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authorDavid Teigland <teigland@redhat.com>2006-01-16 11:50:04 -0500
committerSteven Whitehouse <swhiteho@redhat.com>2006-01-16 11:50:04 -0500
commitb3b94faa5fe5968827ba0640ee9fba4b3e7f736e (patch)
tree70bd6068b050d2c46e338484f8b03fae4365c6c3 /fs/gfs2/bmap.c
parentf7825dcf8c7301cfd3724eb40c5b443cc85ab7b8 (diff)
[GFS2] The core of GFS2
This patch contains all the core files for GFS2. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/bmap.c')
-rw-r--r--fs/gfs2/bmap.c1206
1 files changed, 1206 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
new file mode 100644
index 000000000000..4b4e295b3bf5
--- /dev/null
+++ b/fs/gfs2/bmap.c
@@ -0,0 +1,1206 @@
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License v.2.
8 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <asm/semaphore.h>
16
17#include "gfs2.h"
18#include "bmap.h"
19#include "glock.h"
20#include "inode.h"
21#include "jdata.h"
22#include "meta_io.h"
23#include "page.h"
24#include "quota.h"
25#include "rgrp.h"
26#include "trans.h"
27
28/* This doesn't need to be that large as max 64 bit pointers in a 4k
29 * block is 512, so __u16 is fine for that. It saves stack space to
30 * keep it small.
31 */
32struct metapath {
33 __u16 mp_list[GFS2_MAX_META_HEIGHT];
34};
35
36typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh,
37 struct buffer_head *bh, uint64_t *top,
38 uint64_t *bottom, unsigned int height,
39 void *data);
40
41struct strip_mine {
42 int sm_first;
43 unsigned int sm_height;
44};
45
46/**
47 * @gfs2_unstuffer_sync - Synchronously unstuff a dinode
48 * @ip:
49 * @dibh:
50 * @block:
51 * @private:
52 *
53 * Cheat and use a metadata buffer instead of a data page.
54 *
55 * Returns: errno
56 */
57
58int gfs2_unstuffer_sync(struct gfs2_inode *ip, struct buffer_head *dibh,
59 uint64_t block, void *private)
60{
61 struct buffer_head *bh;
62 int error;
63
64 bh = gfs2_meta_new(ip->i_gl, block);
65
66 gfs2_buffer_copy_tail(bh, 0, dibh, sizeof(struct gfs2_dinode));
67
68 set_buffer_dirty(bh);
69 error = sync_dirty_buffer(bh);
70
71 brelse(bh);
72
73 return error;
74}
75
76/**
77 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
78 * @ip: The GFS2 inode to unstuff
79 * @unstuffer: the routine that handles unstuffing a non-zero length file
80 * @private: private data for the unstuffer
81 *
82 * This routine unstuffs a dinode and returns it to a "normal" state such
83 * that the height can be grown in the traditional way.
84 *
85 * Returns: errno
86 */
87
88int gfs2_unstuff_dinode(struct gfs2_inode *ip, gfs2_unstuffer_t unstuffer,
89 void *private)
90{
91 struct buffer_head *bh, *dibh;
92 uint64_t block = 0;
93 int journaled = gfs2_is_jdata(ip);
94 int error;
95
96 down_write(&ip->i_rw_mutex);
97
98 error = gfs2_meta_inode_buffer(ip, &dibh);
99 if (error)
100 goto out;
101
102 if (ip->i_di.di_size) {
103 /* Get a free block, fill it with the stuffed data,
104 and write it out to disk */
105
106 if (journaled) {
107 block = gfs2_alloc_meta(ip);
108
109 error = gfs2_jdata_get_buffer(ip, block, 1, &bh);
110 if (error)
111 goto out_brelse;
112 gfs2_buffer_copy_tail(bh,
113 sizeof(struct gfs2_meta_header),
114 dibh, sizeof(struct gfs2_dinode));
115 brelse(bh);
116 } else {
117 block = gfs2_alloc_data(ip);
118
119 error = unstuffer(ip, dibh, block, private);
120 if (error)
121 goto out_brelse;
122 }
123 }
124
125 /* Set up the pointer to the new block */
126
127 gfs2_trans_add_bh(ip->i_gl, dibh);
128
129 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
130
131 if (ip->i_di.di_size) {
132 *(uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode)) = cpu_to_be64(block);
133 ip->i_di.di_blocks++;
134 }
135
136 ip->i_di.di_height = 1;
137
138 gfs2_dinode_out(&ip->i_di, dibh->b_data);
139
140 out_brelse:
141 brelse(dibh);
142
143 out:
144 up_write(&ip->i_rw_mutex);
145
146 return error;
147}
148
149/**
150 * calc_tree_height - Calculate the height of a metadata tree
151 * @ip: The GFS2 inode
152 * @size: The proposed size of the file
153 *
154 * Work out how tall a metadata tree needs to be in order to accommodate a
155 * file of a particular size. If size is less than the current size of
156 * the inode, then the current size of the inode is used instead of the
157 * supplied one.
