1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2007 Sun Microsystems, Inc.
23 * All rights reserved. Use is subject to license terms.
24 */
25 /*
26 * Copyright 2015 Joyent, Inc.
27 */
28
29 #ifndef _SYS_FS_TMP_H
30 #define _SYS_FS_TMP_H
31
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35
36 /*
37 * tmpfs per-mount data structure.
38 *
39 * All fields are protected by tm_contents.
40 * File renames on a particular file system are protected tm_renamelck.
41 */
42 struct tmount {
43 struct vfs *tm_vfsp; /* filesystem's vfs struct */
44 struct tmpnode *tm_rootnode; /* root tmpnode */
45 char *tm_mntpath; /* name of tmpfs mount point */
46 ulong_t tm_anonmax; /* file system max anon reservation */
47 pgcnt_t tm_anonmem; /* pages of reserved anon memory */
48 dev_t tm_dev; /* unique dev # of mounted `device' */
49 uint_t tm_gen; /* pseudo generation number for files */
50 kmutex_t tm_contents; /* lock for tmount structure */
51 kmutex_t tm_renamelck; /* rename lock for this mount */
52 };
53
54 /*
55 * File system independent to tmpfs conversion macros
56 */
57 #define VFSTOTM(vfsp) ((struct tmount *)(vfsp)->vfs_data)
58 #define VTOTM(vp) ((struct tmount *)(vp)->v_vfsp->vfs_data)
59 #define VTOTN(vp) ((struct tmpnode *)(vp)->v_data)
60 #define TNTOV(tp) ((tp)->tn_vnode)
61 #define tmpnode_hold(tp) VN_HOLD(TNTOV(tp))
62 #define tmpnode_rele(tp) VN_RELE(TNTOV(tp))
63
64 /*
65 * enums
66 */
67 enum de_op { DE_CREATE, DE_MKDIR, DE_LINK, DE_RENAME }; /* direnter ops */
68 enum dr_op { DR_REMOVE, DR_RMDIR, DR_RENAME }; /* dirremove ops */
69
70 /*
71 * tmpfs_minfree is the amount (in pages) of anonymous memory that tmpfs
72 * leaves free for the rest of the system. E.g. in a system with 32MB of
73 * configured swap space, if 16MB were reserved (leaving 16MB free),
74 * tmpfs could allocate up to 16MB - tmpfs_minfree. The default value
75 * for tmpfs_minfree is btopr(TMPMINFREE) but it can cautiously patched
76 * to a different number of pages.
77 * NB: If tmpfs allocates too much swap space, other processes will be
78 * unable to execute.
79 */
80 #define TMPMINFREE 2 * 1024 * 1024 /* 2 Megabytes */
81
82 extern size_t tmpfs_minfree; /* Anonymous memory in pages */
83
84 /*
85 * tmpfs can allocate only a certain percentage of kernel memory,
86 * which is used for tmpnodes, directories, file names, etc.
87 * This is statically set as TMPMAXFRACKMEM of physical memory.
88 * The actual number of allocatable bytes can be patched in tmpfs_maxkmem.
89 */
90 #define TMPMAXFRACKMEM 25 /* 1/25 of physical memory */
91
92 extern size_t tmp_kmemspace;
93 extern size_t tmpfs_maxkmem; /* Allocatable kernel memory in bytes */
94
95 extern void tmpnode_init(struct tmount *, struct tmpnode *,
96 struct vattr *, struct cred *);
97 extern int tmpnode_trunc(struct tmount *, struct tmpnode *, ulong_t);
98 extern void tmpnode_growmap(struct tmpnode *, ulong_t);
99 extern int tdirlookup(struct tmpnode *, char *, struct tmpnode **,
100 struct cred *);
101 extern int tdirdelete(struct tmpnode *, struct tmpnode *, char *,
102 enum dr_op, struct cred *);
103 extern void tdirinit(struct tmpnode *, struct tmpnode *);
104 extern void tdirtrunc(struct tmpnode *);
105 extern void *tmp_memalloc(size_t, int);
106 extern void tmp_memfree(void *, size_t);
107 extern int tmp_resv(struct tmount *, struct tmpnode *, size_t, int);
108 extern int tmp_taccess(void *, int, struct cred *);
109 extern int tmp_sticky_remove_access(struct tmpnode *, struct tmpnode *,
110 struct cred *);
111 extern int tmp_convnum(char *, pgcnt_t *);
112 extern int tmp_convmode(char *, mode_t *);
113 extern int tdirenter(struct tmount *, struct tmpnode *, char *,
114 enum de_op, struct tmpnode *, struct tmpnode *, struct vattr *,
115 struct tmpnode **, struct cred *, caller_context_t *);
116
117 #define TMP_MUSTHAVE 0x01
118
119 #ifdef __cplusplus
120 }
121 #endif
122
123 #endif /* _SYS_FS_TMP_H */