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/kernel.h> 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/quotaops.h> 14 15 #include <asm/byteorder.h> 16 17 #include "quota_tree.h" 18 #include "quotaio_v2.h" 19 20 MODULE_AUTHOR("Jan Kara"); 21 MODULE_DESCRIPTION("Quota format v2 support"); 22 MODULE_LICENSE("GPL"); 23 24 #define __QUOTA_V2_PARANOIA 25 26 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot); 27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp); 28 static int v2r0_is_id(void *dp, struct dquot *dquot); 29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot); 30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp); 31 static int v2r1_is_id(void *dp, struct dquot *dquot); 32 33 static const struct qtree_fmt_operations v2r0_qtree_ops = { 34 .mem2disk_dqblk = v2r0_mem2diskdqb, 35 .disk2mem_dqblk = v2r0_disk2memdqb, 36 .is_id = v2r0_is_id, 37 }; 38 39 static const struct qtree_fmt_operations v2r1_qtree_ops = { 40 .mem2disk_dqblk = v2r1_mem2diskdqb, 41 .disk2mem_dqblk = v2r1_disk2memdqb, 42 .is_id = v2r1_is_id, 43 }; 44 45 #define QUOTABLOCK_BITS 10 46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS) 47 48 static inline qsize_t v2_stoqb(qsize_t space) 49 { 50 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS; 51 } 52 53 static inline qsize_t v2_qbtos(qsize_t blocks) 54 { 55 return blocks << QUOTABLOCK_BITS; 56 } 57 58 static int v2_read_header(struct super_block *sb, int type, 59 struct v2_disk_dqheader *dqhead) 60 { 61 ssize_t size; 62 63 size = sb->s_op->quota_read(sb, type, (char *)dqhead, 64 sizeof(struct v2_disk_dqheader), 0); 65 if (size != sizeof(struct v2_disk_dqheader)) { 66 quota_error(sb, "Failed header read: expected=%zd got=%zd", 67 sizeof(struct v2_disk_dqheader), size); 68 if (size < 0) 69 return size; 70 return -EIO; 71 } 72 return 0; 73 } 74 75 /* Check whether given file is really vfsv0 quotafile */ 76 static int v2_check_quota_file(struct super_block *sb, int type) 77 { 78 struct v2_disk_dqheader dqhead; 79 static const uint quota_magics[] = V2_INITQMAGICS; 80 static const uint quota_versions[] = V2_INITQVERSIONS; 81 82 if (v2_read_header(sb, type, &dqhead)) 83 return 0; 84 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] || 85 le32_to_cpu(dqhead.dqh_version) > quota_versions[type]) 86 return 0; 87 return 1; 88 } 89 90 /* Read information header from quota file */ 91 static int v2_read_file_info(struct super_block *sb, int type) 92 { 93 struct v2_disk_dqinfo dinfo; 94 struct v2_disk_dqheader dqhead; 95 struct quota_info *dqopt = sb_dqopt(sb); 96 struct mem_dqinfo *info = &dqopt->info[type]; 97 struct qtree_mem_dqinfo *qinfo; 98 ssize_t size; 99 unsigned int version; 100 int ret; 101 102 down_read(&dqopt->dqio_sem); 103 ret = v2_read_header(sb, type, &dqhead); 104 if (ret < 0) 105 goto out; 106 version = le32_to_cpu(dqhead.dqh_version); 107 if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) || 108 (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) { 109 ret = -EINVAL; 110 goto out; 111 } 112 113 size = sb->s_op->quota_read(sb, type, (char *)&dinfo, 114 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); 115 if (size != sizeof(struct v2_disk_dqinfo)) { 116 quota_error(sb, "Can't read info structure"); 117 if (size < 0) 118 ret = size; 119 else 120 ret = -EIO; 121 goto out; 122 } 123 info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS); 124 if (!info->dqi_priv) { 125 ret = -ENOMEM; 126 goto out; 127 } 128 qinfo = info->dqi_priv; 129 if (version == 0) { 130 /* limits are stored as unsigned 32-bit data */ 131 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS; 132 info->dqi_max_ino_limit = 0xffffffff; 133 } else { 134 /* 135 * Used space is stored as unsigned 64-bit value in bytes but 136 * quota core supports only signed 64-bit values so use that 137 * as a limit 138 */ 139 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */ 140 info->dqi_max_ino_limit = 0x7fffffffffffffffLL; 141 } 142 info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace); 143 info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace); 144 /* No flags currently supported */ 145 info->dqi_flags = 0; 146 qinfo->dqi_sb = sb; 147 qinfo->dqi_type = type; 148 qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks); 149 qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk); 150 qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry); 