Annotation of src/sys/uvm/uvm_vnode.c, Revision 1.69.10.1
1.69.10.1! elad 1: /* $NetBSD: uvm_vnode.c,v 1.69 2005/12/11 12:25:29 christos Exp $ */
1.1 mrg 2:
3: /*
4: * Copyright (c) 1997 Charles D. Cranor and Washington University.
5: * Copyright (c) 1991, 1993
1.49 chs 6: * The Regents of the University of California.
1.1 mrg 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,
1.49 chs 26: * Washington University, the University of California, Berkeley and
1.1 mrg 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
1.3 mrg 45: * from: Id: uvm_vnode.c,v 1.1.2.26 1998/02/02 20:38:07 chuck Exp
1.1 mrg 46: */
47:
1.55 lukem 48: /*
49: * uvm_vnode.c: the vnode pager.
50: */
51:
52: #include <sys/cdefs.h>
1.69.10.1! elad 53: __KERNEL_RCSID(0, "$NetBSD: uvm_vnode.c,v 1.69 2005/12/11 12:25:29 christos Exp $");
1.55 lukem 54:
1.6 thorpej 55: #include "fs_nfs.h"
1.4 mrg 56: #include "opt_uvmhist.h"
1.67 yamt 57: #include "opt_readahead.h"
1.37 chs 58: #include "opt_ddb.h"
1.1 mrg 59:
60: #include <sys/param.h>
61: #include <sys/systm.h>
1.37 chs 62: #include <sys/kernel.h>
1.1 mrg 63: #include <sys/proc.h>
64: #include <sys/malloc.h>
65: #include <sys/vnode.h>
1.13 thorpej 66: #include <sys/disklabel.h>
67: #include <sys/ioctl.h>
68: #include <sys/fcntl.h>
69: #include <sys/conf.h>
1.37 chs 70: #include <sys/pool.h>
71: #include <sys/mount.h>
1.13 thorpej 72:
73: #include <miscfs/specfs/specdev.h>
1.1 mrg 74:
75: #include <uvm/uvm.h>
1.68 yamt 76: #include <uvm/uvm_readahead.h>
1.1 mrg 77:
78: /*
79: * functions
80: */
81:
1.66 thorpej 82: static void uvn_detach(struct uvm_object *);
83: static int uvn_get(struct uvm_object *, voff_t, struct vm_page **, int *,
84: int, vm_prot_t, int, int);
85: static int uvn_put(struct uvm_object *, voff_t, voff_t, int);
86: static void uvn_reference(struct uvm_object *);
1.52 chs 87:
1.66 thorpej 88: static int uvn_findpage(struct uvm_object *, voff_t, struct vm_page **,
89: int);
1.1 mrg 90:
91: /*
92: * master pager structure
93: */
94:
95: struct uvm_pagerops uvm_vnodeops = {
1.37 chs 96: NULL,
1.8 mrg 97: uvn_reference,
98: uvn_detach,
1.37 chs 99: NULL,
1.8 mrg 100: uvn_get,
101: uvn_put,
1.1 mrg 102: };
103:
104: /*
105: * the ops!
106: */
107:
108: /*
109: * uvn_attach
110: *
111: * attach a vnode structure to a VM object. if the vnode is already
112: * attached, then just bump the reference count by one and return the
113: * VM object. if not already attached, attach and return the new VM obj.
114: * the "accessprot" tells the max access the attaching thread wants to
115: * our pages.
116: *
117: * => caller must _not_ already be holding the lock on the uvm_object.
118: * => in fact, nothing should be locked so that we can sleep here.
119: * => note that uvm_object is first thing in vnode structure, so their
120: * pointers are equiv.
121: */
122:
1.8 mrg 123: struct uvm_object *
1.65 thorpej 124: uvn_attach(void *arg, vm_prot_t accessprot)
1.8 mrg 125: {
126: struct vnode *vp = arg;
1.52 chs 127: struct uvm_object *uobj = &vp->v_uobj;
1.8 mrg 128: struct vattr vattr;
1.59 gehenna 129: const struct bdevsw *bdev;
1.37 chs 130: int result;
1.13 thorpej 131: struct partinfo pi;
1.37 chs 132: voff_t used_vnode_size;
1.8 mrg 133: UVMHIST_FUNC("uvn_attach"); UVMHIST_CALLED(maphist);
134:
135: UVMHIST_LOG(maphist, "(vn=0x%x)", arg,0,0,0);
1.37 chs 136: used_vnode_size = (voff_t)0;
1.13 thorpej 137:
1.8 mrg 138: /*
1.52 chs 139: * first get a lock on the uobj.
1.8 mrg 140: */
1.52 chs 141:
142: simple_lock(&uobj->vmobjlock);
143: while (vp->v_flag & VXLOCK) {
144: vp->v_flag |= VXWANT;
1.8 mrg 145: UVMHIST_LOG(maphist, " SLEEPING on blocked vn",0,0,0,0);
1.52 chs 146: UVM_UNLOCK_AND_WAIT(uobj, &uobj->vmobjlock, FALSE,
1.8 mrg 147: "uvn_attach", 0);
1.52 chs 148: simple_lock(&uobj->vmobjlock);
1.8 mrg 149: UVMHIST_LOG(maphist," WOKE UP",0,0,0,0);
150: }
1.1 mrg 151:
1.8 mrg 152: /*
1.18 bouyer 153: * if we're mapping a BLK device, make sure it is a disk.
