fs/xfs/xfs_dquot.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6 #ifndef __XFS_DQUOT_H__
   7 #define __XFS_DQUOT_H__
   8
   9 /*
  10  * Dquots are structures that hold quota information about a user or a group,
  11  * much like inodes are for files. In fact, dquots share many characteristics
  12  * with inodes. However, dquots can also be a centralized resource, relative
  13  * to a collection of inodes. In this respect, dquots share some characteristics
  14  * of the superblock.
  15  * XFS dquots exploit both those in its algorithms. They make every attempt
  16  * to not be a bottleneck when quotas are on and have minimal impact, if any,
  17  * when quotas are off.
  18  */
  19
  20 struct xfs_mount;
  21 struct xfs_trans;
  22
  23 enum {
  24         XFS_QLOWSP_1_PCNT = 0,
  25         XFS_QLOWSP_3_PCNT,
  26         XFS_QLOWSP_5_PCNT,
  27         XFS_QLOWSP_MAX
  28 };
  29
  30 /*
  31  * The incore dquot structure
  32  */
  33 typedef struct xfs_dquot {
  34         uint             dq_flags;      /* various flags (XFS_DQ_*) */
  35         struct list_head q_lru;         /* global free list of dquots */
  36         struct xfs_mount*q_mount;       /* filesystem this relates to */
  37         struct xfs_trans*q_transp;      /* trans this belongs to currently */
  38         uint             q_nrefs;       /* # active refs from inodes */
  39         xfs_daddr_t      q_blkno;       /* blkno of dquot buffer */
  40         int              q_bufoffset;   /* off of dq in buffer (# dquots) */
  41         xfs_fileoff_t    q_fileoffset;  /* offset in quotas file */
  42
  43         xfs_disk_dquot_t q_core;        /* actual usage & quotas */
  44         xfs_dq_logitem_t q_logitem;     /* dquot log item */
  45         xfs_qcnt_t       q_res_bcount;  /* total regular nblks used+reserved */
  46         xfs_qcnt_t       q_res_icount;  /* total inos allocd+reserved */
  47         xfs_qcnt_t       q_res_rtbcount;/* total realtime blks used+reserved */
  48         xfs_qcnt_t       q_prealloc_lo_wmark;/* prealloc throttle wmark */
  49         xfs_qcnt_t       q_prealloc_hi_wmark;/* prealloc disabled wmark */
  50         int64_t          q_low_space[XFS_QLOWSP_MAX];
  51         struct mutex     q_qlock;       /* quota lock */
  52         struct completion q_flush;      /* flush completion queue */
  53         atomic_t          q_pincount;   /* dquot pin count */
  54         wait_queue_head_t q_pinwait;    /* dquot pinning wait queue */
  55 } xfs_dquot_t;
  56
  57 /*
  58  * Lock hierarchy for q_qlock:
  59  *      XFS_QLOCK_NORMAL is the implicit default,
  60  *      XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
  61  */
  62 enum {
  63         XFS_QLOCK_NORMAL = 0,
  64         XFS_QLOCK_NESTED,
  65 };
  66
  67 /*
  68  * Manage the q_flush completion queue embedded in the dquot.  This completion
  69  * queue synchronizes processes attempting to flush the in-core dquot back to
  70  * disk.
  71  */
  72 static inline void xfs_dqflock(xfs_dquot_t *dqp)
  73 {
  74         wait_for_completion(&dqp->q_flush);
  75 }
  76
  77 static inline bool xfs_dqflock_nowait(xfs_dquot_t *dqp)
  78 {
  79         return try_wait_for_completion(&dqp->q_flush);
  80 }
  81
  82 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
  83 {
  84         complete(&dqp->q_flush);
  85 }
  86
  87 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
  88 {
  89         return mutex_trylock(&dqp->q_qlock);
  90 }
  91
  92 static inline void xfs_dqlock(struct xfs_dquot *dqp)
  93 {
  94         mutex_lock(&dqp->q_qlock);
  95 }
  96
  97 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
  98 {
  99         mutex_unlock(&dqp->q_qlock);
 100 }
 101
 102 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
 103 {
 104         switch (type & XFS_DQ_ALLTYPES) {
 105         case XFS_DQ_USER:
 106                 return XFS_IS_UQUOTA_ON(mp);
 107         case XFS_DQ_GROUP:
 108                 return XFS_IS_GQUOTA_ON(mp);
 109         case XFS_DQ_PROJ:
 110                 return XFS_IS_PQUOTA_ON(mp);
 111         default:
 112                 return 0;
 113         }
 114 }
 115
 116 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
 117 {
 118         switch (type & XFS_DQ_ALLTYPES) {
 119         case XFS_DQ_USER:
 120                 return ip->i_udquot;
 121         case XFS_DQ_GROUP:
 122                 return ip->i_gdquot;
 123         case XFS_DQ_PROJ:
 124                 return ip->i_pdquot;
 125         default:
 126                 return NULL;
 127         }
 128 }
 129
 130 /*
 131  * Check whether a dquot is under low free space conditions. We assume the quota
 132  * is enabled and enforced.
 133  */
 134 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
 135 {
 136         int64_t freesp;
 137
 138         freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
 139         if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
 140                 return true;
 141
 142         return false;
 143 }
 144
 145 #define XFS_DQ_IS_LOCKED(dqp)   (mutex_is_locked(&((dqp)->q_qlock)))
 146 #define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->dq_flags & XFS_DQ_DIRTY)
 147 #define XFS_QM_ISUDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_USER)
 148 #define XFS_QM_ISPDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_PROJ)
 149 #define XFS_QM_ISGDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_GROUP)
 150
 151 extern void             xfs_qm_dqdestroy(xfs_dquot_t *);
 152 extern int              xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
 153 extern void             xfs_qm_dqunpin_wait(xfs_dquot_t *);
 154 extern void             xfs_qm_adjust_dqtimers(xfs_mount_t *,
 155                                         xfs_disk_dquot_t *);
 156 extern void             xfs_qm_adjust_dqlimits(struct xfs_mount *,
 157                                                struct xfs_dquot *);
 158 extern xfs_dqid_t       xfs_qm_id_for_quotatype(struct xfs_inode *ip,
 159                                         uint type);
 160 extern int              xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
 161                                         uint type, bool can_alloc,
 162                                         struct xfs_dquot **dqpp);
 163 extern int              xfs_qm_dqget_inode(struct xfs_inode *ip, uint type,
 164                                         bool can_alloc,
 165                                         struct xfs_dquot **dqpp);
 166 extern int              xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
 167                                         uint type, struct xfs_dquot **dqpp);
 168 extern int              xfs_qm_dqget_uncached(struct xfs_mount *mp,
 169                                         xfs_dqid_t id, uint type,
 170                                         struct xfs_dquot **dqpp);
 171 extern void             xfs_qm_dqput(xfs_dquot_t *);
 172
 173 extern void             xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
 174
 175 extern void             xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
 176
 177 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
 178 {
 179         xfs_dqlock(dqp);
 180         dqp->q_nrefs++;
 181         xfs_dqunlock(dqp);
 182         return dqp;
 183 }
 184
 185 typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq, uint dqtype,
 186                 void *priv);
 187 int xfs_qm_dqiterate(struct xfs_mount *mp, uint dqtype,
 188                 xfs_qm_dqiterate_fn iter_fn, void *priv);
 189
 190 #endif /* __XFS_DQUOT_H__ */