linux/fs/xfs/xfs_dquot.h
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   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
  32struct xfs_mount;
  33struct xfs_trans;
  34
  35enum {
  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 */
  45typedef 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        struct xfs_dquot*q_gdquot;      /* group dquot, hint only */
  56        struct xfs_dquot*q_pdquot;      /* project dquot, hint only */
  57        xfs_disk_dquot_t q_core;        /* actual usage & quotas */
  58        xfs_dq_logitem_t q_logitem;     /* dquot log item */
  59        xfs_qcnt_t       q_res_bcount;  /* total regular nblks used+reserved */
  60        xfs_qcnt_t       q_res_icount;  /* total inos allocd+reserved */
  61        xfs_qcnt_t       q_res_rtbcount;/* total realtime blks used+reserved */
  62        xfs_qcnt_t       q_prealloc_lo_wmark;/* prealloc throttle wmark */
  63        xfs_qcnt_t       q_prealloc_hi_wmark;/* prealloc disabled wmark */
  64        int64_t          q_low_space[XFS_QLOWSP_MAX];
  65        struct mutex     q_qlock;       /* quota lock */
  66        struct completion q_flush;      /* flush completion queue */
  67        atomic_t          q_pincount;   /* dquot pin count */
  68        wait_queue_head_t q_pinwait;    /* dquot pinning wait queue */
  69} xfs_dquot_t;
  70
  71/*
  72 * Lock hierarchy for q_qlock:
  73 *      XFS_QLOCK_NORMAL is the implicit default,
  74 *      XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
  75 */
  76enum {
  77        XFS_QLOCK_NORMAL = 0,
  78        XFS_QLOCK_NESTED,
  79};
  80
  81/*
  82 * Manage the q_flush completion queue embedded in the dquot.  This completion
  83 * queue synchronizes processes attempting to flush the in-core dquot back to
  84 * disk.
  85 */
  86static inline void xfs_dqflock(xfs_dquot_t *dqp)
  87{
  88        wait_for_completion(&dqp->q_flush);
  89}
  90
  91static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
  92{
  93        return try_wait_for_completion(&dqp->q_flush);
  94}
  95
  96static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
  97{
  98        complete(&dqp->q_flush);
  99}
 100
 101static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
 102{
 103        return mutex_trylock(&dqp->q_qlock);
 104}
 105
 106static inline void xfs_dqlock(struct xfs_dquot *dqp)
 107{
 108        mutex_lock(&dqp->q_qlock);
 109}
 110
 111static inline void xfs_dqunlock(struct xfs_dquot *dqp)
 112{
 113        mutex_unlock(&dqp->q_qlock);
 114}
 115
 116static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
 117{
 118        switch (type & XFS_DQ_ALLTYPES) {
 119        case XFS_DQ_USER:
 120                return XFS_IS_UQUOTA_ON(mp);
 121        case XFS_DQ_GROUP:
 122                return XFS_IS_GQUOTA_ON(mp);
 123        case XFS_DQ_PROJ:
 124                return XFS_IS_PQUOTA_ON(mp);
 125        default:
 126                return 0;
 127        }
 128}
 129
 130static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
 131{
 132        switch (type & XFS_DQ_ALLTYPES) {
 133        case XFS_DQ_USER:
 134                return ip->i_udquot;
 135        case XFS_DQ_GROUP:
 136                return ip->i_gdquot;
 137        case XFS_DQ_PROJ:
 138                return ip->i_pdquot;
 139        default:
 140                return NULL;
 141        }
 142}
 143
 144#define XFS_DQ_IS_LOCKED(dqp)   (mutex_is_locked(&((dqp)->q_qlock)))
 145#define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->dq_flags & XFS_DQ_DIRTY)
 146#define XFS_QM_ISUDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_USER)
 147#define XFS_QM_ISPDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_PROJ)
 148#define XFS_QM_ISGDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_GROUP)
 149
 150extern int              xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
 151                                        uint, struct xfs_dquot  **);
 152extern void             xfs_qm_dqdestroy(xfs_dquot_t *);
 153extern int              xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
 154extern void             xfs_qm_dqunpin_wait(xfs_dquot_t *);
 155extern void             xfs_qm_adjust_dqtimers(xfs_mount_t *,
 156                                        xfs_disk_dquot_t *);
 157extern void             xfs_qm_adjust_dqlimits(struct xfs_mount *,
 158                                               struct xfs_dquot *);
 159extern int              xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
 160                                        xfs_dqid_t, uint, uint, xfs_dquot_t **);
 161extern void             xfs_qm_dqput(xfs_dquot_t *);
 162
 163extern void             xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
 164
 165extern void             xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
 166
 167static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
 168{
 169        xfs_dqlock(dqp);
 170        dqp->q_nrefs++;
 171        xfs_dqunlock(dqp);
 172        return dqp;
 173}
 174
 175extern const struct xfs_buf_ops xfs_dquot_buf_ops;
 176
 177#endif /* __XFS_DQUOT_H__ */
 178
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