fs/quota/quota_v2.c

   1 /*
   2  *      vfsv0 quota IO operations on file
   3  */
   4
   5 #include <linux/errno.h>
   6 #include <linux/fs.h>
   7 #include <linux/mount.h>
   8 #include <linux/dqblk_v2.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/quotaops.h>
  14
  15 #include <asm/byteorder.h>
  16
  17 #include "quota_tree.h"
  18 #include "quotaio_v2.h"
  19
  20 MODULE_AUTHOR("Jan Kara");
  21 MODULE_DESCRIPTION("Quota format v2 support");
  22 MODULE_LICENSE("GPL");
  23
  24 #define __QUOTA_V2_PARANOIA
  25
  26 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
  27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
  28 static int v2r0_is_id(void *dp, struct dquot *dquot);
  29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
  30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
  31 static int v2r1_is_id(void *dp, struct dquot *dquot);
  32
  33 static const struct qtree_fmt_operations v2r0_qtree_ops = {
  34         .mem2disk_dqblk = v2r0_mem2diskdqb,
  35         .disk2mem_dqblk = v2r0_disk2memdqb,
  36         .is_id = v2r0_is_id,
  37 };
  38
  39 static const struct qtree_fmt_operations v2r1_qtree_ops = {
  40         .mem2disk_dqblk = v2r1_mem2diskdqb,
  41         .disk2mem_dqblk = v2r1_disk2memdqb,
  42         .is_id = v2r1_is_id,
  43 };
  44
  45 #define QUOTABLOCK_BITS 10
  46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
  47
  48 static inline qsize_t v2_stoqb(qsize_t space)
  49 {
  50         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  51 }
  52
  53 static inline qsize_t v2_qbtos(qsize_t blocks)
  54 {
  55         return blocks << QUOTABLOCK_BITS;
  56 }
  57
  58 static int v2_read_header(struct super_block *sb, int type,
  59                           struct v2_disk_dqheader *dqhead)
  60 {
  61         ssize_t size;
  62
  63         size = sb->s_op->quota_read(sb, type, (char *)dqhead,
  64                                     sizeof(struct v2_disk_dqheader), 0);
  65         if (size != sizeof(struct v2_disk_dqheader)) {
  66                 quota_error(sb, "Failed header read: expected=%zd got=%zd",
  67                             sizeof(struct v2_disk_dqheader), size);
  68                 if (size < 0)
  69                         return size;
  70                 return -EIO;
  71         }
  72         return 0;
  73 }
  74
  75 /* Check whether given file is really vfsv0 quotafile */
  76 static int v2_check_quota_file(struct super_block *sb, int type)
  77 {
  78         struct v2_disk_dqheader dqhead;
  79         static const uint quota_magics[] = V2_INITQMAGICS;
  80         static const uint quota_versions[] = V2_INITQVERSIONS;
  81
  82         if (v2_read_header(sb, type, &dqhead))
  83                 return 0;
  84         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
  85             le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
  86                 return 0;
  87         return 1;
  88 }
  89
  90 /* Read information header from quota file */
  91 static int v2_read_file_info(struct super_block *sb, int type)
  92 {
  93         struct v2_disk_dqinfo dinfo;
  94         struct v2_disk_dqheader dqhead;
  95         struct quota_info *dqopt = sb_dqopt(sb);
  96         struct mem_dqinfo *info = &dqopt->info[type];
  97         struct qtree_mem_dqinfo *qinfo;
  98         ssize_t size;
  99         unsigned int version;
 100         int ret;
 101
 102         down_read(&dqopt->dqio_sem);
 103         ret = v2_read_header(sb, type, &dqhead);
 104         if (ret < 0)
 105                 goto out;
 106         version = le32_to_cpu(dqhead.dqh_version);
 107         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
 108             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
 109                 ret = -EINVAL;
 110                 goto out;
 111         }
 112
 113         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
 114                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 115         if (size != sizeof(struct v2_disk_dqinfo)) {
 116                 quota_error(sb, "Can't read info structure");
 117                 if (size < 0)
 118                         ret = size;
 119                 else
 120                         ret = -EIO;
 121                 goto out;
 122         }
 123         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
 124         if (!info->dqi_priv) {
 125                 printk(KERN_WARNING
 126                        "Not enough memory for quota information structure.\n");
 127                 ret = -ENOMEM;
 128                 goto out;
 129         }
 130         qinfo = info->dqi_priv;
 131         if (version == 0) {
 132                 /* limits are stored as unsigned 32-bit data */
 133                 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
 134                 info->dqi_max_ino_limit = 0xffffffff;
 135         } else {
 136                 /*
 137                  * Used space is stored as unsigned 64-bit value in bytes but
 138                  * quota core supports only signed 64-bit values so use that
 139                  * as a limit
 140                  */
 141                 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
 142                 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
 143         }
 144         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 145         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 146         /* No flags currently supported */
