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1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 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 version 2.
8 */
9
10#include <linux/spinlock.h>
11#include <linux/completion.h>
12#include <linux/buffer_head.h>
13#include <linux/blkdev.h>
14#include <linux/gfs2_ondisk.h>
15#include <linux/crc32.h>
16
17#include "gfs2.h"
18#include "incore.h"
19#include "bmap.h"
20#include "glock.h"
21#include "inode.h"
22#include "meta_io.h"
23#include "quota.h"
24#include "rgrp.h"
25#include "log.h"
26#include "super.h"
27#include "trans.h"
28#include "dir.h"
29#include "util.h"
30#include "trace_gfs2.h"
31
32/* This doesn't need to be that large as max 64 bit pointers in a 4k
33 * block is 512, so __u16 is fine for that. It saves stack space to
34 * keep it small.
35 */
36struct metapath {
37 struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT];
38 __u16 mp_list[GFS2_MAX_META_HEIGHT];
39};
40
41struct strip_mine {
42 int sm_first;
43 unsigned int sm_height;
44};
45
46/**
47 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
48 * @ip: the inode
49 * @dibh: the dinode buffer
50 * @block: the block number that was allocated
51 * @page: The (optional) page. This is looked up if @page is NULL
52 *
53 * Returns: errno
54 */
55
56static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
57 u64 block, struct page *page)
58{
59 struct inode *inode = &ip->i_inode;
60 struct buffer_head *bh;
61 int release = 0;
62
63 if (!page || page->index) {
64 page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS);
65 if (!page)
66 return -ENOMEM;
67 release = 1;
68 }
69
70 if (!PageUptodate(page)) {
71 void *kaddr = kmap(page);
72 u64 dsize = i_size_read(inode);
73
74 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
75 dsize = dibh->b_size - sizeof(struct gfs2_dinode);
76
77 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
78 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
79 kunmap(page);
80
81 SetPageUptodate(page);
82 }
83
84 if (!page_has_buffers(page))
85 create_empty_buffers(page, 1 << inode->i_blkbits,
86 (1 << BH_Uptodate));
87
88 bh = page_buffers(page);
89
90 if (!buffer_mapped(bh))
91 map_bh(bh, inode->i_sb, block);
92
93 set_buffer_uptodate(bh);
94 if (!gfs2_is_jdata(ip))
95 mark_buffer_dirty(bh);
96 if (!gfs2_is_writeback(ip))
97 gfs2_trans_add_data(ip->i_gl, bh);
98
99 if (release) {
100 unlock_page(page);
101 page_cache_release(page);
102 }
103
104 return 0;
105}
106
107/**
108 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
109 * @ip: The GFS2 inode to unstuff
110 * @page: The (optional) page. This is looked up if the @page is NULL
111 *
112 * This routine unstuffs a dinode and returns it to a "normal" state such
113 * that the height can be grown in the traditional way.
114 *
115 * Returns: errno
116 */
117
118int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page)
119{
120 struct buffer_head *bh, *dibh;
121 struct gfs2_dinode *di;
122 u64 block = 0;
123 int isdir = gfs2_is_dir(ip);
124 int error;
125
126 down_write(&ip->i_rw_mutex);
127
128 error = gfs2_meta_inode_buffer(ip, &dibh);
129 if (error)
130 goto out;
131
132 if (i_size_read(&ip->i_inode)) {
133 /* Get a free block, fill it with the stuffed data,
134 and write it out to disk */
135
136 unsigned int n = 1;
137 error = gfs2_alloc_blocks(ip, &block, &n, 0, NULL);
138 if (error)
139 goto out_brelse;
140 if (isdir) {
141 gfs2_trans_add_unrevoke(GFS2_SB(&ip->i_inode), block, 1);
142 error = gfs2_dir_get_new_buffer(ip, block, &bh);
143 if (error)
144 goto out_brelse;
145 gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header),
146 dibh, sizeof(struct gfs2_dinode));
147 brelse(bh);
148 } else {
149 error = gfs2_unstuffer_page(ip, dibh, block, page);
150 if (error)
151 goto out_brelse;
152 }
153 }
154
155 /* Set up the pointer to the new block */
156
157 gfs2_trans_add_meta(ip->i_gl, dibh);
158 di = (struct gfs2_dinode *)dibh->b_data;
159 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
160
161 if (i_size_read(&ip->i_inode)) {
162 *(__be64 *)(di + 1) = cpu_to_be64(block);
163 gfs2_add_inode_blocks(&ip->i_inode, 1);
164 di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
165 }
166
167 ip->i_height = 1;
168 di->di_height = cpu_to_be16(1);
169
170out_brelse:
171 brelse(dibh);
172out:
173 up_write(&ip->i_rw_mutex);
174 return error;
175}
176
177
178/**
179 * find_metapath - Find path through the metadata tree
180 * @sdp: The superblock
181 * @mp: The metapath to return the result in
182 * @block: The disk block to look up
183 * @height: The pre-calculated height of the metadata tree
184 *
185 * This routine returns a struct metapath structure that defines a path
186 * through the metadata of inode "ip" to get to block "block".
187 *
188 * Example:
189 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a
190 * filesystem with a blocksize of 4096.
191 *
192 * find_metapath() would return a struct metapath structure set to:
193 * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48,
194 * and mp_list[2] = 165.
195 *
196 * That means that in order to get to the block containing the byte at
197 * offset 101342453, we would load the indirect block pointed to by pointer
198 * 0 in the dinode. We would then load the indirect block pointed to by
199 * pointer 48 in that indirect block. We would then load the data block
200 * pointed to by pointer 165 in that indirect block.
201 *
202 * ----------------------------------------
203 * | Dinode | |
204 * | | 4|
205 * | |0 1 2 3 4 5 9|
206 * | | 6|
207 * ----------------------------------------
208 * |
209 * |
210 * V
211 * ----------------------------------------
212 * | Indirect Block |
213 * | 5|
214 * | 4 4 4 4 4 5 5 1|
215 * |0 5 6 7 8 9 0 1 2|
216 * ----------------------------------------
217 * |
218 * |
219 * V
220 * ----------------------------------------
221 * | Indirect Block |
222 * | 1 1 1 1 1 5|
223 * | 6 6 6 6 6 1|
224 * |0 3 4 5 6 7 2|
225 * ----------------------------------------
226 * |
227 * |
228 * V
229 * ----------------------------------------
230 * | Data block containing offset |
231 * | 101342453 |
232 * | |
233 * | |
234 * ----------------------------------------
235 *
236 */
237
238static void find_metapath(const struct gfs2_sbd *sdp, u64 block,
239 struct metapath *mp, unsigned int height)
240{
241 unsigned int i;
242
243 for (i = height; i--;)
244 mp->mp_list[i] = do_div(block, sdp->sd_inptrs);
245
246}
247
248static inline unsigned int metapath_branch_start(const struct metapath *mp)
249{
250 if (mp->mp_list[0] == 0)
251 return 2;
252 return 1;
253}
254
255/**
256 * metapointer - Return pointer to start of metadata in a buffer
257 * @height: The metadata height (0 = dinode)
258 * @mp: The metapath
259 *
260 * Return a pointer to the block number of the next height of the metadata
261 * tree given a buffer containing the pointer to the current height of the
262 * metadata tree.
263 */
264
265static inline __be64 *metapointer(unsigned int height, const struct metapath *mp)
266{
267 struct buffer_head *bh = mp->mp_bh[height];
268 unsigned int head_size = (height > 0) ?
269 sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode);
270 return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height];
271}
272
273static void gfs2_metapath_ra(struct gfs2_glock *gl,
274 const struct buffer_head *bh, const __be64 *pos)
275{
276 struct buffer_head *rabh;
277 const __be64 *endp = (const __be64 *)(bh->b_data + bh->b_size);
278 const __be64 *t;
279
280 for (t = pos; t < endp; t++) {
281 if (!*t)
282 continue;
283
284 rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE);
285 if (trylock_buffer(rabh)) {
286 if (!buffer_uptodate(rabh)) {
287 rabh->b_end_io = end_buffer_read_sync;
288 submit_bh(READA | REQ_META, rabh);
289 continue;
290 }
291 unlock_buffer(rabh);
292 }
293 brelse(rabh);
294 }
295}
296
297/**
298 * lookup_metapath - Walk the metadata tree to a specific point
299 * @ip: The inode
300 * @mp: The metapath
301 *
302 * Assumes that the inode's buffer has already been looked up and
303 * hooked onto mp->mp_bh[0] and that the metapath has been initialised
304 * by find_metapath().
305 *
306 * If this function encounters part of the tree which has not been
307 * allocated, it returns the current height of the tree at the point
308 * at which it found the unallocated block. Blocks which are found are
309 * added to the mp->mp_bh[] list.
310 *
311 * Returns: error or height of metadata tree
312 */
313
314static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
315{
316 unsigned int end_of_metadata = ip->i_height - 1;
317 unsigned int x;
318 __be64 *ptr;
319 u64 dblock;
320 int ret;
321
322 for (x = 0; x < end_of_metadata; x++) {
323 ptr = metapointer(x, mp);
324 dblock = be64_to_cpu(*ptr);
325 if (!dblock)
326 return x + 1;
327
328 ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, &mp->mp_bh[x+1]);
329 if (ret)
330 return ret;
331 }
332
333 return ip->i_height;
334}
335
336static inline void release_metapath(struct metapath *mp)
337{
338 int i;
339
340 for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) {
341 if (mp->mp_bh[i] == NULL)
342 break;
343 brelse(mp->mp_bh[i]);
344 }
345}
346
347/**
348 * gfs2_extent_length - Returns length of an extent of blocks
349 * @start: Start of the buffer
350 * @len: Length of the buffer in bytes
351 * @ptr: Current position in the buffer
352 * @limit: Max extent length to return (0 = unlimited)
353 * @eob: Set to 1 if we hit "end of block"
354 *
355 * If the first block is zero (unallocated) it will return the number of
356 * unallocated blocks in the extent, otherwise it will return the number
357 * of contiguous blocks in the extent.
358 *
359 * Returns: The length of the extent (minimum of one block)
360 */
361
362static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, unsigned limit, int *eob)
363{
364 const __be64 *end = (start + len);
365 const __be64 *first = ptr;
366 u64 d = be64_to_cpu(*ptr);
367
368 *eob = 0;
369 do {
370 ptr++;
371 if (ptr >= end)
372 break;
373 if (limit && --limit == 0)
374 break;
375 if (d)
376 d++;
377 } while(be64_to_cpu(*ptr) == d);
378 if (ptr >= end)
379 *eob = 1;
380 return (ptr - first);
381}
382
383static inline void bmap_lock(struct gfs2_inode *ip, int create)
384{
385 if (create)
386 down_write(&ip->i_rw_mutex);
387 else
388 down_read(&ip->i_rw_mutex);
389}
390
391static inline void bmap_unlock(struct gfs2_inode *ip, int create)
392{
393 if (create)
394 up_write(&ip->i_rw_mutex);
395 else
396 up_read(&ip->i_rw_mutex);
397}
398
399static inline __be64 *gfs2_indirect_init(struct metapath *mp,
400 struct gfs2_glock *gl, unsigned int i,
401 unsigned offset, u64 bn)
402{
403 __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data +
404 ((i > 1) ? sizeof(struct gfs2_meta_header) :
405 sizeof(struct gfs2_dinode)));
406 BUG_ON(i < 1);
407 BUG_ON(mp->mp_bh[i] != NULL);
408 mp->mp_bh[i] = gfs2_meta_new(gl, bn);
409 gfs2_trans_add_meta(gl, mp->mp_bh[i]);
410 gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN);
411 gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header));
412 ptr += offset;
413 *ptr = cpu_to_be64(bn);
414 return ptr;
415}
416
417enum alloc_state {
418 ALLOC_DATA = 0,
419 ALLOC_GROW_DEPTH = 1,
420 ALLOC_GROW_HEIGHT = 2,
421 /* ALLOC_UNSTUFF = 3, TBD and rather complicated */
422};
423
424/**
425 * gfs2_bmap_alloc - Build a metadata tree of the requested height
426 * @inode: The GFS2 inode
427 * @lblock: The logical starting block of the extent
428 * @bh_map: This is used to return the mapping details
429 * @mp: The metapath
430 * @sheight: The starting height (i.e. whats already mapped)
431 * @height: The height to build to
432 * @maxlen: The max number of data blocks to alloc
433 *
434 * In this routine we may have to alloc:
435 * i) Indirect blocks to grow the metadata tree height
436 * ii) Indirect blocks to fill in lower part of the metadata tree
437 * iii) Data blocks
438 *
439 * The function is in two parts. The first part works out the total
440 * number of blocks which we need. The second part does the actual
441 * allocation asking for an extent at a time (if enough contiguous free
442 * blocks are available, there will only be one request per bmap call)
443 * and uses the state machine to initialise the blocks in order.
444 *
445 * Returns: errno on error
446 */
447
448static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock,
449 struct buffer_head *bh_map, struct metapath *mp,
450 const unsigned int sheight,
451 const unsigned int height,
452 const unsigned int maxlen)
453{
454 struct gfs2_inode *ip = GFS2_I(inode);
455 struct gfs2_sbd *sdp = GFS2_SB(inode);
456 struct super_block *sb = sdp->sd_vfs;
457 struct buffer_head *dibh = mp->mp_bh[0];
458 u64 bn, dblock = 0;
459 unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0;
460 unsigned dblks = 0;
461 unsigned ptrs_per_blk;
462 const unsigned end_of_metadata = height - 1;
463 int ret;
464 int eob = 0;
465 enum alloc_state state;
466 __be64 *ptr;
467 __be64 zero_bn = 0;
468
469 BUG_ON(sheight < 1);
470 BUG_ON(dibh == NULL);
471
472 gfs2_trans_add_meta(ip->i_gl, dibh);
473
474 if (height == sheight) {
475 struct buffer_head *bh;
476 /* Bottom indirect block exists, find unalloced extent size */
477 ptr = metapointer(end_of_metadata, mp);
478 bh = mp->mp_bh[end_of_metadata];
479 dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen,
480 &eob);
481 BUG_ON(dblks < 1);
482 state = ALLOC_DATA;
483 } else {
484 /* Need to allocate indirect blocks */
485 ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs;
486 dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]);
487 if (height == ip->i_height) {
488 /* Writing into existing tree, extend tree down */
489 iblks = height - sheight;
490 state = ALLOC_GROW_DEPTH;
491 } else {
492 /* Building up tree height */
493 state = ALLOC_GROW_HEIGHT;
494 iblks = height - ip->i_height;
495 branch_start = metapath_branch_start(mp);
496 iblks += (height - branch_start);
497 }
498 }
499
500 /* start of the second part of the function (state machine) */
501
502 blks = dblks + iblks;
503 i = sheight;
504 do {
505 int error;
506 n = blks - alloced;
507 error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
508 if (error)
509 return error;
510 alloced += n;
511 if (state != ALLOC_DATA || gfs2_is_jdata(ip))
512 gfs2_trans_add_unrevoke(sdp, bn, n);
513 switch (state) {
514 /* Growing height of tree */
515 case ALLOC_GROW_HEIGHT:
516 if (i == 1) {
517 ptr = (__be64 *)(dibh->b_data +
518 sizeof(struct gfs2_dinode));
519 zero_bn = *ptr;
520 }
521 for (; i - 1 < height - ip->i_height && n > 0; i++, n--)
522 gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++);
523 if (i - 1 == height - ip->i_height) {
524 i--;
525 gfs2_buffer_copy_tail(mp->mp_bh[i],
526 sizeof(struct gfs2_meta_header),
527 dibh, sizeof(struct gfs2_dinode));
528 gfs2_buffer_clear_tail(dibh,
529 sizeof(struct gfs2_dinode) +
530 sizeof(__be64));
531 ptr = (__be64 *)(mp->mp_bh[i]->b_data +
532 sizeof(struct gfs2_meta_header));
533 *ptr = zero_bn;
534 state = ALLOC_GROW_DEPTH;
535 for(i = branch_start; i < height; i++) {
536 if (mp->mp_bh[i] == NULL)
537 break;
538 brelse(mp->mp_bh[i]);
539 mp->mp_bh[i] = NULL;
540 }
541 i = branch_start;
542 }
543 if (n == 0)
544 break;
545 /* Branching from existing tree */
546 case ALLOC_GROW_DEPTH:
547 if (i > 1 && i < height)
548 gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[i-1]);
549 for (; i < height && n > 0; i++, n--)
550 gfs2_indirect_init(mp, ip->i_gl, i,
551 mp->mp_list[i-1], bn++);
552 if (i == height)
553 state = ALLOC_DATA;
554 if (n == 0)
555 break;
556 /* Tree complete, adding data blocks */
557 case ALLOC_DATA:
558 BUG_ON(n > dblks);
559 BUG_ON(mp->mp_bh[end_of_metadata] == NULL);
560 gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[end_of_metadata]);
561 dblks = n;
562 ptr = metapointer(end_of_metadata, mp);
563 dblock = bn;
564 while (n-- > 0)
565 *ptr++ = cpu_to_be64(bn++);
566 if (buffer_zeronew(bh_map)) {
567 ret = sb_issue_zeroout(sb, dblock, dblks,
568 GFP_NOFS);
569 if (ret) {
570 fs_err(sdp,
571 "Failed to zero data buffers\n");
572 clear_buffer_zeronew(bh_map);
573 }
574 }
575 break;
576 }
577 } while ((state != ALLOC_DATA) || !dblock);
578
579 ip->i_height = height;
580 gfs2_add_inode_blocks(&ip->i_inode, alloced);
581 gfs2_dinode_out(ip, mp->mp_bh[0]->b_data);
582 map_bh(bh_map, inode->i_sb, dblock);
583 bh_map->b_size = dblks << inode->i_blkbits;
584 set_buffer_new(bh_map);
585 return 0;
586}
587
588/**
589 * gfs2_block_map - Map a block from an inode to a disk block
590 * @inode: The inode
591 * @lblock: The logical block number
592 * @bh_map: The bh to be mapped
593 * @create: True if its ok to alloc blocks to satify the request
594 *
595 * Sets buffer_mapped() if successful, sets buffer_boundary() if a
596 * read of metadata will be required before the next block can be
597 * mapped. Sets buffer_new() if new blocks were allocated.
