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1da177e4 LT |
1 | /* |
2 | * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details | |
3 | */ | |
4 | ||
5 | #include <linux/config.h> | |
6 | #include <linux/time.h> | |
7 | #include <linux/pagemap.h> | |
8 | #include <linux/buffer_head.h> | |
9 | #include <linux/reiserfs_fs.h> | |
10 | ||
11 | /* access to tail : when one is going to read tail it must make sure, that is not running. | |
12 | direct2indirect and indirect2direct can not run concurrently */ | |
13 | ||
1da177e4 LT |
14 | /* Converts direct items to an unformatted node. Panics if file has no |
15 | tail. -ENOSPC if no disk space for conversion */ | |
16 | /* path points to first direct item of the file regarless of how many of | |
17 | them are there */ | |
bd4c625c LT |
18 | int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, |
19 | struct path *path, struct buffer_head *unbh, | |
20 | loff_t tail_offset) | |
1da177e4 | 21 | { |
bd4c625c LT |
22 | struct super_block *sb = inode->i_sb; |
23 | struct buffer_head *up_to_date_bh; | |
24 | struct item_head *p_le_ih = PATH_PITEM_HEAD(path); | |
25 | unsigned long total_tail = 0; | |
26 | struct cpu_key end_key; /* Key to search for the last byte of the | |
27 | converted item. */ | |
28 | struct item_head ind_ih; /* new indirect item to be inserted or | |
29 | key of unfm pointer to be pasted */ | |
30 | int n_blk_size, n_retval; /* returned value for reiserfs_insert_item and clones */ | |
31 | unp_t unfm_ptr; /* Handle on an unformatted node | |
32 | that will be inserted in the | |
33 | tree. */ | |
34 | ||
35 | BUG_ON(!th->t_trans_id); | |
36 | ||
37 | REISERFS_SB(sb)->s_direct2indirect++; | |
38 | ||
39 | n_blk_size = sb->s_blocksize; | |
40 | ||
41 | /* and key to search for append or insert pointer to the new | |
42 | unformatted node. */ | |
43 | copy_item_head(&ind_ih, p_le_ih); | |
44 | set_le_ih_k_offset(&ind_ih, tail_offset); | |
45 | set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); | |
46 | ||
47 | /* Set the key to search for the place for new unfm pointer */ | |
48 | make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); | |
49 | ||
50 | // FIXME: we could avoid this | |
51 | if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { | |
52 | reiserfs_warning(sb, "PAP-14030: direct2indirect: " | |
53 | "pasted or inserted byte exists in the tree %K. " | |
54 | "Use fsck to repair.", &end_key); | |
55 | pathrelse(path); | |
56 | return -EIO; | |
57 | } | |
58 | ||
59 | p_le_ih = PATH_PITEM_HEAD(path); | |
60 | ||
61 | unfm_ptr = cpu_to_le32(unbh->b_blocknr); | |
62 | ||
63 | if (is_statdata_le_ih(p_le_ih)) { | |
64 | /* Insert new indirect item. */ | |
65 | set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ | |
66 | put_ih_item_len(&ind_ih, UNFM_P_SIZE); | |
67 | PATH_LAST_POSITION(path)++; | |
68 | n_retval = | |
69 | reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, | |
1da177e4 | 70 | (char *)&unfm_ptr); |
1da177e4 | 71 | } else { |
bd4c625c LT |
72 | /* Paste into last indirect item of an object. */ |
73 | n_retval = reiserfs_paste_into_item(th, path, &end_key, inode, | |
74 | (char *)&unfm_ptr, | |
75 | UNFM_P_SIZE); | |
1da177e4 | 76 | } |
bd4c625c LT |
77 | if (n_retval) { |
78 | return n_retval; | |
79 | } | |
80 | // note: from here there are two keys which have matching first | |
81 | // three key components. They only differ by the fourth one. | |
82 | ||
83 | /* Set the key to search for the direct items of the file */ | |
84 | make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, | |
85 | 4); | |
86 | ||
87 | /* Move bytes from the direct items to the new unformatted node | |
88 | and delete them. */ | |
89 | while (1) { | |
90 | int tail_size; | |
91 | ||
92 | /* end_key.k_offset is set so, that we will always have found | |
93 | last item of the file */ | |
94 | if (search_for_position_by_key(sb, &end_key, path) == | |
95 | POSITION_FOUND) | |
96 | reiserfs_panic(sb, | |
97 | "PAP-14050: direct2indirect: " | |
