fs/xfs/xfs_dquot.h

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_DQUOT_H__
  19 #define __XFS_DQUOT_H__
  20
  21 /*
  22  * Dquots are structures that hold quota information about a user or a group,
  23  * much like inodes are for files. In fact, dquots share many characteristics
  24  * with inodes. However, dquots can also be a centralized resource, relative
  25  * to a collection of inodes. In this respect, dquots share some characteristics
  26  * of the superblock.
  27  * XFS dquots exploit both those in its algorithms. They make every attempt
  28  * to not be a bottleneck when quotas are on and have minimal impact, if any,
  29  * when quotas are off.
  30  */
  31
  32 struct xfs_mount;
  33 struct xfs_trans;
  34
  35 enum {
  36         XFS_QLOWSP_1_PCNT = 0,
  37         XFS_QLOWSP_3_PCNT,
  38         XFS_QLOWSP_5_PCNT,
  39         XFS_QLOWSP_MAX
  40 };
  41
  42 /*
  43  * The incore dquot structure
  44  */
  45 typedef struct xfs_dquot {
  46         uint             dq_flags;      /* various flags (XFS_DQ_*) */
  47         struct list_head q_lru;         /* global free list of dquots */
  48         struct xfs_mount*q_mount;       /* filesystem this relates to */
  49         struct xfs_trans*q_transp;      /* trans this belongs to currently */
  50         uint             q_nrefs;       /* # active refs from inodes */
  51         xfs_daddr_t      q_blkno;       /* blkno of dquot buffer */
  52         int              q_bufoffset;   /* off of dq in buffer (# dquots) */
  53         xfs_fileoff_t    q_fileoffset;  /* offset in quotas file */
  54
  55         xfs_disk_dquot_t q_core;        /* actual usage & quotas */
  56         xfs_dq_logitem_t q_logitem;     /* dquot log item */
  57         xfs_qcnt_t       q_res_bcount;  /* total regular nblks used+reserved */
  58         xfs_qcnt_t       q_res_icount;  /* total inos allocd+reserved */
  59         xfs_qcnt_t       q_res_rtbcount;/* total realtime blks used+reserved */
  60         xfs_qcnt_t       q_prealloc_lo_wmark;/* prealloc throttle wmark */
  61         xfs_qcnt_t       q_prealloc_hi_wmark;/* prealloc disabled wmark */
  62         int64_t          q_low_space[XFS_QLOWSP_MAX];
  63         struct mutex     q_qlock;       /* quota lock */
  64         struct completion q_flush;      /* flush completion queue */
  65         atomic_t          q_pincount;   /* dquot pin count */
  66         wait_queue_head_t q_pinwait;    /* dquot pinning wait queue */
  67 } xfs_dquot_t;
  68
  69 /*
  70  * Lock hierarchy for q_qlock:
  71  *      XFS_QLOCK_NORMAL is the implicit default,
  72  *      XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
  73  */
  74 enum {
  75         XFS_QLOCK_NORMAL = 0,
  76         XFS_QLOCK_NESTED,
  77 };
  78
  79 /*
  80  * Manage the q_flush completion queue embedded in the dquot.  This completion
  81  * queue synchronizes processes attempting to flush the in-core dquot back to
  82  * disk.
  83  */
  84 static inline void xfs_dqflock(xfs_dquot_t *dqp)
  85 {
  86         wait_for_completion(&dqp->q_flush);
  87 }
  88
  89 static inline bool xfs_dqflock_nowait(xfs_dquot_t *dqp)
  90 {
  91         return try_wait_for_completion(&dqp->q_flush);
  92 }
  93
  94 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
  95 {
  96         complete(&dqp->q_flush);
  97 }
  98
  99 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
 100 {
 101         return mutex_trylock(&dqp->q_qlock);
 102 }
 103
 104 static inline void xfs_dqlock(struct xfs_dquot *dqp)
 105 {
 106         mutex_lock(&dqp->q_qlock);
 107 }
 108
 109 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
 110 {
 111         mutex_unlock(&dqp->q_qlock);
 112 }
 113
 114 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
 115 {
 116         switch (type & XFS_DQ_ALLTYPES) {
 117         case XFS_DQ_USER:
 118                 return XFS_IS_UQUOTA_ON(mp);
 119         case XFS_DQ_GROUP:
 120                 return XFS_IS_GQUOTA_ON(mp);
 121         case XFS_DQ_PROJ:
 122                 return XFS_IS_PQUOTA_ON(mp);
 123         default:
 124                 return 0;
 125         }
 126 }
 127
 128 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
 129 {
 130         switch (type & XFS_DQ_ALLTYPES) {
 131         case XFS_DQ_USER:
 132                 return ip->i_udquot;
 133         case XFS_DQ_GROUP:
 134                 return ip->i_gdquot;
 135         case XFS_DQ_PROJ:
 136                 return ip->i_pdquot;
 137         default:
 138                 return NULL;
 139         }
 140 }
 141
 142 /*
 143  * Check whether a dquot is under low free space conditions. We assume the quota
 144  * is enabled and enforced.
 145  */
 146 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
 147 {
 148         int64_t freesp;
 149
 150         freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
 151         if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
 152                 return true;
 153
 154         return false;
 155 }
 156
 157 #define XFS_DQ_IS_LOCKED(dqp)   (mutex_is_locked(&((dqp)->q_qlock)))
 158 #define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->dq_flags & XFS_DQ_DIRTY)
 159 #define XFS_QM_ISUDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_USER)
 160 #define XFS_QM_ISPDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_PROJ)
 161 #define XFS_QM_ISGDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_GROUP)
 162
 163 extern int              xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
 164                                         uint, struct xfs_dquot  **);
 165 extern void             xfs_qm_dqdestroy(xfs_dquot_t *);
 166 extern int              xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
 167 extern void             xfs_qm_dqunpin_wait(xfs_dquot_t *);
 168 extern void             xfs_qm_adjust_dqtimers(xfs_mount_t *,
 169                                         xfs_disk_dquot_t *);
 170 extern void             xfs_qm_adjust_dqlimits(struct xfs_mount *,
 171                                                struct xfs_dquot *);
 172 extern int              xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
 173                                         xfs_dqid_t, uint, uint, xfs_dquot_t **);
 174 extern void             xfs_qm_dqput(xfs_dquot_t *);
 175
 176 extern void             xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
 177
 178 extern void             xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
 179
 180 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
 181 {
 182         xfs_dqlock(dqp);
 183         dqp->q_nrefs++;
 184         xfs_dqunlock(dqp);
 185         return dqp;
 186 }
 187
 188 #endif /* __XFS_DQUOT_H__ */