Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/fs/quota_v2.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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File size: 20547 byte(s)
Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 20547 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * vfsv0 quota IO operations on file |
3 | */ |
4 | |
5 | #include <linux/errno.h> |
6 | #include <linux/fs.h> |
7 | #include <linux/mount.h> |
8 | #include <linux/dqblk_v2.h> |
9 | #include <linux/quotaio_v2.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/init.h> |
12 | #include <linux/module.h> |
13 | #include <linux/slab.h> |
14 | |
15 | #include <asm/byteorder.h> |
16 | |
17 | MODULE_AUTHOR("Jan Kara"); |
18 | MODULE_DESCRIPTION("Quota format v2 support"); |
19 | MODULE_LICENSE("GPL"); |
20 | |
21 | #define __QUOTA_V2_PARANOIA |
22 | |
23 | typedef char *dqbuf_t; |
24 | |
25 | #define GETIDINDEX(id, depth) (((id) >> ((V2_DQTREEDEPTH-(depth)-1)*8)) & 0xff) |
26 | #define GETENTRIES(buf) ((struct v2_disk_dqblk *)(((char *)buf)+sizeof(struct v2_disk_dqdbheader))) |
27 | |
28 | /* Check whether given file is really vfsv0 quotafile */ |
29 | static int v2_check_quota_file(struct super_block *sb, int type) |
30 | { |
31 | struct v2_disk_dqheader dqhead; |
32 | ssize_t size; |
33 | static const uint quota_magics[] = V2_INITQMAGICS; |
34 | static const uint quota_versions[] = V2_INITQVERSIONS; |
35 | |
36 | size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0); |
37 | if (size != sizeof(struct v2_disk_dqheader)) { |
38 | printk("failed read\n"); |
39 | return 0; |
40 | } |
41 | if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] || |
42 | le32_to_cpu(dqhead.dqh_version) != quota_versions[type]) |
43 | return 0; |
44 | return 1; |
45 | } |
46 | |
47 | /* Read information header from quota file */ |
48 | static int v2_read_file_info(struct super_block *sb, int type) |
49 | { |
50 | struct v2_disk_dqinfo dinfo; |
51 | struct mem_dqinfo *info = sb_dqopt(sb)->info+type; |
52 | ssize_t size; |
53 | |
54 | size = sb->s_op->quota_read(sb, type, (char *)&dinfo, |
55 | sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); |
56 | if (size != sizeof(struct v2_disk_dqinfo)) { |
57 | printk(KERN_WARNING "Can't read info structure on device %s.\n", |
58 | sb->s_id); |
59 | return -1; |
60 | } |
61 | info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace); |
62 | info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace); |
63 | info->dqi_flags = le32_to_cpu(dinfo.dqi_flags); |
64 | info->u.v2_i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks); |
65 | info->u.v2_i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk); |
66 | info->u.v2_i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry); |
67 | return 0; |
68 | } |
69 | |
70 | /* Write information header to quota file */ |
71 | static int v2_write_file_info(struct super_block *sb, int type) |
72 | { |
73 | struct v2_disk_dqinfo dinfo; |
74 | struct mem_dqinfo *info = sb_dqopt(sb)->info+type; |
75 | ssize_t size; |
76 | |
77 | spin_lock(&dq_data_lock); |
78 | info->dqi_flags &= ~DQF_INFO_DIRTY; |
79 | dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace); |
80 | dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace); |
81 | dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK); |
82 | spin_unlock(&dq_data_lock); |
83 | dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.dqi_blocks); |
84 | dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.dqi_free_blk); |
85 | dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.dqi_free_entry); |
86 | size = sb->s_op->quota_write(sb, type, (char *)&dinfo, |
