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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 "opt_quota.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
40 #include <sys/mount.h>
41 #include <sys/vnode.h>
47 #include "ufs_extern.h"
50 #include "ffs_extern.h"
53 * ffs_balloc(struct vnode *a_vp, ufs_daddr_t a_lbn, int a_size,
54 * struct ucred *a_cred, int a_flags, struct buf *a_bpp)
56 * Balloc defines the structure of filesystem storage by allocating
57 * the physical blocks on a device given the inode and the logical
58 * block number in a file.
60 * NOTE: B_CLRBUF - this flag tells balloc to clear invalid portions
61 * of the buffer. However, any dirty bits will override missing
62 * valid bits. This case occurs when writable mmaps are truncated
66 ffs_balloc(struct vop_balloc_args
*ap
)
75 struct buf
*bp
, *nbp
, *dbp
;
77 struct indir indirs
[UFS_NIADDR
+ 2];
78 ufs_daddr_t newb
, *bap
, pref
;
79 int deallocated
, osize
, nsize
, num
, i
, error
;
80 ufs_daddr_t
*allocib
, *blkp
, *allocblk
, allociblk
[UFS_NIADDR
+ 1];
81 ufs_daddr_t
*lbns_remfree
, lbns
[UFS_NIADDR
+ 1];
88 lbn
= lblkno(fs
, ap
->a_startoffset
);
89 size
= blkoff(fs
, ap
->a_startoffset
) + ap
->a_size
;
90 if (size
> fs
->fs_bsize
)
91 panic("ffs_balloc: blk too big");
99 * The vnode must be locked for us to be able to safely mess
100 * around with the inode.
102 if (vn_islocked(vp
) != LK_EXCLUSIVE
) {
103 panic("ffs_balloc: vnode %p not exclusively locked!", vp
);
107 * If the next write will extend the file into a new block,
108 * and the file is currently composed of a fragment
109 * this fragment has to be extended to be a full block.
111 nb
= lblkno(fs
, ip
->i_size
);
112 if (nb
< UFS_NDADDR
&& nb
< lbn
) {
114 * The filesize prior to this write can fit in direct
115 * blocks (ex. fragmentation is possibly done)
116 * we are now extending the file write beyond
117 * the block which has end of the file prior to this write.
119 osize
= blksize(fs
, ip
, nb
);
121 * osize gives disk allocated size in the last block. It is
122 * either in fragments or a file system block size.
124 if (osize
< fs
->fs_bsize
&& osize
> 0) {
125 /* A few fragments are already allocated, since the
126 * current extends beyond this block allocated the
127 * complete block as fragments are on in last block.
129 error
= ffs_realloccg(ip
, nb
,
130 ffs_blkpref(ip
, nb
, (int)nb
, &ip
->i_db
[0]),
131 osize
, (int)fs
->fs_bsize
, cred
, &bp
);
134 if (DOINGSOFTDEP(vp
))
135 softdep_setup_allocdirect(ip
, nb
,
136 dofftofsb(fs
, bp
->b_bio2
.bio_offset
),
137 ip
->i_db
[nb
], fs
->fs_bsize
, osize
, bp
);
138 /* adjust the inode size, we just grew */
139 ip
->i_size
= smalllblktosize(fs
, nb
+ 1);
140 ip
->i_db
[nb
] = dofftofsb(fs
, bp
->b_bio2
.bio_offset
);
141 ip
->i_flag
|= IN_CHANGE
| IN_UPDATE
;
146 /* bp is already released here */
150 * The first UFS_NDADDR blocks are direct blocks
152 if (lbn
< UFS_NDADDR
) {
154 if (nb
!= 0 && ip
->i_size
>= smalllblktosize(fs
, lbn
+ 1)) {
155 error
= bread(vp
, lblktodoff(fs
, lbn
), fs
->fs_bsize
, &bp
);
160 bp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
166 * Consider need to reallocate a fragment.
168 osize
= fragroundup(fs
, blkoff(fs
, ip
->i_size
));
169 nsize
= fragroundup(fs
, size
);
170 if (nsize
<= osize
) {
171 error
= bread(vp
, lblktodoff(fs
, lbn
),
177 bp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
180 * NOTE: ffs_realloccg() issues a bread().
