xref: /linux/fs/quota/quota_v2.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	vfsv0 quota IO operations on file
4  */
5 
6 #include <linux/errno.h>
7 #include <linux/fs.h>
8 #include <linux/mount.h>
9 #include <linux/dqblk_v2.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/quotaops.h>
15 
16 #include <asm/byteorder.h>
17 
18 #include "quota_tree.h"
19 #include "quotaio_v2.h"
20 
21 MODULE_AUTHOR("Jan Kara");
22 MODULE_DESCRIPTION("Quota format v2 support");
23 MODULE_LICENSE("GPL");
24 
25 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
26 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
27 static int v2r0_is_id(void *dp, struct dquot *dquot);
28 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
29 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
30 static int v2r1_is_id(void *dp, struct dquot *dquot);
31 
32 static const struct qtree_fmt_operations v2r0_qtree_ops = {
33 	.mem2disk_dqblk = v2r0_mem2diskdqb,
34 	.disk2mem_dqblk = v2r0_disk2memdqb,
35 	.is_id = v2r0_is_id,
36 };
37 
38 static const struct qtree_fmt_operations v2r1_qtree_ops = {
39 	.mem2disk_dqblk = v2r1_mem2diskdqb,
40 	.disk2mem_dqblk = v2r1_disk2memdqb,
41 	.is_id = v2r1_is_id,
42 };
43 
44 #define QUOTABLOCK_BITS 10
45 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
46 
v2_stoqb(qsize_t space)47 static inline qsize_t v2_stoqb(qsize_t space)
48 {
49 	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
50 }
51 
v2_qbtos(qsize_t blocks)52 static inline qsize_t v2_qbtos(qsize_t blocks)
53 {
54 	return blocks << QUOTABLOCK_BITS;
55 }
56 
v2_read_header(struct super_block * sb,int type,struct v2_disk_dqheader * dqhead)57 static int v2_read_header(struct super_block *sb, int type,
58 			  struct v2_disk_dqheader *dqhead)
59 {
60 	ssize_t size;
61 
62 	size = sb->s_op->quota_read(sb, type, (char *)dqhead,
63 				    sizeof(struct v2_disk_dqheader), 0);
64 	if (size != sizeof(struct v2_disk_dqheader)) {
65 		quota_error(sb, "Failed header read: expected=%zd got=%zd",
66 			    sizeof(struct v2_disk_dqheader), size);
67 		if (size < 0)
68 			return size;
69 		return -EIO;
70 	}
71 	return 0;
72 }
73 
74 /* Check whether given file is really vfsv0 quotafile */
v2_check_quota_file(struct super_block * sb,int type)75 static int v2_check_quota_file(struct super_block *sb, int type)
76 {
77 	struct v2_disk_dqheader dqhead;
78 	static const uint quota_magics[] = V2_INITQMAGICS;
79 	static const uint quota_versions[] = V2_INITQVERSIONS;
80 
81 	if (v2_read_header(sb, type, &dqhead))
82 		return 0;
83 	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
84 	    le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
85 		return 0;
86 	return 1;
87 }
88 
89 /* Read information header from quota file */
v2_read_file_info(struct super_block * sb,int type)90 static int v2_read_file_info(struct super_block *sb, int type)
91 {
92 	struct v2_disk_dqinfo dinfo;
93 	struct v2_disk_dqheader dqhead;
94 	struct quota_info *dqopt = sb_dqopt(sb);
95 	struct mem_dqinfo *info = &dqopt->info[type];
96 	struct qtree_mem_dqinfo *qinfo;
97 	ssize_t size;
98 	unsigned int version;
99 	unsigned int memalloc;
100 	int ret;
101 
102 	down_read(&dqopt->dqio_sem);
103 	memalloc = memalloc_nofs_save();
104 	ret = v2_read_header(sb, type, &dqhead);
105 	if (ret < 0)
106 		goto out;
107 	version = le32_to_cpu(dqhead.dqh_version);
108 	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
109 	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
110 		ret = -EINVAL;
111 		goto out;
112 	}
113 
114 	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
115 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
116 	if (size != sizeof(struct v2_disk_dqinfo)) {
117 		quota_error(sb, "Can't read info structure");
118 		if (size < 0)
119 			ret = size;
120 		else
121 			ret = -EIO;
122 		goto out;
123 	}
124 	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_KERNEL);
125 	if (!info->dqi_priv) {
126 		ret = -ENOMEM;
127 		goto out;
128 	}
129 	qinfo = info->dqi_priv;
130 	if (version == 0) {
131 		/* limits are stored as unsigned 32-bit data */
132 		info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
133 		info->dqi_max_ino_limit = 0xffffffff;
134 	} else {
135 		/*
136 		 * Used space is stored as unsigned 64-bit value in bytes but
137 		 * quota core supports only signed 64-bit values so use that
138 		 * as a limit
139 		 */
140 		info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
