[apple/xnu.git] / bsd / sys / mount_internal.h

/*
 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
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 * may not be used to create, or enable the creation or redistribution of,
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 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
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/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1989, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)mount.h     8.21 (Berkeley) 5/20/95
 */
/*
 * NOTICE: This file was modified by McAfee Research in 2004 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#ifndef _SYS_MOUNT_INTERNAL_H_
#define _SYS_MOUNT_INTERNAL_H_

#include <sys/appleapiopts.h>
#ifndef KERNEL
#include <sys/ucred.h>
#else
#include <sys/kernel_types.h>
#include <sys/namei.h>
#endif
#include <sys/queue.h>
#include <sys/lock.h>
#include <net/radix.h>
#include <sys/socket.h>         /* XXX for AF_MAX */
#include <sys/vfs_context.h>            /* XXX for AF_MAX */
#include <sys/mount.h>
#include <sys/cdefs.h>

struct label;

/*
 * Structure per mounted file system.  Each mounted file system has an
 * array of operations and an instance record.  The file systems are
 * put on a doubly linked list.
 */
TAILQ_HEAD(vnodelst, vnode);

struct mount {
        TAILQ_ENTRY(mount) mnt_list;            /* mount list */
        int32_t         mnt_count;              /* reference on the mount */
        lck_mtx_t       mnt_mlock;              /* mutex that protects mount point */
        struct vfsops   *mnt_op;                /* operations on fs */
        struct vfstable *mnt_vtable;            /* configuration info */
        struct vnode    *mnt_vnodecovered;      /* vnode we mounted on */
        struct vnodelst mnt_vnodelist;          /* list of vnodes this mount */
        struct vnodelst mnt_workerqueue;                /* list of vnodes this mount */
        struct vnodelst mnt_newvnodes;          /* list of vnodes this mount */
        int             mnt_flag;               /* flags */
        int             mnt_kern_flag;          /* kernel only flags */
        int             mnt_lflag;                      /* mount life cycle flags */
        int             mnt_maxsymlinklen;      /* max size of short symlink */
        struct vfsstatfs        mnt_vfsstat;            /* cache of filesystem stats */
        qaddr_t         mnt_data;               /* private data */
        /* Cached values of the IO constraints for the device */
        u_int32_t       mnt_maxreadcnt;         /* Max. byte count for read */
        u_int32_t       mnt_maxwritecnt;        /* Max. byte count for write */
        u_int32_t       mnt_segreadcnt;         /* Max. segment count for read */
        u_int32_t       mnt_segwritecnt;        /* Max. segment count for write */
        u_int32_t       mnt_maxsegreadsize;     /* Max. segment read size  */
        u_int32_t       mnt_maxsegwritesize;    /* Max. segment write size */
        u_int32_t       mnt_alignmentmask;      /* Mask of bits that aren't addressable via DMA */
        u_int32_t       mnt_devblocksize;       /* the underlying device block size */
        u_int32_t       mnt_ioflags;            /* flags for  underlying device */
        lck_rw_t        mnt_rwlock;             /* mutex readwrite lock */
        lck_mtx_t       mnt_renamelock;         /* mutex that serializes renames that change shape of tree */
        vnode_t         mnt_devvp;              /* the device mounted on for local file systems */
        uint32_t        mnt_devbsdunit;         /* the BSD unit number of the device */
        int32_t         mnt_crossref;           /* refernces to cover lookups  crossing into mp */
        int32_t         mnt_iterref;            /* refernces to cover iterations; drained makes it -ve  */
 
        /* XXX 3762912 hack to support HFS filesystem 'owner' */
        uid_t           mnt_fsowner;
        gid_t           mnt_fsgroup;

        struct label    *mnt_mntlabel;          /* MAC mount label */
        struct label    *mnt_fslabel;           /* MAC default fs label */