87 | sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); |
88 | if (size != sizeof(struct v2_disk_dqinfo)) { |
89 | printk(KERN_WARNING "Can't write info structure on device %s.\n", |
90 | sb->s_id); |
91 | return -1; |
92 | } |
93 | return 0; |
94 | } |
95 | |
96 | static void disk2memdqb(struct mem_dqblk *m, struct v2_disk_dqblk *d) |
97 | { |
98 | m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit); |
99 | m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit); |
100 | m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes); |
101 | m->dqb_itime = le64_to_cpu(d->dqb_itime); |
102 | m->dqb_bhardlimit = le32_to_cpu(d->dqb_bhardlimit); |
103 | m->dqb_bsoftlimit = le32_to_cpu(d->dqb_bsoftlimit); |
104 | m->dqb_curspace = le64_to_cpu(d->dqb_curspace); |
105 | m->dqb_btime = le64_to_cpu(d->dqb_btime); |
106 | } |
107 | |
108 | static void mem2diskdqb(struct v2_disk_dqblk *d, struct mem_dqblk *m, qid_t id) |
109 | { |
110 | d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit); |
111 | d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit); |
112 | d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes); |
113 | d->dqb_itime = cpu_to_le64(m->dqb_itime); |
114 | d->dqb_bhardlimit = cpu_to_le32(m->dqb_bhardlimit); |
115 | d->dqb_bsoftlimit = cpu_to_le32(m->dqb_bsoftlimit); |
116 | d->dqb_curspace = cpu_to_le64(m->dqb_curspace); |
117 | d->dqb_btime = cpu_to_le64(m->dqb_btime); |
118 | d->dqb_id = cpu_to_le32(id); |
119 | } |
120 | |
121 | static dqbuf_t getdqbuf(void) |
122 | { |
123 | dqbuf_t buf = kmalloc(V2_DQBLKSIZE, GFP_NOFS); |
124 | if (!buf) |
125 | printk(KERN_WARNING "VFS: Not enough memory for quota buffers.\n"); |
126 | return buf; |
127 | } |
128 | |
129 | static inline void freedqbuf(dqbuf_t buf) |
130 | { |
131 | kfree(buf); |
132 | } |
133 | |
134 | static inline ssize_t read_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf) |
135 | { |
136 | memset(buf, 0, V2_DQBLKSIZE); |
137 | return sb->s_op->quota_read(sb, type, (char *)buf, |
138 | V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS); |
139 | } |
140 | |
141 | static inline ssize_t write_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf) |
142 | { |
143 | return sb->s_op->quota_write(sb, type, (char *)buf, |
144 | V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS); |
145 | } |
146 | |
147 | /* Remove empty block from list and return it */ |
148 | static int get_free_dqblk(struct super_block *sb, int type) |
149 | { |
150 | dqbuf_t buf = getdqbuf(); |
151 | struct mem_dqinfo *info = sb_dqinfo(sb, type); |
152 | struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf; |
153 | int ret, blk; |
154 | |
155 | if (!buf) |
156 | return -ENOMEM; |
157 | if (info->u.v2_i.dqi_free_blk) { |
158 | blk = info->u.v2_i.dqi_free_blk; |
159 | if ((ret = read_blk(sb, type, blk, buf)) < 0) |
160 | goto out_buf; |
161 | info->u.v2_i.dqi_free_blk = le32_to_cpu(dh->dqdh_next_free); |
162 | } |
163 | else { |
164 | memset(buf, 0, V2_DQBLKSIZE); |
165 | /* Assure block allocation... */ |
166 | if ((ret = write_blk(sb, type, info->u.v2_i.dqi_blocks, buf)) < 0) |
167 | goto out_buf; |
168 | blk = info->u.v2_i.dqi_blocks++; |
169 | } |
170 | mark_info_dirty(sb, type); |
171 | ret = blk; |
172 | out_buf: |
173 | freedqbuf(buf); |
174 | return ret; |
175 | } |
176 | |
177 | /* Insert empty block to the list */ |
178 | static int put_free_dqblk(struct super_block *sb, int type, dqbuf_t buf, uint blk) |
179 | { |
180 | struct mem_dqinfo *info = sb_dqinfo(sb, type); |
181 | struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf; |
182 | int err; |
183 | |
