bsd/sys/mount_internal.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1989, 1991, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)mount.h     8.21 (Berkeley) 5/20/95
  64  */
  65
  66 #ifndef _SYS_MOUNT_INTERNAL_H_
  67 #define _SYS_MOUNT_INTERNAL_H_
  68
  69 #include <sys/appleapiopts.h>
  70 #ifndef KERNEL
  71 #include <sys/ucred.h>
  72 #else
  73 #include <sys/kernel_types.h>
  74 #include <sys/namei.h>
  75 #endif
  76 #include <sys/queue.h>
  77 #include <sys/lock.h>
  78 #include <net/radix.h>
  79 #include <sys/socket.h>         /* XXX for AF_MAX */
  80 #include <sys/vfs_context.h>            /* XXX for AF_MAX */
  81 #include <sys/mount.h>
  82 #include <sys/cdefs.h>
  83
  84 /*
  85  * Structure per mounted file system.  Each mounted file system has an
  86  * array of operations and an instance record.  The file systems are
  87  * put on a doubly linked list.
  88  */
  89 TAILQ_HEAD(vnodelst, vnode);
  90
  91 struct mount {
  92         TAILQ_ENTRY(mount) mnt_list;            /* mount list */
  93         int32_t         mnt_count;              /* reference on the mount */
  94         lck_mtx_t       mnt_mlock;              /* mutex that protects mount point */
  95         struct vfsops   *mnt_op;                /* operations on fs */
  96         struct vfstable *mnt_vtable;            /* configuration info */
  97         struct vnode    *mnt_vnodecovered;      /* vnode we mounted on */
  98         struct vnodelst mnt_vnodelist;          /* list of vnodes this mount */
  99         struct vnodelst mnt_workerqueue;                /* list of vnodes this mount */
 100         struct vnodelst mnt_newvnodes;          /* list of vnodes this mount */
 101         int             mnt_flag;               /* flags */
 102         int             mnt_kern_flag;          /* kernel only flags */
 103         int             mnt_lflag;                      /* mount life cycle flags */
 104         int             mnt_maxsymlinklen;      /* max size of short symlink */
 105         struct vfsstatfs        mnt_vfsstat;            /* cache of filesystem stats */
 106         qaddr_t         mnt_data;               /* private data */
 107         /* Cached values of the IO constraints for the device */
 108         u_int32_t       mnt_maxreadcnt;         /* Max. byte count for read */
 109         u_int32_t       mnt_maxwritecnt;        /* Max. byte count for write */
 110         u_int32_t       mnt_segreadcnt;         /* Max. segment count for read */
 111         u_int32_t       mnt_segwritecnt;        /* Max. segment count for write */
 112         u_int32_t       mnt_maxsegreadsize;     /* Max. segment read size  */
 113         u_int32_t       mnt_maxsegwritesize;    /* Max. segment write size */
 114         u_int32_t       mnt_devblocksize;       /* the underlying device block size */
 115         lck_rw_t        mnt_rwlock;             /* mutex readwrite lock */
 116         lck_mtx_t       mnt_renamelock;         /* mutex that serializes renames that change shape of tree */
 117         vnode_t         mnt_devvp;              /* the device mounted on for local file systems */
 118         int32_t         mnt_crossref;           /* refernces to cover lookups  crossing into mp */
 119         int32_t         mnt_iterref;            /* refernces to cover iterations; drained makes it -ve  */
 120
 121         /* XXX 3762912 hack to support HFS filesystem 'owner' */
 122         uid_t           mnt_fsowner;
 123         gid_t           mnt_fsgroup;
 124 };
 125
 126 /* XXX 3762912 hack to support HFS filesystem 'owner' */
 127 #define vfs_setowner(_mp, _uid, _gid)   do {(_mp)->mnt_fsowner = (_uid); (_mp)->mnt_fsgroup = (_gid); } while (0)
 128
 129
 130 /* mount point to which dead vps point to */
 131 extern struct mount * dead_mountp;
 132
 133 /*
 134  * Internal filesystem control flags stored in mnt_kern_flag.
 135  *
 136  * MNTK_UNMOUNT locks the mount entry so that name lookup cannot proceed
 137  * past the mount point.  This keeps the subtree stable during mounts
 138  * and unmounts.
 139  *
 140  * Note:        We are counting down on new bit assignments.  This is
 141  *              because the bits here were broken out from the high bits
 142  *              of the mount flags.
