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/8.2/sys/kern/vfs_default.c 212137 2010-09-02 04:56:01Z brian $");
   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_bmap =             vop_stdbmap,
  102         .vop_close =            VOP_NULL,
  103         .vop_fsync =            VOP_NULL,
  104         .vop_getpages =         vop_stdgetpages,
  105         .vop_getwritemount =    vop_stdgetwritemount,
  106         .vop_inactive =         VOP_NULL,
  107         .vop_ioctl =            VOP_ENOTTY,
  108         .vop_kqfilter =         vop_stdkqfilter,
  109         .vop_islocked =         vop_stdislocked,
  110         .vop_lock1 =            vop_stdlock,
  111         .vop_lookup =           vop_nolookup,
  112         .vop_open =             VOP_NULL,
  113         .vop_pathconf =         VOP_EINVAL,
  114         .vop_poll =             vop_nopoll,
  115         .vop_putpages =         vop_stdputpages,
  116         .vop_readlink =         VOP_EINVAL,
  117         .vop_rename =           vop_norename,
  118         .vop_revoke =           VOP_PANIC,
  119         .vop_strategy =         vop_nostrategy,
  120         .vop_unlock =           vop_stdunlock,
  121         .vop_vptocnp =          vop_stdvptocnp,
  122         .vop_vptofh =           vop_stdvptofh,
  123 };
  124 
  125 /*
  126  * Series of placeholder functions for various error returns for
  127  * VOPs.
  128  */
  129 
  130 int
  131 vop_eopnotsupp(struct vop_generic_args *ap)
  132 {
  133         /*
  134         printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name);
  135         */
  136 
  137         return (EOPNOTSUPP);
  138 }
  139 
  140 int
  141 vop_ebadf(struct vop_generic_args *ap)
  142 {
  143 
  144         return (EBADF);
  145 }
  146 
  147 int
  148 vop_enotty(struct vop_generic_args *ap)
  149 {
  150 
  151         return (ENOTTY);
  152 }
  153 
  154 int
  155 vop_einval(struct vop_generic_args *ap)
  156 {
  157 
  158         return (EINVAL);
  159 }
  160 
  161 int
  162 vop_enoent(struct vop_generic_args *ap)
  163 {
  164 
  165         return (ENOENT);
  166 }
  167 
  168 int
  169 vop_null(struct vop_generic_args *ap)
  170 {
  171 
  172         return (0);
  173 }
  174 
  175 /*
  176  * Helper function to panic on some bad VOPs in some filesystems.
  177  */
  178 int
  179 vop_panic(struct vop_generic_args *ap)
  180 {
  181 
  182         panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name);
  183 }
  184 
  185 /*
  186  * vop_std<something> and vop_no<something> are default functions for use by
  187  * filesystems that need the "default reasonable" implementation for a
  188  * particular operation.
  189  *
  190  * The documentation for the operations they implement exists (if it exists)
  191  * in the VOP_<SOMETHING>(9) manpage (all uppercase).
  192  */
  193 
  194 /*
  195  * Default vop for filesystems that do not support name lookup
  196  */
  197 static int
  198 vop_nolookup(ap)
  199         struct vop_lookup_args /* {
  200                 struct vnode *a_dvp;
  201                 struct vnode **a_vpp;
  202                 struct componentname *a_cnp;
  203         } */ *ap;
  204 {
  205 
  206         *ap->a_vpp = NULL;
  207         return (ENOTDIR);
  208 }
  209 
  210 /*
  211  * vop_norename:
  212  *
  213  * Handle unlock and reference counting for arguments of vop_rename
  214  * for filesystems that do not implement rename operation.
  215  */
  216 static int
  217 vop_norename(struct vop_rename_args *ap)
  218 {
  219 
  220         vop_rename_fail(ap);
  221         return (EOPNOTSUPP);
  222 }
  223 
  224 /*
  225  *      vop_nostrategy:
  226  *
  227  *      Strategy routine for VFS devices that have none.
  228  *
  229  *      BIO_ERROR and B_INVAL must be cleared prior to calling any strategy
  230  *      routine.  Typically this is done for a BIO_READ strategy call.
