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 /*
  36  * The incore dquot structure
  37  */
  38 typedef struct xfs_dquot {
  39         uint             dq_flags;      /* various flags (XFS_DQ_*) */
  40         struct list_head q_lru;         /* global free list of dquots */
  41         struct xfs_mount*q_mount;       /* filesystem this relates to */
  42         struct xfs_trans*q_transp;      /* trans this belongs to currently */
  43         uint             q_nrefs;       /* # active refs from inodes */
  44         xfs_daddr_t      q_blkno;       /* blkno of dquot buffer */
  45         int              q_bufoffset;   /* off of dq in buffer (# dquots) */
  46         xfs_fileoff_t    q_fileoffset;  /* offset in quotas file */
  47
  48         struct xfs_dquot*q_gdquot;      /* group dquot, hint only */
  49         xfs_disk_dquot_t q_core;        /* actual usage & quotas */
  50         xfs_dq_logitem_t q_logitem;     /* dquot log item */
  51         xfs_qcnt_t       q_res_bcount;  /* total regular nblks used+reserved */
  52         xfs_qcnt_t       q_res_icount;  /* total inos allocd+reserved */
  53         xfs_qcnt_t       q_res_rtbcount;/* total realtime blks used+reserved */
  54         struct mutex     q_qlock;       /* quota lock */
  55         struct completion q_flush;      /* flush completion queue */
  56         atomic_t          q_pincount;   /* dquot pin count */
  57         wait_queue_head_t q_pinwait;    /* dquot pinning wait queue */
  58 } xfs_dquot_t;
  59
  60 /*
  61  * Lock hierarchy for q_qlock:
  62  *      XFS_QLOCK_NORMAL is the implicit default,
  63  *      XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
  64  */
  65 enum {
  66         XFS_QLOCK_NORMAL = 0,
  67         XFS_QLOCK_NESTED,
  68 };
  69
  70 /*
  71  * Manage the q_flush completion queue embedded in the dquot.  This completion
  72  * queue synchronizes processes attempting to flush the in-core dquot back to
  73  * disk.
  74  */
  75 static inline void xfs_dqflock(xfs_dquot_t *dqp)
  76 {
  77         wait_for_completion(&dqp->q_flush);
  78 }
  79
  80 static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
  81 {
  82         return try_wait_for_completion(&dqp->q_flush);
  83 }
  84
  85 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
  86 {
  87         complete(&dqp->q_flush);
  88 }
  89
  90 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
  91 {
  92         return mutex_trylock(&dqp->q_qlock);
  93 }
  94
  95 static inline void xfs_dqlock(struct xfs_dquot *dqp)
  96 {
  97         mutex_lock(&dqp->q_qlock);
  98 }
  99
 100 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
 101 {
 102         mutex_unlock(&dqp->q_qlock);
 103 }
 104
 105 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
 106 {
 107         switch (type & XFS_DQ_ALLTYPES) {
 108         case XFS_DQ_USER:
 109                 return XFS_IS_UQUOTA_ON(mp);
 110         case XFS_DQ_GROUP:
 111         case XFS_DQ_PROJ:
 112                 return XFS_IS_OQUOTA_ON(mp);
 113         default:
 114                 return 0;
 115         }
 116 }
 117
 118 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
 119 {
 120         switch (type & XFS_DQ_ALLTYPES) {
 121         case XFS_DQ_USER:
 122                 return ip->i_udquot;
 123         case XFS_DQ_GROUP:
 124         case XFS_DQ_PROJ:
 125                 return ip->i_gdquot;
 126         default:
 127                 return NULL;
 128         }
 129 }
 130
 131 #define XFS_DQ_IS_LOCKED(dqp)   (mutex_is_locked(&((dqp)->q_qlock)))
 132 #define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->dq_flags & XFS_DQ_DIRTY)
 133 #define XFS_QM_ISUDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_USER)
 134 #define XFS_QM_ISPDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_PROJ)
 135 #define XFS_QM_ISGDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_GROUP)
 136 #define XFS_DQ_TO_QINF(dqp)     ((dqp)->q_mount->m_quotainfo)
 137 #define XFS_DQ_TO_QIP(dqp)      (XFS_QM_ISUDQ(dqp) ? \
 138                                  XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
 139                                  XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
 140
 141 extern int              xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
 142                                         uint, struct xfs_dquot  **);
 143 extern void             xfs_qm_dqdestroy(xfs_dquot_t *);
 144 extern int              xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
 145 extern void             xfs_qm_dqunpin_wait(xfs_dquot_t *);
 146 extern void             xfs_qm_adjust_dqtimers(xfs_mount_t *,
 147                                         xfs_disk_dquot_t *);
 148 extern void             xfs_qm_adjust_dqlimits(xfs_mount_t *,
 149                                         xfs_disk_dquot_t *);
 150 extern int              xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
 151                                         xfs_dqid_t, uint, uint, xfs_dquot_t **);
 152 extern void             xfs_qm_dqput(xfs_dquot_t *);
 153
 154 extern void             xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
 155
 156 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
 157 {
 158         xfs_dqlock(dqp);
 159         dqp->q_nrefs++;
 160         xfs_dqunlock(dqp);
 161         return dqp;
 162 }
 163
 164 extern const struct xfs_buf_ops xfs_dquot_buf_ops;
 165
 166 #endif /* __XFS_DQUOT_H__ */