 147         info->dqi_flags = 0;
 148         qinfo->dqi_sb = sb;
 149         qinfo->dqi_type = type;
 150         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 151         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 152         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 153         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 154         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 155         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 156         if (version == 0) {
 157                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
 158                 qinfo->dqi_ops = &v2r0_qtree_ops;
 159         } else {
 160                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 161                 qinfo->dqi_ops = &v2r1_qtree_ops;
 162         }
 163         ret = 0;
 164 out:
 165         up_read(&dqopt->dqio_sem);
 166         return ret;
 167 }
 168
 169 /* Write information header to quota file */
 170 static int v2_write_file_info(struct super_block *sb, int type)
 171 {
 172         struct v2_disk_dqinfo dinfo;
 173         struct quota_info *dqopt = sb_dqopt(sb);
 174         struct mem_dqinfo *info = &dqopt->info[type];
 175         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 176         ssize_t size;
 177
 178         down_write(&dqopt->dqio_sem);
 179         spin_lock(&dq_data_lock);
 180         info->dqi_flags &= ~DQF_INFO_DIRTY;
 181         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 182         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 183         /* No flags currently supported */
 184         dinfo.dqi_flags = cpu_to_le32(0);
 185         spin_unlock(&dq_data_lock);
 186         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 187         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 188         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 189         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 190                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 191         up_write(&dqopt->dqio_sem);
 192         if (size != sizeof(struct v2_disk_dqinfo)) {
 193                 quota_error(sb, "Can't write info structure");
 194                 return -1;
 195         }
 196         return 0;
 197 }
 198
 199 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 200 {
 201         struct v2r0_disk_dqblk *d = dp, empty;
 202         struct mem_dqblk *m = &dquot->dq_dqb;
 203
 204         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 205         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 206         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 207         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 208         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 209         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 210         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 211         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 212         /* We need to escape back all-zero structure */
 213         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 214         empty.dqb_itime = cpu_to_le64(1);
 215         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 216                 m->dqb_itime = 0;
 217 }
 218
 219 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 220 {
 221         struct v2r0_disk_dqblk *d = dp;
 222         struct mem_dqblk *m = &dquot->dq_dqb;
 223         struct qtree_mem_dqinfo *info =
 224                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 225
 226         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 227         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 228         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 229         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 230         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 231         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 232         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 233         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 234         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 235         if (qtree_entry_unused(info, dp))
 236                 d->dqb_itime = cpu_to_le64(1);
 237 }
 238
 239 static int v2r0_is_id(void *dp, struct dquot *dquot)
 240 {
 241         struct v2r0_disk_dqblk *d = dp;
 242         struct qtree_mem_dqinfo *info =
 243                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 244
 245         if (qtree_entry_unused(info, dp))
 246                 return 0;
 247         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 248                                 le32_to_cpu(d->dqb_id)),
 249                       dquot->dq_id);
 250 }
 251
 252 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 253 {
 254         struct v2r1_disk_dqblk *d = dp, empty;
 255         struct mem_dqblk *m = &dquot->dq_dqb;
 256
 257         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 258         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 259         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 260         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 261         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 262         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 263         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 264         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 265         /* We need to escape back all-zero structure */
