1/*
2 * blknum.c --- Functions to handle blk64_t and high/low 64-bit block
3 * number.
4 *
5 * Copyright IBM Corporation, 2007
6 * Author Jose R. Santos <jrs@us.ibm.com>
7 *
8 * %Begin-Header%
9 * This file may be redistributed under the terms of the GNU Public
10 * License.
11 * %End-Header%
12 */
13
14#include "ext2fs.h"
15
16/*
17 * Return the group # of a block
18 */
19dgrp_t ext2fs_group_of_blk2(ext2_filsys fs, blk64_t blk)
20{
21	return (blk - fs->super->s_first_data_block) /
22		fs->super->s_blocks_per_group;
23}
24
25/*
26 * Return the first block (inclusive) in a group
27 */
28blk64_t ext2fs_group_first_block2(ext2_filsys fs, dgrp_t group)
29{
30	return fs->super->s_first_data_block +
31		((blk64_t)group * fs->super->s_blocks_per_group);
32}
33
34/*
35 * Return the last block (inclusive) in a group
36 */
37blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group)
38{
39	return (group == fs->group_desc_count - 1 ?
40		ext2fs_blocks_count(fs->super) - 1 :
41		ext2fs_group_first_block2(fs, group) +
42			(fs->super->s_blocks_per_group - 1));
43}
44
45/*
46 * Return the number of blocks in a group
47 */
48int ext2fs_group_blocks_count(ext2_filsys fs, dgrp_t group)
49{
50	int num_blocks;
51
52	if (group == fs->group_desc_count - 1) {
53		num_blocks = (ext2fs_blocks_count(fs->super) -
54				fs->super->s_first_data_block) %
55			      fs->super->s_blocks_per_group;
56		if (!num_blocks)
57			num_blocks = fs->super->s_blocks_per_group;
58	} else
59		num_blocks = fs->super->s_blocks_per_group;
60
61	return num_blocks;
62}
63
64/*
65 * Return the inode data block count
66 */
67blk64_t ext2fs_inode_data_blocks2(ext2_filsys fs,
68					struct ext2_inode *inode)
69{
70	return (inode->i_blocks |
71		((fs->super->s_feature_ro_compat &
72		  EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ?
73		 (__u64) inode->osd2.linux2.l_i_blocks_hi << 32 : 0)) -
74		(inode->i_file_acl ? fs->blocksize >> 9 : 0);
75}
76
77/*
78 * Return the inode i_blocks count
79 */
80blk64_t ext2fs_inode_i_blocks(ext2_filsys fs,
81					struct ext2_inode *inode)
82{
83	return (inode->i_blocks |
84		((fs->super->s_feature_ro_compat &
85		  EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ?
86		 (__u64)inode->osd2.linux2.l_i_blocks_hi << 32 : 0));
87}
88
89/*
90 * Return the fs block count
91 */
92blk64_t ext2fs_blocks_count(struct ext2_super_block *super)
93{
94	return super->s_blocks_count |
95		(super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
96		(__u64) super->s_blocks_count_hi << 32 : 0);
97}
98
99/*
100 * Set the fs block count
101 */
102void ext2fs_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
103{
104	super->s_blocks_count = blk;
105	if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
106		super->s_blocks_count_hi = (__u64) blk >> 32;
107}
108
109/*
110 * Add to the current fs block count
111 */
112void ext2fs_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
113{
114	blk64_t tmp;
115	tmp = ext2fs_blocks_count(super) + blk;
116	ext2fs_blocks_count_set(super, tmp);
117}
118
119/*
120 * Return the fs reserved block count
121 */
122blk64_t ext2fs_r_blocks_count(struct ext2_super_block *super)
123{
124	return super->s_r_blocks_count |
125		(super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
126		(__u64) super->s_r_blocks_count_hi << 32 : 0);
127}
128
129/*
130 * Set the fs reserved block count
131 */
132void ext2fs_r_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
133{
134	super->s_r_blocks_count = blk;
135	if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
136		super->s_r_blocks_count_hi = (__u64) blk >> 32;
137}
138
139/*
140 * Add to the current reserved fs block count
141 */
142void ext2fs_r_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
143{
144	blk64_t tmp;
145	tmp = ext2fs_r_blocks_count(super) + blk;
146	ext2fs_r_blocks_count_set(super, tmp);
147}
148
149/*
150 * Return the fs free block count
151 */
152blk64_t ext2fs_free_blocks_count(struct ext2_super_block *super)
153{
154	return super->s_free_blocks_count |
155		(super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
156		(__u64) super->s_free_blocks_hi << 32 : 0);
157}
158
159/*
160 * Set the fs free block count
161 */
162void ext2fs_free_blocks_count_set(struct ext2_super_block *super, blk64_t blk)
163{
164	super->s_free_blocks_count = blk;
165	if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
166		super->s_free_blocks_hi = (__u64) blk >> 32;
167}
168
169/*
170 * Add to the current free fs block count
171 */
172void ext2fs_free_blocks_count_add(struct ext2_super_block *super, blk64_t blk)
173{
174	blk64_t tmp;
175	tmp = ext2fs_free_blocks_count(super) + blk;
176	ext2fs_free_blocks_count_set(super, tmp);
177}
178
179/*
180 * Get a pointer to a block group descriptor.  We need the explicit
181 * pointer to the group desc for code that swaps block group
182 * descriptors before writing them out, as it wants to make a copy and
183 * do the swap there.
