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a60be987 RK |
1 | /* |
2 | * btnode.c - NILFS B-tree node cache | |
3 | * | |
4 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | * | |
20 | * This file was originally written by Seiji Kihara <kihara@osrg.net> | |
21 | * and fully revised by Ryusuke Konishi <ryusuke@osrg.net> for | |
22 | * stabilization and simplification. | |
23 | * | |
24 | */ | |
25 | ||
26 | #include <linux/types.h> | |
27 | #include <linux/buffer_head.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/backing-dev.h> | |
5a0e3ad6 | 30 | #include <linux/gfp.h> |
a60be987 RK |
31 | #include "nilfs.h" |
32 | #include "mdt.h" | |
33 | #include "dat.h" | |
34 | #include "page.h" | |
35 | #include "btnode.h" | |
36 | ||
37 | ||
38 | void nilfs_btnode_cache_init_once(struct address_space *btnc) | |
39 | { | |
ebdfed4d | 40 | nilfs_mapping_init_once(btnc); |
a60be987 RK |
41 | } |
42 | ||
a53b4751 RK |
43 | void nilfs_btnode_cache_init(struct address_space *btnc, |
44 | struct backing_dev_info *bdi) | |
a60be987 | 45 | { |
7eaceacc | 46 | nilfs_mapping_init(btnc, bdi); |
a60be987 RK |
47 | } |
48 | ||
49 | void nilfs_btnode_cache_clear(struct address_space *btnc) | |
50 | { | |
51 | invalidate_mapping_pages(btnc, 0, -1); | |
52 | truncate_inode_pages(btnc, 0); | |
53 | } | |
54 | ||
d501d736 RK |
55 | struct buffer_head * |
56 | nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) | |
57 | { | |
58 | struct inode *inode = NILFS_BTNC_I(btnc); | |
59 | struct buffer_head *bh; | |
60 | ||
61 | bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node); | |
62 | if (unlikely(!bh)) | |
63 | return NULL; | |
64 | ||
65 | if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || | |
66 | buffer_dirty(bh))) { | |
67 | brelse(bh); | |
68 | BUG(); | |
69 | } | |
70 | memset(bh->b_data, 0, 1 << inode->i_blkbits); | |
71 | bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; | |
72 | bh->b_blocknr = blocknr; | |
73 | set_buffer_mapped(bh); | |
74 | set_buffer_uptodate(bh); | |
75 | ||
76 | unlock_page(bh->b_page); | |
77 | page_cache_release(bh->b_page); | |
78 | return bh; | |
79 | } | |
80 | ||
a60be987 | 81 | int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, |
26dfdd8e RK |
82 | sector_t pblocknr, int mode, |
83 | struct buffer_head **pbh, sector_t *submit_ptr) | |
a60be987 RK |
84 | { |
85 | struct buffer_head *bh; | |
86 | struct inode *inode = NILFS_BTNC_I(btnc); | |
f8e6cc01 | 87 | struct page *page; |
a60be987 RK |
88 | int err; |
89 | ||
90 | bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node); | |
91 | if (unlikely(!bh)) | |
92 | return -ENOMEM; | |
93 | ||
94 | err = -EEXIST; /* internal code */ | |
f8e6cc01 | 95 | page = bh->b_page; |
a60be987 RK |
96 | |
97 | if (buffer_uptodate(bh) || buffer_dirty(bh)) | |
98 | goto found; | |
99 | ||
100 | if (pblocknr == 0) { | |
101 | pblocknr = blocknr; | |
102 | if (inode->i_ino != NILFS_DAT_INO) { | |
365e215c | 103 | struct inode *dat = NILFS_I_NILFS(inode)->ns_dat; |
a60be987 RK |
104 | |
105 | /* blocknr is a virtual block number */ | |
106 | err = nilfs_dat_translate(dat, blocknr, &pblocknr); | |
107 | if (unlikely(err)) { | |
108 | brelse(bh); | |
109 | goto out_locked; | |
110 | } | |
111 | } | |
112 | } | |
26dfdd8e RK |
113 | |
114 | if (mode == READA) { | |
115 | if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) { | |
