct blocks
150 if (lbn < UFS_NDADDR) {
152 if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) {
153 error = bread(vp, lblktodoff(fs, lbn), fs->fs_bsize, &bp);
158 bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
164 * Consider need to reallocate a fragment.
166 osize = fragroundup(fs, blkoff(fs, ip->i_size));
167 nsize = fragroundup(fs, size);
168 if (nsize <= osize) {
169 error = bread(vp, lblktodoff(fs, lbn),
175 bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
178 * NOTE: ffs_realloccg() issues a bread().
180 error = ffs_realloccg(ip, lbn,
181 ffs_blkpref(ip, lbn, (int)lbn,
182 &ip->i_db[0]), osize, nsize, cred, &bp);
185 if (DOINGSOFTDEP(vp))
186 softdep_setup_allocdirect(ip, lbn,
187 dofftofsb(fs, bp->b_bio2.bio_offset),
188 nb, nsize, osize, bp);
191 if (ip->i_size < smalllblktosize(fs, lbn + 1))
192 nsize = fragroundup(fs, size);
194 nsize = fs->fs_bsize;
195 error = ffs_alloc(ip, lbn,
196 ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
200 bp = getblk(vp, lblktodoff(fs, lbn), nsize, 0, 0);
201 bp->b_bio2.bio_offset = fsbtodoff(fs, newb);
202 if (flags & B_CLRBUF)
204 if (DOINGSOFTDEP(vp))
205 softdep_setup_allocdirect(ip, lbn, newb, 0,
208 ip->i_db[lbn] = dofftofsb(fs, bp->b_bio2.bio_offset);
209 ip->i_flag |= IN_CHANGE | IN_UPDATE;
214 * Determine the number of levels of indirection.
217 if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
221 panic ("ffs_balloc: ufs_bmaparray returned indirect block");
224 * Get a handle on the data block buffer before working through
225 * indirect blocks to avoid a deadlock between the VM system holding
226 * a locked VM page and issuing a BMAP (which tries to lock the
227 * indirect blocks), and the filesystem holding a locked indirect
228 * block and then trying to read a data block (which tries to lock
229 * the underlying VM pages).
231 dbp = getblk(vp, lblktodoff(fs, lbn), fs->fs_bsize, 0, 0);
237 allocblk = allociblk;
243 * Fetch the first indirect block directly from the inode, allocating
247 nb = ip->i_ib[indirs[0].in_off];
249 pref = ffs_blkpref(ip, lbn, 0, NULL);
251 * If the filesystem has run out of space we can skip the
252 * full fsync/undo of the main [fail] case since no undo
253 * history has been built yet. Hence the goto fail2.
255 if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
260 *lbns_remfree++ = indirs[1].in_lbn;
261 bp = getblk(vp, lblktodoff(fs, indirs[1].in_lbn),
263 bp->b_bio2.bio_offset = fsbtodoff(fs, nb);
265 if (DOINGSOFTDEP(vp)) {
266 softdep_setup_allocdirect(ip,
267 UFS_NDADDR + indirs[0].in_off,
268 newb, 0, fs->fs_bsize, 0, bp);
272 * Write synchronously so that indirect blocks
273 * never point at garbage.
277 else if ((error = bwrite(bp)) != 0)
280 allocib = &ip->i_ib[indirs[0].in_off];
282 ip->i_flag |= IN_CHANGE | IN_UPDATE;
286 * Fetch through the indirect blocks, allocating as necessary.
289 error = bread(vp, lblktodoff(fs, indirs[i].in_lbn), (int)fs->fs_bsize, &bp);
294 bap = (ufs_daddr_t *)bp->b_data;
295 nb = bap[indirs[i].in_off];
304 pref = ffs_blkpref(ip, lbn, 0, NULL);
306 ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) != 0) {
312 *lbns_remfree++ = indirs[i].in_lbn;
313 nbp = getblk(vp, lblktodoff(fs, indirs[i].in_lbn),
315 nbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
317 if (DOINGSOFTDEP(vp)) {
318 softdep_setup_allocindir_meta(nbp, ip, bp,
319 indirs[i - 1].in_off, nb);
323 * Write synchronously so that indirect blocks
324 * never point at garbage.
