The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_vnode.c

Version: -  FREEBSD  -  FREEBSD11  -  FREEBSD10  -  FREEBSD9  -  FREEBSD92  -  FREEBSD91  -  FREEBSD90  -  FREEBSD8  -  FREEBSD82  -  FREEBSD81  -  FREEBSD80  -  FREEBSD7  -  FREEBSD74  -  FREEBSD73  -  FREEBSD72  -  FREEBSD71  -  FREEBSD70  -  FREEBSD6  -  FREEBSD64  -  FREEBSD63  -  FREEBSD62  -  FREEBSD61  -  FREEBSD60  -  FREEBSD5  -  FREEBSD55  -  FREEBSD54  -  FREEBSD53  -  FREEBSD52  -  FREEBSD51  -  FREEBSD50  -  FREEBSD4  -  FREEBSD3  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: uvm_vnode.c,v 1.64 2005/01/09 16:42:44 chs Exp $       */
    2 
    3 /*
    4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
    5  * Copyright (c) 1991, 1993
    6  *      The Regents of the University of California.
    7  * Copyright (c) 1990 University of Utah.
    8  *
    9  * All rights reserved.
   10  *
   11  * This code is derived from software contributed to Berkeley by
   12  * the Systems Programming Group of the University of Utah Computer
   13  * Science Department.
   14  *
   15  * Redistribution and use in source and binary forms, with or without
   16  * modification, are permitted provided that the following conditions
   17  * are met:
   18  * 1. Redistributions of source code must retain the above copyright
   19  *    notice, this list of conditions and the following disclaimer.
   20  * 2. Redistributions in binary form must reproduce the above copyright
   21  *    notice, this list of conditions and the following disclaimer in the
   22  *    documentation and/or other materials provided with the distribution.
   23  * 3. All advertising materials mentioning features or use of this software
   24  *    must display the following acknowledgement:
   25  *      This product includes software developed by Charles D. Cranor,
   26  *      Washington University, the University of California, Berkeley and
   27  *      its contributors.
   28  * 4. Neither the name of the University nor the names of its contributors
   29  *    may be used to endorse or promote products derived from this software
   30  *    without specific prior written permission.
   31  *
   32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   42  * SUCH DAMAGE.
   43  *
   44  *      @(#)vnode_pager.c       8.8 (Berkeley) 2/13/94
   45  * from: Id: uvm_vnode.c,v 1.1.2.26 1998/02/02 20:38:07 chuck Exp
   46  */
   47 
   48 /*
   49  * uvm_vnode.c: the vnode pager.
   50  */
   51 
   52 #include <sys/cdefs.h>
   53 __KERNEL_RCSID(0, "$NetBSD: uvm_vnode.c,v 1.64 2005/01/09 16:42:44 chs Exp $");
   54 
   55 #include "fs_nfs.h"
   56 #include "opt_uvmhist.h"
   57 #include "opt_ddb.h"
   58 
   59 #include <sys/param.h>
   60 #include <sys/systm.h>
   61 #include <sys/kernel.h>
   62 #include <sys/proc.h>
   63 #include <sys/malloc.h>
   64 #include <sys/vnode.h>
   65 #include <sys/disklabel.h>
   66 #include <sys/ioctl.h>
   67 #include <sys/fcntl.h>
   68 #include <sys/conf.h>
   69 #include <sys/pool.h>
   70 #include <sys/mount.h>
   71 
   72 #include <miscfs/specfs/specdev.h>
   73 
   74 #include <uvm/uvm.h>
   75 
   76 /*
   77  * functions
   78  */
   79 
   80 void    uvn_detach(struct uvm_object *);
   81 int     uvn_get(struct uvm_object *, voff_t, struct vm_page **, int *, int,
   82             vm_prot_t, int, int);
   83 int     uvn_put(struct uvm_object *, voff_t, voff_t, int);
   84 void    uvn_reference(struct uvm_object *);
   85 
   86 int     uvn_findpage(struct uvm_object *, voff_t, struct vm_page **, int);
   87 
   88 /*
   89  * master pager structure
   90  */
   91 
   92 struct uvm_pagerops uvm_vnodeops = {
   93         NULL,
   94         uvn_reference,
   95         uvn_detach,
   96         NULL,
   97         uvn_get,
   98         uvn_put,
   99 };
  100 
  101 /*
  102  * the ops!
