1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #ifndef __XFS_DQUOT_H__
19 #define __XFS_DQUOT_H__
20
21 /*
22 * Dquots are structures that hold quota information about a user or a group,
23 * much like inodes are for files. In fact, dquots share many characteristics
24 * with inodes. However, dquots can also be a centralized resource, relative
25 * to a collection of inodes. In this respect, dquots share some characteristics
26 * of the superblock.
27 * XFS dquots exploit both those in its algorithms. They make every attempt
28 * to not be a bottleneck when quotas are on and have minimal impact, if any,
29 * when quotas are off.
30 */
31
32 /*
33 * The hash chain headers (hash buckets)
34 */
35 typedef struct xfs_dqhash {
36 struct xfs_dquot *qh_next;
37 mutex_t qh_lock;
38 uint qh_version; /* ever increasing version */
39 uint qh_nelems; /* number of dquots on the list */
40 } xfs_dqhash_t;
41
42 typedef struct xfs_dqlink {
43 struct xfs_dquot *ql_next; /* forward link */
44 struct xfs_dquot **ql_prevp; /* pointer to prev ql_next */
45 } xfs_dqlink_t;
46
47 struct xfs_mount;
48 struct xfs_trans;
49
50 /*
51 * This is the marker which is designed to occupy the first few
52 * bytes of the xfs_dquot_t structure. Even inside this, the freelist pointers
53 * must come first.
54 * This serves as the marker ("sentinel") when we have to restart list
55 * iterations because of locking considerations.
56 */
57 typedef struct xfs_dqmarker {
58 struct xfs_dquot*dqm_flnext; /* link to freelist: must be first */
59 struct xfs_dquot*dqm_flprev;
60 xfs_dqlink_t dqm_mplist; /* link to mount's list of dquots */
61 xfs_dqlink_t dqm_hashlist; /* link to the hash chain */
62 uint dqm_flags; /* various flags (XFS_DQ_*) */
63 } xfs_dqmarker_t;
64
65 /*
66 * The incore dquot structure
67 */
68 typedef struct xfs_dquot {
69 xfs_dqmarker_t q_lists; /* list ptrs, q_flags (marker) */
70 xfs_dqhash_t *q_hash; /* the hashchain header */
71 struct xfs_mount*q_mount; /* filesystem this relates to */
72 struct xfs_trans*q_transp; /* trans this belongs to currently */
73 uint q_nrefs; /* # active refs from inodes */
74 xfs_daddr_t q_blkno; /* blkno of dquot buffer */
75 int q_bufoffset; /* off of dq in buffer (# dquots) */
76 xfs_fileoff_t q_fileoffset; /* offset in quotas file */
77
78 struct xfs_dquot*q_gdquot; /* group dquot, hint only */
79 xfs_disk_dquot_t q_core; /* actual usage & quotas */
80 xfs_dq_logitem_t q_logitem; /* dquot log item */
81 xfs_qcnt_t q_res_bcount; /* total regular nblks used+reserved */
82 xfs_qcnt_t q_res_icount; /* total inos allocd+reserved */
83 xfs_qcnt_t q_res_rtbcount;/* total realtime blks used+reserved */
84 mutex_t q_qlock; /* quota lock */
85 struct completion q_flush; /* flush completion queue */
86 atomic_t q_pincount; /* dquot pin count */
87 wait_queue_head_t q_pinwait; /* dquot pinning wait queue */
88 #ifdef XFS_DQUOT_TRACE
89 struct ktrace *q_trace; /* trace header structure */
90 #endif
91 } xfs_dquot_t;
92
93
94 #define dq_flnext q_lists.dqm_flnext
95 #define dq_flprev q_lists.dqm_flprev
96 #define dq_mplist q_lists.dqm_mplist
97 #define dq_hashlist q_lists.dqm_hashlist
98 #define dq_flags q_lists.dqm_flags
99
100 /*
101 * Lock hierachy for q_qlock:
102 * XFS_QLOCK_NORMAL is the implicit default,
103 * XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
104 */
105 enum {
106 XFS_QLOCK_NORMAL = 0,
107 XFS_QLOCK_NESTED,
108 };
109
110 #define XFS_DQHOLD(dqp) ((dqp)->q_nrefs++)
111
112 #ifdef DEBUG
113 static inline int
XFS_DQ_IS_LOCKED(xfs_dquot_t * dqp)114 XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp)
115 {
116 if (mutex_trylock(&dqp->q_qlock)) {
117 mutex_unlock(&dqp->q_qlock);
118 return 0;
119 }
120 return 1;
121 }
122 #endif
123
124
125 /*
126 * Manage the q_flush completion queue embedded in the dquot. This completion
127 * queue synchronizes processes attempting to flush the in-core dquot back to
128 * disk.
