fs/xfs/quota/xfs_dquot.h

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_DQUOT_H__
  33 #define __XFS_DQUOT_H__
  34
  35 /*
  36  * Dquots are structures that hold quota information about a user or a group,
  37  * much like inodes are for files. In fact, dquots share many characteristics
  38  * with inodes. However, dquots can also be a centralized resource, relative
  39  * to a collection of inodes. In this respect, dquots share some characteristics
  40  * of the superblock.
  41  * XFS dquots exploit both those in its algorithms. They make every attempt
  42  * to not be a bottleneck when quotas are on and have minimal impact, if any,
  43  * when quotas are off.
  44  */
  45
  46 /*
  47  * The hash chain headers (hash buckets)
  48  */
  49 typedef struct xfs_dqhash {
  50         struct xfs_dquot *qh_next;
  51         mutex_t           qh_lock;
  52         uint              qh_version;   /* ever increasing version */
  53         uint              qh_nelems;    /* number of dquots on the list */
  54 } xfs_dqhash_t;
  55
  56 typedef struct xfs_dqlink {
  57         struct xfs_dquot  *ql_next;     /* forward link */
  58         struct xfs_dquot **ql_prevp;    /* pointer to prev ql_next */
  59 } xfs_dqlink_t;
  60
  61 struct xfs_mount;
  62 struct xfs_trans;
  63
  64 /*
  65  * This is the marker which is designed to occupy the first few
  66  * bytes of the xfs_dquot_t structure. Even inside this, the freelist pointers
  67  * must come first.
  68  * This serves as the marker ("sentinel") when we have to restart list
  69  * iterations because of locking considerations.
  70  */
  71 typedef struct xfs_dqmarker {
  72         struct xfs_dquot*dqm_flnext;    /* link to freelist: must be first */
  73         struct xfs_dquot*dqm_flprev;
  74         xfs_dqlink_t     dqm_mplist;    /* link to mount's list of dquots */
  75         xfs_dqlink_t     dqm_hashlist;  /* link to the hash chain */
  76         uint             dqm_flags;     /* various flags (XFS_DQ_*) */
  77 } xfs_dqmarker_t;
  78
  79 /*
  80  * The incore dquot structure
  81  */
  82 typedef struct xfs_dquot {
  83         xfs_dqmarker_t   q_lists;       /* list ptrs, q_flags (marker) */
  84         xfs_dqhash_t    *q_hash;        /* the hashchain header */
  85         struct xfs_mount*q_mount;       /* filesystem this relates to */
  86         struct xfs_trans*q_transp;      /* trans this belongs to currently */
  87         uint             q_nrefs;       /* # active refs from inodes */
  88         xfs_daddr_t      q_blkno;       /* blkno of dquot buffer */
  89         int              q_bufoffset;   /* off of dq in buffer (# dquots) */
  90         xfs_fileoff_t    q_fileoffset;  /* offset in quotas file */
  91
  92         struct xfs_dquot*q_gdquot;      /* group dquot, hint only */
  93         xfs_disk_dquot_t q_core;        /* actual usage & quotas */
  94         xfs_dq_logitem_t q_logitem;     /* dquot log item */
  95         xfs_qcnt_t       q_res_bcount;  /* total regular nblks used+reserved */
  96         xfs_qcnt_t       q_res_icount;  /* total inos allocd+reserved */
  97         xfs_qcnt_t       q_res_rtbcount;/* total realtime blks used+reserved */
  98         mutex_t          q_qlock;       /* quota lock */
  99         sema_t           q_flock;       /* flush lock */
 100         uint             q_pincount;    /* pin count for this dquot */
 101         sv_t             q_pinwait;     /* sync var for pinning */
 102 #ifdef XFS_DQUOT_TRACE
 103         struct ktrace   *q_trace;       /* trace header structure */
 104 #endif
 105 } xfs_dquot_t;
 106
 107
 108 #define dq_flnext       q_lists.dqm_flnext
 109 #define dq_flprev       q_lists.dqm_flprev
 110 #define dq_mplist       q_lists.dqm_mplist
 111 #define dq_hashlist     q_lists.dqm_hashlist
 112 #define dq_flags        q_lists.dqm_flags
 113
 114 #define XFS_DQHOLD(dqp)         ((dqp)->q_nrefs++)
 115
 116 #ifdef DEBUG
 117 static inline int
 118 XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp)
 119 {
 120         if (mutex_trylock(&dqp->q_qlock)) {
 121                 mutex_unlock(&dqp->q_qlock);
 122                 return 0;
 123         }
 124         return 1;
 125 }
 126 #endif
 127
 128
 129 /*
 130  * The following three routines simply manage the q_flock
 131  * semaphore embedded in the dquot.  This semaphore synchronizes
 132  * processes attempting to flush the in-core dquot back to disk.
