The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_default.c

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    1 /*-
    2  * Copyright (c) 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * This code is derived from software contributed
    6  * to Berkeley by John Heidemann of the UCLA Ficus project.
    7  *
    8  * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD: releng/9.0/sys/kern/vfs_default.c 222167 2011-05-22 01:07:54Z rmacklem $");
   37 
   38 #include <sys/param.h>
   39 #include <sys/systm.h>
   40 #include <sys/bio.h>
   41 #include <sys/buf.h>
   42 #include <sys/conf.h>
   43 #include <sys/event.h>
   44 #include <sys/kernel.h>
   45 #include <sys/limits.h>
   46 #include <sys/lock.h>
   47 #include <sys/lockf.h>
   48 #include <sys/malloc.h>
   49 #include <sys/mount.h>
   50 #include <sys/mutex.h>
   51 #include <sys/namei.h>
   52 #include <sys/fcntl.h>
   53 #include <sys/unistd.h>
   54 #include <sys/vnode.h>
   55 #include <sys/dirent.h>
   56 #include <sys/poll.h>
   57 
   58 #include <security/mac/mac_framework.h>
   59 
   60 #include <vm/vm.h>
   61 #include <vm/vm_object.h>
   62 #include <vm/vm_extern.h>
   63 #include <vm/pmap.h>
   64 #include <vm/vm_map.h>
   65 #include <vm/vm_page.h>
   66 #include <vm/vm_pager.h>
   67 #include <vm/vnode_pager.h>
   68 
   69 static int      vop_nolookup(struct vop_lookup_args *);
   70 static int      vop_norename(struct vop_rename_args *);
   71 static int      vop_nostrategy(struct vop_strategy_args *);
   72 static int      get_next_dirent(struct vnode *vp, struct dirent **dpp,
   73                                 char *dirbuf, int dirbuflen, off_t *off,
   74                                 char **cpos, int *len, int *eofflag,
   75                                 struct thread *td);
   76 static int      dirent_exists(struct vnode *vp, const char *dirname,
   77                               struct thread *td);
   78 
   79 #define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4)
   80 
   81 /*
   82  * This vnode table stores what we want to do if the filesystem doesn't
   83  * implement a particular VOP.
   84  *
   85  * If there is no specific entry here, we will return EOPNOTSUPP.
   86  *
   87  * Note that every filesystem has to implement either vop_access
   88  * or vop_accessx; failing to do so will result in immediate crash
   89  * due to stack overflow, as vop_stdaccess() calls vop_stdaccessx(),
   90  * which calls vop_stdaccess() etc.
   91  */
   92 
   93 struct vop_vector default_vnodeops = {
   94         .vop_default =          NULL,
   95         .vop_bypass =           VOP_EOPNOTSUPP,
   96 
   97         .vop_access =           vop_stdaccess,
   98         .vop_accessx =          vop_stdaccessx,
   99         .vop_advlock =          vop_stdadvlock,
  100         .vop_advlockasync =     vop_stdadvlockasync,
  101         .vop_advlockpurge =     vop_stdadvlockpurge,
  102         .vop_allocate =         vop_stdallocate,
  103         .vop_bmap =             vop_stdbmap,
  104         .vop_close =            VOP_NULL,
  105         .vop_fsync =            VOP_NULL,
  106         .vop_getpages =         vop_stdgetpages,
  107         .vop_getwritemount =    vop_stdgetwritemount,
  108         .vop_inactive =         VOP_NULL,
  109         .vop_ioctl =            VOP_ENOTTY,
  110         .vop_kqfilter =         vop_stdkqfilter,
  111         .vop_islocked =         vop_stdislocked,
  112         .vop_lock1 =            vop_stdlock,
  113         .vop_lookup =           vop_nolookup,
  114         .vop_open =             VOP_NULL,
  115         .vop_pathconf =         VOP_EINVAL,
  116         .vop_poll =             vop_nopoll,
  117         .vop_putpages =         vop_stdputpages,
  118         .vop_readlink =         VOP_EINVAL,
  119         .vop_rename =           vop_norename,
  120         .vop_revoke =           VOP_PANIC,
  121         .vop_strategy =         vop_nostrategy,
  122         .vop_unlock =           vop_stdunlock,
  123         .vop_vptocnp =          vop_stdvptocnp,
  124         .vop_vptofh =           vop_stdvptofh,
  125 };
  126 
  127 /*
  128  * Series of placeholder functions for various error returns for
  129  * VOPs.
