/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Robert Elz at The University of Melbourne.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifndef _LINUX_QUOTA_
#define _LINUX_QUOTA_

#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/percpu_counter.h>

#include <linux/dqblk_xfs.h>
#include <linux/dqblk_v1.h>
#include <linux/dqblk_v2.h>

#include <linux/atomic.h>
#include <linux/uidgid.h>
#include <linux/projid.h>
#include <uapi/linux/quota.h>

#undef USRQUOTA
#undef GRPQUOTA
#undef PRJQUOTA
enum quota_type {
        USRQUOTA = 0,           /* element used for user quotas */
        GRPQUOTA = 1,           /* element used for group quotas */
        PRJQUOTA = 2,           /* element used for project quotas */
};

/* Masks for quota types when used as a bitmask */
#define QTYPE_MASK_USR (1 << USRQUOTA)
#define QTYPE_MASK_GRP (1 << GRPQUOTA)
#define QTYPE_MASK_PRJ (1 << PRJQUOTA)

typedef __kernel_uid32_t qid_t; /* Type in which we store ids in memory */
typedef long long qsize_t;      /* Type in which we store sizes */

struct kqid {                   /* Type in which we store the quota identifier */
        union {
                kuid_t uid;
                kgid_t gid;
                kprojid_t projid;
        };
        enum quota_type type;  /* USRQUOTA (uid) or GRPQUOTA (gid) or PRJQUOTA (projid) */
};

extern bool qid_eq(struct kqid left, struct kqid right);
extern bool qid_lt(struct kqid left, struct kqid right);
extern qid_t from_kqid(struct user_namespace *to, struct kqid qid);
extern qid_t from_kqid_munged(struct user_namespace *to, struct kqid qid);
extern bool qid_valid(struct kqid qid);

/**
 *      make_kqid - Map a user-namespace, type, qid tuple into a kqid.
 *      @from: User namespace that the qid is in
 *      @type: The type of quota
 *      @qid: Quota identifier
 *
 *      Maps a user-namespace, type qid tuple into a kernel internal
 *      kqid, and returns that kqid.
 *
 *      When there is no mapping defined for the user-namespace, type,
 *      qid tuple an invalid kqid is returned.  Callers are expected to
 *      test for and handle handle invalid kqids being returned.
 *      Invalid kqids may be tested for using qid_valid().
 */
static inline struct kqid make_kqid(struct user_namespace *from,
                                    enum quota_type type, qid_t qid)
{
        struct kqid kqid;

        kqid.type = type;
        switch (type) {
        case USRQUOTA:
                kqid.uid = make_kuid(from, qid);
                break;
        case GRPQUOTA:
                kqid.gid = make_kgid(from, qid);
                break;
        case PRJQUOTA:
                kqid.projid = make_kprojid(from, qid);
                break;
        default:
                BUG();
        }
        return kqid;
}

/**
 *      make_kqid_invalid - Explicitly make an invalid kqid
 *      @type: The type of quota identifier
 *
 *      Returns an invalid kqid with the specified type.
 */
static inline struct kqid make_kqid_invalid(enum quota_type type)
{
        struct kqid kqid;

        kqid.type = type;
        switch (type) {
        case USRQUOTA:
                kqid.uid = INVALID_UID;
                break;
        case GRPQUOTA:
                kqid.gid = INVALID_GID;
                break;
        case PRJQUOTA:
                kqid.projid = INVALID_PROJID;
                break;
        default:
                BUG();
        }
        return kqid;
}

/**
 *      make_kqid_uid - Make a kqid from a kuid
 *      @uid: The kuid to make the quota identifier from
 */
static inline struct kqid make_kqid_uid(kuid_t uid)
{
        struct kqid kqid;
        kqid.type = USRQUOTA;
        kqid.uid = uid;
        return kqid;
}

/**
 *      make_kqid_gid - Make a kqid from a kgid
 *      @gid: The kgid to make the quota identifier from
 */
static inline struct kqid make_kqid_gid(kgid_t gid)
{
        struct kqid kqid;
        kqid.type = GRPQUOTA;
        kqid.gid = gid;
        return kqid;
}

/**
 *      make_kqid_projid - Make a kqid from a projid
 *      @projid: The kprojid to make the quota identifier from
 */
static inline struct kqid make_kqid_projid(kprojid_t projid)
{
        struct kqid kqid;
        kqid.type = PRJQUOTA;
        kqid.projid = projid;
        return kqid;
}