 143  */
 144 #define MNTK_LOCK_LOCAL         0x00100000      /* advisory locking is done above the VFS itself */
 145 #define MNTK_VIRTUALDEV         0x00200000      /* mounted on a virtual device i.e. a disk image */
 146 #define MNTK_ROOTDEV            0x00400000      /* this filesystem resides on the same device as the root */
 147 #define MNTK_UNMOUNT            0x01000000      /* unmount in progress */
 148 #define MNTK_MWAIT              0x02000000      /* waiting for unmount to finish */
 149 #define MNTK_WANTRDWR           0x04000000      /* upgrade to read/write requested */
 150 #if REV_ENDIAN_FS
 151 #define MNT_REVEND              0x08000000      /* Reverse endian FS */
 152 #endif /* REV_ENDIAN_FS */
 153 #define MNTK_FRCUNMOUNT         0x10000000      /* Forced unmount wanted. */
 154 #define MNTK_AUTH_OPAQUE        0x20000000      /* authorisation decisions are not made locally */
 155 #define MNTK_AUTH_OPAQUE_ACCESS 0x40000000      /* VNOP_ACCESS is reliable for remote auth */
 156 #define MNTK_EXTENDED_SECURITY  0x80000000      /* extended security supported */
 157
 158 #define MNT_LBUSY               0x00000001      /* mount is busy */
 159 #define MNT_LUNMOUNT            0x00000002      /* mount in unmount */
 160 #define MNT_LFORCE              0x00000004      /* mount in forced unmount */
 161 #define MNT_LDRAIN              0x00000008      /* mount in drain */
 162 #define MNT_LITER               0x00000010      /* mount in iteration */
 163 #define MNT_LNEWVN              0x00000020      /* mount has new vnodes created */
 164 #define MNT_LWAIT               0x00000040      /* wait for unmount op */
 165 #define MNT_LITERWAIT           0x00000080      /* mount in iteration */
 166 #define MNT_LDEAD               0x00000100      /* mount already unmounted*/
 167
 168
 169 /*
 170  * Generic file handle
 171  */
 172 #define NFS_MAX_FH_SIZE         64
 173 #define NFSV2_MAX_FH_SIZE       32
 174 struct fhandle {
 175         int             fh_len;                         /* length of file handle */
 176         unsigned char   fh_data[NFS_MAX_FH_SIZE];       /* file handle value */
 177 };
 178 typedef struct fhandle  fhandle_t;
 179
 180
 181
 182 /*
 183  * Filesystem configuration information. One of these exists for each
 184  * type of filesystem supported by the kernel. These are searched at
 185  * mount time to identify the requested filesystem.
 186  */
 187 struct vfstable {
 188 /* THE FOLLOWING SHOULD KEEP THE SAME FOR user compat with sysctl */
 189         struct  vfsops *vfc_vfsops;     /* filesystem operations vector */
 190         char    vfc_name[MFSNAMELEN];   /* filesystem type name */
 191         int     vfc_typenum;            /* historic filesystem type number */
 192         int     vfc_refcount;           /* number mounted of this type */
 193         int     vfc_flags;              /* permanent flags */
 194         int     (*vfc_mountroot)(mount_t, vnode_t, vfs_context_t);      /* if != NULL, routine to mount root */
 195         struct  vfstable *vfc_next;     /* next in list */
 196 /* Till the above we SHOULD KEEP THE SAME FOR user compat with sysctl */
 197         int         vfc_threadsafe;     /* FS is thread & premeption safe */
 198         lck_mtx_t   vfc_lock;           /* for non-threaded file systems */
 199         int             vfc_vfsflags;   /* for optional types */
 200         void *          vfc_descptr;    /* desc table allocated address */
 201         int                     vfc_descsize;   /* size allocated for desc table */
 202         int             vfc_64bitready; /* The file system is ready for 64bit */
 203 };
 204
 205 #define VFC_VFSLOCALARGS        0x02
 206 #define VFC_VFSGENERICARGS      0x04
 207 #define VFC_VFSNATIVEXATTR      0x10
 208
 209
 210 extern int maxvfsconf;          /* highest defined filesystem type */
 211 extern struct vfstable  *vfsconf;       /* head of list of filesystem types */
 212 extern int maxvfsslots;         /* Maximum slots available to be used */
 213 extern int numused_vfsslots;    /* number of slots already used */
 214
 215 /* the following two are xnu private */
 216 struct vfstable *       vfstable_add(struct     vfstable *);
 217 int     vfstable_del(struct vfstable *);
 218
 219
 220 struct vfsmount_args {
 221         union {
 222                 struct {
 223                         char * mnt_fspec;
 224                         void * mnt_fsdata;
 225                 } mnt_localfs_args;
 226                 struct {
 227                         void *  mnt_fsdata;             /* FS specific */
 228                 } mnt_remotefs_args;
 229         } mountfs_args;
 230 };
 231
 232
 233 /*
 234  * LP64 version of statfs structure.
