xref: /linux/fs/xfs/xfs_dquot.h (revision 3f6bc9e3ab9b127171d39f9ac6eca1abb693b731)
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 static inline bool
50 xfs_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 struct xfs_dquot_pre {
60 	xfs_qcnt_t		q_prealloc_lo_wmark;
61 	xfs_qcnt_t		q_prealloc_hi_wmark;
62 	int64_t			q_low_space[XFS_QLOWSP_MAX];
63 };
64 
65 /*
66  * The incore dquot structure
67  */
68 struct xfs_dquot {
69 	struct list_head	q_lru;
70 	struct xfs_mount	*q_mount;
71 	xfs_dqtype_t		q_type;
72 	uint16_t		q_flags;
73 	xfs_dqid_t		q_id;
74 	uint			q_nrefs;
75 	int			q_bufoffset;
76 	xfs_daddr_t		q_blkno;
77 	xfs_fileoff_t		q_fileoffset;
78 
79 	struct xfs_dquot_res	q_blk;	/* regular blocks */
80 	struct xfs_dquot_res	q_ino;	/* inodes */
81 	struct xfs_dquot_res	q_rtb;	/* realtime blocks */
82 
83 	struct xfs_dq_logitem	q_logitem;
84 
85 	struct xfs_dquot_pre	q_blk_prealloc;
86 	struct xfs_dquot_pre	q_rtb_prealloc;
87 
88 	struct mutex		q_qlock;
89 	struct completion	q_flush;
90 	atomic_t		q_pincount;
91 	struct wait_queue_head	q_pinwait;
92 };
93 
94 /*
95  * Lock hierarchy for q_qlock:
96  *	XFS_QLOCK_NORMAL is the implicit default,
97  *	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
98  */
99 enum {
100 	XFS_QLOCK_NORMAL = 0,
101 	XFS_QLOCK_NESTED,
102 };
103 
104 /*
105  * Manage the q_flush completion queue embedded in the dquot. This completion
106  * queue synchronizes processes attempting to flush the in-core dquot back to
107  * disk.
108  */
109 static inline void xfs_dqflock(struct xfs_dquot *dqp)
110 {
111 	wait_for_completion(&dqp->q_flush);
112 }
113 
114 static inline bool xfs_dqflock_nowait(struct xfs_dquot *dqp)
115 {
116 	return try_wait_for_completion(&dqp->q_flush);
117 }
118 
119 static inline void xfs_dqfunlock(struct xfs_dquot *dqp)
120 {
121 	complete(&dqp->q_flush);
122 }
123 
124 static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
125 {
126 	return mutex_trylock(&dqp->q_qlock);
127 }
128 
129 static inline void xfs_dqlock(struct xfs_dquot *dqp)
130 {
131 	mutex_lock(&dqp->q_qlock);
132 }
133 
134 static inline void xfs_dqunlock(struct xfs_dquot *dqp)
135 {
136 	mutex_unlock(&dqp->q_qlock);
137 }
138 
139 static inline int
140 xfs_dquot_type(const struct xfs_dquot *dqp)
141 {
142 	return dqp->q_type & XFS_DQTYPE_REC_MASK;
143 }
144 
145 static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)
146 {
147 	switch (type) {
148 	case XFS_DQTYPE_USER:
149 		return XFS_IS_UQUOTA_ON(mp);
150 	case XFS_DQTYPE_GROUP:
151 		return XFS_IS_GQUOTA_ON(mp);
152 	case XFS_DQTYPE_PROJ:
153 		return XFS_IS_PQUOTA_ON(mp);
154 	default:
155 		return 0;
156 	}
157 }
158 
159 static inline struct xfs_dquot *xfs_inode_dquot(
160 	struct xfs_inode	*ip,
161 	xfs_dqtype_t		type)
162 {
163 	switch (type) {
164 	case XFS_DQTYPE_USER:
165 		return ip->i_udquot;
166 	case XFS_DQTYPE_GROUP:
167 		return ip->i_gdquot;
168 	case XFS_DQTYPE_PROJ:
169 		return ip->i_pdquot;
170 	default:
171 		return NULL;
172 	}
173 }
174 
175 /* Decide if the dquot's limits are actually being enforced. */
176 static inline bool
177 xfs_dquot_is_enforced(
178 	const struct xfs_dquot	*dqp)
179 {
180 	switch (xfs_dquot_type(dqp)) {
181 	case XFS_DQTYPE_USER:
182 		return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
183 	case XFS_DQTYPE_GROUP:
184 		return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
185 	case XFS_DQTYPE_PROJ:
186 		return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
187 	}
188 	ASSERT(0);
189 	return false;
190 }
191 
192 /*
193  * Check whether a dquot is under low free space conditions. We assume the quota
194  * is enabled and enforced.
195  */
196 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
197 {
198 	int64_t freesp;
199 
200 	freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
201 	if (freesp < dqp->q_blk_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
202 		return true;
203 
204 	freesp = dqp->q_rtb.hardlimit - dqp->q_rtb.reserved;
205 	if (freesp < dqp->q_rtb_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
206 		return true;
207 
208 	return false;
209 }
210 
211 void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);
212 
213 #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
214 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->q_flags & XFS_DQFLAG_DIRTY)
215 
216 void		xfs_qm_dqdestroy(struct xfs_dquot *dqp);
217 int		xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf *bp);
218 void		xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);
219 void		xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
220 void		xfs_qm_adjust_dqlimits(struct xfs_dquot *d);
221 xfs_dqid_t	xfs_qm_id_for_quotatype(struct xfs_inode *ip,
222 				xfs_dqtype_t type);
223 int		xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,
224 				xfs_dqtype_t type, bool can_alloc,
225 				struct xfs_dquot **dqpp);
226 int		xfs_qm_dqget_inode(struct xfs_inode *ip, xfs_dqtype_t type,
227 				bool can_alloc, struct xfs_dquot **dqpp);
228 int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,
229 				xfs_dqtype_t type, struct xfs_dquot **dqpp);
230 int		xfs_qm_dqget_uncached(struct xfs_mount *mp,
231 				xfs_dqid_t id, xfs_dqtype_t type,
232 				struct xfs_dquot **dqpp);
233 void		xfs_qm_dqput(struct xfs_dquot *dqp);
234 
235 void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
236 void		xfs_dqlockn(struct xfs_dqtrx *q);
237 
238 void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
239 
240 int xfs_dquot_attach_buf(struct xfs_trans *tp, struct xfs_dquot *dqp);
241 int xfs_dquot_use_attached_buf(struct xfs_dquot *dqp, struct xfs_buf **bpp);
242 void xfs_dquot_detach_buf(struct xfs_dquot *dqp);
243 
244 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
245 {
246 	xfs_dqlock(dqp);
247 	dqp->q_nrefs++;
248 	xfs_dqunlock(dqp);
249 	return dqp;
250 }
251 
252 time64_t xfs_dquot_set_timeout(struct xfs_mount *mp, time64_t timeout);
253 time64_t xfs_dquot_set_grace_period(time64_t grace);
254 
255 void xfs_qm_init_dquot_blk(struct xfs_trans *tp, xfs_dqid_t id, xfs_dqtype_t
256 		type, struct xfs_buf *bp);
257 
258 #endif /* __XFS_DQUOT_H__ */
259