/**
 *      qid_has_mapping - Report if a qid maps into a user namespace.
 *      @ns:  The user namespace to see if a value maps into.
 *      @qid: The kernel internal quota identifier to test.
 */
static inline bool qid_has_mapping(struct user_namespace *ns, struct kqid qid)
{
        return from_kqid(ns, qid) != (qid_t) -1;
}


extern spinlock_t dq_data_lock;

/* Maximal numbers of writes for quota operation (insert/delete/update)
 * (over VFS all formats) */
#define DQUOT_INIT_ALLOC max(V1_INIT_ALLOC, V2_INIT_ALLOC)
#define DQUOT_INIT_REWRITE max(V1_INIT_REWRITE, V2_INIT_REWRITE)
#define DQUOT_DEL_ALLOC max(V1_DEL_ALLOC, V2_DEL_ALLOC)
#define DQUOT_DEL_REWRITE max(V1_DEL_REWRITE, V2_DEL_REWRITE)

/*
 * Data for one user/group kept in memory
 */
struct mem_dqblk {
        qsize_t dqb_bhardlimit; /* absolute limit on disk blks alloc */
        qsize_t dqb_bsoftlimit; /* preferred limit on disk blks */
        qsize_t dqb_curspace;   /* current used space */
        qsize_t dqb_rsvspace;   /* current reserved space for delalloc*/
        qsize_t dqb_ihardlimit; /* absolute limit on allocated inodes */
        qsize_t dqb_isoftlimit; /* preferred inode limit */
        qsize_t dqb_curinodes;  /* current # allocated inodes */
        time64_t dqb_btime;     /* time limit for excessive disk use */
        time64_t dqb_itime;     /* time limit for excessive inode use */
};

/*
 * Data for one quotafile kept in memory
 */
struct quota_format_type;

struct mem_dqinfo {
        struct quota_format_type *dqi_format;
        int dqi_fmt_id;         /* Id of the dqi_format - used when turning
                                 * quotas on after remount RW */
        struct list_head dqi_dirty_list;        /* List of dirty dquots [dq_list_lock] */
        unsigned long dqi_flags;        /* DFQ_ flags [dq_data_lock] */
        unsigned int dqi_bgrace;        /* Space grace time [dq_data_lock] */
        unsigned int dqi_igrace;        /* Inode grace time [dq_data_lock] */
        qsize_t dqi_max_spc_limit;      /* Maximum space limit [static] */
        qsize_t dqi_max_ino_limit;      /* Maximum inode limit [static] */
        void *dqi_priv;
};

struct super_block;

/* Mask for flags passed to userspace */
#define DQF_GETINFO_MASK (DQF_ROOT_SQUASH | DQF_SYS_FILE)
/* Mask for flags modifiable from userspace */
#define DQF_SETINFO_MASK DQF_ROOT_SQUASH

enum {
        DQF_INFO_DIRTY_B = DQF_PRIVATE,
};
#define DQF_INFO_DIRTY (1 << DQF_INFO_DIRTY_B)  /* Is info dirty? */

extern void mark_info_dirty(struct super_block *sb, int type);
static inline int info_dirty(struct mem_dqinfo *info)
{
        return test_bit(DQF_INFO_DIRTY_B, &info->dqi_flags);
}

enum {
        DQST_LOOKUPS,
        DQST_DROPS,
        DQST_READS,
        DQST_WRITES,
        DQST_CACHE_HITS,
        DQST_ALLOC_DQUOTS,
        DQST_FREE_DQUOTS,
        DQST_SYNCS,
        _DQST_DQSTAT_LAST
};

struct dqstats {
        int stat[_DQST_DQSTAT_LAST];
        struct percpu_counter counter[_DQST_DQSTAT_LAST];
};

extern struct dqstats dqstats;

static inline void dqstats_inc(unsigned int type)
{
        percpu_counter_inc(&dqstats.counter[type]);
}

static inline void dqstats_dec(unsigned int type)
{
        percpu_counter_dec(&dqstats.counter[type]);
}

