GNU Linux-libre 4.9.308-gnu1
[releases.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  * Written by Koji Sato.
17  */
18
19 #include <linux/errno.h>
20 #include "nilfs.h"
21 #include "page.h"
22 #include "direct.h"
23 #include "alloc.h"
24 #include "dat.h"
25
26 static inline __le64 *nilfs_direct_dptrs(const struct nilfs_bmap *direct)
27 {
28         return (__le64 *)
29                 ((struct nilfs_direct_node *)direct->b_u.u_data + 1);
30 }
31
32 static inline __u64
33 nilfs_direct_get_ptr(const struct nilfs_bmap *direct, __u64 key)
34 {
35         return le64_to_cpu(*(nilfs_direct_dptrs(direct) + key));
36 }
37
38 static inline void nilfs_direct_set_ptr(struct nilfs_bmap *direct,
39                                         __u64 key, __u64 ptr)
40 {
41         *(nilfs_direct_dptrs(direct) + key) = cpu_to_le64(ptr);
42 }
43
44 static int nilfs_direct_lookup(const struct nilfs_bmap *direct,
45                                __u64 key, int level, __u64 *ptrp)
46 {
47         __u64 ptr;
48
49         if (key > NILFS_DIRECT_KEY_MAX || level != 1)
50                 return -ENOENT;
51         ptr = nilfs_direct_get_ptr(direct, key);
52         if (ptr == NILFS_BMAP_INVALID_PTR)
53                 return -ENOENT;
54
55         *ptrp = ptr;
56         return 0;
57 }
58
59 static int nilfs_direct_lookup_contig(const struct nilfs_bmap *direct,
60                                       __u64 key, __u64 *ptrp,
61                                       unsigned int maxblocks)
62 {
63         struct inode *dat = NULL;
64         __u64 ptr, ptr2;
65         sector_t blocknr;
66         int ret, cnt;
67
68         if (key > NILFS_DIRECT_KEY_MAX)
69                 return -ENOENT;
70         ptr = nilfs_direct_get_ptr(direct, key);
71         if (ptr == NILFS_BMAP_INVALID_PTR)
72                 return -ENOENT;
73
74         if (NILFS_BMAP_USE_VBN(direct)) {
75                 dat = nilfs_bmap_get_dat(direct);
76                 ret = nilfs_dat_translate(dat, ptr, &blocknr);
77                 if (ret < 0)
78                         return ret;
79                 ptr = blocknr;
80         }
81
82         maxblocks = min_t(unsigned int, maxblocks,
83                           NILFS_DIRECT_KEY_MAX - key + 1);
84         for (cnt = 1; cnt < maxblocks &&
85                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
86                      NILFS_BMAP_INVALID_PTR;
87              cnt++) {
88                 if (dat) {
89                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
90                         if (ret < 0)
91                                 return ret;
92                         ptr2 = blocknr;
93                 }
94                 if (ptr2 != ptr + cnt)
95                         break;
96         }
97         *ptrp = ptr;
98         return cnt;
99 }
100
101 static __u64
102 nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
103 {
104         __u64 ptr;
105
106         ptr = nilfs_bmap_find_target_seq(direct, key);
107         if (ptr != NILFS_BMAP_INVALID_PTR)
108                 /* sequential access */
109                 return ptr;
110
111         /* block group */
112         return nilfs_bmap_find_target_in_group(direct);
113 }
114
115 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
116 {
117         union nilfs_bmap_ptr_req req;
118         struct inode *dat = NULL;
119         struct buffer_head *bh;
120         int ret;
121
122         if (key > NILFS_DIRECT_KEY_MAX)
123                 return -ENOENT;
124         if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
125                 return -EEXIST;
126
127         if (NILFS_BMAP_USE_VBN(bmap)) {
128                 req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
129                 dat = nilfs_bmap_get_dat(bmap);
130         }
131         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
132         if (!ret) {
133                 /* ptr must be a pointer to a buffer head. */
134                 bh = (struct buffer_head *)((unsigned long)ptr);
135                 set_buffer_nilfs_volatile(bh);
136
137                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
138                 nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
139
140                 if (!nilfs_bmap_dirty(bmap))
141                         nilfs_bmap_set_dirty(bmap);
142
143                 if (NILFS_BMAP_USE_VBN(bmap))
144                         nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
145
146                 nilfs_inode_add_blocks(bmap->b_inode, 1);
147         }
148         return ret;
149 }
150
151 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
152 {
153         union nilfs_bmap_ptr_req req;
154         struct inode *dat;
155         int ret;
156
157         if (key > NILFS_DIRECT_KEY_MAX ||
158             nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
159                 return -ENOENT;
160
161         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
162         req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
163
164         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
165         if (!ret) {
166                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
167                 nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
168                 nilfs_inode_sub_blocks(bmap->b_inode, 1);
169         }
170         return ret;
171 }
172
173 static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,
174                                  __u64 *keyp)
175 {
176         __u64 key;
177
178         for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {
179                 if (nilfs_direct_get_ptr(direct, key) !=
180                     NILFS_BMAP_INVALID_PTR) {
181                         *keyp = key;
182                         return 0;
183                 }
184         }
185         return -ENOENT;
186 }
187
188 static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
189 {
190         __u64 key, lastkey;
191
192         lastkey = NILFS_DIRECT_KEY_MAX + 1;
193         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
194                 if (nilfs_direct_get_ptr(direct, key) !=
195                     NILFS_BMAP_INVALID_PTR)
196                         lastkey = key;
197
198         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
199                 return -ENOENT;
200
201         *keyp = lastkey;
202
203         return 0;
204 }
205
206 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
207 {
208         return key > NILFS_DIRECT_KEY_MAX;
209 }
210
211 static int nilfs_direct_gather_data(struct nilfs_bmap *direct,
212                                     __u64 *keys, __u64 *ptrs, int nitems)
213 {
214         __u64 key;
215         __u64 ptr;
216         int n;
217
218         if (nitems > NILFS_DIRECT_NBLOCKS)
219                 nitems = NILFS_DIRECT_NBLOCKS;
220         n = 0;
221         for (key = 0; key < nitems; key++) {
222                 ptr = nilfs_direct_get_ptr(direct, key);
223                 if (ptr != NILFS_BMAP_INVALID_PTR) {
224                         keys[n] = key;
225                         ptrs[n] = ptr;
226                         n++;
227                 }
228         }
229         return n;
230 }
231
232 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
233                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
234 {
235         __le64 *dptrs;
236         int ret, i, j;
237
238         /* no need to allocate any resource for conversion */
239
240         /* delete */
241         ret = bmap->b_ops->bop_delete(bmap, key);
242         if (ret < 0)
243                 return ret;
244
245         /* free resources */
246         if (bmap->b_ops->bop_clear != NULL)
247                 bmap->b_ops->bop_clear(bmap);
248
249         /* convert */
250         dptrs = nilfs_direct_dptrs(bmap);
251         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
252                 if ((j < n) && (i == keys[j])) {
253                         dptrs[i] = (i != key) ?