598 *
599 * Returns: errno
600 */
601
602int gfs2_block_map(struct inode *inode, sector_t lblock,
603 struct buffer_head *bh_map, int create)
604{
605 struct gfs2_inode *ip = GFS2_I(inode);
606 struct gfs2_sbd *sdp = GFS2_SB(inode);
607 unsigned int bsize = sdp->sd_sb.sb_bsize;
608 const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits;
609 const u64 *arr = sdp->sd_heightsize;
610 __be64 *ptr;
611 u64 size;
612 struct metapath mp;
613 int ret;
614 int eob;
615 unsigned int len;
616 struct buffer_head *bh;
617 u8 height;
618
619 BUG_ON(maxlen == 0);
620
621 memset(mp.mp_bh, 0, sizeof(mp.mp_bh));
622 bmap_lock(ip, create);
623 clear_buffer_mapped(bh_map);
624 clear_buffer_new(bh_map);
625 clear_buffer_boundary(bh_map);
626 trace_gfs2_bmap(ip, bh_map, lblock, create, 1);
627 if (gfs2_is_dir(ip)) {
628 bsize = sdp->sd_jbsize;
629 arr = sdp->sd_jheightsize;
630 }
631
632 ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
633 if (ret)
634 goto out;
635
636 height = ip->i_height;
637 size = (lblock + 1) * bsize;
638 while (size > arr[height])
639 height++;
640 find_metapath(sdp, lblock, &mp, height);
641 ret = 1;
642 if (height > ip->i_height || gfs2_is_stuffed(ip))
643 goto do_alloc;
644 ret = lookup_metapath(ip, &mp);
645 if (ret < 0)
646 goto out;
647 if (ret != ip->i_height)
648 goto do_alloc;
649 ptr = metapointer(ip->i_height - 1, &mp);
650 if (*ptr == 0)
651 goto do_alloc;
652 map_bh(bh_map, inode->i_sb, be64_to_cpu(*ptr));
653 bh = mp.mp_bh[ip->i_height - 1];
654 len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, &eob);
655 bh_map->b_size = (len << inode->i_blkbits);
656 if (eob)
657 set_buffer_boundary(bh_map);
658 ret = 0;
659out:
660 release_metapath(&mp);
661 trace_gfs2_bmap(ip, bh_map, lblock, create, ret);
662 bmap_unlock(ip, create);
663 return ret;
664
665do_alloc:
666 /* All allocations are done here, firstly check create flag */
667 if (!create) {
668 BUG_ON(gfs2_is_stuffed(ip));
669 ret = 0;
670 goto out;
671 }
672
673 /* At this point ret is the tree depth of already allocated blocks */
674 ret = gfs2_bmap_alloc(inode, lblock, bh_map, &mp, ret, height, maxlen);
675 goto out;
676}
677
678/*
679 * Deprecated: do not use in new code
680 */
681int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
682{
683 struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };
684 int ret;
685 int create = *new;
686
687 BUG_ON(!extlen);
688 BUG_ON(!dblock);
689 BUG_ON(!new);
690
691 bh.b_size = 1 << (inode->i_blkbits + (create ? 0 : 5));
692 ret = gfs2_block_map(inode, lblock, &bh, create);
693 *extlen = bh.b_size >> inode->i_blkbits;
694 *dblock = bh.b_blocknr;
695 if (buffer_new(&bh))
696 *new = 1;
697 else
698 *new = 0;
699 return ret;
700}
701
702/**
703 * do_strip - Look for a layer a particular layer of the file and strip it off
704 * @ip: the inode
705 * @dibh: the dinode buffer
706 * @bh: A buffer of pointers
707 * @top: The first pointer in the buffer
708 * @bottom: One more than the last pointer
709 * @height: the height this buffer is at
710 * @data: a pointer to a struct strip_mine
711 *
712 * Returns: errno
713 */
714
715static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
716 struct buffer_head *bh, __be64 *top, __be64 *bottom,
717 unsigned int height, struct strip_mine *sm)
718{
719 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
720 struct gfs2_rgrp_list rlist;
721 u64 bn, bstart;
722 u32 blen, btotal;
723 __be64 *p;
724 unsigned int rg_blocks = 0;
725 int metadata;
726 unsigned int revokes = 0;
727 int x;
728 int error;
729
730 error = gfs2_rindex_update(sdp);
731 if (error)
732 return error;
733
734 if (!*top)
735 sm->sm_first = 0;
736
737 if (height != sm->sm_height)
738 return 0;
739
740 if (sm->sm_first) {
741 top++;
742 sm->sm_first = 0;
743 }
744
745 metadata = (height != ip->i_height - 1);
746 if (metadata)
747 revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs;
748 else if (ip->i_depth)
749 revokes = sdp->sd_inptrs;
750
751 memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
752 bstart = 0;
753 blen = 0;
754
755 for (p = top; p < bottom; p++) {
756 if (!*p)
757 continue;
758
759 bn = be64_to_cpu(*p);
760
761 if (bstart + blen == bn)
762 blen++;
763 else {
764 if (bstart)
765 gfs2_rlist_add(ip, &rlist, bstart);
766
767 bstart = bn;
768 blen = 1;
769 }
770 }
771
772 if (bstart)
773 gfs2_rlist_add(ip, &rlist, bstart);
774 else
775 goto out; /* Nothing to do */
776
777 gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
778
779 for (x = 0; x < rlist.rl_rgrps; x++) {
780 struct gfs2_rgrpd *rgd;
781 rgd = rlist.rl_ghs[x].gh_gl->gl_object;
782 rg_blocks += rgd->rd_length;
783 }
784
785 error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
786 if (error)
787 goto out_rlist;
788
789 if (gfs2_rs_active(ip->i_res)) /* needs to be done with the rgrp glock held */
790 gfs2_rs_deltree(ip->i_res);
791
792 error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE +
793 RES_INDIRECT + RES_STATFS + RES_QUOTA,
794 revokes);
795 if (error)
796 goto out_rg_gunlock;
797
798 down_write(&ip->i_rw_mutex);
799
800 gfs2_trans_add_meta(ip->i_gl, dibh);
801 gfs2_trans_add_meta(ip->i_gl, bh);
802
803 bstart = 0;
804 blen = 0;
805 btotal = 0;
806
807 for (p = top; p < bottom; p++) {
808 if (!*p)
809 continue;
810
811 bn = be64_to_cpu(*p);
812
813 if (bstart + blen == bn)
814 blen++;
815 else {
816 if (bstart) {
817 __gfs2_free_blocks(ip, bstart, blen, metadata);
818 btotal += blen;
819 }
820
821 bstart = bn;
822 blen = 1;
823 }
824
825 *p = 0;
826 gfs2_add_inode_blocks(&ip->i_inode, -1);
827 }
828 if (bstart) {
829 __gfs2_free_blocks(ip, bstart, blen, metadata);
830 btotal += blen;
831 }
832
833 gfs2_statfs_change(sdp, 0, +btotal, 0);
834 gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
835 ip->i_inode.i_gid);
836
837 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
838
839 gfs2_dinode_out(ip, dibh->b_data);
840
841 up_write(&ip->i_rw_mutex);
842
843 gfs2_trans_end(sdp);
844
845out_rg_gunlock:
846 gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
847out_rlist:
848 gfs2_rlist_free(&rlist);
849out:
850 return error;
851}
852
853/**
854 * recursive_scan - recursively scan through the end of a file
855 * @ip: the inode
856 * @dibh: the dinode buffer
857 * @mp: the path through the metadata to the point to start
858 * @height: the height the recursion is at
859 * @block: the indirect block to look at
860 * @first: 1 if this is the first block
861 * @sm: data opaque to this function to pass to @bc
862 *
863 * When this is first called @height and @block should be zero and
864 * @first should be 1.
865 *
866 * Returns: errno
867 */
868
869static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh,
870 struct metapath *mp, unsigned int height,
871 u64 block, int first, struct strip_mine *sm)
872{
873 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
874 struct buffer_head *bh = NULL;
875 __be64 *top, *bottom;
876 u64 bn;
877 int error;
878 int mh_size = sizeof(struct gfs2_meta_header);
879
880 if (!height) {
881 error = gfs2_meta_inode_buffer(ip, &bh);
882 if (error)
883 return error;
884 dibh = bh;
885
886 top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0];
887 bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs;
888 } else {
889 error = gfs2_meta_indirect_buffer(ip, height, block, &bh);
890 if (error)
891 return error;
892
893 top = (__be64 *)(bh->b_data + mh_size) +
894 (first ? mp->mp_list[height] : 0);
895
896 bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs;
897 }
898
899 error = do_strip(ip, dibh, bh, top, bottom, height, sm);
900 if (error)
901 goto out;
902
903 if (height < ip->i_height - 1) {
904
905 gfs2_metapath_ra(ip->i_gl, bh, top);
906
907 for (; top < bottom; top++, first = 0) {
908 if (!*top)
909 continue;
910
911 bn = be64_to_cpu(*top);
912
913 error = recursive_scan(ip, dibh, mp, height + 1, bn,
914 first, sm);
915 if (error)
916 break;
917 }
918 }
919out:
920 brelse(bh);
921 return error;
922}
923
924
925/**
926 * gfs2_block_truncate_page - Deal with zeroing out data for truncate
927 *
928 * This is partly borrowed from ext3.
929 */
930static int gfs2_block_truncate_page(struct address_space *mapping, loff_t from)
931{
932 struct inode *inode = mapping->host;
933 struct gfs2_inode *ip = GFS2_I(inode);
934 unsigned long index = from >> PAGE_CACHE_SHIFT;
935 unsigned offset = from & (PAGE_CACHE_SIZE-1);
936 unsigned blocksize, iblock, length, pos;
937 struct buffer_head *bh;
938 struct page *page;
939 int err;
940
941 page = find_or_create_page(mapping, index, GFP_NOFS);
942 if (!page)
943 return 0;
944
945 blocksize = inode->i_sb->s_blocksize;
946 length = blocksize - (offset & (blocksize - 1));
947 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
948
949 if (!page_has_buffers(page))
950 create_empty_buffers(page, blocksize, 0);
951
952 /* Find the buffer that contains "offset" */
953 bh = page_buffers(page);
954 pos = blocksize;
955 while (offset >= pos) {
956 bh = bh->b_this_page;
957 iblock++;
958 pos += blocksize;
959 }
960
961 err = 0;
962
963 if (!buffer_mapped(bh)) {
964 gfs2_block_map(inode, iblock, bh, 0);
965 /* unmapped? It's a hole - nothing to do */
966 if (!buffer_mapped(bh))
967 goto unlock;
968 }
969
970 /* Ok, it's mapped. Make sure it's up-to-date */
971 if (PageUptodate(page))
972 set_buffer_uptodate(bh);
973
974 if (!buffer_uptodate(bh)) {
975 err = -EIO;
976 ll_rw_block(READ, 1, &bh);
977 wait_on_buffer(bh);
978 /* Uhhuh. Read error. Complain and punt. */
979 if (!buffer_uptodate(bh))
980 goto unlock;
981 err = 0;
982 }
983
984 if (!gfs2_is_writeback(ip))
985 gfs2_trans_add_data(ip->i_gl, bh);
986
987 zero_user(page, offset, length);
988 mark_buffer_dirty(bh);
989unlock:
990 unlock_page(page);
991 page_cache_release(page);
992 return err;
993}
994
995/**
996 * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files
997 * @inode: The inode being truncated
998 * @oldsize: The original (larger) size
999 * @newsize: The new smaller size
1000 *
1001 * With jdata files, we have to journal a revoke for each block which is
1002 * truncated. As a result, we need to split this into separate transactions
1003 * if the number of pages being truncated gets too large.
1004 */
1005
1006#define GFS2_JTRUNC_REVOKES 8192
1007
1008static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize)
1009{
1010 struct gfs2_sbd *sdp = GFS2_SB(inode);
1011 u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
1012 u64 chunk;
1013 int error;
1014
1015 while (oldsize != newsize) {
1016 chunk = oldsize - newsize;
1017 if (chunk > max_chunk)
1018 chunk = max_chunk;
1019 truncate_pagecache(inode, oldsize - chunk);
1020 oldsize -= chunk;
1021 gfs2_trans_end(sdp);
1022 error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
1023 if (error)
1024 return error;
1025 }
1026
1027 return 0;
1028}
1029
1030static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize)
1031{
1032 struct gfs2_inode *ip = GFS2_I(inode);
1033 struct gfs2_sbd *sdp = GFS2_SB(inode);
1034 struct address_space *mapping = inode->i_mapping;
1035 struct buffer_head *dibh;
1036 int journaled = gfs2_is_jdata(ip);
1037 int error;
1038
1039 if (journaled)
1040 error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES);
1041 else
1042 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1043 if (error)
1044 return error;
1045
1046 error = gfs2_meta_inode_buffer(ip, &dibh);
1047 if (error)
1048 goto out;
1049
1050 gfs2_trans_add_meta(ip->i_gl, dibh);
1051
1052 if (gfs2_is_stuffed(ip)) {
1053 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize);
1054 } else {
1055 if (newsize & (u64)(sdp->sd_sb.sb_bsize - 1)) {
1056 error = gfs2_block_truncate_page(mapping, newsize);
1057 if (error)
1058 goto out_brelse;
1059 }
1060 ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG;
1061 }
1062
1063 i_size_write(inode, newsize);
1064 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1065 gfs2_dinode_out(ip, dibh->b_data);
1066
1067 if (journaled)
1068 error = gfs2_journaled_truncate(inode, oldsize, newsize);
1069 else
1070 truncate_pagecache(inode, newsize);
1071
1072 if (error) {
1073 brelse(dibh);
1074 return error;
1075 }
1076
1077out_brelse:
1078 brelse(dibh);
1079out:
1080 gfs2_trans_end(sdp);
1081 return error;
1082}
1083
1084static int trunc_dealloc(struct gfs2_inode *ip, u64 size)
1085{
1086 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1087 unsigned int height = ip->i_height;
1088 u64 lblock;
1089 struct metapath mp;
1090 int error;
1091
1092 if (!size)
1093 lblock = 0;
1094 else
1095 lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift;
1096
1097 find_metapath(sdp, lblock, &mp, ip->i_height);
1098 error = gfs2_rindex_update(sdp);
1099 if (error)
1100 return error;
1101
1102 error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1103 if (error)
1104 return error;
1105
1106 while (height--) {
1107 struct strip_mine sm;
1108 sm.sm_first = !!size;
1109 sm.sm_height = height;
1110
1111 error = recursive_scan(ip, NULL, &mp, 0, 0, 1, &sm);
1112 if (error)
1113 break;
1114 }
1115
1116 gfs2_quota_unhold(ip);
1117
1118 return error;
1119}
1120
1121static int trunc_end(struct gfs2_inode *ip)
1122{
1123 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1124 struct buffer_head *dibh;
1125 int error;
1126
1127 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1128 if (error)
1129 return error;
1130
1131 down_write(&ip->i_rw_mutex);
1132
1133 error = gfs2_meta_inode_buffer(ip, &dibh);
1134 if (error)
1135 goto out;
1136
1137 if (!i_size_read(&ip->i_inode)) {
1138 ip->i_height = 0;
1139 ip->i_goal = ip->i_no_addr;
1140 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
1141 gfs2_ordered_del_inode(ip);
1142 }
1143 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1144 ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG;
1145
1146 gfs2_trans_add_meta(ip->i_gl, dibh);
1147 gfs2_dinode_out(ip, dibh->b_data);
1148 brelse(dibh);
1149
1150out:
1151 up_write(&ip->i_rw_mutex);
1152 gfs2_trans_end(sdp);
1153 return error;
1154}
1155
1156/**
1157 * do_shrink - make a file smaller
1158 * @inode: the inode
1159 * @oldsize: the current inode size
1160 * @newsize: the size to make the file
1161 *
1162 * Called with an exclusive lock on @inode. The @size must
1163 * be equal to or smaller than the current inode size.
