tmpfs_subr.c

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    1 /*      $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $       */
    2 
    3 /*-
    4  * Copyright (c) 2005 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 
   33 /*
   34  * Efficient memory file system supporting functions.
   35  */
   36 #include <sys/cdefs.h>
   37 __FBSDID("$FreeBSD: releng/9.0/sys/fs/tmpfs/tmpfs_subr.c 223677 2011-06-29 16:40:41Z alc $");
   38 
   39 #include <sys/param.h>
   40 #include <sys/namei.h>
   41 #include <sys/priv.h>
   42 #include <sys/proc.h>
   43 #include <sys/stat.h>
   44 #include <sys/systm.h>
   45 #include <sys/vnode.h>
   46 #include <sys/vmmeter.h>
   47 
   48 #include <vm/vm.h>
   49 #include <vm/vm_object.h>
   50 #include <vm/vm_page.h>
   51 #include <vm/vm_pager.h>
   52 #include <vm/vm_extern.h>
   53 
   54 #include <fs/tmpfs/tmpfs.h>
   55 #include <fs/tmpfs/tmpfs_fifoops.h>
   56 #include <fs/tmpfs/tmpfs_vnops.h>
   57 
   58 /* --------------------------------------------------------------------- */
   59 
   60 /*
   61  * Allocates a new node of type 'type' inside the 'tmp' mount point, with
   62  * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
   63  * using the credentials of the process 'p'.
   64  *
   65  * If the node type is set to 'VDIR', then the parent parameter must point
   66  * to the parent directory of the node being created.  It may only be NULL
   67  * while allocating the root node.
   68  *
   69  * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
   70  * specifies the device the node represents.
   71  *
   72  * If the node type is set to 'VLNK', then the parameter target specifies
   73  * the file name of the target file for the symbolic link that is being
   74  * created.
   75  *
   76  * Note that new nodes are retrieved from the available list if it has
   77  * items or, if it is empty, from the node pool as long as there is enough
   78  * space to create them.
   79  *
   80  * Returns zero on success or an appropriate error code on failure.
   81  */
   82 int
   83 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
   84     uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent,
   85     char *target, dev_t rdev, struct tmpfs_node **node)
   86 {
   87         struct tmpfs_node *nnode;
   88 
   89         /* If the root directory of the 'tmp' file system is not yet
   90          * allocated, this must be the request to do it. */
   91         MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR));
   92 
   93         MPASS(IFF(type == VLNK, target != NULL));
   94         MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL));
   95 
   96         if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
   97                 return (ENOSPC);
   98 
   99         nnode = (struct tmpfs_node *)uma_zalloc_arg(
  100                                 tmp->tm_node_pool, tmp, M_WAITOK);
  101 
  102         /* Generic initialization. */
  103         nnode->tn_type = type;
  104         vfs_timestamp(&nnode->tn_atime);
  105         nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime =
  106             nnode->tn_atime;
  107         nnode->tn_uid = uid;
  108         nnode->tn_gid = gid;
  109         nnode->tn_mode = mode;
  110         nnode->tn_id = alloc_unr(tmp->tm_ino_unr);
  111 
  112         /* Type-specific initialization. */
  113         switch (nnode->tn_type) {
  114         case VBLK:
  115         case VCHR:
  116                 nnode->tn_rdev = rdev;
  117                 break;
  118 
  119         case VDIR:
  120                 TAILQ_INIT(&nnode->tn_dir.tn_dirhead);
  121                 MPASS(parent != nnode);
  122                 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL));
  123                 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent;
  124                 nnode->tn_dir.tn_readdir_lastn = 0;
  125                 nnode->tn_dir.tn_readdir_lastp = NULL;
  126                 nnode->tn_links++;
  127                 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent);
  128                 nnode->tn_dir.tn_parent->tn_links++;
  129                 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent);
  130                 break;
  131 
  132         case VFIFO:
  133                 /* FALLTHROUGH */
  134         case VSOCK:
  135                 break;
  136 
  137         case VLNK:
  138                 MPASS(strlen(target) < MAXPATHLEN);
  139                 nnode->tn_size = strlen(target);
  140                 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME,
  141                     M_WAITOK);
  142                 memcpy(nnode->tn_link, target, nnode->tn_size);
  143                 break;
  144 
  145         case VREG:
  146                 nnode->tn_reg.tn_aobj =
  147                     vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0,
  148                         NULL /* XXXKIB - tmpfs needs swap reservation */);
  149                 break;
  150 
  151         default:
  152                 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
  153         }
  154 
  155         TMPFS_LOCK(tmp);
  156         LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
  157         tmp->tm_nodes_inuse++;
  158         TMPFS_UNLOCK(tmp);
  159 
  160         *node = nnode;
  161         return 0;
  162 }
  163 
  164 /* --------------------------------------------------------------------- */
  165 
  166 /*
  167  * Destroys the node pointed to by node from the file system 'tmp'.
  168  * If the node does not belong to the given mount point, the results are
  169  * unpredicted.
  170  *
  171  * If the node references a directory; no entries are allowed because
  172  * their removal could need a recursive algorithm, something forbidden in
  173  * kernel space.  Furthermore, there is not need to provide such
  174  * functionality (recursive removal) because the only primitives offered
  175  * to the user are the removal of empty directories and the deletion of
  176  * individual files.
  177  *
  178  * Note that nodes are not really deleted; in fact, when a node has been
  179  * allocated, it cannot be deleted during the whole life of the file
  180  * system.  Instead, they are moved to the available list and remain there
  181  * until reused.
