xref: /openbmc/linux/fs/xfs/xfs_dquot.h (revision ee8a99bd)
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 enum {
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  */
45 typedef 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 	struct xfs_dquot*q_gdquot;	/* group dquot, hint only */
56 	struct xfs_dquot*q_pdquot;	/* project dquot, hint only */
57 	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
58 	xfs_dq_logitem_t q_logitem;	/* dquot log item */
59 	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
60 	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
61 	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
62 	xfs_qcnt_t	 q_prealloc_lo_wmark;/* prealloc throttle wmark */
63 	xfs_qcnt_t	 q_prealloc_hi_wmark;/* prealloc disabled wmark */
64 	int64_t		 q_low_space[XFS_QLOWSP_MAX];
65 	struct mutex	 q_qlock;	/* quota lock */
66 	struct completion q_flush;	/* flush completion queue */
67 	atomic_t          q_pincount;	/* dquot pin count */
68 	wait_queue_head_t q_pinwait;	/* dquot pinning wait queue */
69 } xfs_dquot_t;
70 
71 /*
72  * Lock hierarchy for q_qlock:
73  *	XFS_QLOCK_NORMAL is the implicit default,
74  * 	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
75  */
76 enum {
77 	XFS_QLOCK_NORMAL = 0,
78 	XFS_QLOCK_NESTED,
79 };
80 
81 /*
82  * Manage the q_flush completion queue embedded in the dquot.  This completion
83  * queue synchronizes processes attempting to flush the in-core dquot back to
84  * disk.
85  */
86 static inline void xfs_dqflock(xfs_dquot_t *dqp)
87 {
88 	wait_for_completion(&dqp->q_flush);
89 }
90 
91 static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
92 {
93 	return try_wait_for_completion(&dqp->q_flush);
94 }
95 
96 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
97 {
98 	complete(&dqp->q_flush);
99 }
100 
101 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
102 {
103 	return mutex_trylock(&dqp->q_qlock);
104 }
105 
106 static inline void xfs_dqlock(struct xfs_dquot *dqp)
107 {
108 	mutex_lock(&dqp->q_qlock);
109 }
110 
111 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
112 {
113 	mutex_unlock(&dqp->q_qlock);
114 }
115 
116 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
117 {
118 	switch (type & XFS_DQ_ALLTYPES) {
119 	case XFS_DQ_USER:
120 		return XFS_IS_UQUOTA_ON(mp);
121 	case XFS_DQ_GROUP:
122 		return XFS_IS_GQUOTA_ON(mp);
123 	case XFS_DQ_PROJ:
124 		return XFS_IS_PQUOTA_ON(mp);
125 	default:
126 		return 0;
127 	}
128 }
129 
130 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
131 {
132 	switch (type & XFS_DQ_ALLTYPES) {
133 	case XFS_DQ_USER:
134 		return ip->i_udquot;
135 	case XFS_DQ_GROUP:
136 		return ip->i_gdquot;
137 	case XFS_DQ_PROJ:
138 		return ip->i_pdquot;
139 	default:
140 		return NULL;
141 	}
142 }
143 
144 #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
145 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
146 #define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
147 #define XFS_QM_ISPDQ(dqp)	((dqp)->dq_flags & XFS_DQ_PROJ)
148 #define XFS_QM_ISGDQ(dqp)	((dqp)->dq_flags & XFS_DQ_GROUP)
149 
150 extern int		xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
151 					uint, struct xfs_dquot	**);
152 extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
153 extern int		xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
154 extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
155 extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
156 					xfs_disk_dquot_t *);
157 extern void		xfs_qm_adjust_dqlimits(struct xfs_mount *,
158 					       struct xfs_dquot *);
159 extern int		xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
160 					xfs_dqid_t, uint, uint, xfs_dquot_t **);
161 extern void		xfs_qm_dqput(xfs_dquot_t *);
162 
163 extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
164 
165 extern void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
166 
167 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
168 {
169 	xfs_dqlock(dqp);
170 	dqp->q_nrefs++;
171 	xfs_dqunlock(dqp);
172 	return dqp;
173 }
174 
175 extern const struct xfs_buf_ops xfs_dquot_buf_ops;
176 
177 #endif /* __XFS_DQUOT_H__ */
178