98 | "direct item (%K) not found", &end_key); | |
99 | p_le_ih = PATH_PITEM_HEAD(path); | |
100 | RFALSE(!is_direct_le_ih(p_le_ih), | |
101 | "vs-14055: direct item expected(%K), found %h", | |
102 | &end_key, p_le_ih); | |
103 | tail_size = (le_ih_k_offset(p_le_ih) & (n_blk_size - 1)) | |
104 | + ih_item_len(p_le_ih) - 1; | |
105 | ||
106 | /* we only send the unbh pointer if the buffer is not up to date. | |
107 | ** this avoids overwriting good data from writepage() with old data | |
108 | ** from the disk or buffer cache | |
109 | ** Special case: unbh->b_page will be NULL if we are coming through | |
110 | ** DIRECT_IO handler here. | |
111 | */ | |
112 | if (!unbh->b_page || buffer_uptodate(unbh) | |
113 | || PageUptodate(unbh->b_page)) { | |
114 | up_to_date_bh = NULL; | |
115 | } else { | |
116 | up_to_date_bh = unbh; | |
117 | } | |
118 | n_retval = reiserfs_delete_item(th, path, &end_key, inode, | |
119 | up_to_date_bh); | |
120 | ||
121 | total_tail += n_retval; | |
122 | if (tail_size == n_retval) | |
123 | // done: file does not have direct items anymore | |
124 | break; | |
1da177e4 | 125 | |
bd4c625c LT |
126 | } |
127 | /* if we've copied bytes from disk into the page, we need to zero | |
128 | ** out the unused part of the block (it was not up to date before) | |
129 | */ | |
130 | if (up_to_date_bh) { | |
131 | unsigned pgoff = | |
132 | (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1); | |
133 | char *kaddr = kmap_atomic(up_to_date_bh->b_page, KM_USER0); | |
134 | memset(kaddr + pgoff, 0, n_blk_size - total_tail); | |
135 | kunmap_atomic(kaddr, KM_USER0); | |
136 | } | |
137 | ||
138 | REISERFS_I(inode)->i_first_direct_byte = U32_MAX; | |
139 | ||
140 | return 0; | |
141 | } | |
1da177e4 LT |
142 | |
143 | /* stolen from fs/buffer.c */ | |
bd4c625c LT |
144 | void reiserfs_unmap_buffer(struct buffer_head *bh) |
145 | { | |
146 | lock_buffer(bh); | |
147 | if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { | |
148 | BUG(); | |
149 | } | |
150 | clear_buffer_dirty(bh); | |
151 | /* Remove the buffer from whatever list it belongs to. We are mostly | |
152 | interested in removing it from per-sb j_dirty_buffers list, to avoid | |
153 | BUG() on attempt to write not mapped buffer */ | |
154 | if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { | |
155 | struct inode *inode = bh->b_page->mapping->host; | |
156 | struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); | |
157 | spin_lock(&j->j_dirty_buffers_lock); | |
158 | list_del_init(&bh->b_assoc_buffers); | |
159 | reiserfs_free_jh(bh); | |
160 | spin_unlock(&j->j_dirty_buffers_lock); | |
161 | } | |
162 | clear_buffer_mapped(bh); | |
163 | clear_buffer_req(bh); | |
164 | clear_buffer_new(bh); | |
165 | bh->b_bdev = NULL; | |
166 | unlock_buffer(bh); | |
1da177e4 LT |
167 | } |
168 | ||
169 | /* this first locks inode (neither reads nor sync are permitted), | |
170 | reads tail through page cache, insert direct item. When direct item | |
171 | inserted successfully inode is left locked. Return value is always | |
172 | what we expect from it (number of cut bytes). But when tail remains | |
173 | in the unformatted node, we set mode to SKIP_BALANCING and unlock | |
174 | inode */ | |
bd4c625c LT |
175 | int indirect2direct(struct reiserfs_transaction_handle *th, struct inode *p_s_inode, struct page *page, struct path *p_s_path, /* path to the indirect item. */ |
176 | const struct cpu_key *p_s_item_key, /* Key to look for unformatted node pointer to be cut. */ | |
177 | loff_t n_new_file_size, /* New file size. */ | |
178 | char *p_c_mode) | |
1da177e4 | 179 | { |
bd4c625c LT |
180 | struct super_block *p_s_sb = p_s_inode->i_sb; |
181 | struct item_head s_ih; | |
182 | unsigned long n_block_size = p_s_sb->s_blocksize; | |
183 | char *tail; | |
184 | int tail_len, round_tail_len; | |
185 | loff_t pos, pos1; /* position of first byte of the tail */ | |
186 | struct cpu_key key; | |
1da177e4 | 187 | |
bd4c625c | 188 | BUG_ON(!th->t_trans_id); |