        /*
         * cache the rootvp of the last mount point
         * in the chain in the mount struct pointed
         * to by the vnode sitting in '/'
         * this cache is used to shortcircuit the
         * mount chain traversal and allows us
         * to traverse to the true underlying rootvp
         * in 1 easy step inside of 'cache_lookup_path'
         *
         * make sure to validate against the cached vid
         * in case the rootvp gets stolen away since
         * we don't take an explicit long term reference
         * on it when we mount it
         */
        vnode_t         mnt_realrootvp;
        int             mnt_realrootvp_vid;
        /*
         * bumped each time a mount or unmount
         * occurs... its used to invalidate
         * 'mnt_realrootvp' from the cache
         */
        int             mnt_generation;
        /*
         * if 'MNTK_AUTH_CACHE_TIMEOUT' is 
         * set, then 'mnt_authcache_ttl' is
         * the time-to-live for the per-vnode authentication cache
         * on this mount... if zero, no cache is maintained...
         * if 'MNTK_AUTH_CACHE_TIMEOUT' isn't set, its the
         * time-to-live for the cached lookup right for
         * volumes marked 'MNTK_AUTH_OPAQUE'.
         */
        int             mnt_authcache_ttl;
        /*
         * The proc structure pointer and process ID form a
         * sufficiently unique duple identifying the process
         * hosting this mount point. Set by vfs_markdependency()
         * and utilized in new_vnode() to avoid reclaiming vnodes
         * with this dependency (radar 5192010).
         */
        pid_t           mnt_dependent_pid;
        void            *mnt_dependent_process;
};

/*
 * default number of seconds to keep cached lookup
 * rights valid on mounts marked MNTK_AUTH_OPAQUE
 */
#define CACHED_LOOKUP_RIGHT_TTL         2

/*
 * ioflags
 */
#define MNT_IOFLAGS_FUA_SUPPORTED       0x00000001

  
/* XXX 3762912 hack to support HFS filesystem 'owner' */
#define vfs_setowner(_mp, _uid, _gid)   do {(_mp)->mnt_fsowner = (_uid); (_mp)->mnt_fsgroup = (_gid); } while (0)


/* mount point to which dead vps point to */
extern struct mount * dead_mountp;

/*
 * Internal filesystem control flags stored in mnt_kern_flag.
 *
 * MNTK_UNMOUNT locks the mount entry so that name lookup cannot proceed
 * past the mount point.  This keeps the subtree stable during mounts
 * and unmounts.
 *
 * Note:        We are counting down on new bit assignments.  This is
 *              because the bits here were broken out from the high bits
 *              of the mount flags.
 */
#define MNTK_AUTH_CACHE_TTL     0x00008000      /* rights cache has TTL - TTL of 0 disables cache */
#define MNTK_PATH_FROM_ID       0x00010000      /* mounted file system supports id-to-path lookups */
#define MNTK_UNMOUNT_PREFLIGHT  0x00020000      /* mounted file system wants preflight check during unmount */
#define MNTK_NAMED_STREAMS      0x00040000      /* mounted file system supports Named Streams VNOPs */
#define MNTK_EXTENDED_ATTRS     0x00080000      /* mounted file system supports Extended Attributes VNOPs */
#define MNTK_LOCK_LOCAL         0x00100000      /* advisory locking is done above the VFS itself */
#define MNTK_VIRTUALDEV         0x00200000      /* mounted on a virtual device i.e. a disk image */
#define MNTK_ROOTDEV            0x00400000      /* this filesystem resides on the same device as the root */
#define MNTK_UNMOUNT            0x01000000      /* unmount in progress */
#define MNTK_MWAIT              0x02000000      /* waiting for unmount to finish */
#define MNTK_WANTRDWR           0x04000000      /* upgrade to read/write requested */
#if REV_ENDIAN_FS
#define MNT_REVEND              0x08000000      /* Reverse endian FS */
#endif /* REV_ENDIAN_FS */
#define MNTK_FRCUNMOUNT         0x10000000      /* Forced unmount wanted. */
#define MNTK_AUTH_OPAQUE        0x20000000      /* authorisation decisions are not made locally */
#define MNTK_AUTH_OPAQUE_ACCESS 0x40000000      /* VNOP_ACCESS is reliable for remote auth */
#define MNTK_EXTENDED_SECURITY  0x80000000      /* extended security supported */