158 *
159 * Returns: the height the tree should be
160 */
161
162static unsigned int calc_tree_height(struct gfs2_inode *ip, uint64_t size)
163{
164 struct gfs2_sbd *sdp = ip->i_sbd;
165 uint64_t *arr;
166 unsigned int max, height;
167
168 if (ip->i_di.di_size > size)
169 size = ip->i_di.di_size;
170
171 if (gfs2_is_jdata(ip)) {
172 arr = sdp->sd_jheightsize;
173 max = sdp->sd_max_jheight;
174 } else {
175 arr = sdp->sd_heightsize;
176 max = sdp->sd_max_height;
177 }
178
179 for (height = 0; height < max; height++)
180 if (arr[height] >= size)
181 break;
182
183 return height;
184}
185
186/**
187 * build_height - Build a metadata tree of the requested height
188 * @ip: The GFS2 inode
189 * @height: The height to build to
190 *
191 * This routine makes sure that the metadata tree is tall enough to hold
192 * "size" bytes of data.
193 *
194 * Returns: errno
195 */
196
197static int build_height(struct gfs2_inode *ip, int height)
198{
199 struct gfs2_sbd *sdp = ip->i_sbd;
200 struct buffer_head *bh, *dibh;
201 uint64_t block = 0, *bp;
202 unsigned int x;
203 int new_block;
204 int error;
205
206 while (ip->i_di.di_height < height) {
207 error = gfs2_meta_inode_buffer(ip, &dibh);
208 if (error)
209 return error;
210
211 new_block = 0;
212 bp = (uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode));
213 for (x = 0; x < sdp->sd_diptrs; x++, bp++)
214 if (*bp) {
215 new_block = 1;
216 break;
217 }
218
219 if (new_block) {
220 /* Get a new block, fill it with the old direct
221 pointers, and write it out */
222
223 block = gfs2_alloc_meta(ip);
224
225 bh = gfs2_meta_new(ip->i_gl, block);
226 gfs2_trans_add_bh(ip->i_gl, bh);
227 gfs2_metatype_set(bh,
228 GFS2_METATYPE_IN,
229 GFS2_FORMAT_IN);
230 gfs2_buffer_copy_tail(bh,
231 sizeof(struct gfs2_meta_header),
232 dibh, sizeof(struct gfs2_dinode));
233
234 brelse(bh);
235 }
236
237 /* Set up the new direct pointer and write it out to disk */
238
239 gfs2_trans_add_bh(ip->i_gl, dibh);
240
241 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
242
243 if (new_block) {
244 *(uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode)) = cpu_to_be64(block);
245 ip->i_di.di_blocks++;
246 }
247
248 ip->i_di.di_height++;
249
250 gfs2_dinode_out(&ip->i_di, dibh->b_data);
251 brelse(dibh);
252 }
253
254 return 0;
255}
256
257/**
258 * find_metapath - Find path through the metadata tree
259 * @ip: The inode pointer
260 * @mp: The metapath to return the result in
261 * @block: The disk block to look up
262 *
263 * This routine returns a struct metapath structure that defines a path
264 * through the metadata of inode "ip" to get to block "block".
265 *
266 * Example:
267 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a
268 * filesystem with a blocksize of 4096.
269 *
270 * find_metapath() would return a struct metapath structure set to:
271 * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48,
272 * and mp_list[2] = 165.
273 *
274 * That means that in order to get to the block containing the byte at
275 * offset 101342453, we would load the indirect block pointed to by pointer
276 * 0 in the dinode. We would then load the indirect block pointed to by
277 * pointer 48 in that indirect block. We would then load the data block
278 * pointed to by pointer 165 in that indirect block.