254                                 cpu_to_le64(ptrs[j]) :
255                                 NILFS_BMAP_INVALID_PTR;
256                         j++;
257                 } else
258                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
259         }
260
261         nilfs_direct_init(bmap);
262         return 0;
263 }
264
265 static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
266                                   struct buffer_head *bh)
267 {
268         struct nilfs_palloc_req oldreq, newreq;
269         struct inode *dat;
270         __u64 key;
271         __u64 ptr;
272         int ret;
273
274         if (!NILFS_BMAP_USE_VBN(bmap))
275                 return 0;
276
277         dat = nilfs_bmap_get_dat(bmap);
278         key = nilfs_bmap_data_get_key(bmap, bh);
279         ptr = nilfs_direct_get_ptr(bmap, key);
280         if (!buffer_nilfs_volatile(bh)) {
281                 oldreq.pr_entry_nr = ptr;
282                 newreq.pr_entry_nr = ptr;
283                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
284                 if (ret < 0)
285                         return ret;
286                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
287                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
288                 set_buffer_nilfs_volatile(bh);
289                 nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
290         } else
291                 ret = nilfs_dat_mark_dirty(dat, ptr);
292
293         return ret;
294 }
295
296 static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
297                                  __u64 key, __u64 ptr,
298                                  struct buffer_head **bh,
299                                  sector_t blocknr,
300                                  union nilfs_binfo *binfo)
301 {
302         struct inode *dat = nilfs_bmap_get_dat(direct);
303         union nilfs_bmap_ptr_req req;
304         int ret;
305
306         req.bpr_ptr = ptr;
307         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
308         if (!ret) {
309                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
310                 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
311                 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
312         }
313         return ret;
314 }
315
316 static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
317                                  __u64 key, __u64 ptr,
318                                  struct buffer_head **bh,
319                                  sector_t blocknr,
320                                  union nilfs_binfo *binfo)
321 {
322         nilfs_direct_set_ptr(direct, key, blocknr);
323
324         binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
325         binfo->bi_dat.bi_level = 0;
326
327         return 0;
328 }
329
330 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
331                                struct buffer_head **bh,
332                                sector_t blocknr,
333                                union nilfs_binfo *binfo)
334 {
335         __u64 key;
336         __u64 ptr;
337
338         key = nilfs_bmap_data_get_key(bmap, *bh);
339         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
340                 nilfs_msg(bmap->b_inode->i_sb, KERN_CRIT,
341                           "%s (ino=%lu): invalid key: %llu", __func__,
342                           bmap->b_inode->i_ino, (unsigned long long)key);
343                 return -EINVAL;
344         }
345         ptr = nilfs_direct_get_ptr(bmap, key);
346         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
347                 nilfs_msg(bmap->b_inode->i_sb, KERN_CRIT,
348                           "%s (ino=%lu): invalid pointer: %llu", __func__,
349                           bmap->b_inode->i_ino, (unsigned long long)ptr);
350                 return -EINVAL;
351         }
352
353         return NILFS_BMAP_USE_VBN(bmap) ?
354                 nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
355                 nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
356 }
357
358 static const struct nilfs_bmap_operations nilfs_direct_ops = {
359         .bop_lookup             =       nilfs_direct_lookup,
360         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
361         .bop_insert             =       nilfs_direct_insert,
362         .bop_delete             =       nilfs_direct_delete,
363         .bop_clear              =       NULL,
364
365         .bop_propagate          =       nilfs_direct_propagate,
366
367         .bop_lookup_dirty_buffers       =       NULL,
368
369         .bop_assign             =       nilfs_direct_assign,
370         .bop_mark               =       NULL,
371
372         .bop_seek_key           =       nilfs_direct_seek_key,
373         .bop_last_key           =       nilfs_direct_last_key,
374
375         .bop_check_insert       =       nilfs_direct_check_insert,
376         .bop_check_delete       =       NULL,
377         .bop_gather_data        =       nilfs_direct_gather_data,
378 };
379
380
381 int nilfs_direct_init(struct nilfs_bmap *bmap)
382 {
383         bmap->b_ops = &nilfs_direct_ops;
384         return 0;
385 }