1164 *
1165 * Returns: errno
1166 */
1167
1168static int do_shrink(struct inode *inode, u64 oldsize, u64 newsize)
1169{
1170 struct gfs2_inode *ip = GFS2_I(inode);
1171 int error;
1172
1173 error = trunc_start(inode, oldsize, newsize);
1174 if (error < 0)
1175 return error;
1176 if (gfs2_is_stuffed(ip))
1177 return 0;
1178
1179 error = trunc_dealloc(ip, newsize);
1180 if (error == 0)
1181 error = trunc_end(ip);
1182
1183 return error;
1184}
1185
1186void gfs2_trim_blocks(struct inode *inode)
1187{
1188 u64 size = inode->i_size;
1189 int ret;
1190
1191 ret = do_shrink(inode, size, size);
1192 WARN_ON(ret != 0);
1193}
1194
1195/**
1196 * do_grow - Touch and update inode size
1197 * @inode: The inode
1198 * @size: The new size
1199 *
1200 * This function updates the timestamps on the inode and
1201 * may also increase the size of the inode. This function
1202 * must not be called with @size any smaller than the current
1203 * inode size.
1204 *
1205 * Although it is not strictly required to unstuff files here,
1206 * earlier versions of GFS2 have a bug in the stuffed file reading
1207 * code which will result in a buffer overrun if the size is larger
1208 * than the max stuffed file size. In order to prevent this from
1209 * occurring, such files are unstuffed, but in other cases we can
1210 * just update the inode size directly.
1211 *
1212 * Returns: 0 on success, or -ve on error
1213 */
1214
1215static int do_grow(struct inode *inode, u64 size)
1216{
1217 struct gfs2_inode *ip = GFS2_I(inode);
1218 struct gfs2_sbd *sdp = GFS2_SB(inode);
1219 struct gfs2_alloc_parms ap = { .target = 1, };
1220 struct buffer_head *dibh;
1221 int error;
1222 int unstuff = 0;
1223
1224 if (gfs2_is_stuffed(ip) &&
1225 (size > (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)))) {
1226 error = gfs2_quota_lock_check(ip);
1227 if (error)
1228 return error;
1229
1230 error = gfs2_inplace_reserve(ip, &ap);
1231 if (error)
1232 goto do_grow_qunlock;
1233 unstuff = 1;
1234 }
1235
1236 error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT +
1237 (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF ?
1238 0 : RES_QUOTA), 0);
1239 if (error)
1240 goto do_grow_release;
1241
1242 if (unstuff) {
1243 error = gfs2_unstuff_dinode(ip, NULL);
1244 if (error)
1245 goto do_end_trans;
1246 }
1247
1248 error = gfs2_meta_inode_buffer(ip, &dibh);
1249 if (error)
1250 goto do_end_trans;
1251
1252 i_size_write(inode, size);
1253 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1254 gfs2_trans_add_meta(ip->i_gl, dibh);
1255 gfs2_dinode_out(ip, dibh->b_data);
1256 brelse(dibh);
1257
1258do_end_trans:
1259 gfs2_trans_end(sdp);
1260do_grow_release:
1261 if (unstuff) {
1262 gfs2_inplace_release(ip);
1263do_grow_qunlock:
1264 gfs2_quota_unlock(ip);
1265 }
1266 return error;
1267}
1268
1269/**
1270 * gfs2_setattr_size - make a file a given size
1271 * @inode: the inode
1272 * @newsize: the size to make the file
1273 *
1274 * The file size can grow, shrink, or stay the same size. This
1275 * is called holding i_mutex and an exclusive glock on the inode
1276 * in question.
1277 *
1278 * Returns: errno
1279 */
1280
1281int gfs2_setattr_size(struct inode *inode, u64 newsize)
1282{
1283 struct gfs2_inode *ip = GFS2_I(inode);
1284 int ret;
1285 u64 oldsize;
1286
1287 BUG_ON(!S_ISREG(inode->i_mode));
1288
1289 ret = inode_newsize_ok(inode, newsize);
1290 if (ret)
1291 return ret;
1292
1293 ret = get_write_access(inode);
1294 if (ret)
1295 return ret;
1296
1297 inode_dio_wait(inode);
1298
1299 ret = gfs2_rs_alloc(ip);
1300 if (ret)
1301 goto out;
1302
1303 oldsize = inode->i_size;
1304 if (newsize >= oldsize) {
1305 ret = do_grow(inode, newsize);
1306 goto out;
1307 }
1308
1309 gfs2_rs_deltree(ip->i_res);
1310 ret = do_shrink(inode, oldsize, newsize);
1311out:
1312 put_write_access(inode);
1313 return ret;
1314}
1315
1316int gfs2_truncatei_resume(struct gfs2_inode *ip)
1317{
1318 int error;
1319 error = trunc_dealloc(ip, i_size_read(&ip->i_inode));
1320 if (!error)
1321 error = trunc_end(ip);
1322 return error;
1323}
1324
1325int gfs2_file_dealloc(struct gfs2_inode *ip)
1326{
1327 return trunc_dealloc(ip, 0);
1328}
1329
1330/**
1331 * gfs2_free_journal_extents - Free cached journal bmap info
1332 * @jd: The journal
1333 *
1334 */
1335
1336void gfs2_free_journal_extents(struct gfs2_jdesc *jd)
1337{
1338 struct gfs2_journal_extent *jext;
1339
1340 while(!list_empty(&jd->extent_list)) {
1341 jext = list_entry(jd->extent_list.next, struct gfs2_journal_extent, list);
1342 list_del(&jext->list);
1343 kfree(jext);
1344 }
1345}
1346
1347/**
1348 * gfs2_add_jextent - Add or merge a new extent to extent cache
1349 * @jd: The journal descriptor
1350 * @lblock: The logical block at start of new extent
1351 * @pblock: The physical block at start of new extent
1352 * @blocks: Size of extent in fs blocks
1353 *
1354 * Returns: 0 on success or -ENOMEM
1355 */
1356
1357static int gfs2_add_jextent(struct gfs2_jdesc *jd, u64 lblock, u64 dblock, u64 blocks)
1358{
1359 struct gfs2_journal_extent *jext;
1360
1361 if (!list_empty(&jd->extent_list)) {
1362 jext = list_entry(jd->extent_list.prev, struct gfs2_journal_extent, list);
1363 if ((jext->dblock + jext->blocks) == dblock) {
1364 jext->blocks += blocks;
1365 return 0;
1366 }
1367 }
1368
1369 jext = kzalloc(sizeof(struct gfs2_journal_extent), GFP_NOFS);
1370 if (jext == NULL)
1371 return -ENOMEM;
1372 jext->dblock = dblock;
1373 jext->lblock = lblock;
1374 jext->blocks = blocks;
1375 list_add_tail(&jext->list, &jd->extent_list);
1376 jd->nr_extents++;
1377 return 0;
1378}
1379
1380/**
1381 * gfs2_map_journal_extents - Cache journal bmap info
1382 * @sdp: The super block
1383 * @jd: The journal to map
1384 *
1385 * Create a reusable "extent" mapping from all logical
1386 * blocks to all physical blocks for the given journal. This will save
1387 * us time when writing journal blocks. Most journals will have only one
1388 * extent that maps all their logical blocks. That's because gfs2.mkfs
1389 * arranges the journal blocks sequentially to maximize performance.
1390 * So the extent would map the first block for the entire file length.
1391 * However, gfs2_jadd can happen while file activity is happening, so
1392 * those journals may not be sequential. Less likely is the case where
1393 * the users created their own journals by mounting the metafs and
1394 * laying it out. But it's still possible. These journals might have
1395 * several extents.
1396 *
1397 * Returns: 0 on success, or error on failure
1398 */
1399
1400int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
1401{
1402 u64 lblock = 0;
1403 u64 lblock_stop;
1404 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
1405 struct buffer_head bh;
1406 unsigned int shift = sdp->sd_sb.sb_bsize_shift;
1407 u64 size;
1408 int rc;
1409
1410 lblock_stop = i_size_read(jd->jd_inode) >> shift;
1411 size = (lblock_stop - lblock) << shift;
1412 jd->nr_extents = 0;
1413 WARN_ON(!list_empty(&jd->extent_list));
1414
1415 do {
1416 bh.b_state = 0;
1417 bh.b_blocknr = 0;
1418 bh.b_size = size;
1419 rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
1420 if (rc || !buffer_mapped(&bh))
1421 goto fail;
1422 rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
1423 if (rc)
1424 goto fail;
1425 size -= bh.b_size;
1426 lblock += (bh.b_size >> ip->i_inode.i_blkbits);
1427 } while(size > 0);
1428
1429 fs_info(sdp, "journal %d mapped with %u extents\n", jd->jd_jid,
1430 jd->nr_extents);
1431 return 0;
1432
1433fail:
1434 fs_warn(sdp, "error %d mapping journal %u at offset %llu (extent %u)\n",
1435 rc, jd->jd_jid,
1436 (unsigned long long)(i_size_read(jd->jd_inode) - size),
1437 jd->nr_extents);
1438 fs_warn(sdp, "bmap=%d lblock=%llu block=%llu, state=0x%08lx, size=%llu\n",
1439 rc, (unsigned long long)lblock, (unsigned long long)bh.b_blocknr,
1440 bh.b_state, (unsigned long long)bh.b_size);
1441 gfs2_free_journal_extents(jd);
1442 return rc;
1443}
1444
1445/**
1446 * gfs2_write_alloc_required - figure out if a write will require an allocation
1447 * @ip: the file being written to
1448 * @offset: the offset to write to
1449 * @len: the number of bytes being written
1450 *
1451 * Returns: 1 if an alloc is required, 0 otherwise
1452 */
1453
1454int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
1455 unsigned int len)
1456{
1457 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1458 struct buffer_head bh;
1459 unsigned int shift;
1460 u64 lblock, lblock_stop, size;
1461 u64 end_of_file;
1462
1463 if (!len)
1464 return 0;
1465
1466 if (gfs2_is_stuffed(ip)) {
1467 if (offset + len >
1468 sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
1469 return 1;
1470 return 0;
1471 }
1472
1473 shift = sdp->sd_sb.sb_bsize_shift;
1474 BUG_ON(gfs2_is_dir(ip));
1475 end_of_file = (i_size_read(&ip->i_inode) + sdp->sd_sb.sb_bsize - 1) >> shift;
1476 lblock = offset >> shift;
1477 lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
1478 if (lblock_stop > end_of_file)
1479 return 1;
1480
1481 size = (lblock_stop - lblock) << shift;
1482 do {
1483 bh.b_state = 0;
1484 bh.b_size = size;
1485 gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
1486 if (!buffer_mapped(&bh))
1487 return 1;
1488 size -= bh.b_size;
1489 lblock += (bh.b_size >> ip->i_inode.i_blkbits);
1490 } while(size > 0);
1491
1492 return 0;
1493}
1494
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 */
6
7#include <linux/spinlock.h>
8#include <linux/completion.h>
9#include <linux/buffer_head.h>
10#include <linux/blkdev.h>
11#include <linux/gfs2_ondisk.h>
12#include <linux/crc32.h>
13#include <linux/iomap.h>
14#include <linux/ktime.h>
15
16#include "gfs2.h"
17#include "incore.h"
18#include "bmap.h"
19#include "glock.h"
20#include "inode.h"
21#include "meta_io.h"
22#include "quota.h"
23#include "rgrp.h"
24#include "log.h"
25#include "super.h"
26#include "trans.h"
27#include "dir.h"
28#include "util.h"
29#include "aops.h"
30#include "trace_gfs2.h"
31
32/* This doesn't need to be that large as max 64 bit pointers in a 4k
33 * block is 512, so __u16 is fine for that. It saves stack space to
34 * keep it small.
35 */
36struct metapath {
37 struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT];
38 __u16 mp_list[GFS2_MAX_META_HEIGHT];
39 int mp_fheight; /* find_metapath height */
40 int mp_aheight; /* actual height (lookup height) */
41};
42
43static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length);
44
45/**
46 * gfs2_unstuffer_folio - unstuff a stuffed inode into a block cached by a folio
47 * @ip: the inode
48 * @dibh: the dinode buffer
49 * @block: the block number that was allocated
50 * @folio: The folio.
51 *
52 * Returns: errno
53 */
54static int gfs2_unstuffer_folio(struct gfs2_inode *ip, struct buffer_head *dibh,
55 u64 block, struct folio *folio)
56{
57 struct inode *inode = &ip->i_inode;
58
59 if (!folio_test_uptodate(folio)) {
60 void *kaddr = kmap_local_folio(folio, 0);
61 u64 dsize = i_size_read(inode);
62
63 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
64 memset(kaddr + dsize, 0, folio_size(folio) - dsize);
65 kunmap_local(kaddr);
66
67 folio_mark_uptodate(folio);
68 }
69
70 if (gfs2_is_jdata(ip)) {
71 struct buffer_head *bh = folio_buffers(folio);
72
73 if (!bh)
74 bh = create_empty_buffers(folio,
75 BIT(inode->i_blkbits), BIT(BH_Uptodate));
76
77 if (!buffer_mapped(bh))
78 map_bh(bh, inode->i_sb, block);
79
80 set_buffer_uptodate(bh);
81 gfs2_trans_add_data(ip->i_gl, bh);
82 } else {
83 folio_mark_dirty(folio);
84 gfs2_ordered_add_inode(ip);
85 }
86
87 return 0;
88}
89
90static int __gfs2_unstuff_inode(struct gfs2_inode *ip, struct folio *folio)
91{
92 struct buffer_head *bh, *dibh;
93 struct gfs2_dinode *di;
94 u64 block = 0;
95 int isdir = gfs2_is_dir(ip);
96 int error;
97
98 error = gfs2_meta_inode_buffer(ip, &dibh);
99 if (error)
100 return error;
101
102 if (i_size_read(&ip->i_inode)) {
103 /* Get a free block, fill it with the stuffed data,
104 and write it out to disk */
105
106 unsigned int n = 1;
107 error = gfs2_alloc_blocks(ip, &block, &n, 0);
108 if (error)
109 goto out_brelse;
110 if (isdir) {
111 gfs2_trans_remove_revoke(GFS2_SB(&ip->i_inode), block, 1);
112 error = gfs2_dir_get_new_buffer(ip, block, &bh);
113 if (error)
114 goto out_brelse;
115 gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header),
116 dibh, sizeof(struct gfs2_dinode));
117 brelse(bh);
118 } else {
119 error = gfs2_unstuffer_folio(ip, dibh, block, folio);
120 if (error)
121 goto out_brelse;
122 }
123 }
124
125 /* Set up the pointer to the new block */
126
127 gfs2_trans_add_meta(ip->i_gl, dibh);
128 di = (struct gfs2_dinode *)dibh->b_data;
129 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
130
131 if (i_size_read(&ip->i_inode)) {
132 *(__be64 *)(di + 1) = cpu_to_be64(block);
133 gfs2_add_inode_blocks(&ip->i_inode, 1);
134 di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
135 }
136
137 ip->i_height = 1;
138 di->di_height = cpu_to_be16(1);
139
140out_brelse:
141 brelse(dibh);
142 return error;
143}
144
145/**
146 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
147 * @ip: The GFS2 inode to unstuff
148 *
149 * This routine unstuffs a dinode and returns it to a "normal" state such
150 * that the height can be grown in the traditional way.