  130  */
  131 
  132 int
  133 vop_eopnotsupp(struct vop_generic_args *ap)
  134 {
  135         /*
  136         printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name);
  137         */
  138 
  139         return (EOPNOTSUPP);
  140 }
  141 
  142 int
  143 vop_ebadf(struct vop_generic_args *ap)
  144 {
  145 
  146         return (EBADF);
  147 }
  148 
  149 int
  150 vop_enotty(struct vop_generic_args *ap)
  151 {
  152 
  153         return (ENOTTY);
  154 }
  155 
  156 int
  157 vop_einval(struct vop_generic_args *ap)
  158 {
  159 
  160         return (EINVAL);
  161 }
  162 
  163 int
  164 vop_enoent(struct vop_generic_args *ap)
  165 {
  166 
  167         return (ENOENT);
  168 }
  169 
  170 int
  171 vop_null(struct vop_generic_args *ap)
  172 {
  173 
  174         return (0);
  175 }
  176 
  177 /*
  178  * Helper function to panic on some bad VOPs in some filesystems.
  179  */
  180 int
  181 vop_panic(struct vop_generic_args *ap)
  182 {
  183 
  184         panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name);
  185 }
  186 
  187 /*
  188  * vop_std<something> and vop_no<something> are default functions for use by
  189  * filesystems that need the "default reasonable" implementation for a
  190  * particular operation.
  191  *
  192  * The documentation for the operations they implement exists (if it exists)
  193  * in the VOP_<SOMETHING>(9) manpage (all uppercase).
  194  */
  195 
  196 /*
  197  * Default vop for filesystems that do not support name lookup
  198  */
  199 static int
  200 vop_nolookup(ap)
  201         struct vop_lookup_args /* {
  202                 struct vnode *a_dvp;
  203                 struct vnode **a_vpp;
  204                 struct componentname *a_cnp;
  205         } */ *ap;
  206 {
  207 
  208         *ap->a_vpp = NULL;
  209         return (ENOTDIR);
  210 }
  211 
  212 /*
  213  * vop_norename:
  214  *
  215  * Handle unlock and reference counting for arguments of vop_rename
  216  * for filesystems that do not implement rename operation.
  217  */
  218 static int
  219 vop_norename(struct vop_rename_args *ap)
  220 {
  221 
  222         vop_rename_fail(ap);
  223         return (EOPNOTSUPP);
  224 }
  225 
  226 /*
  227  *      vop_nostrategy:
  228  *
  229  *      Strategy routine for VFS devices that have none.
  230  *
  231  *      BIO_ERROR and B_INVAL must be cleared prior to calling any strategy
  232  *      routine.  Typically this is done for a BIO_READ strategy call.
  233  *      Typically B_INVAL is assumed to already be clear prior to a write
  234  *      and should not be cleared manually unless you just made the buffer
  235  *      invalid.  BIO_ERROR should be cleared either way.
  236  */
  237 
  238 static int
  239 vop_nostrategy (struct vop_strategy_args *ap)
  240 {
  241         printf("No strategy for buffer at %p\n", ap->a_bp);
  242         vprint("vnode", ap->a_vp);
  243         ap->a_bp->b_ioflags |= BIO_ERROR;
  244         ap->a_bp->b_error = EOPNOTSUPP;
  245         bufdone(ap->a_bp);
  246         return (EOPNOTSUPP);
  247 }
  248 
  249 static int
  250 get_next_dirent(struct vnode *vp, struct dirent **dpp, char *dirbuf,
  251                 int dirbuflen, off_t *off, char **cpos, int *len,
  252                 int *eofflag, struct thread *td)
  253 {
  254         int error, reclen;
  255         struct uio uio;
  256         struct iovec iov;
  257         struct dirent *dp;
  258 
  259         KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
  260         KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
  261 
  262         if (*len == 0) {
  263                 iov.iov_base = dirbuf;
  264                 iov.iov_len = dirbuflen;
  265 
  266                 uio.uio_iov = &iov;
  267                 uio.uio_iovcnt = 1;
  268                 uio.uio_offset = *off;
  269                 uio.uio_resid = dirbuflen;
  270                 uio.uio_segflg = UIO_SYSSPACE;
  271                 uio.uio_rw = UIO_READ;
  272                 uio.uio_td = td;
  273 
  274                 *eofflag = 0;
  275 
  276 #ifdef MAC
  277                 error = mac_vnode_check_readdir(td->td_ucred, vp);
  278                 if (error == 0)
  279 #endif
  280                         error = VOP_READDIR(vp, &uio, td->td_ucred, eofflag,
  281                                 NULL, NULL);
  282                 if (error)
  283                         return (error);
  284 
  285                 *off = uio.uio_offset;
  286 
  287                 *cpos = dirbuf;
  288                 *len = (dirbuflen - uio.uio_resid);
  289 
  290                 if (*len == 0)
  291                         return (ENOENT);
  292         }
  293 
  294         dp = (struct dirent *)(*cpos);
  295         reclen = dp->d_reclen;
  296         *dpp = dp;
  297 
  298         /* check for malformed directory.. */
  299         if (reclen < DIRENT_MINSIZE)
  300                 return (EINVAL);
  301 
  302         *cpos += reclen;
  303         *len -= reclen;
  304 
  305         return (0);
  306 }
  307 
  308 /*
  309  * Check if a named file exists in a given directory vnode.