  182  */
  183 void
  184 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
  185 {
  186         vm_object_t uobj;
  187 
  188 #ifdef INVARIANTS
  189         TMPFS_NODE_LOCK(node);
  190         MPASS(node->tn_vnode == NULL);
  191         MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
  192         TMPFS_NODE_UNLOCK(node);
  193 #endif
  194 
  195         TMPFS_LOCK(tmp);
  196         LIST_REMOVE(node, tn_entries);
  197         tmp->tm_nodes_inuse--;
  198         TMPFS_UNLOCK(tmp);
  199 
  200         switch (node->tn_type) {
  201         case VNON:
  202                 /* Do not do anything.  VNON is provided to let the
  203                  * allocation routine clean itself easily by avoiding
  204                  * duplicating code in it. */
  205                 /* FALLTHROUGH */
  206         case VBLK:
  207                 /* FALLTHROUGH */
  208         case VCHR:
  209                 /* FALLTHROUGH */
  210         case VDIR:
  211                 /* FALLTHROUGH */
  212         case VFIFO:
  213                 /* FALLTHROUGH */
  214         case VSOCK:
  215                 break;
  216 
  217         case VLNK:
  218                 free(node->tn_link, M_TMPFSNAME);
  219                 break;
  220 
  221         case VREG:
  222                 uobj = node->tn_reg.tn_aobj;
  223                 if (uobj != NULL) {
  224                         TMPFS_LOCK(tmp);
  225                         tmp->tm_pages_used -= uobj->size;
  226                         TMPFS_UNLOCK(tmp);
  227                         vm_object_deallocate(uobj);
  228                 }
  229                 break;
  230 
  231         default:
  232                 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
  233         }
  234 
  235         free_unr(tmp->tm_ino_unr, node->tn_id);
  236         uma_zfree(tmp->tm_node_pool, node);
  237 }
  238 
  239 /* --------------------------------------------------------------------- */
  240 
  241 /*
  242  * Allocates a new directory entry for the node node with a name of name.
  243  * The new directory entry is returned in *de.
  244  *
  245  * The link count of node is increased by one to reflect the new object
  246  * referencing it.
  247  *
  248  * Returns zero on success or an appropriate error code on failure.
  249  */
  250 int
  251 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
  252     const char *name, uint16_t len, struct tmpfs_dirent **de)
  253 {
  254         struct tmpfs_dirent *nde;
  255 
  256         nde = (struct tmpfs_dirent *)uma_zalloc(
  257                                         tmp->tm_dirent_pool, M_WAITOK);
  258         nde->td_name = malloc(len, M_TMPFSNAME, M_WAITOK);
  259         nde->td_namelen = len;
  260         memcpy(nde->td_name, name, len);
  261 
  262         nde->td_node = node;
  263         if (node != NULL)
  264                 node->tn_links++;
  265 
  266         *de = nde;
  267 
  268         return 0;
  269 }
  270 
  271 /* --------------------------------------------------------------------- */
  272 
  273 /*
  274  * Frees a directory entry.  It is the caller's responsibility to destroy
  275  * the node referenced by it if needed.
  276  *
  277  * The link count of node is decreased by one to reflect the removal of an
  278  * object that referenced it.  This only happens if 'node_exists' is true;
  279  * otherwise the function will not access the node referred to by the
  280  * directory entry, as it may already have been released from the outside.
  281  */
  282 void
  283 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de,
  284     boolean_t node_exists)
  285 {
  286         if (node_exists) {
  287                 struct tmpfs_node *node;
  288 
  289                 node = de->td_node;
  290                 if (node != NULL) {
  291                         MPASS(node->tn_links > 0);
  292                         node->tn_links--;
  293                 }
  294         }
  295 
  296         free(de->td_name, M_TMPFSNAME);
  297         uma_zfree(tmp->tm_dirent_pool, de);
  298 }
  299 
  300 /* --------------------------------------------------------------------- */
  301 
  302 /*
  303  * Allocates a new vnode for the node node or returns a new reference to
  304  * an existing one if the node had already a vnode referencing it.  The
  305  * resulting locked vnode is returned in *vpp.
  306  *
  307  * Returns zero on success or an appropriate error code on failure.
  308  */
  309 int
  310 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag,
  311     struct vnode **vpp)
  312 {
  313         int error = 0;
  314         struct vnode *vp;
  315 
  316 loop:
  317         TMPFS_NODE_LOCK(node);
  318         if ((vp = node->tn_vnode) != NULL) {
  319                 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
  320                 VI_LOCK(vp);
  321                 TMPFS_NODE_UNLOCK(node);
  322                 vholdl(vp);
  323                 (void) vget(vp, lkflag | LK_INTERLOCK | LK_RETRY, curthread);
  324                 vdrop(vp);
  325 
  326                 /*
  327                  * Make sure the vnode is still there after
  328                  * getting the interlock to avoid racing a free.
  329                  */
  330                 if (node->tn_vnode == NULL || node->tn_vnode != vp) {
  331                         vput(vp);
  332                         goto loop;
  333                 }
  334 
  335                 goto out;
  336         }
  337 
  338         if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) ||
  339             (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) {
  340                 TMPFS_NODE_UNLOCK(node);
  341                 error = ENOENT;
  342                 vp = NULL;
  343                 goto out;
  344         }
  345 
  346         /*
  347          * otherwise lock the vp list while we call getnewvnode
  348          * since that can block.
