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