The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/tmpfs/tmpfs.h

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    1 /*      $NetBSD: tmpfs.h,v 1.26 2007/02/22 06:37:00 thorpej Exp $       */
    2 
    3 /*-
    4  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
    5  * All rights reserved.
    6  *
    7  * This code is derived from software contributed to The NetBSD Foundation
    8  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
    9  * 2005 program.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   30  * POSSIBILITY OF SUCH DAMAGE.
   31  *
   32  * $FreeBSD$
   33  */
   34 
   35 #ifndef _FS_TMPFS_TMPFS_H_
   36 #define _FS_TMPFS_TMPFS_H_
   37 
   38 /* ---------------------------------------------------------------------
   39  * KERNEL-SPECIFIC DEFINITIONS
   40  * --------------------------------------------------------------------- */
   41 #include <sys/dirent.h>
   42 #include <sys/mount.h>
   43 #include <sys/queue.h>
   44 #include <sys/vnode.h>
   45 #include <sys/file.h>
   46 #include <sys/lock.h>
   47 #include <sys/mutex.h>
   48 
   49 /* --------------------------------------------------------------------- */
   50 #include <sys/malloc.h>
   51 #include <sys/systm.h>
   52 #include <sys/vmmeter.h>
   53 #include <vm/swap_pager.h>
   54 
   55 MALLOC_DECLARE(M_TMPFSMNT);
   56 MALLOC_DECLARE(M_TMPFSNAME);
   57 
   58 /* --------------------------------------------------------------------- */
   59 
   60 /*
   61  * Internal representation of a tmpfs directory entry.
   62  */
   63 struct tmpfs_dirent {
   64         TAILQ_ENTRY(tmpfs_dirent)       td_entries;
   65 
   66         /* Length of the name stored in this directory entry.  This avoids
   67          * the need to recalculate it every time the name is used. */
   68         uint16_t                        td_namelen;
   69 
   70         /* The name of the entry, allocated from a string pool.  This
   71         * string is not required to be zero-terminated; therefore, the
   72         * td_namelen field must always be used when accessing its value. */
   73         char *                          td_name;
   74 
   75         /* Pointer to the node this entry refers to.  In case this field
   76          * is NULL, the node is a whiteout. */
   77         struct tmpfs_node *             td_node;
   78 };
   79 
   80 /* A directory in tmpfs holds a sorted list of directory entries, which in
   81  * turn point to other files (which can be directories themselves).
   82  *
   83  * In tmpfs, this list is managed by a tail queue, whose head is defined by
   84  * the struct tmpfs_dir type.
   85  *
   86  * It is imporant to notice that directories do not have entries for . and
   87  * .. as other file systems do.  These can be generated when requested
   88  * based on information available by other means, such as the pointer to
   89  * the node itself in the former case or the pointer to the parent directory
   90  * in the latter case.  This is done to simplify tmpfs's code and, more
   91  * importantly, to remove redundancy. */
   92 TAILQ_HEAD(tmpfs_dir, tmpfs_dirent);
   93 
   94 /* Each entry in a directory has a cookie that identifies it.  Cookies
   95  * supersede offsets within directories because, given how tmpfs stores
   96  * directories in memory, there is no such thing as an offset.  (Emulating
   97  * a real offset could be very difficult.)
   98  * 
   99  * The '.', '..' and the end of directory markers have fixed cookies which
  100  * cannot collide with the cookies generated by other entries.  The cookies
  101  * fot the other entries are generated based on the memory address on which
  102  * stores their information is stored.
  103  *
  104  * Ideally, using the entry's memory pointer as the cookie would be enough
  105  * to represent it and it wouldn't cause collisions in any system.
  106  * Unfortunately, this results in "offsets" with very large values which
  107  * later raise problems in the Linux compatibility layer (and maybe in other
  108  * places) as described in PR kern/32034.  Hence we need to workaround this
  109  * with a rather ugly hack.
  110  *
  111  * Linux 32-bit binaries, unless built with _FILE_OFFSET_BITS=64, have off_t
  112  * set to 'long', which is a 32-bit *signed* long integer.  Regardless of
  113  * the macro value, GLIBC (2.3 at least) always uses the getdents64
  114  * system call (when calling readdir) which internally returns off64_t
  115  * offsets.  In order to make 32-bit binaries work, *GLIBC* converts the
  116  * 64-bit values returned by the kernel to 32-bit ones and aborts with
  117  * EOVERFLOW if the conversion results in values that won't fit in 32-bit
  118  * integers (which it assumes is because the directory is extremely large).