141 		info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
142 	}
143 	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
144 	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
145 	/* No flags currently supported */
146 	info->dqi_flags = 0;
147 	qinfo->dqi_sb = sb;
148 	qinfo->dqi_type = type;
149 	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
150 	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
151 	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
152 	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
153 	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
154 	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
155 	if (version == 0) {
156 		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
157 		qinfo->dqi_ops = &v2r0_qtree_ops;
158 	} else {
159 		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
160 		qinfo->dqi_ops = &v2r1_qtree_ops;
161 	}
162 	ret = -EUCLEAN;
163 	/* Some sanity checks of the read headers... */
164 	if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
165 	    i_size_read(sb_dqopt(sb)->files[type])) {
166 		quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
167 		    (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
168 		    i_size_read(sb_dqopt(sb)->files[type]));
169 		goto out_free;
170 	}
171 	if (qinfo->dqi_free_blk && (qinfo->dqi_free_blk <= QT_TREEOFF ||
172 	    qinfo->dqi_free_blk >= qinfo->dqi_blocks)) {
173 		quota_error(sb, "Free block number %u out of range (%u, %u).",
174 			    qinfo->dqi_free_blk, QT_TREEOFF, qinfo->dqi_blocks);
175 		goto out_free;
176 	}
177 	if (qinfo->dqi_free_entry && (qinfo->dqi_free_entry <= QT_TREEOFF ||
178 	    qinfo->dqi_free_entry >= qinfo->dqi_blocks)) {
179 		quota_error(sb, "Block with free entry %u out of range (%u, %u).",
180 			    qinfo->dqi_free_entry, QT_TREEOFF,
181 			    qinfo->dqi_blocks);
182 		goto out_free;
183 	}
184 	ret = 0;
185 out_free:
186 	if (ret) {
187 		kfree(info->dqi_priv);
188 		info->dqi_priv = NULL;
189 	}
190 out:
191 	memalloc_nofs_restore(memalloc);
192 	up_read(&dqopt->dqio_sem);
193 	return ret;
194 }
195 
196 /* Write information header to quota file */
v2_write_file_info(struct super_block * sb,int type)197 static int v2_write_file_info(struct super_block *sb, int type)
198 {
199 	struct v2_disk_dqinfo dinfo;
200 	struct quota_info *dqopt = sb_dqopt(sb);
201 	struct mem_dqinfo *info = &dqopt->info[type];
202 	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
203 	ssize_t size;
204 	unsigned int memalloc;
205 
206 	down_write(&dqopt->dqio_sem);
207 	memalloc = memalloc_nofs_save();
208 	spin_lock(&dq_data_lock);
209 	info->dqi_flags &= ~DQF_INFO_DIRTY;
210 	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
211 	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
212 	/* No flags currently supported */
213 	dinfo.dqi_flags = cpu_to_le32(0);
214 	spin_unlock(&dq_data_lock);
215 	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
216 	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
217 	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
218 	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
219 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
220 	memalloc_nofs_restore(memalloc);
221 	up_write(&dqopt->dqio_sem);
222 	if (size != sizeof(struct v2_disk_dqinfo)) {
223 		quota_error(sb, "Can't write info structure");
224 		return size < 0 ? size : -EIO;
225 	}
226 	return 0;
227 }
228 
v2r0_disk2memdqb(struct dquot * dquot,void * dp)229 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
230 {
231 	struct v2r0_disk_dqblk *d = dp, empty;
232 	struct mem_dqblk *m = &dquot->dq_dqb;
233 
234 	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
235 	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
236 	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
237 	m->dqb_itime = le64_to_cpu(d->dqb_itime);
238 	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
239 	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
240 	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
241 	m->dqb_btime = le64_to_cpu(d->dqb_btime);
242 	/* We need to escape back all-zero structure */
243 	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
244 	empty.dqb_itime = cpu_to_le64(1);
245 	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
246 		m->dqb_itime = 0;
247 }
248 
v2r0_mem2diskdqb(void * dp,struct dquot * dquot)249 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