  349          */
  350         if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
  351                 node->tn_vpstate |= TMPFS_VNODE_WANT;
  352                 error = msleep((caddr_t) &node->tn_vpstate,
  353                     TMPFS_NODE_MTX(node), PDROP | PCATCH,
  354                     "tmpfs_alloc_vp", 0);
  355                 if (error)
  356                         return error;
  357 
  358                 goto loop;
  359         } else
  360                 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
  361         
  362         TMPFS_NODE_UNLOCK(node);
  363 
  364         /* Get a new vnode and associate it with our node. */
  365         error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp);
  366         if (error != 0)
  367                 goto unlock;
  368         MPASS(vp != NULL);
  369 
  370         (void) vn_lock(vp, lkflag | LK_RETRY);
  371 
  372         vp->v_data = node;
  373         vp->v_type = node->tn_type;
  374 
  375         /* Type-specific initialization. */
  376         switch (node->tn_type) {
  377         case VBLK:
  378                 /* FALLTHROUGH */
  379         case VCHR:
  380                 /* FALLTHROUGH */
  381         case VLNK:
  382                 /* FALLTHROUGH */
  383         case VREG:
  384                 /* FALLTHROUGH */
  385         case VSOCK:
  386                 break;
  387         case VFIFO:
  388                 vp->v_op = &tmpfs_fifoop_entries;
  389                 break;
  390         case VDIR:
  391                 MPASS(node->tn_dir.tn_parent != NULL);
  392                 if (node->tn_dir.tn_parent == node)
  393                         vp->v_vflag |= VV_ROOT;
  394                 break;
  395 
  396         default:
  397                 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
  398         }
  399 
  400         vnode_pager_setsize(vp, node->tn_size);
  401         error = insmntque(vp, mp);
  402         if (error)
  403                 vp = NULL;
  404 
  405 unlock:
  406         TMPFS_NODE_LOCK(node);
  407 
  408         MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
  409         node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
  410         node->tn_vnode = vp;
  411 
  412         if (node->tn_vpstate & TMPFS_VNODE_WANT) {
  413                 node->tn_vpstate &= ~TMPFS_VNODE_WANT;
  414                 TMPFS_NODE_UNLOCK(node);
  415                 wakeup((caddr_t) &node->tn_vpstate);
  416         } else
  417                 TMPFS_NODE_UNLOCK(node);
  418 
  419 out:
  420         *vpp = vp;
  421 
  422         MPASS(IFF(error == 0, *vpp != NULL && VOP_ISLOCKED(*vpp)));
  423 #ifdef INVARIANTS
  424         TMPFS_NODE_LOCK(node);
  425         MPASS(*vpp == node->tn_vnode);
  426         TMPFS_NODE_UNLOCK(node);
  427 #endif
  428 
  429         return error;
  430 }
  431 
  432 /* --------------------------------------------------------------------- */
  433 
  434 /*
  435  * Destroys the association between the vnode vp and the node it
  436  * references.
  437  */
  438 void
  439 tmpfs_free_vp(struct vnode *vp)
  440 {
  441         struct tmpfs_node *node;
  442 
  443         node = VP_TO_TMPFS_NODE(vp);
  444 
  445         mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED);
  446         node->tn_vnode = NULL;
  447         vp->v_data = NULL;
  448 }
  449 
  450 /* --------------------------------------------------------------------- */
  451 
  452 /*
  453  * Allocates a new file of type 'type' and adds it to the parent directory
  454  * 'dvp'; this addition is done using the component name given in 'cnp'.
  455  * The ownership of the new file is automatically assigned based on the
  456  * credentials of the caller (through 'cnp'), the group is set based on
  457  * the parent directory and the mode is determined from the 'vap' argument.
  458  * If successful, *vpp holds a vnode to the newly created file and zero
  459  * is returned.  Otherwise *vpp is NULL and the function returns an
  460  * appropriate error code.
  461  */
  462 int
  463 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
  464     struct componentname *cnp, char *target)
  465 {
  466         int error;
  467         struct tmpfs_dirent *de;
  468         struct tmpfs_mount *tmp;
  469         struct tmpfs_node *dnode;
  470         struct tmpfs_node *node;
  471         struct tmpfs_node *parent;
  472 
  473         MPASS(VOP_ISLOCKED(dvp));
  474         MPASS(cnp->cn_flags & HASBUF);
  475 
  476         tmp = VFS_TO_TMPFS(dvp->v_mount);
  477         dnode = VP_TO_TMPFS_DIR(dvp);
  478         *vpp = NULL;
  479 
  480         /* If the entry we are creating is a directory, we cannot overflow
  481          * the number of links of its parent, because it will get a new
  482          * link. */
  483         if (vap->va_type == VDIR) {
  484                 /* Ensure that we do not overflow the maximum number of links
  485                  * imposed by the system. */
  486                 MPASS(dnode->tn_links <= LINK_MAX);
  487                 if (dnode->tn_links == LINK_MAX) {
  488                         error = EMLINK;
  489                         goto out;
  490                 }
  491 
  492                 parent = dnode;
  493                 MPASS(parent != NULL);
  494         } else
  495                 parent = NULL;
  496 
  497         /* Allocate a node that represents the new file. */
  498         error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid,
  499             dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node);
  500         if (error != 0)
  501                 goto out;
  502 
  503         /* Allocate a directory entry that points to the new file. */
  504         error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen,
  505             &de);
  506         if (error != 0) {
  507                 tmpfs_free_node(tmp, node);
  508                 goto out;
  509         }
  510 
  511         /* Allocate a vnode for the new file. */
  512         error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp);
  513         if (error != 0) {
  514                 tmpfs_free_dirent(tmp, de, TRUE);
  515                 tmpfs_free_node(tmp, node);
  516                 goto out;
  517         }
  518 
  519         /* Now that all required items are allocated, we can proceed to
  520          * insert the new node into the directory, an operation that
  521          * cannot fail. */
  522         if (cnp->cn_flags & ISWHITEOUT)
  523                 tmpfs_dir_whiteout_remove(dvp, cnp);
  524         tmpfs_dir_attach(dvp, de);
  525 
  526 out:
  527 
  528         return error;
  529 }
  530 
  531 /* --------------------------------------------------------------------- */
  532 
  533 /*
  534  * Attaches the directory entry de to the directory represented by vp.
