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v4.6
 
  1/*
  2 *  linux/fs/hfsplus/extents.c
  3 *
  4 * Copyright (C) 2001
  5 * Brad Boyer (flar@allandria.com)
  6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
  7 *
  8 * Handling of Extents both in catalog and extents overflow trees
  9 */
 10
 11#include <linux/errno.h>
 12#include <linux/fs.h>
 13#include <linux/pagemap.h>
 14
 15#include "hfsplus_fs.h"
 16#include "hfsplus_raw.h"
 17
 18/* Compare two extents keys, returns 0 on same, pos/neg for difference */
 19int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
 20			const hfsplus_btree_key *k2)
 21{
 22	__be32 k1id, k2id;
 23	__be32 k1s, k2s;
 24
 25	k1id = k1->ext.cnid;
 26	k2id = k2->ext.cnid;
 27	if (k1id != k2id)
 28		return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
 29
 30	if (k1->ext.fork_type != k2->ext.fork_type)
 31		return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
 32
 33	k1s = k1->ext.start_block;
 34	k2s = k2->ext.start_block;
 35	if (k1s == k2s)
 36		return 0;
 37	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
 38}
 39
 40static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
 41				  u32 block, u8 type)
 42{
 43	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
 44	key->ext.cnid = cpu_to_be32(cnid);
 45	key->ext.start_block = cpu_to_be32(block);
 46	key->ext.fork_type = type;
 47	key->ext.pad = 0;
 48}
 49
 50static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
 51{
 52	int i;
 53	u32 count;
 54
 55	for (i = 0; i < 8; ext++, i++) {
 56		count = be32_to_cpu(ext->block_count);
 57		if (off < count)
 58			return be32_to_cpu(ext->start_block) + off;
 59		off -= count;
 60	}
 61	/* panic? */
 62	return 0;
 63}
 64
 65static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
 66{
 67	int i;
 68	u32 count = 0;
 69
 70	for (i = 0; i < 8; ext++, i++)
 71		count += be32_to_cpu(ext->block_count);
 72	return count;
 73}
 74
 75static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
 76{
 77	int i;
 78
 79	ext += 7;
 80	for (i = 0; i < 7; ext--, i++)
 81		if (ext->block_count)
 82			break;
 83	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
 84}
 85
 86static int __hfsplus_ext_write_extent(struct inode *inode,
 87		struct hfs_find_data *fd)
 88{
 89	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 90	int res;
 91
 92	WARN_ON(!mutex_is_locked(&hip->extents_lock));
 93
 94	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
 95			      HFSPLUS_IS_RSRC(inode) ?
 96				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
 97
 98	res = hfs_brec_find(fd, hfs_find_rec_by_key);
 99	if (hip->extent_state & HFSPLUS_EXT_NEW) {
100		if (res != -ENOENT)
101			return res;
 
 
 