  103  */
  104 
  105 /*
  106  * uvn_attach
  107  *
  108  * attach a vnode structure to a VM object.  if the vnode is already
  109  * attached, then just bump the reference count by one and return the
  110  * VM object.   if not already attached, attach and return the new VM obj.
  111  * the "accessprot" tells the max access the attaching thread wants to
  112  * our pages.
  113  *
  114  * => caller must _not_ already be holding the lock on the uvm_object.
  115  * => in fact, nothing should be locked so that we can sleep here.
  116  * => note that uvm_object is first thing in vnode structure, so their
  117  *    pointers are equiv.
  118  */
  119 
  120 struct uvm_object *
  121 uvn_attach(arg, accessprot)
  122         void *arg;
  123         vm_prot_t accessprot;
  124 {
  125         struct vnode *vp = arg;
  126         struct uvm_object *uobj = &vp->v_uobj;
  127         struct vattr vattr;
  128         const struct bdevsw *bdev;
  129         int result;
  130         struct partinfo pi;
  131         voff_t used_vnode_size;
  132         UVMHIST_FUNC("uvn_attach"); UVMHIST_CALLED(maphist);
  133 
  134         UVMHIST_LOG(maphist, "(vn=0x%x)", arg,0,0,0);
  135         used_vnode_size = (voff_t)0;
  136 
  137         /*
  138          * first get a lock on the uobj.
  139          */
  140 
  141         simple_lock(&uobj->vmobjlock);
  142         while (vp->v_flag & VXLOCK) {
  143                 vp->v_flag |= VXWANT;
  144                 UVMHIST_LOG(maphist, "  SLEEPING on blocked vn",0,0,0,0);
  145                 UVM_UNLOCK_AND_WAIT(uobj, &uobj->vmobjlock, FALSE,
  146                     "uvn_attach", 0);
  147                 simple_lock(&uobj->vmobjlock);
  148                 UVMHIST_LOG(maphist,"  WOKE UP",0,0,0,0);
  149         }
  150 
  151         /*
  152          * if we're mapping a BLK device, make sure it is a disk.
  153          */
  154         if (vp->v_type == VBLK) {
  155                 bdev = bdevsw_lookup(vp->v_rdev);
  156                 if (bdev == NULL || bdev->d_type != D_DISK) {
  157                         simple_unlock(&uobj->vmobjlock);
  158                         UVMHIST_LOG(maphist,"<- done (VBLK not D_DISK!)",
  159                                     0,0,0,0);
  160                         return(NULL);
  161                 }
  162         }
  163         KASSERT(vp->v_type == VREG || vp->v_type == VBLK);
  164 
  165         /*
  166          * set up our idea of the size
  167          * if this hasn't been done already.
  168          */
  169         if (vp->v_size == VSIZENOTSET) {
  170 
  171 
  172         vp->v_flag |= VXLOCK;
  173         simple_unlock(&uobj->vmobjlock); /* drop lock in case we sleep */
  174                 /* XXX: curproc? */
  175         if (vp->v_type == VBLK) {
  176                 /*
  177                  * We could implement this as a specfs getattr call, but:
  178                  *
  179                  *      (1) VOP_GETATTR() would get the file system
  180                  *          vnode operation, not the specfs operation.
  181                  *
  182                  *      (2) All we want is the size, anyhow.