151 *
152 * Returns: errno
153 */
154
155int gfs2_unstuff_dinode(struct gfs2_inode *ip)
156{
157 struct inode *inode = &ip->i_inode;
158 struct folio *folio;
159 int error;
160
161 down_write(&ip->i_rw_mutex);
162 folio = filemap_grab_folio(inode->i_mapping, 0);
163 error = PTR_ERR(folio);
164 if (IS_ERR(folio))
165 goto out;
166 error = __gfs2_unstuff_inode(ip, folio);
167 folio_unlock(folio);
168 folio_put(folio);
169out:
170 up_write(&ip->i_rw_mutex);
171 return error;
172}
173
174/**
175 * find_metapath - Find path through the metadata tree
176 * @sdp: The superblock
177 * @block: The disk block to look up
178 * @mp: The metapath to return the result in
179 * @height: The pre-calculated height of the metadata tree
180 *
181 * This routine returns a struct metapath structure that defines a path
182 * through the metadata of inode "ip" to get to block "block".
183 *
184 * Example:
185 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a
186 * filesystem with a blocksize of 4096.
187 *
188 * find_metapath() would return a struct metapath structure set to:
189 * mp_fheight = 3, mp_list[0] = 0, mp_list[1] = 48, and mp_list[2] = 165.
190 *
191 * That means that in order to get to the block containing the byte at
192 * offset 101342453, we would load the indirect block pointed to by pointer
193 * 0 in the dinode. We would then load the indirect block pointed to by
194 * pointer 48 in that indirect block. We would then load the data block
195 * pointed to by pointer 165 in that indirect block.
196 *
197 * ----------------------------------------
198 * | Dinode | |
199 * | | 4|
200 * | |0 1 2 3 4 5 9|
201 * | | 6|
202 * ----------------------------------------
203 * |
204 * |
205 * V
206 * ----------------------------------------
207 * | Indirect Block |
208 * | 5|
209 * | 4 4 4 4 4 5 5 1|
210 * |0 5 6 7 8 9 0 1 2|
211 * ----------------------------------------
212 * |
213 * |
214 * V
215 * ----------------------------------------
216 * | Indirect Block |
217 * | 1 1 1 1 1 5|
218 * | 6 6 6 6 6 1|
219 * |0 3 4 5 6 7 2|
220 * ----------------------------------------
221 * |
222 * |
223 * V
224 * ----------------------------------------
225 * | Data block containing offset |
226 * | 101342453 |
227 * | |
228 * | |
229 * ----------------------------------------
230 *
231 */
232
233static void find_metapath(const struct gfs2_sbd *sdp, u64 block,
234 struct metapath *mp, unsigned int height)
235{
236 unsigned int i;
237
238 mp->mp_fheight = height;
239 for (i = height; i--;)
240 mp->mp_list[i] = do_div(block, sdp->sd_inptrs);
241}
242
243static inline unsigned int metapath_branch_start(const struct metapath *mp)
244{
245 if (mp->mp_list[0] == 0)
246 return 2;
247 return 1;
248}
249
250/**
251 * metaptr1 - Return the first possible metadata pointer in a metapath buffer
252 * @height: The metadata height (0 = dinode)
253 * @mp: The metapath
254 */
255static inline __be64 *metaptr1(unsigned int height, const struct metapath *mp)
256{
257 struct buffer_head *bh = mp->mp_bh[height];
258 if (height == 0)
259 return ((__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)));
260 return ((__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header)));
261}
262
263/**
264 * metapointer - Return pointer to start of metadata in a buffer
265 * @height: The metadata height (0 = dinode)
266 * @mp: The metapath
267 *
268 * Return a pointer to the block number of the next height of the metadata
269 * tree given a buffer containing the pointer to the current height of the
270 * metadata tree.
271 */
272
273static inline __be64 *metapointer(unsigned int height, const struct metapath *mp)
274{
275 __be64 *p = metaptr1(height, mp);
276 return p + mp->mp_list[height];
277}
278
279static inline const __be64 *metaend(unsigned int height, const struct metapath *mp)
280{
281 const struct buffer_head *bh = mp->mp_bh[height];
282 return (const __be64 *)(bh->b_data + bh->b_size);
283}
284
285static void clone_metapath(struct metapath *clone, struct metapath *mp)
286{
287 unsigned int hgt;
288
289 *clone = *mp;
290 for (hgt = 0; hgt < mp->mp_aheight; hgt++)
291 get_bh(clone->mp_bh[hgt]);
292}
293
294static void gfs2_metapath_ra(struct gfs2_glock *gl, __be64 *start, __be64 *end)
295{
296 const __be64 *t;
297
298 for (t = start; t < end; t++) {
299 struct buffer_head *rabh;
300
301 if (!*t)
302 continue;
303
304 rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE);
305 if (trylock_buffer(rabh)) {
306 if (!buffer_uptodate(rabh)) {
307 rabh->b_end_io = end_buffer_read_sync;
308 submit_bh(REQ_OP_READ | REQ_RAHEAD | REQ_META |
309 REQ_PRIO, rabh);
310 continue;
311 }
312 unlock_buffer(rabh);
313 }
314 brelse(rabh);
315 }
316}
317
318static inline struct buffer_head *
319metapath_dibh(struct metapath *mp)
320{
321 return mp->mp_bh[0];
322}
323
324static int __fillup_metapath(struct gfs2_inode *ip, struct metapath *mp,
325 unsigned int x, unsigned int h)
326{
327 for (; x < h; x++) {
328 __be64 *ptr = metapointer(x, mp);
329 u64 dblock = be64_to_cpu(*ptr);
330 int ret;
331
332 if (!dblock)
333 break;
334 ret = gfs2_meta_buffer(ip, GFS2_METATYPE_IN, dblock, &mp->mp_bh[x + 1]);
335 if (ret)
336 return ret;
337 }
338 mp->mp_aheight = x + 1;
339 return 0;
340}
341
342/**
343 * lookup_metapath - Walk the metadata tree to a specific point
344 * @ip: The inode
345 * @mp: The metapath
346 *
347 * Assumes that the inode's buffer has already been looked up and
348 * hooked onto mp->mp_bh[0] and that the metapath has been initialised
349 * by find_metapath().
350 *
351 * If this function encounters part of the tree which has not been
352 * allocated, it returns the current height of the tree at the point
353 * at which it found the unallocated block. Blocks which are found are
354 * added to the mp->mp_bh[] list.
355 *
356 * Returns: error
357 */
358
359static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
360{
361 return __fillup_metapath(ip, mp, 0, ip->i_height - 1);
362}
363
364/**
365 * fillup_metapath - fill up buffers for the metadata path to a specific height
366 * @ip: The inode
367 * @mp: The metapath
368 * @h: The height to which it should be mapped
369 *
370 * Similar to lookup_metapath, but does lookups for a range of heights
371 *
372 * Returns: error or the number of buffers filled
373 */
374
375static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h)
376{
377 unsigned int x = 0;
378 int ret;
379
380 if (h) {
381 /* find the first buffer we need to look up. */
382 for (x = h - 1; x > 0; x--) {
383 if (mp->mp_bh[x])
384 break;
385 }
386 }
387 ret = __fillup_metapath(ip, mp, x, h);
388 if (ret)
389 return ret;
390 return mp->mp_aheight - x - 1;
391}
392
393static sector_t metapath_to_block(struct gfs2_sbd *sdp, struct metapath *mp)
394{
395 sector_t factor = 1, block = 0;
396 int hgt;
397
398 for (hgt = mp->mp_fheight - 1; hgt >= 0; hgt--) {
399 if (hgt < mp->mp_aheight)
400 block += mp->mp_list[hgt] * factor;
401 factor *= sdp->sd_inptrs;
402 }
403 return block;
404}
405
406static void release_metapath(struct metapath *mp)
407{
408 int i;
409
410 for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) {
411 if (mp->mp_bh[i] == NULL)
412 break;
413 brelse(mp->mp_bh[i]);
414 mp->mp_bh[i] = NULL;
415 }
416}
417
418/**
419 * gfs2_extent_length - Returns length of an extent of blocks
420 * @bh: The metadata block
421 * @ptr: Current position in @bh
422 * @eob: Set to 1 if we hit "end of block"
423 *
424 * Returns: The length of the extent (minimum of one block)
425 */
426
427static inline unsigned int gfs2_extent_length(struct buffer_head *bh, __be64 *ptr, int *eob)
428{
429 const __be64 *end = (__be64 *)(bh->b_data + bh->b_size);
430 const __be64 *first = ptr;
431 u64 d = be64_to_cpu(*ptr);
432
433 *eob = 0;
434 do {
435 ptr++;
436 if (ptr >= end)
437 break;
438 d++;
439 } while(be64_to_cpu(*ptr) == d);
440 if (ptr >= end)
441 *eob = 1;
442 return ptr - first;
443}
444
445enum walker_status { WALK_STOP, WALK_FOLLOW, WALK_CONTINUE };
446
447/*
448 * gfs2_metadata_walker - walk an indirect block
449 * @mp: Metapath to indirect block
450 * @ptrs: Number of pointers to look at
451 *
452 * When returning WALK_FOLLOW, the walker must update @mp to point at the right
453 * indirect block to follow.
454 */
455typedef enum walker_status (*gfs2_metadata_walker)(struct metapath *mp,
456 unsigned int ptrs);
457
458/*
459 * gfs2_walk_metadata - walk a tree of indirect blocks
460 * @inode: The inode
461 * @mp: Starting point of walk
462 * @max_len: Maximum number of blocks to walk
463 * @walker: Called during the walk
464 *
465 * Returns 1 if the walk was stopped by @walker, 0 if we went past @max_len or
466 * past the end of metadata, and a negative error code otherwise.
467 */
468
469static int gfs2_walk_metadata(struct inode *inode, struct metapath *mp,
470 u64 max_len, gfs2_metadata_walker walker)
471{
472 struct gfs2_inode *ip = GFS2_I(inode);
473 struct gfs2_sbd *sdp = GFS2_SB(inode);
474 u64 factor = 1;
475 unsigned int hgt;
476 int ret;
477
478 /*
479 * The walk starts in the lowest allocated indirect block, which may be
480 * before the position indicated by @mp. Adjust @max_len accordingly
481 * to avoid a short walk.
482 */
483 for (hgt = mp->mp_fheight - 1; hgt >= mp->mp_aheight; hgt--) {
484 max_len += mp->mp_list[hgt] * factor;
485 mp->mp_list[hgt] = 0;
486 factor *= sdp->sd_inptrs;
487 }
488
489 for (;;) {
490 u16 start = mp->mp_list[hgt];
491 enum walker_status status;
492 unsigned int ptrs;
493 u64 len;
494
495 /* Walk indirect block. */
496 ptrs = (hgt >= 1 ? sdp->sd_inptrs : sdp->sd_diptrs) - start;
497 len = ptrs * factor;
498 if (len > max_len)
499 ptrs = DIV_ROUND_UP_ULL(max_len, factor);
500 status = walker(mp, ptrs);
501 switch (status) {
502 case WALK_STOP:
503 return 1;
504 case WALK_FOLLOW:
505 BUG_ON(mp->mp_aheight == mp->mp_fheight);
506 ptrs = mp->mp_list[hgt] - start;
507 len = ptrs * factor;
508 break;
509 case WALK_CONTINUE:
510 break;
511 }
512 if (len >= max_len)
513 break;
514 max_len -= len;
515 if (status == WALK_FOLLOW)
516 goto fill_up_metapath;
517
518lower_metapath:
519 /* Decrease height of metapath. */
520 brelse(mp->mp_bh[hgt]);
521 mp->mp_bh[hgt] = NULL;
522 mp->mp_list[hgt] = 0;
523 if (!hgt)
524 break;
525 hgt--;
526 factor *= sdp->sd_inptrs;
527
528 /* Advance in metadata tree. */
529 (mp->mp_list[hgt])++;
530 if (hgt) {
531 if (mp->mp_list[hgt] >= sdp->sd_inptrs)
532 goto lower_metapath;
533 } else {
534 if (mp->mp_list[hgt] >= sdp->sd_diptrs)
535 break;
536 }
537
538fill_up_metapath:
539 /* Increase height of metapath. */
540 ret = fillup_metapath(ip, mp, ip->i_height - 1);
541 if (ret < 0)
542 return ret;
543 hgt += ret;
544 for (; ret; ret--)
545 do_div(factor, sdp->sd_inptrs);
546 mp->mp_aheight = hgt + 1;
547 }
548 return 0;
549}
550
551static enum walker_status gfs2_hole_walker(struct metapath *mp,
552 unsigned int ptrs)
553{
554 const __be64 *start, *ptr, *end;
555 unsigned int hgt;
556
557 hgt = mp->mp_aheight - 1;
558 start = metapointer(hgt, mp);
559 end = start + ptrs;
560
561 for (ptr = start; ptr < end; ptr++) {
562 if (*ptr) {
563 mp->mp_list[hgt] += ptr - start;
564 if (mp->mp_aheight == mp->mp_fheight)
565 return WALK_STOP;
566 return WALK_FOLLOW;
567 }
568 }
569 return WALK_CONTINUE;
570}
571
572/**
573 * gfs2_hole_size - figure out the size of a hole
574 * @inode: The inode
575 * @lblock: The logical starting block number
576 * @len: How far to look (in blocks)
577 * @mp: The metapath at lblock
578 * @iomap: The iomap to store the hole size in
579 *
580 * This function modifies @mp.
581 *
582 * Returns: errno on error
583 */
584static int gfs2_hole_size(struct inode *inode, sector_t lblock, u64 len,
585 struct metapath *mp, struct iomap *iomap)
586{
587 struct metapath clone;
588 u64 hole_size;
589 int ret;
590
591 clone_metapath(&clone, mp);
592 ret = gfs2_walk_metadata(inode, &clone, len, gfs2_hole_walker);
593 if (ret < 0)
594 goto out;
595
596 if (ret == 1)
597 hole_size = metapath_to_block(GFS2_SB(inode), &clone) - lblock;
598 else
599 hole_size = len;
600 iomap->length = hole_size << inode->i_blkbits;
601 ret = 0;
602
603out:
604 release_metapath(&clone);
605 return ret;
606}
607
608static inline void gfs2_indirect_init(struct metapath *mp,
609 struct gfs2_glock *gl, unsigned int i,
610 unsigned offset, u64 bn)
611{
612 __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data +
613 ((i > 1) ? sizeof(struct gfs2_meta_header) :
614 sizeof(struct gfs2_dinode)));
615 BUG_ON(i < 1);
616 BUG_ON(mp->mp_bh[i] != NULL);
617 mp->mp_bh[i] = gfs2_meta_new(gl, bn);
618 gfs2_trans_add_meta(gl, mp->mp_bh[i]);
619 gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN);
620 gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header));
621 ptr += offset;
622 *ptr = cpu_to_be64(bn);
623}
624
625enum alloc_state {
626 ALLOC_DATA = 0,
627 ALLOC_GROW_DEPTH = 1,
628 ALLOC_GROW_HEIGHT = 2,
629 /* ALLOC_UNSTUFF = 3, TBD and rather complicated */
630};
631
632/**
633 * __gfs2_iomap_alloc - Build a metadata tree of the requested height
634 * @inode: The GFS2 inode
635 * @iomap: The iomap structure
636 * @mp: The metapath, with proper height information calculated
637 *
638 * In this routine we may have to alloc:
639 * i) Indirect blocks to grow the metadata tree height
640 * ii) Indirect blocks to fill in lower part of the metadata tree
641 * iii) Data blocks
642 *
643 * This function is called after __gfs2_iomap_get, which works out the
644 * total number of blocks which we need via gfs2_alloc_size.