1da177e4 | 189 | |
bd4c625c | 190 | REISERFS_SB(p_s_sb)->s_indirect2direct++; |
1da177e4 | 191 | |
bd4c625c | 192 | *p_c_mode = M_SKIP_BALANCING; |
1da177e4 | 193 | |
bd4c625c | 194 | /* store item head path points to. */ |
1da177e4 | 195 | copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); |
bd4c625c LT |
196 | |
197 | tail_len = (n_new_file_size & (n_block_size - 1)); | |
198 | if (get_inode_sd_version(p_s_inode) == STAT_DATA_V2) | |
199 | round_tail_len = ROUND_UP(tail_len); | |
200 | else | |
201 | round_tail_len = tail_len; | |
202 | ||
203 | pos = | |
204 | le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - | |
205 | 1) * p_s_sb->s_blocksize; | |
206 | pos1 = pos; | |
207 | ||
208 | // we are protected by i_sem. The tail can not disapper, not | |
209 | // append can be done either | |
210 | // we are in truncate or packing tail in file_release | |
211 | ||
212 | tail = (char *)kmap(page); /* this can schedule */ | |
213 | ||
214 | if (path_changed(&s_ih, p_s_path)) { | |
215 | /* re-search indirect item */ | |
216 | if (search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path) | |
217 | == POSITION_NOT_FOUND) | |
218 | reiserfs_panic(p_s_sb, | |
219 | "PAP-5520: indirect2direct: " | |
220 | "item to be converted %K does not exist", | |
221 | p_s_item_key); | |
222 | copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); | |
1da177e4 | 223 | #ifdef CONFIG_REISERFS_CHECK |
bd4c625c LT |
224 | pos = le_ih_k_offset(&s_ih) - 1 + |
225 | (ih_item_len(&s_ih) / UNFM_P_SIZE - | |
226 | 1) * p_s_sb->s_blocksize; | |
227 | if (pos != pos1) | |
228 | reiserfs_panic(p_s_sb, "vs-5530: indirect2direct: " | |
229 | "tail position changed while we were reading it"); | |
1da177e4 | 230 | #endif |
bd4c625c | 231 | } |
1da177e4 | 232 | |
bd4c625c LT |
233 | /* Set direct item header to insert. */ |
234 | make_le_item_head(&s_ih, NULL, get_inode_item_key_version(p_s_inode), | |
235 | pos1 + 1, TYPE_DIRECT, round_tail_len, | |
236 | 0xffff /*ih_free_space */ ); | |
237 | ||
238 | /* we want a pointer to the first byte of the tail in the page. | |
239 | ** the page was locked and this part of the page was up to date when | |
240 | ** indirect2direct was called, so we know the bytes are still valid | |
241 | */ | |
242 | tail = tail + (pos & (PAGE_CACHE_SIZE - 1)); | |
243 | ||
244 | PATH_LAST_POSITION(p_s_path)++; | |
245 | ||
246 | key = *p_s_item_key; | |
247 | set_cpu_key_k_type(&key, TYPE_DIRECT); | |
248 | key.key_length = 4; | |
249 | /* Insert tail as new direct item in the tree */ | |
250 | if (reiserfs_insert_item(th, p_s_path, &key, &s_ih, p_s_inode, | |
251 | tail ? tail : NULL) < 0) { | |
252 | /* No disk memory. So we can not convert last unformatted node | |
253 | to the direct item. In this case we used to adjust | |
254 | indirect items's ih_free_space. Now ih_free_space is not | |
255 | used, it would be ideal to write zeros to corresponding | |
256 | unformatted node. For now i_size is considered as guard for | |
257 | going out of file size */ | |
258 | kunmap(page); | |
259 | return n_block_size - round_tail_len; | |
260 | } | |
261 | kunmap(page); | |
1da177e4 | 262 | |
bd4c625c LT |
263 | /* make sure to get the i_blocks changes from reiserfs_insert_item */ |
264 | reiserfs_update_sd(th, p_s_inode); | |
1da177e4 | 265 | |
bd4c625c LT |
266 | // note: we have now the same as in above direct2indirect |
267 | // conversion: there are two keys which have matching first three | |
268 | // key components. They only differ by the fouhth one. | |
1da177e4 | 269 | |
bd4c625c LT |
270 | /* We have inserted new direct item and must remove last |
271 | unformatted node. */ | |
272 | *p_c_mode = M_CUT; | |
1da177e4 | 273 | |
bd4c625c LT |
274 | /* we store position of first direct item in the in-core inode */ |
275 | //mark_file_with_tail (p_s_inode, pos1 + 1); | |
276 | REISERFS_I(p_s_inode)->i_first_direct_byte = pos1 + 1; | |
1da177e4 | 277 | |
bd4c625c LT |
278 | return n_block_size - round_tail_len; |
279 | } |