#define MNT_LBUSY               0x00000001      /* mount is busy */
#define MNT_LUNMOUNT            0x00000002      /* mount in unmount */
#define MNT_LFORCE              0x00000004      /* mount in forced unmount */
#define MNT_LDRAIN              0x00000008      /* mount in drain */
#define MNT_LITER               0x00000010      /* mount in iteration */
#define MNT_LNEWVN              0x00000020      /* mount has new vnodes created */
#define MNT_LWAIT               0x00000040      /* wait for unmount op */
#define MNT_LITERWAIT           0x00000080      /* mount in iteration */
#define MNT_LDEAD               0x00000100      /* mount already unmounted*/


/*
 * Generic file handle
 */
#define NFS_MAX_FH_SIZE         NFSV4_MAX_FH_SIZE
#define NFSV4_MAX_FH_SIZE       128
#define NFSV3_MAX_FH_SIZE       64
#define NFSV2_MAX_FH_SIZE       32
struct fhandle {
        int             fh_len;                         /* length of file handle */
        unsigned char   fh_data[NFS_MAX_FH_SIZE];       /* file handle value */
};
typedef struct fhandle  fhandle_t;



/*
 * Filesystem configuration information. One of these exists for each
 * type of filesystem supported by the kernel. These are searched at
 * mount time to identify the requested filesystem.
 */
struct vfstable {
/* THE FOLLOWING SHOULD KEEP THE SAME FOR user compat with sysctl */
        struct  vfsops *vfc_vfsops;     /* filesystem operations vector */
        char    vfc_name[MFSNAMELEN];   /* filesystem type name */
        int     vfc_typenum;            /* historic filesystem type number */
        int     vfc_refcount;           /* number mounted of this type */
        int     vfc_flags;              /* permanent flags */
        int     (*vfc_mountroot)(mount_t, vnode_t, vfs_context_t);      /* if != NULL, routine to mount root */
        struct  vfstable *vfc_next;     /* next in list */
/* Till the above we SHOULD KEEP THE SAME FOR user compat with sysctl */
        int         vfc_threadsafe;     /* FS is thread & premeption safe */
        lck_mtx_t   vfc_lock;           /* for non-threaded file systems */
        int             vfc_vfsflags;   /* for optional types */
        void *          vfc_descptr;    /* desc table allocated address */
        int                     vfc_descsize;   /* size allocated for desc table */
        int             vfc_64bitready; /* The file system is ready for 64bit */
};

/* vfc_vfsflags: */
#define VFC_VFSLOCALARGS        0x02
#define VFC_VFSGENERICARGS      0x04
#define VFC_VFSNATIVEXATTR      0x10
#define VFC_VFSDIRLINKS         0x20
#define VFC_VFSPREFLIGHT        0x40
#define VFC_VFSREADDIR_EXTENDED 0x80
#define VFC_VFSNOMACLABEL       0x1000

extern int maxvfsconf;          /* highest defined filesystem type */
extern struct vfstable  *vfsconf;       /* head of list of filesystem types */
extern int maxvfsslots;         /* Maximum slots available to be used */
extern int numused_vfsslots;    /* number of slots already used */

/* the following two are xnu private */
struct vfstable *       vfstable_add(struct     vfstable *);
int     vfstable_del(struct vfstable *);


struct vfsmount_args {
        union {
                struct {
                        char * mnt_fspec;
                        void * mnt_fsdata;
                } mnt_localfs_args;
                struct {
                        void *  mnt_fsdata;             /* FS specific */
                } mnt_remotefs_args;
        } mountfs_args;
};