#define DQ_MOD_B        0       /* dquot modified since read */
#define DQ_BLKS_B       1       /* uid/gid has been warned about blk limit */
#define DQ_INODES_B     2       /* uid/gid has been warned about inode limit */
#define DQ_FAKE_B       3       /* no limits only usage */
#define DQ_READ_B       4       /* dquot was read into memory */
#define DQ_ACTIVE_B     5       /* dquot is active (dquot_release not called) */
#define DQ_LASTSET_B    6       /* Following 6 bits (see QIF_) are reserved\
                                 * for the mask of entries set via SETQUOTA\
                                 * quotactl. They are set under dq_data_lock\
                                 * and the quota format handling dquot can\
                                 * clear them when it sees fit. */

struct dquot {
        struct hlist_node dq_hash;      /* Hash list in memory [dq_list_lock] */
        struct list_head dq_inuse;      /* List of all quotas [dq_list_lock] */
        struct list_head dq_free;       /* Free list element [dq_list_lock] */
        struct list_head dq_dirty;      /* List of dirty dquots [dq_list_lock] */
        struct mutex dq_lock;           /* dquot IO lock */
        spinlock_t dq_dqb_lock;         /* Lock protecting dq_dqb changes */
        atomic_t dq_count;              /* Use count */
        struct super_block *dq_sb;      /* superblock this applies to */
        struct kqid dq_id;              /* ID this applies to (uid, gid, projid) */
        loff_t dq_off;                  /* Offset of dquot on disk [dq_lock, stable once set] */
        unsigned long dq_flags;         /* See DQ_* */
        struct mem_dqblk dq_dqb;        /* Diskquota usage [dq_dqb_lock] */
};

/* Operations which must be implemented by each quota format */
struct quota_format_ops {
        int (*check_quota_file)(struct super_block *sb, int type);      /* Detect whether file is in our format */
        int (*read_file_info)(struct super_block *sb, int type);        /* Read main info about file - called on quotaon() */
        int (*write_file_info)(struct super_block *sb, int type);       /* Write main info about file */
        int (*free_file_info)(struct super_block *sb, int type);        /* Called on quotaoff() */
        int (*read_dqblk)(struct dquot *dquot);         /* Read structure for one user */
        int (*commit_dqblk)(struct dquot *dquot);       /* Write structure for one user */
        int (*release_dqblk)(struct dquot *dquot);      /* Called when last reference to dquot is being dropped */
        int (*get_next_id)(struct super_block *sb, struct kqid *qid);   /* Get next ID with existing structure in the quota file */
};

/* Operations working with dquots */
struct dquot_operations {
        int (*write_dquot) (struct dquot *);            /* Ordinary dquot write */
        struct dquot *(*alloc_dquot)(struct super_block *, int);        /* Allocate memory for new dquot */
        void (*destroy_dquot)(struct dquot *);          /* Free memory for dquot */
        int (*acquire_dquot) (struct dquot *);          /* Quota is going to be created on disk */
        int (*release_dquot) (struct dquot *);          /* Quota is going to be deleted from disk */
        int (*mark_dirty) (struct dquot *);             /* Dquot is marked dirty */
        int (*write_info) (struct super_block *, int);  /* Write of quota "superblock" */
        /* get reserved quota for delayed alloc, value returned is managed by
         * quota code only */
        qsize_t *(*get_reserved_space) (struct inode *);
        int (*get_projid) (struct inode *, kprojid_t *);/* Get project ID */
        /* Get number of inodes that were charged for a given inode */
        int (*get_inode_usage) (struct inode *, qsize_t *);
        /* Get next ID with active quota structure */
        int (*get_next_id) (struct super_block *sb, struct kqid *qid);
};

struct path;

/* Structure for communicating via ->get_dqblk() & ->set_dqblk() */
struct qc_dqblk {
        int d_fieldmask;        /* mask of fields to change in ->set_dqblk() */
        u64 d_spc_hardlimit;    /* absolute limit on used space */
        u64 d_spc_softlimit;    /* preferred limit on used space */
        u64 d_ino_hardlimit;    /* maximum # allocated inodes */
        u64 d_ino_softlimit;    /* preferred inode limit */
        u64 d_space;            /* Space owned by the user */
        u64 d_ino_count;        /* # inodes owned by the user */
        s64 d_ino_timer;        /* zero if within inode limits */
                                /* if not, we refuse service */
        s64 d_spc_timer;        /* similar to above; for space */
        int d_ino_warns;        /* # warnings issued wrt num inodes */
        int d_spc_warns;        /* # warnings issued wrt used space */
        u64 d_rt_spc_hardlimit; /* absolute limit on realtime space */
        u64 d_rt_spc_softlimit; /* preferred limit on RT space */
        u64 d_rt_space;         /* realtime space owned */
        s64 d_rt_spc_timer;     /* similar to above; for RT space */
        int d_rt_spc_warns;     /* # warnings issued wrt RT space */
};