182 error
= ffs_realloccg(ip
, lbn
,
183 ffs_blkpref(ip
, lbn
, (int)lbn
,
184 &ip
->i_db
[0]), osize
, nsize
, cred
, &bp
);
187 if (DOINGSOFTDEP(vp
))
188 softdep_setup_allocdirect(ip
, lbn
,
189 dofftofsb(fs
, bp
->b_bio2
.bio_offset
),
190 nb
, nsize
, osize
, bp
);
193 if (ip
->i_size
< smalllblktosize(fs
, lbn
+ 1))
194 nsize
= fragroundup(fs
, size
);
196 nsize
= fs
->fs_bsize
;
197 error
= ffs_alloc(ip
, lbn
,
198 ffs_blkpref(ip
, lbn
, (int)lbn
, &ip
->i_db
[0]),
202 bp
= getblk(vp
, lblktodoff(fs
, lbn
), nsize
, 0, 0);
203 bp
->b_bio2
.bio_offset
= fsbtodoff(fs
, newb
);
204 if (flags
& B_CLRBUF
)
206 if (DOINGSOFTDEP(vp
))
207 softdep_setup_allocdirect(ip
, lbn
, newb
, 0,
210 ip
->i_db
[lbn
] = dofftofsb(fs
, bp
->b_bio2
.bio_offset
);
211 ip
->i_flag
|= IN_CHANGE
| IN_UPDATE
;
216 * Determine the number of levels of indirection.
219 if ((error
= ufs_getlbns(vp
, lbn
, indirs
, &num
)) != 0)
223 panic ("ffs_balloc: ufs_bmaparray returned indirect block");
226 * Get a handle on the data block buffer before working through
227 * indirect blocks to avoid a deadlock between the VM system holding
228 * a locked VM page and issuing a BMAP (which tries to lock the
229 * indirect blocks), and the filesystem holding a locked indirect
230 * block and then trying to read a data block (which tries to lock
231 * the underlying VM pages).
233 dbp
= getblk(vp
, lblktodoff(fs
, lbn
), fs
->fs_bsize
, 0, 0);
239 allocblk
= allociblk
;
245 * Fetch the first indirect block directly from the inode, allocating
249 nb
= ip
->i_ib
[indirs
[0].in_off
];
251 pref
= ffs_blkpref(ip
, lbn
, 0, NULL
);
253 * If the filesystem has run out of space we can skip the
254 * full fsync/undo of the main [fail] case since no undo
255 * history has been built yet. Hence the goto fail2.
257 if ((error
= ffs_alloc(ip
, lbn
, pref
, (int)fs
->fs_bsize
,
262 *lbns_remfree
++ = indirs
[1].in_lbn
;
263 bp
= getblk(vp
, lblktodoff(fs
, indirs
[1].in_lbn
),
265 bp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
267 if (DOINGSOFTDEP(vp
)) {
268 softdep_setup_allocdirect(ip
,
269 UFS_NDADDR
+ indirs
[0].in_off
,
270 newb
, 0, fs
->fs_bsize
, 0, bp
);
274 * Write synchronously so that indirect blocks
275 * never point at garbage.
279 else if ((error
= bwrite(bp
)) != 0)
282 allocib
= &ip
->i_ib
[indirs
[0].in_off
];
284 ip
->i_flag
|= IN_CHANGE
| IN_UPDATE
;
288 * Fetch through the indirect blocks, allocating as necessary.
291 error
= bread(vp
, lblktodoff(fs
, indirs
[i
].in_lbn
), (int)fs
->fs_bsize
, &bp
);
296 bap
= (ufs_daddr_t
*)bp
->b_data
;
297 nb
= bap
[indirs
[i
].in_off
];
306 pref
= ffs_blkpref(ip
, lbn
, 0, NULL
);
308 ffs_alloc(ip
, lbn
, pref
, (int)fs
->fs_bsize
, cred
, &newb
)) != 0) {
314 *lbns_remfree
++ = indirs
[i
].in_lbn
;
315 nbp
= getblk(vp
, lblktodoff(fs
, indirs
[i
].in_lbn
),
317 nbp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
319 if (DOINGSOFTDEP(vp
)) {
320 softdep_setup_allocindir_meta(nbp
, ip
, bp
,
321 indirs
[i
- 1].in_off
, nb
);
325 * Write synchronously so that indirect blocks
326 * never point at garbage.
328 if ((error
= bwrite(nbp
)) != 0) {
333 bap
[indirs
[i
- 1].in_off
] = nb
;
334 if (allocib
== NULL
&& unwindidx
< 0)
337 * If required, write synchronously, otherwise use
340 if (flags
& B_SYNC
) {
343 if (bp
->b_bufsize
== fs
->fs_bsize
)
344 bp
->b_flags
|= B_CLUSTEROK
;
350 * Get the data block, allocating if necessary. We have already
351 * called getblk() on the data block buffer, dbp. If we have to
352 * allocate it and B_CLRBUF has been set the inference is an intention
353 * to zero out the related disk blocks, so we do not have to issue
354 * a read. Instead we simply call vfs_bio_clrbuf(). If B_CLRBUF is
355 * not set the caller intends to overwrite the entire contents of the
356 * buffer and we don't waste time trying to clean up the contents.
