xref: /openbmc/linux/fs/xfs/xfs_dquot.h (revision ce746d43)
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 struct xfs_dquot_res {
31 	/* Total resources allocated and reserved. */
32 	xfs_qcnt_t		reserved;
33 
34 	/* Total resources allocated. */
35 	xfs_qcnt_t		count;
36 
37 	/* Absolute and preferred limits. */
38 	xfs_qcnt_t		hardlimit;
39 	xfs_qcnt_t		softlimit;
40 
41 	/*
42 	 * For root dquots, this is the default grace period, in seconds.
43 	 * Otherwise, this is when the quota grace period expires,
44 	 * in seconds since the Unix epoch.
45 	 */
46 	time64_t		timer;
47 
48 	/*
49 	 * For root dquots, this is the maximum number of warnings that will
50 	 * be issued for this quota type.  Otherwise, this is the number of
51 	 * warnings issued against this quota.  Note that none of this is
52 	 * implemented.
53 	 */
54 	xfs_qwarncnt_t		warnings;
55 };
56 
57 /*
58  * The incore dquot structure
59  */
60 struct xfs_dquot {
61 	struct list_head	q_lru;
62 	struct xfs_mount	*q_mount;
63 	xfs_dqtype_t		q_type;
64 	uint16_t		q_flags;
65 	xfs_dqid_t		q_id;
66 	uint			q_nrefs;
67 	int			q_bufoffset;
68 	xfs_daddr_t		q_blkno;
69 	xfs_fileoff_t		q_fileoffset;
70 
71 	struct xfs_dquot_res	q_blk;	/* regular blocks */
72 	struct xfs_dquot_res	q_ino;	/* inodes */
73 	struct xfs_dquot_res	q_rtb;	/* realtime blocks */
74 
75 	struct xfs_dq_logitem	q_logitem;
76 
77 	xfs_qcnt_t		q_prealloc_lo_wmark;
78 	xfs_qcnt_t		q_prealloc_hi_wmark;
79 	int64_t			q_low_space[XFS_QLOWSP_MAX];
80 	struct mutex		q_qlock;
81 	struct completion	q_flush;
82 	atomic_t		q_pincount;
83 	struct wait_queue_head	q_pinwait;
84 };
85 
86 /*
87  * Lock hierarchy for q_qlock:
88  *	XFS_QLOCK_NORMAL is the implicit default,
89  *	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
90  */
91 enum {
92 	XFS_QLOCK_NORMAL = 0,
93 	XFS_QLOCK_NESTED,
94 };
95 
96 /*
97  * Manage the q_flush completion queue embedded in the dquot. This completion
98  * queue synchronizes processes attempting to flush the in-core dquot back to
99  * disk.
100  */
101 static inline void xfs_dqflock(struct xfs_dquot *dqp)
102 {
103 	wait_for_completion(&dqp->q_flush);
104 }
105 
106 static inline bool xfs_dqflock_nowait(struct xfs_dquot *dqp)
107 {
108 	return try_wait_for_completion(&dqp->q_flush);
109 }
110 
111 static inline void xfs_dqfunlock(struct xfs_dquot *dqp)
112 {
113 	complete(&dqp->q_flush);
114 }
115 
116 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
117 {
118 	return mutex_trylock(&dqp->q_qlock);
119 }
120 
121 static inline void xfs_dqlock(struct xfs_dquot *dqp)
122 {
123 	mutex_lock(&dqp->q_qlock);
124 }
125 
126 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
127 {
128 	mutex_unlock(&dqp->q_qlock);
129 }
130 
131 static inline int
132 xfs_dquot_type(const struct xfs_dquot *dqp)
133 {
134 	return dqp->q_type & XFS_DQTYPE_REC_MASK;
135 }
136 
137 static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)
138 {
139 	switch (type) {
140 	case XFS_DQTYPE_USER:
141 		return XFS_IS_UQUOTA_ON(mp);
142 	case XFS_DQTYPE_GROUP:
143 		return XFS_IS_GQUOTA_ON(mp);
144 	case XFS_DQTYPE_PROJ:
145 		return XFS_IS_PQUOTA_ON(mp);
146 	default:
147 		return 0;
148 	}
149 }
150 
151 static inline struct xfs_dquot *xfs_inode_dquot(
152 	struct xfs_inode	*ip,
153 	xfs_dqtype_t		type)
154 {
155 	switch (type) {
156 	case XFS_DQTYPE_USER:
157 		return ip->i_udquot;
158 	case XFS_DQTYPE_GROUP:
159 		return ip->i_gdquot;
160 	case XFS_DQTYPE_PROJ:
161 		return ip->i_pdquot;
162 	default:
163 		return NULL;
164 	}
165 }
166 
167 /* Decide if the dquot's limits are actually being enforced. */
168 static inline bool
169 xfs_dquot_is_enforced(
170 	const struct xfs_dquot	*dqp)
171 {
172 	switch (xfs_dquot_type(dqp)) {
173 	case XFS_DQTYPE_USER:
174 		return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
175 	case XFS_DQTYPE_GROUP:
176 		return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
177 	case XFS_DQTYPE_PROJ:
178 		return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
179 	}
180 	ASSERT(0);
181 	return false;
182 }
183 
184 /*
185  * Check whether a dquot is under low free space conditions. We assume the quota
186  * is enabled and enforced.
187  */
188 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
189 {
190 	int64_t freesp;
191 
192 	freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
193 	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
194 		return true;
195 
196 	return false;
197 }
198 
199 void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);
200 
201 #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
202 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->q_flags & XFS_DQFLAG_DIRTY)
203 
204 void		xfs_qm_dqdestroy(struct xfs_dquot *dqp);
205 int		xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf **bpp);
206 void		xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);
207 void		xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
208 void		xfs_qm_adjust_dqlimits(struct xfs_dquot *d);
209 xfs_dqid_t	xfs_qm_id_for_quotatype(struct xfs_inode *ip,
210 				xfs_dqtype_t type);
211 int		xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
212 				xfs_dqtype_t type, bool can_alloc,
213 				struct xfs_dquot **dqpp);
214 int		xfs_qm_dqget_inode(struct xfs_inode *ip, xfs_dqtype_t type,
215 				bool can_alloc, struct xfs_dquot **dqpp);
216 int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
217 				xfs_dqtype_t type, struct xfs_dquot **dqpp);
218 int		xfs_qm_dqget_uncached(struct xfs_mount *mp,
219 				xfs_dqid_t id, xfs_dqtype_t type,
220 				struct xfs_dquot **dqpp);
221 void		xfs_qm_dqput(struct xfs_dquot *dqp);
222 
223 void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
224 
225 void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
226 
227 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
228 {
229 	xfs_dqlock(dqp);
230 	dqp->q_nrefs++;
231 	xfs_dqunlock(dqp);
232 	return dqp;
233 }
234 
235 typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq,
236 		xfs_dqtype_t type, void *priv);
237 int xfs_qm_dqiterate(struct xfs_mount *mp, xfs_dqtype_t type,
238 		xfs_qm_dqiterate_fn iter_fn, void *priv);
239 
240 #endif /* __XFS_DQUOT_H__ */
241