  231  *      Typically B_INVAL is assumed to already be clear prior to a write
  232  *      and should not be cleared manually unless you just made the buffer
  233  *      invalid.  BIO_ERROR should be cleared either way.
  234  */
  235 
  236 static int
  237 vop_nostrategy (struct vop_strategy_args *ap)
  238 {
  239         printf("No strategy for buffer at %p\n", ap->a_bp);
  240         vprint("vnode", ap->a_vp);
  241         ap->a_bp->b_ioflags |= BIO_ERROR;
  242         ap->a_bp->b_error = EOPNOTSUPP;
  243         bufdone(ap->a_bp);
  244         return (EOPNOTSUPP);
  245 }
  246 
  247 static int
  248 get_next_dirent(struct vnode *vp, struct dirent **dpp, char *dirbuf,
  249                 int dirbuflen, off_t *off, char **cpos, int *len,
  250                 int *eofflag, struct thread *td)
  251 {
  252         int error, reclen;
  253         struct uio uio;
  254         struct iovec iov;
  255         struct dirent *dp;
  256 
  257         KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
  258         KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
  259 
  260         if (*len == 0) {
  261                 iov.iov_base = dirbuf;
  262                 iov.iov_len = dirbuflen;
  263 
  264                 uio.uio_iov = &iov;
  265                 uio.uio_iovcnt = 1;
  266                 uio.uio_offset = *off;
  267                 uio.uio_resid = dirbuflen;
  268                 uio.uio_segflg = UIO_SYSSPACE;
  269                 uio.uio_rw = UIO_READ;
  270                 uio.uio_td = td;
  271 
  272                 *eofflag = 0;
  273 
  274 #ifdef MAC
  275                 error = mac_vnode_check_readdir(td->td_ucred, vp);
  276                 if (error == 0)
  277 #endif
  278                         error = VOP_READDIR(vp, &uio, td->td_ucred, eofflag,
  279                                 NULL, NULL);
  280                 if (error)
  281                         return (error);
  282 
  283                 *off = uio.uio_offset;
  284 
  285                 *cpos = dirbuf;
  286                 *len = (dirbuflen - uio.uio_resid);
  287 
  288                 if (*len == 0)
  289                         return (ENOENT);
  290         }
  291 
  292         dp = (struct dirent *)(*cpos);
  293         reclen = dp->d_reclen;
  294         *dpp = dp;
  295 
  296         /* check for malformed directory.. */
  297         if (reclen < DIRENT_MINSIZE)
  298                 return (EINVAL);
  299 
  300         *cpos += reclen;
  301         *len -= reclen;
  302 
  303         return (0);
  304 }
  305 
  306 /*
  307  * Check if a named file exists in a given directory vnode.
  308  */
  309 static int
  310 dirent_exists(struct vnode *vp, const char *dirname, struct thread *td)
  311 {
  312         char *dirbuf, *cpos;
  313         int error, eofflag, dirbuflen, len, found;
  314         off_t off;
  315         struct dirent *dp;
  316         struct vattr va;
  317 
  318         KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
  319         KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
  320 
  321         found = 0;
  322 
  323         error = VOP_GETATTR(vp, &va, td->td_ucred);
  324         if (error)
  325                 return (found);
  326 
  327         dirbuflen = DEV_BSIZE;
  328         if (dirbuflen < va.va_blocksize)
  329                 dirbuflen = va.va_blocksize;
  330         dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
  331 
  332         off = 0;
  333         len = 0;
  334         do {
  335                 error = get_next_dirent(vp, &dp, dirbuf, dirbuflen, &off,
  336                                         &cpos, &len, &eofflag, td);
  337                 if (error)
  338                         goto out;
  339 
  340                 if ((dp->d_type != DT_WHT) &&
  341                     !strcmp(dp->d_name, dirname)) {
  342                         found = 1;
  343                         goto out;
