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         int ret;
 100
 101         down_read(&dqopt->dqio_sem);
 102         ret = v2_read_header(sb, type, &dqhead);
 103         if (ret < 0)
 104                 goto out;
 105         version = le32_to_cpu(dqhead.dqh_version);
 106         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
 107             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
 108                 ret = -EINVAL;
 109                 goto out;
 110         }
 111
 112         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
 113                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 114         if (size != sizeof(struct v2_disk_dqinfo)) {
 115                 quota_error(sb, "Can't read info structure");
 116                 if (size < 0)
 117                         ret = size;
 118                 else
 119                         ret = -EIO;
 120                 goto out;
 121         }
 122         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
 123         if (!info->dqi_priv) {
 124                 ret = -ENOMEM;
 125                 goto out;
 126         }
 127         qinfo = info->dqi_priv;
 128         if (version == 0) {
 129                 /* limits are stored as unsigned 32-bit data */
 130                 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
 131                 info->dqi_max_ino_limit = 0xffffffff;
 132         } else {
 133                 /*
 134                  * Used space is stored as unsigned 64-bit value in bytes but
 135                  * quota core supports only signed 64-bit values so use that
 136                  * as a limit
 137                  */
 138                 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
 139                 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
 140         }
 141         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 142         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 143         /* No flags currently supported */
 144         info->dqi_flags = 0;
 145         qinfo->dqi_sb = sb;
 146         qinfo->dqi_type = type;
 147         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 148         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 149         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 150         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 151         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 152         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 153         if (version == 0) {
 154                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
 155                 qinfo->dqi_ops = &v2r0_qtree_ops;
 156         } else {
 157                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 158                 qinfo->dqi_ops = &v2r1_qtree_ops;
 159         }
 160         ret = -EUCLEAN;
 161         /* Some sanity checks of the read headers... */
 162         if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
 163             i_size_read(sb_dqopt(sb)->files[type])) {
 164                 quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
 165                     (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
 166                     i_size_read(sb_dqopt(sb)->files[type]));
 167                 goto out;
 168         }
 169         if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
 170                 quota_error(sb, "Free block number too big (%u >= %u).",
 171                             qinfo->dqi_free_blk, qinfo->dqi_blocks);
 172                 goto out;
 173         }
 174         if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
 175                 quota_error(sb, "Block with free entry too big (%u >= %u).",
 176                             qinfo->dqi_free_entry, qinfo->dqi_blocks);
 177                 goto out;
 178         }
 179         ret = 0;
 180 out:
 181         up_read(&dqopt->dqio_sem);
 182         return ret;
 183 }
 184
 185 /* Write information header to quota file */
 186 static int v2_write_file_info(struct super_block *sb, int type)
 187 {
 188         struct v2_disk_dqinfo dinfo;
 189         struct quota_info *dqopt = sb_dqopt(sb);
 190         struct mem_dqinfo *info = &dqopt->info[type];
 191         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 192         ssize_t size;
 193
 194         down_write(&dqopt->dqio_sem);
 195         spin_lock(&dq_data_lock);
 196         info->dqi_flags &= ~DQF_INFO_DIRTY;
 197         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 198         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 199         /* No flags currently supported */
 200         dinfo.dqi_flags = cpu_to_le32(0);
 201         spin_unlock(&dq_data_lock);
 202         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 203         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 204         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 205         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 206                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 207         up_write(&dqopt->dqio_sem);
 208         if (size != sizeof(struct v2_disk_dqinfo)) {
 209                 quota_error(sb, "Can't write info structure");
 210                 return -1;
 211         }
 212         return 0;
 213 }
 214
 215 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 216 {
 217         struct v2r0_disk_dqblk *d = dp, empty;
 218         struct mem_dqblk *m = &dquot->dq_dqb;
 219
 220         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 221         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 222         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 223         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 224         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 225         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 226         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 227         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 228         /* We need to escape back all-zero structure */
 229         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 230         empty.dqb_itime = cpu_to_le64(1);
 231         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 232                 m->dqb_itime = 0;
 233 }
 234
 235 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 236 {
 237         struct v2r0_disk_dqblk *d = dp;
 238         struct mem_dqblk *m = &dquot->dq_dqb;
 239         struct qtree_mem_dqinfo *info =
 240                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 241
 242         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 243         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 244         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 245         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 246         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 247         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 248         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 249         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 250         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 251         if (qtree_entry_unused(info, dp))
