xref: /openbmc/linux/fs/xfs/xfs_dquot.h (revision f9a82c48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #ifndef __XFS_DQUOT_H__
7 #define __XFS_DQUOT_H__
8 
9 /*
10  * Dquots are structures that hold quota information about a user or a group,
11  * much like inodes are for files. In fact, dquots share many characteristics
12  * with inodes. However, dquots can also be a centralized resource, relative
13  * to a collection of inodes. In this respect, dquots share some characteristics
14  * of the superblock.
15  * XFS dquots exploit both those in its algorithms. They make every attempt
16  * to not be a bottleneck when quotas are on and have minimal impact, if any,
17  * when quotas are off.
18  */
19 
20 struct xfs_mount;
21 struct xfs_trans;
22 
23 enum {
24 	XFS_QLOWSP_1_PCNT = 0,
25 	XFS_QLOWSP_3_PCNT,
26 	XFS_QLOWSP_5_PCNT,
27 	XFS_QLOWSP_MAX
28 };
29 
30 /*
31  * The incore dquot structure
32  */
33 typedef struct xfs_dquot {
34 	uint		 dq_flags;	/* various flags (XFS_DQ_*) */
35 	struct list_head q_lru;		/* global free list of dquots */
36 	struct xfs_mount*q_mount;	/* filesystem this relates to */
37 	struct xfs_trans*q_transp;	/* trans this belongs to currently */
38 	uint		 q_nrefs;	/* # active refs from inodes */
39 	xfs_daddr_t	 q_blkno;	/* blkno of dquot buffer */
40 	int		 q_bufoffset;	/* off of dq in buffer (# dquots) */
41 	xfs_fileoff_t	 q_fileoffset;	/* offset in quotas file */
42 
43 	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
44 	xfs_dq_logitem_t q_logitem;	/* dquot log item */
45 	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
46 	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
47 	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
48 	xfs_qcnt_t	 q_prealloc_lo_wmark;/* prealloc throttle wmark */
49 	xfs_qcnt_t	 q_prealloc_hi_wmark;/* prealloc disabled wmark */
50 	int64_t		 q_low_space[XFS_QLOWSP_MAX];
51 	struct mutex	 q_qlock;	/* quota lock */
52 	struct completion q_flush;	/* flush completion queue */
53 	atomic_t          q_pincount;	/* dquot pin count */
54 	wait_queue_head_t q_pinwait;	/* dquot pinning wait queue */
55 } xfs_dquot_t;
56 
57 /*
58  * Lock hierarchy for q_qlock:
59  *	XFS_QLOCK_NORMAL is the implicit default,
60  * 	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
61  */
62 enum {
63 	XFS_QLOCK_NORMAL = 0,
64 	XFS_QLOCK_NESTED,
65 };
66 
67 /*
68  * Manage the q_flush completion queue embedded in the dquot.  This completion
69  * queue synchronizes processes attempting to flush the in-core dquot back to
70  * disk.
71  */
72 static inline void xfs_dqflock(xfs_dquot_t *dqp)
73 {
74 	wait_for_completion(&dqp->q_flush);
75 }
76 
77 static inline bool xfs_dqflock_nowait(xfs_dquot_t *dqp)
78 {
79 	return try_wait_for_completion(&dqp->q_flush);
80 }
81 
82 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
83 {
84 	complete(&dqp->q_flush);
85 }
86 
87 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
88 {
89 	return mutex_trylock(&dqp->q_qlock);
90 }
91 
92 static inline void xfs_dqlock(struct xfs_dquot *dqp)
93 {
94 	mutex_lock(&dqp->q_qlock);
95 }
96 
97 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
98 {
99 	mutex_unlock(&dqp->q_qlock);
100 }
101 
102 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
103 {
104 	switch (type & XFS_DQ_ALLTYPES) {
105 	case XFS_DQ_USER:
106 		return XFS_IS_UQUOTA_ON(mp);
107 	case XFS_DQ_GROUP:
108 		return XFS_IS_GQUOTA_ON(mp);
109 	case XFS_DQ_PROJ:
110 		return XFS_IS_PQUOTA_ON(mp);
111 	default:
112 		return 0;
113 	}
114 }
115 
116 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
117 {
118 	switch (type & XFS_DQ_ALLTYPES) {
119 	case XFS_DQ_USER:
120 		return ip->i_udquot;
121 	case XFS_DQ_GROUP:
122 		return ip->i_gdquot;
123 	case XFS_DQ_PROJ:
124 		return ip->i_pdquot;
125 	default:
126 		return NULL;
127 	}
128 }
129 
130 /*
131  * Check whether a dquot is under low free space conditions. We assume the quota
132  * is enabled and enforced.
133  */
134 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
135 {
136 	int64_t freesp;
137 
138 	freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
139 	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
140 		return true;
141 
142 	return false;
143 }
144 
145 #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
146 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
147 #define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)
148 #define XFS_QM_ISPDQ(dqp)	((dqp)->dq_flags & XFS_DQ_PROJ)
149 #define XFS_QM_ISGDQ(dqp)	((dqp)->dq_flags & XFS_DQ_GROUP)
150 
151 extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
152 extern int		xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
153 extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
154 extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
155 					xfs_disk_dquot_t *);
156 extern void		xfs_qm_adjust_dqlimits(struct xfs_mount *,
157 					       struct xfs_dquot *);
158 extern xfs_dqid_t	xfs_qm_id_for_quotatype(struct xfs_inode *ip,
159 					uint type);
160 extern int		xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
161 					uint type, bool can_alloc,
162 					struct xfs_dquot **dqpp);
163 extern int		xfs_qm_dqget_inode(struct xfs_inode *ip, uint type,
164 					bool can_alloc,
165 					struct xfs_dquot **dqpp);
166 extern int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
167 					uint type, struct xfs_dquot **dqpp);
168 extern int		xfs_qm_dqget_uncached(struct xfs_mount *mp,
169 					xfs_dqid_t id, uint type,
170 					struct xfs_dquot **dqpp);
171 extern void		xfs_qm_dqput(xfs_dquot_t *);
172 
173 extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
174 
175 extern void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
176 
177 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
178 {
179 	xfs_dqlock(dqp);
180 	dqp->q_nrefs++;
181 	xfs_dqunlock(dqp);
182 	return dqp;
183 }
184 
185 typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq, uint dqtype,
186 		void *priv);
187 int xfs_qm_dqiterate(struct xfs_mount *mp, uint dqtype,
188 		xfs_qm_dqiterate_fn iter_fn, void *priv);
189 
190 #endif /* __XFS_DQUOT_H__ */
191