 
102		hfs_brec_insert(fd, hip->cached_extents,
103				sizeof(hfsplus_extent_rec));
104		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
105	} else {
106		if (res)
107			return res;
108		hfs_bnode_write(fd->bnode, hip->cached_extents,
109				fd->entryoffset, fd->entrylength);
110		hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
111	}
112
113	/*
114	 * We can't just use hfsplus_mark_inode_dirty here, because we
115	 * also get called from hfsplus_write_inode, which should not
116	 * redirty the inode.  Instead the callers have to be careful
117	 * to explicily mark the inode dirty, too.
118	 */
119	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
120
121	return 0;
122}
123
124static int hfsplus_ext_write_extent_locked(struct inode *inode)
125{
126	int res = 0;
127
128	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
129		struct hfs_find_data fd;
130
131		res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
132		if (res)
133			return res;
134		res = __hfsplus_ext_write_extent(inode, &fd);
135		hfs_find_exit(&fd);
136	}
137	return res;
138}
139
140int hfsplus_ext_write_extent(struct inode *inode)
141{
142	int res;
143
144	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
145	res = hfsplus_ext_write_extent_locked(inode);
146	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
147
148	return res;
149}
150
151static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
152					    struct hfsplus_extent *extent,
153					    u32 cnid, u32 block, u8 type)
154{
155	int res;
156
157	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
158	fd->key->ext.cnid = 0;
159	res = hfs_brec_find(fd, hfs_find_rec_by_key);
160	if (res && res != -ENOENT)
161		return res;
162	if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
163	    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
164		return -ENOENT;
165	if (fd->entrylength != sizeof(hfsplus_extent_rec))
166		return -EIO;
167	hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
168		sizeof(hfsplus_extent_rec));
169	return 0;
170}
171
172static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
173		struct inode *inode, u32 block)
174{
175	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
176	int res;
177
178	WARN_ON(!mutex_is_locked(&hip->extents_lock));
179
180	if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
181		res = __hfsplus_ext_write_extent(inode, fd);
182		if (res)
183			return res;
184	}
185
186	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
187					block, HFSPLUS_IS_RSRC(inode) ?
188						HFSPLUS_TYPE_RSRC :
189						HFSPLUS_TYPE_DATA);
190	if (!res) {
191		hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
192		hip->cached_blocks =
193			hfsplus_ext_block_count(hip->cached_extents);
194	} else {
195		hip->cached_start = hip->cached_blocks = 0;
196		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
197	}
198	return res;
199}
200
201static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
202{
203	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
204	struct hfs_find_data fd;
205	int res;
206
207	if (block >= hip->cached_start &&
208	    block < hip->cached_start + hip->cached_blocks)
209		return 0;
210
211	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
212	if (!res) {
213		res = __hfsplus_ext_cache_extent(&fd, inode, block);
214		hfs_find_exit(&fd);
215	}
216	return res;
217}
218
219/* Get a block at iblock for inode, possibly allocating if create */
220int hfsplus_get_block(struct inode *inode, sector_t iblock,
221		      struct buffer_head *bh_result, int create)
222{
223	struct super_block *sb = inode->i_sb;
224	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
225	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
226	int res = -EIO;
227	u32 ablock, dblock, mask;
228	sector_t sector;
229	int was_dirty = 0;
230
231	/* Convert inode block to disk allocation block */
232	ablock = iblock >> sbi->fs_shift;
233
234	if (iblock >= hip->fs_blocks) {
235		if (iblock > hip->fs_blocks || !create)
 
 
236			return -EIO;
237		if (ablock >= hip->alloc_blocks) {
238			res = hfsplus_file_extend(inode, false);
239			if (res)
240				return res;
241		}
242	} else
243		create = 0;
244
245	if (ablock < hip->first_blocks) {
246		dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
247		goto done;
248	}
249
250	if (inode->i_ino == HFSPLUS_EXT_CNID)
251		return -EIO;
252
253	mutex_lock(&hip->extents_lock);
254
255	/*
256	 * hfsplus_ext_read_extent will write out a cached extent into
257	 * the extents btree.  In that case we may have to mark the inode
258	 * dirty even for a pure read of an extent here.
259	 */
260	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
261	res = hfsplus_ext_read_extent(inode, ablock);
262	if (res) {
263		mutex_unlock(&hip->extents_lock);
264		return -EIO;
265	}
266	dblock = hfsplus_ext_find_block(hip->cached_extents,
267					ablock - hip->cached_start);
268	mutex_unlock(&hip->extents_lock);
269
270done:
271	hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
272		inode->i_ino, (long long)iblock, dblock);
273
274	mask = (1 << sbi->fs_shift) - 1;
275	sector = ((sector_t)dblock << sbi->fs_shift) +
276		  sbi->blockoffset + (iblock & mask);
277	map_bh(bh_result, sb, sector);
278
279	if (create) {
280		set_buffer_new(bh_result);
281		hip->phys_size += sb->s_blocksize;
282		hip->fs_blocks++;
283		inode_add_bytes(inode, sb->s_blocksize);
284	}
285	if (create || was_dirty)
286		mark_inode_dirty(inode);
287	return 0;
288}
289
290static void hfsplus_dump_extent(struct hfsplus_extent *extent)
291{
292	int i;
293
294	hfs_dbg(EXTENT, "   ");
295	for (i = 0; i < 8; i++)
296		hfs_dbg_cont(EXTENT, " %u:%u",
297			     be32_to_cpu(extent[i].start_block),
298			     be32_to_cpu(extent[i].block_count));
299	hfs_dbg_cont(EXTENT, "\n");
300}
301
302static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
303			      u32 alloc_block, u32 block_count)
304{
305	u32 count, start;
306	int i;
307
308	hfsplus_dump_extent(extent);
309	for (i = 0; i < 8; extent++, i++) {
310		count = be32_to_cpu(extent->block_count);
311		if (offset == count) {
312			start = be32_to_cpu(extent->start_block);
313			if (alloc_block != start + count) {
314				if (++i >= 8)
315					return -ENOSPC;
316				extent++;
317				extent->start_block = cpu_to_be32(alloc_block);
318			} else
319				block_count += count;
320			extent->block_count = cpu_to_be32(block_count);
321			return 0;
322		} else if (offset < count)
323			break;
324		offset -= count;
325	}
326	/* panic? */
327	return -EIO;
328}
329
330static int hfsplus_free_extents(struct super_block *sb,
331				struct hfsplus_extent *extent,
332				u32 offset, u32 block_nr)
333{
334	u32 count, start;
335	int i;
336	int err = 0;
337
 