  310  */
  311 static int
  312 dirent_exists(struct vnode *vp, const char *dirname, struct thread *td)
  313 {
  314         char *dirbuf, *cpos;
  315         int error, eofflag, dirbuflen, len, found;
  316         off_t off;
  317         struct dirent *dp;
  318         struct vattr va;
  319 
  320         KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
  321         KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
  322 
  323         found = 0;
  324 
  325         error = VOP_GETATTR(vp, &va, td->td_ucred);
  326         if (error)
  327                 return (found);
  328 
  329         dirbuflen = DEV_BSIZE;
  330         if (dirbuflen < va.va_blocksize)
  331                 dirbuflen = va.va_blocksize;
  332         dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
  333 
  334         off = 0;
  335         len = 0;
  336         do {
  337                 error = get_next_dirent(vp, &dp, dirbuf, dirbuflen, &off,
  338                                         &cpos, &len, &eofflag, td);
  339                 if (error)
  340                         goto out;
  341 
  342                 if ((dp->d_type != DT_WHT) &&
  343                     !strcmp(dp->d_name, dirname)) {
  344                         found = 1;
  345                         goto out;
  346                 }
  347         } while (len > 0 || !eofflag);
  348 
  349 out:
  350         free(dirbuf, M_TEMP);
  351         return (found);
  352 }
  353 
  354 int
  355 vop_stdaccess(struct vop_access_args *ap)
  356 {
  357 
  358         KASSERT((ap->a_accmode & ~(VEXEC | VWRITE | VREAD | VADMIN |
  359             VAPPEND)) == 0, ("invalid bit in accmode"));
  360 
  361         return (VOP_ACCESSX(ap->a_vp, ap->a_accmode, ap->a_cred, ap->a_td));
  362 }
  363 
  364 int
  365 vop_stdaccessx(struct vop_accessx_args *ap)
  366 {
  367         int error;
  368         accmode_t accmode = ap->a_accmode;
  369 
  370         error = vfs_unixify_accmode(&accmode);
  371         if (error != 0)
  372                 return (error);
  373 
  374         if (accmode == 0)
  375                 return (0);
  376 
  377         return (VOP_ACCESS(ap->a_vp, accmode, ap->a_cred, ap->a_td));
  378 }
  379 
  380 /*
  381  * Advisory record locking support
  382  */
  383 int
  384 vop_stdadvlock(struct vop_advlock_args *ap)
  385 {
  386         struct vnode *vp;
  387         struct ucred *cred;
  388         struct vattr vattr;
  389         int error;
  390 
  391         vp = ap->a_vp;
  392         cred = curthread->td_ucred;
  393         vn_lock(vp, LK_SHARED | LK_RETRY);
  394         error = VOP_GETATTR(vp, &vattr, cred);
  395         VOP_UNLOCK(vp, 0);
  396         if (error)
  397                 return (error);
  398 
  399         return (lf_advlock(ap, &(vp->v_lockf), vattr.va_size));
  400 }
  401 
  402 int
  403 vop_stdadvlockasync(struct vop_advlockasync_args *ap)
  404 {
  405         struct vnode *vp;
  406         struct ucred *cred;
  407         struct vattr vattr;
  408         int error;
  409 
  410         vp = ap->a_vp;
  411         cred = curthread->td_ucred;
  412         vn_lock(vp, LK_SHARED | LK_RETRY);
  413         error = VOP_GETATTR(vp, &vattr, cred);
  414         VOP_UNLOCK(vp, 0);
  415         if (error)
  416                 return (error);
  417 
  418         return (lf_advlockasync(ap, &(vp->v_lockf), vattr.va_size));
  419 }
  420 
  421 int
  422 vop_stdadvlockpurge(struct vop_advlockpurge_args *ap)
  423 {
  424         struct vnode *vp;
  425 
  426         vp = ap->a_vp;
  427         lf_purgelocks(vp, &vp->v_lockf);
  428         return (0);
  429 }
  430 
  431 /*
  432  * vop_stdpathconf:
  433  *
  434  * Standard implementation of POSIX pathconf, to get information about limits
  435  * for a filesystem.