  344                 }
  345         } while (len > 0 || !eofflag);
  346 
  347 out:
  348         free(dirbuf, M_TEMP);
  349         return (found);
  350 }
  351 
  352 int
  353 vop_stdaccess(struct vop_access_args *ap)
  354 {
  355 
  356         KASSERT((ap->a_accmode & ~(VEXEC | VWRITE | VREAD | VADMIN |
  357             VAPPEND)) == 0, ("invalid bit in accmode"));
  358 
  359         return (VOP_ACCESSX(ap->a_vp, ap->a_accmode, ap->a_cred, ap->a_td));
  360 }
  361 
  362 int
  363 vop_stdaccessx(struct vop_accessx_args *ap)
  364 {
  365         int error;
  366         accmode_t accmode = ap->a_accmode;
  367 
  368         error = vfs_unixify_accmode(&accmode);
  369         if (error != 0)
  370                 return (error);
  371 
  372         if (accmode == 0)
  373                 return (0);
  374 
  375         return (VOP_ACCESS(ap->a_vp, accmode, ap->a_cred, ap->a_td));
  376 }
  377 
  378 /*
  379  * Advisory record locking support
  380  */
  381 int
  382 vop_stdadvlock(struct vop_advlock_args *ap)
  383 {
  384         struct vnode *vp;
  385         struct ucred *cred;
  386         struct vattr vattr;
  387         int error;
  388 
  389         vp = ap->a_vp;
  390         cred = curthread->td_ucred;
  391         vn_lock(vp, LK_SHARED | LK_RETRY);
  392         error = VOP_GETATTR(vp, &vattr, cred);
  393         VOP_UNLOCK(vp, 0);
  394         if (error)
  395                 return (error);
  396 
  397         return (lf_advlock(ap, &(vp->v_lockf), vattr.va_size));
  398 }
  399 
  400 int
  401 vop_stdadvlockasync(struct vop_advlockasync_args *ap)
  402 {
  403         struct vnode *vp;
  404         struct ucred *cred;
  405         struct vattr vattr;
  406         int error;
  407 
  408         vp = ap->a_vp;
  409         cred = curthread->td_ucred;
  410         vn_lock(vp, LK_SHARED | LK_RETRY);
  411         error = VOP_GETATTR(vp, &vattr, cred);
  412         VOP_UNLOCK(vp, 0);
  413         if (error)
  414                 return (error);
  415 
  416         return (lf_advlockasync(ap, &(vp->v_lockf), vattr.va_size));
  417 }
  418 
  419 /*
  420  * vop_stdpathconf:
  421  *
  422  * Standard implementation of POSIX pathconf, to get information about limits
  423  * for a filesystem.
  424  * Override per filesystem for the case where the filesystem has smaller
  425  * limits.
  426  */
  427 int
  428 vop_stdpathconf(ap)
  429         struct vop_pathconf_args /* {
  430         struct vnode *a_vp;
  431         int a_name;
  432         int *a_retval;
  433         } */ *ap;
  434 {
  435 
  436         switch (ap->a_name) {
  437                 case _PC_NAME_MAX:
  438                         *ap->a_retval = NAME_MAX;
  439                         return (0);
  440                 case _PC_PATH_MAX:
  441                         *ap->a_retval = PATH_MAX;
  442                         return (0);
  443                 case _PC_LINK_MAX:
  444                         *ap->a_retval = LINK_MAX;
  445                         return (0);
  446                 case _PC_MAX_CANON:
  447                         *ap->a_retval = MAX_CANON;
  448                         return (0);
  449                 case _PC_MAX_INPUT:
  450                         *ap->a_retval = MAX_INPUT;
  451                         return (0);
  452                 case _PC_PIPE_BUF:
  453                         *ap->a_retval = PIPE_BUF;
  454                         return (0);
  455                 case _PC_CHOWN_RESTRICTED:
  456                         *ap->a_retval = 1;
  457                         return (0);
  458                 case _PC_VDISABLE:
  459                         *ap->a_retval = _POSIX_VDISABLE;
  460                         return (0);
  461                 default:
  462                         return (EINVAL);
  463         }
  464         /* NOTREACHED */
  465 }
  466 
  467 /*
  468  * Standard lock, unlock and islocked functions.