 235  * NOTE - must be kept in sync with struct statfs in mount.h
 236  */
 237 #if __DARWIN_ALIGN_NATURAL
 238 #pragma options align=natural
 239 #endif
 240
 241 struct user_statfs {
 242         short           f_otype;                /* TEMPORARY SHADOW COPY OF f_type */
 243         short           f_oflags;               /* TEMPORARY SHADOW COPY OF f_flags */
 244         user_long_t     f_bsize;                /* fundamental file system block size */
 245         user_long_t     f_iosize;               /* optimal transfer block size */
 246         user_long_t     f_blocks;               /* total data blocks in file system */
 247         user_long_t     f_bfree;                /* free blocks in fs */
 248         user_long_t     f_bavail;               /* free blocks avail to non-superuser */
 249         user_long_t     f_files;                /* total file nodes in file system */
 250         user_long_t     f_ffree;                /* free file nodes in fs */
 251         fsid_t          f_fsid;                 /* file system id */
 252         uid_t           f_owner;                /* user that mounted the filesystem */
 253         short           f_reserved1;    /* spare for later */
 254         short           f_type;                 /* type of filesystem */
 255     user_long_t f_flags;                /* copy of mount exported flags */
 256         user_long_t f_reserved2[2];     /* reserved for future use */
 257         char            f_fstypename[MFSNAMELEN]; /* fs type name */
 258         char            f_mntonname[MNAMELEN];  /* directory on which mounted */
 259         char            f_mntfromname[MNAMELEN];/* mounted filesystem */
 260 #if COMPAT_GETFSSTAT
 261         char            f_reserved3[0]; /* For alignment */
 262         user_long_t     f_reserved4[0]; /* For future use */
 263 #else
 264         char            f_reserved3;    /* For alignment */
 265         user_long_t     f_reserved4[4]; /* For future use */
 266 #endif
 267 };
 268
 269 #if __DARWIN_ALIGN_NATURAL
 270 #pragma options align=reset
 271 #endif
 272
 273 __BEGIN_DECLS
 274
 275 extern TAILQ_HEAD(mntlist, mount) mountlist;
 276 void mount_list_lock(void);
 277 void mount_list_unlock(void);
 278 void mount_lock_init(mount_t);
 279 void mount_lock_destroy(mount_t);
 280 void mount_lock(mount_t);
 281 void mount_unlock(mount_t);
 282 void mount_lock_renames(mount_t);
 283 void mount_unlock_renames(mount_t);
 284 void mount_ref(mount_t, int);
 285 void mount_drop(mount_t, int);
 286
 287 /* vfs_rootmountalloc should be kept as a private api */
 288 errno_t vfs_rootmountalloc(const char *, const char *, mount_t *mpp);
 289 errno_t vfs_init_io_attributes(vnode_t, mount_t);
 290
 291 int     vfs_mountroot(void);
 292 void    vfs_unmountall(void);
 293 int     safedounmount(struct mount *, int, struct proc *);
 294 int     dounmount(struct mount *, int, struct proc *);
 295
 296 /* xnuy internal api */
 297 void  mount_dropcrossref(mount_t, vnode_t, int);
 298 int validfsnode(mount_t);
 299 mount_t mount_lookupby_volfsid(int, int);
 300 mount_t mount_list_lookupby_fsid(fsid_t *, int, int);
 301 int  mount_iterref(mount_t, int);
 302 int  mount_isdrained(mount_t, int);
 303 void mount_iterdrop(mount_t);
 304 void mount_iterdrain(mount_t);
 305 void mount_iterreset(mount_t);
 306
 307 __END_DECLS
 308
 309 #endif /* !_SYS_MOUNT_INTERNAL_H_ */