  535  * Note that this does not change the link count of the node pointed by
  536  * the directory entry, as this is done by tmpfs_alloc_dirent.
  537  */
  538 void
  539 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de)
  540 {
  541         struct tmpfs_node *dnode;
  542 
  543         ASSERT_VOP_ELOCKED(vp, __func__);
  544         dnode = VP_TO_TMPFS_DIR(vp);
  545         TAILQ_INSERT_TAIL(&dnode->tn_dir.tn_dirhead, de, td_entries);
  546         dnode->tn_size += sizeof(struct tmpfs_dirent);
  547         dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
  548             TMPFS_NODE_MODIFIED;
  549 }
  550 
  551 /* --------------------------------------------------------------------- */
  552 
  553 /*
  554  * Detaches the directory entry de from the directory represented by vp.
  555  * Note that this does not change the link count of the node pointed by
  556  * the directory entry, as this is done by tmpfs_free_dirent.
  557  */
  558 void
  559 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de)
  560 {
  561         struct tmpfs_node *dnode;
  562 
  563         ASSERT_VOP_ELOCKED(vp, __func__);
  564         dnode = VP_TO_TMPFS_DIR(vp);
  565 
  566         if (dnode->tn_dir.tn_readdir_lastp == de) {
  567                 dnode->tn_dir.tn_readdir_lastn = 0;
  568                 dnode->tn_dir.tn_readdir_lastp = NULL;
  569         }
  570 
  571         TAILQ_REMOVE(&dnode->tn_dir.tn_dirhead, de, td_entries);
  572         dnode->tn_size -= sizeof(struct tmpfs_dirent);
  573         dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
  574             TMPFS_NODE_MODIFIED;
  575 }
  576 
  577 /* --------------------------------------------------------------------- */
  578 
  579 /*
  580  * Looks for a directory entry in the directory represented by node.
  581  * 'cnp' describes the name of the entry to look for.  Note that the .
  582  * and .. components are not allowed as they do not physically exist
  583  * within directories.
  584  *
  585  * Returns a pointer to the entry when found, otherwise NULL.
  586  */
  587 struct tmpfs_dirent *
  588 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
  589     struct componentname *cnp)
  590 {
  591         boolean_t found;
  592         struct tmpfs_dirent *de;
  593 
  594         MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.'));
  595         MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' &&
  596             cnp->cn_nameptr[1] == '.')));
  597         TMPFS_VALIDATE_DIR(node);
  598 
  599         found = 0;
  600         TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) {
  601                 if (f != NULL && de->td_node != f)
  602                     continue;
  603                 MPASS(cnp->cn_namelen < 0xffff);
  604                 if (de->td_namelen == (uint16_t)cnp->cn_namelen &&
  605                     bcmp(de->td_name, cnp->cn_nameptr, de->td_namelen) == 0) {
  606                         found = 1;
  607                         break;
  608                 }
  609         }
  610         node->tn_status |= TMPFS_NODE_ACCESSED;
  611 
  612         return found ? de : NULL;
  613 }
  614 
  615 /* --------------------------------------------------------------------- */
  616 
  617 /*
  618  * Helper function for tmpfs_readdir.  Creates a '.' entry for the given
  619  * directory and returns it in the uio space.  The function returns 0
  620  * on success, -1 if there was not enough space in the uio structure to
  621  * hold the directory entry or an appropriate error code if another
  622  * error happens.
  623  */
  624 int
  625 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
  626 {
  627         int error;
  628         struct dirent dent;
  629 
  630         TMPFS_VALIDATE_DIR(node);
  631         MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
  632 
  633         dent.d_fileno = node->tn_id;
  634         dent.d_type = DT_DIR;
  635         dent.d_namlen = 1;
  636         dent.d_name[0] = '.';
  637         dent.d_name[1] = '\0';
  638         dent.d_reclen = GENERIC_DIRSIZ(&dent);
  639 
  640         if (dent.d_reclen > uio->uio_resid)
  641                 error = -1;
  642         else {
  643                 error = uiomove(&dent, dent.d_reclen, uio);
  644                 if (error == 0)
  645                         uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
  646         }
  647 
  648         node->tn_status |= TMPFS_NODE_ACCESSED;
  649 
  650         return error;
  651 }
  652 
  653 /* --------------------------------------------------------------------- */
  654 
  655 /*
  656  * Helper function for tmpfs_readdir.  Creates a '..' entry for the given
  657  * directory and returns it in the uio space.  The function returns 0
  658  * on success, -1 if there was not enough space in the uio structure to
  659  * hold the directory entry or an appropriate error code if another
  660  * error happens.
  661  */
  662 int
  663 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio)
  664 {
  665         int error;
  666         struct dirent dent;
  667 
  668         TMPFS_VALIDATE_DIR(node);
  669         MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
  670 
  671         /*
  672          * Return ENOENT if the current node is already removed.