645 *
646 * We then do the actual allocation asking for an extent at a time (if
647 * enough contiguous free blocks are available, there will only be one
648 * allocation request per call) and uses the state machine to initialise
649 * the blocks in order.
650 *
651 * Right now, this function will allocate at most one indirect block
652 * worth of data -- with a default block size of 4K, that's slightly
653 * less than 2M. If this limitation is ever removed to allow huge
654 * allocations, we would probably still want to limit the iomap size we
655 * return to avoid stalling other tasks during huge writes; the next
656 * iomap iteration would then find the blocks already allocated.
657 *
658 * Returns: errno on error
659 */
660
661static int __gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
662 struct metapath *mp)
663{
664 struct gfs2_inode *ip = GFS2_I(inode);
665 struct gfs2_sbd *sdp = GFS2_SB(inode);
666 struct buffer_head *dibh = metapath_dibh(mp);
667 u64 bn;
668 unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0;
669 size_t dblks = iomap->length >> inode->i_blkbits;
670 const unsigned end_of_metadata = mp->mp_fheight - 1;
671 int ret;
672 enum alloc_state state;
673 __be64 *ptr;
674 __be64 zero_bn = 0;
675
676 BUG_ON(mp->mp_aheight < 1);
677 BUG_ON(dibh == NULL);
678 BUG_ON(dblks < 1);
679
680 gfs2_trans_add_meta(ip->i_gl, dibh);
681
682 down_write(&ip->i_rw_mutex);
683
684 if (mp->mp_fheight == mp->mp_aheight) {
685 /* Bottom indirect block exists */
686 state = ALLOC_DATA;
687 } else {
688 /* Need to allocate indirect blocks */
689 if (mp->mp_fheight == ip->i_height) {
690 /* Writing into existing tree, extend tree down */
691 iblks = mp->mp_fheight - mp->mp_aheight;
692 state = ALLOC_GROW_DEPTH;
693 } else {
694 /* Building up tree height */
695 state = ALLOC_GROW_HEIGHT;
696 iblks = mp->mp_fheight - ip->i_height;
697 branch_start = metapath_branch_start(mp);
698 iblks += (mp->mp_fheight - branch_start);
699 }
700 }
701
702 /* start of the second part of the function (state machine) */
703
704 blks = dblks + iblks;
705 i = mp->mp_aheight;
706 do {
707 n = blks - alloced;
708 ret = gfs2_alloc_blocks(ip, &bn, &n, 0);
709 if (ret)
710 goto out;
711 alloced += n;
712 if (state != ALLOC_DATA || gfs2_is_jdata(ip))
713 gfs2_trans_remove_revoke(sdp, bn, n);
714 switch (state) {
715 /* Growing height of tree */
716 case ALLOC_GROW_HEIGHT:
717 if (i == 1) {
718 ptr = (__be64 *)(dibh->b_data +
719 sizeof(struct gfs2_dinode));
720 zero_bn = *ptr;
721 }
722 for (; i - 1 < mp->mp_fheight - ip->i_height && n > 0;
723 i++, n--)
724 gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++);
725 if (i - 1 == mp->mp_fheight - ip->i_height) {
726 i--;
727 gfs2_buffer_copy_tail(mp->mp_bh[i],
728 sizeof(struct gfs2_meta_header),
729 dibh, sizeof(struct gfs2_dinode));
730 gfs2_buffer_clear_tail(dibh,
731 sizeof(struct gfs2_dinode) +
732 sizeof(__be64));
733 ptr = (__be64 *)(mp->mp_bh[i]->b_data +
734 sizeof(struct gfs2_meta_header));
735 *ptr = zero_bn;
736 state = ALLOC_GROW_DEPTH;
737 for(i = branch_start; i < mp->mp_fheight; i++) {
738 if (mp->mp_bh[i] == NULL)
739 break;
740 brelse(mp->mp_bh[i]);
741 mp->mp_bh[i] = NULL;
742 }
743 i = branch_start;
744 }
745 if (n == 0)
746 break;
747 fallthrough; /* To branching from existing tree */
748 case ALLOC_GROW_DEPTH:
749 if (i > 1 && i < mp->mp_fheight)
750 gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[i-1]);
751 for (; i < mp->mp_fheight && n > 0; i++, n--)
752 gfs2_indirect_init(mp, ip->i_gl, i,
753 mp->mp_list[i-1], bn++);
754 if (i == mp->mp_fheight)
755 state = ALLOC_DATA;
756 if (n == 0)
757 break;
758 fallthrough; /* To tree complete, adding data blocks */
759 case ALLOC_DATA:
760 BUG_ON(n > dblks);
761 BUG_ON(mp->mp_bh[end_of_metadata] == NULL);
762 gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[end_of_metadata]);
763 dblks = n;
764 ptr = metapointer(end_of_metadata, mp);
765 iomap->addr = bn << inode->i_blkbits;
766 iomap->flags |= IOMAP_F_MERGED | IOMAP_F_NEW;
767 while (n-- > 0)
768 *ptr++ = cpu_to_be64(bn++);
769 break;
770 }
771 } while (iomap->addr == IOMAP_NULL_ADDR);
772
773 iomap->type = IOMAP_MAPPED;
774 iomap->length = (u64)dblks << inode->i_blkbits;
775 ip->i_height = mp->mp_fheight;
776 gfs2_add_inode_blocks(&ip->i_inode, alloced);
777 gfs2_dinode_out(ip, dibh->b_data);
778out:
779 up_write(&ip->i_rw_mutex);
780 return ret;
781}
782
783#define IOMAP_F_GFS2_BOUNDARY IOMAP_F_PRIVATE
784
785/**
786 * gfs2_alloc_size - Compute the maximum allocation size
787 * @inode: The inode
788 * @mp: The metapath
789 * @size: Requested size in blocks
790 *
791 * Compute the maximum size of the next allocation at @mp.
792 *
793 * Returns: size in blocks
794 */
795static u64 gfs2_alloc_size(struct inode *inode, struct metapath *mp, u64 size)
796{
797 struct gfs2_inode *ip = GFS2_I(inode);
798 struct gfs2_sbd *sdp = GFS2_SB(inode);
799 const __be64 *first, *ptr, *end;
800
801 /*
802 * For writes to stuffed files, this function is called twice via
803 * __gfs2_iomap_get, before and after unstuffing. The size we return the
804 * first time needs to be large enough to get the reservation and
805 * allocation sizes right. The size we return the second time must
806 * be exact or else __gfs2_iomap_alloc won't do the right thing.
807 */
808
809 if (gfs2_is_stuffed(ip) || mp->mp_fheight != mp->mp_aheight) {
810 unsigned int maxsize = mp->mp_fheight > 1 ?
811 sdp->sd_inptrs : sdp->sd_diptrs;
812 maxsize -= mp->mp_list[mp->mp_fheight - 1];
813 if (size > maxsize)
814 size = maxsize;
815 return size;
816 }
817
818 first = metapointer(ip->i_height - 1, mp);
819 end = metaend(ip->i_height - 1, mp);
820 if (end - first > size)
821 end = first + size;
822 for (ptr = first; ptr < end; ptr++) {
823 if (*ptr)
824 break;
825 }
826 return ptr - first;
827}
828
829/**
830 * __gfs2_iomap_get - Map blocks from an inode to disk blocks
831 * @inode: The inode
832 * @pos: Starting position in bytes
833 * @length: Length to map, in bytes
834 * @flags: iomap flags
835 * @iomap: The iomap structure
836 * @mp: The metapath
837 *
838 * Returns: errno
839 */
840static int __gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
841 unsigned flags, struct iomap *iomap,
842 struct metapath *mp)
843{
844 struct gfs2_inode *ip = GFS2_I(inode);
845 struct gfs2_sbd *sdp = GFS2_SB(inode);
846 loff_t size = i_size_read(inode);
847 __be64 *ptr;
848 sector_t lblock;
849 sector_t lblock_stop;
850 int ret;
851 int eob;
852 u64 len;
853 struct buffer_head *dibh = NULL, *bh;
854 u8 height;
855
856 if (!length)
857 return -EINVAL;
858
859 down_read(&ip->i_rw_mutex);
860
861 ret = gfs2_meta_inode_buffer(ip, &dibh);
862 if (ret)
863 goto unlock;
864 mp->mp_bh[0] = dibh;
865
866 if (gfs2_is_stuffed(ip)) {
867 if (flags & IOMAP_WRITE) {
868 loff_t max_size = gfs2_max_stuffed_size(ip);
869
870 if (pos + length > max_size)
871 goto unstuff;
872 iomap->length = max_size;
873 } else {
874 if (pos >= size) {
875 if (flags & IOMAP_REPORT) {
876 ret = -ENOENT;
877 goto unlock;
878 } else {
879 iomap->offset = pos;
880 iomap->length = length;
881 goto hole_found;
882 }
883 }
884 iomap->length = size;
885 }
886 iomap->addr = (ip->i_no_addr << inode->i_blkbits) +
887 sizeof(struct gfs2_dinode);
888 iomap->type = IOMAP_INLINE;
889 iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode);
890 goto out;
891 }
892
893unstuff:
894 lblock = pos >> inode->i_blkbits;
895 iomap->offset = lblock << inode->i_blkbits;
896 lblock_stop = (pos + length - 1) >> inode->i_blkbits;
897 len = lblock_stop - lblock + 1;
898 iomap->length = len << inode->i_blkbits;
899
900 height = ip->i_height;
901 while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])
902 height++;
903 find_metapath(sdp, lblock, mp, height);
904 if (height > ip->i_height || gfs2_is_stuffed(ip))
905 goto do_alloc;
906
907 ret = lookup_metapath(ip, mp);
908 if (ret)
909 goto unlock;
910
911 if (mp->mp_aheight != ip->i_height)
912 goto do_alloc;
913
914 ptr = metapointer(ip->i_height - 1, mp);
915 if (*ptr == 0)
916 goto do_alloc;
917
918 bh = mp->mp_bh[ip->i_height - 1];
919 len = gfs2_extent_length(bh, ptr, &eob);
920
921 iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
922 iomap->length = len << inode->i_blkbits;
923 iomap->type = IOMAP_MAPPED;
924 iomap->flags |= IOMAP_F_MERGED;
925 if (eob)
926 iomap->flags |= IOMAP_F_GFS2_BOUNDARY;
927
928out:
929 iomap->bdev = inode->i_sb->s_bdev;
930unlock:
931 up_read(&ip->i_rw_mutex);
932 return ret;
933
934do_alloc:
935 if (flags & IOMAP_REPORT) {
936 if (pos >= size)
937 ret = -ENOENT;
938 else if (height == ip->i_height)
939 ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
940 else
941 iomap->length = size - iomap->offset;
942 } else if (flags & IOMAP_WRITE) {
943 u64 alloc_size;
944
945 if (flags & IOMAP_DIRECT)
946 goto out; /* (see gfs2_file_direct_write) */
947
948 len = gfs2_alloc_size(inode, mp, len);
949 alloc_size = len << inode->i_blkbits;
950 if (alloc_size < iomap->length)
951 iomap->length = alloc_size;
952 } else {
953 if (pos < size && height == ip->i_height)
954 ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
955 }
956hole_found:
957 iomap->addr = IOMAP_NULL_ADDR;
958 iomap->type = IOMAP_HOLE;
959 goto out;
960}
961
962static struct folio *
963gfs2_iomap_get_folio(struct iomap_iter *iter, loff_t pos, unsigned len)
964{
965 struct inode *inode = iter->inode;
966 unsigned int blockmask = i_blocksize(inode) - 1;
967 struct gfs2_sbd *sdp = GFS2_SB(inode);
968 unsigned int blocks;
969 struct folio *folio;
970 int status;
971
972 blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits;
973 status = gfs2_trans_begin(sdp, RES_DINODE + blocks, 0);
974 if (status)
975 return ERR_PTR(status);
976
977 folio = iomap_get_folio(iter, pos, len);
978 if (IS_ERR(folio))
979 gfs2_trans_end(sdp);
980 return folio;
981}
982
983static void gfs2_iomap_put_folio(struct inode *inode, loff_t pos,
984 unsigned copied, struct folio *folio)
985{
986 struct gfs2_trans *tr = current->journal_info;
987 struct gfs2_inode *ip = GFS2_I(inode);
988 struct gfs2_sbd *sdp = GFS2_SB(inode);
989
990 if (!gfs2_is_stuffed(ip))
991 gfs2_trans_add_databufs(ip, folio, offset_in_folio(folio, pos),
992 copied);
993
994 folio_unlock(folio);
995 folio_put(folio);
996
997 if (tr->tr_num_buf_new)
998 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
999
1000 gfs2_trans_end(sdp);
1001}
1002
1003static const struct iomap_folio_ops gfs2_iomap_folio_ops = {
1004 .get_folio = gfs2_iomap_get_folio,
1005 .put_folio = gfs2_iomap_put_folio,
1006};
1007
1008static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos,
1009 loff_t length, unsigned flags,
1010 struct iomap *iomap,
1011 struct metapath *mp)
1012{
1013 struct gfs2_inode *ip = GFS2_I(inode);
1014 struct gfs2_sbd *sdp = GFS2_SB(inode);
1015 bool unstuff;
1016 int ret;
1017
1018 unstuff = gfs2_is_stuffed(ip) &&
1019 pos + length > gfs2_max_stuffed_size(ip);
1020
1021 if (unstuff || iomap->type == IOMAP_HOLE) {
1022 unsigned int data_blocks, ind_blocks;
1023 struct gfs2_alloc_parms ap = {};
1024 unsigned int rblocks;
1025 struct gfs2_trans *tr;
1026
1027 gfs2_write_calc_reserv(ip, iomap->length, &data_blocks,
1028 &ind_blocks);
1029 ap.target = data_blocks + ind_blocks;
1030 ret = gfs2_quota_lock_check(ip, &ap);
1031 if (ret)
1032 return ret;
1033
1034 ret = gfs2_inplace_reserve(ip, &ap);
1035 if (ret)
1036 goto out_qunlock;
1037
1038 rblocks = RES_DINODE + ind_blocks;
1039 if (gfs2_is_jdata(ip))
1040 rblocks += data_blocks;
1041 if (ind_blocks || data_blocks)
1042 rblocks += RES_STATFS + RES_QUOTA;
1043 if (inode == sdp->sd_rindex)
1044 rblocks += 2 * RES_STATFS;
1045 rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
1046
1047 ret = gfs2_trans_begin(sdp, rblocks,
1048 iomap->length >> inode->i_blkbits);
1049 if (ret)
1050 goto out_trans_fail;
1051
1052 if (unstuff) {
1053 ret = gfs2_unstuff_dinode(ip);
1054 if (ret)
1055 goto out_trans_end;
1056 release_metapath(mp);
1057 ret = __gfs2_iomap_get(inode, iomap->offset,
1058 iomap->length, flags, iomap, mp);
1059 if (ret)
1060 goto out_trans_end;
1061 }
1062
1063 if (iomap->type == IOMAP_HOLE) {
1064 ret = __gfs2_iomap_alloc(inode, iomap, mp);
1065 if (ret) {
1066 gfs2_trans_end(sdp);
1067 gfs2_inplace_release(ip);
1068 punch_hole(ip, iomap->offset, iomap->length);
1069 goto out_qunlock;
1070 }
1071 }
1072
1073 tr = current->journal_info;
1074 if (tr->tr_num_buf_new)
1075 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1076
1077 gfs2_trans_end(sdp);
1078 }
1079
1080 if (gfs2_is_stuffed(ip) || gfs2_is_jdata(ip))
1081 iomap->folio_ops = &gfs2_iomap_folio_ops;
1082 return 0;
1083
1084out_trans_end:
1085 gfs2_trans_end(sdp);
1086out_trans_fail:
1087 gfs2_inplace_release(ip);
1088out_qunlock:
1089 gfs2_quota_unlock(ip);
1090 return ret;
1091}
1092
1093static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
1094 unsigned flags, struct iomap *iomap,
1095 struct iomap *srcmap)
1096{
1097 struct gfs2_inode *ip = GFS2_I(inode);
1098 struct metapath mp = { .mp_aheight = 1, };
1099 int ret;
1100
1101 if (gfs2_is_jdata(ip))
1102 iomap->flags |= IOMAP_F_BUFFER_HEAD;
1103
1104 trace_gfs2_iomap_start(ip, pos, length, flags);
1105 ret = __gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
1106 if (ret)
1107 goto out_unlock;
1108
1109 switch(flags & (IOMAP_WRITE | IOMAP_ZERO)) {
1110 case IOMAP_WRITE:
1111 if (flags & IOMAP_DIRECT) {
1112 /*
1113 * Silently fall back to buffered I/O for stuffed files
1114 * or if we've got a hole (see gfs2_file_direct_write).