184 | dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_blk); |
185 | dh->dqdh_prev_free = cpu_to_le32(0); |
186 | dh->dqdh_entries = cpu_to_le16(0); |
187 | info->u.v2_i.dqi_free_blk = blk; |
188 | mark_info_dirty(sb, type); |
189 | /* Some strange block. We had better leave it... */ |
190 | if ((err = write_blk(sb, type, blk, buf)) < 0) |
191 | return err; |
192 | return 0; |
193 | } |
194 | |
195 | /* Remove given block from the list of blocks with free entries */ |
196 | static int remove_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk) |
197 | { |
198 | dqbuf_t tmpbuf = getdqbuf(); |
199 | struct mem_dqinfo *info = sb_dqinfo(sb, type); |
200 | struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf; |
201 | uint nextblk = le32_to_cpu(dh->dqdh_next_free), prevblk = le32_to_cpu(dh->dqdh_prev_free); |
202 | int err; |
203 | |
204 | if (!tmpbuf) |
205 | return -ENOMEM; |
206 | if (nextblk) { |
207 | if ((err = read_blk(sb, type, nextblk, tmpbuf)) < 0) |
208 | goto out_buf; |
209 | ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = dh->dqdh_prev_free; |
210 | if ((err = write_blk(sb, type, nextblk, tmpbuf)) < 0) |
211 | goto out_buf; |
212 | } |
213 | if (prevblk) { |
214 | if ((err = read_blk(sb, type, prevblk, tmpbuf)) < 0) |
215 | goto out_buf; |
216 | ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_next_free = dh->dqdh_next_free; |
217 | if ((err = write_blk(sb, type, prevblk, tmpbuf)) < 0) |
218 | goto out_buf; |
219 | } |
220 | else { |
221 | info->u.v2_i.dqi_free_entry = nextblk; |
222 | mark_info_dirty(sb, type); |
223 | } |
224 | freedqbuf(tmpbuf); |
225 | dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0); |
226 | /* No matter whether write succeeds block is out of list */ |
227 | if (write_blk(sb, type, blk, buf) < 0) |
228 | printk(KERN_ERR "VFS: Can't write block (%u) with free entries.\n", blk); |
229 | return 0; |
230 | out_buf: |
231 | freedqbuf(tmpbuf); |
232 | return err; |
233 | } |
234 | |
235 | /* Insert given block to the beginning of list with free entries */ |
236 | static int insert_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk) |
237 | { |
238 | dqbuf_t tmpbuf = getdqbuf(); |
239 | struct mem_dqinfo *info = sb_dqinfo(sb, type); |
240 | struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf; |
241 | int err; |
242 | |
243 | if (!tmpbuf) |
244 | return -ENOMEM; |
245 | dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_entry); |
246 | dh->dqdh_prev_free = cpu_to_le32(0); |
247 | if ((err = write_blk(sb, type, blk, buf)) < 0) |
248 | goto out_buf; |
249 | if (info->u.v2_i.dqi_free_entry) { |
250 | if ((err = read_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0) |
251 | goto out_buf; |
252 | ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = cpu_to_le32(blk); |
253 | if ((err = write_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0) |
254 | goto out_buf; |
255 | } |
256 | freedqbuf(tmpbuf); |
257 | info->u.v2_i.dqi_free_entry = blk; |
258 | mark_info_dirty(sb, type); |
259 | return 0; |
260 | out_buf: |
261 | freedqbuf(tmpbuf); |
262 | return err; |
263 | } |
264 | |
265 | /* Find space for dquot */ |
266 | static uint find_free_dqentry(struct dquot *dquot, int *err) |
267 | { |
268 | struct super_block *sb = dquot->dq_sb; |
269 | struct mem_dqinfo *info = sb_dqopt(sb)->info+dquot->dq_type; |
270 | uint blk, i; |
271 | struct v2_disk_dqdbheader *dh; |
272 | struct v2_disk_dqblk *ddquot; |
273 | struct v2_disk_dqblk fakedquot; |
274 | dqbuf_t buf; |
275 | |
276 | *err = 0; |
277 | if (!(buf = getdqbuf())) { |
278 | *err = -ENOMEM; |
279 | return 0; |
280 | } |
281 | dh = (struct v2_disk_dqdbheader *)buf; |