 
 
338	hfsplus_dump_extent(extent);
339	for (i = 0; i < 8; extent++, i++) {
340		count = be32_to_cpu(extent->block_count);
341		if (offset == count)
342			goto found;
343		else if (offset < count)
344			break;
345		offset -= count;
346	}
347	/* panic? */
348	return -EIO;
349found:
350	for (;;) {
351		start = be32_to_cpu(extent->start_block);
352		if (count <= block_nr) {
353			err = hfsplus_block_free(sb, start, count);
354			if (err) {
355				pr_err("can't free extent\n");
356				hfs_dbg(EXTENT, " start: %u count: %u\n",
357					start, count);
358			}
359			extent->block_count = 0;
360			extent->start_block = 0;
361			block_nr -= count;
362		} else {
363			count -= block_nr;
364			err = hfsplus_block_free(sb, start + count, block_nr);
365			if (err) {
366				pr_err("can't free extent\n");
367				hfs_dbg(EXTENT, " start: %u count: %u\n",
368					start, count);
369			}
370			extent->block_count = cpu_to_be32(count);
371			block_nr = 0;
372		}
373		if (!block_nr || !i) {
374			/*
375			 * Try to free all extents and
376			 * return only last error
377			 */
378			return err;
379		}
380		i--;
381		extent--;
382		count = be32_to_cpu(extent->block_count);
383	}
384}
385
386int hfsplus_free_fork(struct super_block *sb, u32 cnid,
387		struct hfsplus_fork_raw *fork, int type)
388{
389	struct hfs_find_data fd;
390	hfsplus_extent_rec ext_entry;
391	u32 total_blocks, blocks, start;
392	int res, i;
393
394	total_blocks = be32_to_cpu(fork->total_blocks);
395	if (!total_blocks)
396		return 0;
397
398	blocks = 0;
399	for (i = 0; i < 8; i++)
400		blocks += be32_to_cpu(fork->extents[i].block_count);
401
402	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
403	if (res)
404		return res;
405	if (total_blocks == blocks)
406		return 0;
407
408	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
409	if (res)
410		return res;
411	do {
412		res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
413						total_blocks, type);
414		if (res)
415			break;
416		start = be32_to_cpu(fd.key->ext.start_block);
417		hfsplus_free_extents(sb, ext_entry,
418				     total_blocks - start,
419				     total_blocks);
420		hfs_brec_remove(&fd);
 
 
 
 
421		total_blocks = start;
 