279 *
280 * ----------------------------------------
281 * | Dinode | |
282 * | | 4|
283 * | |0 1 2 3 4 5 9|
284 * | | 6|
285 * ----------------------------------------
286 * |
287 * |
288 * V
289 * ----------------------------------------
290 * | Indirect Block |
291 * | 5|
292 * | 4 4 4 4 4 5 5 1|
293 * |0 5 6 7 8 9 0 1 2|
294 * ----------------------------------------
295 * |
296 * |
297 * V
298 * ----------------------------------------
299 * | Indirect Block |
300 * | 1 1 1 1 1 5|
301 * | 6 6 6 6 6 1|
302 * |0 3 4 5 6 7 2|
303 * ----------------------------------------
304 * |
305 * |
306 * V
307 * ----------------------------------------
308 * | Data block containing offset |
309 * | 101342453 |
310 * | |
311 * | |
312 * ----------------------------------------
313 *
314 */
315
316static void find_metapath(struct gfs2_inode *ip, uint64_t block, struct metapath *mp)
317{
318 struct gfs2_sbd *sdp = ip->i_sbd;
319 uint64_t b = block;
320 unsigned int i;
321
322 for (i = ip->i_di.di_height; i--;)
323 mp->mp_list[i] = (__u16)do_div(b, sdp->sd_inptrs);
324
325}
326
327/**
328 * metapointer - Return pointer to start of metadata in a buffer
329 * @bh: The buffer
330 * @height: The metadata height (0 = dinode)
331 * @mp: The metapath
332 *
333 * Return a pointer to the block number of the next height of the metadata
334 * tree given a buffer containing the pointer to the current height of the
335 * metadata tree.
336 */
337
338static inline uint64_t *metapointer(struct buffer_head *bh,
339 unsigned int height, struct metapath *mp)
340{
341 unsigned int head_size = (height > 0) ?
342 sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode);
343
344 return ((uint64_t *)(bh->b_data + head_size)) + mp->mp_list[height];
345}
346
347/**
348 * lookup_block - Get the next metadata block in metadata tree
349 * @ip: The GFS2 inode
350 * @bh: Buffer containing the pointers to metadata blocks
351 * @height: The height of the tree (0 = dinode)
352 * @mp: The metapath
353 * @create: Non-zero if we may create a new meatdata block
354 * @new: Used to indicate if we did create a new metadata block
355 * @block: the returned disk block number
356 *
357 * Given a metatree, complete to a particular height, checks to see if the next
358 * height of the tree exists. If not the next height of the tree is created.
359 * The block number of the next height of the metadata tree is returned.
360 *
361 */
362
363static void lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
364 unsigned int height, struct metapath *mp, int create,
365 int *new, uint64_t *block)
366{
367 uint64_t *ptr = metapointer(bh, height, mp);
368
369 if (*ptr) {
370 *block = be64_to_cpu(*ptr);
371 return;
372 }
373
374 *block = 0;
375
376 if (!create)
377 return;
378
379 if (height == ip->i_di.di_height - 1 &&
380 !gfs2_is_jdata(ip))
381 *block = gfs2_alloc_data(ip);
382 else
383 *block = gfs2_alloc_meta(ip);
384
385 gfs2_trans_add_bh(ip->i_gl, bh);
386
387 *ptr = cpu_to_be64(*block);
388 ip->i_di.di_blocks++;
389
390 *new = 1;
391}
392
393/**
394 * gfs2_block_map - Map a block from an inode to a disk block
395 * @ip: The GFS2 inode
396 * @lblock: The logical block number
397 * @new: Value/Result argument (1 = may create/did create new blocks)
398 * @dblock: the disk block number of the start of an extent
399 * @extlen: the size of the extent
400 *
401 * Find the block number on the current device which corresponds to an
402 * inode's block. If the block had to be created, "new" will be set.