  119  * This wouldn't cause problems if we were dealing with unsigned integers,
  120  * but as we have signed integers, this check fails due to sign expansion.
  121  *
  122  * For example, consider that the kernel returns the 0xc1234567 cookie to
  123  * userspace in a off64_t integer.  Later on, GLIBC casts this value to
  124  * off_t (remember, signed) with code similar to:
  125  *     system call returns the offset in kernel_value;
  126  *     off_t casted_value = kernel_value;
  127  *     if (sizeof(off_t) != sizeof(off64_t) &&
  128  *         kernel_value != casted_value)
  129  *             error!
  130  * In this case, casted_value still has 0xc1234567, but when it is compared
  131  * for equality against kernel_value, it is promoted to a 64-bit integer and
  132  * becomes 0xffffffffc1234567, which is different than 0x00000000c1234567.
  133  * Then, GLIBC assumes this is because the directory is very large.
  134  *
  135  * Given that all the above happens in user-space, we have no control over
  136  * it; therefore we must workaround the issue here.  We do this by
  137  * truncating the pointer value to a 32-bit integer and hope that there
  138  * won't be collisions.  In fact, this will not cause any problems in
  139  * 32-bit platforms but some might arise in 64-bit machines (I'm not sure
  140  * if they can happen at all in practice).
  141  *
  142  * XXX A nicer solution shall be attempted. */
  143 #ifdef _KERNEL
  144 #define TMPFS_DIRCOOKIE_DOT     0
  145 #define TMPFS_DIRCOOKIE_DOTDOT  1
  146 #define TMPFS_DIRCOOKIE_EOF     2
  147 static __inline
  148 off_t
  149 tmpfs_dircookie(struct tmpfs_dirent *de)
  150 {
  151         off_t cookie;
  152 
  153         cookie = ((off_t)(uintptr_t)de >> 1) & 0x7FFFFFFF;
  154         MPASS(cookie != TMPFS_DIRCOOKIE_DOT);
  155         MPASS(cookie != TMPFS_DIRCOOKIE_DOTDOT);
  156         MPASS(cookie != TMPFS_DIRCOOKIE_EOF);
  157 
  158         return cookie;
  159 }
  160 #endif
  161 
  162 /* --------------------------------------------------------------------- */
  163 
  164 /*
  165  * Internal representation of a tmpfs file system node.
  166  *
  167  * This structure is splitted in two parts: one holds attributes common
  168  * to all file types and the other holds data that is only applicable to
  169  * a particular type.  The code must be careful to only access those
  170  * attributes that are actually allowed by the node's type.
  171  *
  172  *
  173  * Below is the key of locks used to protected the fields in the following
  174  * structures.
  175  *
  176  */
  177 struct tmpfs_node {
  178         /* Doubly-linked list entry which links all existing nodes for a
  179          * single file system.  This is provided to ease the removal of
  180          * all nodes during the unmount operation. */
  181         LIST_ENTRY(tmpfs_node)  tn_entries;
  182 
  183         /* The node's type.  Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO',
  184          * 'VLNK', 'VREG' and 'VSOCK' is allowed.  The usage of vnode
  185          * types instead of a custom enumeration is to make things simpler
  186          * and faster, as we do not need to convert between two types. */
  187         enum vtype              tn_type;
  188 
  189         /* Node identifier. */
  190         ino_t                   tn_id;
  191 
  192         /* Node's internal status.  This is used by several file system
  193          * operations to do modifications to the node in a delayed
  194          * fashion. */
  195         int                     tn_status;
  196 #define TMPFS_NODE_ACCESSED     (1 << 1)
  197 #define TMPFS_NODE_MODIFIED     (1 << 2)
  198 #define TMPFS_NODE_CHANGED      (1 << 3)
  199 
  200         /* The node size.  It does not necessarily match the real amount
  201          * of memory consumed by it. */
  202         off_t                   tn_size;
  203 
  204         /* Generic node attributes. */
  205         uid_t                   tn_uid;
  206         gid_t                   tn_gid;
  207         mode_t                  tn_mode;
  208         int                     tn_flags;
  209         nlink_t                 tn_links;
  210         struct timespec         tn_atime;
  211         struct timespec         tn_mtime;
  212         struct timespec         tn_ctime;
  213         struct timespec         tn_birthtime;
  214         unsigned long           tn_gen;
  215 
  216         /* As there is a single vnode for each active file within the
  217          * system, care has to be taken to avoid allocating more than one
  218          * vnode per file.  In order to do this, a bidirectional association
  219          * is kept between vnodes and nodes.
