include/linux/quota.h

   1 /*
   2  * Copyright (c) 1982, 1986 Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Robert Elz at The University of Melbourne.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32 #ifndef _LINUX_QUOTA_
  33 #define _LINUX_QUOTA_
  34
  35 #include <linux/list.h>
  36 #include <linux/mutex.h>
  37 #include <linux/rwsem.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/wait.h>
  40 #include <linux/percpu_counter.h>
  41
  42 #include <linux/dqblk_xfs.h>
  43 #include <linux/dqblk_v1.h>
  44 #include <linux/dqblk_v2.h>
  45
  46 #include <linux/atomic.h>
  47 #include <linux/uidgid.h>
  48 #include <linux/projid.h>
  49 #include <uapi/linux/quota.h>
  50
  51 #undef USRQUOTA
  52 #undef GRPQUOTA
  53 enum quota_type {
  54         USRQUOTA = 0,           /* element used for user quotas */
  55         GRPQUOTA = 1,           /* element used for group quotas */
  56         PRJQUOTA = 2,           /* element used for project quotas */
  57 };
  58
  59 /* Masks for quota types when used as a bitmask */
  60 #define QTYPE_MASK_USR (1 << USRQUOTA)
  61 #define QTYPE_MASK_GRP (1 << GRPQUOTA)
  62 #define QTYPE_MASK_PRJ (1 << PRJQUOTA)
  63
  64 typedef __kernel_uid32_t qid_t; /* Type in which we store ids in memory */
  65 typedef long long qsize_t;      /* Type in which we store sizes */
  66
  67 struct kqid {                   /* Type in which we store the quota identifier */
  68         union {
  69                 kuid_t uid;
  70                 kgid_t gid;
  71                 kprojid_t projid;
  72         };
  73         enum quota_type type;  /* USRQUOTA (uid) or GRPQUOTA (gid) or PRJQUOTA (projid) */
  74 };
  75
  76 extern bool qid_eq(struct kqid left, struct kqid right);
  77 extern bool qid_lt(struct kqid left, struct kqid right);
  78 extern qid_t from_kqid(struct user_namespace *to, struct kqid qid);
  79 extern qid_t from_kqid_munged(struct user_namespace *to, struct kqid qid);
  80 extern bool qid_valid(struct kqid qid);
  81
  82 /**
  83  *      make_kqid - Map a user-namespace, type, qid tuple into a kqid.
  84  *      @from: User namespace that the qid is in
  85  *      @type: The type of quota
  86  *      @qid: Quota identifier
  87  *
  88  *      Maps a user-namespace, type qid tuple into a kernel internal
  89  *      kqid, and returns that kqid.
  90  *
  91  *      When there is no mapping defined for the user-namespace, type,
  92  *      qid tuple an invalid kqid is returned.  Callers are expected to
  93  *      test for and handle handle invalid kqids being returned.
  94  *      Invalid kqids may be tested for using qid_valid().
  95  */
  96 static inline struct kqid make_kqid(struct user_namespace *from,
  97                                     enum quota_type type, qid_t qid)
  98 {
  99         struct kqid kqid;
 100
 101         kqid.type = type;
 102         switch (type) {
 103         case USRQUOTA:
 104                 kqid.uid = make_kuid(from, qid);
 105                 break;
 106         case GRPQUOTA:
 107                 kqid.gid = make_kgid(from, qid);
 108                 break;
 109         case PRJQUOTA:
 110                 kqid.projid = make_kprojid(from, qid);
 111                 break;
 112         default:
 113                 BUG();
 114         }
 115         return kqid;
 116 }
 117
 118 /**
 119  *      make_kqid_invalid - Explicitly make an invalid kqid
 120  *      @type: The type of quota identifier
 121  *
 122  *      Returns an invalid kqid with the specified type.