403 *
404 * Returns: errno
405 */
406
407int gfs2_block_map(struct gfs2_inode *ip, uint64_t lblock, int *new,
408 uint64_t *dblock, uint32_t *extlen)
409{
410 struct gfs2_sbd *sdp = ip->i_sbd;
411 struct buffer_head *bh;
412 struct metapath mp;
413 int create = *new;
414 unsigned int bsize;
415 unsigned int height;
416 unsigned int end_of_metadata;
417 unsigned int x;
418 int error = 0;
419
420 *new = 0;
421 *dblock = 0;
422 if (extlen)
423 *extlen = 0;
424
425 if (create)
426 down_write(&ip->i_rw_mutex);
427 else
428 down_read(&ip->i_rw_mutex);
429
430 if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
431 goto out;
432
433 bsize = (gfs2_is_jdata(ip)) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
434
435 height = calc_tree_height(ip, (lblock + 1) * bsize);
436 if (ip->i_di.di_height < height) {
437 if (!create)
438 goto out;
439
440 error = build_height(ip, height);
441 if (error)
442 goto out;
443 }
444
445 find_metapath(ip, lblock, &mp);
446 end_of_metadata = ip->i_di.di_height - 1;
447
448 error = gfs2_meta_inode_buffer(ip, &bh);
449 if (error)
450 goto out;
451
452 for (x = 0; x < end_of_metadata; x++) {
453 lookup_block(ip, bh, x, &mp, create, new, dblock);
454 brelse(bh);
455 if (!*dblock)
456 goto out;
457
458 error = gfs2_meta_indirect_buffer(ip, x+1, *dblock, *new, &bh);
459 if (error)
460 goto out;
461 }
462
463 lookup_block(ip, bh, end_of_metadata, &mp, create, new, dblock);
464
465 if (extlen && *dblock) {
466 *extlen = 1;
467
468 if (!*new) {
469 uint64_t tmp_dblock;
470 int tmp_new;
471 unsigned int nptrs;
472
473 nptrs = (end_of_metadata) ? sdp->sd_inptrs :
474 sdp->sd_diptrs;
475
476 while (++mp.mp_list[end_of_metadata] < nptrs) {
477 lookup_block(ip, bh, end_of_metadata, &mp,
478 0, &tmp_new, &tmp_dblock);
479
480 if (*dblock + *extlen != tmp_dblock)
481 break;
482
483 (*extlen)++;
484 }
485 }
486 }
487
488 brelse(bh);
489
490 if (*new) {
491 error = gfs2_meta_inode_buffer(ip, &bh);
492 if (!error) {
493 gfs2_trans_add_bh(ip->i_gl, bh);
494 gfs2_dinode_out(&ip->i_di, bh->b_data);
495 brelse(bh);
496 }
497 }
498
499 out:
500 if (create)
501 up_write(&ip->i_rw_mutex);
502 else
503 up_read(&ip->i_rw_mutex);
504
505 return error;
506}
507
508/**
509 * recursive_scan - recursively scan through the end of a file
510 * @ip: the inode
511 * @dibh: the dinode buffer
512 * @mp: the path through the metadata to the point to start
513 * @height: the height the recursion is at
514 * @block: the indirect block to look at
515 * @first: 1 if this is the first block
516 * @bc: the call to make for each piece of metadata
517 * @data: data opaque to this function to pass to @bc
518 *
519 * When this is first called @height and @block should be zero and
520 * @first should be 1.
521 *
522 * Returns: errno
523 */
524
525static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh,
526 struct metapath *mp, unsigned int height,
527 uint64_t block, int first, block_call_t bc,
528 void *data)
529{
530 struct gfs2_sbd *sdp = ip->i_sbd;
531 struct buffer_head *bh = NULL;
532 uint64_t *top, *bottom;
533 uint64_t bn;
534 int error;
535 int mh_size = sizeof(struct gfs2_meta_header);
536
537 if (!height) {
538 error = gfs2_meta_inode_buffer(ip, &bh);
539 if (error)
540 return error;
541 dibh = bh;
542
543 top = (uint64_t *)(bh->b_data + sizeof(struct gfs2_dinode)) +
544 mp->mp_list[0];
545 bottom = (uint64_t *)(bh->b_data + sizeof(struct gfs2_dinode)) +
546 sdp->sd_diptrs;
547 } else {
548 error = gfs2_meta_indirect_buffer(ip, height, block, 0, &bh);
549 if (error)
550 return error;
551
552 top = (uint64_t *)(bh->b_data + mh_size) +
553 ((first) ? mp->mp_list[height] : 0);
554
555 bottom = (uint64_t *)(bh->b_data + mh_size) + sdp->sd_inptrs;
556 }
557
558 error = bc(ip, dibh, bh, top, bottom, height, data);
559 if (error)
560 goto out;
561