184 */
185struct ext2_group_desc *ext2fs_group_desc(ext2_filsys fs,
186					  struct opaque_ext2_group_desc *gdp,
187					  dgrp_t group)
188{
189	return (struct ext2_group_desc *)((char *)gdp +
190					  group * EXT2_DESC_SIZE(fs->super));
191}
192
193/* Do the same but as an ext4 group desc for internal use here */
194static struct ext4_group_desc *ext4fs_group_desc(ext2_filsys fs,
195					  struct opaque_ext2_group_desc *gdp,
196					  dgrp_t group)
197{
198	return (struct ext4_group_desc *)ext2fs_group_desc(fs, gdp, group);
199}
200
201/*
202 * Return the block bitmap block of a group
203 */
204blk64_t ext2fs_block_bitmap_loc(ext2_filsys fs, dgrp_t group)
205{
206	struct ext4_group_desc *gdp;
207
208	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
209	return gdp->bg_block_bitmap |
210		(fs->super->s_feature_incompat
211		 & EXT4_FEATURE_INCOMPAT_64BIT ?
212		 (__u64)gdp->bg_block_bitmap_hi << 32 : 0);
213}
214
215/*
216 * Set the block bitmap block of a group
217 */
218void ext2fs_block_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
219{
220	struct ext4_group_desc *gdp;
221
222	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
223	gdp->bg_block_bitmap = blk;
224	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
225		gdp->bg_block_bitmap_hi = (__u64) blk >> 32;
226}
227
228/*
229 * Return the inode bitmap block of a group
230 */
231blk64_t ext2fs_inode_bitmap_loc(ext2_filsys fs, dgrp_t group)
232{
233	struct ext4_group_desc *gdp;
234
235	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
236	return gdp->bg_inode_bitmap |
237		(fs->super->s_feature_incompat
238		 & EXT4_FEATURE_INCOMPAT_64BIT ?
239		 (__u64) gdp->bg_inode_bitmap_hi << 32 : 0);
240}
241
242/*
243 * Set the inode bitmap block of a group
244 */
245void ext2fs_inode_bitmap_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
246{
247	struct ext4_group_desc *gdp;
248
249	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
250	gdp->bg_inode_bitmap = blk;
251	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
252		gdp->bg_inode_bitmap_hi = (__u64) blk >> 32;
253}
254
255/*
256 * Return the inode table block of a group
257 */
258blk64_t ext2fs_inode_table_loc(ext2_filsys fs, dgrp_t group)
259{
260	struct ext4_group_desc *gdp;
261
262	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
263	return gdp->bg_inode_table |
264		(fs->super->s_feature_incompat
265		 & EXT4_FEATURE_INCOMPAT_64BIT ?
266		 (__u64) gdp->bg_inode_table_hi << 32 : 0);
267}
268
269/*
270 * Set the inode table block of a group
271 */
272void ext2fs_inode_table_loc_set(ext2_filsys fs, dgrp_t group, blk64_t blk)
273{
274	struct ext4_group_desc *gdp;
275
276	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
277	gdp->bg_inode_table = blk;
278	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
279		gdp->bg_inode_table_hi = (__u64) blk >> 32;
280}
281
282/*
283 * Return the free blocks count of a group
284 */
285__u32 ext2fs_bg_free_blocks_count(ext2_filsys fs, dgrp_t group)
286{
287	struct ext4_group_desc *gdp;
288
289	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
290	return gdp->bg_free_blocks_count |
291		(fs->super->s_feature_incompat
292		 & EXT4_FEATURE_INCOMPAT_64BIT ?
293		 (__u32) gdp->bg_free_blocks_count_hi << 16 : 0);
294}
295
296/*
297 * Set the free blocks count of a group
298 */
299void ext2fs_bg_free_blocks_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
300{
301	struct ext4_group_desc *gdp;
302
303	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
304	gdp->bg_free_blocks_count = n;
305
306	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
307		gdp->bg_free_blocks_count_hi = (__u32) n >> 16;
308}
309
310/*
311 * Return the free inodes count of a group
312 */
313__u32 ext2fs_bg_free_inodes_count(ext2_filsys fs, dgrp_t group)
314{
315	struct ext4_group_desc *gdp;
316
317	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
318	return gdp->bg_free_inodes_count |
319		(fs->super->s_feature_incompat
320		 & EXT4_FEATURE_INCOMPAT_64BIT ?