  183                  */
  184                 bdev = bdevsw_lookup(vp->v_rdev);
  185                 if (bdev != NULL) {
  186                         result = (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART,
  187                                                   (caddr_t)&pi, FREAD, curproc);
  188                 } else {
  189                         result = ENXIO;
  190                 }
  191                 if (result == 0) {
  192                         /* XXX should remember blocksize */
  193                         used_vnode_size = (voff_t)pi.disklab->d_secsize *
  194                             (voff_t)pi.part->p_size;
  195                 }
  196         } else {
  197                 result = VOP_GETATTR(vp, &vattr, curproc->p_ucred, curproc);
  198                 if (result == 0)
  199                         used_vnode_size = vattr.va_size;
  200         }
  201 
  202         /* relock object */
  203         simple_lock(&uobj->vmobjlock);
  204 
  205         if (vp->v_flag & VXWANT) {
  206                 wakeup(vp);
  207         }
  208         vp->v_flag &= ~(VXLOCK|VXWANT);
  209 
  210         if (result != 0) {
  211                 simple_unlock(&uobj->vmobjlock);
  212                 UVMHIST_LOG(maphist,"<- done (VOP_GETATTR FAILED!)", 0,0,0,0);
  213                 return(NULL);
  214         }
  215         vp->v_size = used_vnode_size;
  216 
  217         }
  218 
  219         simple_unlock(&uobj->vmobjlock);
  220         UVMHIST_LOG(maphist,"<- done, refcnt=%d", vp->v_usecount,
  221             0, 0, 0);
  222         return uobj;
  223 }
  224 
  225 
  226 /*
  227  * uvn_reference
  228  *
  229  * duplicate a reference to a VM object.  Note that the reference
  230  * count must already be at least one (the passed in reference) so
  231  * there is no chance of the uvn being killed or locked out here.
  232  *
  233  * => caller must call with object unlocked.
  234  * => caller must be using the same accessprot as was used at attach time
  235  */
  236 
  237 void
  238 uvn_reference(uobj)
  239         struct uvm_object *uobj;
  240 {
  241         VREF((struct vnode *)uobj);
  242 }
  243 
  244 
  245 /*
  246  * uvn_detach
  247  *
  248  * remove a reference to a VM object.
  249  *
  250  * => caller must call with object unlocked and map locked.
  251  */
  252 
  253 void
  254 uvn_detach(uobj)
  255         struct uvm_object *uobj;
  256 {
  257         vrele((struct vnode *)uobj);
  258 }
  259 
  260 /*
  261  * uvn_put: flush page data to backing store.
  262  *
  263  * => object must be locked on entry!   VOP_PUTPAGES must unlock it.
  264  * => flags: PGO_SYNCIO -- use sync. I/O
  265  * => note: caller must set PG_CLEAN and pmap_clear_modify (if needed)
  266  */
  267 
  268 int
  269 uvn_put(uobj, offlo, offhi, flags)
  270         struct uvm_object *uobj;
  271         voff_t offlo;
  272         voff_t offhi;
  273         int flags;
  274 {
  275         struct vnode *vp = (struct vnode *)uobj;
  276         int error;
  277 
  278         LOCK_ASSERT(simple_lock_held(&vp->v_interlock));
  279         error = VOP_PUTPAGES(vp, offlo, offhi, flags);
  280         LOCK_ASSERT(!simple_lock_held(&vp->v_interlock));
  281         return error;
  282 }
  283 
  284 
  285 /*
  286  * uvn_get: get pages (synchronously) from backing store
  287  *
  288  * => prefer map unlocked (not required)
  289  * => object must be locked!  we will _unlock_ it before starting any I/O.
  290  * => flags: PGO_ALLPAGES: get all of the pages
  291  *           PGO_LOCKED: fault data structures are locked
  292  * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx]
  293  * => NOTE: caller must check for released pages!!
