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_free;
 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_free;
 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_free;
 178         }
 179         ret = 0;
 180 out_free:
 181         if (ret) {
 182                 kfree(info->dqi_priv);
 183                 info->dqi_priv = NULL;
 184         }
 185 out:
 186         up_read(&dqopt->dqio_sem);
 187         return ret;
 188 }
 189
 190 /* Write information header to quota file */
 191 static int v2_write_file_info(struct super_block *sb, int type)
 192 {
 193         struct v2_disk_dqinfo dinfo;
 194         struct quota_info *dqopt = sb_dqopt(sb);
 195         struct mem_dqinfo *info = &dqopt->info[type];
 196         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 197         ssize_t size;
 198
 199         down_write(&dqopt->dqio_sem);
 200         spin_lock(&dq_data_lock);
 201         info->dqi_flags &= ~DQF_INFO_DIRTY;
 202         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 203         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 204         /* No flags currently supported */
 205         dinfo.dqi_flags = cpu_to_le32(0);
 206         spin_unlock(&dq_data_lock);
 207         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 208         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 209         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 210         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 211                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 212         up_write(&dqopt->dqio_sem);
 213         if (size != sizeof(struct v2_disk_dqinfo)) {
 214                 quota_error(sb, "Can't write info structure");
 215                 return -1;
 216         }
 217         return 0;
 218 }
 219
 220 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 221 {
 222         struct v2r0_disk_dqblk *d = dp, empty;
 223         struct mem_dqblk *m = &dquot->dq_dqb;
 224
 225         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 226         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 227         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 228         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 229         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 230         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 231         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 232         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 233         /* We need to escape back all-zero structure */
 234         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 235         empty.dqb_itime = cpu_to_le64(1);
 236         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 237                 m->dqb_itime = 0;
 238 }
 239
 240 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 241 {
 242         struct v2r0_disk_dqblk *d = dp;
 243         struct mem_dqblk *m = &dquot->dq_dqb;
 244         struct qtree_mem_dqinfo *info =
 245                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 246
 247         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 248         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 249         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 250         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 251         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 252         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 253         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 254         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 255         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 256         if (qtree_entry_unused(info, dp))
 257                 d->dqb_itime = cpu_to_le64(1);
 258 }
 259
 260 static int v2r0_is_id(void *dp, struct dquot *dquot)
 261 {
 262         struct v2r0_disk_dqblk *d = dp;
 263         struct qtree_mem_dqinfo *info =
 264                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 265
 266         if (qtree_entry_unused(info, dp))
 267                 return 0;
 268         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 269                                 le32_to_cpu(d->dqb_id)),
 270                       dquot->dq_id);
 271 }
 272
 273 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 274 {
 275         struct v2r1_disk_dqblk *d = dp, empty;
 276         struct mem_dqblk *m = &dquot->dq_dqb;
 277
 278         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 279         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 280         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 281         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 282         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 283         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 284         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 285         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 286         /* We need to escape back all-zero structure */
 287         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 288         empty.dqb_itime = cpu_to_le64(1);
 289         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 290                 m->dqb_itime = 0;
 291 }
 292
 293 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 294 {
 295         struct v2r1_disk_dqblk *d = dp;
 296         struct mem_dqblk *m = &dquot->dq_dqb;
 297         struct qtree_mem_dqinfo *info =
 298                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 299
 300         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 301         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 302         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 303         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 304         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 305         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 306         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 307         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 308         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 309         d->dqb_pad = 0;
 310         if (qtree_entry_unused(info, dp))
 311                 d->dqb_itime = cpu_to_le64(1);
 312 }
 313
 314 static int v2r1_is_id(void *dp, struct dquot *dquot)
 315 {
 316         struct v2r1_disk_dqblk *d = dp;
 317         struct qtree_mem_dqinfo *info =
 318                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 319
 320         if (qtree_entry_unused(info, dp))
 321                 return 0;
 322         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 323                                 le32_to_cpu(d->dqb_id)),
 324                       dquot->dq_id);
 325 }
 326
 327 static int v2_read_dquot(struct dquot *dquot)
 328 {
 329         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 330         int ret;
 331
 332         down_read(&dqopt->dqio_sem);
 333         ret = qtree_read_dquot(
 334                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 335                         dquot);
 336         up_read(&dqopt->dqio_sem);
 337         return ret;
 338 }
 339
 340 static int v2_write_dquot(struct dquot *dquot)
 341 {
 342         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 343         int ret;
 344         bool alloc = false;
 345
 346         /*
 347          * If space for dquot is already allocated, we don't need any
 348          * protection as we'll only overwrite the place of dquot. We are
 349          * still protected by concurrent writes of the same dquot by
 350          * dquot->dq_lock.
 351          */
 352         if (!dquot->dq_off) {
 353                 alloc = true;
 354                 down_write(&dqopt->dqio_sem);
 355         } else {
 356                 down_read(&dqopt->dqio_sem);
 357         }
 358         ret = qtree_write_dquot(
 359                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 360                         dquot);
 361         if (alloc)
 362                 up_write(&dqopt->dqio_sem);
 363         else
 364                 up_read(&dqopt->dqio_sem);
 365         return ret;
 366 }
 367
 368 static int v2_release_dquot(struct dquot *dquot)
 369 {
 370         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 371         int ret;
 372
 373         down_write(&dqopt->dqio_sem);
 374         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 375         up_write(&dqopt->dqio_sem);
 376
 377         return ret;
 378 }
 379
 380 static int v2_free_file_info(struct super_block *sb, int type)
 381 {
 382         kfree(sb_dqinfo(sb, type)->dqi_priv);
 383         return 0;
 384 }
 385
 386 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 387 {
 388         struct quota_info *dqopt = sb_dqopt(sb);
 389         int ret;
 390
 391         down_read(&dqopt->dqio_sem);
 392         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 393         up_read(&dqopt->dqio_sem);
 394         return ret;
 395 }
 396
 397 static const struct quota_format_ops v2_format_ops = {
 398         .check_quota_file       = v2_check_quota_file,
 399         .read_file_info         = v2_read_file_info,
 400         .write_file_info        = v2_write_file_info,
 401         .free_file_info         = v2_free_file_info,
 402         .read_dqblk             = v2_read_dquot,
 403         .commit_dqblk           = v2_write_dquot,
 404         .release_dqblk          = v2_release_dquot,
 405         .get_next_id            = v2_get_next_id,
 406 };
 407
 408 static struct quota_format_type v2r0_quota_format = {
 409         .qf_fmt_id      = QFMT_VFS_V0,
 410         .qf_ops         = &v2_format_ops,
 411         .qf_owner       = THIS_MODULE
 412 };
 413
 414 static struct quota_format_type v2r1_quota_format = {
 415         .qf_fmt_id      = QFMT_VFS_V1,
 416         .qf_ops         = &v2_format_ops,
 417         .qf_owner       = THIS_MODULE
 418 };
 419
 420 static int __init init_v2_quota_format(void)
 421 {
 422         int ret;
 423
 424         ret = register_quota_format(&v2r0_quota_format);
 425         if (ret)
 426                 return ret;
 427         return register_quota_format(&v2r1_quota_format);
 428 }
 429
 430 static void __exit exit_v2_quota_format(void)
 431 {
 432         unregister_quota_format(&v2r0_quota_format);
 433         unregister_quota_format(&v2r1_quota_format);
 434 }
 435
 436 module_init(init_v2_quota_format);
 437 module_exit(exit_v2_quota_format);