xref: /linux/fs/xfs/xfs_dquot.h (revision 3ed1c68307c4ce53256e15b8a8830b12bdba1ff5)
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 	struct lockref		q_lockref;
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
125 xfs_dquot_type(const struct xfs_dquot *dqp)
126 {
127 	return dqp->q_type & XFS_DQTYPE_REC_MASK;
128 }
129 
130 static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)
131 {
132 	switch (type) {
133 	case XFS_DQTYPE_USER:
134 		return XFS_IS_UQUOTA_ON(mp);
135 	case XFS_DQTYPE_GROUP:
136 		return XFS_IS_GQUOTA_ON(mp);
137 	case XFS_DQTYPE_PROJ:
138 		return XFS_IS_PQUOTA_ON(mp);
139 	default:
140 		return 0;
141 	}
142 }
143 
144 static inline struct xfs_dquot *xfs_inode_dquot(
145 	struct xfs_inode	*ip,
146 	xfs_dqtype_t		type)
147 {
148 	if (xfs_is_metadir_inode(ip))
149 		return NULL;
150 
151 	switch (type) {
152 	case XFS_DQTYPE_USER:
153 		return ip->i_udquot;
154 	case XFS_DQTYPE_GROUP:
155 		return ip->i_gdquot;
156 	case XFS_DQTYPE_PROJ:
157 		return ip->i_pdquot;
158 	default:
159 		return NULL;
160 	}
161 }
162 
163 /* Decide if the dquot's limits are actually being enforced. */
164 static inline bool
165 xfs_dquot_is_enforced(
166 	const struct xfs_dquot	*dqp)
167 {
168 	switch (xfs_dquot_type(dqp)) {
169 	case XFS_DQTYPE_USER:
170 		return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
171 	case XFS_DQTYPE_GROUP:
172 		return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
173 	case XFS_DQTYPE_PROJ:
174 		return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
175 	}
176 	ASSERT(0);
177 	return false;
178 }
179 
180 /*
181  * Check whether a dquot is under low free space conditions. We assume the quota
182  * is enabled and enforced.
183  */
184 static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
185 {
186 	int64_t freesp;
187 
188 	freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;
189 	if (freesp < dqp->q_blk_prealloc.q_low_space[XFS_QLOWSP_1_PCNT])
190 		return true;
191 
192 	freesp = dqp->q_rtb.hardlimit - dqp->q_rtb.reserved;
193 	if (freesp < dqp->q_rtb_prealloc.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 *bp);
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 
222 void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
223 void		xfs_dqlockn(struct xfs_dqtrx *q);
224 
225 void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);
226 
227 int xfs_dquot_attach_buf(struct xfs_trans *tp, struct xfs_dquot *dqp);
228 int xfs_dquot_use_attached_buf(struct xfs_dquot *dqp, struct xfs_buf **bpp);
229 void xfs_dquot_detach_buf(struct xfs_dquot *dqp);
230 
231 static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
232 {
233 	lockref_get(&dqp->q_lockref);
234 	return dqp;
235 }
236 
237 time64_t xfs_dquot_set_timeout(struct xfs_mount *mp, time64_t timeout);
238 time64_t xfs_dquot_set_grace_period(time64_t grace);
239 
240 void 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