282 | ddquot = GETENTRIES(buf); |
283 | if (info->u.v2_i.dqi_free_entry) { |
284 | blk = info->u.v2_i.dqi_free_entry; |
285 | if ((*err = read_blk(sb, dquot->dq_type, blk, buf)) < 0) |
286 | goto out_buf; |
287 | } |
288 | else { |
289 | blk = get_free_dqblk(sb, dquot->dq_type); |
290 | if ((int)blk < 0) { |
291 | *err = blk; |
292 | freedqbuf(buf); |
293 | return 0; |
294 | } |
295 | memset(buf, 0, V2_DQBLKSIZE); |
296 | /* This is enough as block is already zeroed and entry list is empty... */ |
297 | info->u.v2_i.dqi_free_entry = blk; |
298 | mark_info_dirty(sb, dquot->dq_type); |
299 | } |
300 | if (le16_to_cpu(dh->dqdh_entries)+1 >= V2_DQSTRINBLK) /* Block will be full? */ |
301 | if ((*err = remove_free_dqentry(sb, dquot->dq_type, buf, blk)) < 0) { |
302 | printk(KERN_ERR "VFS: find_free_dqentry(): Can't remove block (%u) from entry free list.\n", blk); |
303 | goto out_buf; |
304 | } |
305 | dh->dqdh_entries = cpu_to_le16(le16_to_cpu(dh->dqdh_entries)+1); |
306 | memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk)); |
307 | /* Find free structure in block */ |
308 | for (i = 0; i < V2_DQSTRINBLK && memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk)); i++); |
309 | #ifdef __QUOTA_V2_PARANOIA |
310 | if (i == V2_DQSTRINBLK) { |
311 | printk(KERN_ERR "VFS: find_free_dqentry(): Data block full but it shouldn't.\n"); |
312 | *err = -EIO; |
313 | goto out_buf; |
314 | } |
315 | #endif |
316 | if ((*err = write_blk(sb, dquot->dq_type, blk, buf)) < 0) { |
317 | printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota data block %u.\n", blk); |
318 | goto out_buf; |
319 | } |
320 | dquot->dq_off = (blk<<V2_DQBLKSIZE_BITS)+sizeof(struct v2_disk_dqdbheader)+i*sizeof(struct v2_disk_dqblk); |
321 | freedqbuf(buf); |
322 | return blk; |
323 | out_buf: |
324 | freedqbuf(buf); |
325 | return 0; |
326 | } |
327 | |
328 | /* Insert reference to structure into the trie */ |
329 | static int do_insert_tree(struct dquot *dquot, uint *treeblk, int depth) |
330 | { |
331 | struct super_block *sb = dquot->dq_sb; |
332 | dqbuf_t buf; |
333 | int ret = 0, newson = 0, newact = 0; |
334 | __le32 *ref; |
335 | uint newblk; |
336 | |
337 | if (!(buf = getdqbuf())) |
338 | return -ENOMEM; |
339 | if (!*treeblk) { |
340 | ret = get_free_dqblk(sb, dquot->dq_type); |
341 | if (ret < 0) |
342 | goto out_buf; |
343 | *treeblk = ret; |
344 | memset(buf, 0, V2_DQBLKSIZE); |
345 | newact = 1; |
346 | } |
347 | else { |
348 | if ((ret = read_blk(sb, dquot->dq_type, *treeblk, buf)) < 0) { |
349 | printk(KERN_ERR "VFS: Can't read tree quota block %u.\n", *treeblk); |
350 | goto out_buf; |
351 | } |
352 | } |
353 | ref = (__le32 *)buf; |
354 | newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]); |
355 | if (!newblk) |
356 | newson = 1; |
357 | if (depth == V2_DQTREEDEPTH-1) { |
358 | #ifdef __QUOTA_V2_PARANOIA |
359 | if (newblk) { |
360 | printk(KERN_ERR "VFS: Inserting already present quota entry (block %u).\n", le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)])); |
361 | ret = -EIO; |
362 | goto out_buf; |
363 | } |
364 | #endif |
365 | newblk = find_free_dqentry(dquot, &ret); |
366 | } |
367 | else |
368 | ret = do_insert_tree(dquot, &newblk, depth+1); |
369 | if (newson && ret >= 0) { |
370 | ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(newblk); |
371 | ret = write_blk(sb, dquot->dq_type, *treeblk, buf); |
372 | } |
373 | else if (newact && ret < 0) |
374 | put_free_dqblk(sb, dquot->dq_type, buf, *treeblk); |
375 | out_buf: |
376 | freedqbuf(buf); |
377 | return ret; |
378 | } |
379 | |
380 | /* Wrapper for inserting quota structure into tree */ |