 266         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 267         empty.dqb_itime = cpu_to_le64(1);
 268         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 269                 m->dqb_itime = 0;
 270 }
 271
 272 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 273 {
 274         struct v2r1_disk_dqblk *d = dp;
 275         struct mem_dqblk *m = &dquot->dq_dqb;
 276         struct qtree_mem_dqinfo *info =
 277                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 278
 279         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 280         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 281         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 282         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 283         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 284         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 285         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 286         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 287         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 288         if (qtree_entry_unused(info, dp))
 289                 d->dqb_itime = cpu_to_le64(1);
 290 }
 291
 292 static int v2r1_is_id(void *dp, struct dquot *dquot)
 293 {
 294         struct v2r1_disk_dqblk *d = dp;
 295         struct qtree_mem_dqinfo *info =
 296                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 297
 298         if (qtree_entry_unused(info, dp))
 299                 return 0;
 300         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 301                                 le32_to_cpu(d->dqb_id)),
 302                       dquot->dq_id);
 303 }
 304
 305 static int v2_read_dquot(struct dquot *dquot)
 306 {
 307         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 308         int ret;
 309
 310         down_read(&dqopt->dqio_sem);
 311         ret = qtree_read_dquot(
 312                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 313                         dquot);
 314         up_read(&dqopt->dqio_sem);
 315         return ret;
 316 }
 317
 318 static int v2_write_dquot(struct dquot *dquot)
 319 {
 320         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 321         int ret;
 322         bool alloc = false;
 323
 324         /*
 325          * If space for dquot is already allocated, we don't need any
 326          * protection as we'll only overwrite the place of dquot. We are
 327          * still protected by concurrent writes of the same dquot by
 328          * dquot->dq_lock.
 329          */
 330         if (!dquot->dq_off) {
 331                 alloc = true;
 332                 down_write(&dqopt->dqio_sem);
 333         }
 334         ret = qtree_write_dquot(
 335                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 336                         dquot);
 337         if (alloc)
 338                 up_write(&dqopt->dqio_sem);
 339         return ret;
 340 }
 341
 342 static int v2_release_dquot(struct dquot *dquot)
 343 {
 344         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 345         int ret;
 346
 347         down_write(&dqopt->dqio_sem);
 348         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 349         up_write(&dqopt->dqio_sem);
 350
 351         return ret;
 352 }
 353
 354 static int v2_free_file_info(struct super_block *sb, int type)
 355 {
 356         kfree(sb_dqinfo(sb, type)->dqi_priv);
 357         return 0;
 358 }
 359
 360 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 361 {
 362         struct quota_info *dqopt = sb_dqopt(sb);
 363         int ret;
 364
 365         down_read(&dqopt->dqio_sem);
 366         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 367         up_read(&dqopt->dqio_sem);
 368         return ret;
 369 }
 370
 371 static const struct quota_format_ops v2_format_ops = {
 372         .check_quota_file       = v2_check_quota_file,
 373         .read_file_info         = v2_read_file_info,
 374         .write_file_info        = v2_write_file_info,
 375         .free_file_info         = v2_free_file_info,
 376         .read_dqblk             = v2_read_dquot,
 377         .commit_dqblk           = v2_write_dquot,
 378         .release_dqblk          = v2_release_dquot,
 379         .get_next_id            = v2_get_next_id,
 380 };
 381
 382 static struct quota_format_type v2r0_quota_format = {
 383         .qf_fmt_id      = QFMT_VFS_V0,
 384         .qf_ops         = &v2_format_ops,
 385         .qf_owner       = THIS_MODULE
 386 };
 387
 388 static struct quota_format_type v2r1_quota_format = {
 389         .qf_fmt_id      = QFMT_VFS_V1,
 390         .qf_ops         = &v2_format_ops,
 391         .qf_owner       = THIS_MODULE
 392 };
 393
 394 static int __init init_v2_quota_format(void)
 395 {
 396         int ret;
 397
 398         ret = register_quota_format(&v2r0_quota_format);
 399         if (ret)
 400                 return ret;
 401         return register_quota_format(&v2r1_quota_format);
 402 }
 403
 404 static void __exit exit_v2_quota_format(void)
 405 {
 406         unregister_quota_format(&v2r0_quota_format);
 407         unregister_quota_format(&v2r1_quota_format);
 408 }
 409
 410 module_init(init_v2_quota_format);
 411 module_exit(exit_v2_quota_format);