1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright |
4 | * details |
5 | */ |
6 | |
7 | #include <linux/time.h> |
8 | #include <linux/pagemap.h> |
9 | #include <linux/buffer_head.h> |
10 | #include "reiserfs.h" |
11 | |
12 | /* |
13 | * access to tail : when one is going to read tail it must make sure, that is |
14 | * not running. direct2indirect and indirect2direct can not run concurrently |
15 | */ |
16 | |
17 | /* |
18 | * Converts direct items to an unformatted node. Panics if file has no |
19 | * tail. -ENOSPC if no disk space for conversion |
20 | */ |
21 | /* |
22 | * path points to first direct item of the file regardless of how many of |
23 | * them are there |
24 | */ |
25 | int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, |
26 | struct treepath *path, struct buffer_head *unbh, |
27 | loff_t tail_offset) |
28 | { |
29 | struct super_block *sb = inode->i_sb; |
30 | struct buffer_head *up_to_date_bh; |
31 | struct item_head *p_le_ih = tp_item_head(path); |
32 | unsigned long total_tail = 0; |
33 | |
34 | /* Key to search for the last byte of the converted item. */ |
35 | struct cpu_key end_key; |
36 | |
37 | /* |
38 | * new indirect item to be inserted or key |
39 | * of unfm pointer to be pasted |
40 | */ |
41 | struct item_head ind_ih; |
42 | int blk_size; |
43 | /* returned value for reiserfs_insert_item and clones */ |
44 | int retval; |
45 | /* Handle on an unformatted node that will be inserted in the tree. */ |
46 | unp_t unfm_ptr; |
47 | |
48 | BUG_ON(!th->t_trans_id); |
49 | |
50 | REISERFS_SB(sb)->s_direct2indirect++; |
51 | |
52 | blk_size = sb->s_blocksize; |
53 | |
54 | /* |
55 | * and key to search for append or insert pointer to the new |
56 | * unformatted node. |
57 | */ |
58 | copy_item_head(to: &ind_ih, from: p_le_ih); |
59 | set_le_ih_k_offset(ih: &ind_ih, offset: tail_offset); |
60 | set_le_ih_k_type(ih: &ind_ih, TYPE_INDIRECT); |
61 | |
62 | /* Set the key to search for the place for new unfm pointer */ |
63 | make_cpu_key(cpu_key: &end_key, inode, offset: tail_offset, TYPE_INDIRECT, key_length: 4); |
64 | |
65 | /* FIXME: we could avoid this */ |
66 | if (search_for_position_by_key(sb, cpu_key: &end_key, search_path: path) == POSITION_FOUND) { |
67 | reiserfs_error(sb, "PAP-14030" , |
68 | "pasted or inserted byte exists in " |
69 | "the tree %K. Use fsck to repair." , &end_key); |
70 | pathrelse(search_path: path); |
71 | return -EIO; |
72 | } |
73 | |
74 | p_le_ih = tp_item_head(path); |
75 | |
76 | unfm_ptr = cpu_to_le32(unbh->b_blocknr); |
77 | |
78 | if (is_statdata_le_ih(ih: p_le_ih)) { |
79 | /* Insert new indirect item. */ |
80 | set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ |
81 | put_ih_item_len(&ind_ih, UNFM_P_SIZE); |
82 | PATH_LAST_POSITION(path)++; |
83 | retval = |
84 | reiserfs_insert_item(th, path, key: &end_key, ih: &ind_ih, inode, |
85 | body: (char *)&unfm_ptr); |
86 | } else { |
87 | /* Paste into last indirect item of an object. */ |
88 | retval = reiserfs_paste_into_item(th, path, key: &end_key, inode, |
89 | body: (char *)&unfm_ptr, |
90 | UNFM_P_SIZE); |
91 | } |
92 | if (retval) { |
93 | return retval; |
94 | } |
95 | /* |
96 | * note: from here there are two keys which have matching first |
97 | * three key components. They only differ by the fourth one. |
98 | */ |
99 | |
100 | /* Set the key to search for the direct items of the file */ |
101 | make_cpu_key(cpu_key: &end_key, inode, offset: max_reiserfs_offset(inode), TYPE_DIRECT, |
102 | key_length: 4); |
103 | |
104 | /* |
105 | * Move bytes from the direct items to the new unformatted node |
106 | * and delete them. |
107 | */ |
108 | while (1) { |
109 | int tail_size; |
110 | |
111 | /* |
112 | * end_key.k_offset is set so, that we will always have found |
113 | * last item of the file |
114 | */ |