 
422	} while (total_blocks > blocks);
423	hfs_find_exit(&fd);
424
425	return res;
426}
427
428int hfsplus_file_extend(struct inode *inode, bool zeroout)
429{
430	struct super_block *sb = inode->i_sb;
431	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
432	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
433	u32 start, len, goal;
434	int res;
435
436	if (sbi->alloc_file->i_size * 8 <
437	    sbi->total_blocks - sbi->free_blocks + 8) {
438		/* extend alloc file */
439		pr_err("extend alloc file! (%llu,%u,%u)\n",
440		       sbi->alloc_file->i_size * 8,
441		       sbi->total_blocks, sbi->free_blocks);
442		return -ENOSPC;
443	}
444
445	mutex_lock(&hip->extents_lock);
446	if (hip->alloc_blocks == hip->first_blocks)
447		goal = hfsplus_ext_lastblock(hip->first_extents);
448	else {
449		res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
450		if (res)
451			goto out;
452		goal = hfsplus_ext_lastblock(hip->cached_extents);
453	}
454
455	len = hip->clump_blocks;
456	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
457	if (start >= sbi->total_blocks) {
458		start = hfsplus_block_allocate(sb, goal, 0, &len);
459		if (start >= goal) {
460			res = -ENOSPC;
461			goto out;
462		}
463	}
464
465	if (zeroout) {
466		res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
467		if (res)
468			goto out;
469	}
470
471	hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
472
473	if (hip->alloc_blocks <= hip->first_blocks) {
474		if (!hip->first_blocks) {
475			hfs_dbg(EXTENT, "first extents\n");
476			/* no extents yet */
477			hip->first_extents[0].start_block = cpu_to_be32(start);
478			hip->first_extents[0].block_count = cpu_to_be32(len);
479			res = 0;
480		} else {
481			/* try to append to extents in inode */
482			res = hfsplus_add_extent(hip->first_extents,
483						 hip->alloc_blocks,
484						 start, len);
485			if (res == -ENOSPC)
486				goto insert_extent;
487		}
488		if (!res) {
489			hfsplus_dump_extent(hip->first_extents);
490			hip->first_blocks += len;
491		}
492	} else {
493		res = hfsplus_add_extent(hip->cached_extents,
494					 hip->alloc_blocks - hip->cached_start,
495					 start, len);
496		if (!res) {
497			hfsplus_dump_extent(hip->cached_extents);
498			hip->extent_state |= HFSPLUS_EXT_DIRTY;
499			hip->cached_blocks += len;
500		} else if (res == -ENOSPC)
501			goto insert_extent;
502	}
503out:
504	if (!res) {
505		hip->alloc_blocks += len;
506		mutex_unlock(&hip->extents_lock);
507		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
508		return 0;
509	}
510	mutex_unlock(&hip->extents_lock);
511	return res;
512
513insert_extent:
514	hfs_dbg(EXTENT, "insert new extent\n");
515	res = hfsplus_ext_write_extent_locked(inode);
516	if (res)
517		goto out;
518
519	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
520	hip->cached_extents[0].start_block = cpu_to_be32(start);
521	hip->cached_extents[0].block_count = cpu_to_be32(len);
522	hfsplus_dump_extent(hip->cached_extents);
523	hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
524	hip->cached_start = hip->alloc_blocks;
525	hip->cached_blocks = len;
526
527	res = 0;
528	goto out;
529}
530
531void hfsplus_file_truncate(struct inode *inode)
532{
533	struct super_block *sb = inode->i_sb;
534	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
535	struct hfs_find_data fd;
536	u32 alloc_cnt, blk_cnt, start;
537	int res;
538
539	hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
540		inode->i_ino, (long long)hip->phys_size, inode->i_size);
541
542	if (inode->i_size > hip->phys_size) {
543		struct address_space *mapping = inode->i_mapping;
544		struct page *page;
545		void *fsdata;
546		loff_t size = inode->i_size;
547
548		res = pagecache_write_begin(NULL, mapping, size, 0,
549						AOP_FLAG_UNINTERRUPTIBLE,
550						&page, &fsdata);
551		if (res)
552			return;
553		res = pagecache_write_end(NULL, mapping, size,
554			0, 0, page, fsdata);
555		if (res < 0)
556			return;
557		mark_inode_dirty(inode);
558		return;
559	} else if (inode->i_size == hip->phys_size)
560		return;
561
562	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
563			HFSPLUS_SB(sb)->alloc_blksz_shift;
564
565	mutex_lock(&hip->extents_lock);
566
567	alloc_cnt = hip->alloc_blocks;
568	if (blk_cnt == alloc_cnt)
569		goto out_unlock;
570
571	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
572	if (res) {
573		mutex_unlock(&hip->extents_lock);
574		/* XXX: We lack error handling of hfsplus_file_truncate() */
575		return;
576	}
577	while (1) {
578		if (alloc_cnt == hip->first_blocks) {
 
579			hfsplus_free_extents(sb, hip->first_extents,
580					     alloc_cnt, alloc_cnt - blk_cnt);
581			hfsplus_dump_extent(hip->first_extents);
582			hip->first_blocks = blk_cnt;
 
 
583			break;
584		}
585		res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
586		if (res)
587			break;
 
588		start = hip->cached_start;
 
 
 
589		hfsplus_free_extents(sb, hip->cached_extents,
590				     alloc_cnt - start, alloc_cnt - blk_cnt);
591		hfsplus_dump_extent(hip->cached_extents);
 
