xref: /openbmc/linux/fs/xfs/xfs_dquot.h (revision 5e012745)
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 	uint		 q_nrefs;	/* # active refs from inodes */
38 	xfs_daddr_t	 q_blkno;	/* blkno of dquot buffer */
39 	int		 q_bufoffset;	/* off of dq in buffer (# dquots) */
40 	xfs_fileoff_t	 q_fileoffset;	/* offset in quotas file */
41 
42 	xfs_disk_dquot_t q_core;	/* actual usage & quotas */
43 	xfs_dq_logitem_t q_logitem;	/* dquot log item */
44 	xfs_qcnt_t	 q_res_bcount;	/* total regular nblks used+reserved */
45 	xfs_qcnt_t	 q_res_icount;	/* total inos allocd+reserved */
46 	xfs_qcnt_t	 q_res_rtbcount;/* total realtime blks used+reserved */
47 	xfs_qcnt_t	 q_prealloc_lo_wmark;/* prealloc throttle wmark */
48 	xfs_qcnt_t	 q_prealloc_hi_wmark;/* prealloc disabled wmark */
49 	int64_t		 q_low_space[XFS_QLOWSP_MAX];
50 	struct mutex	 q_qlock;	/* quota lock */
51 	struct completion q_flush;	/* flush completion queue */
52 	atomic_t          q_pincount;	/* dquot pin count */
53 	wait_queue_head_t q_pinwait;	/* dquot pinning wait queue */
54 } xfs_dquot_t;
55 
56 /*
57  * Lock hierarchy for q_qlock:
58  *	XFS_QLOCK_NORMAL is the implicit default,
59  * 	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
60  */
61 enum {
62 	XFS_QLOCK_NORMAL = 0,
63 	XFS_QLOCK_NESTED,
64 };
65 
66 /*
67  * Manage the q_flush completion queue embedded in the dquot.  This completion
68  * queue synchronizes processes attempting to flush the in-core dquot back to
69  * disk.
70  */
71 static inline void xfs_dqflock(xfs_dquot_t *dqp)
72 {
73 	wait_for_completion(&dqp->q_flush);
74 }
75 
76 static inline bool xfs_dqflock_nowait(xfs_dquot_t *dqp)
77 {
78 	return try_wait_for_completion(&dqp->q_flush);
79 }
80 
81 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
82 {
83 	complete(&dqp->q_flush);
84 }
85 
86 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
87 {
88 	return mutex_trylock(&dqp->q_qlock);
89 }
90 
91 static inline void xfs_dqlock(struct xfs_dquot *dqp)
92 {
93 	mutex_lock(&dqp->q_qlock);
94 }
95 
96 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
97 {
98 	mutex_unlock(&dqp->q_qlock);
99 }
100 
101 static inline int xfs_this_quota_on(struct xfs_mount *mp, int type)
102 {
103 	switch (type & XFS_DQ_ALLTYPES) {
104 	case XFS_DQ_USER:
105 		return XFS_IS_UQUOTA_ON(mp);
106 	case XFS_DQ_GROUP:
107 		return XFS_IS_GQUOTA_ON(mp);
108 	case XFS_DQ_PROJ:
109 		return XFS_IS_PQUOTA_ON(mp);
110 	default:
111 		return 0;
112 	}
113 }
114 
115 static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
116 {
117 	switch (type & XFS_DQ_ALLTYPES) {
118 	case XFS_DQ_USER:
119 		return ip->i_udquot;
120 	case XFS_DQ_GROUP:
121 		return ip->i_gdquot;
122 	case XFS_DQ_PROJ:
123 		return ip->i_pdquot;
124 	default:
125 		return NULL;
126 	}
127 }
128 
129 /*
130  * Check whether a dquot is under low free space conditions. We assume the quota
131  * is enabled and enforced.
132  */
133 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
134 {
135 	int64_t freesp;
136 
137 	freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
138 	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
139 		return true;
140 
141 	return false;
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 void		xfs_qm_dqdestroy(xfs_dquot_t *);
151 extern int		xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
152 extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
153 extern void		xfs_qm_adjust_dqtimers(xfs_mount_t *,
154 					xfs_disk_dquot_t *);
155 extern void		xfs_qm_adjust_dqlimits(struct xfs_mount *,
156 					       struct xfs_dquot *);
157 extern xfs_dqid_t	xfs_qm_id_for_quotatype(struct xfs_inode *ip,
158 					uint type);
159 extern int		xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
160 					uint type, bool can_alloc,
161 					struct xfs_dquot **dqpp);
162 extern int		xfs_qm_dqget_inode(struct xfs_inode *ip, uint type,
163 					bool can_alloc,
164 					struct xfs_dquot **dqpp);
165 extern int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
166 					uint type, struct xfs_dquot **dqpp);
167 extern int		xfs_qm_dqget_uncached(struct xfs_mount *mp,
168 					xfs_dqid_t id, uint type,
169 					struct xfs_dquot **dqpp);
170 extern void		xfs_qm_dqput(xfs_dquot_t *);
171 
172 extern void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
173 
174 extern void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
175 
176 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
177 {
178 	xfs_dqlock(dqp);
179 	dqp->q_nrefs++;
180 	xfs_dqunlock(dqp);
181 	return dqp;
182 }
183 
184 typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq, uint dqtype,
185 		void *priv);
186 int xfs_qm_dqiterate(struct xfs_mount *mp, uint dqtype,
187 		xfs_qm_dqiterate_fn iter_fn, void *priv);
188 
189 #endif /* __XFS_DQUOT_H__ */
190