Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/ext2/balloc.c | |
4 | * | |
5 | * Copyright (C) 1992, 1993, 1994, 1995 | |
6 | * Remy Card (card@masi.ibp.fr) | |
7 | * Laboratoire MASI - Institut Blaise Pascal | |
8 | * Universite Pierre et Marie Curie (Paris VI) | |
9 | * | |
10 | * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993 | |
11 | * Big-endian to little-endian byte-swapping/bitmaps by | |
12 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
13 | */ | |
14 | ||
1da177e4 LT |
15 | #include "ext2.h" |
16 | #include <linux/quotaops.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
1da177e4 | 18 | #include <linux/sched.h> |
5b825c3a | 19 | #include <linux/cred.h> |
1da177e4 | 20 | #include <linux/buffer_head.h> |
16f7e0fe | 21 | #include <linux/capability.h> |
1da177e4 LT |
22 | |
23 | /* | |
24 | * balloc.c contains the blocks allocation and deallocation routines | |
25 | */ | |
26 | ||
27 | /* | |
28 | * The free blocks are managed by bitmaps. A file system contains several | |
29 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap | |
30 | * block for inodes, N blocks for the inode table and data blocks. | |
31 | * | |
32 | * The file system contains group descriptors which are located after the | |
33 | * super block. Each descriptor contains the number of the bitmap block and | |
34 | * the free blocks count in the block. The descriptors are loaded in memory | |
e627432c | 35 | * when a file system is mounted (see ext2_fill_super). |
1da177e4 LT |
36 | */ |
37 | ||
38 | ||
1da177e4 LT |
39 | struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, |
40 | unsigned int block_group, | |
41 | struct buffer_head ** bh) | |
42 | { | |
43 | unsigned long group_desc; | |
44 | unsigned long offset; | |
45 | struct ext2_group_desc * desc; | |
46 | struct ext2_sb_info *sbi = EXT2_SB(sb); | |
47 | ||
48 | if (block_group >= sbi->s_groups_count) { | |
372d1f3e DC |
49 | WARN(1, "block_group >= groups_count - " |
50 | "block_group = %d, groups_count = %lu", | |
51 | block_group, sbi->s_groups_count); | |
1da177e4 LT |
52 | |
53 | return NULL; | |
54 | } | |
55 | ||
56 | group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb); | |
57 | offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1); | |
58 | if (!sbi->s_group_desc[group_desc]) { | |
372d1f3e DC |
59 | WARN(1, "Group descriptor not loaded - " |
60 | "block_group = %d, group_desc = %lu, desc = %lu", | |
61 | block_group, group_desc, offset); | |
1da177e4 LT |
62 | return NULL; |
63 | } | |
64 | ||
65 | desc = (struct ext2_group_desc *) sbi->s_group_desc[group_desc]->b_data; | |
66 | if (bh) | |
67 | *bh = sbi->s_group_desc[group_desc]; | |
68 | return desc + offset; | |
69 | } | |
70 | ||
01584fa6 AK |
71 | static int ext2_valid_block_bitmap(struct super_block *sb, |
72 | struct ext2_group_desc *desc, | |
73 | unsigned int block_group, | |
74 | struct buffer_head *bh) | |
75 | { | |
76 | ext2_grpblk_t offset; | |
77 | ext2_grpblk_t next_zero_bit; | |
78 | ext2_fsblk_t bitmap_blk; | |
79 | ext2_fsblk_t group_first_block; | |
80 | ||
81 | group_first_block = ext2_group_first_block_no(sb, block_group); | |
82 | ||
83 | /* check whether block bitmap block number is set */ | |
84 | bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); | |
85 | offset = bitmap_blk - group_first_block; | |
86 | if (!ext2_test_bit(offset, bh->b_data)) | |
87 | /* bad block bitmap */ | |
88 | goto err_out; | |
89 | ||
90 | /* check whether the inode bitmap block number is set */ | |
91 | bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap); | |
92 | offset = bitmap_blk - group_first_block; | |
93 | if (!ext2_test_bit(offset, bh->b_data)) | |
94 | /* bad block bitmap */ | |
95 | goto err_out; | |
96 | ||
97 | /* check whether the inode table block number is set */ | |
98 | bitmap_blk = le32_to_cpu(desc->bg_inode_table); | |
99 | offset = bitmap_blk - group_first_block; | |
100 | next_zero_bit = ext2_find_next_zero_bit(bh->b_data, | |
101 | offset + EXT2_SB(sb)->s_itb_per_group, | |
102 | offset); | |
103 | if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group) | |
104 | /* good bitmap for inode tables */ | |
105 | return 1; | |
106 | ||
107 | err_out: | |
605afd60 | 108 | ext2_error(sb, __func__, |
01584fa6 AK |
109 | "Invalid block bitmap - " |
110 | "block_group = %d, block = %lu", | |
111 | block_group, bitmap_blk); | |
112 | return 0; | |
113 | } | |
114 | ||
1da177e4 | 115 | /* |
01584fa6 AK |
116 | * Read the bitmap for a given block_group,and validate the |
117 | * bits for block/inode/inode tables are set in the bitmaps | |
1da177e4 LT |
118 | * |
119 | * Return buffer_head on success or NULL in case of failure. | |
120 | */ | |
121 | static struct buffer_head * | |
122 | read_block_bitmap(struct super_block *sb, unsigned int block_group) | |
123 | { | |
124 | struct ext2_group_desc * desc; | |
125 | struct buffer_head * bh = NULL; | |
01584fa6 | 126 | ext2_fsblk_t bitmap_blk; |
28cf7559 | 127 | int ret; |
01584fa6 AK |
128 | |
129 | desc = ext2_get_group_desc(sb, block_group, NULL); | |
1da177e4 | 130 | if (!desc) |
01584fa6 AK |
131 | return NULL; |
132 | bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); | |
133 | bh = sb_getblk(sb, bitmap_blk); | |
134 | if (unlikely(!bh)) { | |
605afd60 | 135 | ext2_error(sb, __func__, |
01584fa6 AK |
136 | "Cannot read block bitmap - " |
137 | "block_group = %d, block_bitmap = %u", | |
138 | block_group, le32_to_cpu(desc->bg_block_bitmap)); | |
139 | return NULL; | |
140 | } | |
28cf7559 ZY |
141 | ret = bh_read(bh, 0); |
142 | if (ret > 0) | |
01584fa6 | 143 | return bh; |
28cf7559 | 144 | if (ret < 0) { |
01584fa6 | 145 | brelse(bh); |
605afd60 | 146 | ext2_error(sb, __func__, |
1da177e4 LT |
147 | "Cannot read block bitmap - " |
148 | "block_group = %d, block_bitmap = %u", | |
149 | block_group, le32_to_cpu(desc->bg_block_bitmap)); | |
01584fa6 AK |
150 | return NULL; |
151 | } | |
01584fa6 | 152 | |
8b915825 AK |
153 | ext2_valid_block_bitmap(sb, desc, block_group, bh); |
154 | /* | |
155 | * file system mounted not to panic on error, continue with corrupt | |
156 | * bitmap | |
157 | */ | |
0b832a4b | 158 | return bh; |
1da177e4 LT |
159 | } |
160 | ||
a686cd89 | 161 | static void group_adjust_blocks(struct super_block *sb, int group_no, |
1da177e4 LT |
162 | struct ext2_group_desc *desc, struct buffer_head *bh, int count) |
163 | { | |
164 | if (count) { | |
165 | struct ext2_sb_info *sbi = EXT2_SB(sb); | |
166 | unsigned free_blocks; | |
167 | ||
168 | spin_lock(sb_bgl_lock(sbi, group_no)); | |
169 | free_blocks = le16_to_cpu(desc->bg_free_blocks_count); | |
170 | desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count); | |
171 | spin_unlock(sb_bgl_lock(sbi, group_no)); | |
1da177e4 LT |
172 | mark_buffer_dirty(bh); |
173 | } | |
174 | } | |
175 | ||
a686cd89 MB |
176 | /* |
177 | * The reservation window structure operations | |
178 | * -------------------------------------------- | |
179 | * Operations include: | |
180 | * dump, find, add, remove, is_empty, find_next_reservable_window, etc. | |
181 | * | |
182 | * We use a red-black tree to represent per-filesystem reservation | |
183 | * windows. | |
184 | * | |
185 | */ | |
186 | ||
187 | /** | |
188 | * __rsv_window_dump() -- Dump the filesystem block allocation reservation map | |
c53ec7bc | 189 | * @root: root of per-filesystem reservation rb tree |
a686cd89 MB |
190 | * @verbose: verbose mode |
191 | * @fn: function which wishes to dump the reservation map | |
192 | * | |
193 | * If verbose is turned on, it will print the whole block reservation | |
194 | * windows(start, end). Otherwise, it will only print out the "bad" windows, | |