151 qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS; 152 qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS; 153 qinfo->dqi_qtree_depth = qtree_depth(qinfo); 154 if (version == 0) { 155 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk); 156 qinfo->dqi_ops = &v2r0_qtree_ops; 157 } else { 158 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk); 159 qinfo->dqi_ops = &v2r1_qtree_ops; 160 } 161 ret = 0; 162 out: 163 up_read(&dqopt->dqio_sem); 164 return ret; 165 } 166 167 /* Write information header to quota file */ 168 static int v2_write_file_info(struct super_block *sb, int type) 169 { 170 struct v2_disk_dqinfo dinfo; 171 struct quota_info *dqopt = sb_dqopt(sb); 172 struct mem_dqinfo *info = &dqopt->info[type]; 173 struct qtree_mem_dqinfo *qinfo = info->dqi_priv; 174 ssize_t size; 175 176 down_write(&dqopt->dqio_sem); 177 spin_lock(&dq_data_lock); 178 info->dqi_flags &= ~DQF_INFO_DIRTY; 179 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace); 180 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace); 181 /* No flags currently supported */ 182 dinfo.dqi_flags = cpu_to_le32(0); 183 spin_unlock(&dq_data_lock); 184 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks); 185 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk); 186 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry); 187 size = sb->s_op->quota_write(sb, type, (char *)&dinfo, 188 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); 189 up_write(&dqopt->dqio_sem); 190 if (size != sizeof(struct v2_disk_dqinfo)) { 191 quota_error(sb, "Can't write info structure"); 192 return -1; 193 } 194 return 0; 195 } 196 197 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp) 198 { 199 struct v2r0_disk_dqblk *d = dp, empty; 200 struct mem_dqblk *m = &dquot->dq_dqb; 201 202 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit); 203 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit); 204 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes); 205 m->dqb_itime = le64_to_cpu(d->dqb_itime); 206 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit)); 207 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit)); 208 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 209 m->dqb_btime = le64_to_cpu(d->dqb_btime); 210 /* We need to escape back all-zero structure */ 211 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk)); 212 empty.dqb_itime = cpu_to_le64(1); 213 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk))) 214 m->dqb_itime = 0; 215 } 216 217 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot) 218 { 219 struct v2r0_disk_dqblk *d = dp; 220 struct mem_dqblk *m = &dquot->dq_dqb; 221 struct qtree_mem_dqinfo *info = 222 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 223 224 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit); 225 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit); 226 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes); 227 d->dqb_itime = cpu_to_le64(m->dqb_itime); 228 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit)); 229 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit)); 230 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 231 d->dqb_btime = cpu_to_le64(m->dqb_btime); 232 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 233 if (qtree_entry_unused(info, dp)) 234 d->dqb_itime = cpu_to_le64(1); 235 } 236 237 static int v2r0_is_id(void *dp, struct dquot *dquot) 238 { 239 struct v2r0_disk_dqblk *d = dp; 240 struct qtree_mem_dqinfo *info = 241 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 242 243 if (qtree_entry_unused(info, dp)) 244 return 0; 245 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 246 le32_to_cpu(d->dqb_id)), 247 dquot->dq_id); 248 } 249 250 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp) 251 { 252 struct v2r1_disk_dqblk *d = dp, empty; 253 struct mem_dqblk *m = &dquot->dq_dqb; 254 255 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit); 256 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit); 257 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes); 258 m->dqb_itime = le64_to_cpu(d->dqb_itime); 259 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit)); 260 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit)); 261 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 262 m->dqb_btime = le64_to_cpu(d->dqb_btime); 263 /* We need to escape