115 | if (search_for_position_by_key(sb, cpu_key: &end_key, search_path: path) == |
116 | POSITION_FOUND) |
117 | reiserfs_panic(sb, "PAP-14050" , |
118 | "direct item (%K) not found" , &end_key); |
119 | p_le_ih = tp_item_head(path); |
120 | RFALSE(!is_direct_le_ih(p_le_ih), |
121 | "vs-14055: direct item expected(%K), found %h" , |
122 | &end_key, p_le_ih); |
123 | tail_size = (le_ih_k_offset(ih: p_le_ih) & (blk_size - 1)) |
124 | + ih_item_len(p_le_ih) - 1; |
125 | |
126 | /* |
127 | * we only send the unbh pointer if the buffer is not |
128 | * up to date. this avoids overwriting good data from |
129 | * writepage() with old data from the disk or buffer cache |
130 | * Special case: unbh->b_page will be NULL if we are coming |
131 | * through DIRECT_IO handler here. |
132 | */ |
133 | if (!unbh->b_page || buffer_uptodate(bh: unbh) |
134 | || PageUptodate(page: unbh->b_page)) { |
135 | up_to_date_bh = NULL; |
136 | } else { |
137 | up_to_date_bh = unbh; |
138 | } |
139 | retval = reiserfs_delete_item(th, path, key: &end_key, inode, |
140 | un_bh: up_to_date_bh); |
141 | |
142 | total_tail += retval; |
143 | |
144 | /* done: file does not have direct items anymore */ |
145 | if (tail_size == retval) |
146 | break; |
147 | |
148 | } |
149 | /* |
150 | * if we've copied bytes from disk into the page, we need to zero |
151 | * out the unused part of the block (it was not up to date before) |
152 | */ |
153 | if (up_to_date_bh) { |
154 | unsigned pgoff = |
155 | (tail_offset + total_tail - 1) & (PAGE_SIZE - 1); |
156 | char *kaddr = kmap_atomic(page: up_to_date_bh->b_page); |
157 | memset(kaddr + pgoff, 0, blk_size - total_tail); |
158 | kunmap_atomic(kaddr); |
159 | } |
160 | |
161 | REISERFS_I(inode)->i_first_direct_byte = U32_MAX; |
162 | |
163 | return 0; |
164 | } |
165 | |
166 | /* stolen from fs/buffer.c */ |
167 | void reiserfs_unmap_buffer(struct buffer_head *bh) |
168 | { |
169 | lock_buffer(bh); |
170 | if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { |
171 | BUG(); |
172 | } |
173 | clear_buffer_dirty(bh); |
174 | /* |
175 | * Remove the buffer from whatever list it belongs to. We are mostly |
176 | * interested in removing it from per-sb j_dirty_buffers list, to avoid |
177 | * BUG() on attempt to write not mapped buffer |
178 | */ |
179 | if ((!list_empty(head: &bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { |
180 | struct inode *inode = bh->b_folio->mapping->host; |
181 | struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); |
182 | spin_lock(lock: &j->j_dirty_buffers_lock); |
183 | list_del_init(entry: &bh->b_assoc_buffers); |
184 | reiserfs_free_jh(bh); |
185 | spin_unlock(lock: &j->j_dirty_buffers_lock); |
186 | } |
187 | clear_buffer_mapped(bh); |
188 | clear_buffer_req(bh); |
189 | clear_buffer_new(bh); |
190 | bh->b_bdev = NULL; |
191 | unlock_buffer(bh); |
192 | } |
193 | |
194 | /* |
195 | * this first locks inode (neither reads nor sync are permitted), |
196 | * reads tail through page cache, insert direct item. When direct item |
197 | * inserted successfully inode is left locked. Return value is always |
198 | * what we expect from it (number of cut bytes). But when tail remains |
199 | * in the unformatted node, we set mode to SKIP_BALANCING and unlock |
200 | * inode |
201 | */ |
202 | int indirect2direct(struct reiserfs_transaction_handle *th, |
203 | struct inode *inode, struct page *page, |
204 | struct treepath *path, /* path to the indirect item. */ |
205 | const struct cpu_key *item_key, /* Key to look for |
206 | * unformatted node |
207 | * pointer to be cut. */ |
208 | loff_t n_new_file_size, /* New file size. */ |
209 | char *mode) |
210 | { |
211 | struct super_block *sb = inode->i_sb; |
212 | struct item_head s_ih; |
213 | unsigned long block_size = sb->s_blocksize; |
214 | char *tail; |