195 | * those windows that overlap with their immediate neighbors. | |
196 | */ | |
197 | #if 1 | |
198 | static void __rsv_window_dump(struct rb_root *root, int verbose, | |
199 | const char *fn) | |
200 | { | |
201 | struct rb_node *n; | |
202 | struct ext2_reserve_window_node *rsv, *prev; | |
203 | int bad; | |
204 | ||
205 | restart: | |
206 | n = rb_first(root); | |
207 | bad = 0; | |
208 | prev = NULL; | |
209 | ||
210 | printk("Block Allocation Reservation Windows Map (%s):\n", fn); | |
211 | while (n) { | |
212 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); | |
213 | if (verbose) | |
214 | printk("reservation window 0x%p " | |
215 | "start: %lu, end: %lu\n", | |
216 | rsv, rsv->rsv_start, rsv->rsv_end); | |
217 | if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { | |
218 | printk("Bad reservation %p (start >= end)\n", | |
219 | rsv); | |
220 | bad = 1; | |
221 | } | |
222 | if (prev && prev->rsv_end >= rsv->rsv_start) { | |
223 | printk("Bad reservation %p (prev->end >= start)\n", | |
224 | rsv); | |
225 | bad = 1; | |
226 | } | |
227 | if (bad) { | |
228 | if (!verbose) { | |
229 | printk("Restarting reservation walk in verbose mode\n"); | |
230 | verbose = 1; | |
231 | goto restart; | |
232 | } | |
233 | } | |
234 | n = rb_next(n); | |
235 | prev = rsv; | |
236 | } | |
237 | printk("Window map complete.\n"); | |
2c11619a | 238 | BUG_ON(bad); |
a686cd89 MB |
239 | } |
240 | #define rsv_window_dump(root, verbose) \ | |
605afd60 | 241 | __rsv_window_dump((root), (verbose), __func__) |
a686cd89 MB |
242 | #else |
243 | #define rsv_window_dump(root, verbose) do {} while (0) | |
244 | #endif | |
245 | ||
246 | /** | |
247 | * goal_in_my_reservation() | |
248 | * @rsv: inode's reservation window | |
249 | * @grp_goal: given goal block relative to the allocation block group | |
250 | * @group: the current allocation block group | |
251 | * @sb: filesystem super block | |
252 | * | |
253 | * Test if the given goal block (group relative) is within the file's | |
254 | * own block reservation window range. | |
255 | * | |
256 | * If the reservation window is outside the goal allocation group, return 0; | |
257 | * grp_goal (given goal block) could be -1, which means no specific | |
258 | * goal block. In this case, always return 1. | |
259 | * If the goal block is within the reservation window, return 1; | |
260 | * otherwise, return 0; | |
261 | */ | |
262 | static int | |
263 | goal_in_my_reservation(struct ext2_reserve_window *rsv, ext2_grpblk_t grp_goal, | |
264 | unsigned int group, struct super_block * sb) | |
265 | { | |
266 | ext2_fsblk_t group_first_block, group_last_block; | |
267 | ||
268 | group_first_block = ext2_group_first_block_no(sb, group); | |
90f3741c | 269 | group_last_block = ext2_group_last_block_no(sb, group); |
a686cd89 MB |
270 | |
271 | if ((rsv->_rsv_start > group_last_block) || | |
272 | (rsv->_rsv_end < group_first_block)) | |
273 | return 0; | |
274 | if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start) | |
275 | || (grp_goal + group_first_block > rsv->_rsv_end))) | |
276 | return 0; | |
277 | return 1; | |
278 | } | |
279 | ||
280 | /** | |
281 | * search_reserve_window() | |
c53ec7bc | 282 | * @root: root of reservation tree |
a686cd89 MB |
283 | * @goal: target allocation block |
284 | * | |
285 | * Find the reserved window which includes the goal, or the previous one | |
286 | * if the goal is not in any window. | |
287 | * Returns NULL if there are no windows or if all windows start after the goal. | |
288 | */ | |
289 | static struct ext2_reserve_window_node * | |
290 | search_reserve_window(struct rb_root *root, ext2_fsblk_t goal) | |
291 | { | |
292 | struct rb_node *n = root->rb_node; | |
293 | struct ext2_reserve_window_node *rsv; | |
294 | ||
295 | if (!n) | |
296 | return NULL; | |
297 | ||
298 | do { | |
299 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); | |
300 | ||
301 | if (goal < rsv->rsv_start) | |
302 | n = n->rb_left; | |
303 | else if (goal > rsv->rsv_end) | |
304 | n = n->rb_right; | |
305 | else | |
306 | return rsv; | |
307 | } while (n); | |
308 | /* | |
309 | * We've fallen off the end of the tree: the goal wasn't inside | |
310 | * any particular node. OK, the previous node must be to one | |
311 | * side of the interval containing the goal. If it's the RHS, | |
312 | * we need to back up one. | |
313 | */ | |
314 | if (rsv->rsv_start > goal) { | |
315 | n = rb_prev(&rsv->rsv_node); | |
316 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); | |
317 | } | |
318 | return rsv; | |
319 | } | |
320 | ||
321 | /* | |
322 | * ext2_rsv_window_add() -- Insert a window to the block reservation rb tree. | |
323 | * @sb: super block | |
324 | * @rsv: reservation window to add | |
325 | * | |
326 | * Must be called with rsv_lock held. | |
327 | */ | |
328 | void ext2_rsv_window_add(struct super_block *sb, | |
329 | struct ext2_reserve_window_node *rsv) | |
330 | { | |
331 | struct rb_root *root = &EXT2_SB(sb)->s_rsv_window_root; | |
332 | struct rb_node *node = &rsv->rsv_node; | |
333 | ext2_fsblk_t start = rsv->rsv_start; | |
334 | ||
335 | struct rb_node ** p = &root->rb_node; | |
336 | struct rb_node * parent = NULL; | |
337 | struct ext2_reserve_window_node *this; | |
338 | ||
339 | while (*p) | |
340 | { | |
341 | parent = *p; | |
342 | this = rb_entry(parent, struct ext2_reserve_window_node, rsv_node); | |
343 | ||
344 | if (start < this->rsv_start) | |
345 | p = &(*p)->rb_left; | |
346 | else if (start > this->rsv_end) | |
347 | p = &(*p)->rb_right; | |
348 | else { | |
349 | rsv_window_dump(root, 1); | |
350 | BUG(); | |
351 | } | |
352 | } | |
353 | ||
354 | rb_link_node(node, parent, p); | |
355 | rb_insert_color(node, root); | |
356 | } | |
357 | ||
358 | /** | |
359 | * rsv_window_remove() -- unlink a window from the reservation rb tree | |
360 | * @sb: super block | |
361 | * @rsv: reservation window to remove | |
362 | * | |
363 | * Mark the block reservation window as not allocated, and unlink it | |
364 | * from the filesystem reservation window rb tree. Must be called with | |
365 | * rsv_lock held. | |
366 | */ | |
367 | static void rsv_window_remove(struct super_block *sb, | |
368 | struct ext2_reserve_window_node *rsv) | |
369 | { | |
370 | rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; | |
371 | rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; | |
372 | rsv->rsv_alloc_hit = 0; | |
373 | rb_erase(&rsv->rsv_node, &EXT2_SB(sb)->s_rsv_window_root); | |
374 | } | |
375 | ||
376 | /* | |
377 | * rsv_is_empty() -- Check if the reservation window is allocated. | |
378 | * @rsv: given reservation window to check | |
379 | * | |
380 | * returns 1 if the end block is EXT2_RESERVE_WINDOW_NOT_ALLOCATED. | |
381 | */ | |
382 | static inline int rsv_is_empty(struct ext2_reserve_window *rsv) | |
383 | { | |
384 | /* a valid reservation end block could not be 0 */ | |
385 | return (rsv->_rsv_end == EXT2_RESERVE_WINDOW_NOT_ALLOCATED); | |
386 | } | |
387 | ||
388 | /** | |
389 | * ext2_init_block_alloc_info() | |
390 | * @inode: file inode structure | |
391 | * | |
392 | * Allocate and initialize the reservation window structure, and | |
393 | * link the window to the ext2 inode structure at last | |
394 | * | |
395 | * The reservation window structure is only dynamically allocated | |
396 | * and linked to ext2 inode the first time the open file | |
397 | * needs a new block. So, before every ext2_new_block(s) call, for | |
398 | * regular files, we should check whether the reservation window | |
399 | * structure exists or not. In the latter case, this function is called. | |
400 | * Fail to do so will result in block reservation being turned off for that | |
