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 #define __QUOTA_V2_PARANOIA 26 27 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot); 28 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp); 29 static int v2r0_is_id(void *dp, struct dquot *dquot); 30 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot); 31 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp); 32 static int v2r1_is_id(void *dp, struct dquot *dquot); 33 34 static const struct qtree_fmt_operations v2r0_qtree_ops = { 35 .mem2disk_dqblk = v2r0_mem2diskdqb, 36 .disk2mem_dqblk = v2r0_disk2memdqb, 37 .is_id = v2r0_is_id, 38 }; 39 40 static const struct qtree_fmt_operations v2r1_qtree_ops = { 41 .mem2disk_dqblk = v2r1_mem2diskdqb, 42 .disk2mem_dqblk = v2r1_disk2memdqb, 43 .is_id = v2r1_is_id, 44 }; 45 46 #define QUOTABLOCK_BITS 10 47 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS) 48 49 static inline qsize_t v2_stoqb(qsize_t space) 50 { 51 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS; 52 } 53 54 static inline qsize_t v2_qbtos(qsize_t blocks) 55 { 56 return blocks << QUOTABLOCK_BITS; 57 } 58 59 static int v2_read_header(struct super_block *sb, int type, 60 struct v2_disk_dqheader *dqhead) 61 { 62 ssize_t size; 63 64 size = sb->s_op->quota_read(sb, type, (char *)dqhead, 65 sizeof(struct v2_disk_dqheader), 0); 66 if (size != sizeof(struct v2_disk_dqheader)) { 67 quota_error(sb, "Failed header read: expected=%zd got=%zd", 68 sizeof(struct v2_disk_dqheader), size); 69 if (size < 0) 70 return size; 71 return -EIO; 72 } 73 return 0; 74 } 75 76 /* Check whether given file is really vfsv0 quotafile */ 77 static int v2_check_quota_file(struct super_block *sb, int type) 78 { 79 struct v2_disk_dqheader dqhead; 80 static const uint quota_magics[] = V2_INITQMAGICS; 81 static const uint quota_versions[] = V2_INITQVERSIONS; 82 83 if (v2_read_header(sb, type, &dqhead)) 84 return 0; 85 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] || 86 le32_to_cpu(dqhead.dqh_version) > quota_versions[type]) 87 return 0; 88 return 1; 89 } 90 91 /* Read information header from quota file */ 92 static int v2_read_file_info(struct super_block *sb, int type) 93 { 94 struct v2_disk_dqinfo dinfo; 95 struct v2_disk_dqheader dqhead; 96 struct quota_info *dqopt = sb_dqopt(sb); 97 struct mem_dqinfo *info = &dqopt->info[type]; 98 struct qtree_mem_dqinfo *qinfo; 99 ssize_t size; 100 unsigned int version; 101 int ret; 102 103 down_read(&dqopt->dqio_sem); 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_NOFS); 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 = 0; 163 out: 164 up_read(&dqopt->dqio_sem); 165 return ret; 166 } 167 168 /* Write information header to quota file */ 169 static int v2_write_file_info(struct super_block *sb, int type) 170 { 171 struct v2_disk_dqinfo dinfo; 172 struct quota_info *dqopt = sb_dqopt(sb); 173 struct mem_dqinfo *info = &dqopt->info[type]; 174 struct qtree_mem_dqinfo *qinfo = info->dqi_priv; 175 ssize_t size; 176 177 down_write(&dqopt->dqio_sem); 178 spin_lock(&dq_data_lock); 179 info->dqi_flags &= ~DQF_INFO_DIRTY; 180 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace); 181 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace); 182 /* No flags currently supported */ 183 dinfo.dqi_flags = cpu_to_le32(0); 184 spin_unlock(&dq_data_lock); 185 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks); 186 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk); 187 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry); 188 size = sb->s_op->quota_write(sb, type, (char *)&dinfo, 189 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); 190 up_write(&dqopt->dqio_sem); 191 if (size != sizeof(struct v2_disk_dqinfo)) { 192 quota_error(sb, "Can't write info structure"); 193 return -1; 194 } 195 return 0; 196 } 197 198 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp) 199 { 200 struct v2r0_disk_dqblk *d = dp, empty; 201 struct mem_dqblk *m = &dquot->dq_dqb; 202 203 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit); 204 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit); 205 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes); 206 m->dqb_itime = le64_to_cpu(d->dqb_itime); 207 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit)); 208 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit)); 209 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 210 m->dqb_btime = le64_to_cpu(d->dqb_btime); 211 /* We need to escape back all-zero structure */ 212 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk)); 213 empty.dqb_itime = cpu_to_le64(1); 214 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk))) 215 m->dqb_itime = 0; 216 } 217 218 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot) 219 { 220 struct v2r0_disk_dqblk *d = dp; 221 struct mem_dqblk *m = &dquot->dq_dqb; 222 struct qtree_mem_dqinfo *info = 223 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 224 225 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit); 226 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit); 227 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes); 228 d->dqb_itime = cpu_to_le64(m->dqb_itime); 229 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit)); 230 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit)); 231 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 232 d->dqb_btime = cpu_to_le64(m->dqb_btime); 233 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 234 if (qtree_entry_unused(info, dp)) 235 d->dqb_itime = cpu_to_le64(1); 236 } 237 238 static int v2r0_is_id(void *dp, struct dquot *dquot) 239 { 240 struct v2r0_disk_dqblk *d = dp; 241 struct qtree_mem_dqinfo *info = 242 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 243 244 if (qtree_entry_unused(info, dp)) 245 return 0; 246 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 247 le32_to_cpu(d->dqb_id)), 248 dquot->dq_id); 249 } 250 251 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp) 252 { 253 struct v2r1_disk_dqblk *d = dp, empty; 254 struct mem_dqblk *m = &dquot->dq_dqb; 255 256 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit); 257 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit); 258 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes); 259 m->dqb_itime = le64_to_cpu(d->dqb_itime); 260 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit)); 261 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit)); 262 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 263 m->dqb_btime = le64_to_cpu(d->dqb_btime); 264 /* We need to escape back all-zero structure */ 265 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk)); 266 empty.dqb_itime = cpu_to_le64(1); 267 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk))) 268 m->dqb_itime = 0; 269 } 270 271 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot) 272 { 273 struct v2r1_disk_dqblk *d = dp; 274 struct mem_dqblk *m = &dquot->dq_dqb; 275 struct qtree_mem_dqinfo *info = 276 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 277 278 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit); 279 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit); 280 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes); 281 d->dqb_itime = cpu_to_le64(m->dqb_itime); 282 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit)); 283 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit)); 284 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 285 d->dqb_btime = cpu_to_le64(m->dqb_btime); 286 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 287 if (qtree_entry_unused(info, dp)) 288 d->dqb_itime = cpu_to_le64(1); 289 } 290 291 static int v2r1_is_id(void *dp, struct dquot *dquot) 292 { 293 struct v2r1_disk_dqblk *d = dp; 294 struct qtree_mem_dqinfo *info = 295 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 296 297 if (qtree_entry_unused(info, dp)) 298 return 0; 299 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 300 le32_to_cpu(d->dqb_id)), 301 dquot->dq_id); 302 } 303 304 static int v2_read_dquot(struct dquot *dquot) 305 { 306 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 307 int ret; 308 309 down_read(&dqopt->dqio_sem); 310 ret = qtree_read_dquot( 311 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 312 dquot); 313 up_read(&dqopt->dqio_sem); 314 return ret; 315 } 316 317 static int v2_write_dquot(struct dquot *dquot) 318 { 319 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 320 int ret; 321 bool alloc = false; 322 323 /* 324 * If space for dquot is already allocated, we don't need any 325 * protection as we'll only overwrite the place of dquot. We are 326 * still protected by concurrent writes of the same dquot by 327 * dquot->dq_lock. 328 */ 329 if (!dquot->dq_off) { 330 alloc = true; 331 down_write(&dqopt->dqio_sem); 332 } else { 333 down_read(&dqopt->dqio_sem); 334 } 335 ret = qtree_write_dquot( 336 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 337 dquot); 338 if (alloc) 339 up_write(&dqopt->dqio_sem); 340 else 341 up_read(&dqopt->dqio_sem); 342 return ret; 343 } 344 345 static int v2_release_dquot(struct dquot *dquot) 346 { 347 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 348 int ret; 349 350 down_write(&dqopt->dqio_sem); 351 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot); 352 up_write(&dqopt->dqio_sem); 353 354 return ret; 355 } 356 357 static int v2_free_file_info(struct super_block *sb, int type) 358 { 359 kfree(sb_dqinfo(sb, type)->dqi_priv); 360 return 0; 361 } 362 363 static int v2_get_next_id(struct super_block *sb, struct kqid *qid) 364 { 365 struct quota_info *dqopt = sb_dqopt(sb); 366 int ret; 367 368 down_read(&dqopt->dqio_sem); 369 ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid); 370 up_read(&dqopt->dqio_sem); 371 return ret; 372 } 373 374 static const struct quota_format_ops v2_format_ops = { 375 .check_quota_file = v2_check_quota_file, 376 .read_file_info = v2_read_file_info, 377 .write_file_info = v2_write_file_info, 378 .free_file_info = v2_free_file_info, 379 .read_dqblk = v2_read_dquot, 380 .commit_dqblk = v2_write_dquot, 381 .release_dqblk = v2_release_dquot, 382 .get_next_id = v2_get_next_id, 383 }; 384 385 static struct quota_format_type v2r0_quota_format = { 386 .qf_fmt_id = QFMT_VFS_V0, 387 .qf_ops = &v2_format_ops, 388 .qf_owner = THIS_MODULE 389 }; 390 391 static struct quota_format_type v2r1_quota_format = { 392 .qf_fmt_id = QFMT_VFS_V1, 393 .qf_ops = &v2_format_ops, 394 .qf_owner = THIS_MODULE 395 }; 396 397 static int __init init_v2_quota_format(void) 398 { 399 int ret; 400 401 ret = register_quota_format(&v2r0_quota_format); 402 if (ret) 403 return ret; 404 return register_quota_format(&v2r1_quota_format); 405 } 406 407 static void __exit exit_v2_quota_format(void) 408 { 409 unregister_quota_format(&v2r0_quota_format); 410 unregister_quota_format(&v2r1_quota_format); 411 } 412 413 module_init(init_v2_quota_format); 414 module_exit(exit_v2_quota_format); 415