250 {
251 	struct v2r0_disk_dqblk *d = dp;
252 	struct mem_dqblk *m = &dquot->dq_dqb;
253 	struct qtree_mem_dqinfo *info =
254 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
255 
256 	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
257 	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
258 	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
259 	d->dqb_itime = cpu_to_le64(m->dqb_itime);
260 	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
261 	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
262 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
263 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
264 	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
265 	if (qtree_entry_unused(info, dp))
266 		d->dqb_itime = cpu_to_le64(1);
267 }
268 
v2r0_is_id(void * dp,struct dquot * dquot)269 static int v2r0_is_id(void *dp, struct dquot *dquot)
270 {
271 	struct v2r0_disk_dqblk *d = dp;
272 	struct qtree_mem_dqinfo *info =
273 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
274 
275 	if (qtree_entry_unused(info, dp))
276 		return 0;
277 	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
278 				le32_to_cpu(d->dqb_id)),
279 		      dquot->dq_id);
280 }
281 
v2r1_disk2memdqb(struct dquot * dquot,void * dp)282 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
283 {
284 	struct v2r1_disk_dqblk *d = dp, empty;
285 	struct mem_dqblk *m = &dquot->dq_dqb;
286 
287 	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
288 	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
289 	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
290 	m->dqb_itime = le64_to_cpu(d->dqb_itime);
291 	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
292 	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
293 	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
294 	m->dqb_btime = le64_to_cpu(d->dqb_btime);
295 	/* We need to escape back all-zero structure */
296 	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
297 	empty.dqb_itime = cpu_to_le64(1);
298 	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
299 		m->dqb_itime = 0;
300 }
301 
v2r1_mem2diskdqb(void * dp,struct dquot * dquot)302 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
303 {
304 	struct v2r1_disk_dqblk *d = dp;
305 	struct mem_dqblk *m = &dquot->dq_dqb;
306 	struct qtree_mem_dqinfo *info =
307 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
308 
309 	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
310 	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
311 	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
312 	d->dqb_itime = cpu_to_le64(m->dqb_itime);
313 	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
314 	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
315 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
316 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
317 	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
318 	d->dqb_pad = 0;
319 	if (qtree_entry_unused(info, dp))
320 		d->dqb_itime = cpu_to_le64(1);
321 }
322 
v2r1_is_id(void * dp,struct dquot * dquot)323 static int v2r1_is_id(void *dp, struct dquot *dquot)
324 {
325 	struct v2r1_disk_dqblk *d = dp;
326 	struct qtree_mem_dqinfo *info =
327 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
328 
329 	if (qtree_entry_unused(info, dp))
330 		return 0;
331 	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
332 				le32_to_cpu(d->dqb_id)),
333 		      dquot->dq_id);
334 }
335 
v2_read_dquot(struct dquot * dquot)336 static int v2_read_dquot(struct dquot *dquot)
337 {
338 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
339 	int ret;
340 	unsigned int memalloc;
341 
342 	down_read(&dqopt->dqio_sem);
343 	memalloc = memalloc_nofs_save();
344 	ret = qtree_read_dquot(
345 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
346 			dquot);
347 	memalloc_nofs_restore(memalloc);
348 	up_read(&dqopt->dqio_sem);
349 	return ret;
350 }
351 
v2_write_dquot(struct dquot * dquot)352 static int v2_write_dquot(struct dquot *dquot)
353 {
354 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
355 	int ret;
356 	bool alloc = false;
357 	unsigned int memalloc;
358 
359 	/*
360 	 * If space for dquot is already allocated, we don't need any
361 	 * protection as we'll only overwrite the place of dquot. We are
362 	 * still protected by concurrent writes of the same dquot by
363 	 * dquot->dq_lock.