  469  */
  470 int
  471 vop_stdlock(ap)
  472         struct vop_lock1_args /* {
  473                 struct vnode *a_vp;
  474                 int a_flags;
  475                 char *file;
  476                 int line;
  477         } */ *ap;
  478 {
  479         struct vnode *vp = ap->a_vp;
  480 
  481         return (_lockmgr_args(vp->v_vnlock, ap->a_flags, VI_MTX(vp),
  482             LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, ap->a_file,
  483             ap->a_line));
  484 }
  485 
  486 /* See above. */
  487 int
  488 vop_stdunlock(ap)
  489         struct vop_unlock_args /* {
  490                 struct vnode *a_vp;
  491                 int a_flags;
  492         } */ *ap;
  493 {
  494         struct vnode *vp = ap->a_vp;
  495 
  496         return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp)));
  497 }
  498 
  499 /* See above. */
  500 int
  501 vop_stdislocked(ap)
  502         struct vop_islocked_args /* {
  503                 struct vnode *a_vp;
  504         } */ *ap;
  505 {
  506 
  507         return (lockstatus(ap->a_vp->v_vnlock));
  508 }
  509 
  510 /*
  511  * Return true for select/poll.
  512  */
  513 int
  514 vop_nopoll(ap)
  515         struct vop_poll_args /* {
  516                 struct vnode *a_vp;
  517                 int  a_events;
  518                 struct ucred *a_cred;
  519                 struct thread *a_td;
  520         } */ *ap;
  521 {
  522 
  523         return (poll_no_poll(ap->a_events));
  524 }
  525 
  526 /*
  527  * Implement poll for local filesystems that support it.
  528  */
  529 int
  530 vop_stdpoll(ap)
  531         struct vop_poll_args /* {
  532                 struct vnode *a_vp;
  533                 int  a_events;
  534                 struct ucred *a_cred;
  535                 struct thread *a_td;
  536         } */ *ap;
  537 {
  538         if (ap->a_events & ~POLLSTANDARD)
  539                 return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events));
  540         return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
  541 }
  542 
  543 /*
  544  * Return our mount point, as we will take charge of the writes.
  545  */
  546 int
  547 vop_stdgetwritemount(ap)
  548         struct vop_getwritemount_args /* {
  549                 struct vnode *a_vp;
  550                 struct mount **a_mpp;
  551         } */ *ap;
  552 {
  553         struct mount *mp;
  554 
  555         /*
  556          * XXX Since this is called unlocked we may be recycled while
  557          * attempting to ref the mount.  If this is the case or mountpoint
  558          * will be set to NULL.  We only have to prevent this call from
  559          * returning with a ref to an incorrect mountpoint.  It is not
  560          * harmful to return with a ref to our previous mountpoint.
  561          */
  562         mp = ap->a_vp->v_mount;
  563         if (mp != NULL) {
  564                 vfs_ref(mp);
  565                 if (mp != ap->a_vp->v_mount) {
  566                         vfs_rel(mp);
  567                         mp = NULL;
  568                 }
  569         }
  570         *(ap->a_mpp) = mp;
  571         return (0);
  572 }
  573 
  574 /* XXX Needs good comment and VOP_BMAP(9) manpage */
  575 int
  576 vop_stdbmap(ap)
  577         struct vop_bmap_args /* {
  578                 struct vnode *a_vp;
  579                 daddr_t  a_bn;
  580                 struct bufobj **a_bop;
  581                 daddr_t *a_bnp;
  582                 int *a_runp;
  583                 int *a_runb;
  584         } */ *ap;
  585 {
  586 
  587         if (ap->a_bop != NULL)
  588                 *ap->a_bop = &ap->a_vp->v_bufobj;
  589         if (ap->a_bnp != NULL)
  590                 *ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize);
  591         if (ap->a_runp != NULL)
  592                 *ap->a_runp = 0;
  593         if (ap->a_runb != NULL)
  594                 *ap->a_runb = 0;
  595         return (0);
  596 }
  597 
  598 int
  599 vop_stdfsync(ap)
  600         struct vop_fsync_args /* {
  601                 struct vnode *a_vp;
  602                 struct ucred *a_cred;
  603                 int a_waitfor;
  604                 struct thread *a_td;
  605         } */ *ap;
  606 {
  607         struct vnode *vp = ap->a_vp;
  608         struct buf *bp;
  609         struct bufobj *bo;
  610         struct buf *nbp;
  611         int error = 0;
  612         int maxretry = 1000;     /* large, arbitrarily chosen */
  613 
  614         bo = &vp->v_bufobj;
  615         BO_LOCK(bo);
  616 loop1:
  617         /*
  618          * MARK/SCAN initialization to avoid infinite loops.