/*
 * Field specifiers for ->set_dqblk() in struct qc_dqblk and also for
 * ->set_info() in struct qc_info
 */
#define QC_INO_SOFT     (1<<0)
#define QC_INO_HARD     (1<<1)
#define QC_SPC_SOFT     (1<<2)
#define QC_SPC_HARD     (1<<3)
#define QC_RT_SPC_SOFT  (1<<4)
#define QC_RT_SPC_HARD  (1<<5)
#define QC_LIMIT_MASK (QC_INO_SOFT | QC_INO_HARD | QC_SPC_SOFT | QC_SPC_HARD | \
                       QC_RT_SPC_SOFT | QC_RT_SPC_HARD)
#define QC_SPC_TIMER    (1<<6)
#define QC_INO_TIMER    (1<<7)
#define QC_RT_SPC_TIMER (1<<8)
#define QC_TIMER_MASK (QC_SPC_TIMER | QC_INO_TIMER | QC_RT_SPC_TIMER)
#define QC_SPC_WARNS    (1<<9)
#define QC_INO_WARNS    (1<<10)
#define QC_RT_SPC_WARNS (1<<11)
#define QC_WARNS_MASK (QC_SPC_WARNS | QC_INO_WARNS | QC_RT_SPC_WARNS)
#define QC_SPACE        (1<<12)
#define QC_INO_COUNT    (1<<13)
#define QC_RT_SPACE     (1<<14)
#define QC_ACCT_MASK (QC_SPACE | QC_INO_COUNT | QC_RT_SPACE)
#define QC_FLAGS        (1<<15)

#define QCI_SYSFILE             (1 << 0)        /* Quota file is hidden from userspace */
#define QCI_ROOT_SQUASH         (1 << 1)        /* Root squash turned on */
#define QCI_ACCT_ENABLED        (1 << 2)        /* Quota accounting enabled */
#define QCI_LIMITS_ENFORCED     (1 << 3)        /* Quota limits enforced */

/* Structures for communicating via ->get_state */
struct qc_type_state {
        unsigned int flags;             /* Flags QCI_* */
        unsigned int spc_timelimit;     /* Time after which space softlimit is
                                         * enforced */
        unsigned int ino_timelimit;     /* Ditto for inode softlimit */
        unsigned int rt_spc_timelimit;  /* Ditto for real-time space */
        unsigned int spc_warnlimit;     /* Limit for number of space warnings */
        unsigned int ino_warnlimit;     /* Ditto for inodes */
        unsigned int rt_spc_warnlimit;  /* Ditto for real-time space */
        unsigned long long ino;         /* Inode number of quota file */
        blkcnt_t blocks;                /* Number of 512-byte blocks in the file */
        blkcnt_t nextents;              /* Number of extents in the file */
};

struct qc_state {
        unsigned int s_incoredqs;       /* Number of dquots in core */
        struct qc_type_state s_state[MAXQUOTAS];  /* Per quota type information */
};

/* Structure for communicating via ->set_info */
struct qc_info {
        int i_fieldmask;        /* mask of fields to change in ->set_info() */
        unsigned int i_flags;           /* Flags QCI_* */
        unsigned int i_spc_timelimit;   /* Time after which space softlimit is
                                         * enforced */
        unsigned int i_ino_timelimit;   /* Ditto for inode softlimit */
        unsigned int i_rt_spc_timelimit;/* Ditto for real-time space */
        unsigned int i_spc_warnlimit;   /* Limit for number of space warnings */
        unsigned int i_ino_warnlimit;   /* Limit for number of inode warnings */
        unsigned int i_rt_spc_warnlimit;        /* Ditto for real-time space */
};

/* Operations handling requests from userspace */
struct quotactl_ops {
        int (*quota_on)(struct super_block *, int, int, const struct path *);
        int (*quota_off)(struct super_block *, int);
        int (*quota_enable)(struct super_block *, unsigned int);
        int (*quota_disable)(struct super_block *, unsigned int);
        int (*quota_sync)(struct super_block *, int);
        int (*set_info)(struct super_block *, int, struct qc_info *);
        int (*get_dqblk)(struct super_block *, struct kqid, struct qc_dqblk *);
        int (*get_nextdqblk)(struct super_block *, struct kqid *,
                             struct qc_dqblk *);
        int (*set_dqblk)(struct super_block *, struct kqid, struct qc_dqblk *);
        int (*get_state)(struct super_block *, struct qc_state *);
        int (*rm_xquota)(struct super_block *, unsigned int);
};

struct quota_format_type {
        int qf_fmt_id;  /* Quota format id */
        const struct quota_format_ops *qf_ops;  /* Operations of format */
        struct module *qf_owner;                /* Module implementing quota format */
        struct quota_format_type *qf_next;
};

