vmscan: fix shrinker callback bug in fs/super.c
[linux-2.6.git] / fs / nilfs2 / direct.c
1 /*
2  * direct.c - NILFS direct block pointer.
3  *
4  * Copyright (C) 2006-2008 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  * Written by Koji Sato <koji@osrg.net>.
21  */
22
23 #include <linux/errno.h>
24 #include "nilfs.h"
25 #include "page.h"
26 #include "direct.h"
27 #include "alloc.h"
28 #include "dat.h"
29
30 static inline __le64 *nilfs_direct_dptrs(const struct nilfs_bmap *direct)
31 {
32         return (__le64 *)
33                 ((struct nilfs_direct_node *)direct->b_u.u_data + 1);
34 }
35
36 static inline __u64
37 nilfs_direct_get_ptr(const struct nilfs_bmap *direct, __u64 key)
38 {
39         return le64_to_cpu(*(nilfs_direct_dptrs(direct) + key));
40 }
41
42 static inline void nilfs_direct_set_ptr(struct nilfs_bmap *direct,
43                                         __u64 key, __u64 ptr)
44 {
45         *(nilfs_direct_dptrs(direct) + key) = cpu_to_le64(ptr);
46 }
47
48 static int nilfs_direct_lookup(const struct nilfs_bmap *direct,
49                                __u64 key, int level, __u64 *ptrp)
50 {
51         __u64 ptr;
52
53         if (key > NILFS_DIRECT_KEY_MAX || level != 1)
54                 return -ENOENT;
55         ptr = nilfs_direct_get_ptr(direct, key);
56         if (ptr == NILFS_BMAP_INVALID_PTR)
57                 return -ENOENT;
58
59         *ptrp = ptr;
60         return 0;
61 }
62
63 static int nilfs_direct_lookup_contig(const struct nilfs_bmap *direct,
64                                       __u64 key, __u64 *ptrp,
65                                       unsigned maxblocks)
66 {
67         struct inode *dat = NULL;
68         __u64 ptr, ptr2;
69         sector_t blocknr;
70         int ret, cnt;
71
72         if (key > NILFS_DIRECT_KEY_MAX)
73                 return -ENOENT;
74         ptr = nilfs_direct_get_ptr(direct, key);
75         if (ptr == NILFS_BMAP_INVALID_PTR)
76                 return -ENOENT;
77
78         if (NILFS_BMAP_USE_VBN(direct)) {
79                 dat = nilfs_bmap_get_dat(direct);
80                 ret = nilfs_dat_translate(dat, ptr, &blocknr);
81                 if (ret < 0)
82                         return ret;
83                 ptr = blocknr;
84         }
85
86         maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
87         for (cnt = 1; cnt < maxblocks &&
88                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
89                      NILFS_BMAP_INVALID_PTR;
90              cnt++) {
91                 if (dat) {
92                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
93                         if (ret < 0)
94                                 return ret;
95                         ptr2 = blocknr;
96                 }
97                 if (ptr2 != ptr + cnt)
98                         break;
99         }
100         *ptrp = ptr;
101         return cnt;
102 }
103
104 static __u64
105 nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
106 {
107         __u64 ptr;
108
109         ptr = nilfs_bmap_find_target_seq(direct, key);
110         if (ptr != NILFS_BMAP_INVALID_PTR)
111                 /* sequential access */
112                 return ptr;
113         else
114                 /* block group */
115                 return nilfs_bmap_find_target_in_group(direct);
116 }
117
118 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
119 {
120         union nilfs_bmap_ptr_req req;
121         struct inode *dat = NULL;
122         struct buffer_head *bh;
123         int ret;
124
125         if (key > NILFS_DIRECT_KEY_MAX)
126                 return -ENOENT;
127         if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
128                 return -EEXIST;
129
130         if (NILFS_BMAP_USE_VBN(bmap)) {
131                 req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
132                 dat = nilfs_bmap_get_dat(bmap);
133         }
134         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
135         if (!ret) {
136                 /* ptr must be a pointer to a buffer head. */
137                 bh = (struct buffer_head *)((unsigned long)ptr);
138                 set_buffer_nilfs_volatile(bh);
139
140                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
141                 nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
142
143                 if (!nilfs_bmap_dirty(bmap))
144                         nilfs_bmap_set_dirty(bmap);
145
146                 if (NILFS_BMAP_USE_VBN(bmap))
147                         nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
148
149                 nilfs_inode_add_blocks(bmap->b_inode, 1);
150         }
151         return ret;
152 }
153
154 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
155 {
156         union nilfs_bmap_ptr_req req;
157         struct inode *dat;
158         int ret;
159
160         if (key > NILFS_DIRECT_KEY_MAX ||
161             nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
162                 return -ENOENT;
163
164         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
165         req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
166
167         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
168         if (!ret) {
169                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
170                 nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
171                 nilfs_inode_sub_blocks(bmap->b_inode, 1);
172         }
173         return ret;
174 }
175
176 static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
177 {
178         __u64 key, lastkey;
179
180         lastkey = NILFS_DIRECT_KEY_MAX + 1;
181         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
182                 if (nilfs_direct_get_ptr(direct, key) !=
183                     NILFS_BMAP_INVALID_PTR)
184                         lastkey = key;
185
186         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
187                 return -ENOENT;
188
189         *keyp = lastkey;
190
191         return 0;
192 }
193
194 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
195 {
196         return key > NILFS_DIRECT_KEY_MAX;
197 }
198
199 static int nilfs_direct_gather_data(struct nilfs_bmap *direct,
200                                     __u64 *keys, __u64 *ptrs, int nitems)
201 {
202         __u64 key;
203         __u64 ptr;
204         int n;
205
206         if (nitems > NILFS_DIRECT_NBLOCKS)
207                 nitems = NILFS_DIRECT_NBLOCKS;
208         n = 0;
209         for (key = 0; key < nitems; key++) {
210                 ptr = nilfs_direct_get_ptr(direct, key);
211                 if (ptr != NILFS_BMAP_INVALID_PTR) {
212                         keys[n] = key;
213                         ptrs[n] = ptr;
214                         n++;
215                 }
216         }
217         return n;
218 }
219
220 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
221                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
222 {
223         __le64 *dptrs;
224         int ret, i, j;
225
226         /* no need to allocate any resource for conversion */
227
228         /* delete */
229         ret = bmap->b_ops->bop_delete(bmap, key);
230         if (ret < 0)
231                 return ret;
232
233         /* free resources */
234         if (bmap->b_ops->bop_clear != NULL)
235                 bmap->b_ops->bop_clear(bmap);
236
237         /* convert */
238         dptrs = nilfs_direct_dptrs(bmap);
239         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
240                 if ((j < n) && (i == keys[j])) {
241                         dptrs[i] = (i != key) ?
