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	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
56	xfs_dq_logitem_t q_logitem;	/* dquot log item */
57	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
58	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
59	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
60	xfs_qcnt_t	 q_prealloc_lo_wmark;/* prealloc throttle wmark */
61	xfs_qcnt_t	 q_prealloc_hi_wmark;/* prealloc disabled wmark */
62	int64_t		 q_low_space[XFS_QLOWSP_MAX];
63	struct mutex	 q_qlock;	/* quota lock */
64	struct completion q_flush;	/* flush completion queue */
65	atomic_t          q_pincount;	/* dquot pin count */
66	wait_queue_head_t q_pinwait;	/* dquot pinning wait queue */
67} xfs_dquot_t;
68
69/*
70 * Lock hierarchy for q_qlock:
71 *	XFS_QLOCK_NORMAL is the implicit default,
72 * 	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
73 */
74enum {
75	XFS_QLOCK_NORMAL = 0,
76	XFS_QLOCK_NESTED,
77};
78
79/*
80 * Manage the q_flush completion queue embedded in the dquot.  This completion
81 * queue synchronizes processes attempting to flush the in-core dquot back to
82 * disk.
83 */
84static inline void xfs_dqflock(xfs_dquot_t *dqp)
85{
86	wait_for_completion(&dqp->q_flush);
87}
88
89static inline bool xfs_dqflock_nowait(xfs_dquot_t *dqp)
90{
91	return try_wait_for_completion(&dqp->q_flush);
92}
93
94static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
95{
96	complete(&dqp->q_flush);
97}
98
99static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
100{
101	return mutex_trylock(&dqp->q_qlock);
102}
103
104static inline void xfs_dqlock(struct xfs_dquot *dqp)
105{
106	mutex_lock(&dqp->q_qlock);
107}
108
109static inline void xfs_dqunlock(struct xfs_dquot *dqp)
110{
111	mutex_unlock(&dqp->q_qlock);
112}
113
114static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
115{
116	switch (type & XFS_DQ_ALLTYPES) {
117	case XFS_DQ_USER:
118		return XFS_IS_UQUOTA_ON(mp);
119	case XFS_DQ_GROUP:
120		return XFS_IS_GQUOTA_ON(mp);
121	case XFS_DQ_PROJ:
122		return XFS_IS_PQUOTA_ON(mp);
123	default:
124		return 0;
125	}
126}
127
128static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
129{
130	switch (type & XFS_DQ_ALLTYPES) {
131	case XFS_DQ_USER:
132		return ip->i_udquot;
133	case XFS_DQ_GROUP:
134		return ip->i_gdquot;
135	case XFS_DQ_PROJ:
136		return ip->i_pdquot;
137	default:
138		return NULL;
139	}
140}
141
142/*
143 * Check whether a dquot is under low free space conditions. We assume the quota
144 * is enabled and enforced.
145 */
146static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
147{
148	int64_t freesp;
149
150	freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
151	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
152		return true;
153
154	return false;
155}
156
157#define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
158#define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
159#define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
160#define XFS_QM_ISPDQ(dqp)	((dqp)->dq_flags & XFS_DQ_PROJ)
161#define XFS_QM_ISGDQ(dqp)	((dqp)->dq_flags & XFS_DQ_GROUP)
162
163extern int		xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
164					uint, struct xfs_dquot	**);
165extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
166extern int		xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
167extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
168extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
169					xfs_disk_dquot_t *);
170extern void		xfs_qm_adjust_dqlimits(struct xfs_mount *,
171					       struct xfs_dquot *);
172extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
173					xfs_dqid_t, uint, uint, xfs_dquot_t **);
174extern void		xfs_qm_dqput(xfs_dquot_t *);
175
176extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
177
178extern void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
179
180static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
181{
182	xfs_dqlock(dqp);
183	dqp->q_nrefs++;
184	xfs_dqunlock(dqp);
185	return dqp;
186}
187
188#endif /* __XFS_DQUOT_H__ */
189