116 | err = -EBUSY; /* internal code */ | |
117 | brelse(bh); | |
118 | goto out_locked; | |
119 | } | |
120 | } else { /* mode == READ */ | |
121 | lock_buffer(bh); | |
122 | } | |
a60be987 RK |
123 | if (buffer_uptodate(bh)) { |
124 | unlock_buffer(bh); | |
125 | err = -EEXIST; /* internal code */ | |
126 | goto found; | |
127 | } | |
128 | set_buffer_mapped(bh); | |
129 | bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; | |
130 | bh->b_blocknr = pblocknr; /* set block address for read */ | |
131 | bh->b_end_io = end_buffer_read_sync; | |
132 | get_bh(bh); | |
26dfdd8e | 133 | submit_bh(mode, bh); |
a60be987 | 134 | bh->b_blocknr = blocknr; /* set back to the given block address */ |
26dfdd8e | 135 | *submit_ptr = pblocknr; |
a60be987 RK |
136 | err = 0; |
137 | found: | |
138 | *pbh = bh; | |
139 | ||
140 | out_locked: | |
f8e6cc01 RK |
141 | unlock_page(page); |
142 | page_cache_release(page); | |
a60be987 RK |
143 | return err; |
144 | } | |
145 | ||
a60be987 RK |
146 | /** |
147 | * nilfs_btnode_delete - delete B-tree node buffer | |
148 | * @bh: buffer to be deleted | |
149 | * | |
150 | * nilfs_btnode_delete() invalidates the specified buffer and delete the page | |
151 | * including the buffer if the page gets unbusy. | |
152 | */ | |
153 | void nilfs_btnode_delete(struct buffer_head *bh) | |
154 | { | |
155 | struct address_space *mapping; | |
156 | struct page *page = bh->b_page; | |
157 | pgoff_t index = page_index(page); | |
158 | int still_dirty; | |
159 | ||
160 | page_cache_get(page); | |
161 | lock_page(page); | |
162 | wait_on_page_writeback(page); | |
163 | ||
164 | nilfs_forget_buffer(bh); | |
165 | still_dirty = PageDirty(page); | |
166 | mapping = page->mapping; | |
167 | unlock_page(page); | |
168 | page_cache_release(page); | |
169 | ||
170 | if (!still_dirty && mapping) | |
171 | invalidate_inode_pages2_range(mapping, index, index); | |
172 | } | |
173 | ||
174 | /** | |
175 | * nilfs_btnode_prepare_change_key | |
176 | * prepare to move contents of the block for old key to one of new key. | |
177 | * the old buffer will not be removed, but might be reused for new buffer. | |
178 | * it might return -ENOMEM because of memory allocation errors, | |
179 | * and might return -EIO because of disk read errors. | |
180 | */ | |
181 | int nilfs_btnode_prepare_change_key(struct address_space *btnc, | |
182 | struct nilfs_btnode_chkey_ctxt *ctxt) | |
183 | { | |
184 | struct buffer_head *obh, *nbh; | |
185 | struct inode *inode = NILFS_BTNC_I(btnc); | |
186 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; | |
187 | int err; | |
188 | ||
189 | if (oldkey == newkey) | |
190 | return 0; | |
191 | ||
192 | obh = ctxt->bh; | |
193 | ctxt->newbh = NULL; | |
194 | ||
195 | if (inode->i_blkbits == PAGE_CACHE_SHIFT) { | |
196 | lock_page(obh->b_page); | |
197 | /* | |
198 | * We cannot call radix_tree_preload for the kernels older | |
199 | * than 2.6.23, because it is not exported for modules. | |
200 | */ | |
b1f1b8ce | 201 | retry: |
a60be987 RK |
202 | err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); |
203 | if (err) | |
204 | goto failed_unlock; | |
205 | /* BUG_ON(oldkey != obh->b_page->index); */ | |
206 | if (unlikely(oldkey != obh->b_page->index)) | |
207 | NILFS_PAGE_BUG(obh->b_page, | |
208 | "invalid oldkey %lld (newkey=%lld)", | |
209 | (unsigned long long)oldkey, | |