1115 */
1116 if (iomap->type != IOMAP_MAPPED)
1117 ret = -ENOTBLK;
1118 goto out_unlock;
1119 }
1120 break;
1121 case IOMAP_ZERO:
1122 if (iomap->type == IOMAP_HOLE)
1123 goto out_unlock;
1124 break;
1125 default:
1126 goto out_unlock;
1127 }
1128
1129 ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp);
1130
1131out_unlock:
1132 release_metapath(&mp);
1133 trace_gfs2_iomap_end(ip, iomap, ret);
1134 return ret;
1135}
1136
1137static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
1138 ssize_t written, unsigned flags, struct iomap *iomap)
1139{
1140 struct gfs2_inode *ip = GFS2_I(inode);
1141 struct gfs2_sbd *sdp = GFS2_SB(inode);
1142
1143 switch (flags & (IOMAP_WRITE | IOMAP_ZERO)) {
1144 case IOMAP_WRITE:
1145 if (flags & IOMAP_DIRECT)
1146 return 0;
1147 break;
1148 case IOMAP_ZERO:
1149 if (iomap->type == IOMAP_HOLE)
1150 return 0;
1151 break;
1152 default:
1153 return 0;
1154 }
1155
1156 if (!gfs2_is_stuffed(ip))
1157 gfs2_ordered_add_inode(ip);
1158
1159 if (inode == sdp->sd_rindex)
1160 adjust_fs_space(inode);
1161
1162 gfs2_inplace_release(ip);
1163
1164 if (ip->i_qadata && ip->i_qadata->qa_qd_num)
1165 gfs2_quota_unlock(ip);
1166
1167 if (length != written && (iomap->flags & IOMAP_F_NEW)) {
1168 /* Deallocate blocks that were just allocated. */
1169 loff_t hstart = round_up(pos + written, i_blocksize(inode));
1170 loff_t hend = iomap->offset + iomap->length;
1171
1172 if (hstart < hend) {
1173 truncate_pagecache_range(inode, hstart, hend - 1);
1174 punch_hole(ip, hstart, hend - hstart);
1175 }
1176 }
1177
1178 if (unlikely(!written))
1179 return 0;
1180
1181 if (iomap->flags & IOMAP_F_SIZE_CHANGED)
1182 mark_inode_dirty(inode);
1183 set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
1184 return 0;
1185}
1186
1187const struct iomap_ops gfs2_iomap_ops = {
1188 .iomap_begin = gfs2_iomap_begin,
1189 .iomap_end = gfs2_iomap_end,
1190};
1191
1192/**
1193 * gfs2_block_map - Map one or more blocks of an inode to a disk block
1194 * @inode: The inode
1195 * @lblock: The logical block number
1196 * @bh_map: The bh to be mapped
1197 * @create: True if its ok to alloc blocks to satify the request
1198 *
1199 * The size of the requested mapping is defined in bh_map->b_size.
1200 *
1201 * Clears buffer_mapped(bh_map) and leaves bh_map->b_size unchanged
1202 * when @lblock is not mapped. Sets buffer_mapped(bh_map) and
1203 * bh_map->b_size to indicate the size of the mapping when @lblock and
1204 * successive blocks are mapped, up to the requested size.
1205 *
1206 * Sets buffer_boundary() if a read of metadata will be required
1207 * before the next block can be mapped. Sets buffer_new() if new
1208 * blocks were allocated.
1209 *
1210 * Returns: errno
1211 */
1212
1213int gfs2_block_map(struct inode *inode, sector_t lblock,
1214 struct buffer_head *bh_map, int create)
1215{
1216 struct gfs2_inode *ip = GFS2_I(inode);
1217 loff_t pos = (loff_t)lblock << inode->i_blkbits;
1218 loff_t length = bh_map->b_size;
1219 struct iomap iomap = { };
1220 int ret;
1221
1222 clear_buffer_mapped(bh_map);
1223 clear_buffer_new(bh_map);
1224 clear_buffer_boundary(bh_map);
1225 trace_gfs2_bmap(ip, bh_map, lblock, create, 1);
1226
1227 if (!create)
1228 ret = gfs2_iomap_get(inode, pos, length, &iomap);
1229 else
1230 ret = gfs2_iomap_alloc(inode, pos, length, &iomap);
1231 if (ret)
1232 goto out;
1233
1234 if (iomap.length > bh_map->b_size) {
1235 iomap.length = bh_map->b_size;
1236 iomap.flags &= ~IOMAP_F_GFS2_BOUNDARY;
1237 }
1238 if (iomap.addr != IOMAP_NULL_ADDR)
1239 map_bh(bh_map, inode->i_sb, iomap.addr >> inode->i_blkbits);
1240 bh_map->b_size = iomap.length;
1241 if (iomap.flags & IOMAP_F_GFS2_BOUNDARY)
1242 set_buffer_boundary(bh_map);
1243 if (iomap.flags & IOMAP_F_NEW)
1244 set_buffer_new(bh_map);
1245
1246out:
1247 trace_gfs2_bmap(ip, bh_map, lblock, create, ret);
1248 return ret;
1249}
1250
1251int gfs2_get_extent(struct inode *inode, u64 lblock, u64 *dblock,
1252 unsigned int *extlen)
1253{
1254 unsigned int blkbits = inode->i_blkbits;
1255 struct iomap iomap = { };
1256 unsigned int len;
1257 int ret;
1258
1259 ret = gfs2_iomap_get(inode, lblock << blkbits, *extlen << blkbits,
1260 &iomap);
1261 if (ret)
1262 return ret;
1263 if (iomap.type != IOMAP_MAPPED)
1264 return -EIO;
1265 *dblock = iomap.addr >> blkbits;
1266 len = iomap.length >> blkbits;
1267 if (len < *extlen)
1268 *extlen = len;
1269 return 0;
1270}
1271
1272int gfs2_alloc_extent(struct inode *inode, u64 lblock, u64 *dblock,
1273 unsigned int *extlen, bool *new)
1274{
1275 unsigned int blkbits = inode->i_blkbits;
1276 struct iomap iomap = { };
1277 unsigned int len;
1278 int ret;
1279
1280 ret = gfs2_iomap_alloc(inode, lblock << blkbits, *extlen << blkbits,
1281 &iomap);
1282 if (ret)
1283 return ret;
1284 if (iomap.type != IOMAP_MAPPED)
1285 return -EIO;
1286 *dblock = iomap.addr >> blkbits;
1287 len = iomap.length >> blkbits;
1288 if (len < *extlen)
1289 *extlen = len;
1290 *new = iomap.flags & IOMAP_F_NEW;
1291 return 0;
1292}
1293
1294/*
1295 * NOTE: Never call gfs2_block_zero_range with an open transaction because it
1296 * uses iomap write to perform its actions, which begin their own transactions
1297 * (iomap_begin, get_folio, etc.)
1298 */
1299static int gfs2_block_zero_range(struct inode *inode, loff_t from,
1300 unsigned int length)
1301{
1302 BUG_ON(current->journal_info);
1303 return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops);
1304}
1305
1306#define GFS2_JTRUNC_REVOKES 8192
1307
1308/**
1309 * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files
1310 * @inode: The inode being truncated
1311 * @oldsize: The original (larger) size
1312 * @newsize: The new smaller size
1313 *
1314 * With jdata files, we have to journal a revoke for each block which is
1315 * truncated. As a result, we need to split this into separate transactions
1316 * if the number of pages being truncated gets too large.
1317 */
1318
1319static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize)
1320{
1321 struct gfs2_sbd *sdp = GFS2_SB(inode);
1322 u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
1323 u64 chunk;
1324 int error;
1325
1326 while (oldsize != newsize) {
1327 struct gfs2_trans *tr;
1328 unsigned int offs;
1329
1330 chunk = oldsize - newsize;
1331 if (chunk > max_chunk)
1332 chunk = max_chunk;
1333
1334 offs = oldsize & ~PAGE_MASK;
1335 if (offs && chunk > PAGE_SIZE)
1336 chunk = offs + ((chunk - offs) & PAGE_MASK);
1337
1338 truncate_pagecache(inode, oldsize - chunk);
1339 oldsize -= chunk;
1340
1341 tr = current->journal_info;
1342 if (!test_bit(TR_TOUCHED, &tr->tr_flags))
1343 continue;
1344
1345 gfs2_trans_end(sdp);
1346 error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
1347 if (error)
1348 return error;
1349 }
1350
1351 return 0;
1352}
1353
1354static int trunc_start(struct inode *inode, u64 newsize)
1355{
1356 struct gfs2_inode *ip = GFS2_I(inode);
1357 struct gfs2_sbd *sdp = GFS2_SB(inode);
1358 struct buffer_head *dibh = NULL;
1359 int journaled = gfs2_is_jdata(ip);
1360 u64 oldsize = inode->i_size;
1361 int error;
1362
1363 if (!gfs2_is_stuffed(ip)) {
1364 unsigned int blocksize = i_blocksize(inode);
1365 unsigned int offs = newsize & (blocksize - 1);
1366 if (offs) {
1367 error = gfs2_block_zero_range(inode, newsize,
1368 blocksize - offs);
1369 if (error)
1370 return error;
1371 }
1372 }
1373 if (journaled)
1374 error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES);
1375 else
1376 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1377 if (error)
1378 return error;
1379
1380 error = gfs2_meta_inode_buffer(ip, &dibh);
1381 if (error)
1382 goto out;
1383
1384 gfs2_trans_add_meta(ip->i_gl, dibh);
1385
1386 if (gfs2_is_stuffed(ip))
1387 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize);
1388 else
1389 ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG;
1390
1391 i_size_write(inode, newsize);
1392 inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1393 gfs2_dinode_out(ip, dibh->b_data);
1394
1395 if (journaled)
1396 error = gfs2_journaled_truncate(inode, oldsize, newsize);
1397 else
1398 truncate_pagecache(inode, newsize);
1399
1400out:
1401 brelse(dibh);
1402 if (current->journal_info)
1403 gfs2_trans_end(sdp);
1404 return error;
1405}
1406
1407int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
1408 struct iomap *iomap)
1409{
1410 struct metapath mp = { .mp_aheight = 1, };
1411 int ret;
1412
1413 ret = __gfs2_iomap_get(inode, pos, length, 0, iomap, &mp);
1414 release_metapath(&mp);
1415 return ret;
1416}
1417
1418int gfs2_iomap_alloc(struct inode *inode, loff_t pos, loff_t length,
1419 struct iomap *iomap)
1420{
1421 struct metapath mp = { .mp_aheight = 1, };
1422 int ret;
1423
1424 ret = __gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, iomap, &mp);
1425 if (!ret && iomap->type == IOMAP_HOLE)
1426 ret = __gfs2_iomap_alloc(inode, iomap, &mp);
1427 release_metapath(&mp);
1428 return ret;
1429}
1430
1431/**
1432 * sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein
1433 * @ip: inode
1434 * @rd_gh: holder of resource group glock
1435 * @bh: buffer head to sweep
1436 * @start: starting point in bh
1437 * @end: end point in bh
1438 * @meta: true if bh points to metadata (rather than data)
1439 * @btotal: place to keep count of total blocks freed
1440 *
1441 * We sweep a metadata buffer (provided by the metapath) for blocks we need to
1442 * free, and free them all. However, we do it one rgrp at a time. If this
1443 * block has references to multiple rgrps, we break it into individual
1444 * transactions. This allows other processes to use the rgrps while we're
1445 * focused on a single one, for better concurrency / performance.
1446 * At every transaction boundary, we rewrite the inode into the journal.
1447 * That way the bitmaps are kept consistent with the inode and we can recover
1448 * if we're interrupted by power-outages.
1449 *
1450 * Returns: 0, or return code if an error occurred.
1451 * *btotal has the total number of blocks freed
1452 */
1453static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh,
1454 struct buffer_head *bh, __be64 *start, __be64 *end,
1455 bool meta, u32 *btotal)
1456{
1457 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1458 struct gfs2_rgrpd *rgd;
1459 struct gfs2_trans *tr;
1460 __be64 *p;
1461 int blks_outside_rgrp;
1462 u64 bn, bstart, isize_blks;
1463 s64 blen; /* needs to be s64 or gfs2_add_inode_blocks breaks */
1464 int ret = 0;
1465 bool buf_in_tr = false; /* buffer was added to transaction */
1466
1467more_rgrps:
1468 rgd = NULL;
1469 if (gfs2_holder_initialized(rd_gh)) {
1470 rgd = gfs2_glock2rgrp(rd_gh->gh_gl);
1471 gfs2_assert_withdraw(sdp,
1472 gfs2_glock_is_locked_by_me(rd_gh->gh_gl));
1473 }
1474 blks_outside_rgrp = 0;
1475 bstart = 0;
1476 blen = 0;
1477
1478 for (p = start; p < end; p++) {
1479 if (!*p)
1480 continue;
1481 bn = be64_to_cpu(*p);
1482
1483 if (rgd) {
1484 if (!rgrp_contains_block(rgd, bn)) {
1485 blks_outside_rgrp++;
1486 continue;
1487 }
1488 } else {
1489 rgd = gfs2_blk2rgrpd(sdp, bn, true);
1490 if (unlikely(!rgd)) {
1491 ret = -EIO;
1492 goto out;
1493 }
1494 ret = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
1495 LM_FLAG_NODE_SCOPE, rd_gh);
1496 if (ret)
1497 goto out;
1498
1499 /* Must be done with the rgrp glock held: */
1500 if (gfs2_rs_active(&ip->i_res) &&
1501 rgd == ip->i_res.rs_rgd)
1502 gfs2_rs_deltree(&ip->i_res);
1503 }
1504
1505 /* The size of our transactions will be unknown until we
1506 actually process all the metadata blocks that relate to
1507 the rgrp. So we estimate. We know it can't be more than
1508 the dinode's i_blocks and we don't want to exceed the
1509 journal flush threshold, sd_log_thresh2. */
1510 if (current->journal_info == NULL) {
1511 unsigned int jblocks_rqsted, revokes;
1512
1513 jblocks_rqsted = rgd->rd_length + RES_DINODE +
1514 RES_INDIRECT;
1515 isize_blks = gfs2_get_inode_blocks(&ip->i_inode);
1516 if (isize_blks > atomic_read(&sdp->sd_log_thresh2))
1517 jblocks_rqsted +=
1518 atomic_read(&sdp->sd_log_thresh2);
1519 else
1520 jblocks_rqsted += isize_blks;
1521 revokes = jblocks_rqsted;
1522 if (meta)
1523 revokes += end - start;
1524 else if (ip->i_depth)
1525 revokes += sdp->sd_inptrs;
1526 ret = gfs2_trans_begin(sdp, jblocks_rqsted, revokes);
1527 if (ret)
1528 goto out_unlock;
1529 down_write(&ip->i_rw_mutex);
1530 }
1531 /* check if we will exceed the transaction blocks requested */
1532 tr = current->journal_info;
1533 if (tr->tr_num_buf_new + RES_STATFS +
1534 RES_QUOTA >= atomic_read(&sdp->sd_log_thresh2)) {
1535 /* We set blks_outside_rgrp to ensure the loop will
1536 be repeated for the same rgrp, but with a new
1537 transaction. */
1538 blks_outside_rgrp++;
1539 /* This next part is tricky. If the buffer was added
1540 to the transaction, we've already set some block
1541 pointers to 0, so we better follow through and free
1542 them, or we will introduce corruption (so break).
1543 This may be impossible, or at least rare, but I
1544 decided to cover the case regardless.