  673          */
  674         TMPFS_ASSERT_LOCKED(node);
  675         if (node->tn_dir.tn_parent == NULL) {
  676                 return (ENOENT);
  677         }
  678 
  679         TMPFS_NODE_LOCK(node->tn_dir.tn_parent);
  680         dent.d_fileno = node->tn_dir.tn_parent->tn_id;
  681         TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent);
  682 
  683         dent.d_type = DT_DIR;
  684         dent.d_namlen = 2;
  685         dent.d_name[0] = '.';
  686         dent.d_name[1] = '.';
  687         dent.d_name[2] = '\0';
  688         dent.d_reclen = GENERIC_DIRSIZ(&dent);
  689 
  690         if (dent.d_reclen > uio->uio_resid)
  691                 error = -1;
  692         else {
  693                 error = uiomove(&dent, dent.d_reclen, uio);
  694                 if (error == 0) {
  695                         struct tmpfs_dirent *de;
  696 
  697                         de = TAILQ_FIRST(&node->tn_dir.tn_dirhead);
  698                         if (de == NULL)
  699                                 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
  700                         else
  701                                 uio->uio_offset = tmpfs_dircookie(de);
  702                 }
  703         }
  704 
  705         node->tn_status |= TMPFS_NODE_ACCESSED;
  706 
  707         return error;
  708 }
  709 
  710 /* --------------------------------------------------------------------- */
  711 
  712 /*
  713  * Lookup a directory entry by its associated cookie.
  714  */
  715 struct tmpfs_dirent *
  716 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie)
  717 {
  718         struct tmpfs_dirent *de;
  719 
  720         if (cookie == node->tn_dir.tn_readdir_lastn &&
  721             node->tn_dir.tn_readdir_lastp != NULL) {
  722                 return node->tn_dir.tn_readdir_lastp;
  723         }
  724 
  725         TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) {
  726                 if (tmpfs_dircookie(de) == cookie) {
  727                         break;
  728                 }
  729         }
  730 
  731         return de;
  732 }
  733 
  734 /* --------------------------------------------------------------------- */
  735 
  736 /*
  737  * Helper function for tmpfs_readdir.  Returns as much directory entries
  738  * as can fit in the uio space.  The read starts at uio->uio_offset.
  739  * The function returns 0 on success, -1 if there was not enough space
  740  * in the uio structure to hold the directory entry or an appropriate
  741  * error code if another error happens.
  742  */
  743 int
  744 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp)
  745 {
  746         int error;
  747         off_t startcookie;
  748         struct tmpfs_dirent *de;
  749 
  750         TMPFS_VALIDATE_DIR(node);
  751 
  752         /* Locate the first directory entry we have to return.  We have cached
  753          * the last readdir in the node, so use those values if appropriate.
  754          * Otherwise do a linear scan to find the requested entry. */
  755         startcookie = uio->uio_offset;
  756         MPASS(startcookie != TMPFS_DIRCOOKIE_DOT);
  757         MPASS(startcookie != TMPFS_DIRCOOKIE_DOTDOT);
  758         if (startcookie == TMPFS_DIRCOOKIE_EOF) {
  759                 return 0;
  760         } else {
  761                 de = tmpfs_dir_lookupbycookie(node, startcookie);
  762         }
  763         if (de == NULL) {
  764                 return EINVAL;
  765         }
  766 
  767         /* Read as much entries as possible; i.e., until we reach the end of
  768          * the directory or we exhaust uio space. */
  769         do {
  770                 struct dirent d;
  771 
  772                 /* Create a dirent structure representing the current
  773                  * tmpfs_node and fill it. */
  774                 if (de->td_node == NULL) {
  775                         d.d_fileno = 1;
  776                         d.d_type = DT_WHT;
  777                 } else {
  778                         d.d_fileno = de->td_node->tn_id;
  779                         switch (de->td_node->tn_type) {
  780                         case VBLK:
  781                                 d.d_type = DT_BLK;
  782                                 break;
  783 
  784                         case VCHR:
  785                                 d.d_type = DT_CHR;
  786                                 break;
  787 
  788                         case VDIR:
  789                                 d.d_type = DT_DIR;
  790                                 break;
  791 
  792                         case VFIFO:
  793                                 d.d_type = DT_FIFO;
  794                                 break;
  795 
  796                         case VLNK:
  797                                 d.d_type = DT_LNK;
  798                                 break;
  799 
  800                         case VREG:
  801                                 d.d_type = DT_REG;
  802                                 break;
  803 
  804                         case VSOCK:
  805                                 d.d_type = DT_SOCK;
  806                                 break;
  807 
  808                         default:
  809                                 panic("tmpfs_dir_getdents: type %p %d",
  810                                     de->td_node, (int)de->td_node->tn_type);
  811                         }
  812                 }
  813                 d.d_namlen = de->td_namelen;
  814                 MPASS(de->td_namelen < sizeof(d.d_name));
  815                 (void)memcpy(d.d_name, de->td_name, de->td_namelen);
  816                 d.d_name[de->td_namelen] = '\0';
  817                 d.d_reclen = GENERIC_DIRSIZ(&d);
  818 
  819                 /* Stop reading if the directory entry we are treating is
  820                  * bigger than the amount of data that can be returned. */
  821                 if (d.d_reclen > uio->uio_resid) {
  822                         error = -1;
  823                         break;
  824                 }
  825 
  826                 /* Copy the new dirent structure into the output buffer and
  827                  * advance pointers. */
  828                 error = uiomove(&d, d.d_reclen, uio);
  829                 if (error == 0) {
  830                         (*cntp)++;
  831                         de = TAILQ_NEXT(de, td_entries);
  832                 }
  833         } while (error == 0 && uio->uio_resid > 0 && de != NULL);
  834 
  835         /* Update the offset and cache. */
  836         if (de == NULL) {
  837                 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
  838                 node->tn_dir.tn_readdir_lastn = 0;
  839                 node->tn_dir.tn_readdir_lastp = NULL;
  840         } else {
  841                 node->tn_dir.tn_readdir_lastn = uio->uio_offset = tmpfs_dircookie(de);
  842                 node->tn_dir.tn_readdir_lastp = de;
  843         }
  844 
  845         node->tn_status |= TMPFS_NODE_ACCESSED;
  846         return error;
  847 }
  848 
  849 int
  850 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp)
  851 {
  852         struct tmpfs_dirent *de;
  853         int error;
  854 
  855         error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL,
  856             cnp->cn_nameptr, cnp->cn_namelen, &de);
  857         if (error != 0)
  858                 return (error);
  859         tmpfs_dir_attach(dvp, de);
  860         return (0);
  861 }
  862 
  863 void
  864 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp)
  865 {
  866         struct tmpfs_dirent *de;
  867 
  868         de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
  869         MPASS(de != NULL && de->td_node == NULL);
  870         tmpfs_dir_detach(dvp, de);
  871         tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de, TRUE);
  872 }
  873 
  874 /* --------------------------------------------------------------------- */
  875 
  876 /*
  877  * Resizes the aobj associated with the regular file pointed to by 'vp' to the
  878  * size 'newsize'.  'vp' must point to a vnode that represents a regular file.