  436  * Override per filesystem for the case where the filesystem has smaller
  437  * limits.
  438  */
  439 int
  440 vop_stdpathconf(ap)
  441         struct vop_pathconf_args /* {
  442         struct vnode *a_vp;
  443         int a_name;
  444         int *a_retval;
  445         } */ *ap;
  446 {
  447 
  448         switch (ap->a_name) {
  449                 case _PC_NAME_MAX:
  450                         *ap->a_retval = NAME_MAX;
  451                         return (0);
  452                 case _PC_PATH_MAX:
  453                         *ap->a_retval = PATH_MAX;
  454                         return (0);
  455                 case _PC_LINK_MAX:
  456                         *ap->a_retval = LINK_MAX;
  457                         return (0);
  458                 case _PC_MAX_CANON:
  459                         *ap->a_retval = MAX_CANON;
  460                         return (0);
  461                 case _PC_MAX_INPUT:
  462                         *ap->a_retval = MAX_INPUT;
  463                         return (0);
  464                 case _PC_PIPE_BUF:
  465                         *ap->a_retval = PIPE_BUF;
  466                         return (0);
  467                 case _PC_CHOWN_RESTRICTED:
  468                         *ap->a_retval = 1;
  469                         return (0);
  470                 case _PC_VDISABLE:
  471                         *ap->a_retval = _POSIX_VDISABLE;
  472                         return (0);
  473                 default:
  474                         return (EINVAL);
  475         }
  476         /* NOTREACHED */
  477 }
  478 
  479 /*
  480  * Standard lock, unlock and islocked functions.
  481  */
  482 int
  483 vop_stdlock(ap)
  484         struct vop_lock1_args /* {
  485                 struct vnode *a_vp;
  486                 int a_flags;
  487                 char *file;
  488                 int line;
  489         } */ *ap;
  490 {
  491         struct vnode *vp = ap->a_vp;
  492 
  493         return (_lockmgr_args(vp->v_vnlock, ap->a_flags, VI_MTX(vp),
  494             LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, ap->a_file,
  495             ap->a_line));
  496 }
  497 
  498 /* See above. */
  499 int
  500 vop_stdunlock(ap)
  501         struct vop_unlock_args /* {
  502                 struct vnode *a_vp;
  503                 int a_flags;
  504         } */ *ap;
  505 {
  506         struct vnode *vp = ap->a_vp;
  507 
  508         return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp)));
  509 }
  510 
  511 /* See above. */
  512 int
  513 vop_stdislocked(ap)
  514         struct vop_islocked_args /* {
  515                 struct vnode *a_vp;
  516         } */ *ap;
  517 {
  518 
  519         return (lockstatus(ap->a_vp->v_vnlock));
  520 }
  521 
  522 /*
  523  * Return true for select/poll.
  524  */
  525 int
  526 vop_nopoll(ap)
  527         struct vop_poll_args /* {
  528                 struct vnode *a_vp;
  529                 int  a_events;
  530                 struct ucred *a_cred;
  531                 struct thread *a_td;
  532         } */ *ap;
  533 {
  534 
  535         return (poll_no_poll(ap->a_events));
  536 }
  537 
  538 /*
  539  * Implement poll for local filesystems that support it.
  540  */
  541 int
  542 vop_stdpoll(ap)
  543         struct vop_poll_args /* {
  544                 struct vnode *a_vp;
  545                 int  a_events;
  546                 struct ucred *a_cred;
  547                 struct thread *a_td;
  548         } */ *ap;
  549 {
  550         if (ap->a_events & ~POLLSTANDARD)
  551                 return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events));
  552         return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
  553 }
  554 
  555 /*
  556  * Return our mount point, as we will take charge of the writes.
  557  */
  558 int
  559 vop_stdgetwritemount(ap)
  560         struct vop_getwritemount_args /* {
  561                 struct vnode *a_vp;
  562                 struct mount **a_mpp;
  563         } */ *ap;
  564 {
  565         struct mount *mp;
  566 
  567         /*
  568          * XXX Since this is called unlocked we may be recycled while
  569          * attempting to ref the mount.  If this is the case or mountpoint
  570          * will be set to NULL.  We only have to prevent this call from
  571          * returning with a ref to an incorrect mountpoint.  It is not
  572          * harmful to return with a ref to our previous mountpoint.
