xref: /linux/fs/xfs/xfs_dquot.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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__ */
167