242                                 cpu_to_le64(ptrs[j]) :
243                                 NILFS_BMAP_INVALID_PTR;
244                         j++;
245                 } else
246                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
247         }
248
249         nilfs_direct_init(bmap);
250         return 0;
251 }
252
253 static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
254                                   struct buffer_head *bh)
255 {
256         struct nilfs_palloc_req oldreq, newreq;
257         struct inode *dat;
258         __u64 key;
259         __u64 ptr;
260         int ret;
261
262         if (!NILFS_BMAP_USE_VBN(bmap))
263                 return 0;
264
265         dat = nilfs_bmap_get_dat(bmap);
266         key = nilfs_bmap_data_get_key(bmap, bh);
267         ptr = nilfs_direct_get_ptr(bmap, key);
268         if (!buffer_nilfs_volatile(bh)) {
269                 oldreq.pr_entry_nr = ptr;
270                 newreq.pr_entry_nr = ptr;
271                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
272                 if (ret < 0)
273                         return ret;
274                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
275                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
276                 set_buffer_nilfs_volatile(bh);
277                 nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
278         } else
279                 ret = nilfs_dat_mark_dirty(dat, ptr);
280
281         return ret;
282 }
283
284 static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
285                                  __u64 key, __u64 ptr,
286                                  struct buffer_head **bh,
287                                  sector_t blocknr,
288                                  union nilfs_binfo *binfo)
289 {
290         struct inode *dat = nilfs_bmap_get_dat(direct);
291         union nilfs_bmap_ptr_req req;
292         int ret;
293
294         req.bpr_ptr = ptr;
295         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
296         if (!ret) {
297                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
298                 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
299                 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
300         }
301         return ret;
302 }
303
304 static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
305                                  __u64 key, __u64 ptr,
306                                  struct buffer_head **bh,
307                                  sector_t blocknr,
308                                  union nilfs_binfo *binfo)
309 {
310         nilfs_direct_set_ptr(direct, key, blocknr);
311
312         binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
313         binfo->bi_dat.bi_level = 0;
314
315         return 0;
316 }
317
318 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
319                                struct buffer_head **bh,
320                                sector_t blocknr,
321                                union nilfs_binfo *binfo)
322 {
323         __u64 key;
324         __u64 ptr;
325
326         key = nilfs_bmap_data_get_key(bmap, *bh);
327         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
328                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
329                        (unsigned long long)key);
330                 return -EINVAL;
331         }
332         ptr = nilfs_direct_get_ptr(bmap, key);
333         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
334                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
335                        (unsigned long long)ptr);
336                 return -EINVAL;
337         }
338
339         return NILFS_BMAP_USE_VBN(bmap) ?
340                 nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
341                 nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
342 }
343
344 static const struct nilfs_bmap_operations nilfs_direct_ops = {
345         .bop_lookup             =       nilfs_direct_lookup,
346         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
347         .bop_insert             =       nilfs_direct_insert,
348         .bop_delete             =       nilfs_direct_delete,
349         .bop_clear              =       NULL,
350
351         .bop_propagate          =       nilfs_direct_propagate,
352
353         .bop_lookup_dirty_buffers       =       NULL,
354
355         .bop_assign             =       nilfs_direct_assign,
356         .bop_mark               =       NULL,
357
358         .bop_last_key           =       nilfs_direct_last_key,
359         .bop_check_insert       =       nilfs_direct_check_insert,
360         .bop_check_delete       =       NULL,
361         .bop_gather_data        =       nilfs_direct_gather_data,
362 };
363
364
365 int nilfs_direct_init(struct nilfs_bmap *bmap)
366 {
367         bmap->b_ops = &nilfs_direct_ops;
368         return 0;
369 }