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/*
33 * The hash chain headers (hash buckets)
34 */
35typedef struct xfs_dqhash {
36	struct xfs_dquot *qh_next;
37	mutex_t		  qh_lock;
38	uint		  qh_version;	/* ever increasing version */
39	uint		  qh_nelems;	/* number of dquots on the list */
40} xfs_dqhash_t;
41
42typedef struct xfs_dqlink {
43	struct xfs_dquot  *ql_next;	/* forward link */
44	struct xfs_dquot **ql_prevp;	/* pointer to prev ql_next */
45} xfs_dqlink_t;
46
47struct xfs_mount;
48struct xfs_trans;
49
50/*
51 * This is the marker which is designed to occupy the first few
52 * bytes of the xfs_dquot_t structure. Even inside this, the freelist pointers
53 * must come first.
54 * This serves as the marker ("sentinel") when we have to restart list
55 * iterations because of locking considerations.
56 */
57typedef struct xfs_dqmarker {
58	struct xfs_dquot*dqm_flnext;	/* link to freelist: must be first */
59	struct xfs_dquot*dqm_flprev;
60	xfs_dqlink_t	 dqm_mplist;	/* link to mount's list of dquots */
61	xfs_dqlink_t	 dqm_hashlist;	/* link to the hash chain */
62	uint		 dqm_flags;	/* various flags (XFS_DQ_*) */
63} xfs_dqmarker_t;
64
65/*
66 * The incore dquot structure
67 */
68typedef struct xfs_dquot {
69	xfs_dqmarker_t	 q_lists;	/* list ptrs, q_flags (marker) */
70	xfs_dqhash_t	*q_hash;	/* the hashchain header */
71	struct xfs_mount*q_mount;	/* filesystem this relates to */
72	struct xfs_trans*q_transp;	/* trans this belongs to currently */
73	uint		 q_nrefs;	/* # active refs from inodes */
74	xfs_daddr_t	 q_blkno;	/* blkno of dquot buffer */
75	int		 q_bufoffset;	/* off of dq in buffer (# dquots) */
76	xfs_fileoff_t	 q_fileoffset;	/* offset in quotas file */
77
78	struct xfs_dquot*q_gdquot;	/* group dquot, hint only */
79	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
80	xfs_dq_logitem_t q_logitem;	/* dquot log item */
81	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
82	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
83	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
84	mutex_t		 q_qlock;	/* quota lock */
85	sema_t		 q_flock;	/* flush lock */
86	uint		 q_pincount;	/* pin count for this dquot */
87	sv_t		 q_pinwait;	/* sync var for pinning */
88#ifdef XFS_DQUOT_TRACE
89	struct ktrace	*q_trace;	/* trace header structure */
90#endif
91} xfs_dquot_t;
92
93
94#define dq_flnext	q_lists.dqm_flnext
95#define dq_flprev	q_lists.dqm_flprev
96#define dq_mplist	q_lists.dqm_mplist
97#define dq_hashlist	q_lists.dqm_hashlist
98#define dq_flags	q_lists.dqm_flags
99
100#define XFS_DQHOLD(dqp)		((dqp)->q_nrefs++)
101
102#ifdef DEBUG
103static inline int
104XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp)
105{
106	if (mutex_trylock(&dqp->q_qlock)) {
107		mutex_unlock(&dqp->q_qlock);
108		return 0;
109	}
110	return 1;
111}
112#endif
113
114
115/*
116 * The following three routines simply manage the q_flock
117 * semaphore embedded in the dquot.  This semaphore synchronizes
118 * processes attempting to flush the in-core dquot back to disk.
119 */
120#define xfs_dqflock(dqp)	 { psema(&((dqp)->q_flock), PINOD | PRECALC);\
121				   (dqp)->dq_flags |= XFS_DQ_FLOCKED; }
122#define xfs_dqfunlock(dqp)	 { ASSERT(issemalocked(&((dqp)->q_flock))); \
123				   vsema(&((dqp)->q_flock)); \
124				   (dqp)->dq_flags &= ~(XFS_DQ_FLOCKED); }
125
126#define XFS_DQ_PINLOCK(dqp)	   mutex_spinlock( \
127				     &(XFS_DQ_TO_QINF(dqp)->qi_pinlock))
128#define XFS_DQ_PINUNLOCK(dqp, s)   mutex_spinunlock( \
129				     &(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s)
130
131#define XFS_DQ_IS_FLUSH_LOCKED(dqp) (issemalocked(&((dqp)->q_flock)))
132#define XFS_DQ_IS_ON_FREELIST(dqp)  ((dqp)->dq_flnext != (dqp))
133#define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
134#define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
135#define XFS_QM_ISPDQ(dqp)	((dqp)->dq_flags & XFS_DQ_PROJ)
136#define XFS_QM_ISGDQ(dqp)	((dqp)->dq_flags & XFS_DQ_GROUP)
137#define XFS_DQ_TO_QINF(dqp)	((dqp)->q_mount->m_quotainfo)
138#define XFS_DQ_TO_QIP(dqp)	(XFS_QM_ISUDQ(dqp) ? \
139				 XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
140				 XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
141
142#define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
143				     (XFS_IS_UQUOTA_ON((d)->q_mount)) : \
144				     (XFS_IS_OQUOTA_ON((d)->q_mount))))
145
146#ifdef XFS_DQUOT_TRACE
147/*
148 * Dquot Tracing stuff.
149 */
150#define DQUOT_TRACE_SIZE	64
151#define DQUOT_KTRACE_ENTRY	1
152
153extern void		__xfs_dqtrace_entry(xfs_dquot_t *dqp, char *func,
154					    void *, xfs_inode_t *);
155#define xfs_dqtrace_entry_ino(a,b,ip) \
156		__xfs_dqtrace_entry((a), (b), (void*)__return_address, (ip))
157#define xfs_dqtrace_entry(a,b) \
158		__xfs_dqtrace_entry((a), (b), (void*)__return_address, NULL)
159#else
160#define xfs_dqtrace_entry(a,b)
161#define xfs_dqtrace_entry_ino(a,b,ip)
162#endif
163
164#ifdef QUOTADEBUG
165extern void		xfs_qm_dqprint(xfs_dquot_t *);
166#else
167#define xfs_qm_dqprint(a)
168#endif
169
170extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
171extern int		xfs_qm_dqflush(xfs_dquot_t *, uint);
172extern int		xfs_qm_dqpurge(xfs_dquot_t *, uint);
173extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
174extern int		xfs_qm_dqlock_nowait(xfs_dquot_t *);
175extern int		xfs_qm_dqflock_nowait(xfs_dquot_t *);
176extern void		xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
177extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
178					xfs_disk_dquot_t *);
179extern void		xfs_qm_adjust_dqlimits(xfs_mount_t *,
180					xfs_disk_dquot_t *);
181extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
182					xfs_dqid_t, uint, uint, xfs_dquot_t **);
183extern void		xfs_qm_dqput(xfs_dquot_t *);
184extern void		xfs_qm_dqrele(xfs_dquot_t *);
185extern void		xfs_dqlock(xfs_dquot_t *);
186extern void		xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
187extern void		xfs_dqunlock(xfs_dquot_t *);
188extern void		xfs_dqunlock_nonotify(xfs_dquot_t *);
189
190#endif /* __XFS_DQUOT_H__ */
191