401 | * open file. | |
402 | * | |
403 | * This function is called from ext2_get_blocks_handle(), also called | |
404 | * when setting the reservation window size through ioctl before the file | |
405 | * is open for write (needs block allocation). | |
406 | * | |
407 | * Needs truncate_mutex protection prior to calling this function. | |
408 | */ | |
409 | void ext2_init_block_alloc_info(struct inode *inode) | |
410 | { | |
411 | struct ext2_inode_info *ei = EXT2_I(inode); | |
6e3d6ca0 | 412 | struct ext2_block_alloc_info *block_i; |
a686cd89 MB |
413 | struct super_block *sb = inode->i_sb; |
414 | ||
415 | block_i = kmalloc(sizeof(*block_i), GFP_NOFS); | |
416 | if (block_i) { | |
417 | struct ext2_reserve_window_node *rsv = &block_i->rsv_window_node; | |
418 | ||
419 | rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; | |
420 | rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; | |
421 | ||
422 | /* | |
423 | * if filesystem is mounted with NORESERVATION, the goal | |
424 | * reservation window size is set to zero to indicate | |
425 | * block reservation is off | |
426 | */ | |
427 | if (!test_opt(sb, RESERVATION)) | |
428 | rsv->rsv_goal_size = 0; | |
429 | else | |
430 | rsv->rsv_goal_size = EXT2_DEFAULT_RESERVE_BLOCKS; | |
431 | rsv->rsv_alloc_hit = 0; | |
432 | block_i->last_alloc_logical_block = 0; | |
433 | block_i->last_alloc_physical_block = 0; | |
434 | } | |
435 | ei->i_block_alloc_info = block_i; | |
436 | } | |
437 | ||
438 | /** | |
439 | * ext2_discard_reservation() | |
440 | * @inode: inode | |
441 | * | |
442 | * Discard(free) block reservation window on last file close, or truncate | |
443 | * or at last iput(). | |
444 | * | |
445 | * It is being called in three cases: | |
446 | * ext2_release_file(): last writer closes the file | |
447 | * ext2_clear_inode(): last iput(), when nobody links to this file. | |
448 | * ext2_truncate(): when the block indirect map is about to change. | |
449 | */ | |
450 | void ext2_discard_reservation(struct inode *inode) | |
451 | { | |
452 | struct ext2_inode_info *ei = EXT2_I(inode); | |
453 | struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info; | |
454 | struct ext2_reserve_window_node *rsv; | |
455 | spinlock_t *rsv_lock = &EXT2_SB(inode->i_sb)->s_rsv_window_lock; | |
456 | ||
457 | if (!block_i) | |
458 | return; | |
459 | ||
460 | rsv = &block_i->rsv_window_node; | |
461 | if (!rsv_is_empty(&rsv->rsv_window)) { | |
462 | spin_lock(rsv_lock); | |
463 | if (!rsv_is_empty(&rsv->rsv_window)) | |
464 | rsv_window_remove(inode->i_sb, rsv); | |
465 | spin_unlock(rsv_lock); | |
466 | } | |
467 | } | |
468 | ||
469 | /** | |
03248766 | 470 | * ext2_free_blocks() -- Free given blocks and update quota and i_blocks |
a686cd89 | 471 | * @inode: inode |
4907cb7b | 472 | * @block: start physical block to free |
a686cd89 MB |
473 | * @count: number of blocks to free |
474 | */ | |
2ebc736c GO |
475 | void ext2_free_blocks(struct inode * inode, ext2_fsblk_t block, |
476 | unsigned long count) | |
1da177e4 LT |
477 | { |
478 | struct buffer_head *bitmap_bh = NULL; | |
479 | struct buffer_head * bh2; | |
480 | unsigned long block_group; | |
481 | unsigned long bit; | |
482 | unsigned long i; | |
483 | unsigned long overflow; | |
484 | struct super_block * sb = inode->i_sb; | |
485 | struct ext2_sb_info * sbi = EXT2_SB(sb); | |
486 | struct ext2_group_desc * desc; | |
487 | struct ext2_super_block * es = sbi->s_es; | |
488 | unsigned freed = 0, group_freed; | |
489 | ||
b6aeffc5 | 490 | if (!ext2_data_block_valid(sbi, block, count)) { |
1da177e4 LT |
491 | ext2_error (sb, "ext2_free_blocks", |
492 | "Freeing blocks not in datazone - " | |
493 | "block = %lu, count = %lu", block, count); | |
494 | goto error_return; | |
495 | } | |
496 | ||
497 | ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); | |
498 | ||
499 | do_more: | |
500 | overflow = 0; | |
501 | block_group = (block - le32_to_cpu(es->s_first_data_block)) / | |
502 | EXT2_BLOCKS_PER_GROUP(sb); | |
503 | bit = (block - le32_to_cpu(es->s_first_data_block)) % | |
504 | EXT2_BLOCKS_PER_GROUP(sb); | |
505 | /* | |
506 | * Check to see if we are freeing blocks across a group | |
507 | * boundary. | |
508 | */ | |
509 | if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) { | |
510 | overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb); | |
511 | count -= overflow; | |
512 | } | |
513 | brelse(bitmap_bh); | |
514 | bitmap_bh = read_block_bitmap(sb, block_group); | |
515 | if (!bitmap_bh) | |
516 | goto error_return; | |
517 | ||
518 | desc = ext2_get_group_desc (sb, block_group, &bh2); | |
519 | if (!desc) | |
520 | goto error_return; | |
521 | ||
522 | if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) || | |
523 | in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) || | |
524 | in_range (block, le32_to_cpu(desc->bg_inode_table), | |
525 | sbi->s_itb_per_group) || | |
526 | in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), | |
7f0adaec | 527 | sbi->s_itb_per_group)) { |
1da177e4 LT |
528 | ext2_error (sb, "ext2_free_blocks", |
529 | "Freeing blocks in system zones - " | |
530 | "Block = %lu, count = %lu", | |
531 | block, count); | |
7f0adaec AK |
532 | goto error_return; |
533 | } | |
1da177e4 LT |
534 | |
535 | for (i = 0, group_freed = 0; i < count; i++) { | |
536 | if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group), | |
537 | bit + i, bitmap_bh->b_data)) { | |
605afd60 | 538 | ext2_error(sb, __func__, |
1da177e4 LT |
539 | "bit already cleared for block %lu", block + i); |
540 | } else { | |
541 | group_freed++; | |
542 | } | |
543 | } | |
544 | ||
545 | mark_buffer_dirty(bitmap_bh); | |
1751e8a6 | 546 | if (sb->s_flags & SB_SYNCHRONOUS) |
1da177e4 LT |
547 | sync_dirty_buffer(bitmap_bh); |
548 | ||
a686cd89 | 549 | group_adjust_blocks(sb, block_group, desc, bh2, group_freed); |
1da177e4 LT |
550 | freed += group_freed; |
551 | ||
552 | if (overflow) { | |
553 | block += count; | |
554 | count = overflow; | |
555 | goto do_more; | |
556 | } | |
557 | error_return: | |
558 | brelse(bitmap_bh); | |
8e3dffc6 | 559 | if (freed) { |
712ddc52 | 560 | percpu_counter_add(&sbi->s_freeblocks_counter, freed); |
8e3dffc6 WS |
561 | dquot_free_block_nodirty(inode, freed); |
562 | mark_inode_dirty(inode); | |
563 | } | |
1da177e4 LT |
564 | } |
565 | ||
a686cd89 MB |
566 | /** |
567 | * bitmap_search_next_usable_block() | |
568 | * @start: the starting block (group relative) of the search | |
569 | * @bh: bufferhead contains the block group bitmap | |
570 | * @maxblocks: the ending block (group relative) of the reservation | |
571 | * | |
572 | * The bitmap search --- search forward through the actual bitmap on disk until | |
573 | * we find a bit free. | |
574 | */ | |
575 | static ext2_grpblk_t | |
576 | bitmap_search_next_usable_block(ext2_grpblk_t start, struct buffer_head *bh, | |
577 | ext2_grpblk_t maxblocks) | |
1da177e4 | 578 | { |
a686cd89 | 579 | ext2_grpblk_t next; |
1da177e4 | 580 | |
a686cd89 MB |
581 | next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start); |
582 | if (next >= maxblocks) | |
583 | return -1; | |
584 | return next; | |
585 | } | |
1da177e4 | 586 | |
a686cd89 MB |
587 | /** |
588 | * find_next_usable_block() | |
589 | * @start: the starting block (group relative) to find next | |
590 | * allocatable block in bitmap. | |
591 | * @bh: bufferhead contains the block group bitmap | |
592 | * @maxblocks: the ending block (group relative) for the search | |
593 | * | |
594 | * Find an allocatable block in a bitmap. We perform the "most | |
595 | * appropriate allocation" algorithm of looking for a free block near | |
596 | * the initial goal; then for a free byte somewhere in the bitmap; | |