  220          *
  221          * Whenever a vnode is allocated, its v_data field is updated to
  222          * point to the node it references.  At the same time, the node's
  223          * tn_vnode field is modified to point to the new vnode representing
  224          * it.  Further attempts to allocate a vnode for this same node will
  225          * result in returning a new reference to the value stored in
  226          * tn_vnode.
  227          *
  228          * May be NULL when the node is unused (that is, no vnode has been
  229          * allocated for it or it has been reclaimed). */
  230         struct vnode *          tn_vnode;
  231 
  232         /* interlock to protect tn_vpstate */
  233         struct mtx      tn_interlock;
  234 
  235         /* Identify if current node has vnode assiocate with
  236          * or allocating vnode.
  237          */
  238         int             tn_vpstate;
  239 
  240         /* misc data field for different tn_type node */
  241         union {
  242                 /* Valid when tn_type == VBLK || tn_type == VCHR. */
  243                 dev_t                   tn_rdev;
  244 
  245                 /* Valid when tn_type == VDIR. */
  246                 struct tn_dir{
  247                         /* Pointer to the parent directory.  The root
  248                          * directory has a pointer to itself in this field;
  249                          * this property identifies the root node. */
  250                         struct tmpfs_node *     tn_parent;
  251 
  252                         /* Head of a tail-queue that links the contents of
  253                          * the directory together.  See above for a
  254                          * description of its contents. */
  255                         struct tmpfs_dir        tn_dirhead;
  256 
  257                         /* Number and pointer of the first directory entry
  258                          * returned by the readdir operation if it were
  259                          * called again to continue reading data from the
  260                          * same directory as before.  This is used to speed
  261                          * up reads of long directories, assuming that no
  262                          * more than one read is in progress at a given time.
  263                          * Otherwise, these values are discarded and a linear
  264                          * scan is performed from the beginning up to the
  265                          * point where readdir starts returning values. */
  266                         off_t                   tn_readdir_lastn;
  267                         struct tmpfs_dirent *   tn_readdir_lastp;
  268                 }tn_dir;
  269 
  270                 /* Valid when tn_type == VLNK. */
  271                 /* The link's target, allocated from a string pool. */
  272                 char *                  tn_link;
  273 
  274                 /* Valid when tn_type == VREG. */
  275                 struct tn_reg {
  276                         /* The contents of regular files stored in a tmpfs
  277                          * file system are represented by a single anonymous
  278                          * memory object (aobj, for short).  The aobj provides
  279                          * direct access to any position within the file,
  280                          * because its contents are always mapped in a
  281                          * contiguous region of virtual memory.  It is a task
  282                          * of the memory management subsystem (see uvm(9)) to
  283                          * issue the required page ins or page outs whenever
  284                          * a position within the file is accessed. */
  285                         vm_object_t             tn_aobj;
  286 
  287                 }tn_reg;
  288 
  289                 /* Valid when tn_type = VFIFO */
  290                 struct tn_fifo {
  291                         fo_rdwr_t               *tn_fo_read;
  292                         fo_rdwr_t               *tn_fo_write;
  293                 }tn_fifo;
  294         }tn_spec;
  295 };
  296 LIST_HEAD(tmpfs_node_list, tmpfs_node);
  297 
  298 #define tn_rdev tn_spec.tn_rdev
  299 #define tn_dir tn_spec.tn_dir
  300 #define tn_link tn_spec.tn_link
  301 #define tn_reg tn_spec.tn_reg
  302 #define tn_fifo tn_spec.tn_fifo
  303 
  304 #define TMPFS_NODE_LOCK(node) mtx_lock(&(node)->tn_interlock)
  305 #define TMPFS_NODE_UNLOCK(node) mtx_unlock(&(node)->tn_interlock)
  306 #define TMPFS_NODE_MTX(node) (&(node)->tn_interlock)
  307 
  308 #ifdef INVARIANTS
  309 #define TMPFS_ASSERT_LOCKED(node) do {                                  \
  310                 MPASS(node != NULL);                                    \
  311                 MPASS(node->tn_vnode != NULL);                          \
  312                 if (!VOP_ISLOCKED(node->tn_vnode) &&                    \
  313                     !mtx_owned(TMPFS_NODE_MTX(node)))                   \
  314                         panic("tmpfs: node is not locked: %p", node);   \
  315         } while (0)
  316 #define TMPFS_ASSERT_ELOCKED(node) do {                                 \
  317                 MPASS((node) != NULL);                                  \
  318                 MPASS((node)->tn_vnode != NULL);                        \
  319                 mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED);             \
  320                 ASSERT_VOP_LOCKED((node)->tn_vnode, "tmpfs");           \
  321         } while (0)
  322 #else
  323 #define TMPFS_ASSERT_LOCKED(node) (void)0
  324 #define TMPFS_ASSERT_ELOCKED(node) (void)0
  325 #endif
  326 
  327 #define TMPFS_VNODE_ALLOCATING  1
  328 #define TMPFS_VNODE_WANT        2
  329 #define TMPFS_VNODE_DOOMED      4
  330 #define TMPFS_VNODE_WRECLAIM    8
  331 /* --------------------------------------------------------------------- */
  332 
  333 /*
  334  * Internal representation of a tmpfs mount point.