  294  */
  295 
  296 int
  297 uvn_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags)
  298         struct uvm_object *uobj;
  299         voff_t offset;
  300         struct vm_page **pps;           /* IN/OUT */
  301         int *npagesp;                   /* IN (OUT if PGO_LOCKED) */
  302         int centeridx;
  303         vm_prot_t access_type;
  304         int advice, flags;
  305 {
  306         struct vnode *vp = (struct vnode *)uobj;
  307         int error;
  308         UVMHIST_FUNC("uvn_get"); UVMHIST_CALLED(ubchist);
  309 
  310         UVMHIST_LOG(ubchist, "vp %p off 0x%x", vp, (int)offset, 0,0);
  311         error = VOP_GETPAGES(vp, offset, pps, npagesp, centeridx,
  312                              access_type, advice, flags);
  313         return error;
  314 }
  315 
  316 
  317 /*
  318  * uvn_findpages:
  319  * return the page for the uobj and offset requested, allocating if needed.
  320  * => uobj must be locked.
  321  * => returned pages will be BUSY.
  322  */
  323 
  324 int
  325 uvn_findpages(uobj, offset, npagesp, pgs, flags)
  326         struct uvm_object *uobj;
  327         voff_t offset;
  328         int *npagesp;
  329         struct vm_page **pgs;
  330         int flags;
  331 {
  332         int i, count, found, npages, rv;
  333 
  334         count = found = 0;
  335         npages = *npagesp;
  336         if (flags & UFP_BACKWARD) {
  337                 for (i = npages - 1; i >= 0; i--, offset -= PAGE_SIZE) {
  338                         rv = uvn_findpage(uobj, offset, &pgs[i], flags);
  339                         if (rv == 0) {
  340                                 if (flags & UFP_DIRTYONLY)
  341                                         break;
  342                         } else
  343                                 found++;
  344                         count++;
  345                 }
  346         } else {
  347                 for (i = 0; i < npages; i++, offset += PAGE_SIZE) {
  348                         rv = uvn_findpage(uobj, offset, &pgs[i], flags);
  349                         if (rv == 0) {
  350                                 if (flags & UFP_DIRTYONLY)
  351                                         break;
  352                         } else
  353                                 found++;
  354                         count++;
  355                 }
  356         }
  357         *npagesp = count;
  358         return (found);
  359 }
  360 
  361 int
  362 uvn_findpage(uobj, offset, pgp, flags)
  363         struct uvm_object *uobj;
  364         voff_t offset;
  365         struct vm_page **pgp;
  366         int flags;
  367 {
  368         struct vm_page *pg;
  369         boolean_t dirty;
  370         UVMHIST_FUNC("uvn_findpage"); UVMHIST_CALLED(ubchist);
  371         UVMHIST_LOG(ubchist, "vp %p off 0x%lx", uobj, offset,0,0);
  372 
  373         if (*pgp != NULL) {
  374                 UVMHIST_LOG(ubchist, "dontcare", 0,0,0,0);
  375                 return 0;
  376         }
  377         for (;;) {
  378                 /* look for an existing page */
  379                 pg = uvm_pagelookup(uobj, offset);
  380 
  381                 /* nope?  allocate one now */
  382                 if (pg == NULL) {
  383                         if (flags & UFP_NOALLOC) {
  384                                 UVMHIST_LOG(ubchist, "noalloc", 0,0,0,0);
  385                                 return 0;
  386                         }
  387                         pg = uvm_pagealloc(uobj, offset, NULL, 0);
  388                         if (pg == NULL) {
  389                                 if (flags & UFP_NOWAIT) {
  390                                         UVMHIST_LOG(ubchist, "nowait",0,0,0,0);
  391                                         return 0;
  392                                 }
  393                                 simple_unlock(&uobj->vmobjlock);
  394                                 uvm_wait("uvn_fp1");
  395                                 simple_lock(&uobj->vmobjlock);
  396                                 continue;
  397                         }
  398                         UVMHIST_LOG(ubchist, "alloced %p", pg,0,0,0);
  399                         break;
  400                 } else if (flags & UFP_NOCACHE) {