321		 (__u32) gdp->bg_free_inodes_count_hi << 16 : 0);
322}
323
324/*
325 * Set the free inodes count of a group
326 */
327void ext2fs_bg_free_inodes_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
328{
329	struct ext4_group_desc *gdp;
330
331	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
332	gdp->bg_free_inodes_count = n;
333	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
334		gdp->bg_free_inodes_count_hi = (__u32) n >> 16;
335}
336
337/*
338 * Return the used dirs count of a group
339 */
340__u32 ext2fs_bg_used_dirs_count(ext2_filsys fs, dgrp_t group)
341{
342	struct ext4_group_desc *gdp;
343
344	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
345	return gdp->bg_used_dirs_count |
346		(fs->super->s_feature_incompat
347		 & EXT4_FEATURE_INCOMPAT_64BIT ?
348		 (__u32) gdp->bg_used_dirs_count_hi << 16 : 0);
349}
350
351/*
352 * Set the used dirs count of a group
353 */
354void ext2fs_bg_used_dirs_count_set(ext2_filsys fs, dgrp_t group, __u32 n)
355{
356	struct ext4_group_desc *gdp;
357
358	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
359	gdp->bg_used_dirs_count = n;
360	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
361		gdp->bg_used_dirs_count_hi = (__u32) n >> 16;
362}
363
364/*
365 * Return the unused inodes count of a group
366 */
367__u32 ext2fs_bg_itable_unused(ext2_filsys fs, dgrp_t group)
368{
369	struct ext4_group_desc *gdp;
370
371	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
372	return gdp->bg_itable_unused |
373		(fs->super->s_feature_incompat
374		 & EXT4_FEATURE_INCOMPAT_64BIT ?
375		 (__u32) gdp->bg_itable_unused_hi << 16 : 0);
376}
377
378/*
379 * Set the unused inodes count of a group
380 */
381void ext2fs_bg_itable_unused_set(ext2_filsys fs, dgrp_t group, __u32 n)
382{
383	struct ext4_group_desc *gdp;
384
385	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
386	gdp->bg_itable_unused = n;
387	if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
388		gdp->bg_itable_unused_hi = (__u32) n >> 16;
389}
390
391/*
392 * Get the flags for this block group
393 */
394__u16 ext2fs_bg_flags(ext2_filsys fs, dgrp_t group)
395{
396	struct ext4_group_desc *gdp;
397
398	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
399	return gdp->bg_flags;
400}
401
402/*
403 * Zero out the flags for this block group
404 */
405void ext2fs_bg_flags_zap(ext2_filsys fs, dgrp_t group)
406{
407	struct ext4_group_desc *gdp;
408
409	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
410	gdp->bg_flags = 0;
411	return;
412}
413
414/*
415 * Get the value of a particular flag for this block group
416 */
417int ext2fs_bg_flags_test(ext2_filsys fs, dgrp_t group, __u16 bg_flag)
418{
419	struct ext4_group_desc *gdp;
420
421	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
422	return gdp->bg_flags & bg_flag;
423}
424
425/*
426 * Set a flag or set of flags for this block group
427 */
428void ext2fs_bg_flags_set(ext2_filsys fs, dgrp_t group, __u16 bg_flags)
429{
430	struct ext4_group_desc *gdp;
431
432	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
433	gdp->bg_flags |= bg_flags;
434	return;
435}
436
437/*
438 * Clear a flag or set of flags for this block group
439 */
440void ext2fs_bg_flags_clear(ext2_filsys fs, dgrp_t group, __u16 bg_flags)
441{
442	struct ext4_group_desc *gdp;
443
444	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
445	gdp->bg_flags &= ~bg_flags;
446	return;
447}
448
449/*
450 * Get the checksum for this block group
451 */
452__u16 ext2fs_bg_checksum(ext2_filsys fs, dgrp_t group)
453{
454	struct ext4_group_desc *gdp;
455
456	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
457	return gdp->bg_checksum;
458}
459
460/*
461 * Set the checksum for this block group to a previously calculated value
462 */
463void ext2fs_bg_checksum_set(ext2_filsys fs, dgrp_t group, __u16 checksum)
464{
465	struct ext4_group_desc *gdp;
466
467	gdp = ext4fs_group_desc(fs, fs->group_desc, group);
468	gdp->bg_checksum = checksum;
469	return;
470}
471
472/*
473 * Get the acl block of a file
474 */
475blk64_t ext2fs_file_acl_block(ext2_filsys fs, const struct ext2_inode *inode)
476{
477	blk64_t	blk = inode->i_file_acl;
478
479	if (fs && fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
480		blk |= ((__u64) inode->osd2.linux2.l_i_file_acl_high) << 32;
481	return blk;
482}
483
484/*
485 * Set the acl block of a file
486 */
487void ext2fs_file_acl_block_set(ext2_filsys fs, struct ext2_inode *inode,
488			       blk64_t blk)
489{
490	inode->i_file_acl = blk;
491	if (fs && fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
492		inode->osd2.linux2.l_i_file_acl_high = (__u64) blk >> 32;
493}
494
495