  573          */
  574         mp = ap->a_vp->v_mount;
  575         if (mp != NULL) {
  576                 vfs_ref(mp);
  577                 if (mp != ap->a_vp->v_mount) {
  578                         vfs_rel(mp);
  579                         mp = NULL;
  580                 }
  581         }
  582         *(ap->a_mpp) = mp;
  583         return (0);
  584 }
  585 
  586 /* XXX Needs good comment and VOP_BMAP(9) manpage */
  587 int
  588 vop_stdbmap(ap)
  589         struct vop_bmap_args /* {
  590                 struct vnode *a_vp;
  591                 daddr_t  a_bn;
  592                 struct bufobj **a_bop;
  593                 daddr_t *a_bnp;
  594                 int *a_runp;
  595                 int *a_runb;
  596         } */ *ap;
  597 {
  598 
  599         if (ap->a_bop != NULL)
  600                 *ap->a_bop = &ap->a_vp->v_bufobj;
  601         if (ap->a_bnp != NULL)
  602                 *ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize);
  603         if (ap->a_runp != NULL)
  604                 *ap->a_runp = 0;
  605         if (ap->a_runb != NULL)
  606                 *ap->a_runb = 0;
  607         return (0);
  608 }
  609 
  610 int
  611 vop_stdfsync(ap)
  612         struct vop_fsync_args /* {
  613                 struct vnode *a_vp;
  614                 struct ucred *a_cred;
  615                 int a_waitfor;
  616                 struct thread *a_td;
  617         } */ *ap;
  618 {
  619         struct vnode *vp = ap->a_vp;
  620         struct buf *bp;
  621         struct bufobj *bo;
  622         struct buf *nbp;
  623         int error = 0;
  624         int maxretry = 1000;     /* large, arbitrarily chosen */
  625 
  626         bo = &vp->v_bufobj;
  627         BO_LOCK(bo);
  628 loop1:
  629         /*
  630          * MARK/SCAN initialization to avoid infinite loops.
  631          */
  632         TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
  633                 bp->b_vflags &= ~BV_SCANNED;
  634                 bp->b_error = 0;
  635         }
  636 
  637         /*
  638          * Flush all dirty buffers associated with a vnode.
  639          */
  640 loop2:
  641         TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
  642                 if ((bp->b_vflags & BV_SCANNED) != 0)
  643                         continue;
  644                 bp->b_vflags |= BV_SCANNED;
  645                 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL))
  646                         continue;
  647                 BO_UNLOCK(bo);
  648                 KASSERT(bp->b_bufobj == bo,
  649                     ("bp %p wrong b_bufobj %p should be %p",
  650                     bp, bp->b_bufobj, bo));
  651                 if ((bp->b_flags & B_DELWRI) == 0)
  652                         panic("fsync: not dirty");
  653                 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
  654                         vfs_bio_awrite(bp);
  655                 } else {
  656                         bremfree(bp);
  657                         bawrite(bp);
  658                 }
  659                 BO_LOCK(bo);
  660                 goto loop2;
  661         }
  662 
  663         /*
  664          * If synchronous the caller expects us to completely resolve all
  665          * dirty buffers in the system.  Wait for in-progress I/O to
  666          * complete (which could include background bitmap writes), then
  667          * retry if dirty blocks still exist.
  668          */
  669         if (ap->a_waitfor == MNT_WAIT) {
  670                 bufobj_wwait(bo, 0, 0);
  671                 if (bo->bo_dirty.bv_cnt > 0) {
  672                         /*
  673                          * If we are unable to write any of these buffers
  674                          * then we fail now rather than trying endlessly
  675                          * to write them out.