 
592		if (blk_cnt > start) {
593			hip->extent_state |= HFSPLUS_EXT_DIRTY;
594			break;
595		}
596		alloc_cnt = start;
597		hip->cached_start = hip->cached_blocks = 0;
598		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
599		hfs_brec_remove(&fd);
600	}
601	hfs_find_exit(&fd);
602
603	hip->alloc_blocks = blk_cnt;
604out_unlock:
605	mutex_unlock(&hip->extents_lock);
606	hip->phys_size = inode->i_size;
607	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
608		sb->s_blocksize_bits;
609	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
610	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
611}
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/hfsplus/extents.c
  4 *
  5 * Copyright (C) 2001
  6 * Brad Boyer (flar@allandria.com)
  7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
  8 *
  9 * Handling of Extents both in catalog and extents overflow trees
 10 */
 11
 12#include <linux/errno.h>
 13#include <linux/fs.h>
 14#include <linux/pagemap.h>
 15
 16#include "hfsplus_fs.h"
 17#include "hfsplus_raw.h"
 18
 19/* Compare two extents keys, returns 0 on same, pos/neg for difference */
 20int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
 21			const hfsplus_btree_key *k2)
 22{
 23	__be32 k1id, k2id;
 24	__be32 k1s, k2s;
 25
 26	k1id = k1->ext.cnid;
 27	k2id = k2->ext.cnid;
 28	if (k1id != k2id)
 29		return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
 30
 31	if (k1->ext.fork_type != k2->ext.fork_type)
 32		return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
 33
 34	k1s = k1->ext.start_block;
 35	k2s = k2->ext.start_block;
 36	if (k1s == k2s)
 37		return 0;
 38	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
 39}
 40
 41static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
 42				  u32 block, u8 type)
 43{
 44	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
 45	key->ext.cnid = cpu_to_be32(cnid);
 46	key->ext.start_block = cpu_to_be32(block);
 47	key->ext.fork_type = type;
 48	key->ext.pad = 0;
 49}
 50
 51static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
 52{
 53	int i;
 54	u32 count;
 55
 56	for (i = 0; i < 8; ext++, i++) {
 57		count = be32_to_cpu(ext->block_count);
 58		if (off < count)
 59			return be32_to_cpu(ext->start_block) + off;
 60		off -= count;
 61	}
 62	/* panic? */
 63	return 0;
 64}
 65
 66static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
 67{
 68	int i;
 69	u32 count = 0;
 70
 71	for (i = 0; i < 8; ext++, i++)
 72		count += be32_to_cpu(ext->block_count);
 73	return count;
 74}
 75
 76static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
 77{
 78	int i;
 79
 80	ext += 7;
 81	for (i = 0; i < 7; ext--, i++)
 82		if (ext->block_count)
 83			break;
 84	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
 85}
 86
 87static int __hfsplus_ext_write_extent(struct inode *inode,
 88		struct hfs_find_data *fd)
 89{
 90	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
 91	int res;
 92
 93	WARN_ON(!mutex_is_locked(&hip->extents_lock));
 94
 95	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
 96			      HFSPLUS_IS_RSRC(inode) ?
 97				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
 98
 99	res = hfs_brec_find(fd, hfs_find_rec_by_key);
100	if (hip->extent_state & HFSPLUS_EXT_NEW) {
101		if (res != -ENOENT)
102			return res;
103		/* Fail early and avoid ENOSPC during the btree operation */
104		res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
105		if (res)
106			return res;
107		hfs_brec_insert(fd, hip->cached_extents,
108				sizeof(hfsplus_extent_rec));
109		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
110	} else {
111		if (res)
112			return res;
113		hfs_bnode_write(fd->bnode, hip->cached_extents,
114				fd->entryoffset, fd->entrylength);
115		hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
116	}
117
118	/*
119	 * We can't just use hfsplus_mark_inode_dirty here, because we
120	 * also get called from hfsplus_write_inode, which should not
121	 * redirty the inode.  Instead the callers have to be careful
122	 * to explicily mark the inode dirty, too.
123	 */
124	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
125
126	return 0;
127}
128
129static int hfsplus_ext_write_extent_locked(struct inode *inode)
130{
131	int res = 0;
132
133	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
134		struct hfs_find_data fd;
135
136		res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
137		if (res)
138			return res;
139		res = __hfsplus_ext_write_extent(inode, &fd);
140		hfs_find_exit(&fd);
141	}
142	return res;
143}
144
145int hfsplus_ext_write_extent(struct inode *inode)
146{
147	int res;
148
149	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
150	res = hfsplus_ext_write_extent_locked(inode);
151	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
152
153	return res;
154}
155
156static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
157					    struct hfsplus_extent *extent,
158					    u32 cnid, u32 block, u8 type)
159{
160	int res;
161
162	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
163	fd->key->ext.cnid = 0;
164	res = hfs_brec_find(fd, hfs_find_rec_by_key);
165	if (res && res != -ENOENT)
166		return res;
167	if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
168	    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
169		return -ENOENT;
170	if (fd->entrylength != sizeof(hfsplus_extent_rec))
171		return -EIO;
172	hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
173		sizeof(hfsplus_extent_rec));
174	return 0;
175}
176
177static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
178		struct inode *inode, u32 block)
179{
180	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
181	int res;
182
183	WARN_ON(!mutex_is_locked(&hip->extents_lock));
184
185	if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
186		res = __hfsplus_ext_write_extent(inode, fd);
187		if (res)
188			return res;
189	}
190
191	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
192					block, HFSPLUS_IS_RSRC(inode) ?
193						HFSPLUS_TYPE_RSRC :
194						HFSPLUS_TYPE_DATA);
195	if (!res) {
196		hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
197		hip->cached_blocks =
198			hfsplus_ext_block_count(hip->cached_extents);
