fs/quota/quota_v2.c

   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
  47 static inline qsize_t v2_stoqb(qsize_t space)
  48 {
  49         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  50 }
  51
  52 static inline qsize_t v2_qbtos(qsize_t blocks)
  53 {
  54         return blocks << QUOTABLOCK_BITS;
  55 }
  56
  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 */
  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 */
  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_blocks) {
 172                 quota_error(sb, "Free block number too big (%u >= %u).",
 173                             qinfo->dqi_free_blk, qinfo->dqi_blocks);
 174                 goto out_free;
 175         }
 176         if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
 177                 quota_error(sb, "Block with free entry too big (%u >= %u).",
 178                             qinfo->dqi_free_entry, qinfo->dqi_blocks);
 179                 goto out_free;
 180         }
 181         ret = 0;
 182 out_free:
 183         if (ret) {
 184                 kfree(info->dqi_priv);
 185                 info->dqi_priv = NULL;
 186         }
 187 out:
 188         memalloc_nofs_restore(memalloc);
 189         up_read(&dqopt->dqio_sem);
 190         return ret;
 191 }
 192
 193 /* Write information header to quota file */
 194 static int v2_write_file_info(struct super_block *sb, int type)
 195 {
 196         struct v2_disk_dqinfo dinfo;
 197         struct quota_info *dqopt = sb_dqopt(sb);
 198         struct mem_dqinfo *info = &dqopt->info[type];
 199         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 200         ssize_t size;
 201         unsigned int memalloc;
 202
 203         down_write(&dqopt->dqio_sem);
 204         memalloc = memalloc_nofs_save();
 205         spin_lock(&dq_data_lock);
 206         info->dqi_flags &= ~DQF_INFO_DIRTY;
 207         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 208         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 209         /* No flags currently supported */
 210         dinfo.dqi_flags = cpu_to_le32(0);
 211         spin_unlock(&dq_data_lock);
 212         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 213         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 214         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 215         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 216                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 217         memalloc_nofs_restore(memalloc);
 218         up_write(&dqopt->dqio_sem);
 219         if (size != sizeof(struct v2_disk_dqinfo)) {
 220                 quota_error(sb, "Can't write info structure");
 221                 return size < 0 ? size : -EIO;
 222         }
 223         return 0;
 224 }
 225
 226 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 227 {
 228         struct v2r0_disk_dqblk *d = dp, empty;
 229         struct mem_dqblk *m = &dquot->dq_dqb;
 230
 231         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 232         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 233         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 234         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 235         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 236         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 237         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 238         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 239         /* We need to escape back all-zero structure */
 240         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 241         empty.dqb_itime = cpu_to_le64(1);
 242         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 243                 m->dqb_itime = 0;
 244 }
 245
 246 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 247 {
 248         struct v2r0_disk_dqblk *d = dp;
 249         struct mem_dqblk *m = &dquot->dq_dqb;
 250         struct qtree_mem_dqinfo *info =
 251                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 252
 253         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 254         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 255         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 256         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 257         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 258         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 259         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 260         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 261         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 262         if (qtree_entry_unused(info, dp))
 263                 d->dqb_itime = cpu_to_le64(1);
 264 }
 265
 266 static int v2r0_is_id(void *dp, struct dquot *dquot)
 267 {
 268         struct v2r0_disk_dqblk *d = dp;
 269         struct qtree_mem_dqinfo *info =
 270                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 271
 272         if (qtree_entry_unused(info, dp))
 273                 return 0;
 274         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 275                                 le32_to_cpu(d->dqb_id)),
 276                       dquot->dq_id);
 277 }
 278
 279 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 280 {
 281         struct v2r1_disk_dqblk *d = dp, empty;
 282         struct mem_dqblk *m = &dquot->dq_dqb;
 283
 284         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 285         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 286         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 287         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 288         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 289         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 290         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 291         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 292         /* We need to escape back all-zero structure */