 123  */
 124 static inline struct kqid make_kqid_invalid(enum quota_type type)
 125 {
 126         struct kqid kqid;
 127
 128         kqid.type = type;
 129         switch (type) {
 130         case USRQUOTA:
 131                 kqid.uid = INVALID_UID;
 132                 break;
 133         case GRPQUOTA:
 134                 kqid.gid = INVALID_GID;
 135                 break;
 136         case PRJQUOTA:
 137                 kqid.projid = INVALID_PROJID;
 138                 break;
 139         default:
 140                 BUG();
 141         }
 142         return kqid;
 143 }
 144
 145 /**
 146  *      make_kqid_uid - Make a kqid from a kuid
 147  *      @uid: The kuid to make the quota identifier from
 148  */
 149 static inline struct kqid make_kqid_uid(kuid_t uid)
 150 {
 151         struct kqid kqid;
 152         kqid.type = USRQUOTA;
 153         kqid.uid = uid;
 154         return kqid;
 155 }
 156
 157 /**
 158  *      make_kqid_gid - Make a kqid from a kgid
 159  *      @gid: The kgid to make the quota identifier from
 160  */
 161 static inline struct kqid make_kqid_gid(kgid_t gid)
 162 {
 163         struct kqid kqid;
 164         kqid.type = GRPQUOTA;
 165         kqid.gid = gid;
 166         return kqid;
 167 }
 168
 169 /**
 170  *      make_kqid_projid - Make a kqid from a projid
 171  *      @projid: The kprojid to make the quota identifier from
 172  */
 173 static inline struct kqid make_kqid_projid(kprojid_t projid)
 174 {
 175         struct kqid kqid;
 176         kqid.type = PRJQUOTA;
 177         kqid.projid = projid;
 178         return kqid;
 179 }
 180
 181
 182 extern spinlock_t dq_data_lock;
 183
 184 /* Maximal numbers of writes for quota operation (insert/delete/update)
 185  * (over VFS all formats) */
 186 #define DQUOT_INIT_ALLOC max(V1_INIT_ALLOC, V2_INIT_ALLOC)
 187 #define DQUOT_INIT_REWRITE max(V1_INIT_REWRITE, V2_INIT_REWRITE)
 188 #define DQUOT_DEL_ALLOC max(V1_DEL_ALLOC, V2_DEL_ALLOC)
 189 #define DQUOT_DEL_REWRITE max(V1_DEL_REWRITE, V2_DEL_REWRITE)
 190
 191 /*
 192  * Data for one user/group kept in memory
 193  */
 194 struct mem_dqblk {
 195         qsize_t dqb_bhardlimit; /* absolute limit on disk blks alloc */
 196         qsize_t dqb_bsoftlimit; /* preferred limit on disk blks */
 197         qsize_t dqb_curspace;   /* current used space */
 198         qsize_t dqb_rsvspace;   /* current reserved space for delalloc*/
 199         qsize_t dqb_ihardlimit; /* absolute limit on allocated inodes */
 200         qsize_t dqb_isoftlimit; /* preferred inode limit */
 201         qsize_t dqb_curinodes;  /* current # allocated inodes */
 202         time_t dqb_btime;       /* time limit for excessive disk use */
 203         time_t dqb_itime;       /* time limit for excessive inode use */
 204 };
 205
 206 /*
 207  * Data for one quotafile kept in memory
 208  */
 209 struct quota_format_type;
 210
 211 struct mem_dqinfo {
 212         struct quota_format_type *dqi_format;
 213         int dqi_fmt_id;         /* Id of the dqi_format - used when turning
 214                                  * quotas on after remount RW */
 215         struct list_head dqi_dirty_list;        /* List of dirty dquots */
 216         unsigned long dqi_flags;
 217         unsigned int dqi_bgrace;
 218         unsigned int dqi_igrace;
 219         qsize_t dqi_maxblimit;
 220         qsize_t dqi_maxilimit;
 221         void *dqi_priv;
 222 };
 223
 224 struct super_block;
 225
 226 #define DQF_MASK 0xffff         /* Mask for format specific flags */
 227 #define DQF_GETINFO_MASK 0x1ffff        /* Mask for flags passed to userspace */
 228 #define DQF_SETINFO_MASK 0xffff         /* Mask for flags modifiable from userspace */
 229 #define DQF_SYS_FILE_B          16
 230 #define DQF_SYS_FILE (1 << DQF_SYS_FILE_B)      /* Quota file stored as system file */
 231 #define DQF_INFO_DIRTY_B        31
 232 #define DQF_INFO_DIRTY (1 << DQF_INFO_DIRTY_B)  /* Is info dirty? */
 233
 234 extern void mark_info_dirty(struct super_block *sb, int type);
 235 static inline int info_dirty(struct mem_dqinfo *info)
 236 {
 237         return test_bit(DQF_INFO_DIRTY_B, &info->dqi_flags);
 238 }
 239
 240 enum {
 241         DQST_LOOKUPS,
 242         DQST_DROPS,
 243         DQST_READS,
 244         DQST_WRITES,
 245         DQST_CACHE_HITS,
 246         DQST_ALLOC_DQUOTS,
 247         DQST_FREE_DQUOTS,
 248         DQST_SYNCS,
 249         _DQST_DQSTAT_LAST
 250 };
 251