  335  */
  336 struct tmpfs_mount {
  337         /* Maximum number of memory pages available for use by the file
  338          * system, set during mount time.  This variable must never be
  339          * used directly as it may be bigger than the current amount of
  340          * free memory; in the extreme case, it will hold the SIZE_MAX
  341          * value. */
  342         size_t                  tm_pages_max;
  343 
  344         /* Number of pages in use by the file system. */
  345         size_t                  tm_pages_used;
  346 
  347         /* Pointer to the node representing the root directory of this
  348          * file system. */
  349         struct tmpfs_node *     tm_root;
  350 
  351         /* Maximum number of possible nodes for this file system; set
  352          * during mount time.  We need a hard limit on the maximum number
  353          * of nodes to avoid allocating too much of them; their objects
  354          * cannot be released until the file system is unmounted.
  355          * Otherwise, we could easily run out of memory by creating lots
  356          * of empty files and then simply removing them. */
  357         ino_t                   tm_nodes_max;
  358 
  359         /* unrhdr used to allocate inode numbers */
  360         struct unrhdr *         tm_ino_unr;
  361 
  362         /* Number of nodes currently that are in use. */
  363         ino_t                   tm_nodes_inuse;
  364 
  365         /* maximum representable file size */
  366         u_int64_t               tm_maxfilesize;
  367 
  368         /* Nodes are organized in two different lists.  The used list
  369          * contains all nodes that are currently used by the file system;
  370          * i.e., they refer to existing files.  The available list contains
  371          * all nodes that are currently available for use by new files.
  372          * Nodes must be kept in this list (instead of deleting them)
  373          * because we need to keep track of their generation number (tn_gen
  374          * field).
  375          *
  376          * Note that nodes are lazily allocated: if the available list is
  377          * empty and we have enough space to create more nodes, they will be
  378          * created and inserted in the used list.  Once these are released,
  379          * they will go into the available list, remaining alive until the
  380          * file system is unmounted. */
  381         struct tmpfs_node_list  tm_nodes_used;
  382 
  383         /* All node lock to protect the node list and tmp_pages_used */
  384         struct mtx allnode_lock;
  385 
  386         /* Pools used to store file system meta data.  These are not shared
  387          * across several instances of tmpfs for the reasons described in
  388          * tmpfs_pool.c. */
  389         uma_zone_t              tm_dirent_pool;
  390         uma_zone_t              tm_node_pool;
  391 
  392         /* Read-only status. */
  393         int                     tm_ronly;
  394 };
  395 #define TMPFS_LOCK(tm) mtx_lock(&(tm)->allnode_lock)
  396 #define TMPFS_UNLOCK(tm) mtx_unlock(&(tm)->allnode_lock)
  397 
  398 /* --------------------------------------------------------------------- */
  399 
  400 /*
  401  * This structure maps a file identifier to a tmpfs node.  Used by the
  402  * NFS code.
  403  */
  404 struct tmpfs_fid {
  405         uint16_t                tf_len;
  406         uint16_t                tf_pad;
  407         ino_t                   tf_id;
  408         unsigned long           tf_gen;
  409 };
  410 
  411 /* --------------------------------------------------------------------- */
  412 
  413 #ifdef _KERNEL
  414 /*
  415  * Prototypes for tmpfs_subr.c.