129 */
xfs_dqflock(xfs_dquot_t * dqp)130 static inline void xfs_dqflock(xfs_dquot_t *dqp)
131 {
132 wait_for_completion(&dqp->q_flush);
133 }
134
xfs_dqflock_nowait(xfs_dquot_t * dqp)135 static inline int xfs_dqflock_nowait(xfs_dquot_t *dqp)
136 {
137 return try_wait_for_completion(&dqp->q_flush);
138 }
139
xfs_dqfunlock(xfs_dquot_t * dqp)140 static inline void xfs_dqfunlock(xfs_dquot_t *dqp)
141 {
142 complete(&dqp->q_flush);
143 }
144
145 #define XFS_DQ_IS_ON_FREELIST(dqp) ((dqp)->dq_flnext != (dqp))
146 #define XFS_DQ_IS_DIRTY(dqp) ((dqp)->dq_flags & XFS_DQ_DIRTY)
147 #define XFS_QM_ISUDQ(dqp) ((dqp)->dq_flags & XFS_DQ_USER)
148 #define XFS_QM_ISPDQ(dqp) ((dqp)->dq_flags & XFS_DQ_PROJ)
149 #define XFS_QM_ISGDQ(dqp) ((dqp)->dq_flags & XFS_DQ_GROUP)
150 #define XFS_DQ_TO_QINF(dqp) ((dqp)->q_mount->m_quotainfo)
151 #define XFS_DQ_TO_QIP(dqp) (XFS_QM_ISUDQ(dqp) ? \
152 XFS_DQ_TO_QINF(dqp)->qi_uquotaip : \
153 XFS_DQ_TO_QINF(dqp)->qi_gquotaip)
154
155 #define XFS_IS_THIS_QUOTA_OFF(d) (! (XFS_QM_ISUDQ(d) ? \
156 (XFS_IS_UQUOTA_ON((d)->q_mount)) : \
157 (XFS_IS_OQUOTA_ON((d)->q_mount))))
158
159 #ifdef XFS_DQUOT_TRACE
160 /*
161 * Dquot Tracing stuff.
162 */
163 #define DQUOT_TRACE_SIZE 64
164 #define DQUOT_KTRACE_ENTRY 1
165
166 extern void __xfs_dqtrace_entry(xfs_dquot_t *dqp, char *func,
167 void *, xfs_inode_t *);
168 #define xfs_dqtrace_entry_ino(a,b,ip) \
169 __xfs_dqtrace_entry((a), (b), (void*)__return_address, (ip))
170 #define xfs_dqtrace_entry(a,b) \
171 __xfs_dqtrace_entry((a), (b), (void*)__return_address, NULL)
172 #else
173 #define xfs_dqtrace_entry(a,b)
174 #define xfs_dqtrace_entry_ino(a,b,ip)
175 #endif
176
177 #ifdef QUOTADEBUG
178 extern void xfs_qm_dqprint(xfs_dquot_t *);
179 #else
180 #define xfs_qm_dqprint(a)
181 #endif
182
183 extern void xfs_qm_dqdestroy(xfs_dquot_t *);
184 extern int xfs_qm_dqflush(xfs_dquot_t *, uint);
185 extern int xfs_qm_dqpurge(xfs_dquot_t *);
186 extern void xfs_qm_dqunpin_wait(xfs_dquot_t *);
187 extern int xfs_qm_dqlock_nowait(xfs_dquot_t *);
188 extern void xfs_qm_dqflock_pushbuf_wait(xfs_dquot_t *dqp);
189 extern void xfs_qm_adjust_dqtimers(xfs_mount_t *,
190 xfs_disk_dquot_t *);
191 extern void xfs_qm_adjust_dqlimits(xfs_mount_t *,
192 xfs_disk_dquot_t *);
193 extern int xfs_qm_dqget(xfs_mount_t *, xfs_inode_t *,
194 xfs_dqid_t, uint, uint, xfs_dquot_t **);
195 extern void xfs_qm_dqput(xfs_dquot_t *);
196 extern void xfs_qm_dqrele(xfs_dquot_t *);
197 extern void xfs_dqlock(xfs_dquot_t *);
198 extern void xfs_dqlock2(xfs_dquot_t *, xfs_dquot_t *);
199 extern void xfs_dqunlock(xfs_dquot_t *);
200 extern void xfs_dqunlock_nonotify(xfs_dquot_t *);
201
202 #endif /* __XFS_DQUOT_H__ */
203