597 | * then for any free bit in the bitmap. | |
598 | */ | |
599 | static ext2_grpblk_t | |
600 | find_next_usable_block(int start, struct buffer_head *bh, int maxblocks) | |
601 | { | |
602 | ext2_grpblk_t here, next; | |
603 | char *p, *r; | |
604 | ||
605 | if (start > 0) { | |
1da177e4 LT |
606 | /* |
607 | * The goal was occupied; search forward for a free | |
608 | * block within the next XX blocks. | |
609 | * | |
610 | * end_goal is more or less random, but it has to be | |
611 | * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the | |
612 | * next 64-bit boundary is simple.. | |
613 | */ | |
a686cd89 MB |
614 | ext2_grpblk_t end_goal = (start + 63) & ~63; |
615 | if (end_goal > maxblocks) | |
616 | end_goal = maxblocks; | |
617 | here = ext2_find_next_zero_bit(bh->b_data, end_goal, start); | |
618 | if (here < end_goal) | |
619 | return here; | |
620 | ext2_debug("Bit not found near goal\n"); | |
621 | } | |
622 | ||
623 | here = start; | |
624 | if (here < 0) | |
625 | here = 0; | |
626 | ||
627 | p = ((char *)bh->b_data) + (here >> 3); | |
628 | r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3)); | |
629 | next = (r - ((char *)bh->b_data)) << 3; | |
630 | ||
631 | if (next < maxblocks && next >= here) | |
632 | return next; | |
633 | ||
634 | here = bitmap_search_next_usable_block(here, bh, maxblocks); | |
635 | return here; | |
636 | } | |
637 | ||
26f78b7a | 638 | /** |
a686cd89 MB |
639 | * ext2_try_to_allocate() |
640 | * @sb: superblock | |
a686cd89 MB |
641 | * @group: given allocation block group |
642 | * @bitmap_bh: bufferhead holds the block bitmap | |
643 | * @grp_goal: given target block within the group | |
644 | * @count: target number of blocks to allocate | |
645 | * @my_rsv: reservation window | |
646 | * | |
647 | * Attempt to allocate blocks within a give range. Set the range of allocation | |
648 | * first, then find the first free bit(s) from the bitmap (within the range), | |
649 | * and at last, allocate the blocks by claiming the found free bit as allocated. | |
650 | * | |
651 | * To set the range of this allocation: | |
652 | * if there is a reservation window, only try to allocate block(s) | |
653 | * from the file's own reservation window; | |
654 | * Otherwise, the allocation range starts from the give goal block, | |
655 | * ends at the block group's last block. | |
656 | * | |
657 | * If we failed to allocate the desired block then we may end up crossing to a | |
658 | * new bitmap. | |
659 | */ | |
660 | static int | |
661 | ext2_try_to_allocate(struct super_block *sb, int group, | |
662 | struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, | |
663 | unsigned long *count, | |
664 | struct ext2_reserve_window *my_rsv) | |
665 | { | |
90f3741c CX |
666 | ext2_fsblk_t group_first_block = ext2_group_first_block_no(sb, group); |
667 | ext2_fsblk_t group_last_block = ext2_group_last_block_no(sb, group); | |
b41b98e1 | 668 | ext2_grpblk_t start, end; |
a686cd89 MB |
669 | unsigned long num = 0; |
670 | ||
cf4eb321 JK |
671 | start = 0; |
672 | end = group_last_block - group_first_block + 1; | |
a686cd89 MB |
673 | /* we do allocation within the reservation window if we have a window */ |
674 | if (my_rsv) { | |
a686cd89 MB |
675 | if (my_rsv->_rsv_start >= group_first_block) |
676 | start = my_rsv->_rsv_start - group_first_block; | |
cf4eb321 JK |
677 | if (my_rsv->_rsv_end < group_last_block) |
678 | end = my_rsv->_rsv_end - group_first_block + 1; | |
679 | if (grp_goal < start || grp_goal >= end) | |
a686cd89 | 680 | grp_goal = -1; |
a686cd89 | 681 | } |
a686cd89 MB |
682 | BUG_ON(start > EXT2_BLOCKS_PER_GROUP(sb)); |
683 | ||
a686cd89 MB |
684 | if (grp_goal < 0) { |
685 | grp_goal = find_next_usable_block(start, bitmap_bh, end); | |
686 | if (grp_goal < 0) | |
687 | goto fail_access; | |
688 | if (!my_rsv) { | |
689 | int i; | |
690 | ||
691 | for (i = 0; i < 7 && grp_goal > start && | |
692 | !ext2_test_bit(grp_goal - 1, | |
693 | bitmap_bh->b_data); | |
694 | i++, grp_goal--) | |
695 | ; | |
696 | } | |
697 | } | |
a686cd89 | 698 | |
44dd6161 CX |
699 | for (; num < *count && grp_goal < end; grp_goal++) { |
700 | if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), | |
a686cd89 | 701 | grp_goal, bitmap_bh->b_data)) { |
44dd6161 CX |
702 | if (num == 0) |
703 | continue; | |
704 | break; | |
705 | } | |
a686cd89 | 706 | num++; |
a686cd89 | 707 | } |
44dd6161 CX |
708 | |
709 | if (num == 0) | |
710 | goto fail_access; | |
711 | ||
a686cd89 MB |
712 | *count = num; |
713 | return grp_goal - num; | |
714 | fail_access: | |
a686cd89 MB |
715 | return -1; |
716 | } | |
717 | ||
718 | /** | |
df1ae36a MWO |
719 | * find_next_reservable_window - Find a reservable space within the given range. |
720 | * @search_head: The list to search. | |
721 | * @my_rsv: The reservation we're currently using. | |
722 | * @sb: The super block. | |
723 | * @start_block: The first block we consider to start the real search from | |
724 | * @last_block: The maximum block number that our goal reservable space | |
725 | * could start from. | |
a686cd89 | 726 | * |
df1ae36a MWO |
727 | * It does not allocate the reservation window: alloc_new_reservation() |
728 | * will do the work later. | |
a686cd89 | 729 | * |
df1ae36a MWO |
730 | * We search the given range, rather than the whole reservation double |
731 | * linked list, (start_block, last_block) to find a free region that is | |
732 | * of my size and has not been reserved. | |
a686cd89 | 733 | * |
df1ae36a MWO |
734 | * @search_head is not necessarily the list head of the whole filesystem. |
735 | * We have both head and @start_block to assist the search for the | |
736 | * reservable space. The list starts from head, but we will shift to | |
737 | * the place where start_block is, then start from there, when looking | |
738 | * for a reservable space. | |
a686cd89 | 739 | * |
df1ae36a MWO |
740 | * @last_block is normally the last block in this group. The search will end |
741 | * when we found the start of next possible reservable space is out | |
742 | * of this boundary. This could handle the cross boundary reservation | |
743 | * window request. | |
a686cd89 | 744 | * |
df1ae36a MWO |
745 | * Return: -1 if we could not find a range of sufficient size. If we could, |
746 | * return 0 and fill in @my_rsv with the range information. | |
a686cd89 MB |
747 | */ |
748 | static int find_next_reservable_window( | |
749 | struct ext2_reserve_window_node *search_head, | |
750 | struct ext2_reserve_window_node *my_rsv, | |
751 | struct super_block * sb, | |
752 | ext2_fsblk_t start_block, | |
753 | ext2_fsblk_t last_block) | |
754 | { | |
755 | struct rb_node *next; | |
756 | struct ext2_reserve_window_node *rsv, *prev; | |
757 | ext2_fsblk_t cur; | |
758 | int size = my_rsv->rsv_goal_size; | |
759 | ||
760 | /* TODO: make the start of the reservation window byte-aligned */ | |
761 | /* cur = *start_block & ~7;*/ | |
762 | cur = start_block; | |
763 | rsv = search_head; | |
764 | if (!rsv) | |
765 | return -1; | |
766 | ||
767 | while (1) { | |
768 | if (cur <= rsv->rsv_end) | |
769 | cur = rsv->rsv_end + 1; | |
770 | ||
771 | /* TODO? | |
772 | * in the case we could not find a reservable space | |
773 | * that is what is expected, during the re-search, we could | |
774 | * remember what's the largest reservable space we could have | |
775 | * and return that one. | |
776 | * | |
777 | * For now it will fail if we could not find the reservable | |
778 | * space with expected-size (or more)... | |
779 | */ | |
780 | if (cur > last_block) | |
781 | return -1; /* fail */ | |
782 | ||
783 | prev = rsv; | |
784 | next = rb_next(&rsv->rsv_node); | |