  676                          */
  677                         TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
  678                                 if ((error = bp->b_error) == 0)
  679                                         continue;
  680                         if (error == 0 && --maxretry >= 0)
  681                                 goto loop1;
  682                         error = EAGAIN;
  683                 }
  684         }
  685         BO_UNLOCK(bo);
  686         if (error == EAGAIN)
  687                 vprint("fsync: giving up on dirty", vp);
  688 
  689         return (error);
  690 }
  691 
  692 /* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */
  693 int
  694 vop_stdgetpages(ap)
  695         struct vop_getpages_args /* {
  696                 struct vnode *a_vp;
  697                 vm_page_t *a_m;
  698                 int a_count;
  699                 int a_reqpage;
  700                 vm_ooffset_t a_offset;
  701         } */ *ap;
  702 {
  703 
  704         return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
  705             ap->a_count, ap->a_reqpage);
  706 }
  707 
  708 int
  709 vop_stdkqfilter(struct vop_kqfilter_args *ap)
  710 {
  711         return vfs_kqfilter(ap);
  712 }
  713 
  714 /* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */
  715 int
  716 vop_stdputpages(ap)
  717         struct vop_putpages_args /* {
  718                 struct vnode *a_vp;
  719                 vm_page_t *a_m;
  720                 int a_count;
  721                 int a_sync;
  722                 int *a_rtvals;
  723                 vm_ooffset_t a_offset;
  724         } */ *ap;
  725 {
  726 
  727         return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
  728              ap->a_sync, ap->a_rtvals);
  729 }
  730 
  731 int
  732 vop_stdvptofh(struct vop_vptofh_args *ap)
  733 {
  734         return (EOPNOTSUPP);
  735 }
  736 
  737 int
  738 vop_stdvptocnp(struct vop_vptocnp_args *ap)
  739 {
  740         struct vnode *vp = ap->a_vp;
  741         struct vnode **dvp = ap->a_vpp;
  742         struct ucred *cred = ap->a_cred;
  743         char *buf = ap->a_buf;
  744         int *buflen = ap->a_buflen;
  745         char *dirbuf, *cpos;
  746         int i, error, eofflag, dirbuflen, flags, locked, len, covered;
  747         off_t off;
  748         ino_t fileno;
  749         struct vattr va;
  750         struct nameidata nd;
  751         struct thread *td;
  752         struct dirent *dp;
  753         struct vnode *mvp;
  754 
  755         i = *buflen;
  756         error = 0;
  757         covered = 0;
  758         td = curthread;
  759 
  760         if (vp->v_type != VDIR)
  761                 return (ENOENT);
  762 
  763         error = VOP_GETATTR(vp, &va, cred);
  764         if (error)
  765                 return (error);
  766 
  767         VREF(vp);
  768         locked = VOP_ISLOCKED(vp);
  769         VOP_UNLOCK(vp, 0);
  770         NDINIT_ATVP(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
  771             "..", vp, td);
  772         flags = FREAD;
  773         error = vn_open_cred(&nd, &flags, 0, VN_OPEN_NOAUDIT, cred, NULL);
  774         if (error) {
  775                 vn_lock(vp, locked | LK_RETRY);
  776                 return (error);
  777         }
  778         NDFREE(&nd, NDF_ONLY_PNBUF);
  779 
  780         mvp = *dvp = nd.ni_vp;
  781 
  782         if (vp->v_mount != (*dvp)->v_mount &&
  783             ((*dvp)->v_vflag & VV_ROOT) &&
  784             ((*dvp)->v_mount->mnt_flag & MNT_UNION)) {
  785                 *dvp = (*dvp)->v_mount->mnt_vnodecovered;
  786                 VREF(mvp);
  787                 VOP_UNLOCK(mvp, 0);
  788                 vn_close(mvp, FREAD, cred, td);
  789                 VREF(*dvp);
  790                 vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  791                 covered = 1;
  792         }
  793 
  794         fileno = va.va_fileid;
  795 
  796         dirbuflen = DEV_BSIZE;
  797         if (dirbuflen < va.va_blocksize)
  798                 dirbuflen = va.va_blocksize;
  799         dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
  800 
  801         if ((*dvp)->v_type != VDIR) {
  802                 error = ENOENT;
  803                 goto out;
  804         }
  805 
  806         off = 0;
  807         len = 0;
  808         do {
  809                 /* call VOP_READDIR of parent */
  810                 error = get_next_dirent(*dvp, &dp, dirbuf, dirbuflen, &off,
  811                                         &cpos, &len, &eofflag, td);
  812                 if (error)
  813                         goto out;
  814 
  815                 if ((dp->d_type != DT_WHT) &&
  816                     (dp->d_fileno == fileno)) {
  817                         if (covered) {
  818                                 VOP_UNLOCK(*dvp, 0);
  819                                 vn_lock(mvp, LK_EXCLUSIVE | LK_RETRY);
  820                                 if (dirent_exists(mvp, dp->d_name, td)) {
  821                                         error = ENOENT;
  822                                         VOP_UNLOCK(mvp, 0);
  823                                         vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  824                                         goto out;
  825                                 }
  826                                 VOP_UNLOCK(mvp, 0);
  827                                 vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  828                         }
  829                         i -= dp->d_namlen;
  830 
  831                         if (i < 0) {
  832                                 error = ENOMEM;
  833                                 goto out;