199	} else {
200		hip->cached_start = hip->cached_blocks = 0;
201		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
202	}
203	return res;
204}
205
206static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
207{
208	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
209	struct hfs_find_data fd;
210	int res;
211
212	if (block >= hip->cached_start &&
213	    block < hip->cached_start + hip->cached_blocks)
214		return 0;
215
216	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
217	if (!res) {
218		res = __hfsplus_ext_cache_extent(&fd, inode, block);
219		hfs_find_exit(&fd);
220	}
221	return res;
222}
223
224/* Get a block at iblock for inode, possibly allocating if create */
225int hfsplus_get_block(struct inode *inode, sector_t iblock,
226		      struct buffer_head *bh_result, int create)
227{
228	struct super_block *sb = inode->i_sb;
229	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
230	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
231	int res = -EIO;
232	u32 ablock, dblock, mask;
233	sector_t sector;
234	int was_dirty = 0;
235
236	/* Convert inode block to disk allocation block */
237	ablock = iblock >> sbi->fs_shift;
238
239	if (iblock >= hip->fs_blocks) {
240		if (!create)
241			return 0;
242		if (iblock > hip->fs_blocks)
243			return -EIO;
244		if (ablock >= hip->alloc_blocks) {
245			res = hfsplus_file_extend(inode, false);
246			if (res)
247				return res;
248		}
249	} else
250		create = 0;
251
252	if (ablock < hip->first_blocks) {
253		dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
254		goto done;
255	}
256
257	if (inode->i_ino == HFSPLUS_EXT_CNID)
258		return -EIO;
259
260	mutex_lock(&hip->extents_lock);
261
262	/*
263	 * hfsplus_ext_read_extent will write out a cached extent into
264	 * the extents btree.  In that case we may have to mark the inode
265	 * dirty even for a pure read of an extent here.
266	 */
267	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
268	res = hfsplus_ext_read_extent(inode, ablock);
269	if (res) {
270		mutex_unlock(&hip->extents_lock);
271		return -EIO;
272	}
273	dblock = hfsplus_ext_find_block(hip->cached_extents,
274					ablock - hip->cached_start);
275	mutex_unlock(&hip->extents_lock);
276
277done:
278	hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
279		inode->i_ino, (long long)iblock, dblock);
280
281	mask = (1 << sbi->fs_shift) - 1;
282	sector = ((sector_t)dblock << sbi->fs_shift) +
283		  sbi->blockoffset + (iblock & mask);
284	map_bh(bh_result, sb, sector);
285
286	if (create) {
287		set_buffer_new(bh_result);
288		hip->phys_size += sb->s_blocksize;
289		hip->fs_blocks++;
290		inode_add_bytes(inode, sb->s_blocksize);
291	}
292	if (create || was_dirty)
293		mark_inode_dirty(inode);
294	return 0;
295}
296
297static void hfsplus_dump_extent(struct hfsplus_extent *extent)
298{
299	int i;
300
301	hfs_dbg(EXTENT, "   ");
302	for (i = 0; i < 8; i++)
303		hfs_dbg_cont(EXTENT, " %u:%u",
304			     be32_to_cpu(extent[i].start_block),
305			     be32_to_cpu(extent[i].block_count));
306	hfs_dbg_cont(EXTENT, "\n");
307}
308
309static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
310			      u32 alloc_block, u32 block_count)
311{
312	u32 count, start;
313	int i;
314
315	hfsplus_dump_extent(extent);
316	for (i = 0; i < 8; extent++, i++) {
317		count = be32_to_cpu(extent->block_count);
318		if (offset == count) {
319			start = be32_to_cpu(extent->start_block);
320			if (alloc_block != start + count) {
321				if (++i >= 8)
322					return -ENOSPC;
323				extent++;
324				extent->start_block = cpu_to_be32(alloc_block);
325			} else
326				block_count += count;
327			extent->block_count = cpu_to_be32(block_count);
328			return 0;
329		} else if (offset < count)
330			break;
331		offset -= count;
332	}
333	/* panic? */
334	return -EIO;
335}
336
337static int hfsplus_free_extents(struct super_block *sb,
338				struct hfsplus_extent *extent,
339				u32 offset, u32 block_nr)
340{
341	u32 count, start;
342	int i;
343	int err = 0;
344
345	/* Mapping the allocation file may lock the extent tree */
346	WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock));
347
348	hfsplus_dump_extent(extent);
349	for (i = 0; i < 8; extent++, i++) {
350		count = be32_to_cpu(extent->block_count);
351		if (offset == count)
352			goto found;
353		else if (offset < count)
354			break;
355		offset -= count;
356	}
357	/* panic? */
358	return -EIO;
359found:
360	for (;;) {
361		start = be32_to_cpu(extent->start_block);
362		if (count <= block_nr) {
363			err = hfsplus_block_free(sb, start, count);
364			if (err) {
365				pr_err("can't free extent\n");
366				hfs_dbg(EXTENT, " start: %u count: %u\n",
367					start, count);
368			}
369			extent->block_count = 0;
370			extent->start_block = 0;
371			block_nr -= count;
372		} else {
373			count -= block_nr;
374			err = hfsplus_block_free(sb, start + count, block_nr);
375			if (err) {
376				pr_err("can't free extent\n");
377				hfs_dbg(EXTENT, " start: %u count: %u\n",
378					start, count);
379			}
380			extent->block_count = cpu_to_be32(count);
381			block_nr = 0;
382		}
383		if (!block_nr || !i) {
384			/*
385			 * Try to free all extents and
386			 * return only last error
387			 */
388			return err;
389		}
390		i--;
391		extent--;
392		count = be32_to_cpu(extent->block_count);
393	}
394}
395
396int hfsplus_free_fork(struct super_block *sb, u32 cnid,
397		struct hfsplus_fork_raw *fork, int type)
398{
399	struct hfs_find_data fd;
400	hfsplus_extent_rec ext_entry;
401	u32 total_blocks, blocks, start;
402	int res, i;
403
404	total_blocks = be32_to_cpu(fork->total_blocks);
405	if (!total_blocks)
406		return 0;
407
408	blocks = 0;
409	for (i = 0; i < 8; i++)
410		blocks += be32_to_cpu(fork->extents[i].block_count);
411
412	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
413	if (res)
414		return res;
415	if (total_blocks == blocks)
416		return 0;
417
418	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
419	if (res)
420		return res;
421	do {
422		res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
423						total_blocks, type);
424		if (res)
425			break;
426		start = be32_to_cpu(fd.key->ext.start_block);
 