785 | rsv = rb_entry(next,struct ext2_reserve_window_node,rsv_node); | |
786 | ||
1da177e4 | 787 | /* |
a686cd89 MB |
788 | * Reached the last reservation, we can just append to the |
789 | * previous one. | |
1da177e4 | 790 | */ |
a686cd89 MB |
791 | if (!next) |
792 | break; | |
793 | ||
794 | if (cur + size <= rsv->rsv_start) { | |
795 | /* | |
796 | * Found a reserveable space big enough. We could | |
797 | * have a reservation across the group boundary here | |
798 | */ | |
799 | break; | |
800 | } | |
1da177e4 | 801 | } |
a686cd89 MB |
802 | /* |
803 | * we come here either : | |
804 | * when we reach the end of the whole list, | |
805 | * and there is empty reservable space after last entry in the list. | |
806 | * append it to the end of the list. | |
807 | * | |
808 | * or we found one reservable space in the middle of the list, | |
809 | * return the reservation window that we could append to. | |
810 | * succeed. | |
811 | */ | |
812 | ||
813 | if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) | |
814 | rsv_window_remove(sb, my_rsv); | |
815 | ||
816 | /* | |
25985edc | 817 | * Let's book the whole available window for now. We will check the |
a686cd89 MB |
818 | * disk bitmap later and then, if there are free blocks then we adjust |
819 | * the window size if it's larger than requested. | |
820 | * Otherwise, we will remove this node from the tree next time | |
821 | * call find_next_reservable_window. | |
822 | */ | |
823 | my_rsv->rsv_start = cur; | |
824 | my_rsv->rsv_end = cur + size - 1; | |
825 | my_rsv->rsv_alloc_hit = 0; | |
826 | ||
827 | if (prev != my_rsv) | |
828 | ext2_rsv_window_add(sb, my_rsv); | |
829 | ||
830 | return 0; | |
831 | } | |
832 | ||
833 | /** | |
df1ae36a MWO |
834 | * alloc_new_reservation - Allocate a new reservation window. |
835 | * @my_rsv: The reservation we're currently using. | |
836 | * @grp_goal: The goal block relative to the start of the group. | |
837 | * @sb: The super block. | |
838 | * @group: The group we are trying to allocate in. | |
839 | * @bitmap_bh: The block group block bitmap. | |
a686cd89 | 840 | * |
df1ae36a MWO |
841 | * To make a new reservation, we search part of the filesystem reservation |
842 | * list (the list inside the group). We try to allocate a new | |
843 | * reservation window near @grp_goal, or the beginning of the | |
844 | * group, if @grp_goal is negative. | |
a686cd89 | 845 | * |
df1ae36a MWO |
846 | * We first find a reservable space after the goal, then from there, |
847 | * we check the bitmap for the first free block after it. If there is | |
848 | * no free block until the end of group, then the whole group is full, | |
849 | * we failed. Otherwise, check if the free block is inside the expected | |
850 | * reservable space, if so, we succeed. | |
a686cd89 | 851 | * |
df1ae36a MWO |
852 | * If the first free block is outside the reservable space, then start |
853 | * from the first free block, we search for next available space, and | |
854 | * go on. | |
a686cd89 | 855 | * |
df1ae36a MWO |
856 | * on succeed, a new reservation will be found and inserted into the |
857 | * list. It contains at least one free block, and it does not overlap | |
858 | * with other reservation windows. | |
a686cd89 | 859 | * |
df1ae36a MWO |
860 | * Return: 0 on success, -1 if we failed to find a reservation window |
861 | * in this group | |
a686cd89 MB |
862 | */ |
863 | static int alloc_new_reservation(struct ext2_reserve_window_node *my_rsv, | |
864 | ext2_grpblk_t grp_goal, struct super_block *sb, | |
865 | unsigned int group, struct buffer_head *bitmap_bh) | |
866 | { | |
867 | struct ext2_reserve_window_node *search_head; | |
868 | ext2_fsblk_t group_first_block, group_end_block, start_block; | |
869 | ext2_grpblk_t first_free_block; | |
870 | struct rb_root *fs_rsv_root = &EXT2_SB(sb)->s_rsv_window_root; | |
871 | unsigned long size; | |
872 | int ret; | |
873 | spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock; | |
874 | ||
875 | group_first_block = ext2_group_first_block_no(sb, group); | |
90f3741c | 876 | group_end_block = ext2_group_last_block_no(sb, group); |
1da177e4 | 877 | |
a686cd89 MB |
878 | if (grp_goal < 0) |
879 | start_block = group_first_block; | |
880 | else | |
881 | start_block = grp_goal + group_first_block; | |
882 | ||
883 | size = my_rsv->rsv_goal_size; | |
884 | ||
885 | if (!rsv_is_empty(&my_rsv->rsv_window)) { | |
886 | /* | |
887 | * if the old reservation is cross group boundary | |
888 | * and if the goal is inside the old reservation window, | |
889 | * we will come here when we just failed to allocate from | |
890 | * the first part of the window. We still have another part | |
891 | * that belongs to the next group. In this case, there is no | |
892 | * point to discard our window and try to allocate a new one | |
893 | * in this group(which will fail). we should | |
894 | * keep the reservation window, just simply move on. | |
895 | * | |
896 | * Maybe we could shift the start block of the reservation | |
897 | * window to the first block of next group. | |
1da177e4 | 898 | */ |
a686cd89 MB |
899 | |
900 | if ((my_rsv->rsv_start <= group_end_block) && | |
901 | (my_rsv->rsv_end > group_end_block) && | |
902 | (start_block >= my_rsv->rsv_start)) | |
903 | return -1; | |
904 | ||
905 | if ((my_rsv->rsv_alloc_hit > | |
906 | (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { | |
907 | /* | |
908 | * if the previously allocation hit ratio is | |
909 | * greater than 1/2, then we double the size of | |
910 | * the reservation window the next time, | |
911 | * otherwise we keep the same size window | |
912 | */ | |
913 | size = size * 2; | |
914 | if (size > EXT2_MAX_RESERVE_BLOCKS) | |
915 | size = EXT2_MAX_RESERVE_BLOCKS; | |
916 | my_rsv->rsv_goal_size= size; | |
917 | } | |
1da177e4 LT |
918 | } |
919 | ||
a686cd89 MB |
920 | spin_lock(rsv_lock); |
921 | /* | |
922 | * shift the search start to the window near the goal block | |
923 | */ | |
924 | search_head = search_reserve_window(fs_rsv_root, start_block); | |
925 | ||
926 | /* | |
927 | * find_next_reservable_window() simply finds a reservable window | |
928 | * inside the given range(start_block, group_end_block). | |
929 | * | |
930 | * To make sure the reservation window has a free bit inside it, we | |
931 | * need to check the bitmap after we found a reservable window. | |
932 | */ | |
933 | retry: | |
934 | ret = find_next_reservable_window(search_head, my_rsv, sb, | |
935 | start_block, group_end_block); | |
936 | ||
937 | if (ret == -1) { | |
938 | if (!rsv_is_empty(&my_rsv->rsv_window)) | |
939 | rsv_window_remove(sb, my_rsv); | |
940 | spin_unlock(rsv_lock); | |
941 | return -1; | |
1da177e4 | 942 | } |
a686cd89 MB |
943 | |
944 | /* | |
945 | * On success, find_next_reservable_window() returns the | |
946 | * reservation window where there is a reservable space after it. | |
947 | * Before we reserve this reservable space, we need | |
948 | * to make sure there is at least a free block inside this region. | |
949 | * | |
950 | * Search the first free bit on the block bitmap. Search starts from | |
951 | * the start block of the reservable space we just found. | |
952 | */ | |
953 | spin_unlock(rsv_lock); | |
954 | first_free_block = bitmap_search_next_usable_block( | |
955 | my_rsv->rsv_start - group_first_block, | |
956 | bitmap_bh, group_end_block - group_first_block + 1); | |
957 | ||
958 | if (first_free_block < 0) { | |
959 | /* | |
960 | * no free block left on the bitmap, no point | |
961 | * to reserve the space. return failed. | |
962 | */ | |
963 | spin_lock(rsv_lock); | |
964 | if (!rsv_is_empty(&my_rsv->rsv_window)) | |