  834                         }
  835                         bcopy(dp->d_name, buf + i, dp->d_namlen);
  836                         error = 0;
  837                         goto out;
  838                 }
  839         } while (len > 0 || !eofflag);
  840         error = ENOENT;
  841 
  842 out:
  843         free(dirbuf, M_TEMP);
  844         if (!error) {
  845                 *buflen = i;
  846                 vhold(*dvp);
  847         }
  848         if (covered) {
  849                 vput(*dvp);
  850                 vrele(mvp);
  851         } else {
  852                 VOP_UNLOCK(mvp, 0);
  853                 vn_close(mvp, FREAD, cred, td);
  854         }
  855         vn_lock(vp, locked | LK_RETRY);
  856         return (error);
  857 }
  858 
  859 int
  860 vop_stdallocate(struct vop_allocate_args *ap)
  861 {
  862 #ifdef __notyet__
  863         struct statfs sfs;
  864 #endif
  865         struct iovec aiov;
  866         struct vattr vattr, *vap;
  867         struct uio auio;
  868         off_t fsize, len, cur, offset;
  869         uint8_t *buf;
  870         struct thread *td;
  871         struct vnode *vp;
  872         size_t iosize;
  873         int error;
  874 
  875         buf = NULL;
  876         error = 0;
  877         td = curthread;
  878         vap = &vattr;
  879         vp = ap->a_vp;
  880         len = *ap->a_len;
  881         offset = *ap->a_offset;
  882 
  883         error = VOP_GETATTR(vp, vap, td->td_ucred);
  884         if (error != 0)
  885                 goto out;
  886         fsize = vap->va_size;
  887         iosize = vap->va_blocksize;
  888         if (iosize == 0)
  889                 iosize = BLKDEV_IOSIZE;
  890         if (iosize > MAXPHYS)
  891                 iosize = MAXPHYS;
  892         buf = malloc(iosize, M_TEMP, M_WAITOK);
  893 
  894 #ifdef __notyet__
  895         /*
  896          * Check if the filesystem sets f_maxfilesize; if not use
  897          * VOP_SETATTR to perform the check.
  898          */
  899         error = VFS_STATFS(vp->v_mount, &sfs, td);
  900         if (error != 0)
  901                 goto out;
  902         if (sfs.f_maxfilesize) {
  903                 if (offset > sfs.f_maxfilesize || len > sfs.f_maxfilesize ||
  904                     offset + len > sfs.f_maxfilesize) {
  905                         error = EFBIG;
  906                         goto out;
  907                 }
  908         } else
  909 #endif
  910         if (offset + len > vap->va_size) {
  911                 /*
  912                  * Test offset + len against the filesystem's maxfilesize.
  913                  */
  914                 VATTR_NULL(vap);
  915                 vap->va_size = offset + len;
  916                 error = VOP_SETATTR(vp, vap, td->td_ucred);
  917                 if (error != 0)
  918                         goto out;
  919                 VATTR_NULL(vap);
  920                 vap->va_size = fsize;
  921                 error = VOP_SETATTR(vp, vap, td->td_ucred);
  922                 if (error != 0)
  923                         goto out;
  924         }
  925 
  926         for (;;) {
  927                 /*
  928                  * Read and write back anything below the nominal file
  929                  * size.  There's currently no way outside the filesystem
  930                  * to know whether this area is sparse or not.
  931                  */
  932                 cur = iosize;
  933                 if ((offset % iosize) != 0)
  934                         cur -= (offset % iosize);
  935                 if (cur > len)
  936                         cur = len;
  937                 if (offset < fsize) {
  938                         aiov.iov_base = buf;
  939                         aiov.iov_len = cur;
  940                         auio.uio_iov = &aiov;
  941                         auio.uio_iovcnt = 1;
  942                         auio.uio_offset = offset;
  943                         auio.uio_resid = cur;
  944                         auio.uio_segflg = UIO_SYSSPACE;
  945                         auio.uio_rw = UIO_READ;
  946                         auio.uio_td = td;
  947                         error = VOP_READ(vp, &auio, 0, td->td_ucred);
  948                         if (error != 0)
  949                                 break;
  950                         if (auio.uio_resid > 0) {
  951                                 bzero(buf + cur - auio.uio_resid,
  952                                     auio.uio_resid);
  953                         }
  954                 } else {
  955                         bzero(buf, cur);
  956                 }
  957 
  958                 aiov.iov_base = buf;
  959                 aiov.iov_len = cur;
  960                 auio.uio_iov = &aiov;
  961                 auio.uio_iovcnt = 1;
  962                 auio.uio_offset = offset;
  963                 auio.uio_resid = cur;
  964                 auio.uio_segflg = UIO_SYSSPACE;
  965                 auio.uio_rw = UIO_WRITE;
  966                 auio.uio_td = td;
  967 
  968                 error = VOP_WRITE(vp, &auio, 0, td->td_ucred);
  969                 if (error != 0)
  970                         break;
  971 
  972                 len -= cur;
  973                 offset += cur;
  974                 if (len == 0)
  975                         break;
  976                 if (should_yield())
  977                         break;
  978         }
  979 
  980  out:
  981         *ap->a_len = len;
  982         *ap->a_offset = offset;
  983         free(buf, M_TEMP);
  984         return (error);
  985 }
  986 
  987 /*
  988  * vfs default ops
  989  * used to fill the vfs function table to get reasonable default return values.