381 | static inline int dq_insert_tree(struct dquot *dquot) |
382 | { |
383 | int tmp = V2_DQTREEOFF; |
384 | return do_insert_tree(dquot, &tmp, 0); |
385 | } |
386 | |
387 | /* |
388 | * We don't have to be afraid of deadlocks as we never have quotas on quota files... |
389 | */ |
390 | static int v2_write_dquot(struct dquot *dquot) |
391 | { |
392 | int type = dquot->dq_type; |
393 | ssize_t ret; |
394 | struct v2_disk_dqblk ddquot, empty; |
395 | |
396 | /* dq_off is guarded by dqio_sem */ |
397 | if (!dquot->dq_off) |
398 | if ((ret = dq_insert_tree(dquot)) < 0) { |
399 | printk(KERN_ERR "VFS: Error %zd occurred while creating quota.\n", ret); |
400 | return ret; |
401 | } |
402 | spin_lock(&dq_data_lock); |
403 | mem2diskdqb(&ddquot, &dquot->dq_dqb, dquot->dq_id); |
404 | /* Argh... We may need to write structure full of zeroes but that would be |
405 | * treated as an empty place by the rest of the code. Format change would |
406 | * be definitely cleaner but the problems probably are not worth it */ |
407 | memset(&empty, 0, sizeof(struct v2_disk_dqblk)); |
408 | if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk))) |
409 | ddquot.dqb_itime = cpu_to_le64(1); |
410 | spin_unlock(&dq_data_lock); |
411 | ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, |
412 | (char *)&ddquot, sizeof(struct v2_disk_dqblk), dquot->dq_off); |
413 | if (ret != sizeof(struct v2_disk_dqblk)) { |
414 | printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", dquot->dq_sb->s_id); |
415 | if (ret >= 0) |
416 | ret = -ENOSPC; |
417 | } |
418 | else |
419 | ret = 0; |
420 | dqstats.writes++; |
421 | |
422 | return ret; |
423 | } |
424 | |
425 | /* Free dquot entry in data block */ |
426 | static int free_dqentry(struct dquot *dquot, uint blk) |
427 | { |
428 | struct super_block *sb = dquot->dq_sb; |
429 | int type = dquot->dq_type; |
430 | struct v2_disk_dqdbheader *dh; |
431 | dqbuf_t buf = getdqbuf(); |
432 | int ret = 0; |
433 | |
434 | if (!buf) |
435 | return -ENOMEM; |
436 | if (dquot->dq_off >> V2_DQBLKSIZE_BITS != blk) { |
437 | printk(KERN_ERR "VFS: Quota structure has offset to other " |
438 | "block (%u) than it should (%u).\n", blk, |
439 | (uint)(dquot->dq_off >> V2_DQBLKSIZE_BITS)); |
440 | goto out_buf; |
441 | } |
442 | if ((ret = read_blk(sb, type, blk, buf)) < 0) { |
443 | printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk); |
444 | goto out_buf; |
445 | } |
446 | dh = (struct v2_disk_dqdbheader *)buf; |
447 | dh->dqdh_entries = cpu_to_le16(le16_to_cpu(dh->dqdh_entries)-1); |
448 | if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */ |
449 | if ((ret = remove_free_dqentry(sb, type, buf, blk)) < 0 || |
450 | (ret = put_free_dqblk(sb, type, buf, blk)) < 0) { |
451 | printk(KERN_ERR "VFS: Can't move quota data block (%u) " |
452 | "to free list.\n", blk); |
453 | goto out_buf; |
454 | } |
455 | } |
456 | else { |
457 | memset(buf+(dquot->dq_off & ((1 << V2_DQBLKSIZE_BITS)-1)), 0, |
458 | sizeof(struct v2_disk_dqblk)); |
459 | if (le16_to_cpu(dh->dqdh_entries) == V2_DQSTRINBLK-1) { |
460 | /* Insert will write block itself */ |
461 | if ((ret = insert_free_dqentry(sb, type, buf, blk)) < 0) { |
462 | printk(KERN_ERR "VFS: Can't insert quota data block (%u) to free entry list.\n", blk); |
463 | goto out_buf; |
464 | } |
465 | } |
466 | else |
467 | if ((ret = write_blk(sb, type, blk, buf)) < 0) { |
468 | printk(KERN_ERR "VFS: Can't write quota data " |
469 | "block %u\n", blk); |
470 | goto out_buf; |
471 | } |
472 | } |
473 | dquot->dq_off = 0; /* Quota is now unattached */ |
474 | out_buf: |
475 | freedqbuf(buf); |
476 | return ret; |
477 | } |
478 | |