358 * bp references the current indirect block. When allocating,
359 * the block must be updated.
362 pref
= ffs_blkpref(ip
, lbn
, indirs
[i
].in_off
, &bap
[0]);
363 error
= ffs_alloc(ip
,
364 lbn
, pref
, (int)fs
->fs_bsize
, cred
, &newb
);
371 *lbns_remfree
++ = lbn
;
372 dbp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
373 if (flags
& B_CLRBUF
)
375 if (DOINGSOFTDEP(vp
))
376 softdep_setup_allocindir_page(ip
, lbn
, bp
,
377 indirs
[i
].in_off
, nb
, 0, dbp
);
378 bap
[indirs
[i
].in_off
] = nb
;
380 * If required, write synchronously, otherwise use
383 if (flags
& B_SYNC
) {
386 if (bp
->b_bufsize
== fs
->fs_bsize
)
387 bp
->b_flags
|= B_CLUSTEROK
;
396 * At this point all related indirect blocks have been allocated
397 * if necessary and released. bp is no longer valid. dbp holds
398 * our getblk()'d data block.
400 * XXX we previously performed a cluster_read operation here.
402 if (flags
& B_CLRBUF
) {
404 * If B_CLRBUF is set we must validate the invalid portions
405 * of the buffer. This typically requires a read-before-
406 * write. The strategy call will fill in bio_offset in that
409 * If we hit this case we do a cluster read if possible
410 * since nearby data blocks are likely to be accessed soon
413 if ((dbp
->b_flags
& B_CACHE
) == 0) {
415 seqcount
= (flags
& B_SEQMASK
) >> B_SEQSHIFT
;
417 (vp
->v_mount
->mnt_flag
& MNT_NOCLUSTERR
) == 0) {
418 error
= cluster_read(vp
, (off_t
)ip
->i_size
,
425 error
= bread(vp
, lblktodoff(fs
, lbn
),
426 (int)fs
->fs_bsize
, &dbp
);
431 dbp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
435 * If B_CLRBUF is not set the caller intends to overwrite
436 * the entire contents of the buffer. We can simply set
437 * bio_offset and we are done.
439 dbp
->b_bio2
.bio_offset
= fsbtodoff(fs
, nb
);
445 * If we have failed part way through block allocation, we
446 * have to deallocate any indirect blocks that we have allocated.
447 * We have to fsync the file before we start to get rid of all
448 * of its dependencies so that we do not leave them dangling.
449 * We have to sync it at the end so that the soft updates code
450 * does not find any untracked changes. Although this is really
451 * slow, running out of disk space is not expected to be a common
452 * occurence. The error return from fsync is ignored as we already
453 * have an error to return to the user.
455 VOP_FSYNC(vp
, MNT_WAIT
, 0);
456 for (deallocated
= 0, blkp
= allociblk
, lbns_remfree
= lbns
;
457 blkp
< allocblk
; blkp
++, lbns_remfree
++) {
459 * We shall not leave the freed blocks on the vnode
460 * buffer object lists.
462 bp
= getblk(vp
, lblktodoff(fs
, *lbns_remfree
), fs
->fs_bsize
, 0, 0);
463 bp
->b_flags
|= (B_INVAL
| B_RELBUF
);
465 deallocated
+= fs
->fs_bsize
;
468 if (allocib
!= NULL
) {
470 } else if (unwindidx
>= 0) {
473 r
= bread(vp
, lblktodoff(fs
, indirs
[unwindidx
].in_lbn
), (int)fs
->fs_bsize
, &bp
);
475 panic("Could not unwind indirect block, error %d", r
);
478 bap
= (ufs_daddr_t
*)bp
->b_data
;
479 bap
[indirs
[unwindidx
].in_off
] = 0;
480 if (flags
& B_SYNC
) {
483 if (bp
->b_bufsize
== fs
->fs_bsize
)
484 bp
->b_flags
|= B_CLUSTEROK
;
492 * Restore user's disk quota because allocation failed.
494 (void) ufs_chkdq(ip
, (long)-btodb(deallocated
), cred
, FORCE
);
496 ip
->i_blocks
-= btodb(deallocated
);
497 ip
->i_flag
|= IN_CHANGE
| IN_UPDATE
;
499 VOP_FSYNC(vp
, MNT_WAIT
, 0);
502 * After the buffers are invalidated and on-disk pointers are
503 * cleared, free the blocks.
505 for (blkp
= allociblk
; blkp
< allocblk
; blkp
++) {
506 ffs_blkfree(ip
, *blkp
, fs
->fs_bsize
);
510 * Cleanup the data block we getblk()'d before returning.