1545
1546 If the buffer was not added to the transaction
1547 (this call), doing so would exceed our transaction
1548 size, so we need to end the transaction and start a
1549 new one (so goto). */
1550
1551 if (buf_in_tr)
1552 break;
1553 goto out_unlock;
1554 }
1555
1556 gfs2_trans_add_meta(ip->i_gl, bh);
1557 buf_in_tr = true;
1558 *p = 0;
1559 if (bstart + blen == bn) {
1560 blen++;
1561 continue;
1562 }
1563 if (bstart) {
1564 __gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta);
1565 (*btotal) += blen;
1566 gfs2_add_inode_blocks(&ip->i_inode, -blen);
1567 }
1568 bstart = bn;
1569 blen = 1;
1570 }
1571 if (bstart) {
1572 __gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta);
1573 (*btotal) += blen;
1574 gfs2_add_inode_blocks(&ip->i_inode, -blen);
1575 }
1576out_unlock:
1577 if (!ret && blks_outside_rgrp) { /* If buffer still has non-zero blocks
1578 outside the rgrp we just processed,
1579 do it all over again. */
1580 if (current->journal_info) {
1581 struct buffer_head *dibh;
1582
1583 ret = gfs2_meta_inode_buffer(ip, &dibh);
1584 if (ret)
1585 goto out;
1586
1587 /* Every transaction boundary, we rewrite the dinode
1588 to keep its di_blocks current in case of failure. */
1589 inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1590 gfs2_trans_add_meta(ip->i_gl, dibh);
1591 gfs2_dinode_out(ip, dibh->b_data);
1592 brelse(dibh);
1593 up_write(&ip->i_rw_mutex);
1594 gfs2_trans_end(sdp);
1595 buf_in_tr = false;
1596 }
1597 gfs2_glock_dq_uninit(rd_gh);
1598 cond_resched();
1599 goto more_rgrps;
1600 }
1601out:
1602 return ret;
1603}
1604
1605static bool mp_eq_to_hgt(struct metapath *mp, __u16 *list, unsigned int h)
1606{
1607 if (memcmp(mp->mp_list, list, h * sizeof(mp->mp_list[0])))
1608 return false;
1609 return true;
1610}
1611
1612/**
1613 * find_nonnull_ptr - find a non-null pointer given a metapath and height
1614 * @sdp: The superblock
1615 * @mp: starting metapath
1616 * @h: desired height to search
1617 * @end_list: See punch_hole().
1618 * @end_aligned: See punch_hole().
1619 *
1620 * Assumes the metapath is valid (with buffers) out to height h.
1621 * Returns: true if a non-null pointer was found in the metapath buffer
1622 * false if all remaining pointers are NULL in the buffer
1623 */
1624static bool find_nonnull_ptr(struct gfs2_sbd *sdp, struct metapath *mp,
1625 unsigned int h,
1626 __u16 *end_list, unsigned int end_aligned)
1627{
1628 struct buffer_head *bh = mp->mp_bh[h];
1629 __be64 *first, *ptr, *end;
1630
1631 first = metaptr1(h, mp);
1632 ptr = first + mp->mp_list[h];
1633 end = (__be64 *)(bh->b_data + bh->b_size);
1634 if (end_list && mp_eq_to_hgt(mp, end_list, h)) {
1635 bool keep_end = h < end_aligned;
1636 end = first + end_list[h] + keep_end;
1637 }
1638
1639 while (ptr < end) {
1640 if (*ptr) { /* if we have a non-null pointer */
1641 mp->mp_list[h] = ptr - first;
1642 h++;
1643 if (h < GFS2_MAX_META_HEIGHT)
1644 mp->mp_list[h] = 0;
1645 return true;
1646 }
1647 ptr++;
1648 }
1649 return false;
1650}
1651
1652enum dealloc_states {
1653 DEALLOC_MP_FULL = 0, /* Strip a metapath with all buffers read in */
1654 DEALLOC_MP_LOWER = 1, /* lower the metapath strip height */
1655 DEALLOC_FILL_MP = 2, /* Fill in the metapath to the given height. */
1656 DEALLOC_DONE = 3, /* process complete */
1657};
1658
1659static inline void
1660metapointer_range(struct metapath *mp, int height,
1661 __u16 *start_list, unsigned int start_aligned,
1662 __u16 *end_list, unsigned int end_aligned,
1663 __be64 **start, __be64 **end)
1664{
1665 struct buffer_head *bh = mp->mp_bh[height];
1666 __be64 *first;
1667
1668 first = metaptr1(height, mp);
1669 *start = first;
1670 if (mp_eq_to_hgt(mp, start_list, height)) {
1671 bool keep_start = height < start_aligned;
1672 *start = first + start_list[height] + keep_start;
1673 }
1674 *end = (__be64 *)(bh->b_data + bh->b_size);
1675 if (end_list && mp_eq_to_hgt(mp, end_list, height)) {
1676 bool keep_end = height < end_aligned;
1677 *end = first + end_list[height] + keep_end;
1678 }
1679}
1680
1681static inline bool walk_done(struct gfs2_sbd *sdp,
1682 struct metapath *mp, int height,
1683 __u16 *end_list, unsigned int end_aligned)
1684{
1685 __u16 end;
1686
1687 if (end_list) {
1688 bool keep_end = height < end_aligned;
1689 if (!mp_eq_to_hgt(mp, end_list, height))
1690 return false;
1691 end = end_list[height] + keep_end;
1692 } else
1693 end = (height > 0) ? sdp->sd_inptrs : sdp->sd_diptrs;
1694 return mp->mp_list[height] >= end;
1695}
1696
1697/**
1698 * punch_hole - deallocate blocks in a file
1699 * @ip: inode to truncate
1700 * @offset: the start of the hole
1701 * @length: the size of the hole (or 0 for truncate)
1702 *
1703 * Punch a hole into a file or truncate a file at a given position. This
1704 * function operates in whole blocks (@offset and @length are rounded
1705 * accordingly); partially filled blocks must be cleared otherwise.
1706 *
1707 * This function works from the bottom up, and from the right to the left. In
1708 * other words, it strips off the highest layer (data) before stripping any of
1709 * the metadata. Doing it this way is best in case the operation is interrupted
1710 * by power failure, etc. The dinode is rewritten in every transaction to
1711 * guarantee integrity.
1712 */
1713static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
1714{
1715 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1716 u64 maxsize = sdp->sd_heightsize[ip->i_height];
1717 struct metapath mp = {};
1718 struct buffer_head *dibh, *bh;
1719 struct gfs2_holder rd_gh;
1720 unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift;
1721 unsigned int bsize = 1 << bsize_shift;
1722 u64 lblock = (offset + bsize - 1) >> bsize_shift;
1723 __u16 start_list[GFS2_MAX_META_HEIGHT];
1724 __u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL;
1725 unsigned int start_aligned, end_aligned;
1726 unsigned int strip_h = ip->i_height - 1;
1727 u32 btotal = 0;
1728 int ret, state;
1729 int mp_h; /* metapath buffers are read in to this height */
1730 u64 prev_bnr = 0;
1731 __be64 *start, *end;
1732
1733 if (offset + bsize - 1 >= maxsize) {
1734 /*
1735 * The starting point lies beyond the allocated metadata;
1736 * there are no blocks to deallocate.
1737 */
1738 return 0;
1739 }
1740
1741 /*
1742 * The start position of the hole is defined by lblock, start_list, and
1743 * start_aligned. The end position of the hole is defined by lend,
1744 * end_list, and end_aligned.
1745 *
1746 * start_aligned and end_aligned define down to which height the start
1747 * and end positions are aligned to the metadata tree (i.e., the
1748 * position is a multiple of the metadata granularity at the height
1749 * above). This determines at which heights additional meta pointers
1750 * needs to be preserved for the remaining data.
1751 */
1752
1753 if (length) {
1754 u64 end_offset = offset + length;
1755 u64 lend;
1756
1757 /*
1758 * Clip the end at the maximum file size for the given height:
1759 * that's how far the metadata goes; files bigger than that
1760 * will have additional layers of indirection.
1761 */
1762 if (end_offset > maxsize)
1763 end_offset = maxsize;
1764 lend = end_offset >> bsize_shift;
1765
1766 if (lblock >= lend)
1767 return 0;
1768
1769 find_metapath(sdp, lend, &mp, ip->i_height);
1770 end_list = __end_list;
1771 memcpy(end_list, mp.mp_list, sizeof(mp.mp_list));
1772
1773 for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) {
1774 if (end_list[mp_h])
1775 break;
1776 }
1777 end_aligned = mp_h;
1778 }
1779
1780 find_metapath(sdp, lblock, &mp, ip->i_height);
1781 memcpy(start_list, mp.mp_list, sizeof(start_list));
1782
1783 for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) {
1784 if (start_list[mp_h])
1785 break;
1786 }
1787 start_aligned = mp_h;
1788
1789 ret = gfs2_meta_inode_buffer(ip, &dibh);
1790 if (ret)
1791 return ret;
1792
1793 mp.mp_bh[0] = dibh;
1794 ret = lookup_metapath(ip, &mp);
1795 if (ret)
1796 goto out_metapath;
1797
1798 /* issue read-ahead on metadata */
1799 for (mp_h = 0; mp_h < mp.mp_aheight - 1; mp_h++) {
1800 metapointer_range(&mp, mp_h, start_list, start_aligned,
1801 end_list, end_aligned, &start, &end);
1802 gfs2_metapath_ra(ip->i_gl, start, end);
1803 }
1804
1805 if (mp.mp_aheight == ip->i_height)
1806 state = DEALLOC_MP_FULL; /* We have a complete metapath */
1807 else
1808 state = DEALLOC_FILL_MP; /* deal with partial metapath */
1809
1810 ret = gfs2_rindex_update(sdp);
1811 if (ret)
1812 goto out_metapath;
1813
1814 ret = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1815 if (ret)
1816 goto out_metapath;
1817 gfs2_holder_mark_uninitialized(&rd_gh);
1818
1819 mp_h = strip_h;
1820
1821 while (state != DEALLOC_DONE) {
1822 switch (state) {
1823 /* Truncate a full metapath at the given strip height.
1824 * Note that strip_h == mp_h in order to be in this state. */
1825 case DEALLOC_MP_FULL:
1826 bh = mp.mp_bh[mp_h];
1827 gfs2_assert_withdraw(sdp, bh);
1828 if (gfs2_assert_withdraw(sdp,
1829 prev_bnr != bh->b_blocknr)) {
1830 fs_emerg(sdp, "inode %llu, block:%llu, i_h:%u, "
1831 "s_h:%u, mp_h:%u\n",
1832 (unsigned long long)ip->i_no_addr,
1833 prev_bnr, ip->i_height, strip_h, mp_h);
1834 }
1835 prev_bnr = bh->b_blocknr;
1836
1837 if (gfs2_metatype_check(sdp, bh,
1838 (mp_h ? GFS2_METATYPE_IN :
1839 GFS2_METATYPE_DI))) {
1840 ret = -EIO;
1841 goto out;
1842 }
1843
1844 /*
1845 * Below, passing end_aligned as 0 gives us the
1846 * metapointer range excluding the end point: the end
1847 * point is the first metapath we must not deallocate!
1848 */
1849
1850 metapointer_range(&mp, mp_h, start_list, start_aligned,
1851 end_list, 0 /* end_aligned */,
1852 &start, &end);
1853 ret = sweep_bh_for_rgrps(ip, &rd_gh, mp.mp_bh[mp_h],
1854 start, end,
1855 mp_h != ip->i_height - 1,
1856 &btotal);
1857
1858 /* If we hit an error or just swept dinode buffer,
1859 just exit. */
1860 if (ret || !mp_h) {
1861 state = DEALLOC_DONE;
1862 break;
1863 }
1864 state = DEALLOC_MP_LOWER;
1865 break;
1866
1867 /* lower the metapath strip height */
1868 case DEALLOC_MP_LOWER:
1869 /* We're done with the current buffer, so release it,
1870 unless it's the dinode buffer. Then back up to the
1871 previous pointer. */
1872 if (mp_h) {
1873 brelse(mp.mp_bh[mp_h]);
1874 mp.mp_bh[mp_h] = NULL;
1875 }
1876 /* If we can't get any lower in height, we've stripped
1877 off all we can. Next step is to back up and start
1878 stripping the previous level of metadata. */
1879 if (mp_h == 0) {
1880 strip_h--;
1881 memcpy(mp.mp_list, start_list, sizeof(start_list));
1882 mp_h = strip_h;
1883 state = DEALLOC_FILL_MP;
1884 break;
1885 }
1886 mp.mp_list[mp_h] = 0;
1887 mp_h--; /* search one metadata height down */
1888 mp.mp_list[mp_h]++;
1889 if (walk_done(sdp, &mp, mp_h, end_list, end_aligned))
1890 break;
1891 /* Here we've found a part of the metapath that is not
1892 * allocated. We need to search at that height for the
1893 * next non-null pointer. */
1894 if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned)) {
1895 state = DEALLOC_FILL_MP;
1896 mp_h++;
1897 }
1898 /* No more non-null pointers at this height. Back up
1899 to the previous height and try again. */
1900 break; /* loop around in the same state */
1901
1902 /* Fill the metapath with buffers to the given height. */
1903 case DEALLOC_FILL_MP:
1904 /* Fill the buffers out to the current height. */
1905 ret = fillup_metapath(ip, &mp, mp_h);
1906 if (ret < 0)
1907 goto out;
1908
1909 /* On the first pass, issue read-ahead on metadata. */
1910 if (mp.mp_aheight > 1 && strip_h == ip->i_height - 1) {
1911 unsigned int height = mp.mp_aheight - 1;
1912
1913 /* No read-ahead for data blocks. */
1914 if (mp.mp_aheight - 1 == strip_h)
1915 height--;
1916
1917 for (; height >= mp.mp_aheight - ret; height--) {
1918 metapointer_range(&mp, height,
1919 start_list, start_aligned,
1920 end_list, end_aligned,
1921 &start, &end);
1922 gfs2_metapath_ra(ip->i_gl, start, end);
1923 }
1924 }
1925
1926 /* If buffers found for the entire strip height */
1927 if (mp.mp_aheight - 1 == strip_h) {
1928 state = DEALLOC_MP_FULL;
1929 break;
1930 }
1931 if (mp.mp_aheight < ip->i_height) /* We have a partial height */
1932 mp_h = mp.mp_aheight - 1;
1933
1934 /* If we find a non-null block pointer, crawl a bit
1935 higher up in the metapath and try again, otherwise
1936 we need to look lower for a new starting point. */
1937 if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned))
1938 mp_h++;
1939 else
1940 state = DEALLOC_MP_LOWER;
1941 break;
1942 }
1943 }
1944
1945 if (btotal) {
1946 if (current->journal_info == NULL) {
1947 ret = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS +
1948 RES_QUOTA, 0);
1949 if (ret)
1950 goto out;
1951 down_write(&ip->i_rw_mutex);
1952 }
1953 gfs2_statfs_change(sdp, 0, +btotal, 0);
1954 gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
1955 ip->i_inode.i_gid);
1956 inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1957 gfs2_trans_add_meta(ip->i_gl, dibh);
1958 gfs2_dinode_out(ip, dibh->b_data);
1959 up_write(&ip->i_rw_mutex);
1960 gfs2_trans_end(sdp);
1961 }
1962
1963out:
1964 if (gfs2_holder_initialized(&rd_gh))
1965 gfs2_glock_dq_uninit(&rd_gh);
1966 if (current->journal_info) {
1967 up_write(&ip->i_rw_mutex);
1968 gfs2_trans_end(sdp);
1969 cond_resched();
1970 }
1971 gfs2_quota_unhold(ip);
1972out_metapath:
1973 release_metapath(&mp);
1974 return ret;
1975}
1976
1977static int trunc_end(struct gfs2_inode *ip)
1978{
1979 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1980 struct buffer_head *dibh;
1981 int error;
1982
1983 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1984 if (error)
1985 return error;
1986
1987 down_write(&ip->i_rw_mutex);
1988
1989 error = gfs2_meta_inode_buffer(ip, &dibh);
1990 if (error)
1991 goto out;
1992
1993 if (!i_size_read(&ip->i_inode)) {
1994 ip->i_height = 0;
1995 ip->i_goal = ip->i_no_addr;
1996 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
1997 gfs2_ordered_del_inode(ip);
1998 }
1999 inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
2000 ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG;
2001
2002 gfs2_trans_add_meta(ip->i_gl, dibh);
2003 gfs2_dinode_out(ip, dibh->b_data);
2004 brelse(dibh);
2005
2006out:
2007 up_write(&ip->i_rw_mutex);
2008 gfs2_trans_end(sdp);
2009 return error;
2010}
2011
2012/**
2013 * do_shrink - make a file smaller
2014 * @inode: the inode
2015 * @newsize: the size to make the file
2016 *
2017 * Called with an exclusive lock on @inode. The @size must
2018 * be equal to or smaller than the current inode size.
