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