1 /*
2  * Copyright (c) 2000-2002 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 /*
117  * Quota Accounting flags
118  */
119 #define XFS_ALL_QUOTA_ACCT	(XFS_UQUOTA_ACCT | XFS_GQUOTA_ACCT)
120 #define XFS_ALL_QUOTA_ENFD	(XFS_UQUOTA_ENFD | XFS_GQUOTA_ENFD)
121 #define XFS_ALL_QUOTA_CHKD	(XFS_UQUOTA_CHKD | XFS_GQUOTA_CHKD)
122 #define XFS_ALL_QUOTA_ACTV	(XFS_UQUOTA_ACTIVE | XFS_GQUOTA_ACTIVE)
123 #define XFS_ALL_QUOTA_ACCT_ENFD (XFS_UQUOTA_ACCT|XFS_UQUOTA_ENFD|\
124 				 XFS_GQUOTA_ACCT|XFS_GQUOTA_ENFD)
125 
126 #define XFS_IS_QUOTA_RUNNING(mp)  ((mp)->m_qflags & XFS_ALL_QUOTA_ACCT)
127 #define XFS_IS_UQUOTA_RUNNING(mp) ((mp)->m_qflags & XFS_UQUOTA_ACCT)
128 #define XFS_IS_GQUOTA_RUNNING(mp) ((mp)->m_qflags & XFS_GQUOTA_ACCT)
129 
130 /*
131  * Quota Limit Enforcement flags
132  */
133 #define XFS_IS_QUOTA_ENFORCED(mp)	((mp)->m_qflags & XFS_ALL_QUOTA_ENFD)
134 #define XFS_IS_UQUOTA_ENFORCED(mp)	((mp)->m_qflags & XFS_UQUOTA_ENFD)
135 #define XFS_IS_GQUOTA_ENFORCED(mp)	((mp)->m_qflags & XFS_GQUOTA_ENFD)
136 
137 #ifdef DEBUG
138 static inline int
XFS_DQ_IS_LOCKED(xfs_dquot_t * dqp)139 XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp)
140 {
141 	if (mutex_trylock(&dqp->q_qlock)) {
142 		mutex_unlock(&dqp->q_qlock);
143 		return 0;
144 	}
145 	return 1;
146 }
147 #endif
148 
149 
150 /*
151  * The following three routines simply manage the q_flock
152  * semaphore embedded in the dquot.  This semaphore synchronizes
153  * processes attempting to flush the in-core dquot back to disk.
154  */
155 #define xfs_dqflock(dqp)	 { psema(&((dqp)->q_flock), PINOD | PRECALC);\
156 				   (dqp)->dq_flags |= XFS_DQ_FLOCKED; }
157 #define xfs_dqfunlock(dqp)	 { ASSERT(valusema(&((dqp)->q_flock)) <= 0); \
158 				   vsema(&((dqp)->q_flock)); \
159 				   (dqp)->dq_flags &= ~(XFS_DQ_FLOCKED); }
160 
161 #define XFS_DQ_PINLOCK(dqp)	   mutex_spinlock( \
162 				     &(XFS_DQ_TO_QINF(dqp)->qi_pinlock))
163 #define XFS_DQ_PINUNLOCK(dqp, s)   mutex_spinunlock( \
164 				     &(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s)
165 
166 #define XFS_DQ_IS_FLUSH_LOCKED(dqp) (valusema(&((dqp)->q_flock)) <= 0)
167 #define XFS_DQ_IS_ON_FREELIST(dqp)  ((dqp)->dq_flnext != (dqp))
168 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
169 #define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
170 #define XFS_DQ_TO_QINF(dqp)	((dqp)->q_mount->m_quotainfo)
171 #define XFS_DQ_TO_QIP(dqp)	(XFS_QM_ISUDQ(dqp) ? \
172 				 XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
173 				 XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
174 
175 #define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
176 				     (XFS_IS_UQUOTA_ON((d)->q_mount)) : \
177 				     (XFS_IS_GQUOTA_ON((d)->q_mount))))
178 
179 #ifdef XFS_DQUOT_TRACE
180 /*
181  * Dquot Tracing stuff.
182  */
183 #define DQUOT_TRACE_SIZE	64
184 #define DQUOT_KTRACE_ENTRY	1
185 
186 extern void		__xfs_dqtrace_entry(xfs_dquot_t *dqp, char *func,
187 					    void *, xfs_inode_t *);
188 #define xfs_dqtrace_entry_ino(a,b,ip) \
189 		__xfs_dqtrace_entry((a), (b), (void*)__return_address, (ip))
190 #define xfs_dqtrace_entry(a,b) \
191 		__xfs_dqtrace_entry((a), (b), (void*)__return_address, NULL)
192 #else
193 #define xfs_dqtrace_entry(a,b)
194 #define xfs_dqtrace_entry_ino(a,b,ip)
195 #endif
196 
197 #ifdef QUOTADEBUG
198 extern void		xfs_qm_dqprint(xfs_dquot_t *);
199 #else
200 #define xfs_qm_dqprint(a)
201 #endif
202 
203 extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
204 extern int		xfs_qm_dqflush(xfs_dquot_t *, uint);
205 extern int		xfs_qm_dqpurge(xfs_dquot_t *, uint);
206 extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
207 extern int		xfs_qm_dqlock_nowait(xfs_dquot_t *);
208 extern int		xfs_qm_dqflock_nowait(xfs_dquot_t *);
209 extern void		xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
210 extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
211 					xfs_disk_dquot_t *);
212 extern void		xfs_qm_adjust_dqlimits(xfs_mount_t *,
213 					xfs_disk_dquot_t *);
214 extern int		xfs_qm_dqwarn(xfs_disk_dquot_t *, uint);
215 extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
216 					xfs_dqid_t, uint, uint, xfs_dquot_t **);
217 extern void		xfs_qm_dqput(xfs_dquot_t *);
218 extern void		xfs_qm_dqrele(xfs_dquot_t *);
219 extern void		xfs_dqlock(xfs_dquot_t *);
220 extern void		xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
221 extern void		xfs_dqunlock(xfs_dquot_t *);
222 extern void		xfs_dqunlock_nonotify(xfs_dquot_t *);
223 
224 #endif /* __XFS_DQUOT_H__ */
225