965 | rsv_window_remove(sb, my_rsv); | |
966 | spin_unlock(rsv_lock); | |
967 | return -1; /* failed */ | |
968 | } | |
969 | ||
970 | start_block = first_free_block + group_first_block; | |
971 | /* | |
972 | * check if the first free block is within the | |
973 | * free space we just reserved | |
974 | */ | |
975 | if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end) | |
976 | return 0; /* success */ | |
977 | /* | |
978 | * if the first free bit we found is out of the reservable space | |
979 | * continue search for next reservable space, | |
980 | * start from where the free block is, | |
981 | * we also shift the list head to where we stopped last time | |
982 | */ | |
983 | search_head = my_rsv; | |
984 | spin_lock(rsv_lock); | |
985 | goto retry; | |
986 | } | |
987 | ||
988 | /** | |
989 | * try_to_extend_reservation() | |
990 | * @my_rsv: given reservation window | |
991 | * @sb: super block | |
992 | * @size: the delta to extend | |
993 | * | |
994 | * Attempt to expand the reservation window large enough to have | |
995 | * required number of free blocks | |
996 | * | |
997 | * Since ext2_try_to_allocate() will always allocate blocks within | |
998 | * the reservation window range, if the window size is too small, | |
999 | * multiple blocks allocation has to stop at the end of the reservation | |
1000 | * window. To make this more efficient, given the total number of | |
1001 | * blocks needed and the current size of the window, we try to | |
1002 | * expand the reservation window size if necessary on a best-effort | |
1003 | * basis before ext2_new_blocks() tries to allocate blocks. | |
1004 | */ | |
1005 | static void try_to_extend_reservation(struct ext2_reserve_window_node *my_rsv, | |
1006 | struct super_block *sb, int size) | |
1007 | { | |
1008 | struct ext2_reserve_window_node *next_rsv; | |
1009 | struct rb_node *next; | |
1010 | spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock; | |
1011 | ||
1012 | if (!spin_trylock(rsv_lock)) | |
1013 | return; | |
1014 | ||
1015 | next = rb_next(&my_rsv->rsv_node); | |
1016 | ||
1017 | if (!next) | |
1018 | my_rsv->rsv_end += size; | |
1019 | else { | |
1020 | next_rsv = rb_entry(next, struct ext2_reserve_window_node, rsv_node); | |
1021 | ||
1022 | if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) | |
1023 | my_rsv->rsv_end += size; | |
1024 | else | |
1025 | my_rsv->rsv_end = next_rsv->rsv_start - 1; | |
1026 | } | |
1027 | spin_unlock(rsv_lock); | |
1028 | } | |
1029 | ||
1030 | /** | |
1031 | * ext2_try_to_allocate_with_rsv() | |
1032 | * @sb: superblock | |
1033 | * @group: given allocation block group | |
1034 | * @bitmap_bh: bufferhead holds the block bitmap | |
1035 | * @grp_goal: given target block within the group | |
1036 | * @count: target number of blocks to allocate | |
1037 | * @my_rsv: reservation window | |
1038 | * | |
1039 | * This is the main function used to allocate a new block and its reservation | |
1040 | * window. | |
1041 | * | |
1042 | * Each time when a new block allocation is need, first try to allocate from | |
1043 | * its own reservation. If it does not have a reservation window, instead of | |
1044 | * looking for a free bit on bitmap first, then look up the reservation list to | |
1045 | * see if it is inside somebody else's reservation window, we try to allocate a | |
1046 | * reservation window for it starting from the goal first. Then do the block | |
1047 | * allocation within the reservation window. | |
1048 | * | |
1049 | * This will avoid keeping on searching the reservation list again and | |
1050 | * again when somebody is looking for a free block (without | |
1051 | * reservation), and there are lots of free blocks, but they are all | |
1052 | * being reserved. | |
1053 | * | |
1054 | * We use a red-black tree for the per-filesystem reservation list. | |
1055 | */ | |
1056 | static ext2_grpblk_t | |
1057 | ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group, | |
1058 | struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, | |
1059 | struct ext2_reserve_window_node * my_rsv, | |
1060 | unsigned long *count) | |
1061 | { | |
1062 | ext2_fsblk_t group_first_block, group_last_block; | |
1063 | ext2_grpblk_t ret = 0; | |
1064 | unsigned long num = *count; | |
1065 | ||
1066 | /* | |
1067 | * we don't deal with reservation when | |
1068 | * filesystem is mounted without reservation | |
1069 | * or the file is not a regular file | |
1070 | * or last attempt to allocate a block with reservation turned on failed | |
1071 | */ | |
1072 | if (my_rsv == NULL) { | |
1073 | return ext2_try_to_allocate(sb, group, bitmap_bh, | |
1074 | grp_goal, count, NULL); | |
1075 | } | |
1076 | /* | |
1077 | * grp_goal is a group relative block number (if there is a goal) | |
1078 | * 0 <= grp_goal < EXT2_BLOCKS_PER_GROUP(sb) | |
1079 | * first block is a filesystem wide block number | |
1080 | * first block is the block number of the first block in this group | |
1081 | */ | |
1082 | group_first_block = ext2_group_first_block_no(sb, group); | |
90f3741c | 1083 | group_last_block = ext2_group_last_block_no(sb, group); |
a686cd89 MB |
1084 | |
1085 | /* | |
1086 | * Basically we will allocate a new block from inode's reservation | |
1087 | * window. | |
1088 | * | |
1089 | * We need to allocate a new reservation window, if: | |
1090 | * a) inode does not have a reservation window; or | |
1091 | * b) last attempt to allocate a block from existing reservation | |
1092 | * failed; or | |
1093 | * c) we come here with a goal and with a reservation window | |
1094 | * | |
1095 | * We do not need to allocate a new reservation window if we come here | |
1096 | * at the beginning with a goal and the goal is inside the window, or | |
1097 | * we don't have a goal but already have a reservation window. | |
1098 | * then we could go to allocate from the reservation window directly. | |
1099 | */ | |
1100 | while (1) { | |
1101 | if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || | |
1102 | !goal_in_my_reservation(&my_rsv->rsv_window, | |
1103 | grp_goal, group, sb)) { | |
1104 | if (my_rsv->rsv_goal_size < *count) | |
1105 | my_rsv->rsv_goal_size = *count; | |
1106 | ret = alloc_new_reservation(my_rsv, grp_goal, sb, | |
1107 | group, bitmap_bh); | |
1108 | if (ret < 0) | |
1109 | break; /* failed */ | |
1110 | ||
1111 | if (!goal_in_my_reservation(&my_rsv->rsv_window, | |
1112 | grp_goal, group, sb)) | |
1113 | grp_goal = -1; | |
1114 | } else if (grp_goal >= 0) { | |
1115 | int curr = my_rsv->rsv_end - | |
1116 | (grp_goal + group_first_block) + 1; | |
1117 | ||
1118 | if (curr < *count) | |
1119 | try_to_extend_reservation(my_rsv, sb, | |
1120 | *count - curr); | |
1121 | } | |
1122 | ||
1123 | if ((my_rsv->rsv_start > group_last_block) || | |
1124 | (my_rsv->rsv_end < group_first_block)) { | |
9bc6fc33 YB |
1125 | ext2_error(sb, __func__, |
1126 | "Reservation out of group %u range goal %d fsb[%lu,%lu] rsv[%lu, %lu]", | |
1127 | group, grp_goal, group_first_block, | |
1128 | group_last_block, my_rsv->rsv_start, | |
1129 | my_rsv->rsv_end); | |
a686cd89 | 1130 | rsv_window_dump(&EXT2_SB(sb)->s_rsv_window_root, 1); |
9bc6fc33 | 1131 | return -1; |
a686cd89 MB |
1132 | } |
1133 | ret = ext2_try_to_allocate(sb, group, bitmap_bh, grp_goal, | |
1134 | &num, &my_rsv->rsv_window); | |
1135 | if (ret >= 0) { | |
1136 | my_rsv->rsv_alloc_hit += num; | |
1137 | *count = num; | |
1138 | break; /* succeed */ | |
1139 | } | |
1140 | num = *count; | |
1141 | } | |
1142 | return ret; | |
1143 | } | |
1144 | ||
1145 | /** | |
1146 | * ext2_has_free_blocks() | |
1147 | * @sbi: in-core super block structure. | |
1148 | * | |
