xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zfs_vfsops.h (revision 68afbec1fabe0d352bb5ab4ed82c44b58ec651fb)
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.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_SYS_FS_ZFS_VFSOPS_H
27 #define	_SYS_FS_ZFS_VFSOPS_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/isa_defs.h>
32 #include <sys/types32.h>
33 #include <sys/list.h>
34 #include <sys/vfs.h>
35 #include <sys/zil.h>
36 
37 #ifdef	__cplusplus
38 extern "C" {
39 #endif
40 
41 typedef struct zfsvfs zfsvfs_t;
42 
43 struct zfsvfs {
44 	vfs_t		*z_vfs;		/* generic fs struct */
45 	zfsvfs_t	*z_parent;	/* parent fs */
46 	objset_t	*z_os;		/* objset reference */
47 	uint64_t	z_root;		/* id of root znode */
48 	uint64_t	z_unlinkedobj;	/* id of unlinked zapobj */
49 	uint64_t	z_max_blksz;	/* maximum block size for files */
50 	uint64_t	z_assign;	/* TXG_NOWAIT or set by zil_replay() */
51 	zilog_t		*z_log;		/* intent log pointer */
52 	uint_t		z_acl_mode;	/* acl chmod/mode behavior */
53 	uint_t		z_acl_inherit;	/* acl inheritance behavior */
54 	boolean_t	z_atime;	/* enable atimes mount option */
55 	boolean_t	z_unmounted;	/* unmounted */
56 	krwlock_t	z_unmount_lock;
57 	krwlock_t	z_unmount_inactive_lock;
58 	list_t		z_all_znodes;	/* all vnodes in the fs */
59 	kmutex_t	z_znodes_lock;	/* lock for z_all_znodes */
60 	vnode_t		*z_ctldir;	/* .zfs directory pointer */
61 	boolean_t	z_show_ctldir;	/* expose .zfs in the root dir */
62 	boolean_t	z_issnap;	/* true if this is a snapshot */
63 	uint64_t	z_version;
64 #define	ZFS_OBJ_MTX_SZ	64
65 	kmutex_t	z_hold_mtx[ZFS_OBJ_MTX_SZ];	/* znode hold locks */
66 };
67 
68 /*
69  * Normal filesystems (those not under .zfs/snapshot) have a total
70  * file ID size limited to 12 bytes (including the length field) due to
71  * NFSv2 protocol's limitation of 32 bytes for a filehandle.  For historical
72  * reasons, this same limit is being imposed by the Solaris NFSv3 implementation
73  * (although the NFSv3 protocol actually permits a maximum of 64 bytes).  It
74  * is not possible to expand beyond 12 bytes without abandoning support
75  * of NFSv2.
76  *
77  * For normal filesystems, we partition up the available space as follows:
78  *	2 bytes		fid length (required)
79  *	6 bytes		object number (48 bits)
80  *	4 bytes		generation number (32 bits)
81  *
82  * We reserve only 48 bits for the object number, as this is the limit
83  * currently defined and imposed by the DMU.
84  */
85 typedef struct zfid_short {
86 	uint16_t	zf_len;
87 	uint8_t		zf_object[6];		/* obj[i] = obj >> (8 * i) */
88 	uint8_t		zf_gen[4];		/* gen[i] = gen >> (8 * i) */
89 } zfid_short_t;
90 
91 /*
92  * Filesystems under .zfs/snapshot have a total file ID size of 22 bytes
93  * (including the length field).  This makes files under .zfs/snapshot
94  * accessible by NFSv3 and NFSv4, but not NFSv2.
95  *
96  * For files under .zfs/snapshot, we partition up the available space
97  * as follows:
98  *	2 bytes		fid length (required)
99  *	6 bytes		object number (48 bits)
100  *	4 bytes		generation number (32 bits)
101  *	6 bytes		objset id (48 bits)
102  *	4 bytes		currently just zero (32 bits)
103  *
104  * We reserve only 48 bits for the object number and objset id, as these are
105  * the limits currently defined and imposed by the DMU.
106  */
107 typedef struct zfid_long {
108 	zfid_short_t	z_fid;
109 	uint8_t		zf_setid[6];		/* obj[i] = obj >> (8 * i) */
110 	uint8_t		zf_setgen[4];		/* gen[i] = gen >> (8 * i) */
111 } zfid_long_t;
112 
113 #define	SHORT_FID_LEN	(sizeof (zfid_short_t) - sizeof (uint16_t))
114 #define	LONG_FID_LEN	(sizeof (zfid_long_t) - sizeof (uint16_t))
115 
116 extern uint_t zfs_fsyncer_key;
117 
118 #ifdef	__cplusplus
119 }
120 #endif
121 
122 #endif	/* _SYS_FS_ZFS_VFSOPS_H */
123