  619          */
  620         TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
  621                 bp->b_vflags &= ~BV_SCANNED;
  622                 bp->b_error = 0;
  623         }
  624 
  625         /*
  626          * Flush all dirty buffers associated with a vnode.
  627          */
  628 loop2:
  629         TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
  630                 if ((bp->b_vflags & BV_SCANNED) != 0)
  631                         continue;
  632                 bp->b_vflags |= BV_SCANNED;
  633                 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL))
  634                         continue;
  635                 BO_UNLOCK(bo);
  636                 KASSERT(bp->b_bufobj == bo,
  637                     ("bp %p wrong b_bufobj %p should be %p",
  638                     bp, bp->b_bufobj, bo));
  639                 if ((bp->b_flags & B_DELWRI) == 0)
  640                         panic("fsync: not dirty");
  641                 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
  642                         vfs_bio_awrite(bp);
  643                 } else {
  644                         bremfree(bp);
  645                         bawrite(bp);
  646                 }
  647                 BO_LOCK(bo);
  648                 goto loop2;
  649         }
  650 
  651         /*
  652          * If synchronous the caller expects us to completely resolve all
  653          * dirty buffers in the system.  Wait for in-progress I/O to
  654          * complete (which could include background bitmap writes), then
  655          * retry if dirty blocks still exist.
  656          */
  657         if (ap->a_waitfor == MNT_WAIT) {
  658                 bufobj_wwait(bo, 0, 0);
  659                 if (bo->bo_dirty.bv_cnt > 0) {
  660                         /*
  661                          * If we are unable to write any of these buffers
  662                          * then we fail now rather than trying endlessly
  663                          * to write them out.
  664                          */
  665                         TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
  666                                 if ((error = bp->b_error) == 0)
  667                                         continue;
  668                         if (error == 0 && --maxretry >= 0)
  669                                 goto loop1;
  670                         error = EAGAIN;
  671                 }
  672         }
  673         BO_UNLOCK(bo);
  674         if (error == EAGAIN)
  675                 vprint("fsync: giving up on dirty", vp);
  676 
  677         return (error);
  678 }
  679 
  680 /* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */
  681 int
  682 vop_stdgetpages(ap)
  683         struct vop_getpages_args /* {
  684                 struct vnode *a_vp;
  685                 vm_page_t *a_m;
  686                 int a_count;
  687                 int a_reqpage;
  688                 vm_ooffset_t a_offset;
  689         } */ *ap;
  690 {
  691 
  692         return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
  693             ap->a_count, ap->a_reqpage);
  694 }
  695 
  696 int
  697 vop_stdkqfilter(struct vop_kqfilter_args *ap)
  698 {
  699         return vfs_kqfilter(ap);
  700 }
  701 
  702 /* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */
  703 int
  704 vop_stdputpages(ap)
  705         struct vop_putpages_args /* {
  706                 struct vnode *a_vp;
  707                 vm_page_t *a_m;
  708                 int a_count;
  709                 int a_sync;
  710                 int *a_rtvals;
  711                 vm_ooffset_t a_offset;
  712         } */ *ap;
  713 {
  714 
  715         return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
  716              ap->a_sync, ap->a_rtvals);
  717 }
  718 
  719 int
  720 vop_stdvptofh(struct vop_vptofh_args *ap)
  721 {
  722         return (EOPNOTSUPP);
  723 }
  724 
  725 int
  726 vop_stdvptocnp(struct vop_vptocnp_args *ap)
  727 {
  728         struct vnode *vp = ap->a_vp;
  729         struct vnode **dvp = ap->a_vpp;
  730         struct ucred *cred = ap->a_cred;
  731         char *buf = ap->a_buf;
  732         int *buflen = ap->a_buflen;
  733         char *dirbuf, *cpos;
  734         int i, error, eofflag, dirbuflen, flags, locked, len, covered;