215 | int tail_len, round_tail_len; |
216 | loff_t pos, pos1; /* position of first byte of the tail */ |
217 | struct cpu_key key; |
218 | |
219 | BUG_ON(!th->t_trans_id); |
220 | |
221 | REISERFS_SB(sb)->s_indirect2direct++; |
222 | |
223 | *mode = M_SKIP_BALANCING; |
224 | |
225 | /* store item head path points to. */ |
226 | copy_item_head(to: &s_ih, from: tp_item_head(path)); |
227 | |
228 | tail_len = (n_new_file_size & (block_size - 1)); |
229 | if (get_inode_sd_version(inode) == STAT_DATA_V2) |
230 | round_tail_len = ROUND_UP(tail_len); |
231 | else |
232 | round_tail_len = tail_len; |
233 | |
234 | pos = |
235 | le_ih_k_offset(ih: &s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - |
236 | 1) * sb->s_blocksize; |
237 | pos1 = pos; |
238 | |
239 | /* |
240 | * we are protected by i_mutex. The tail can not disapper, not |
241 | * append can be done either |
242 | * we are in truncate or packing tail in file_release |
243 | */ |
244 | |
245 | tail = (char *)kmap(page); /* this can schedule */ |
246 | |
247 | if (path_changed(&s_ih, path)) { |
248 | /* re-search indirect item */ |
249 | if (search_for_position_by_key(sb, cpu_key: item_key, search_path: path) |
250 | == POSITION_NOT_FOUND) |
251 | reiserfs_panic(sb, "PAP-5520" , |
252 | "item to be converted %K does not exist" , |
253 | item_key); |
254 | copy_item_head(to: &s_ih, from: tp_item_head(path)); |
255 | #ifdef CONFIG_REISERFS_CHECK |
256 | pos = le_ih_k_offset(ih: &s_ih) - 1 + |
257 | (ih_item_len(&s_ih) / UNFM_P_SIZE - |
258 | 1) * sb->s_blocksize; |
259 | if (pos != pos1) |
260 | reiserfs_panic(sb, "vs-5530" , "tail position " |
261 | "changed while we were reading it" ); |
262 | #endif |
263 | } |
264 | |
265 | /* Set direct item header to insert. */ |
266 | make_le_item_head(ih: &s_ih, NULL, get_inode_item_key_version(inode), |
267 | offset: pos1 + 1, TYPE_DIRECT, length: round_tail_len, |
268 | entry_count: 0xffff /*ih_free_space */ ); |
269 | |
270 | /* |
271 | * we want a pointer to the first byte of the tail in the page. |
272 | * the page was locked and this part of the page was up to date when |
273 | * indirect2direct was called, so we know the bytes are still valid |
274 | */ |
275 | tail = tail + (pos & (PAGE_SIZE - 1)); |
276 | |
277 | PATH_LAST_POSITION(path)++; |
278 | |
279 | key = *item_key; |
280 | set_cpu_key_k_type(key: &key, TYPE_DIRECT); |
281 | key.key_length = 4; |
282 | /* Insert tail as new direct item in the tree */ |
283 | if (reiserfs_insert_item(th, path, key: &key, ih: &s_ih, inode, |
284 | body: tail ? tail : NULL) < 0) { |
285 | /* |
286 | * No disk memory. So we can not convert last unformatted node |
287 | * to the direct item. In this case we used to adjust |
288 | * indirect items's ih_free_space. Now ih_free_space is not |
289 | * used, it would be ideal to write zeros to corresponding |
290 | * unformatted node. For now i_size is considered as guard for |
291 | * going out of file size |
292 | */ |
293 | kunmap(page); |
294 | return block_size - round_tail_len; |
295 | } |
296 | kunmap(page); |
297 | |
298 | /* make sure to get the i_blocks changes from reiserfs_insert_item */ |
299 | reiserfs_update_sd(th, inode); |
300 | |
301 | /* |
302 | * note: we have now the same as in above direct2indirect |
303 | * conversion: there are two keys which have matching first three |
304 | * key components. They only differ by the fourth one. |
305 | */ |
306 | |
307 | /* |
308 | * We have inserted new direct item and must remove last |
309 | * unformatted node. |
310 | */ |
311 | *mode = M_CUT; |
312 | |
313 | /* we store position of first direct item in the in-core inode */ |
314 | /* mark_file_with_tail (inode, pos1 + 1); */ |
315 | REISERFS_I(inode)->i_first_direct_byte = pos1 + 1; |
316 | |
317 | return block_size - round_tail_len; |
318 | } |
319 | |