  416  */
  417 
  418 int     tmpfs_alloc_node(struct tmpfs_mount *, enum vtype,
  419             uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *,
  420             char *, dev_t, struct tmpfs_node **);
  421 void    tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *);
  422 int     tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *,
  423             const char *, uint16_t, struct tmpfs_dirent **);
  424 void    tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *,
  425             boolean_t);
  426 int     tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, int,
  427             struct vnode **);
  428 void    tmpfs_free_vp(struct vnode *);
  429 int     tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *,
  430             struct componentname *, char *);
  431 void    tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *);
  432 void    tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *);
  433 struct tmpfs_dirent *   tmpfs_dir_lookup(struct tmpfs_node *node,
  434                             struct tmpfs_node *f,
  435                             struct componentname *cnp);
  436 int     tmpfs_dir_getdotdent(struct tmpfs_node *, struct uio *);
  437 int     tmpfs_dir_getdotdotdent(struct tmpfs_node *, struct uio *);
  438 struct tmpfs_dirent *   tmpfs_dir_lookupbycookie(struct tmpfs_node *, off_t);
  439 int     tmpfs_dir_getdents(struct tmpfs_node *, struct uio *, off_t *);
  440 int     tmpfs_dir_whiteout_add(struct vnode *, struct componentname *);
  441 void    tmpfs_dir_whiteout_remove(struct vnode *, struct componentname *);
  442 int     tmpfs_reg_resize(struct vnode *, off_t, boolean_t);
  443 int     tmpfs_chflags(struct vnode *, int, struct ucred *, struct thread *);
  444 int     tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct thread *);
  445 int     tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *,
  446             struct thread *);
  447 int     tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct thread *);
  448 int     tmpfs_chtimes(struct vnode *, struct timespec *, struct timespec *,
  449             struct timespec *, int, struct ucred *, struct thread *);
  450 void    tmpfs_itimes(struct vnode *, const struct timespec *,
  451             const struct timespec *);
  452 
  453 void    tmpfs_update(struct vnode *);
  454 int     tmpfs_truncate(struct vnode *, off_t);
  455 
  456 /* --------------------------------------------------------------------- */
  457 
  458 /*
  459  * Convenience macros to simplify some logical expressions.
  460  */
  461 #define IMPLIES(a, b) (!(a) || (b))
  462 #define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a))
  463 
  464 /* --------------------------------------------------------------------- */
  465 
  466 /*
  467  * Checks that the directory entry pointed by 'de' matches the name 'name'
  468  * with a length of 'len'.
  469  */
  470 #define TMPFS_DIRENT_MATCHES(de, name, len) \
  471     (de->td_namelen == (uint16_t)len && \
  472     bcmp((de)->td_name, (name), (de)->td_namelen) == 0)
  473 
  474 /* --------------------------------------------------------------------- */
  475 
  476 /*
  477  * Ensures that the node pointed by 'node' is a directory and that its
  478  * contents are consistent with respect to directories.
  479  */
  480 #define TMPFS_VALIDATE_DIR(node) \
  481     MPASS((node)->tn_type == VDIR); \
  482     MPASS((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \
  483     MPASS((node)->tn_dir.tn_readdir_lastp == NULL || \
  484         tmpfs_dircookie((node)->tn_dir.tn_readdir_lastp) == (node)->tn_dir.tn_readdir_lastn);
  485 
  486 /* --------------------------------------------------------------------- */
  487 
  488 /*
  489  * Memory management stuff.
  490  */
  491 
  492 /*
  493  * Amount of memory pages to reserve for the system (e.g., to not use by
  494  * tmpfs).
  495  */
  496 #define TMPFS_PAGES_MINRESERVED         (4 * 1024 * 1024 / PAGE_SIZE)
  497 
  498 size_t tmpfs_mem_avail(void);
  499 
  500 size_t tmpfs_pages_used(struct tmpfs_mount *tmp);
  501 
  502 #endif
  503 
  504 /* --------------------------------------------------------------------- */
  505 
  506 /*
  507  * Macros/functions to convert from generic data structures to tmpfs
  508  * specific ones.
  509  */
  510 
  511 static inline
  512 struct tmpfs_mount *
  513 VFS_TO_TMPFS(struct mount *mp)
  514 {
  515         struct tmpfs_mount *tmp;
  516 
  517         MPASS((mp) != NULL && (mp)->mnt_data != NULL);
  518         tmp = (struct tmpfs_mount *)(mp)->mnt_data;
  519         return tmp;
  520 }
  521 
  522 static inline
  523 struct tmpfs_node *
  524 VP_TO_TMPFS_NODE(struct vnode *vp)
  525 {
  526         struct tmpfs_node *node;
  527 
  528         MPASS((vp) != NULL && (vp)->v_data != NULL);
  529         node = (struct tmpfs_node *)vp->v_data;
  530         return node;
  531 }
  532 
  533 static inline
  534 struct tmpfs_node *
  535 VP_TO_TMPFS_DIR(struct vnode *vp)
  536 {
  537         struct tmpfs_node *node;
  538 
  539         node = VP_TO_TMPFS_NODE(vp);
  540         TMPFS_VALIDATE_DIR(node);
  541         return node;
  542 }
  543 
  544 #endif /* _FS_TMPFS_TMPFS_H_ */

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