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
20struct xfs_mount;
21struct xfs_trans;
22
23enum {
24 XFS_QLOWSP_1_PCNT = 0,
25 XFS_QLOWSP_3_PCNT,
26 XFS_QLOWSP_5_PCNT,
27 XFS_QLOWSP_MAX
28};
29
30struct 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
49static inline bool
50xfs_dquot_res_over_limits(
51 const struct xfs_dquot_res *qres)
52{
53 if ((qres->softlimit && qres->softlimit < qres->reserved) ||
54 (qres->hardlimit && qres->hardlimit < qres->reserved))
55 return true;
56 return false;
57}
58
59/*
60 * The incore dquot structure
61 */
62struct xfs_dquot {
63 struct list_head q_lru;
64 struct xfs_mount *q_mount;
65 xfs_dqtype_t q_type;
66 uint16_t q_flags;
67 xfs_dqid_t q_id;
68 uint q_nrefs;
69 int q_bufoffset;
70 xfs_daddr_t q_blkno;
71 xfs_fileoff_t q_fileoffset;
72
73 struct xfs_dquot_res q_blk; /* regular blocks */
74 struct xfs_dquot_res q_ino; /* inodes */
75 struct xfs_dquot_res q_rtb; /* realtime blocks */
76
77 struct xfs_dq_logitem q_logitem;
78
79 xfs_qcnt_t q_prealloc_lo_wmark;
80 xfs_qcnt_t q_prealloc_hi_wmark;
81 int64_t q_low_space[XFS_QLOWSP_MAX];
82 struct mutex q_qlock;
83 struct completion q_flush;
84 atomic_t q_pincount;
85 struct wait_queue_head q_pinwait;
86};
87
88/*
89 * Lock hierarchy for q_qlock:
90 * XFS_QLOCK_NORMAL is the implicit default,
91 * XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
92 */
93enum {
94 XFS_QLOCK_NORMAL = 0,
95 XFS_QLOCK_NESTED,
96};
97
98/*
99 * Manage the q_flush completion queue embedded in the dquot. This completion
100 * queue synchronizes processes attempting to flush the in-core dquot back to
101 * disk.
102 */
103static inline void xfs_dqflock(struct xfs_dquot *dqp)
104{
105 wait_for_completion(&dqp->q_flush);
106}
107
108static inline bool xfs_dqflock_nowait(struct xfs_dquot *dqp)
109{
110 return try_wait_for_completion(x: &dqp->q_flush);
111}
112
113static inline void xfs_dqfunlock(struct xfs_dquot *dqp)
114{
115 complete(&dqp->q_flush);
116}
117
118static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
119{
120 return mutex_trylock(lock: &dqp->q_qlock);
121}
122
123static inline void xfs_dqlock(struct xfs_dquot *dqp)
124{
125 mutex_lock(&dqp->q_qlock);
126}
127
128static inline void xfs_dqunlock(struct xfs_dquot *dqp)
129{
130 mutex_unlock(lock: &dqp->q_qlock);
131}
132
133static inline int
134xfs_dquot_type(const struct xfs_dquot *dqp)
135{
136 return dqp->q_type & XFS_DQTYPE_REC_MASK;
137}
138
139static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)
140{
141 switch (type) {
142 case XFS_DQTYPE_USER:
143 return XFS_IS_UQUOTA_ON(mp);
144 case XFS_DQTYPE_GROUP:
145 return XFS_IS_GQUOTA_ON(mp);
146 case XFS_DQTYPE_PROJ:
147 return XFS_IS_PQUOTA_ON(mp);
148 default:
149 return 0;
150 }
151}
152
153static inline struct xfs_dquot *xfs_inode_dquot(
154 struct xfs_inode *ip,
155 xfs_dqtype_t type)
156{
157 switch (type) {
158 case XFS_DQTYPE_USER:
159 return ip->i_udquot;
160 case XFS_DQTYPE_GROUP:
161 return ip->i_gdquot;
162 case XFS_DQTYPE_PROJ:
163 return ip->i_pdquot;
164 default:
165 return NULL;
166 }
167}
168
169/* Decide if the dquot's limits are actually being enforced. */
170static inline bool
171xfs_dquot_is_enforced(
172 const struct xfs_dquot *dqp)
173{
174 switch (xfs_dquot_type(dqp)) {
175 case XFS_DQTYPE_USER:
176 return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
177 case XFS_DQTYPE_GROUP:
178 return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
179 case XFS_DQTYPE_PROJ:
180 return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
181 }
182 ASSERT(0);
183 return false;
184}
185
186/*
187 * Check whether a dquot is under low free space conditions. We assume the quota
188 * is enabled and enforced.
189 */
190static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
191{
192 int64_t freesp;
193
194 freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
195 if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
196 return true;
197
198 return false;
199}
200
201void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);
202
203#define XFS_DQ_IS_LOCKED(dqp) (mutex_is_locked(&((dqp)->q_qlock)))
204#define XFS_DQ_IS_DIRTY(dqp) ((dqp)->q_flags & XFS_DQFLAG_DIRTY)
205
206void xfs_qm_dqdestroy(struct xfs_dquot *dqp);
207int xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf **bpp);
208void xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);
209void xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
210void xfs_qm_adjust_dqlimits(struct xfs_dquot *d);
211xfs_dqid_t xfs_qm_id_for_quotatype(struct xfs_inode *ip,
212 xfs_dqtype_t type);
213int xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
214 xfs_dqtype_t type, bool can_alloc,
215 struct xfs_dquot **dqpp);
216int xfs_qm_dqget_inode(struct xfs_inode *ip, xfs_dqtype_t type,
217 bool can_alloc, struct xfs_dquot **dqpp);
218int xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
219 xfs_dqtype_t type, struct xfs_dquot **dqpp);
220int xfs_qm_dqget_uncached(struct xfs_mount *mp,
221 xfs_dqid_t id, xfs_dqtype_t type,
222 struct xfs_dquot **dqpp);
223void xfs_qm_dqput(struct xfs_dquot *dqp);
224
225void xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
226
227void xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
228
229static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
230{
231 xfs_dqlock(dqp);
232 dqp->q_nrefs++;
233 xfs_dqunlock(dqp);
234 return dqp;
235}
236
237time64_t xfs_dquot_set_timeout(struct xfs_mount *mp, time64_t timeout);
238time64_t xfs_dquot_set_grace_period(time64_t grace);
239
240void xfs_qm_init_dquot_blk(struct xfs_trans *tp, xfs_dqid_t id, xfs_dqtype_t
241 type, struct xfs_buf *bp);
242
243#endif /* __XFS_DQUOT_H__ */
244

source code of linux/fs/xfs/xfs_dquot.h