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 = 0;
 161 out:
 162         up_read(&dqopt->dqio_sem);
 163         return ret;
 164 }
 165
 166 /* Write information header to quota file */
 167 static int v2_write_file_info(struct super_block *sb, int type)
 168 {
 169         struct v2_disk_dqinfo dinfo;
 170         struct quota_info *dqopt = sb_dqopt(sb);
 171         struct mem_dqinfo *info = &dqopt->info[type];
 172         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 173         ssize_t size;
 174
 175         down_write(&dqopt->dqio_sem);
 176         spin_lock(&dq_data_lock);
 177         info->dqi_flags &= ~DQF_INFO_DIRTY;
 178         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 179         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 180         /* No flags currently supported */
 181         dinfo.dqi_flags = cpu_to_le32(0);
 182         spin_unlock(&dq_data_lock);
 183         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 184         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 185         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 186         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 187                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 188         up_write(&dqopt->dqio_sem);
 189         if (size != sizeof(struct v2_disk_dqinfo)) {
 190                 quota_error(sb, "Can't write info structure");
 191                 return -1;
 192         }
 193         return 0;
 194 }
 195
 196 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 197 {
 198         struct v2r0_disk_dqblk *d = dp, empty;
 199         struct mem_dqblk *m = &dquot->dq_dqb;
 200
 201         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 202         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 203         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 204         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 205         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 206         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 207         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 208         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 209         /* We need to escape back all-zero structure */
 210         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 211         empty.dqb_itime = cpu_to_le64(1);
 212         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 213                 m->dqb_itime = 0;
 214 }
 215
 216 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 217 {
 218         struct v2r0_disk_dqblk *d = dp;
 219         struct mem_dqblk *m = &dquot->dq_dqb;
 220         struct qtree_mem_dqinfo *info =
 221                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 222
 223         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 224         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 225         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 226         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 227         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 228         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 229         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 230         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 231         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 232         if (qtree_entry_unused(info, dp))
 233                 d->dqb_itime = cpu_to_le64(1);
 234 }
 235
 236 static int v2r0_is_id(void *dp, struct dquot *dquot)
 237 {
 238         struct v2r0_disk_dqblk *d = dp;
 239         struct qtree_mem_dqinfo *info =
 240                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 241
 242         if (qtree_entry_unused(info, dp))
 243                 return 0;
 244         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 245                                 le32_to_cpu(d->dqb_id)),
 246                       dquot->dq_id);
 247 }
 248
 249 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 250 {
 251         struct v2r1_disk_dqblk *d = dp, empty;
 252         struct mem_dqblk *m = &dquot->dq_dqb;
 253
 254         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 255         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 256         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 257         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 258         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 259         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 260         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 261         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 262         /* We need to escape back all-zero structure */
 263         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 264         empty.dqb_itime = cpu_to_le64(1);
 265         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 266                 m->dqb_itime = 0;
 267 }
 268
 269 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 270 {
 271         struct v2r1_disk_dqblk *d = dp;
 272         struct mem_dqblk *m = &dquot->dq_dqb;
 273         struct qtree_mem_dqinfo *info =
 274                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 275
 276         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 277         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 278         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 279         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 280         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 281         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 282         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 283         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 284         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 285         if (qtree_entry_unused(info, dp))
 286                 d->dqb_itime = cpu_to_le64(1);
 287 }
 288
 289 static int v2r1_is_id(void *dp, struct dquot *dquot)
 290 {
 291         struct v2r1_disk_dqblk *d = dp;
 292         struct qtree_mem_dqinfo *info =
 293                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 294
 295         if (qtree_entry_unused(info, dp))
 296                 return 0;
 297         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 298                                 le32_to_cpu(d->dqb_id)),
 299                       dquot->dq_id);
 300 }
 301
 302 static int v2_read_dquot(struct dquot *dquot)
 303 {
 304         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 305         int ret;
 306
 307         down_read(&dqopt->dqio_sem);
 308         ret = qtree_read_dquot(
 309                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 310                         dquot);
 311         up_read(&dqopt->dqio_sem);
 312         return ret;
 313 }
 314
 315 static int v2_write_dquot(struct dquot *dquot)
 316 {
 317         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 318         int ret;
 319         bool alloc = false;
 320
 321         /*
 322          * If space for dquot is already allocated, we don't need any
 323          * protection as we'll only overwrite the place of dquot. We are
 324          * still protected by concurrent writes of the same dquot by
 325          * dquot->dq_lock.
 326          */
 327         if (!dquot->dq_off) {
 328                 alloc = true;
 329                 down_write(&dqopt->dqio_sem);
 330         } else {
 331                 down_read(&dqopt->dqio_sem);
 332         }
 333         ret = qtree_write_dquot(
 334                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 335                         dquot);
 336         if (alloc)
 337                 up_write(&dqopt->dqio_sem);
 338         else
 339                 up_read(&dqopt->dqio_sem);
 340         return ret;
 341 }
 342
 343 static int v2_release_dquot(struct dquot *dquot)
 344 {
 345         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 346         int ret;
 347
 348         down_write(&dqopt->dqio_sem);
 349         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 350         up_write(&dqopt->dqio_sem);
 351
 352         return ret;
 353 }
 354
 355 static int v2_free_file_info(struct super_block *sb, int type)
 356 {
 357         kfree(sb_dqinfo(sb, type)->dqi_priv);
 358         return 0;
 359 }
 360
 361 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 362 {
 363         struct quota_info *dqopt = sb_dqopt(sb);
 364         int ret;
 365
 366         down_read(&dqopt->dqio_sem);
 367         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 368         up_read(&dqopt->dqio_sem);
 369         return ret;
 370 }
 371
 372 static const struct quota_format_ops v2_format_ops = {
 373         .check_quota_file       = v2_check_quota_file,
 374         .read_file_info         = v2_read_file_info,
 375         .write_file_info        = v2_write_file_info,
 376         .free_file_info         = v2_free_file_info,
 377         .read_dqblk             = v2_read_dquot,
 378         .commit_dqblk           = v2_write_dquot,
 379         .release_dqblk          = v2_release_dquot,
 380         .get_next_id            = v2_get_next_id,
 381 };
 382
 383 static struct quota_format_type v2r0_quota_format = {
 384         .qf_fmt_id      = QFMT_VFS_V0,
 385         .qf_ops         = &v2_format_ops,
 386         .qf_owner       = THIS_MODULE
 387 };
 388
 389 static struct quota_format_type v2r1_quota_format = {
 390         .qf_fmt_id      = QFMT_VFS_V1,
 391         .qf_ops         = &v2_format_ops,
 392         .qf_owner       = THIS_MODULE
 393 };
 394
 395 static int __init init_v2_quota_format(void)
 396 {
 397         int ret;
 398
 399         ret = register_quota_format(&v2r0_quota_format);
 400         if (ret)
 401                 return ret;
 402         return register_quota_format(&v2r1_quota_format);
 403 }
 404
 405 static void __exit exit_v2_quota_format(void)
 406 {
 407         unregister_quota_format(&v2r0_quota_format);
 408         unregister_quota_format(&v2r1_quota_format);
 409 }
 410
 411 module_init(init_v2_quota_format);
 412 module_exit(exit_v2_quota_format);