1149 | * Check if filesystem has at least 1 free block available for allocation. | |
1150 | */ | |
1151 | static int ext2_has_free_blocks(struct ext2_sb_info *sbi) | |
1152 | { | |
1153 | ext2_fsblk_t free_blocks, root_blocks; | |
1154 | ||
1155 | free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); | |
1156 | root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); | |
1157 | if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && | |
b8a9f9e1 EB |
1158 | !uid_eq(sbi->s_resuid, current_fsuid()) && |
1159 | (gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) || | |
1160 | !in_group_p (sbi->s_resgid))) { | |
a686cd89 MB |
1161 | return 0; |
1162 | } | |
1163 | return 1; | |
1da177e4 LT |
1164 | } |
1165 | ||
ff0031d8 CM |
1166 | /* |
1167 | * Returns 1 if the passed-in block region is valid; 0 if some part overlaps | |
1fe03415 | 1168 | * with filesystem metadata blocks. |
ff0031d8 CM |
1169 | */ |
1170 | int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, | |
1171 | unsigned int count) | |
1172 | { | |
1173 | if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || | |
e5d39597 CX |
1174 | (start_blk + count - 1 < start_blk) || |
1175 | (start_blk + count - 1 >= le32_to_cpu(sbi->s_es->s_blocks_count))) | |
ff0031d8 CM |
1176 | return 0; |
1177 | ||
1178 | /* Ensure we do not step over superblock */ | |
1179 | if ((start_blk <= sbi->s_sb_block) && | |
e5d39597 | 1180 | (start_blk + count - 1 >= sbi->s_sb_block)) |
ff0031d8 CM |
1181 | return 0; |
1182 | ||
ff0031d8 CM |
1183 | return 1; |
1184 | } | |
1185 | ||
1da177e4 | 1186 | /* |
a686cd89 MB |
1187 | * ext2_new_blocks() -- core block(s) allocation function |
1188 | * @inode: file inode | |
1189 | * @goal: given target block(filesystem wide) | |
1190 | * @count: target number of blocks to allocate | |
1191 | * @errp: error code | |
b450159d | 1192 | * @flags: allocate flags |
a686cd89 MB |
1193 | * |
1194 | * ext2_new_blocks uses a goal block to assist allocation. If the goal is | |
1da177e4 LT |
1195 | * free, or there is a free block within 32 blocks of the goal, that block |
1196 | * is allocated. Otherwise a forward search is made for a free block; within | |
1197 | * each block group the search first looks for an entire free byte in the block | |
1198 | * bitmap, and then for any free bit if that fails. | |
1199 | * This function also updates quota and i_blocks field. | |
1200 | */ | |
a686cd89 | 1201 | ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, |
b450159d | 1202 | unsigned long *count, int *errp, unsigned int flags) |
1da177e4 LT |
1203 | { |
1204 | struct buffer_head *bitmap_bh = NULL; | |
a686cd89 MB |
1205 | struct buffer_head *gdp_bh; |
1206 | int group_no; | |
1207 | int goal_group; | |
1208 | ext2_grpblk_t grp_target_blk; /* blockgroup relative goal block */ | |
1209 | ext2_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ | |
1210 | ext2_fsblk_t ret_block; /* filesyetem-wide allocated block */ | |
1211 | int bgi; /* blockgroup iteration index */ | |
1212 | int performed_allocation = 0; | |
1213 | ext2_grpblk_t free_blocks; /* number of free blocks in a group */ | |
1214 | struct super_block *sb; | |
1215 | struct ext2_group_desc *gdp; | |
1216 | struct ext2_super_block *es; | |
1217 | struct ext2_sb_info *sbi; | |
1218 | struct ext2_reserve_window_node *my_rsv = NULL; | |
1219 | struct ext2_block_alloc_info *block_i; | |
1220 | unsigned short windowsz = 0; | |
1221 | unsigned long ngroups; | |
1222 | unsigned long num = *count; | |
5dd4056d | 1223 | int ret; |
a686cd89 MB |
1224 | |
1225 | *errp = -ENOSPC; | |
1226 | sb = inode->i_sb; | |
1da177e4 | 1227 | |
a686cd89 MB |
1228 | /* |
1229 | * Check quota for allocation of this block. | |
1230 | */ | |
5dd4056d CH |
1231 | ret = dquot_alloc_block(inode, num); |
1232 | if (ret) { | |
1233 | *errp = ret; | |
a686cd89 MB |
1234 | return 0; |
1235 | } | |
1da177e4 | 1236 | |
a686cd89 MB |
1237 | sbi = EXT2_SB(sb); |
1238 | es = EXT2_SB(sb)->s_es; | |
1239 | ext2_debug("goal=%lu.\n", goal); | |
1240 | /* | |
83f99de1 YB |
1241 | * Allocate a block from reservation only when the filesystem is |
1242 | * mounted with reservation(default,-o reservation), and it's a regular | |
1243 | * file, and the desired window size is greater than 0 (One could use | |
1244 | * ioctl command EXT2_IOC_SETRSVSZ to set the window size to 0 to turn | |
1245 | * off reservation on that particular file). Also do not use the | |
1246 | * reservation window if the caller asked us not to do it. | |
a686cd89 MB |
1247 | */ |
1248 | block_i = EXT2_I(inode)->i_block_alloc_info; | |
83f99de1 | 1249 | if (!(flags & EXT2_ALLOC_NORESERVE) && block_i) { |
a686cd89 MB |
1250 | windowsz = block_i->rsv_window_node.rsv_goal_size; |
1251 | if (windowsz > 0) | |
1252 | my_rsv = &block_i->rsv_window_node; | |
1da177e4 LT |
1253 | } |
1254 | ||
a686cd89 MB |
1255 | if (!ext2_has_free_blocks(sbi)) { |
1256 | *errp = -ENOSPC; | |
1257 | goto out; | |
1258 | } | |
1da177e4 | 1259 | |
a686cd89 MB |
1260 | /* |
1261 | * First, test whether the goal block is free. | |
1262 | */ | |
1da177e4 LT |
1263 | if (goal < le32_to_cpu(es->s_first_data_block) || |
1264 | goal >= le32_to_cpu(es->s_blocks_count)) | |
1265 | goal = le32_to_cpu(es->s_first_data_block); | |
a686cd89 MB |
1266 | group_no = (goal - le32_to_cpu(es->s_first_data_block)) / |
1267 | EXT2_BLOCKS_PER_GROUP(sb); | |
1268 | goal_group = group_no; | |
1269 | retry_alloc: | |
1270 | gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); | |
1271 | if (!gdp) | |
1da177e4 | 1272 | goto io_error; |
1da177e4 | 1273 | |
a686cd89 MB |
1274 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
1275 | /* | |
1276 | * if there is not enough free blocks to make a new resevation | |
1277 | * turn off reservation for this allocation | |
1278 | */ | |
1279 | if (my_rsv && (free_blocks < windowsz) | |
d707d31c | 1280 | && (free_blocks > 0) |
a686cd89 MB |
1281 | && (rsv_is_empty(&my_rsv->rsv_window))) |
1282 | my_rsv = NULL; | |
1283 | ||
1284 | if (free_blocks > 0) { | |
1285 | grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) % | |
1286 | EXT2_BLOCKS_PER_GROUP(sb)); | |
ba1af2e4 CX |
1287 | /* |
1288 | * In case we retry allocation (due to fs reservation not | |
1289 | * working out or fs corruption), the bitmap_bh is non-null | |
1290 | * pointer and we have to release it before calling | |
1291 | * read_block_bitmap(). | |
1292 | */ | |
1293 | brelse(bitmap_bh); | |
1da177e4 LT |
1294 | bitmap_bh = read_block_bitmap(sb, group_no); |
1295 | if (!bitmap_bh) | |
1296 | goto io_error; | |
a686cd89 MB |
1297 | grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, |
1298 | bitmap_bh, grp_target_blk, | |
1299 | my_rsv, &num); | |
1300 | if (grp_alloc_blk >= 0) | |
1301 | goto allocated; | |
1da177e4 LT |
1302 | } |
1303 | ||
a686cd89 MB |
1304 | ngroups = EXT2_SB(sb)->s_groups_count; |
1305 | smp_rmb(); | |
1da177e4 LT |
1306 | |
1307 | /* | |
144704e5 AM |
1308 | * Now search the rest of the groups. We assume that |
1309 | * group_no and gdp correctly point to the last group visited. | |
1da177e4 | 1310 | */ |
a686cd89 | 1311 | for (bgi = 0; bgi < ngroups; bgi++) { |
1da177e4 | 1312 | group_no++; |
a686cd89 | 1313 | if (group_no >= ngroups) |
1da177e4 | 1314 | group_no = 0; |
a686cd89 MB |
1315 | gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); |
1316 | if (!gdp) | |
1da177e4 | 1317 | goto io_error; |
1da177e4 | 1318 | |
a686cd89 | 1319 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
46891532 JK |
1320 | /* |
1321 | * skip this group (and avoid loading bitmap) if there | |
1322 | * are no free blocks | |
1323 | */ | |
1324 | if (!free_blocks) | |
1325 | continue; | |
1da177e4 | 1326 | /* |
a686cd89 MB |