  879  * 'newsize' must be positive.
  880  *
  881  * Returns zero on success or an appropriate error code on failure.
  882  */
  883 int
  884 tmpfs_reg_resize(struct vnode *vp, off_t newsize)
  885 {
  886         struct tmpfs_mount *tmp;
  887         struct tmpfs_node *node;
  888         vm_object_t uobj;
  889         vm_page_t m;
  890         vm_pindex_t newpages, oldpages;
  891         off_t oldsize;
  892         size_t zerolen;
  893 
  894         MPASS(vp->v_type == VREG);
  895         MPASS(newsize >= 0);
  896 
  897         node = VP_TO_TMPFS_NODE(vp);
  898         uobj = node->tn_reg.tn_aobj;
  899         tmp = VFS_TO_TMPFS(vp->v_mount);
  900 
  901         /*
  902          * Convert the old and new sizes to the number of pages needed to
  903          * store them.  It may happen that we do not need to do anything
  904          * because the last allocated page can accommodate the change on
  905          * its own.
  906          */
  907         oldsize = node->tn_size;
  908         oldpages = OFF_TO_IDX(oldsize + PAGE_MASK);
  909         MPASS(oldpages == uobj->size);
  910         newpages = OFF_TO_IDX(newsize + PAGE_MASK);
  911         if (newpages > oldpages &&
  912             newpages - oldpages > TMPFS_PAGES_AVAIL(tmp))
  913                 return (ENOSPC);
  914 
  915         TMPFS_LOCK(tmp);
  916         tmp->tm_pages_used += (newpages - oldpages);
  917         TMPFS_UNLOCK(tmp);
  918 
  919         node->tn_size = newsize;
  920         vnode_pager_setsize(vp, newsize);
  921         VM_OBJECT_LOCK(uobj);
  922         if (newsize < oldsize) {
  923                 /*
  924                  * Release any swap space and free any whole pages.
  925                  */
  926                 if (newpages < oldpages) {
  927                         swap_pager_freespace(uobj, newpages, oldpages -
  928                             newpages);
  929                         vm_object_page_remove(uobj, newpages, 0, 0);
  930                 }
  931 
  932                 /*
  933                  * Zero the truncated part of the last page.
  934                  */
  935                 zerolen = round_page(newsize) - newsize;
  936                 if (zerolen > 0) {
  937                         m = vm_page_grab(uobj, OFF_TO_IDX(newsize),
  938                             VM_ALLOC_NOBUSY | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
  939                         pmap_zero_page_area(m, PAGE_SIZE - zerolen, zerolen);
  940                 }
  941         }
  942         uobj->size = newpages;
  943         VM_OBJECT_UNLOCK(uobj);
  944         return (0);
  945 }
  946 
  947 /* --------------------------------------------------------------------- */
  948 
  949 /*
  950  * Change flags of the given vnode.
  951  * Caller should execute tmpfs_update on vp after a successful execution.
  952  * The vnode must be locked on entry and remain locked on exit.
  953  */
  954 int
  955 tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct thread *p)
  956 {
  957         int error;
  958         struct tmpfs_node *node;
  959 
  960         MPASS(VOP_ISLOCKED(vp));
  961 
  962         node = VP_TO_TMPFS_NODE(vp);
  963 
  964         /* Disallow this operation if the file system is mounted read-only. */
  965         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  966                 return EROFS;
  967 
  968         /*
  969          * Callers may only modify the file flags on objects they
  970          * have VADMIN rights for.
  971          */
  972         if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
  973                 return (error);
  974         /*
  975          * Unprivileged processes are not permitted to unset system
  976          * flags, or modify flags if any system flags are set.
  977          */
  978         if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
  979                 if (node->tn_flags
  980                   & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
  981                         error = securelevel_gt(cred, 0);
  982                         if (error)
  983                                 return (error);
  984                 }
  985                 /* Snapshot flag cannot be set or cleared */
  986                 if (((flags & SF_SNAPSHOT) != 0 &&
  987                   (node->tn_flags & SF_SNAPSHOT) == 0) ||
  988                   ((flags & SF_SNAPSHOT) == 0 &&
  989                   (node->tn_flags & SF_SNAPSHOT) != 0))
  990                         return (EPERM);
  991                 node->tn_flags = flags;
  992         } else {
  993                 if (node->tn_flags
  994                   & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
  995                   (flags & UF_SETTABLE) != flags)
  996                         return (EPERM);
  997                 node->tn_flags &= SF_SETTABLE;
  998                 node->tn_flags |= (flags & UF_SETTABLE);
  999         }
 1000         node->tn_status |= TMPFS_NODE_CHANGED;
 1001 
 1002         MPASS(VOP_ISLOCKED(vp));
 1003 
 1004         return 0;
 1005 }
 1006 
 1007 /* --------------------------------------------------------------------- */
 1008 
 1009 /*
 1010  * Change access mode on the given vnode.