326 if ((error = bwrite(nbp)) != 0) {
331 bap[indirs[i - 1].in_off] = nb;
332 if (allocib == NULL && unwindidx < 0)
335 * If required, write synchronously, otherwise use
338 if (flags & B_SYNC) {
341 if (bp->b_bufsize == fs->fs_bsize)
342 bp->b_flags |= B_CLUSTEROK;
348 * Get the data block, allocating if necessary. We have already
349 * called getblk() on the data block buffer, dbp. If we have to
350 * allocate it and B_CLRBUF has been set the inference is an intention
351 * to zero out the related disk blocks, so we do not have to issue
352 * a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is
353 * not set the caller intends to overwrite the entire contents of the
354 * buffer and we don't waste time trying to clean up the contents.
356 * bp references the current indirect block. When allocating,
357 * the block must be updated.
360 pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
361 error = ffs_alloc(ip,
362 lbn, pref, (int)fs->fs_bsize, cred, &newb);
369 *lbns_remfree++ = lbn;
370 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
371 if (flags & B_CLRBUF)
373 if (DOINGSOFTDEP(vp))
374 softdep_setup_allocindir_page(ip, lbn, bp,
375 indirs[i].in_off, nb, 0, dbp);
376 bap[indirs[i].in_off] = nb;
378 * If required, write synchronously, otherwise use
381 if (flags & B_SYNC) {
384 if (bp->b_bufsize == fs->fs_bsize)
385 bp->b_flags |= B_CLUSTEROK;
394 * At this point all related indirect blocks have been allocated
395 * if necessary and released. bp is no longer valid. dbp holds
396 * our getblk()'d data block.
398 * XXX we previously performed a cluster_read operation here.
400 if (flags & B_CLRBUF) {
402 * If B_CLRBUF is set we must validate the invalid portions
403 * of the buffer. This typically requires a read-before-
404 * write. The strategy call will fill in bio_offset in that
407 * If we hit this case we do a cluster read if possible
408 * since nearby data blocks are likely to be accessed soon
411 if ((dbp->b_flags & B_CACHE) == 0) {
413 seqcount = (flags & B_SEQMASK) >> B_SEQSHIFT;
415 (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
416 error = cluster_read(vp, (off_t)ip->i_size,
423 error = bread(vp, lblktodoff(fs, lbn),
424 (int)fs->fs_bsize, &dbp);
429 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
433 * If B_CLRBUF is not set the caller intends to overwrite
434 * the entire contents of the buffer. We can simply set
435 * bio_offset and we are done.
437 dbp->b_bio2.bio_offset = fsbtodoff(fs, nb);
443 * If we have failed part way through block allocation, we
444 * have to deallocate any indirect blocks that we have allocated.
445 * We have to fsync the file before we start to get rid of all
446 * of its dependencies so that we do not leave them dangling.
447 * We have to sync it at the end so that the soft updates code
448 * does not find any untracked changes. Although this is really
449 * slow, running out of disk space is not expected to be a common
450 * occurence. The error return from fsync is ignored as we already
451 * have an error to return to the user.
453 VOP_FSYNC(vp, MNT_WAIT, 0);
454 for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns;
455 blkp < allocblk; blkp++, lbns_remfree++) {
457 * We shall not leave the freed blocks on the vnode
458 * buffer object lists.
460 bp = getblk(vp, lblktodoff(fs, *lbns_remfree), fs->fs_bsize, 0, 0);
461 bp->b_flags |= (B_INVAL | B_RELBUF);
463 deallocated += fs->fs_bsize;
466 if (allocib != NULL) {
468 } else if (unwindidx >= 0) {
471 r = bread(vp, lblktodoff(fs, indirs[unwindidx].in_lbn), (int)fs->fs_bsize, &bp);
473 panic("Could not unwind indirect block, error %d", r);
476 bap = (ufs_daddr_t *)bp->b_data;
477 bap[indirs[unwindidx].in_off] = 0;
478 if (flags & B_SYNC) {
481 if (bp->b_bufsize == fs->fs_bsize)
482 bp->b_flags |= B_CLUSTEROK;
490 * Restore user's disk quota because allocation failed.
492 (void) ufs_chkdq(ip, (long)-btodb(deallocated), cred, FORCE);
494 ip->i_blocks -= btodb(deallocated);
495 ip->i_flag |= IN_CHANGE | IN_UPDATE;
497 VOP_FSYNC(vp, MNT_WAIT, 0);
500 * After the buffers are invalidated and on-disk pointers are
501 * cleared, free the blocks.
503 for (blkp = allociblk; blkp < allocblk; blkp++) {
504 ffs_blkfree(ip, *blkp, fs->fs_bsize);
508 * Cleanup the data block we getblk()'d before returning.