479 | /* Remove reference to dquot from tree */ |
480 | static int remove_tree(struct dquot *dquot, uint *blk, int depth) |
481 | { |
482 | struct super_block *sb = dquot->dq_sb; |
483 | int type = dquot->dq_type; |
484 | dqbuf_t buf = getdqbuf(); |
485 | int ret = 0; |
486 | uint newblk; |
487 | __le32 *ref = (__le32 *)buf; |
488 | |
489 | if (!buf) |
490 | return -ENOMEM; |
491 | if ((ret = read_blk(sb, type, *blk, buf)) < 0) { |
492 | printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk); |
493 | goto out_buf; |
494 | } |
495 | newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]); |
496 | if (depth == V2_DQTREEDEPTH-1) { |
497 | ret = free_dqentry(dquot, newblk); |
498 | newblk = 0; |
499 | } |
500 | else |
501 | ret = remove_tree(dquot, &newblk, depth+1); |
502 | if (ret >= 0 && !newblk) { |
503 | int i; |
504 | ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(0); |
505 | for (i = 0; i < V2_DQBLKSIZE && !buf[i]; i++); /* Block got empty? */ |
506 | /* Don't put the root block into the free block list */ |
507 | if (i == V2_DQBLKSIZE && *blk != V2_DQTREEOFF) { |
508 | put_free_dqblk(sb, type, buf, *blk); |
509 | *blk = 0; |
510 | } |
511 | else |
512 | if ((ret = write_blk(sb, type, *blk, buf)) < 0) |
513 | printk(KERN_ERR "VFS: Can't write quota tree " |
514 | "block %u.\n", *blk); |
515 | } |
516 | out_buf: |
517 | freedqbuf(buf); |
518 | return ret; |
519 | } |
520 | |
521 | /* Delete dquot from tree */ |
522 | static int v2_delete_dquot(struct dquot *dquot) |
523 | { |
524 | uint tmp = V2_DQTREEOFF; |
525 | |
526 | if (!dquot->dq_off) /* Even not allocated? */ |
527 | return 0; |
528 | return remove_tree(dquot, &tmp, 0); |
529 | } |
530 | |
531 | /* Find entry in block */ |
532 | static loff_t find_block_dqentry(struct dquot *dquot, uint blk) |
533 | { |
534 | dqbuf_t buf = getdqbuf(); |
535 | loff_t ret = 0; |
536 | int i; |
537 | struct v2_disk_dqblk *ddquot = GETENTRIES(buf); |
538 | |
539 | if (!buf) |
540 | return -ENOMEM; |
541 | if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) { |
542 | printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk); |
543 | goto out_buf; |
544 | } |
545 | if (dquot->dq_id) |
546 | for (i = 0; i < V2_DQSTRINBLK && |
547 | le32_to_cpu(ddquot[i].dqb_id) != dquot->dq_id; i++); |
548 | else { /* ID 0 as a bit more complicated searching... */ |
549 | struct v2_disk_dqblk fakedquot; |
550 | |
551 | memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk)); |
552 | for (i = 0; i < V2_DQSTRINBLK; i++) |
553 | if (!le32_to_cpu(ddquot[i].dqb_id) && |
554 | memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk))) |
555 | break; |
556 | } |
557 | if (i == V2_DQSTRINBLK) { |
558 | printk(KERN_ERR "VFS: Quota for id %u referenced " |
559 | "but not present.\n", dquot->dq_id); |
560 | ret = -EIO; |
561 | goto out_buf; |
562 | } |
563 | else |
564 | ret = (blk << V2_DQBLKSIZE_BITS) + sizeof(struct |
565 | v2_disk_dqdbheader) + i * sizeof(struct v2_disk_dqblk); |
566 | out_buf: |
567 | freedqbuf(buf); |
568 | return ret; |
569 | } |
570 | |
571 | /* Find entry for given id in the tree */ |
572 | static loff_t find_tree_dqentry(struct dquot *dquot, uint blk, int depth) |
573 | { |
574 | dqbuf_t buf = getdqbuf(); |
575 | loff_t ret = 0; |
576 | __le32 *ref = (__le32 *)buf; |
577 | |
578 | if (!buf) |
579 | return -ENOMEM; |
580 | if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) { |
581 | printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk); |
582 | goto out_buf; |
583 | } |
584 | ret = 0; |
585 | blk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]); |
586 | if (!blk) /* No reference? */ |
587 | goto out_buf; |