 1011  * Caller should execute tmpfs_update on vp after a successful execution.
 1012  * The vnode must be locked on entry and remain locked on exit.
 1013  */
 1014 int
 1015 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p)
 1016 {
 1017         int error;
 1018         struct tmpfs_node *node;
 1019 
 1020         MPASS(VOP_ISLOCKED(vp));
 1021 
 1022         node = VP_TO_TMPFS_NODE(vp);
 1023 
 1024         /* Disallow this operation if the file system is mounted read-only. */
 1025         if (vp->v_mount->mnt_flag & MNT_RDONLY)
 1026                 return EROFS;
 1027 
 1028         /* Immutable or append-only files cannot be modified, either. */
 1029         if (node->tn_flags & (IMMUTABLE | APPEND))
 1030                 return EPERM;
 1031 
 1032         /*
 1033          * To modify the permissions on a file, must possess VADMIN
 1034          * for that file.
 1035          */
 1036         if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
 1037                 return (error);
 1038 
 1039         /*
 1040          * Privileged processes may set the sticky bit on non-directories,
 1041          * as well as set the setgid bit on a file with a group that the
 1042          * process is not a member of.
 1043          */
 1044         if (vp->v_type != VDIR && (mode & S_ISTXT)) {
 1045                 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0))
 1046                         return (EFTYPE);
 1047         }
 1048         if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) {
 1049                 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
 1050                 if (error)
 1051                         return (error);
 1052         }
 1053 
 1054 
 1055         node->tn_mode &= ~ALLPERMS;
 1056         node->tn_mode |= mode & ALLPERMS;
 1057 
 1058         node->tn_status |= TMPFS_NODE_CHANGED;
 1059 
 1060         MPASS(VOP_ISLOCKED(vp));
 1061 
 1062         return 0;
 1063 }
 1064 
 1065 /* --------------------------------------------------------------------- */
 1066 
 1067 /*
 1068  * Change ownership of the given vnode.  At least one of uid or gid must
 1069  * be different than VNOVAL.  If one is set to that value, the attribute
 1070  * is unchanged.
 1071  * Caller should execute tmpfs_update on vp after a successful execution.
 1072  * The vnode must be locked on entry and remain locked on exit.
 1073  */
 1074 int
 1075 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
 1076     struct thread *p)
 1077 {
 1078         int error;
 1079         struct tmpfs_node *node;
 1080         uid_t ouid;
 1081         gid_t ogid;
 1082 
 1083         MPASS(VOP_ISLOCKED(vp));
 1084 
 1085         node = VP_TO_TMPFS_NODE(vp);
 1086 
 1087         /* Assign default values if they are unknown. */
 1088         MPASS(uid != VNOVAL || gid != VNOVAL);
 1089         if (uid == VNOVAL)
 1090                 uid = node->tn_uid;
 1091         if (gid == VNOVAL)
 1092                 gid = node->tn_gid;
 1093         MPASS(uid != VNOVAL && gid != VNOVAL);
 1094 
 1095         /* Disallow this operation if the file system is mounted read-only. */
 1096         if (vp->v_mount->mnt_flag & MNT_RDONLY)
 1097                 return EROFS;
 1098 
 1099         /* Immutable or append-only files cannot be modified, either. */
 1100         if (node->tn_flags & (IMMUTABLE | APPEND))
 1101                 return EPERM;
 1102 
 1103         /*
 1104          * To modify the ownership of a file, must possess VADMIN for that
 1105          * file.
 1106          */
 1107         if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
 1108                 return (error);
 1109 
 1110         /*
 1111          * To change the owner of a file, or change the group of a file to a
 1112          * group of which we are not a member, the caller must have
 1113          * privilege.
 1114          */
 1115         if ((uid != node->tn_uid ||
 1116             (gid != node->tn_gid && !groupmember(gid, cred))) &&
 1117             (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
 1118                 return (error);
 1119 
 1120         ogid = node->tn_gid;
 1121         ouid = node->tn_uid;
 1122 
 1123         node->tn_uid = uid;
 1124         node->tn_gid = gid;
 1125 
 1126         node->tn_status |= TMPFS_NODE_CHANGED;
 1127 
 1128         if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) {
 1129                 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0))
 1130                         node->tn_mode &= ~(S_ISUID | S_ISGID);
 1131         }
 1132 
 1133         MPASS(VOP_ISLOCKED(vp));
 1134 
 1135         return 0;
 1136 }
 1137 
 1138 /* --------------------------------------------------------------------- */
 1139 
 1140 /*
 1141  * Change size of the given vnode.
 1142  * Caller should execute tmpfs_update on vp after a successful execution.
 1143  * The vnode must be locked on entry and remain locked on exit.