562 if (height < ip->i_di.di_height - 1)
563 for (; top < bottom; top++, first = 0) {
564 if (!*top)
565 continue;
566
567 bn = be64_to_cpu(*top);
568
569 error = recursive_scan(ip, dibh, mp, height + 1, bn,
570 first, bc, data);
571 if (error)
572 break;
573 }
574
575 out:
576 brelse(bh);
577
578 return error;
579}
580
581/**
582 * do_strip - Look for a layer a particular layer of the file and strip it off
583 * @ip: the inode
584 * @dibh: the dinode buffer
585 * @bh: A buffer of pointers
586 * @top: The first pointer in the buffer
587 * @bottom: One more than the last pointer
588 * @height: the height this buffer is at
589 * @data: a pointer to a struct strip_mine
590 *
591 * Returns: errno
592 */
593
594static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
595 struct buffer_head *bh, uint64_t *top, uint64_t *bottom,
596 unsigned int height, void *data)
597{
598 struct strip_mine *sm = (struct strip_mine *)data;
599 struct gfs2_sbd *sdp = ip->i_sbd;
600 struct gfs2_rgrp_list rlist;
601 uint64_t bn, bstart;
602 uint32_t blen;
603 uint64_t *p;
604 unsigned int rg_blocks = 0;
605 int metadata;
606 unsigned int revokes = 0;
607 int x;
608 int error;
609
610 if (!*top)
611 sm->sm_first = 0;
612
613 if (height != sm->sm_height)
614 return 0;
615
616 if (sm->sm_first) {
617 top++;
618 sm->sm_first = 0;
619 }
620
621 metadata = (height != ip->i_di.di_height - 1) || gfs2_is_jdata(ip);
622 if (metadata)
623 revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs;
624
625 error = gfs2_rindex_hold(sdp, &ip->i_alloc.al_ri_gh);
626 if (error)
627 return error;
628
629 memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
630 bstart = 0;
631 blen = 0;
632
633 for (p = top; p < bottom; p++) {
634 if (!*p)
635 continue;
636
637 bn = be64_to_cpu(*p);
638
639 if (bstart + blen == bn)
640 blen++;
641 else {
642 if (bstart)
643 gfs2_rlist_add(sdp, &rlist, bstart);
644
645 bstart = bn;
646 blen = 1;
647 }
648 }
649
650 if (bstart)
651 gfs2_rlist_add(sdp, &rlist, bstart);
652 else
653 goto out; /* Nothing to do */
654
655 gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0);
656
657 for (x = 0; x < rlist.rl_rgrps; x++) {
658 struct gfs2_rgrpd *rgd;
659 rgd = get_gl2rgd(rlist.rl_ghs[x].gh_gl);
660 rg_blocks += rgd->rd_ri.ri_length;
661 }
662
663 error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
664 if (error)
665 goto out_rlist;
666
667 error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE +
668 RES_INDIRECT + RES_STATFS + RES_QUOTA,
669 revokes);
670 if (error)
671 goto out_rg_gunlock;
672
673 down_write(&ip->i_rw_mutex);
674
675 gfs2_trans_add_bh(ip->i_gl, dibh);
676 gfs2_trans_add_bh(ip->i_gl, bh);
677
678 bstart = 0;
679 blen = 0;
680
681 for (p = top; p < bottom; p++) {
682 if (!*p)
683 continue;
684
685 bn = be64_to_cpu(*p);
686
687 if (bstart + blen == bn)
688 blen++;
689 else {
690 if (bstart) {
691 if (metadata)
692 gfs2_free_meta(ip, bstart, blen);
693 else
694 gfs2_free_data(ip, bstart, blen);
695 }
696
697 bstart = bn;
698 blen = 1;
699 }
700
701 *p = 0;
702 if (!ip->i_di.di_blocks)
703 gfs2_consist_inode(ip);
704 ip->i_di.di_blocks--;
705 }
706 if (bstart) {
707 if (metadata)
708 gfs2_free_meta(ip, bstart, blen);
709 else
710 gfs2_free_data(ip, bstart, blen);
711 }
712
713 ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
714
715 gfs2_dinode_out(&ip->i_di, dibh->b_data);
716
717 up_write(&ip->i_rw_mutex);
718
719 gfs2_trans_end(sdp);
720
721 out_rg_gunlock:
722 gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
723
724 out_rlist:
725 gfs2_rlist_free(&rlist);
726
727 out:
728 gfs2_glock_dq_uninit(&ip->i_alloc.al_ri_gh);
729
730 return error;
731}
732
733/**
734 * do_grow - Make a file look bigger than it is
735 * @ip: the inode
736 * @size: the size to set the file to
737 *
738 * Called with an exclusive lock on @ip.
