// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_DQUOT_H__
#define __XFS_DQUOT_H__

/*
 * Dquots are structures that hold quota information about a user or a group,
 * much like inodes are for files. In fact, dquots share many characteristics
 * with inodes. However, dquots can also be a centralized resource, relative
 * to a collection of inodes. In this respect, dquots share some characteristics
 * of the superblock.
 * XFS dquots exploit both those in its algorithms. They make every attempt
 * to not be a bottleneck when quotas are on and have minimal impact, if any,
 * when quotas are off.
 */

struct xfs_mount;
struct xfs_trans;

enum {
        XFS_QLOWSP_1_PCNT = 0,
        XFS_QLOWSP_3_PCNT,
        XFS_QLOWSP_5_PCNT,
        XFS_QLOWSP_MAX
};

struct xfs_dquot_res {
        /* Total resources allocated and reserved. */
        xfs_qcnt_t              reserved;

        /* Total resources allocated. */
        xfs_qcnt_t              count;

        /* Absolute and preferred limits. */
        xfs_qcnt_t              hardlimit;
        xfs_qcnt_t              softlimit;

        /*
         * For root dquots, this is the default grace period, in seconds.
         * Otherwise, this is when the quota grace period expires,
         * in seconds since the Unix epoch.
         */
        time64_t                timer;
};

static inline bool
xfs_dquot_res_over_limits(
        const struct xfs_dquot_res      *qres)
{
        if ((qres->softlimit && qres->softlimit < qres->reserved) ||
            (qres->hardlimit && qres->hardlimit < qres->reserved))
                return true;
        return false;
}

struct xfs_dquot_pre {
        xfs_qcnt_t              q_prealloc_lo_wmark;
        xfs_qcnt_t              q_prealloc_hi_wmark;
        int64_t                 q_low_space[XFS_QLOWSP_MAX];
};

/*
 * The incore dquot structure
 */
struct xfs_dquot {
        struct list_head        q_lru;
        struct xfs_mount        *q_mount;
        xfs_dqtype_t            q_type;
        uint16_t                q_flags;
        xfs_dqid_t              q_id;
        struct lockref          q_lockref;
        int                     q_bufoffset;
        xfs_daddr_t             q_blkno;
        xfs_fileoff_t           q_fileoffset;

        struct xfs_dquot_res    q_blk;  /* regular blocks */
        struct xfs_dquot_res    q_ino;  /* inodes */
        struct xfs_dquot_res    q_rtb;  /* realtime blocks */

        struct xfs_dq_logitem   q_logitem;

        struct xfs_dquot_pre    q_blk_prealloc;
        struct xfs_dquot_pre    q_rtb_prealloc;

        struct mutex            q_qlock;
        struct completion       q_flush;
        atomic_t                q_pincount;
        struct wait_queue_head  q_pinwait;
};

/*
 * Lock hierarchy for q_qlock:
 *      XFS_QLOCK_NORMAL is the implicit default,
 *      XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
 */
enum {
        XFS_QLOCK_NORMAL = 0,
        XFS_QLOCK_NESTED,
};

/*
 * Manage the q_flush completion queue embedded in the dquot. This completion
 * queue synchronizes processes attempting to flush the in-core dquot back to
 * disk.
 */
static inline void xfs_dqflock(struct xfs_dquot *dqp)
{
        wait_for_completion(&dqp->q_flush);
}

static inline bool xfs_dqflock_nowait(struct xfs_dquot *dqp)
{
        return try_wait_for_completion(&dqp->q_flush);
}

static inline void xfs_dqfunlock(struct xfs_dquot *dqp)
{
        complete(&dqp->q_flush);
}

static inline int
xfs_dquot_type(const struct xfs_dquot *dqp)
{
        return dqp->q_type & XFS_DQTYPE_REC_MASK;
}

static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)
{
        switch (type) {
        case XFS_DQTYPE_USER:
                return XFS_IS_UQUOTA_ON(mp);
        case XFS_DQTYPE_GROUP:
                return XFS_IS_GQUOTA_ON(mp);
        case XFS_DQTYPE_PROJ:
                return XFS_IS_PQUOTA_ON(mp);
        default:
                return 0;
        }
}

static inline struct xfs_dquot *xfs_inode_dquot(
        struct xfs_inode        *ip,
        xfs_dqtype_t            type)
{
        if (xfs_is_metadir_inode(ip))
                return NULL;

        switch (type) {
        case XFS_DQTYPE_USER:
                return ip->i_udquot;
        case XFS_DQTYPE_GROUP:
                return ip->i_gdquot;
        case XFS_DQTYPE_PROJ:
                return ip->i_pdquot;
        default:
                return NULL;
        }
}

/* Decide if the dquot's limits are actually being enforced. */
static inline bool
xfs_dquot_is_enforced(
        const struct xfs_dquot  *dqp)
{
        switch (xfs_dquot_type(dqp)) {
        case XFS_DQTYPE_USER:
                return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
        case XFS_DQTYPE_GROUP:
                return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
        case XFS_DQTYPE_PROJ:
                return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
        }
        ASSERT(0);
        return false;
}

/*
 * Check whether a dquot is under low free space conditions. We assume the quota
 * is enabled and enforced.
 */
static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
{
        int64_t freesp;

        freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
        if (freesp < dqp->q_blk_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
                return true;

        freesp = dqp->q_rtb.hardlimit - dqp->q_rtb.reserved;
        if (freesp < dqp->q_rtb_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
                return true;

        return false;
}

void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);

#define XFS_DQ_IS_LOCKED(dqp)   (mutex_is_locked(&((dqp)->q_qlock)))
#define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->q_flags & XFS_DQFLAG_DIRTY)

void            xfs_qm_dqdestroy(struct xfs_dquot *dqp);
int             xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf *bp);
void            xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);
void            xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
void            xfs_qm_adjust_dqlimits(struct xfs_dquot *d);
xfs_dqid_t      xfs_qm_id_for_quotatype(struct xfs_inode *ip,
                                xfs_dqtype_t type);
int             xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
                                xfs_dqtype_t type, bool can_alloc,
                                struct xfs_dquot **dqpp);
int             xfs_qm_dqget_inode(struct xfs_inode *ip, xfs_dqtype_t type,
                                bool can_alloc, struct xfs_dquot **dqpp);
int             xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
                                xfs_dqtype_t type, struct xfs_dquot **dqpp);
int             xfs_qm_dqget_uncached(struct xfs_mount *mp,
                                xfs_dqid_t id, xfs_dqtype_t type,
                                struct xfs_dquot **dqpp);

void            xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
void            xfs_dqlockn(struct xfs_dqtrx *q);

void            xfs_dquot_set_prealloc_limits(struct xfs_dquot *);

int xfs_dquot_attach_buf(struct xfs_trans *tp, struct xfs_dquot *dqp);
int xfs_dquot_use_attached_buf(struct xfs_dquot *dqp, struct xfs_buf **bpp);
void xfs_dquot_detach_buf(struct xfs_dquot *dqp);

static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
{
        lockref_get(&dqp->q_lockref);
        return dqp;
}

time64_t xfs_dquot_set_timeout(struct xfs_mount *mp, time64_t timeout);
time64_t xfs_dquot_set_grace_period(time64_t grace);

void xfs_qm_init_dquot_blk(struct xfs_trans *tp, xfs_dqid_t id, xfs_dqtype_t
                type, struct xfs_buf *bp);

#endif /* __XFS_DQUOT_H__ */