  735         off_t off;
  736         ino_t fileno;
  737         struct vattr va;
  738         struct nameidata nd;
  739         struct thread *td;
  740         struct dirent *dp;
  741         struct vnode *mvp;
  742 
  743         i = *buflen;
  744         error = 0;
  745         covered = 0;
  746         td = curthread;
  747 
  748         if (vp->v_type != VDIR)
  749                 return (ENOENT);
  750 
  751         error = VOP_GETATTR(vp, &va, cred);
  752         if (error)
  753                 return (error);
  754 
  755         VREF(vp);
  756         locked = VOP_ISLOCKED(vp);
  757         VOP_UNLOCK(vp, 0);
  758         NDINIT_ATVP(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
  759             "..", vp, td);
  760         flags = FREAD;
  761         error = vn_open_cred(&nd, &flags, 0, VN_OPEN_NOAUDIT, cred, NULL);
  762         if (error) {
  763                 vn_lock(vp, locked | LK_RETRY);
  764                 return (error);
  765         }
  766         NDFREE(&nd, NDF_ONLY_PNBUF);
  767 
  768         mvp = *dvp = nd.ni_vp;
  769 
  770         if (vp->v_mount != (*dvp)->v_mount &&
  771             ((*dvp)->v_vflag & VV_ROOT) &&
  772             ((*dvp)->v_mount->mnt_flag & MNT_UNION)) {
  773                 *dvp = (*dvp)->v_mount->mnt_vnodecovered;
  774                 VREF(mvp);
  775                 VOP_UNLOCK(mvp, 0);
  776                 vn_close(mvp, FREAD, cred, td);
  777                 VREF(*dvp);
  778                 vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  779                 covered = 1;
  780         }
  781 
  782         fileno = va.va_fileid;
  783 
  784         dirbuflen = DEV_BSIZE;
  785         if (dirbuflen < va.va_blocksize)
  786                 dirbuflen = va.va_blocksize;
  787         dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
  788 
  789         if ((*dvp)->v_type != VDIR) {
  790                 error = ENOENT;
  791                 goto out;
  792         }
  793 
  794         off = 0;
  795         len = 0;
  796         do {
  797                 /* call VOP_READDIR of parent */
  798                 error = get_next_dirent(*dvp, &dp, dirbuf, dirbuflen, &off,
  799                                         &cpos, &len, &eofflag, td);
  800                 if (error)
  801                         goto out;
  802 
  803                 if ((dp->d_type != DT_WHT) &&
  804                     (dp->d_fileno == fileno)) {
  805                         if (covered) {
  806                                 VOP_UNLOCK(*dvp, 0);
  807                                 vn_lock(mvp, LK_EXCLUSIVE | LK_RETRY);
  808                                 if (dirent_exists(mvp, dp->d_name, td)) {
  809                                         error = ENOENT;
  810                                         VOP_UNLOCK(mvp, 0);
  811                                         vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  812                                         goto out;
  813                                 }
  814                                 VOP_UNLOCK(mvp, 0);
  815                                 vn_lock(*dvp, LK_EXCLUSIVE | LK_RETRY);
  816                         }
  817                         i -= dp->d_namlen;
  818 
  819                         if (i < 0) {
  820                                 error = ENOMEM;
  821                                 goto out;
  822                         }
  823                         bcopy(dp->d_name, buf + i, dp->d_namlen);
  824                         error = 0;
  825                         goto out;
  826                 }
  827         } while (len > 0 || !eofflag);
  828         error = ENOENT;
  829 
  830 out:
  831         free(dirbuf, M_TEMP);
  832         if (!error) {
  833                 *buflen = i;
  834                 vhold(*dvp);
  835         }
  836         if (covered) {
  837                 vput(*dvp);
  838                 vrele(mvp);
  839         } else {
  840                 VOP_UNLOCK(mvp, 0);
  841                 vn_close(mvp, FREAD, cred, td);
  842         }
  843         vn_lock(vp, locked | LK_RETRY);
  844         return (error);
  845 }
  846 
  847 /*
  848  * vfs default ops
  849  * used to fill the vfs function table to get reasonable default return values.