 
 
427		hfs_brec_remove(&fd);
428
429		mutex_unlock(&fd.tree->tree_lock);
430		hfsplus_free_extents(sb, ext_entry, total_blocks - start,
431				     total_blocks);
432		total_blocks = start;
433		mutex_lock_nested(&fd.tree->tree_lock,
434			hfsplus_btree_lock_class(fd.tree));
435	} while (total_blocks > blocks);
436	hfs_find_exit(&fd);
437
438	return res;
439}
440
441int hfsplus_file_extend(struct inode *inode, bool zeroout)
442{
443	struct super_block *sb = inode->i_sb;
444	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
445	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
446	u32 start, len, goal;
447	int res;
448
449	if (sbi->alloc_file->i_size * 8 <
450	    sbi->total_blocks - sbi->free_blocks + 8) {
451		/* extend alloc file */
452		pr_err_ratelimited("extend alloc file! (%llu,%u,%u)\n",
453				   sbi->alloc_file->i_size * 8,
454				   sbi->total_blocks, sbi->free_blocks);
455		return -ENOSPC;
456	}
457
458	mutex_lock(&hip->extents_lock);
459	if (hip->alloc_blocks == hip->first_blocks)
460		goal = hfsplus_ext_lastblock(hip->first_extents);
461	else {
462		res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
463		if (res)
464			goto out;
465		goal = hfsplus_ext_lastblock(hip->cached_extents);
466	}
467
468	len = hip->clump_blocks;
469	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
470	if (start >= sbi->total_blocks) {
471		start = hfsplus_block_allocate(sb, goal, 0, &len);
472		if (start >= goal) {
473			res = -ENOSPC;
474			goto out;
475		}
476	}
477
478	if (zeroout) {
479		res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
480		if (res)
481			goto out;
482	}
483
484	hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
485
486	if (hip->alloc_blocks <= hip->first_blocks) {
487		if (!hip->first_blocks) {
488			hfs_dbg(EXTENT, "first extents\n");
489			/* no extents yet */
490			hip->first_extents[0].start_block = cpu_to_be32(start);
491			hip->first_extents[0].block_count = cpu_to_be32(len);
492			res = 0;
493		} else {
494			/* try to append to extents in inode */
495			res = hfsplus_add_extent(hip->first_extents,
496						 hip->alloc_blocks,
497						 start, len);
498			if (res == -ENOSPC)
499				goto insert_extent;
500		}
501		if (!res) {
502			hfsplus_dump_extent(hip->first_extents);
503			hip->first_blocks += len;
504		}
505	} else {
506		res = hfsplus_add_extent(hip->cached_extents,
507					 hip->alloc_blocks - hip->cached_start,
508					 start, len);
509		if (!res) {
510			hfsplus_dump_extent(hip->cached_extents);
511			hip->extent_state |= HFSPLUS_EXT_DIRTY;
512			hip->cached_blocks += len;
513		} else if (res == -ENOSPC)
514			goto insert_extent;
515	}
516out:
517	if (!res) {
518		hip->alloc_blocks += len;
519		mutex_unlock(&hip->extents_lock);
520		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
521		return 0;
522	}
523	mutex_unlock(&hip->extents_lock);
524	return res;
525
526insert_extent:
527	hfs_dbg(EXTENT, "insert new extent\n");
528	res = hfsplus_ext_write_extent_locked(inode);
529	if (res)
530		goto out;
531
532	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
533	hip->cached_extents[0].start_block = cpu_to_be32(start);
534	hip->cached_extents[0].block_count = cpu_to_be32(len);
535	hfsplus_dump_extent(hip->cached_extents);
536	hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
537	hip->cached_start = hip->alloc_blocks;
538	hip->cached_blocks = len;
539
540	res = 0;
541	goto out;
542}
543
544void hfsplus_file_truncate(struct inode *inode)
545{
546	struct super_block *sb = inode->i_sb;
547	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
548	struct hfs_find_data fd;
549	u32 alloc_cnt, blk_cnt, start;
550	int res;
551
552	hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
553		inode->i_ino, (long long)hip->phys_size, inode->i_size);
554
555	if (inode->i_size > hip->phys_size) {
556		struct address_space *mapping = inode->i_mapping;
557		struct folio *folio;
558		void *fsdata = NULL;
559		loff_t size = inode->i_size;
560
561		res = hfsplus_write_begin(NULL, mapping, size, 0,
562					  &folio, &fsdata);
 