739 *
740 * Returns: errno
741 */
742
743static int do_grow(struct gfs2_inode *ip, uint64_t size)
744{
745 struct gfs2_sbd *sdp = ip->i_sbd;
746 struct gfs2_alloc *al;
747 struct buffer_head *dibh;
748 unsigned int h;
749 int error;
750
751 al = gfs2_alloc_get(ip);
752
753 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
754 if (error)
755 goto out;
756
757 error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
758 if (error)
759 goto out_gunlock_q;
760
761 al->al_requested = sdp->sd_max_height + RES_DATA;
762
763 error = gfs2_inplace_reserve(ip);
764 if (error)
765 goto out_gunlock_q;
766
767 error = gfs2_trans_begin(sdp,
768 sdp->sd_max_height + al->al_rgd->rd_ri.ri_length +
769 RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0);
770 if (error)
771 goto out_ipres;
772
773 if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
774 if (gfs2_is_stuffed(ip)) {
775 error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
776 NULL);
777 if (error)
778 goto out_end_trans;
779 }
780
781 h = calc_tree_height(ip, size);
782 if (ip->i_di.di_height < h) {
783 down_write(&ip->i_rw_mutex);
784 error = build_height(ip, h);
785 up_write(&ip->i_rw_mutex);
786 if (error)
787 goto out_end_trans;
788 }
789 }
790
791 ip->i_di.di_size = size;
792 ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
793
794 error = gfs2_meta_inode_buffer(ip, &dibh);
795 if (error)
796 goto out_end_trans;
797
798 gfs2_trans_add_bh(ip->i_gl, dibh);
799 gfs2_dinode_out(&ip->i_di, dibh->b_data);
800 brelse(dibh);
801
802 out_end_trans:
803 gfs2_trans_end(sdp);
804
805 out_ipres:
806 gfs2_inplace_release(ip);
807
808 out_gunlock_q:
809 gfs2_quota_unlock(ip);
810
811 out:
812 gfs2_alloc_put(ip);
813
814 return error;
815}
816
817static int truncator_journaled(struct gfs2_inode *ip, uint64_t size)
818{
819 uint64_t lbn, dbn;
820 uint32_t off;
821 struct buffer_head *bh;
822 int new = 0;
823 int error;
824
825 lbn = size;
826 off = do_div(lbn, ip->i_sbd->sd_jbsize);
827
828 error = gfs2_block_map(ip, lbn, &new, &dbn, NULL);
829 if (error || !dbn)
830 return error;
831
832 error = gfs2_jdata_get_buffer(ip, dbn, 0, &bh);
833 if (error)
834 return error;
835
836 gfs2_trans_add_bh(ip->i_gl, bh);
837 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header) + off);
838
839 brelse(bh);
840
841 return 0;
842}
843
844static int trunc_start(struct gfs2_inode *ip, uint64_t size,
845 gfs2_truncator_t truncator)
846{
847 struct gfs2_sbd *sdp = ip->i_sbd;
848 struct buffer_head *dibh;
849 int journaled = gfs2_is_jdata(ip);
850 int error;
851
852 error = gfs2_trans_begin(sdp,
853 RES_DINODE + ((journaled) ? RES_JDATA : 0), 0);
854 if (error)
855 return error;
856
857 error = gfs2_meta_inode_buffer(ip, &dibh);
858 if (error)
859 goto out;
860
861 if (gfs2_is_stuffed(ip)) {
862 ip->i_di.di_size = size;
863 ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
864 gfs2_trans_add_bh(ip->i_gl, dibh);
865 gfs2_dinode_out(&ip->i_di, dibh->b_data);
866 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size);
867 error = 1;
868
869 } else {
870 if (journaled) {
871 uint64_t junk = size;
872 /* we're just interested in the modulus */
873 if (do_div(junk, sdp->sd_jbsize))
874 error = truncator_journaled(ip, size);
875 } else if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1))
876 error = truncator(ip, size);
877
878 if (!error) {
879 ip->i_di.di_size = size;
880 ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
881 ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG;
882 gfs2_trans_add_bh(ip->i_gl, dibh);
883 gfs2_dinode_out(&ip->i_di, dibh->b_data);
884 }
885 }
886
887 brelse(dibh);
888
889 out:
890 gfs2_trans_end(sdp);
891
892 return error;
893}
894
895static int trunc_dealloc(struct gfs2_inode *ip, uint64_t size)
896{