  850  */
  851 int
  852 vfs_stdroot (mp, flags, vpp)
  853         struct mount *mp;
  854         int flags;
  855         struct vnode **vpp;
  856 {
  857 
  858         return (EOPNOTSUPP);
  859 }
  860 
  861 int
  862 vfs_stdstatfs (mp, sbp)
  863         struct mount *mp;
  864         struct statfs *sbp;
  865 {
  866 
  867         return (EOPNOTSUPP);
  868 }
  869 
  870 int
  871 vfs_stdquotactl (mp, cmds, uid, arg)
  872         struct mount *mp;
  873         int cmds;
  874         uid_t uid;
  875         void *arg;
  876 {
  877 
  878         return (EOPNOTSUPP);
  879 }
  880 
  881 int
  882 vfs_stdsync(mp, waitfor)
  883         struct mount *mp;
  884         int waitfor;
  885 {
  886         struct vnode *vp, *mvp;
  887         struct thread *td;
  888         int error, lockreq, allerror = 0;
  889 
  890         td = curthread;
  891         lockreq = LK_EXCLUSIVE | LK_INTERLOCK;
  892         if (waitfor != MNT_WAIT)
  893                 lockreq |= LK_NOWAIT;
  894         /*
  895          * Force stale buffer cache information to be flushed.
  896          */
  897         MNT_ILOCK(mp);
  898 loop:
  899         MNT_VNODE_FOREACH(vp, mp, mvp) {
  900                 /* bv_cnt is an acceptable race here. */
  901                 if (vp->v_bufobj.bo_dirty.bv_cnt == 0)
  902                         continue;
  903                 VI_LOCK(vp);
  904                 MNT_IUNLOCK(mp);
  905                 if ((error = vget(vp, lockreq, td)) != 0) {
  906                         MNT_ILOCK(mp);
  907                         if (error == ENOENT) {
  908                                 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
  909                                 goto loop;
  910                         }
  911                         continue;
  912                 }
  913                 error = VOP_FSYNC(vp, waitfor, td);
  914                 if (error)
  915                         allerror = error;
  916 
  917                 /* Do not turn this into vput.  td is not always curthread. */
  918                 VOP_UNLOCK(vp, 0);
  919                 vrele(vp);
  920                 MNT_ILOCK(mp);
  921         }
  922         MNT_IUNLOCK(mp);
  923         return (allerror);
  924 }
  925 
  926 int
  927 vfs_stdnosync (mp, waitfor)
  928         struct mount *mp;
  929         int waitfor;
  930 {
  931 
  932         return (0);
  933 }
  934 
  935 int
  936 vfs_stdvget (mp, ino, flags, vpp)
  937         struct mount *mp;
  938         ino_t ino;
  939         int flags;
  940         struct vnode **vpp;
  941 {
  942 
  943         return (EOPNOTSUPP);
  944 }
  945 
  946 int
  947 vfs_stdfhtovp (mp, fhp, vpp)
  948         struct mount *mp;
  949         struct fid *fhp;
  950         struct vnode **vpp;
  951 {
  952 
  953         return (EOPNOTSUPP);
  954 }
  955 
  956 int
  957 vfs_stdinit (vfsp)
  958         struct vfsconf *vfsp;
  959 {
  960 
  961         return (0);
  962 }
  963 
  964 int
  965 vfs_stduninit (vfsp)
  966         struct vfsconf *vfsp;
  967 {
  968 
  969         return(0);
  970 }
  971 
  972 int
  973 vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname)
  974         struct mount *mp;
  975         int cmd;
  976         struct vnode *filename_vp;
  977         int attrnamespace;
  978         const char *attrname;
  979 {
  980 
  981         if (filename_vp != NULL)
  982                 VOP_UNLOCK(filename_vp, 0);
  983         return (EOPNOTSUPP);
  984 }
  985 
  986 int
  987 vfs_stdsysctl(mp, op, req)
  988         struct mount *mp;
  989         fsctlop_t op;
  990         struct sysctl_req *req;
  991 {
  992 
  993         return (EOPNOTSUPP);
  994 }
  995 
  996 /* end of vfs default ops */

Cache object: fdd8af98628eb3534da76b668dfd3c72


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