 133  */
 134 #define xfs_dqflock(dqp)         { psema(&((dqp)->q_flock), PINOD | PRECALC);\
 135                                    (dqp)->dq_flags |= XFS_DQ_FLOCKED; }
 136 #define xfs_dqfunlock(dqp)       { ASSERT(valusema(&((dqp)->q_flock)) <= 0); \
 137                                    vsema(&((dqp)->q_flock)); \
 138                                    (dqp)->dq_flags &= ~(XFS_DQ_FLOCKED); }
 139
 140 #define XFS_DQ_PINLOCK(dqp)        mutex_spinlock( \
 141                                      &(XFS_DQ_TO_QINF(dqp)->qi_pinlock))
 142 #define XFS_DQ_PINUNLOCK(dqp, s)   mutex_spinunlock( \
 143                                      &(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s)
 144
 145 #define XFS_DQ_IS_FLUSH_LOCKED(dqp) (valusema(&((dqp)->q_flock)) <= 0)
 146 #define XFS_DQ_IS_ON_FREELIST(dqp)  ((dqp)->dq_flnext != (dqp))
 147 #define XFS_DQ_IS_DIRTY(dqp)    ((dqp)->dq_flags & XFS_DQ_DIRTY)
 148 #define XFS_QM_ISUDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_USER)
 149 #define XFS_QM_ISPDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_PROJ)
 150 #define XFS_QM_ISGDQ(dqp)       ((dqp)->dq_flags & XFS_DQ_GROUP)
 151 #define XFS_DQ_TO_QINF(dqp)     ((dqp)->q_mount->m_quotainfo)
 152 #define XFS_DQ_TO_QIP(dqp)      (XFS_QM_ISUDQ(dqp) ? \
 153                                  XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
 154                                  XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
 155
 156 #define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
 157                                      (XFS_IS_UQUOTA_ON((d)->q_mount)) : \
 158                                      (XFS_IS_OQUOTA_ON((d)->q_mount))))
 159
 160 #ifdef XFS_DQUOT_TRACE
 161 /*
 162  * Dquot Tracing stuff.
 163  */
 164 #define DQUOT_TRACE_SIZE        64
 165 #define DQUOT_KTRACE_ENTRY      1
 166
 167 extern void             __xfs_dqtrace_entry(xfs_dquot_t *dqp, char *func,
 168                                             void *, xfs_inode_t *);
 169 #define xfs_dqtrace_entry_ino(a,b,ip) \
 170                 __xfs_dqtrace_entry((a), (b), (void*)__return_address, (ip))
 171 #define xfs_dqtrace_entry(a,b) \
 172                 __xfs_dqtrace_entry((a), (b), (void*)__return_address, NULL)
 173 #else
 174 #define xfs_dqtrace_entry(a,b)
 175 #define xfs_dqtrace_entry_ino(a,b,ip)
 176 #endif
 177
 178 #ifdef QUOTADEBUG
 179 extern void             xfs_qm_dqprint(xfs_dquot_t *);
 180 #else
 181 #define xfs_qm_dqprint(a)
 182 #endif
 183
 184 extern void             xfs_qm_dqdestroy(xfs_dquot_t *);
 185 extern int              xfs_qm_dqflush(xfs_dquot_t *, uint);
 186 extern int              xfs_qm_dqpurge(xfs_dquot_t *, uint);
 187 extern void             xfs_qm_dqunpin_wait(xfs_dquot_t *);
 188 extern int              xfs_qm_dqlock_nowait(xfs_dquot_t *);
 189 extern int              xfs_qm_dqflock_nowait(xfs_dquot_t *);
 190 extern void             xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
 191 extern void             xfs_qm_adjust_dqtimers(xfs_mount_t *,
 192                                         xfs_disk_dquot_t *);
 193 extern void             xfs_qm_adjust_dqlimits(xfs_mount_t *,
 194                                         xfs_disk_dquot_t *);
 195 extern int              xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
 196                                         xfs_dqid_t, uint, uint, xfs_dquot_t **);
 197 extern void             xfs_qm_dqput(xfs_dquot_t *);
 198 extern void             xfs_qm_dqrele(xfs_dquot_t *);
 199 extern void             xfs_dqlock(xfs_dquot_t *);
 200 extern void             xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
 201 extern void             xfs_dqunlock(xfs_dquot_t *);
 202 extern void             xfs_dqunlock_nonotify(xfs_dquot_t *);
 203
 204 #endif /* __XFS_DQUOT_H__ */