210 | (unsigned long long)newkey); | |
211 | ||
a60be987 RK |
212 | spin_lock_irq(&btnc->tree_lock); |
213 | err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page); | |
214 | spin_unlock_irq(&btnc->tree_lock); | |
215 | /* | |
216 | * Note: page->index will not change to newkey until | |
217 | * nilfs_btnode_commit_change_key() will be called. | |
218 | * To protect the page in intermediate state, the page lock | |
219 | * is held. | |
220 | */ | |
221 | radix_tree_preload_end(); | |
222 | if (!err) | |
223 | return 0; | |
224 | else if (err != -EEXIST) | |
225 | goto failed_unlock; | |
226 | ||
227 | err = invalidate_inode_pages2_range(btnc, newkey, newkey); | |
228 | if (!err) | |
229 | goto retry; | |
230 | /* fallback to copy mode */ | |
231 | unlock_page(obh->b_page); | |
232 | } | |
233 | ||
45f4910b RK |
234 | nbh = nilfs_btnode_create_block(btnc, newkey); |
235 | if (!nbh) | |
236 | return -ENOMEM; | |
237 | ||
238 | BUG_ON(nbh == obh); | |
239 | ctxt->newbh = nbh; | |
240 | return 0; | |
a60be987 RK |
241 | |
242 | failed_unlock: | |
243 | unlock_page(obh->b_page); | |
244 | return err; | |
245 | } | |
246 | ||
247 | /** | |
248 | * nilfs_btnode_commit_change_key | |
249 | * commit the change_key operation prepared by prepare_change_key(). | |
250 | */ | |
251 | void nilfs_btnode_commit_change_key(struct address_space *btnc, | |
252 | struct nilfs_btnode_chkey_ctxt *ctxt) | |
253 | { | |
254 | struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh; | |
255 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; | |
256 | struct page *opage; | |
257 | ||
258 | if (oldkey == newkey) | |
259 | return; | |
260 | ||
261 | if (nbh == NULL) { /* blocksize == pagesize */ | |
262 | opage = obh->b_page; | |
263 | if (unlikely(oldkey != opage->index)) | |
264 | NILFS_PAGE_BUG(opage, | |
265 | "invalid oldkey %lld (newkey=%lld)", | |
266 | (unsigned long long)oldkey, | |
267 | (unsigned long long)newkey); | |
b1e19e56 | 268 | nilfs_btnode_mark_dirty(obh); |
a60be987 RK |
269 | |
270 | spin_lock_irq(&btnc->tree_lock); | |
271 | radix_tree_delete(&btnc->page_tree, oldkey); | |
272 | radix_tree_tag_set(&btnc->page_tree, newkey, | |
273 | PAGECACHE_TAG_DIRTY); | |
274 | spin_unlock_irq(&btnc->tree_lock); | |
275 | ||
276 | opage->index = obh->b_blocknr = newkey; | |
277 | unlock_page(opage); | |
278 | } else { | |
279 | nilfs_copy_buffer(nbh, obh); | |
280 | nilfs_btnode_mark_dirty(nbh); | |
281 | ||
282 | nbh->b_blocknr = newkey; | |
283 | ctxt->bh = nbh; | |
284 | nilfs_btnode_delete(obh); /* will decrement bh->b_count */ | |
285 | } | |
286 | } | |
287 | ||
288 | /** | |
289 | * nilfs_btnode_abort_change_key | |
290 | * abort the change_key operation prepared by prepare_change_key(). | |
291 | */ | |
292 | void nilfs_btnode_abort_change_key(struct address_space *btnc, | |
293 | struct nilfs_btnode_chkey_ctxt *ctxt) | |
294 | { | |
295 | struct buffer_head *nbh = ctxt->newbh; | |
296 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; | |
297 | ||
298 | if (oldkey == newkey) | |
299 | return; | |
300 | ||
301 | if (nbh == NULL) { /* blocksize == pagesize */ | |
302 | spin_lock_irq(&btnc->tree_lock); | |
303 | radix_tree_delete(&btnc->page_tree, newkey); | |
304 | spin_unlock_irq(&btnc->tree_lock); | |
305 | unlock_page(ctxt->bh->b_page); | |
306 | } else | |
307 | brelse(nbh); | |
308 | } |