  401                         UVMHIST_LOG(ubchist, "nocache",0,0,0,0);
  402                         return 0;
  403                 }
  404 
  405                 /* page is there, see if we need to wait on it */
  406                 if ((pg->flags & PG_BUSY) != 0) {
  407                         if (flags & UFP_NOWAIT) {
  408                                 UVMHIST_LOG(ubchist, "nowait",0,0,0,0);
  409                                 return 0;
  410                         }
  411                         pg->flags |= PG_WANTED;
  412                         UVMHIST_LOG(ubchist, "wait %p", pg,0,0,0);
  413                         UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
  414                                             "uvn_fp2", 0);
  415                         simple_lock(&uobj->vmobjlock);
  416                         continue;
  417                 }
  418 
  419                 /* skip PG_RDONLY pages if requested */
  420                 if ((flags & UFP_NORDONLY) && (pg->flags & PG_RDONLY)) {
  421                         UVMHIST_LOG(ubchist, "nordonly",0,0,0,0);
  422                         return 0;
  423                 }
  424 
  425                 /* stop on clean pages if requested */
  426                 if (flags & UFP_DIRTYONLY) {
  427                         dirty = pmap_clear_modify(pg) ||
  428                                 (pg->flags & PG_CLEAN) == 0;
  429                         pg->flags |= PG_CLEAN;
  430                         if (!dirty) {
  431                                 UVMHIST_LOG(ubchist, "dirtonly", 0,0,0,0);
  432                                 return 0;
  433                         }
  434                 }
  435 
  436                 /* mark the page BUSY and we're done. */
  437                 pg->flags |= PG_BUSY;
  438                 UVM_PAGE_OWN(pg, "uvn_findpage");
  439                 UVMHIST_LOG(ubchist, "found %p", pg,0,0,0);
  440                 break;
  441         }
  442         *pgp = pg;
  443         return 1;
  444 }
  445 
  446 /*
  447  * uvm_vnp_setsize: grow or shrink a vnode uobj
  448  *
  449  * grow   => just update size value
  450  * shrink => toss un-needed pages
  451  *
  452  * => we assume that the caller has a reference of some sort to the
  453  *      vnode in question so that it will not be yanked out from under
  454  *      us.
  455  */
  456 
  457 void
  458 uvm_vnp_setsize(vp, newsize)
  459         struct vnode *vp;
  460         voff_t newsize;
  461 {
  462         struct uvm_object *uobj = &vp->v_uobj;
  463         voff_t pgend = round_page(newsize);
  464         UVMHIST_FUNC("uvm_vnp_setsize"); UVMHIST_CALLED(ubchist);
  465 
  466         simple_lock(&uobj->vmobjlock);
  467         UVMHIST_LOG(ubchist, "vp %p old 0x%x new 0x%x",
  468             vp, vp->v_size, newsize, 0);
  469 
  470         /*
  471          * now check if the size has changed: if we shrink we had better
  472          * toss some pages...
  473          */
  474 
  475         if (vp->v_size > pgend && vp->v_size != VSIZENOTSET) {
  476                 (void) uvn_put(uobj, pgend, 0, PGO_FREE | PGO_SYNCIO);
  477         } else {
  478                 simple_unlock(&uobj->vmobjlock);
  479         }
  480         vp->v_size = newsize;
  481 }
  482 
  483 /*
  484  * uvm_vnp_zerorange:  set a range of bytes in a file to zero.
  485  */
  486 
  487 void
  488 uvm_vnp_zerorange(vp, off, len)
  489         struct vnode *vp;
  490         off_t off;
  491         size_t len;
  492 {
  493         void *win;
  494         int flags;
  495 
  496         /*
  497          * XXXUBC invent kzero() and use it
  498          */
  499 
  500         while (len) {
  501                 vsize_t bytelen = len;
  502 
  503                 win = ubc_alloc(&vp->v_uobj, off, &bytelen, UBC_WRITE);
  504                 memset(win, 0, bytelen);
  505                 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0;
  506                 ubc_release(win, flags);
  507 
  508                 off += bytelen;
  509                 len -= bytelen;
  510         }
  511 }

Cache object: 1e95398e07b1d3dbbb54a872cf916a6e


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.