summaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_dquot.h
blob: a1d91d8f18027b9e217f07ff8769d9d4a21fe2a1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_DQUOT_H__
#define __XFS_DQUOT_H__

/*
 * Dquots are structures that hold quota information about a user or a group,
 * much like inodes are for files. In fact, dquots share many characteristics
 * with inodes. However, dquots can also be a centralized resource, relative
 * to a collection of inodes. In this respect, dquots share some characteristics
 * of the superblock.
 * XFS dquots exploit both those in its algorithms. They make every attempt
 * to not be a bottleneck when quotas are on and have minimal impact, if any,
 * when quotas are off.
 */

/*
 * The hash chain headers (hash buckets)
 */
typedef struct xfs_dqhash {
	struct list_head  qh_list;
	struct mutex	  qh_lock;
	uint		  qh_version;	/* ever increasing version */
	uint		  qh_nelems;	/* number of dquots on the list */
} xfs_dqhash_t;

struct xfs_mount;
struct xfs_trans;

/*
 * The incore dquot structure
 */
typedef struct xfs_dquot {
	uint		 dq_flags;	/* various flags (XFS_DQ_*) */
	struct list_head q_freelist;	/* global free list of dquots */
	struct list_head q_mplist;	/* mount's list of dquots */
	struct list_head q_hashlist;	/* gloabl hash list of dquots */
	xfs_dqhash_t	*q_hash;	/* the hashchain header */
	struct xfs_mount*q_mount;	/* filesystem this relates to */
	struct xfs_trans*q_transp;	/* trans this belongs to currently */
	uint		 q_nrefs;	/* # active refs from inodes */
	xfs_daddr_t	 q_blkno;	/* blkno of dquot buffer */
	int		 q_bufoffset;	/* off of dq in buffer (# dquots) */
	xfs_fileoff_t	 q_fileoffset;	/* offset in quotas file */

	struct xfs_dquot*q_gdquot;	/* group dquot, hint only */
	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
	xfs_dq_logitem_t q_logitem;	/* dquot log item */
	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
	struct mutex	 q_qlock;	/* quota lock */
	struct completion q_flush;	/* flush completion queue */
	atomic_t          q_pincount;	/* dquot pin count */
	wait_queue_head_t q_pinwait;	/* dquot pinning wait queue */
} xfs_dquot_t;

/*
 * Lock hierarchy for q_qlock:
 *	XFS_QLOCK_NORMAL is the implicit default,
 * 	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
 */
enum {
	XFS_QLOCK_NORMAL = 0,
	XFS_QLOCK_NESTED,
};

/*
 * Manage the q_flush completion queue embedded in the dquot.  This completion
 * queue synchronizes processes attempting to flush the in-core dquot back to
 * disk.
 */
static inline void xfs_dqflock(xfs_dquot_t *dqp)
{
	wait_for_completion(&dqp->q_flush);
}

static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
{
	return try_wait_for_completion(&dqp->q_flush);
}

static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
{
	complete(&dqp->q_flush);
}

static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
{
	return mutex_trylock(&dqp->q_qlock);
}

static inline void xfs_dqlock(struct xfs_dquot *dqp)
{
	mutex_lock(&dqp->q_qlock);
}

static inline void xfs_dqunlock_nonotify(struct xfs_dquot *dqp)
{
	mutex_unlock(&dqp->q_qlock);
}

#define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
#define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
#define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
#define XFS_QM_ISPDQ(dqp)	((dqp)->dq_flags & XFS_DQ_PROJ)
#define XFS_QM_ISGDQ(dqp)	((dqp)->dq_flags & XFS_DQ_GROUP)
#define XFS_DQ_TO_QINF(dqp)	((dqp)->q_mount->m_quotainfo)
#define XFS_DQ_TO_QIP(dqp)	(XFS_QM_ISUDQ(dqp) ? \
				 XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
				 XFS_DQ_TO_QINF(dqp)->qi_gquotaip)

#define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
				     (XFS_IS_UQUOTA_ON((d)->q_mount)) : \
				     (XFS_IS_OQUOTA_ON((d)->q_mount))))

extern int		xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
					uint, struct xfs_dquot	**);
extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
extern int		xfs_qm_dqflush(xfs_dquot_t *, uint);
extern void		xfs_qm_dqpurge(xfs_dquot_t *);
extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
					xfs_disk_dquot_t *);
extern void		xfs_qm_adjust_dqlimits(xfs_mount_t *,
					xfs_disk_dquot_t *);
extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
					xfs_dqid_t, uint, uint, xfs_dquot_t **);
extern void		xfs_qm_dqput(xfs_dquot_t *);

extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
extern void		xfs_dqunlock(struct xfs_dquot *);
extern void		xfs_dqflock_pushbuf_wait(struct xfs_dquot *dqp);

static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
{
	xfs_dqlock(dqp);
	dqp->q_nrefs++;
	xfs_dqunlock(dqp);
	return dqp;
}

#endif /* __XFS_DQUOT_H__ */
OpenPOWER on IntegriCloud