  990  */
  991 int
  992 vfs_stdroot (mp, flags, vpp)
  993         struct mount *mp;
  994         int flags;
  995         struct vnode **vpp;
  996 {
  997 
  998         return (EOPNOTSUPP);
  999 }
 1000 
 1001 int
 1002 vfs_stdstatfs (mp, sbp)
 1003         struct mount *mp;
 1004         struct statfs *sbp;
 1005 {
 1006 
 1007         return (EOPNOTSUPP);
 1008 }
 1009 
 1010 int
 1011 vfs_stdquotactl (mp, cmds, uid, arg)
 1012         struct mount *mp;
 1013         int cmds;
 1014         uid_t uid;
 1015         void *arg;
 1016 {
 1017 
 1018         return (EOPNOTSUPP);
 1019 }
 1020 
 1021 int
 1022 vfs_stdsync(mp, waitfor)
 1023         struct mount *mp;
 1024         int waitfor;
 1025 {
 1026         struct vnode *vp, *mvp;
 1027         struct thread *td;
 1028         int error, lockreq, allerror = 0;
 1029 
 1030         td = curthread;
 1031         lockreq = LK_EXCLUSIVE | LK_INTERLOCK;
 1032         if (waitfor != MNT_WAIT)
 1033                 lockreq |= LK_NOWAIT;
 1034         /*
 1035          * Force stale buffer cache information to be flushed.
 1036          */
 1037         MNT_ILOCK(mp);
 1038 loop:
 1039         MNT_VNODE_FOREACH(vp, mp, mvp) {
 1040                 /* bv_cnt is an acceptable race here. */
 1041                 if (vp->v_bufobj.bo_dirty.bv_cnt == 0)
 1042                         continue;
 1043                 VI_LOCK(vp);
 1044                 MNT_IUNLOCK(mp);
 1045                 if ((error = vget(vp, lockreq, td)) != 0) {
 1046                         MNT_ILOCK(mp);
 1047                         if (error == ENOENT) {
 1048                                 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
 1049                                 goto loop;
 1050                         }
 1051                         continue;
 1052                 }
 1053                 error = VOP_FSYNC(vp, waitfor, td);
 1054                 if (error)
 1055                         allerror = error;
 1056                 vput(vp);
 1057                 MNT_ILOCK(mp);
 1058         }
 1059         MNT_IUNLOCK(mp);
 1060         return (allerror);
 1061 }
 1062 
 1063 int
 1064 vfs_stdnosync (mp, waitfor)
 1065         struct mount *mp;
 1066         int waitfor;
 1067 {
 1068 
 1069         return (0);
 1070 }
 1071 
 1072 int
 1073 vfs_stdvget (mp, ino, flags, vpp)
 1074         struct mount *mp;
 1075         ino_t ino;
 1076         int flags;
 1077         struct vnode **vpp;
 1078 {
 1079 
 1080         return (EOPNOTSUPP);
 1081 }
 1082 
 1083 int
 1084 vfs_stdfhtovp (mp, fhp, flags, vpp)
 1085         struct mount *mp;
 1086         struct fid *fhp;
 1087         int flags;
 1088         struct vnode **vpp;
 1089 {
 1090 
 1091         return (EOPNOTSUPP);
 1092 }
 1093 
 1094 int
 1095 vfs_stdinit (vfsp)
 1096         struct vfsconf *vfsp;
 1097 {
 1098 
 1099         return (0);
 1100 }
 1101 
 1102 int
 1103 vfs_stduninit (vfsp)
 1104         struct vfsconf *vfsp;
 1105 {
 1106 
 1107         return(0);
 1108 }
 1109 
 1110 int
 1111 vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname)
 1112         struct mount *mp;
 1113         int cmd;
 1114         struct vnode *filename_vp;
 1115         int attrnamespace;
 1116         const char *attrname;
 1117 {
 1118 
 1119         if (filename_vp != NULL)
 1120                 VOP_UNLOCK(filename_vp, 0);
 1121         return (EOPNOTSUPP);
 1122 }
 1123 
 1124 int
 1125 vfs_stdsysctl(mp, op, req)
 1126         struct mount *mp;
 1127         fsctlop_t op;
 1128         struct sysctl_req *req;
 1129 {
 1130 
 1131         return (EOPNOTSUPP);
 1132 }
 1133 
 1134 /* end of vfs default ops */

Cache object: f19ec67f3d1c4a9ab9ac2f755fc1a415


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