 252                 d->dqb_itime = cpu_to_le64(1);
 253 }
 254
 255 static int v2r0_is_id(void *dp, struct dquot *dquot)
 256 {
 257         struct v2r0_disk_dqblk *d = dp;
 258         struct qtree_mem_dqinfo *info =
 259                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 260
 261         if (qtree_entry_unused(info, dp))
 262                 return 0;
 263         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 264                                 le32_to_cpu(d->dqb_id)),
 265                       dquot->dq_id);
 266 }
 267
 268 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 269 {
 270         struct v2r1_disk_dqblk *d = dp, empty;
 271         struct mem_dqblk *m = &dquot->dq_dqb;
 272
 273         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 274         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 275         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 276         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 277         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 278         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 279         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 280         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 281         /* We need to escape back all-zero structure */
 282         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 283         empty.dqb_itime = cpu_to_le64(1);
 284         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 285                 m->dqb_itime = 0;
 286 }
 287
 288 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 289 {
 290         struct v2r1_disk_dqblk *d = dp;
 291         struct mem_dqblk *m = &dquot->dq_dqb;
 292         struct qtree_mem_dqinfo *info =
 293                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 294
 295         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 296         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 297         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 298         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 299         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 300         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 301         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 302         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 303         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 304         d->dqb_pad = 0;
 305         if (qtree_entry_unused(info, dp))
 306                 d->dqb_itime = cpu_to_le64(1);
 307 }
 308
 309 static int v2r1_is_id(void *dp, struct dquot *dquot)
 310 {
 311         struct v2r1_disk_dqblk *d = dp;
 312         struct qtree_mem_dqinfo *info =
 313                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 314
 315         if (qtree_entry_unused(info, dp))
 316                 return 0;
 317         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 318                                 le32_to_cpu(d->dqb_id)),
 319                       dquot->dq_id);
 320 }
 321
 322 static int v2_read_dquot(struct dquot *dquot)
 323 {
 324         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 325         int ret;
 326
 327         down_read(&dqopt->dqio_sem);
 328         ret = qtree_read_dquot(
 329                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 330                         dquot);
 331         up_read(&dqopt->dqio_sem);
 332         return ret;
 333 }
 334
 335 static int v2_write_dquot(struct dquot *dquot)
 336 {
 337         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 338         int ret;
 339         bool alloc = false;
 340
 341         /*
 342          * If space for dquot is already allocated, we don't need any
 343          * protection as we'll only overwrite the place of dquot. We are
 344          * still protected by concurrent writes of the same dquot by
 345          * dquot->dq_lock.
 346          */
 347         if (!dquot->dq_off) {
 348                 alloc = true;
 349                 down_write(&dqopt->dqio_sem);
 350         } else {
 351                 down_read(&dqopt->dqio_sem);
 352         }
 353         ret = qtree_write_dquot(
 354                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 355                         dquot);
 356         if (alloc)
 357                 up_write(&dqopt->dqio_sem);
 358         else
 359                 up_read(&dqopt->dqio_sem);
 360         return ret;
 361 }
 362
 363 static int v2_release_dquot(struct dquot *dquot)
 364 {
 365         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 366         int ret;
 367
 368         down_write(&dqopt->dqio_sem);
 369         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 370         up_write(&dqopt->dqio_sem);
 371
 372         return ret;
 373 }
 374
 375 static int v2_free_file_info(struct super_block *sb, int type)
 376 {
 377         kfree(sb_dqinfo(sb, type)->dqi_priv);
 378         return 0;
 379 }
 380
 381 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 382 {
 383         struct quota_info *dqopt = sb_dqopt(sb);
 384         int ret;
 385
 386         down_read(&dqopt->dqio_sem);
 387         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 388         up_read(&dqopt->dqio_sem);
 389         return ret;
 390 }
 391
 392 static const struct quota_format_ops v2_format_ops = {
 393         .check_quota_file       = v2_check_quota_file,
 394         .read_file_info         = v2_read_file_info,
 395         .write_file_info        = v2_write_file_info,
 396         .free_file_info         = v2_free_file_info,
 397         .read_dqblk             = v2_read_dquot,
 398         .commit_dqblk           = v2_write_dquot,
 399         .release_dqblk          = v2_release_dquot,
 400         .get_next_id            = v2_get_next_id,
 401 };
 402
 403 static struct quota_format_type v2r0_quota_format = {
 404         .qf_fmt_id      = QFMT_VFS_V0,
 405         .qf_ops         = &v2_format_ops,
 406         .qf_owner       = THIS_MODULE
 407 };
 408
 409 static struct quota_format_type v2r1_quota_format = {
 410         .qf_fmt_id      = QFMT_VFS_V1,
 411         .qf_ops         = &v2_format_ops,
 412         .qf_owner       = THIS_MODULE
 413 };
 414
 415 static int __init init_v2_quota_format(void)
 416 {
 417         int ret;
 418
 419         ret = register_quota_format(&v2r0_quota_format);
 420         if (ret)
 421                 return ret;
 422         return register_quota_format(&v2r1_quota_format);
 423 }
 424
 425 static void __exit exit_v2_quota_format(void)
 426 {
 427         unregister_quota_format(&v2r0_quota_format);
 428         unregister_quota_format(&v2r1_quota_format);
 429 }
 430
 431 module_init(init_v2_quota_format);
 432 module_exit(exit_v2_quota_format);