usr/src/uts/common/sys/fs/lofs_info.h

   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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /*
  27  * Loopback mount info - one per mount
  28  */
  29
  30 #ifndef _SYS_FS_LOFS_INFO_H
  31 #define _SYS_FS_LOFS_INFO_H
  32
  33 #ifdef _KERNEL
  34 #include <sys/vfs_opreg.h>
  35 #endif
  36
  37 #ifdef  __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 struct lnode;
  42
  43 struct lobucket {
  44         kmutex_t        lh_lock;        /* lock protecting bucket contents */
  45         struct lnode    *lh_chain;      /* vnode chain for this bucket */
  46         uint_t          lh_count;       /* Number of vnodes in chain */
  47         /* Pad up to 64-byte boundary to avoid false sharing */
  48 #ifdef _LP64
  49         char            _pad[44];
  50 #else
  51         char            _pad[48];
  52 #endif
  53 };
  54
  55 struct lo_retired_ht {
  56         struct lo_retired_ht    *lrh_next;
  57         struct lobucket         *lrh_table;
  58         uint_t                  lrh_size;
  59 };
  60
  61 struct loinfo {
  62         struct vfs      *li_realvfs;    /* real vfs of mount */
  63         struct vfs      *li_mountvfs;   /* loopback vfs */
  64         struct vnode    *li_rootvp;     /* root vnode of this vfs */
  65         int              li_mflag;      /* mount flags to inherit */
  66         int              li_dflag;      /* mount flags to not inherit */
  67         uint_t           li_refct;      /* # outstanding vnodes */
  68         volatile uint_t  li_htsize;     /* # buckets in hashtable */
  69         struct lobucket *volatile li_hashtable; /* table of per-mount vnodes */
  70         struct lfsnode  *li_lfs;        /* list of other vfss */
  71         kmutex_t         li_lfslock;    /* lock protecting li_lfs */
  72         kmutex_t         li_htlock;     /* protect hashtable, htsize, retired */
  73         struct lo_retired_ht *li_retired; /* list of retired hashtables */
  74         int              li_flag;       /* filesystem behavior flags */
  75 };
  76
  77 /* inheritable mount flags - propagated from real vfs to loopback */
  78 #define INHERIT_VFS_FLAG        \
  79         (VFS_RDONLY|VFS_NOSETUID|VFS_NODEVICES|VFS_XATTR|VFS_NBMAND|VFS_NOEXEC)
  80
  81 /*
  82  * "nosub" is used to provide NFS server-like semantics for lo_lookup(): never
  83  * traverse mount points for sub-mounts.  The lookup will instead look under
  84  * the mount point.
  85  */
  86 #define MNTOPT_LOFS_NOSUB       "nosub"
  87 #define MNTOPT_LOFS_SUB         "sub"
  88
  89 /*
  90  * Flag values (for li_flag)
  91  */
  92 #define LO_NOSUB        0x02    /* don't traverse sub-mounts */
  93
  94 /*
  95  * lfsnodes are allocated as new real vfs's are encountered
  96  * when looking up things in a loopback name space
  97  * It contains a new vfs which is paired with the real vfs
  98  * so that vfs ops (fsstat) can get to the correct real vfs
  99  * given just a loopback vfs
 100  */
 101 struct lfsnode {
 102         struct lfsnode  *lfs_next;      /* next in loinfo list */
 103         struct vfs      *lfs_realvfs;   /* real vfs */
 104         struct vnode    *lfs_realrootvp; /* real root vp */
 105         struct vfs       lfs_vfs;       /* new loopback vfs */
 106 };
 107
 108 #define vtoli(VFSP)     ((struct loinfo *)((VFSP)->vfs_data))
 109
 110 #ifdef _KERNEL
 111 extern struct vfs *lo_realvfs(struct vfs *, struct vnode **);
 112 extern void lofs_subrinit(void);
 113 extern void lofs_subrfini(void);
 114
 115 extern void lsetup(struct loinfo *, uint_t);
 116 extern void ldestroy(struct loinfo *);
 117
 118 extern const struct fs_operation_def lo_vnodeops_template[];
 119
 120 extern struct vnodeops *lo_vnodeops;
 121 extern vfsops_t *lo_vfsops;
 122 extern struct mod_ops mod_fsops;
 123
 124 #endif /* _KERNEL */
 125
 126
 127 #ifdef  __cplusplus
 128 }
 129 #endif
 130
 131 #endif  /* _SYS_FS_LOFS_INFO_H */