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.