897 unsigned int height = ip->i_di.di_height;
898 uint64_t lblock;
899 struct metapath mp;
900 int error;
901
902 if (!size)
903 lblock = 0;
904 else if (gfs2_is_jdata(ip)) {
905 lblock = size - 1;
906 do_div(lblock, ip->i_sbd->sd_jbsize);
907 } else
908 lblock = (size - 1) >> ip->i_sbd->sd_sb.sb_bsize_shift;
909
910 find_metapath(ip, lblock, &mp);
911 gfs2_alloc_get(ip);
912
913 error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
914 if (error)
915 goto out;
916
917 while (height--) {
918 struct strip_mine sm;
919 sm.sm_first = !!size;
920 sm.sm_height = height;
921
922 error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm);
923 if (error)
924 break;
925 }
926
927 gfs2_quota_unhold(ip);
928
929 out:
930 gfs2_alloc_put(ip);
931 return error;
932}
933
934static int trunc_end(struct gfs2_inode *ip)
935{
936 struct gfs2_sbd *sdp = ip->i_sbd;
937 struct buffer_head *dibh;
938 int error;
939
940 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
941 if (error)
942 return error;
943
944 down_write(&ip->i_rw_mutex);
945
946 error = gfs2_meta_inode_buffer(ip, &dibh);
947 if (error)
948 goto out;
949
950 if (!ip->i_di.di_size) {
951 ip->i_di.di_height = 0;
952 ip->i_di.di_goal_meta =
953 ip->i_di.di_goal_data =
954 ip->i_num.no_addr;
955 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
956 }
957 ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
958 ip->i_di.di_flags &= ~GFS2_DIF_TRUNC_IN_PROG;
959
960 gfs2_trans_add_bh(ip->i_gl, dibh);
961 gfs2_dinode_out(&ip->i_di, dibh->b_data);
962 brelse(dibh);
963
964 out:
965 up_write(&ip->i_rw_mutex);
966
967 gfs2_trans_end(sdp);
968
969 return error;
970}
971
972/**
973 * do_shrink - make a file smaller
974 * @ip: the inode
975 * @size: the size to make the file
976 * @truncator: function to truncate the last partial block
977 *
978 * Called with an exclusive lock on @ip.
979 *
980 * Returns: errno
981 */
982
983static int do_shrink(struct gfs2_inode *ip, uint64_t size,
984 gfs2_truncator_t truncator)
985{
986 int error;
987
988 error = trunc_start(ip, size, truncator);
989 if (error < 0)
990 return error;
991 if (error > 0)
992 return 0;
993
994 error = trunc_dealloc(ip, size);
995 if (!error)
996 error = trunc_end(ip);
997
998 return error;
999}
1000
1001/**
1002 * gfs2_truncatei - make a file a give size
1003 * @ip: the inode
1004 * @size: the size to make the file
1005 * @truncator: function to truncate the last partial block
1006 *
1007 * The file size can grow, shrink, or stay the same size.
1008 *
1009 * Returns: errno
1010 */
1011
1012int gfs2_truncatei(struct gfs2_inode *ip, uint64_t size,
1013 gfs2_truncator_t truncator)
1014{
1015 int error;
1016
1017 if (gfs2_assert_warn(ip->i_sbd, S_ISREG(ip->i_di.di_mode)))
1018 return -EINVAL;
1019
1020 if (size > ip->i_di.di_size)
1021 error = do_grow(ip, size);
1022 else
1023 error = do_shrink(ip, size, truncator);
1024
1025 return error;
1026}
1027
1028int gfs2_truncatei_resume(struct gfs2_inode *ip)
1029{
1030 int error;
1031 error = trunc_dealloc(ip, ip->i_di.di_size);
1032 if (!error)
1033 error = trunc_end(ip);
1034 return error;
1035}
1036
1037int gfs2_file_dealloc(struct gfs2_inode *ip)
1038{
1039 return trunc_dealloc(ip, 0);
1040}
1041
1042/**
1043 * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
1044 * @ip: the file
1045 * @len: the number of bytes to be written to the file
1046 * @data_blocks: returns the number of data blocks required
1047 * @ind_blocks: returns the number of indirect blocks required
1048 *
1049 */
1050
1051void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len,
1052 unsigned int *data_blocks, unsigned int *ind_blocks)
1053{
1054 struct gfs2_sbd *sdp = ip->i_sbd;
1055 unsigned int tmp;
1056
1057 if (gfs2_is_jdata(ip)) {
1058 *data_blocks = DIV_RU(len, sdp->sd_jbsize) + 2;