1327 | * skip this group if the number of |
1328 | * free blocks is less than half of the reservation | |
1329 | * window size. | |
1da177e4 | 1330 | */ |
d707d31c | 1331 | if (my_rsv && (free_blocks <= (windowsz/2))) |
a686cd89 MB |
1332 | continue; |
1333 | ||
1334 | brelse(bitmap_bh); | |
1335 | bitmap_bh = read_block_bitmap(sb, group_no); | |
1336 | if (!bitmap_bh) | |
1da177e4 | 1337 | goto io_error; |
1da177e4 | 1338 | /* |
a686cd89 | 1339 | * try to allocate block(s) from this group, without a goal(-1). |
1da177e4 | 1340 | */ |
a686cd89 MB |
1341 | grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, |
1342 | bitmap_bh, -1, my_rsv, &num); | |
1343 | if (grp_alloc_blk >= 0) | |
1344 | goto allocated; | |
1345 | } | |
1346 | /* | |
25985edc | 1347 | * We may end up a bogus earlier ENOSPC error due to |
a686cd89 | 1348 | * filesystem is "full" of reservations, but |
25985edc | 1349 | * there maybe indeed free blocks available on disk |
a686cd89 MB |
1350 | * In this case, we just forget about the reservations |
1351 | * just do block allocation as without reservations. | |
1352 | */ | |
1353 | if (my_rsv) { | |
1354 | my_rsv = NULL; | |
1355 | windowsz = 0; | |
1356 | group_no = goal_group; | |
1357 | goto retry_alloc; | |
1da177e4 | 1358 | } |
a686cd89 MB |
1359 | /* No space left on the device */ |
1360 | *errp = -ENOSPC; | |
1361 | goto out; | |
1362 | ||
1363 | allocated: | |
1da177e4 | 1364 | |
1da177e4 | 1365 | ext2_debug("using block group %d(%d)\n", |
a686cd89 | 1366 | group_no, gdp->bg_free_blocks_count); |
1da177e4 | 1367 | |
a686cd89 | 1368 | ret_block = grp_alloc_blk + ext2_group_first_block_no(sb, group_no); |
1da177e4 | 1369 | |
a686cd89 MB |
1370 | if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) || |
1371 | in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) || | |
1372 | in_range(ret_block, le32_to_cpu(gdp->bg_inode_table), | |
1373 | EXT2_SB(sb)->s_itb_per_group) || | |
1374 | in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table), | |
7f0adaec | 1375 | EXT2_SB(sb)->s_itb_per_group)) { |
a686cd89 | 1376 | ext2_error(sb, "ext2_new_blocks", |
1da177e4 | 1377 | "Allocating block in system zone - " |
a686cd89 MB |
1378 | "blocks from "E2FSBLK", length %lu", |
1379 | ret_block, num); | |
8b915825 AK |
1380 | /* |
1381 | * ext2_try_to_allocate marked the blocks we allocated as in | |
1382 | * use. So we may want to selectively mark some of the blocks | |
1383 | * as free | |
1384 | */ | |
158be76c | 1385 | num = *count; |
8b915825 | 1386 | goto retry_alloc; |
7f0adaec | 1387 | } |
a686cd89 MB |
1388 | |
1389 | performed_allocation = 1; | |
1da177e4 | 1390 | |
a686cd89 MB |
1391 | if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) { |
1392 | ext2_error(sb, "ext2_new_blocks", | |
1393 | "block("E2FSBLK") >= blocks count(%d) - " | |
1da177e4 LT |
1394 | "block_group = %d, es == %p ", ret_block, |
1395 | le32_to_cpu(es->s_blocks_count), group_no, es); | |
a686cd89 | 1396 | goto out; |
1da177e4 | 1397 | } |
1da177e4 | 1398 | |
a686cd89 MB |
1399 | group_adjust_blocks(sb, group_no, gdp, gdp_bh, -num); |
1400 | percpu_counter_sub(&sbi->s_freeblocks_counter, num); | |
1da177e4 LT |
1401 | |
1402 | mark_buffer_dirty(bitmap_bh); | |
1751e8a6 | 1403 | if (sb->s_flags & SB_SYNCHRONOUS) |
1da177e4 LT |
1404 | sync_dirty_buffer(bitmap_bh); |
1405 | ||
a686cd89 MB |
1406 | *errp = 0; |
1407 | brelse(bitmap_bh); | |
8e3dffc6 WS |
1408 | if (num < *count) { |
1409 | dquot_free_block_nodirty(inode, *count-num); | |
1410 | mark_inode_dirty(inode); | |
1411 | *count = num; | |
1412 | } | |
a686cd89 | 1413 | return ret_block; |
1da177e4 | 1414 | |
a686cd89 MB |
1415 | io_error: |
1416 | *errp = -EIO; | |
1da177e4 | 1417 | out: |
a686cd89 MB |
1418 | /* |
1419 | * Undo the block allocation | |
1420 | */ | |
3889717d AV |
1421 | if (!performed_allocation) { |
1422 | dquot_free_block_nodirty(inode, *count); | |
1423 | mark_inode_dirty(inode); | |
1424 | } | |
1da177e4 | 1425 | brelse(bitmap_bh); |
a686cd89 MB |
1426 | return 0; |
1427 | } | |
1da177e4 | 1428 | |
21730eed VH |
1429 | #ifdef EXT2FS_DEBUG |
1430 | ||
ecd0afa3 | 1431 | unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars) |
21730eed | 1432 | { |
ecd0afa3 | 1433 | return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars); |
21730eed VH |
1434 | } |
1435 | ||
1436 | #endif /* EXT2FS_DEBUG */ | |
1437 | ||
1da177e4 LT |
1438 | unsigned long ext2_count_free_blocks (struct super_block * sb) |
1439 | { | |
1440 | struct ext2_group_desc * desc; | |
1441 | unsigned long desc_count = 0; | |
1442 | int i; | |
1443 | #ifdef EXT2FS_DEBUG | |
1444 | unsigned long bitmap_count, x; | |
1445 | struct ext2_super_block *es; | |
1446 | ||
1da177e4 LT |
1447 | es = EXT2_SB(sb)->s_es; |
1448 | desc_count = 0; | |
1449 | bitmap_count = 0; | |
1450 | desc = NULL; | |
1451 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { | |
1452 | struct buffer_head *bitmap_bh; | |
1453 | desc = ext2_get_group_desc (sb, i, NULL); | |
1454 | if (!desc) | |
1455 | continue; | |
1456 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); | |
1457 | bitmap_bh = read_block_bitmap(sb, i); | |
1458 | if (!bitmap_bh) | |
1459 | continue; | |
1460 | ||
1461 | x = ext2_count_free(bitmap_bh, sb->s_blocksize); | |
1462 | printk ("group %d: stored = %d, counted = %lu\n", | |
1463 | i, le16_to_cpu(desc->bg_free_blocks_count), x); | |
1464 | bitmap_count += x; | |
1465 | brelse(bitmap_bh); | |
1466 | } | |
1467 | printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n", | |
1468 | (long)le32_to_cpu(es->s_free_blocks_count), | |
1469 | desc_count, bitmap_count); | |
1da177e4 LT |
1470 | return bitmap_count; |
1471 | #else | |
b41b98e1 RT |
1472 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { |
1473 | desc = ext2_get_group_desc(sb, i, NULL); | |
1474 | if (!desc) | |
1475 | continue; | |
1476 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); | |
1da177e4 LT |
1477 | } |
1478 | return desc_count; | |
1479 | #endif | |
1480 | } | |
1481 | ||
1da177e4 LT |
1482 | static inline int test_root(int a, int b) |
1483 | { | |
1484 | int num = b; | |
1485 | ||
1486 | while (a > num) | |
1487 | num *= b; | |
1488 | return num == a; | |
1489 | } | |
1490 | ||
1491 | static int ext2_group_sparse(int group) | |
1492 | { | |
1493 | if (group <= 1) | |
1494 | return 1; | |
1495 | return (test_root(group, 3) || test_root(group, 5) || | |
1496 | test_root(group, 7)); | |
1497 | } | |
1498 | ||
1499 | /** | |
1500 | * ext2_bg_has_super - number of blocks used by the superblock in group | |
1501 | * @sb: superblock for filesystem | |
1502 | * @group: group number to check | |
1503 | * | |
1504 | * Return the number of blocks used by the superblock (primary or backup) | |
1505 | * in this group. Currently this will be only 0 or 1. | |
1506 | */ | |
1507 | int ext2_bg_has_super(struct super_block *sb, int group) | |
1508 | { | |
1509 | if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& | |
1510 | !ext2_group_sparse(group)) | |
1511 | return 0; | |
1512 | return 1; | |
1513 | } | |
1514 | ||
1515 | /** | |
1516 | * ext2_bg_num_gdb - number of blocks used by the group table in group | |
1517 | * @sb: superblock for filesystem | |
1518 | * @group: group number to check | |
1519 | * | |
1520 | * Return the number of blocks used by the group descriptor table | |
1521 | * (primary or backup) in this group. In the future there may be a | |
1522 | * different number of descriptor blocks in each group. | |
1523 | */ | |
1524 | unsigned long ext2_bg_num_gdb(struct super_block *sb, int group) | |
1525 | { | |
859cb936 | 1526 | return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0; |
1da177e4 LT |
1527 | } |
1528 |