 252 struct dqstats {
 253         int stat[_DQST_DQSTAT_LAST];
 254         struct percpu_counter counter[_DQST_DQSTAT_LAST];
 255 };
 256
 257 extern struct dqstats *dqstats_pcpu;
 258 extern struct dqstats dqstats;
 259
 260 static inline void dqstats_inc(unsigned int type)
 261 {
 262         percpu_counter_inc(&dqstats.counter[type]);
 263 }
 264
 265 static inline void dqstats_dec(unsigned int type)
 266 {
 267         percpu_counter_dec(&dqstats.counter[type]);
 268 }
 269
 270 #define DQ_MOD_B        0       /* dquot modified since read */
 271 #define DQ_BLKS_B       1       /* uid/gid has been warned about blk limit */
 272 #define DQ_INODES_B     2       /* uid/gid has been warned about inode limit */
 273 #define DQ_FAKE_B       3       /* no limits only usage */
 274 #define DQ_READ_B       4       /* dquot was read into memory */
 275 #define DQ_ACTIVE_B     5       /* dquot is active (dquot_release not called) */
 276 #define DQ_LASTSET_B    6       /* Following 6 bits (see QIF_) are reserved\
 277                                  * for the mask of entries set via SETQUOTA\
 278                                  * quotactl. They are set under dq_data_lock\
 279                                  * and the quota format handling dquot can\
 280                                  * clear them when it sees fit. */
 281
 282 struct dquot {
 283         struct hlist_node dq_hash;      /* Hash list in memory */
 284         struct list_head dq_inuse;      /* List of all quotas */
 285         struct list_head dq_free;       /* Free list element */
 286         struct list_head dq_dirty;      /* List of dirty dquots */
 287         struct mutex dq_lock;           /* dquot IO lock */
 288         atomic_t dq_count;              /* Use count */
 289         wait_queue_head_t dq_wait_unused;       /* Wait queue for dquot to become unused */
 290         struct super_block *dq_sb;      /* superblock this applies to */
 291         struct kqid dq_id;              /* ID this applies to (uid, gid, projid) */
 292         loff_t dq_off;                  /* Offset of dquot on disk */
 293         unsigned long dq_flags;         /* See DQ_* */
 294         struct mem_dqblk dq_dqb;        /* Diskquota usage */
 295 };
 296
 297 /* Operations which must be implemented by each quota format */
 298 struct quota_format_ops {
 299         int (*check_quota_file)(struct super_block *sb, int type);      /* Detect whether file is in our format */
 300         int (*read_file_info)(struct super_block *sb, int type);        /* Read main info about file - called on quotaon() */
 301         int (*write_file_info)(struct super_block *sb, int type);       /* Write main info about file */
 302         int (*free_file_info)(struct super_block *sb, int type);        /* Called on quotaoff() */
 303         int (*read_dqblk)(struct dquot *dquot);         /* Read structure for one user */
 304         int (*commit_dqblk)(struct dquot *dquot);       /* Write structure for one user */
 305         int (*release_dqblk)(struct dquot *dquot);      /* Called when last reference to dquot is being dropped */
 306 };
 307
 308 /* Operations working with dquots */
 309 struct dquot_operations {
 310         int (*write_dquot) (struct dquot *);            /* Ordinary dquot write */
 311         struct dquot *(*alloc_dquot)(struct super_block *, int);        /* Allocate memory for new dquot */
 312         void (*destroy_dquot)(struct dquot *);          /* Free memory for dquot */
 313         int (*acquire_dquot) (struct dquot *);          /* Quota is going to be created on disk */
 314         int (*release_dquot) (struct dquot *);          /* Quota is going to be deleted from disk */
 315         int (*mark_dirty) (struct dquot *);             /* Dquot is marked dirty */
 316         int (*write_info) (struct super_block *, int);  /* Write of quota "superblock" */
 317         /* get reserved quota for delayed alloc, value returned is managed by
 318          * quota code only */
 319         qsize_t *(*get_reserved_space) (struct inode *);
 320 };
 321
 322 struct path;
 323
 324 /* Operations handling requests from userspace */
 325 struct quotactl_ops {
 326         int (*quota_on)(struct super_block *, int, int, struct path *);
 327         int (*quota_on_meta)(struct super_block *, int, int);
 328         int (*quota_off)(struct super_block *, int);
 329         int (*quota_sync)(struct super_block *, int);