/*
 * LP64 version of statfs structure.
 * NOTE - must be kept in sync with struct statfs in mount.h
 */
struct user_statfs {
        short           f_otype;                /* TEMPORARY SHADOW COPY OF f_type */
        short           f_oflags;               /* TEMPORARY SHADOW COPY OF f_flags */
        user_long_t     f_bsize __attribute((aligned(8)));              /* fundamental file system block size */
        user_long_t     f_iosize;               /* optimal transfer block size */
        user_long_t     f_blocks;               /* total data blocks in file system */
        user_long_t     f_bfree;                /* free blocks in fs */
        user_long_t     f_bavail;               /* free blocks avail to non-superuser */
        user_long_t     f_files;                /* total file nodes in file system */
        user_long_t     f_ffree;                /* free file nodes in fs */
        fsid_t          f_fsid;                 /* file system id */
        uid_t           f_owner;                /* user that mounted the filesystem */
        short           f_reserved1;    /* spare for later */
        short           f_type;                 /* type of filesystem */
    user_long_t f_flags;                /* copy of mount exported flags */
        user_long_t f_reserved2[2];     /* reserved for future use */
        char            f_fstypename[MFSNAMELEN]; /* fs type name */
        char            f_mntonname[MNAMELEN];  /* directory on which mounted */
        char            f_mntfromname[MNAMELEN];/* mounted filesystem */
#if COMPAT_GETFSSTAT
        char            f_reserved3[0]; /* For alignment */
        user_long_t     f_reserved4[0]; /* For future use */
#else
        char            f_reserved3;    /* For alignment */
        user_long_t     f_reserved4[4] __attribute((aligned(8)));       /* For future use */
#endif
};

/*
 * throttle I/Os are affected only by normal I/Os happening on the same bsd device node.  For example, disk1s3 and
 * disk1s5 are the same device node, while disk1s3 and disk2 are not (although disk2 might be a mounted disk image file
 * and the disk image file resides on a partition in disk1).  The following constant defines the maximum number of
 * different bsd device nodes the algorithm can consider, and larger numbers are rounded by this maximum.  Since
 * throttled I/O is usually useful in non-server environment only, a small number 16 is enough in most cases
 */
#define LOWPRI_MAX_NUM_DEV 16

__BEGIN_DECLS

extern int mount_generation;
extern TAILQ_HEAD(mntlist, mount) mountlist;
void mount_list_lock(void);
void mount_list_unlock(void);
void mount_lock_init(mount_t);
void mount_lock_destroy(mount_t);
void mount_lock(mount_t);
void mount_unlock(mount_t);
void mount_lock_renames(mount_t);
void mount_unlock_renames(mount_t);
void mount_ref(mount_t, int);
void mount_drop(mount_t, int);
int  mount_refdrain(mount_t);

/* vfs_rootmountalloc should be kept as a private api */
errno_t vfs_rootmountalloc(const char *, const char *, mount_t *mpp);
errno_t vfs_init_io_attributes(vnode_t, mount_t);

int     vfs_mountroot(void);
void    vfs_unmountall(void);
int     safedounmount(struct mount *, int, vfs_context_t);
int     dounmount(struct mount *, int, int, vfs_context_t);

/* xnuy internal api */
void  mount_dropcrossref(mount_t, vnode_t, int);
mount_t mount_lookupby_volfsid(int, int);
mount_t mount_list_lookupby_fsid(fsid_t *, int, int);
void mount_list_add(mount_t);
void mount_list_remove(mount_t);
int  mount_iterref(mount_t, int);
int  mount_isdrained(mount_t, int);
void mount_iterdrop(mount_t);
void mount_iterdrain(mount_t);
void mount_iterreset(mount_t);

/* throttled I/O api */
int throttle_get_io_policy(struct uthread **ut);
extern void throttle_lowpri_io(boolean_t ok_to_sleep);
int throttle_io_will_be_throttled(int lowpri_window_msecs, size_t devbsdunit);

__END_DECLS

#endif /* !_SYS_MOUNT_INTERNAL_H_ */