/**
 * Quota state flags - they actually come in two flavors - for users and groups.
 *
 * Actual typed flags layout:
 *                              USRQUOTA        GRPQUOTA
 *  DQUOT_USAGE_ENABLED         0x0001          0x0002
 *  DQUOT_LIMITS_ENABLED        0x0004          0x0008
 *  DQUOT_SUSPENDED             0x0010          0x0020
 *
 * Following bits are used for non-typed flags:
 *  DQUOT_QUOTA_SYS_FILE        0x0040
 *  DQUOT_NEGATIVE_USAGE        0x0080
 */
enum {
        _DQUOT_USAGE_ENABLED = 0,               /* Track disk usage for users */
        _DQUOT_LIMITS_ENABLED,                  /* Enforce quota limits for users */
        _DQUOT_SUSPENDED,                       /* User diskquotas are off, but
                                                 * we have necessary info in
                                                 * memory to turn them on */
        _DQUOT_STATE_FLAGS
};
#define DQUOT_USAGE_ENABLED     (1 << _DQUOT_USAGE_ENABLED * MAXQUOTAS)
#define DQUOT_LIMITS_ENABLED    (1 << _DQUOT_LIMITS_ENABLED * MAXQUOTAS)
#define DQUOT_SUSPENDED         (1 << _DQUOT_SUSPENDED * MAXQUOTAS)
#define DQUOT_STATE_FLAGS       (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED | \
                                 DQUOT_SUSPENDED)
/* Other quota flags */
#define DQUOT_STATE_LAST        (_DQUOT_STATE_FLAGS * MAXQUOTAS)
#define DQUOT_QUOTA_SYS_FILE    (1 << DQUOT_STATE_LAST)
                                                /* Quota file is a special
                                                 * system file and user cannot
                                                 * touch it. Filesystem is
                                                 * responsible for setting
                                                 * S_NOQUOTA, S_NOATIME flags
                                                 */
#define DQUOT_NEGATIVE_USAGE    (1 << (DQUOT_STATE_LAST + 1))
                                               /* Allow negative quota usage */
/* Do not track dirty dquots in a list */
#define DQUOT_NOLIST_DIRTY      (1 << (DQUOT_STATE_LAST + 2))

static inline unsigned int dquot_state_flag(unsigned int flags, int type)
{
        return flags << type;
}

static inline unsigned int dquot_generic_flag(unsigned int flags, int type)
{
        return (flags >> type) & DQUOT_STATE_FLAGS;
}

/* Bitmap of quota types where flag is set in flags */
static __always_inline unsigned dquot_state_types(unsigned flags, unsigned flag)
{
        BUILD_BUG_ON_NOT_POWER_OF_2(flag);
        return (flags / flag) & ((1 << MAXQUOTAS) - 1);
}

#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
extern void quota_send_warning(struct kqid qid, dev_t dev,
                               const char warntype);
#else
static inline void quota_send_warning(struct kqid qid, dev_t dev,
                                      const char warntype)
{
        return;
}
#endif /* CONFIG_QUOTA_NETLINK_INTERFACE */

struct quota_info {
        unsigned int flags;                     /* Flags for diskquotas on this device */
        struct rw_semaphore dqio_sem;           /* Lock quota file while I/O in progress */
        struct inode *files[MAXQUOTAS];         /* inodes of quotafiles */
        struct mem_dqinfo info[MAXQUOTAS];      /* Information for each quota type */
        const struct quota_format_ops *ops[MAXQUOTAS];  /* Operations for each type */
};

int register_quota_format(struct quota_format_type *fmt);
void unregister_quota_format(struct quota_format_type *fmt);

struct quota_module_name {
        int qm_fmt_id;
        char *qm_mod_name;
};

#define INIT_QUOTA_MODULE_NAMES {\
        {QFMT_VFS_OLD, "quota_v1"},\
        {QFMT_VFS_V0, "quota_v2"},\
        {QFMT_VFS_V1, "quota_v2"},\
        {0, NULL}}

#endif /* _QUOTA_ */