 330         int (*get_info)(struct super_block *, int, struct if_dqinfo *);
 331         int (*set_info)(struct super_block *, int, struct if_dqinfo *);
 332         int (*get_dqblk)(struct super_block *, struct kqid, struct fs_disk_quota *);
 333         int (*set_dqblk)(struct super_block *, struct kqid, struct fs_disk_quota *);
 334         int (*get_xstate)(struct super_block *, struct fs_quota_stat *);
 335         int (*set_xstate)(struct super_block *, unsigned int, int);
 336         int (*get_xstatev)(struct super_block *, struct fs_quota_statv *);
 337         int (*rm_xquota)(struct super_block *, unsigned int);
 338 };
 339
 340 struct quota_format_type {
 341         int qf_fmt_id;  /* Quota format id */
 342         const struct quota_format_ops *qf_ops;  /* Operations of format */
 343         struct module *qf_owner;                /* Module implementing quota format */
 344         struct quota_format_type *qf_next;
 345 };
 346
 347 /* Quota state flags - they actually come in two flavors - for users and groups */
 348 enum {
 349         _DQUOT_USAGE_ENABLED = 0,               /* Track disk usage for users */
 350         _DQUOT_LIMITS_ENABLED,                  /* Enforce quota limits for users */
 351         _DQUOT_SUSPENDED,                       /* User diskquotas are off, but
 352                                                  * we have necessary info in
 353                                                  * memory to turn them on */
 354         _DQUOT_STATE_FLAGS
 355 };
 356 #define DQUOT_USAGE_ENABLED     (1 << _DQUOT_USAGE_ENABLED)
 357 #define DQUOT_LIMITS_ENABLED    (1 << _DQUOT_LIMITS_ENABLED)
 358 #define DQUOT_SUSPENDED         (1 << _DQUOT_SUSPENDED)
 359 #define DQUOT_STATE_FLAGS       (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED | \
 360                                  DQUOT_SUSPENDED)
 361 /* Other quota flags */
 362 #define DQUOT_STATE_LAST        (_DQUOT_STATE_FLAGS * MAXQUOTAS)
 363 #define DQUOT_QUOTA_SYS_FILE    (1 << DQUOT_STATE_LAST)
 364                                                 /* Quota file is a special
 365                                                  * system file and user cannot
 366                                                  * touch it. Filesystem is
 367                                                  * responsible for setting
 368                                                  * S_NOQUOTA, S_NOATIME flags
 369                                                  */
 370 #define DQUOT_NEGATIVE_USAGE    (1 << (DQUOT_STATE_LAST + 1))
 371                                                /* Allow negative quota usage */
 372
 373 static inline unsigned int dquot_state_flag(unsigned int flags, int type)
 374 {
 375         return flags << _DQUOT_STATE_FLAGS * type;
 376 }
 377
 378 static inline unsigned int dquot_generic_flag(unsigned int flags, int type)
 379 {
 380         return (flags >> _DQUOT_STATE_FLAGS * type) & DQUOT_STATE_FLAGS;
 381 }
 382
 383 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
 384 extern void quota_send_warning(struct kqid qid, dev_t dev,
 385                                const char warntype);
 386 #else
 387 static inline void quota_send_warning(struct kqid qid, dev_t dev,
 388                                       const char warntype)
 389 {
 390         return;
 391 }
 392 #endif /* CONFIG_QUOTA_NETLINK_INTERFACE */
 393
 394 struct quota_info {
 395         unsigned int flags;                     /* Flags for diskquotas on this device */
 396         struct mutex dqio_mutex;                /* lock device while I/O in progress */
 397         struct mutex dqonoff_mutex;             /* Serialize quotaon & quotaoff */
 398         struct inode *files[MAXQUOTAS];         /* inodes of quotafiles */
 399         struct mem_dqinfo info[MAXQUOTAS];      /* Information for each quota type */
 400         const struct quota_format_ops *ops[MAXQUOTAS];  /* Operations for each type */
 401 };
 402
 403 int register_quota_format(struct quota_format_type *fmt);
 404 void unregister_quota_format(struct quota_format_type *fmt);
 405
 406 struct quota_module_name {
 407         int qm_fmt_id;
 408         char *qm_mod_name;
 409 };
 410
 411 #define INIT_QUOTA_MODULE_NAMES {\
 412         {QFMT_VFS_OLD, "quota_v1"},\
 413         {QFMT_VFS_V0, "quota_v2"},\
 414         {QFMT_VFS_V1, "quota_v2"},\
 415         {0, NULL}}
 416
 417 #endif /* _QUOTA_ */