 1144  */
 1145 int
 1146 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred,
 1147     struct thread *p)
 1148 {
 1149         int error;
 1150         struct tmpfs_node *node;
 1151 
 1152         MPASS(VOP_ISLOCKED(vp));
 1153 
 1154         node = VP_TO_TMPFS_NODE(vp);
 1155 
 1156         /* Decide whether this is a valid operation based on the file type. */
 1157         error = 0;
 1158         switch (vp->v_type) {
 1159         case VDIR:
 1160                 return EISDIR;
 1161 
 1162         case VREG:
 1163                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
 1164                         return EROFS;
 1165                 break;
 1166 
 1167         case VBLK:
 1168                 /* FALLTHROUGH */
 1169         case VCHR:
 1170                 /* FALLTHROUGH */
 1171         case VFIFO:
 1172                 /* Allow modifications of special files even if in the file
 1173                  * system is mounted read-only (we are not modifying the
 1174                  * files themselves, but the objects they represent). */
 1175                 return 0;
 1176 
 1177         default:
 1178                 /* Anything else is unsupported. */
 1179                 return EOPNOTSUPP;
 1180         }
 1181 
 1182         /* Immutable or append-only files cannot be modified, either. */
 1183         if (node->tn_flags & (IMMUTABLE | APPEND))
 1184                 return EPERM;
 1185 
 1186         error = tmpfs_truncate(vp, size);
 1187         /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
 1188          * for us, as will update tn_status; no need to do that here. */
 1189 
 1190         MPASS(VOP_ISLOCKED(vp));
 1191 
 1192         return error;
 1193 }
 1194 
 1195 /* --------------------------------------------------------------------- */
 1196 
 1197 /*
 1198  * Change access and modification times of the given vnode.
 1199  * Caller should execute tmpfs_update on vp after a successful execution.
 1200  * The vnode must be locked on entry and remain locked on exit.
 1201  */
 1202 int
 1203 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
 1204         struct timespec *birthtime, int vaflags, struct ucred *cred, struct thread *l)
 1205 {
 1206         int error;
 1207         struct tmpfs_node *node;
 1208 
 1209         MPASS(VOP_ISLOCKED(vp));
 1210 
 1211         node = VP_TO_TMPFS_NODE(vp);
 1212 
 1213         /* Disallow this operation if the file system is mounted read-only. */
 1214         if (vp->v_mount->mnt_flag & MNT_RDONLY)
 1215                 return EROFS;
 1216 
 1217         /* Immutable or append-only files cannot be modified, either. */
 1218         if (node->tn_flags & (IMMUTABLE | APPEND))
 1219                 return EPERM;
 1220 
 1221         /* Determine if the user have proper privilege to update time. */
 1222         if (vaflags & VA_UTIMES_NULL) {
 1223                 error = VOP_ACCESS(vp, VADMIN, cred, l);
 1224                 if (error)
 1225                         error = VOP_ACCESS(vp, VWRITE, cred, l);
 1226         } else
 1227                 error = VOP_ACCESS(vp, VADMIN, cred, l);
 1228         if (error)
 1229                 return (error);
 1230 
 1231         if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
 1232                 node->tn_status |= TMPFS_NODE_ACCESSED;
 1233 
 1234         if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL)
 1235                 node->tn_status |= TMPFS_NODE_MODIFIED;
 1236 
 1237         if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL)
 1238                 node->tn_status |= TMPFS_NODE_MODIFIED;
 1239 
 1240         tmpfs_itimes(vp, atime, mtime);
 1241 
 1242         if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL)
 1243                 node->tn_birthtime = *birthtime;
 1244         MPASS(VOP_ISLOCKED(vp));
 1245 
 1246         return 0;
 1247 }
 1248 
 1249 /* --------------------------------------------------------------------- */
 1250 /* Sync timestamps */
 1251 void
 1252 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
 1253     const struct timespec *mod)
 1254 {
 1255         struct tmpfs_node *node;
 1256         struct timespec now;
 1257 
 1258         node = VP_TO_TMPFS_NODE(vp);
 1259 
 1260         if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
 1261             TMPFS_NODE_CHANGED)) == 0)
 1262                 return;
 1263 
 1264         vfs_timestamp(&now);
 1265         if (node->tn_status & TMPFS_NODE_ACCESSED) {
 1266                 if (acc == NULL)
 1267                          acc = &now;
 1268                 node->tn_atime = *acc;
 1269         }
 1270         if (node->tn_status & TMPFS_NODE_MODIFIED) {
 1271                 if (mod == NULL)
 1272                         mod = &now;
 1273                 node->tn_mtime = *mod;
 1274         }
 1275         if (node->tn_status & TMPFS_NODE_CHANGED) {
 1276                 node->tn_ctime = now;
 1277         }
 1278         node->tn_status &=
 1279             ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED);
 1280 }
 1281 
 1282 /* --------------------------------------------------------------------- */
 1283 
 1284 void
 1285 tmpfs_update(struct vnode *vp)
 1286 {
 1287 
 1288         tmpfs_itimes(vp, NULL, NULL);
 1289 }
 1290 
 1291 /* --------------------------------------------------------------------- */
 1292 
 1293 int
 1294 tmpfs_truncate(struct vnode *vp, off_t length)
 1295 {
 1296         int error;
 1297         struct tmpfs_node *node;
 1298 
 1299         node = VP_TO_TMPFS_NODE(vp);
 1300 
 1301         if (length < 0) {
 1302                 error = EINVAL;
 1303                 goto out;
 1304         }
 1305 
 1306         if (node->tn_size == length) {
 1307                 error = 0;
 1308                 goto out;
 1309         }
 1310 
 1311         if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
 1312                 return (EFBIG);
 1313 
 1314         error = tmpfs_reg_resize(vp, length);
 1315         if (error == 0) {
 1316                 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
 1317         }
 1318 
 1319 out:
 1320         tmpfs_update(vp);
 1321 
 1322         return error;
 1323 }
Cache object: 4c697778a7bafac04c2ea4bff29229dd
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FreeBSD/Linux Kernel Cross Reference sys/fs/tmpfs/tmpfs_subr.c

FreeBSD/Linux Kernel Cross Reference
sys/fs/tmpfs/tmpfs_subr.c