1059 *ind_blocks = 3 * (sdp->sd_max_jheight - 1);
1060 } else {
1061 *data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3;
1062 *ind_blocks = 3 * (sdp->sd_max_height - 1);
1063 }
1064
1065 for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) {
1066 tmp = DIV_RU(tmp, sdp->sd_inptrs);
1067 *ind_blocks += tmp;
1068 }
1069}
1070
1071/**
1072 * gfs2_write_alloc_required - figure out if a write will require an allocation
1073 * @ip: the file being written to
1074 * @offset: the offset to write to
1075 * @len: the number of bytes being written
1076 * @alloc_required: set to 1 if an alloc is required, 0 otherwise
1077 *
1078 * Returns: errno
1079 */
1080
1081int gfs2_write_alloc_required(struct gfs2_inode *ip, uint64_t offset,
1082 unsigned int len, int *alloc_required)
1083{
1084 struct gfs2_sbd *sdp = ip->i_sbd;
1085 uint64_t lblock, lblock_stop, dblock;
1086 uint32_t extlen;
1087 int new = 0;
1088 int error = 0;
1089
1090 *alloc_required = 0;
1091
1092 if (!len)
1093 return 0;
1094
1095 if (gfs2_is_stuffed(ip)) {
1096 if (offset + len >
1097 sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
1098 *alloc_required = 1;
1099 return 0;
1100 }
1101
1102 if (gfs2_is_jdata(ip)) {
1103 unsigned int bsize = sdp->sd_jbsize;
1104 lblock = offset;
1105 do_div(lblock, bsize);
1106 lblock_stop = offset + len + bsize - 1;
1107 do_div(lblock_stop, bsize);
1108 } else {
1109 unsigned int shift = sdp->sd_sb.sb_bsize_shift;
1110 lblock = offset >> shift;
1111 lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
1112 }
1113
1114 for (; lblock < lblock_stop; lblock += extlen) {
1115 error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
1116 if (error)
1117 return error;
1118
1119 if (!dblock) {
1120 *alloc_required = 1;
1121 return 0;
1122 }
1123 }
1124
1125 return 0;
1126}
1127
1128/**
1129 * do_gfm - Copy out the dinode/indirect blocks of a file
1130 * @ip: the file
1131 * @dibh: the dinode buffer
1132 * @bh: the indirect buffer we're looking at
1133 * @top: the first pointer in the block
1134 * @bottom: one more than the last pointer in the block
1135 * @height: the height the block is at
1136 * @data: a pointer to a struct gfs2_user_buffer structure
1137 *
1138 * If this is a journaled file, copy out the data too.
1139 *
1140 * Returns: errno
1141 */
1142
1143static int do_gfm(struct gfs2_inode *ip, struct buffer_head *dibh,
1144 struct buffer_head *bh, uint64_t *top, uint64_t *bottom,
1145 unsigned int height, void *data)
1146{
1147 struct gfs2_user_buffer *ub = (struct gfs2_user_buffer *)data;
1148 int error;
1149
1150 error = gfs2_add_bh_to_ub(ub, bh);
1151 if (error)
1152 return error;
1153
1154 if (!S_ISDIR(ip->i_di.di_mode) ||
1155 height + 1 != ip->i_di.di_height)
1156 return 0;
1157
1158 for (; top < bottom; top++)
1159 if (*top) {
1160 struct buffer_head *data_bh;
1161
1162 error = gfs2_meta_read(ip->i_gl, be64_to_cpu(*top),
1163 DIO_START | DIO_WAIT,
1164 &data_bh);
1165 if (error)
1166 return error;
1167
1168 error = gfs2_add_bh_to_ub(ub, data_bh);
1169
1170 brelse(data_bh);
1171
1172 if (error)
1173 return error;
1174 }
1175
1176 return 0;
1177}
1178
1179/**
1180 * gfs2_get_file_meta - return all the metadata for a file
1181 * @ip: the file
1182 * @ub: the structure representing the meta
1183 *
1184 * Returns: errno
1185 */
1186
1187int gfs2_get_file_meta(struct gfs2_inode *ip, struct gfs2_user_buffer *ub)
1188{
1189 int error;
1190
1191 if (gfs2_is_stuffed(ip)) {
1192 struct buffer_head *dibh;
1193 error = gfs2_meta_inode_buffer(ip, &dibh);
1194 if (!error) {
1195 error = gfs2_add_bh_to_ub(ub, dibh);
1196 brelse(dibh);
1197 }
1198 } else {
1199 struct metapath mp;
1200 find_metapath(ip, 0, &mp);
1201 error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_gfm, ub);
1202 }
1203
1204 return error;
1205}
1206