2019 *
2020 * Returns: errno
2021 */
2022
2023static int do_shrink(struct inode *inode, u64 newsize)
2024{
2025 struct gfs2_inode *ip = GFS2_I(inode);
2026 int error;
2027
2028 error = trunc_start(inode, newsize);
2029 if (error < 0)
2030 return error;
2031 if (gfs2_is_stuffed(ip))
2032 return 0;
2033
2034 error = punch_hole(ip, newsize, 0);
2035 if (error == 0)
2036 error = trunc_end(ip);
2037
2038 return error;
2039}
2040
2041/**
2042 * do_grow - Touch and update inode size
2043 * @inode: The inode
2044 * @size: The new size
2045 *
2046 * This function updates the timestamps on the inode and
2047 * may also increase the size of the inode. This function
2048 * must not be called with @size any smaller than the current
2049 * inode size.
2050 *
2051 * Although it is not strictly required to unstuff files here,
2052 * earlier versions of GFS2 have a bug in the stuffed file reading
2053 * code which will result in a buffer overrun if the size is larger
2054 * than the max stuffed file size. In order to prevent this from
2055 * occurring, such files are unstuffed, but in other cases we can
2056 * just update the inode size directly.
2057 *
2058 * Returns: 0 on success, or -ve on error
2059 */
2060
2061static int do_grow(struct inode *inode, u64 size)
2062{
2063 struct gfs2_inode *ip = GFS2_I(inode);
2064 struct gfs2_sbd *sdp = GFS2_SB(inode);
2065 struct gfs2_alloc_parms ap = { .target = 1, };
2066 struct buffer_head *dibh;
2067 int error;
2068 int unstuff = 0;
2069
2070 if (gfs2_is_stuffed(ip) && size > gfs2_max_stuffed_size(ip)) {
2071 error = gfs2_quota_lock_check(ip, &ap);
2072 if (error)
2073 return error;
2074
2075 error = gfs2_inplace_reserve(ip, &ap);
2076 if (error)
2077 goto do_grow_qunlock;
2078 unstuff = 1;
2079 }
2080
2081 error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT +
2082 (unstuff &&
2083 gfs2_is_jdata(ip) ? RES_JDATA : 0) +
2084 (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF ?
2085 0 : RES_QUOTA), 0);
2086 if (error)
2087 goto do_grow_release;
2088
2089 if (unstuff) {
2090 error = gfs2_unstuff_dinode(ip);
2091 if (error)
2092 goto do_end_trans;
2093 }
2094
2095 error = gfs2_meta_inode_buffer(ip, &dibh);
2096 if (error)
2097 goto do_end_trans;
2098
2099 truncate_setsize(inode, size);
2100 inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
2101 gfs2_trans_add_meta(ip->i_gl, dibh);
2102 gfs2_dinode_out(ip, dibh->b_data);
2103 brelse(dibh);
2104
2105do_end_trans:
2106 gfs2_trans_end(sdp);
2107do_grow_release:
2108 if (unstuff) {
2109 gfs2_inplace_release(ip);
2110do_grow_qunlock:
2111 gfs2_quota_unlock(ip);
2112 }
2113 return error;
2114}
2115
2116/**
2117 * gfs2_setattr_size - make a file a given size
2118 * @inode: the inode
2119 * @newsize: the size to make the file
2120 *
2121 * The file size can grow, shrink, or stay the same size. This
2122 * is called holding i_rwsem and an exclusive glock on the inode
2123 * in question.
2124 *
2125 * Returns: errno
2126 */
2127
2128int gfs2_setattr_size(struct inode *inode, u64 newsize)
2129{
2130 struct gfs2_inode *ip = GFS2_I(inode);
2131 int ret;
2132
2133 BUG_ON(!S_ISREG(inode->i_mode));
2134
2135 ret = inode_newsize_ok(inode, newsize);
2136 if (ret)
2137 return ret;
2138
2139 inode_dio_wait(inode);
2140
2141 ret = gfs2_qa_get(ip);
2142 if (ret)
2143 goto out;
2144
2145 if (newsize >= inode->i_size) {
2146 ret = do_grow(inode, newsize);
2147 goto out;
2148 }
2149
2150 ret = do_shrink(inode, newsize);
2151out:
2152 gfs2_rs_delete(ip);
2153 gfs2_qa_put(ip);
2154 return ret;
2155}
2156
2157int gfs2_truncatei_resume(struct gfs2_inode *ip)
2158{
2159 int error;
2160 error = punch_hole(ip, i_size_read(&ip->i_inode), 0);
2161 if (!error)
2162 error = trunc_end(ip);
2163 return error;
2164}
2165
2166int gfs2_file_dealloc(struct gfs2_inode *ip)
2167{
2168 return punch_hole(ip, 0, 0);
2169}
2170
2171/**
2172 * gfs2_free_journal_extents - Free cached journal bmap info
2173 * @jd: The journal
2174 *
2175 */
2176
2177void gfs2_free_journal_extents(struct gfs2_jdesc *jd)
2178{
2179 struct gfs2_journal_extent *jext;
2180
2181 while(!list_empty(&jd->extent_list)) {
2182 jext = list_first_entry(&jd->extent_list, struct gfs2_journal_extent, list);
2183 list_del(&jext->list);
2184 kfree(jext);
2185 }
2186}
2187
2188/**
2189 * gfs2_add_jextent - Add or merge a new extent to extent cache
2190 * @jd: The journal descriptor
2191 * @lblock: The logical block at start of new extent
2192 * @dblock: The physical block at start of new extent
2193 * @blocks: Size of extent in fs blocks
2194 *
2195 * Returns: 0 on success or -ENOMEM
2196 */
2197
2198static int gfs2_add_jextent(struct gfs2_jdesc *jd, u64 lblock, u64 dblock, u64 blocks)
2199{
2200 struct gfs2_journal_extent *jext;
2201
2202 if (!list_empty(&jd->extent_list)) {
2203 jext = list_last_entry(&jd->extent_list, struct gfs2_journal_extent, list);
2204 if ((jext->dblock + jext->blocks) == dblock) {
2205 jext->blocks += blocks;
2206 return 0;
2207 }
2208 }
2209
2210 jext = kzalloc(sizeof(struct gfs2_journal_extent), GFP_NOFS);
2211 if (jext == NULL)
2212 return -ENOMEM;
2213 jext->dblock = dblock;
2214 jext->lblock = lblock;
2215 jext->blocks = blocks;
2216 list_add_tail(&jext->list, &jd->extent_list);
2217 jd->nr_extents++;
2218 return 0;
2219}
2220
2221/**
2222 * gfs2_map_journal_extents - Cache journal bmap info
2223 * @sdp: The super block
2224 * @jd: The journal to map
2225 *
2226 * Create a reusable "extent" mapping from all logical
2227 * blocks to all physical blocks for the given journal. This will save
2228 * us time when writing journal blocks. Most journals will have only one
2229 * extent that maps all their logical blocks. That's because gfs2.mkfs
2230 * arranges the journal blocks sequentially to maximize performance.
2231 * So the extent would map the first block for the entire file length.
2232 * However, gfs2_jadd can happen while file activity is happening, so
2233 * those journals may not be sequential. Less likely is the case where
2234 * the users created their own journals by mounting the metafs and
2235 * laying it out. But it's still possible. These journals might have
2236 * several extents.
2237 *
2238 * Returns: 0 on success, or error on failure
2239 */
2240
2241int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
2242{
2243 u64 lblock = 0;
2244 u64 lblock_stop;
2245 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
2246 struct buffer_head bh;
2247 unsigned int shift = sdp->sd_sb.sb_bsize_shift;
2248 u64 size;
2249 int rc;
2250 ktime_t start, end;
2251
2252 start = ktime_get();
2253 lblock_stop = i_size_read(jd->jd_inode) >> shift;
2254 size = (lblock_stop - lblock) << shift;
2255 jd->nr_extents = 0;
2256 WARN_ON(!list_empty(&jd->extent_list));
2257
2258 do {
2259 bh.b_state = 0;
2260 bh.b_blocknr = 0;
2261 bh.b_size = size;
2262 rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
2263 if (rc || !buffer_mapped(&bh))
2264 goto fail;
2265 rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
2266 if (rc)
2267 goto fail;
2268 size -= bh.b_size;
2269 lblock += (bh.b_size >> ip->i_inode.i_blkbits);
2270 } while(size > 0);
2271
2272 end = ktime_get();
2273 fs_info(sdp, "journal %d mapped with %u extents in %lldms\n", jd->jd_jid,
2274 jd->nr_extents, ktime_ms_delta(end, start));
2275 return 0;
2276
2277fail:
2278 fs_warn(sdp, "error %d mapping journal %u at offset %llu (extent %u)\n",
2279 rc, jd->jd_jid,
2280 (unsigned long long)(i_size_read(jd->jd_inode) - size),
2281 jd->nr_extents);
2282 fs_warn(sdp, "bmap=%d lblock=%llu block=%llu, state=0x%08lx, size=%llu\n",
2283 rc, (unsigned long long)lblock, (unsigned long long)bh.b_blocknr,
2284 bh.b_state, (unsigned long long)bh.b_size);
2285 gfs2_free_journal_extents(jd);
2286 return rc;
2287}
2288
2289/**
2290 * gfs2_write_alloc_required - figure out if a write will require an allocation
2291 * @ip: the file being written to
2292 * @offset: the offset to write to
2293 * @len: the number of bytes being written
2294 *
2295 * Returns: 1 if an alloc is required, 0 otherwise
2296 */
2297
2298int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
2299 unsigned int len)
2300{
2301 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
2302 struct buffer_head bh;
2303 unsigned int shift;
2304 u64 lblock, lblock_stop, size;
2305 u64 end_of_file;
2306
2307 if (!len)
2308 return 0;
2309
2310 if (gfs2_is_stuffed(ip)) {
2311 if (offset + len > gfs2_max_stuffed_size(ip))
2312 return 1;
2313 return 0;
2314 }
2315
2316 shift = sdp->sd_sb.sb_bsize_shift;
2317 BUG_ON(gfs2_is_dir(ip));
2318 end_of_file = (i_size_read(&ip->i_inode) + sdp->sd_sb.sb_bsize - 1) >> shift;
2319 lblock = offset >> shift;
2320 lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
2321 if (lblock_stop > end_of_file && ip != GFS2_I(sdp->sd_rindex))
2322 return 1;
2323
2324 size = (lblock_stop - lblock) << shift;
2325 do {
2326 bh.b_state = 0;
2327 bh.b_size = size;
2328 gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
2329 if (!buffer_mapped(&bh))
2330 return 1;
2331 size -= bh.b_size;
2332 lblock += (bh.b_size >> ip->i_inode.i_blkbits);
2333 } while(size > 0);
2334
2335 return 0;
2336}
2337
2338static int stuffed_zero_range(struct inode *inode, loff_t offset, loff_t length)
2339{
2340 struct gfs2_inode *ip = GFS2_I(inode);
2341 struct buffer_head *dibh;
2342 int error;
2343
2344 if (offset >= inode->i_size)
2345 return 0;
2346 if (offset + length > inode->i_size)
2347 length = inode->i_size - offset;
2348
2349 error = gfs2_meta_inode_buffer(ip, &dibh);
2350 if (error)
2351 return error;
2352 gfs2_trans_add_meta(ip->i_gl, dibh);
2353 memset(dibh->b_data + sizeof(struct gfs2_dinode) + offset, 0,
2354 length);
2355 brelse(dibh);
2356 return 0;
2357}
2358
2359static int gfs2_journaled_truncate_range(struct inode *inode, loff_t offset,
2360 loff_t length)
2361{
2362 struct gfs2_sbd *sdp = GFS2_SB(inode);
2363 loff_t max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
2364 int error;
2365
2366 while (length) {
2367 struct gfs2_trans *tr;
2368 loff_t chunk;
2369 unsigned int offs;
2370
2371 chunk = length;
2372 if (chunk > max_chunk)
2373 chunk = max_chunk;
2374
2375 offs = offset & ~PAGE_MASK;
2376 if (offs && chunk > PAGE_SIZE)
2377 chunk = offs + ((chunk - offs) & PAGE_MASK);
2378
2379 truncate_pagecache_range(inode, offset, chunk);
2380 offset += chunk;
2381 length -= chunk;
2382
2383 tr = current->journal_info;
2384 if (!test_bit(TR_TOUCHED, &tr->tr_flags))
2385 continue;
2386
2387 gfs2_trans_end(sdp);
2388 error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
2389 if (error)
2390 return error;
2391 }
2392 return 0;
2393}
2394
2395int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length)
2396{
2397 struct inode *inode = file_inode(file);
2398 struct gfs2_inode *ip = GFS2_I(inode);
2399 struct gfs2_sbd *sdp = GFS2_SB(inode);
2400 unsigned int blocksize = i_blocksize(inode);
2401 loff_t start, end;
2402 int error;
2403
2404 if (!gfs2_is_stuffed(ip)) {
2405 unsigned int start_off, end_len;
2406
2407 start_off = offset & (blocksize - 1);
2408 end_len = (offset + length) & (blocksize - 1);
2409 if (start_off) {
2410 unsigned int len = length;
2411 if (length > blocksize - start_off)
2412 len = blocksize - start_off;
2413 error = gfs2_block_zero_range(inode, offset, len);
2414 if (error)
2415 goto out;
2416 if (start_off + length < blocksize)
2417 end_len = 0;
2418 }
2419 if (end_len) {
2420 error = gfs2_block_zero_range(inode,
2421 offset + length - end_len, end_len);
2422 if (error)
2423 goto out;
2424 }
2425 }
2426
2427 start = round_down(offset, blocksize);
2428 end = round_up(offset + length, blocksize) - 1;
2429 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
2430 if (error)
2431 return error;
2432
2433 if (gfs2_is_jdata(ip))
2434 error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA,
2435 GFS2_JTRUNC_REVOKES);
2436 else
2437 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
2438 if (error)
2439 return error;
2440
2441 if (gfs2_is_stuffed(ip)) {
2442 error = stuffed_zero_range(inode, offset, length);
2443 if (error)
2444 goto out;
2445 }
2446
2447 if (gfs2_is_jdata(ip)) {
2448 BUG_ON(!current->journal_info);
2449 gfs2_journaled_truncate_range(inode, offset, length);
2450 } else
2451 truncate_pagecache_range(inode, offset, offset + length - 1);
2452
2453 file_update_time(file);
2454 mark_inode_dirty(inode);
2455
2456 if (current->journal_info)
2457 gfs2_trans_end(sdp);
2458
2459 if (!gfs2_is_stuffed(ip))
2460 error = punch_hole(ip, offset, length);
2461
2462out:
2463 if (current->journal_info)
2464 gfs2_trans_end(sdp);
2465 return error;
2466}
2467
2468static int gfs2_map_blocks(struct iomap_writepage_ctx *wpc, struct inode *inode,
2469 loff_t offset, unsigned int len)
2470{
2471 int ret;
2472
2473 if (WARN_ON_ONCE(gfs2_is_stuffed(GFS2_I(inode))))
2474 return -EIO;
2475
2476 if (offset >= wpc->iomap.offset &&
2477 offset < wpc->iomap.offset + wpc->iomap.length)
2478 return 0;
2479
2480 memset(&wpc->iomap, 0, sizeof(wpc->iomap));
2481 ret = gfs2_iomap_get(inode, offset, INT_MAX, &wpc->iomap);
2482 return ret;
2483}
2484
2485const struct iomap_writeback_ops gfs2_writeback_ops = {
2486 .map_blocks = gfs2_map_blocks,
2487};