364 	 */
365 	if (!dquot->dq_off) {
366 		alloc = true;
367 		down_write(&dqopt->dqio_sem);
368 	} else {
369 		down_read(&dqopt->dqio_sem);
370 	}
371 	memalloc = memalloc_nofs_save();
372 	ret = qtree_write_dquot(
373 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
374 			dquot);
375 	memalloc_nofs_restore(memalloc);
376 	if (alloc)
377 		up_write(&dqopt->dqio_sem);
378 	else
379 		up_read(&dqopt->dqio_sem);
380 	return ret;
381 }
382 
v2_release_dquot(struct dquot * dquot)383 static int v2_release_dquot(struct dquot *dquot)
384 {
385 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
386 	unsigned int memalloc;
387 	int ret;
388 
389 	down_write(&dqopt->dqio_sem);
390 	memalloc = memalloc_nofs_save();
391 	ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
392 	memalloc_nofs_restore(memalloc);
393 	up_write(&dqopt->dqio_sem);
394 
395 	return ret;
396 }
397 
v2_free_file_info(struct super_block * sb,int type)398 static int v2_free_file_info(struct super_block *sb, int type)
399 {
400 	kfree(sb_dqinfo(sb, type)->dqi_priv);
401 	return 0;
402 }
403 
v2_get_next_id(struct super_block * sb,struct kqid * qid)404 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
405 {
406 	struct quota_info *dqopt = sb_dqopt(sb);
407 	unsigned int memalloc;
408 	int ret;
409 
410 	down_read(&dqopt->dqio_sem);
411 	memalloc = memalloc_nofs_save();
412 	ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
413 	memalloc_nofs_restore(memalloc);
414 	up_read(&dqopt->dqio_sem);
415 	return ret;
416 }
417 
418 static const struct quota_format_ops v2_format_ops = {
419 	.check_quota_file	= v2_check_quota_file,
420 	.read_file_info		= v2_read_file_info,
421 	.write_file_info	= v2_write_file_info,
422 	.free_file_info		= v2_free_file_info,
423 	.read_dqblk		= v2_read_dquot,
424 	.commit_dqblk		= v2_write_dquot,
425 	.release_dqblk		= v2_release_dquot,
426 	.get_next_id		= v2_get_next_id,
427 };
428 
429 static struct quota_format_type v2r0_quota_format = {
430 	.qf_fmt_id	= QFMT_VFS_V0,
431 	.qf_ops		= &v2_format_ops,
432 	.qf_owner	= THIS_MODULE
433 };
434 
435 static struct quota_format_type v2r1_quota_format = {
436 	.qf_fmt_id	= QFMT_VFS_V1,
437 	.qf_ops		= &v2_format_ops,
438 	.qf_owner	= THIS_MODULE
439 };
440 
init_v2_quota_format(void)441 static int __init init_v2_quota_format(void)
442 {
443 	register_quota_format(&v2r0_quota_format);
444 	register_quota_format(&v2r1_quota_format);
445 	return 0;
446 }
447 
exit_v2_quota_format(void)448 static void __exit exit_v2_quota_format(void)
449 {
450 	unregister_quota_format(&v2r0_quota_format);
451 	unregister_quota_format(&v2r1_quota_format);
452 }
453 
454 module_init(init_v2_quota_format);
455 module_exit(exit_v2_quota_format);
456