back all-zero structure */ 264 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk)); 265 empty.dqb_itime = cpu_to_le64(1); 266 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk))) 267 m->dqb_itime = 0; 268 } 269 270 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot) 271 { 272 struct v2r1_disk_dqblk *d = dp; 273 struct mem_dqblk *m = &dquot->dq_dqb; 274 struct qtree_mem_dqinfo *info = 275 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 276 277 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit); 278 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit); 279 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes); 280 d->dqb_itime = cpu_to_le64(m->dqb_itime); 281 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit)); 282 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit)); 283 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 284 d->dqb_btime = cpu_to_le64(m->dqb_btime); 285 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 286 if (qtree_entry_unused(info, dp)) 287 d->dqb_itime = cpu_to_le64(1); 288 } 289 290 static int v2r1_is_id(void *dp, struct dquot *dquot) 291 { 292 struct v2r1_disk_dqblk *d = dp; 293 struct qtree_mem_dqinfo *info = 294 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 295 296 if (qtree_entry_unused(info, dp)) 297 return 0; 298 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 299 le32_to_cpu(d->dqb_id)), 300 dquot->dq_id); 301 } 302 303 static int v2_read_dquot(struct dquot *dquot) 304 { 305 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 306 int ret; 307 308 down_read(&dqopt->dqio_sem); 309 ret = qtree_read_dquot( 310 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 311 dquot); 312 up_read(&dqopt->dqio_sem); 313 return ret; 314 } 315 316 static int v2_write_dquot(struct dquot *dquot) 317 { 318 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 319 int ret; 320 bool alloc = false; 321 322 /* 323 * If space for dquot is already allocated, we don't need any 324 * protection as we'll only overwrite the place of dquot. We are 325 * still protected by concurrent writes of the same dquot by 326 * dquot->dq_lock. 327 */ 328 if (!dquot->dq_off) { 329 alloc = true; 330 down_write(&dqopt->dqio_sem); 331 } else { 332 down_read(&dqopt->dqio_sem); 333 } 334 ret = qtree_write_dquot( 335 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 336 dquot); 337 if (alloc) 338 up_write(&dqopt->dqio_sem); 339 else 340 up_read(&dqopt->dqio_sem); 341 return ret; 342 } 343 344 static int v2_release_dquot(struct dquot *dquot) 345 { 346 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 347 int ret; 348 349 down_write(&dqopt->dqio_sem); 350 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot); 351 up_write(&dqopt->dqio_sem); 352 353 return ret; 354 } 355 356 static int v2_free_file_info(struct super_block *sb, int type) 357 { 358 kfree(sb_dqinfo(sb, type)->dqi_priv); 359 return 0; 360 } 361 362 static int v2_get_next_id(struct super_block *sb, struct kqid *qid) 363 { 364 struct quota_info *dqopt = sb_dqopt(sb); 365 int ret; 366 367 down_read(&dqopt->dqio_sem); 368 ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid); 369 up_read(&dqopt->dqio_sem); 370 return ret; 371 } 372 373 static const struct quota_format_ops v2_format_ops = { 374 .check_quota_file = v2_check_quota_file, 375 .read_file_info = v2_read_file_info, 376 .write_file_info = v2_write_file_info, 377 .free_file_info = v2_free_file_info, 378 .read_dqblk = v2_read_dquot, 379 .commit_dqblk = v2_write_dquot, 380 .release_dqblk = v2_release_dquot, 381 .get_next_id = v2_get_next_id, 382 }; 383 384 static struct quota_format_type v2r0_quota_format = { 385 .qf_fmt_id = QFMT_VFS_V0, 386 .qf_ops = &v2_format_ops, 387 .qf_owner = THIS_MODULE 388 }; 389 390 static struct quota_format_type v2r1_quota_format = { 391 .qf_fmt_id = QFMT_VFS_V1, 392 .qf_ops = &v2_format_ops, 393 .qf_owner = THIS_MODULE 394 }; 395 396 static int __init init_v2_quota_format(void) 397 { 398 int ret; 399 400 ret = register_quota_format(&v2r0_quota_format); 401 if (ret) 402 return ret; 403 return register_quota_format(&v2r1_quota_format); 404 } 405 406 static void __exit exit_v2_quota_format(void) 407 { 408 unregister_quota_format(&v2r0_quota_format); 409 unregister_quota_format(&v2r1_quota_format); 410 } 411 412 module_init(init_v2_quota_format); 413 module_exit(exit_v2_quota_format); 414