 293         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 294         empty.dqb_itime = cpu_to_le64(1);
 295         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 296                 m->dqb_itime = 0;
 297 }
 298
 299 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 300 {
 301         struct v2r1_disk_dqblk *d = dp;
 302         struct mem_dqblk *m = &dquot->dq_dqb;
 303         struct qtree_mem_dqinfo *info =
 304                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 305
 306         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 307         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 308         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 309         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 310         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 311         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 312         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 313         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 314         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 315         d->dqb_pad = 0;
 316         if (qtree_entry_unused(info, dp))
 317                 d->dqb_itime = cpu_to_le64(1);
 318 }
 319
 320 static int v2r1_is_id(void *dp, struct dquot *dquot)
 321 {
 322         struct v2r1_disk_dqblk *d = dp;
 323         struct qtree_mem_dqinfo *info =
 324                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 325
 326         if (qtree_entry_unused(info, dp))
 327                 return 0;
 328         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 329                                 le32_to_cpu(d->dqb_id)),
 330                       dquot->dq_id);
 331 }
 332
 333 static int v2_read_dquot(struct dquot *dquot)
 334 {
 335         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 336         int ret;
 337         unsigned int memalloc;
 338
 339         down_read(&dqopt->dqio_sem);
 340         memalloc = memalloc_nofs_save();
 341         ret = qtree_read_dquot(
 342                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 343                         dquot);
 344         memalloc_nofs_restore(memalloc);
 345         up_read(&dqopt->dqio_sem);
 346         return ret;
 347 }
 348
 349 static int v2_write_dquot(struct dquot *dquot)
 350 {
 351         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 352         int ret;
 353         bool alloc = false;
 354         unsigned int memalloc;
 355
 356         /*
 357          * If space for dquot is already allocated, we don't need any
 358          * protection as we'll only overwrite the place of dquot. We are
 359          * still protected by concurrent writes of the same dquot by
 360          * dquot->dq_lock.
 361          */
 362         if (!dquot->dq_off) {
 363                 alloc = true;
 364                 down_write(&dqopt->dqio_sem);
 365         } else {
 366                 down_read(&dqopt->dqio_sem);
 367         }
 368         memalloc = memalloc_nofs_save();
 369         ret = qtree_write_dquot(
 370                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 371                         dquot);
 372         memalloc_nofs_restore(memalloc);
 373         if (alloc)
 374                 up_write(&dqopt->dqio_sem);
 375         else
 376                 up_read(&dqopt->dqio_sem);
 377         return ret;
 378 }
 379
 380 static int v2_release_dquot(struct dquot *dquot)
 381 {
 382         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 383         unsigned int memalloc;
 384         int ret;
 385
 386         down_write(&dqopt->dqio_sem);
 387         memalloc = memalloc_nofs_save();
 388         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 389         memalloc_nofs_restore(memalloc);
 390         up_write(&dqopt->dqio_sem);
 391
 392         return ret;
 393 }
 394
 395 static int v2_free_file_info(struct super_block *sb, int type)
 396 {
 397         kfree(sb_dqinfo(sb, type)->dqi_priv);
 398         return 0;
 399 }
 400
 401 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 402 {
 403         struct quota_info *dqopt = sb_dqopt(sb);
 404         unsigned int memalloc;
 405         int ret;
 406
 407         down_read(&dqopt->dqio_sem);
 408         memalloc = memalloc_nofs_save();
 409         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 410         memalloc_nofs_restore(memalloc);
 411         up_read(&dqopt->dqio_sem);
 412         return ret;
 413 }
 414
 415 static const struct quota_format_ops v2_format_ops = {
 416         .check_quota_file       = v2_check_quota_file,
 417         .read_file_info         = v2_read_file_info,
 418         .write_file_info        = v2_write_file_info,
 419         .free_file_info         = v2_free_file_info,
 420         .read_dqblk             = v2_read_dquot,
 421         .commit_dqblk           = v2_write_dquot,
 422         .release_dqblk          = v2_release_dquot,
 423         .get_next_id            = v2_get_next_id,
 424 };
 425
 426 static struct quota_format_type v2r0_quota_format = {
 427         .qf_fmt_id      = QFMT_VFS_V0,
 428         .qf_ops         = &v2_format_ops,
 429         .qf_owner       = THIS_MODULE
 430 };
 431
 432 static struct quota_format_type v2r1_quota_format = {
 433         .qf_fmt_id      = QFMT_VFS_V1,
 434         .qf_ops         = &v2_format_ops,
 435         .qf_owner       = THIS_MODULE
 436 };
 437
 438 static int __init init_v2_quota_format(void)
 439 {
 440         int ret;
 441
 442         ret = register_quota_format(&v2r0_quota_format);
 443         if (ret)
 444                 return ret;
 445         return register_quota_format(&v2r1_quota_format);
 446 }
 447
 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);