588 | if (depth < V2_DQTREEDEPTH-1) |
589 | ret = find_tree_dqentry(dquot, blk, depth+1); |
590 | else |
591 | ret = find_block_dqentry(dquot, blk); |
592 | out_buf: |
593 | freedqbuf(buf); |
594 | return ret; |
595 | } |
596 | |
597 | /* Find entry for given id in the tree - wrapper function */ |
598 | static inline loff_t find_dqentry(struct dquot *dquot) |
599 | { |
600 | return find_tree_dqentry(dquot, V2_DQTREEOFF, 0); |
601 | } |
602 | |
603 | static int v2_read_dquot(struct dquot *dquot) |
604 | { |
605 | int type = dquot->dq_type; |
606 | loff_t offset; |
607 | struct v2_disk_dqblk ddquot, empty; |
608 | int ret = 0; |
609 | |
610 | #ifdef __QUOTA_V2_PARANOIA |
611 | /* Invalidated quota? */ |
612 | if (!dquot->dq_sb || !sb_dqopt(dquot->dq_sb)->files[type]) { |
613 | printk(KERN_ERR "VFS: Quota invalidated while reading!\n"); |
614 | return -EIO; |
615 | } |
616 | #endif |
617 | offset = find_dqentry(dquot); |
618 | if (offset <= 0) { /* Entry not present? */ |
619 | if (offset < 0) |
620 | printk(KERN_ERR "VFS: Can't read quota " |
621 | "structure for id %u.\n", dquot->dq_id); |
622 | dquot->dq_off = 0; |
623 | set_bit(DQ_FAKE_B, &dquot->dq_flags); |
624 | memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk)); |
625 | ret = offset; |
626 | } |
627 | else { |
628 | dquot->dq_off = offset; |
629 | if ((ret = dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, |
630 | (char *)&ddquot, sizeof(struct v2_disk_dqblk), offset)) |
631 | != sizeof(struct v2_disk_dqblk)) { |
632 | if (ret >= 0) |
633 | ret = -EIO; |
634 | printk(KERN_ERR "VFS: Error while reading quota " |
635 | "structure for id %u.\n", dquot->dq_id); |
636 | memset(&ddquot, 0, sizeof(struct v2_disk_dqblk)); |
637 | } |
638 | else { |
639 | ret = 0; |
640 | /* We need to escape back all-zero structure */ |
641 | memset(&empty, 0, sizeof(struct v2_disk_dqblk)); |
642 | empty.dqb_itime = cpu_to_le64(1); |
643 | if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk))) |
644 | ddquot.dqb_itime = 0; |
645 | } |
646 | disk2memdqb(&dquot->dq_dqb, &ddquot); |
647 | if (!dquot->dq_dqb.dqb_bhardlimit && |
648 | !dquot->dq_dqb.dqb_bsoftlimit && |
649 | !dquot->dq_dqb.dqb_ihardlimit && |
650 | !dquot->dq_dqb.dqb_isoftlimit) |
651 | set_bit(DQ_FAKE_B, &dquot->dq_flags); |
652 | } |
653 | dqstats.reads++; |
654 | |
655 | return ret; |
656 | } |
657 | |
658 | /* Check whether dquot should not be deleted. We know we are |
659 | * the only one operating on dquot (thanks to dq_lock) */ |
660 | static int v2_release_dquot(struct dquot *dquot) |
661 | { |
662 | if (test_bit(DQ_FAKE_B, &dquot->dq_flags) && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace)) |
663 | return v2_delete_dquot(dquot); |
664 | return 0; |
665 | } |
666 | |
667 | static struct quota_format_ops v2_format_ops = { |
668 | .check_quota_file = v2_check_quota_file, |
669 | .read_file_info = v2_read_file_info, |
670 | .write_file_info = v2_write_file_info, |
671 | .free_file_info = NULL, |
672 | .read_dqblk = v2_read_dquot, |
673 | .commit_dqblk = v2_write_dquot, |
674 | .release_dqblk = v2_release_dquot, |
675 | }; |
676 | |
677 | static struct quota_format_type v2_quota_format = { |
678 | .qf_fmt_id = QFMT_VFS_V0, |
679 | .qf_ops = &v2_format_ops, |
680 | .qf_owner = THIS_MODULE |
681 | }; |
682 | |
683 | static int __init init_v2_quota_format(void) |
684 | { |
685 | return register_quota_format(&v2_quota_format); |
686 | } |
687 | |
688 | static void __exit exit_v2_quota_format(void) |
689 | { |
690 | unregister_quota_format(&v2_quota_format); |
691 | } |
692 | |
693 | module_init(init_v2_quota_format); |
694 | module_exit(exit_v2_quota_format); |