563		if (res)
564			return;
565		res = generic_write_end(NULL, mapping, size, 0, 0,
566					folio, fsdata);
567		if (res < 0)
568			return;
569		mark_inode_dirty(inode);
570		return;
571	} else if (inode->i_size == hip->phys_size)
572		return;
573
574	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
575			HFSPLUS_SB(sb)->alloc_blksz_shift;
576
577	mutex_lock(&hip->extents_lock);
578
579	alloc_cnt = hip->alloc_blocks;
580	if (blk_cnt == alloc_cnt)
581		goto out_unlock;
582
583	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
584	if (res) {
585		mutex_unlock(&hip->extents_lock);
586		/* XXX: We lack error handling of hfsplus_file_truncate() */
587		return;
588	}
589	while (1) {
590		if (alloc_cnt == hip->first_blocks) {
591			mutex_unlock(&fd.tree->tree_lock);
592			hfsplus_free_extents(sb, hip->first_extents,
593					     alloc_cnt, alloc_cnt - blk_cnt);
594			hfsplus_dump_extent(hip->first_extents);
595			hip->first_blocks = blk_cnt;
596			mutex_lock_nested(&fd.tree->tree_lock,
597				hfsplus_btree_lock_class(fd.tree));
598			break;
599		}
600		res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
601		if (res)
602			break;
603
604		start = hip->cached_start;
605		if (blk_cnt <= start)
606			hfs_brec_remove(&fd);
607		mutex_unlock(&fd.tree->tree_lock);
608		hfsplus_free_extents(sb, hip->cached_extents,
609				     alloc_cnt - start, alloc_cnt - blk_cnt);
610		hfsplus_dump_extent(hip->cached_extents);
611		mutex_lock_nested(&fd.tree->tree_lock,
612				hfsplus_btree_lock_class(fd.tree));
613		if (blk_cnt > start) {
614			hip->extent_state |= HFSPLUS_EXT_DIRTY;
615			break;
616		}
617		alloc_cnt = start;
618		hip->cached_start = hip->cached_blocks = 0;
619		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
 
620	}
621	hfs_find_exit(&fd);
622
623	hip->alloc_blocks = blk_cnt;
624out_unlock:
625	mutex_unlock(&hip->extents_lock);
626	hip->phys_size = inode->i_size;
627	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
628		sb->s_blocksize_bits;
629	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
630	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
631}