1.13 thorpej 154: */
1.59 gehenna 155: if (vp->v_type == VBLK) {
156: bdev = bdevsw_lookup(vp->v_rdev);
157: if (bdev == NULL || bdev->d_type != D_DISK) {
158: simple_unlock(&uobj->vmobjlock);
159: UVMHIST_LOG(maphist,"<- done (VBLK not D_DISK!)",
160: 0,0,0,0);
161: return(NULL);
162: }
1.13 thorpej 163: }
1.51 chs 164: KASSERT(vp->v_type == VREG || vp->v_type == VBLK);
1.37 chs 165:
1.13 thorpej 166: /*
1.37 chs 167: * set up our idea of the size
168: * if this hasn't been done already.
1.8 mrg 169: */
1.52 chs 170: if (vp->v_size == VSIZENOTSET) {
1.8 mrg 171:
1.52 chs 172:
173: vp->v_flag |= VXLOCK;
174: simple_unlock(&uobj->vmobjlock); /* drop lock in case we sleep */
1.8 mrg 175: /* XXX: curproc? */
1.13 thorpej 176: if (vp->v_type == VBLK) {
177: /*
178: * We could implement this as a specfs getattr call, but:
179: *
180: * (1) VOP_GETATTR() would get the file system
181: * vnode operation, not the specfs operation.
182: *
183: * (2) All we want is the size, anyhow.
184: */
1.59 gehenna 185: bdev = bdevsw_lookup(vp->v_rdev);
186: if (bdev != NULL) {
187: result = (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART,
1.69 christos 188: (caddr_t)&pi, FREAD, curlwp);
1.59 gehenna 189: } else {
190: result = ENXIO;
191: }
1.13 thorpej 192: if (result == 0) {
193: /* XXX should remember blocksize */
1.37 chs 194: used_vnode_size = (voff_t)pi.disklab->d_secsize *
195: (voff_t)pi.part->p_size;
1.13 thorpej 196: }
197: } else {
1.69.10.1! elad 198: result = VOP_GETATTR(vp, &vattr, curproc->p_cred, curlwp);
1.13 thorpej 199: if (result == 0)
200: used_vnode_size = vattr.va_size;
1.8 mrg 201: }
1.1 mrg 202:
1.8 mrg 203: /* relock object */
1.52 chs 204: simple_lock(&uobj->vmobjlock);
1.37 chs 205:
1.52 chs 206: if (vp->v_flag & VXWANT) {
207: wakeup(vp);
208: }
209: vp->v_flag &= ~(VXLOCK|VXWANT);
1.1 mrg 210:
1.8 mrg 211: if (result != 0) {
1.52 chs 212: simple_unlock(&uobj->vmobjlock);
1.8 mrg 213: UVMHIST_LOG(maphist,"<- done (VOP_GETATTR FAILED!)", 0,0,0,0);
214: return(NULL);
215: }
1.52 chs 216: vp->v_size = used_vnode_size;
1.8 mrg 217:
218: }
219:
1.52 chs 220: simple_unlock(&uobj->vmobjlock);
221: UVMHIST_LOG(maphist,"<- done, refcnt=%d", vp->v_usecount,
1.37 chs 222: 0, 0, 0);
1.52 chs 223: return uobj;
1.1 mrg 224: }
225:
226:
227: /*
228: * uvn_reference
229: *
230: * duplicate a reference to a VM object. Note that the reference
1.49 chs 231: * count must already be at least one (the passed in reference) so
1.1 mrg 232: * there is no chance of the uvn being killed or locked out here.
233: *
1.49 chs 234: * => caller must call with object unlocked.
1.1 mrg 235: * => caller must be using the same accessprot as was used at attach time
236: */
237:
1.66 thorpej 238: static void
1.65 thorpej 239: uvn_reference(struct uvm_object *uobj)
1.1 mrg 240: {
1.37 chs 241: VREF((struct vnode *)uobj);
1.1 mrg 242: }
243:
1.52 chs 244:
1.1 mrg 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: */
1.52 chs 252:
1.66 thorpej 253: static void
1.65 thorpej 254: uvn_detach(struct uvm_object *uobj)
1.8 mrg 255: {
1.37 chs 256: vrele((struct vnode *)uobj);
1.1 mrg 257: }
258:
259: /*
260: * uvn_put: flush page data to backing store.
261: *
1.53 sommerfe 262: * => object must be locked on entry! VOP_PUTPAGES must unlock it.
1.1 mrg 263: * => flags: PGO_SYNCIO -- use sync. I/O
264: * => note: caller must set PG_CLEAN and pmap_clear_modify (if needed)
265: */
266:
1.66 thorpej 267: static int
1.65 thorpej 268: uvn_put(struct uvm_object *uobj, voff_t offlo, voff_t offhi, int flags)
1.1 mrg 269: {
1.37 chs 270: struct vnode *vp = (struct vnode *)uobj;
271: int error;
1.1 mrg 272:
1.53 sommerfe 273: LOCK_ASSERT(simple_lock_held(&vp->v_interlock));
1.54 chs 274: error = VOP_PUTPAGES(vp, offlo, offhi, flags);
1.53 sommerfe 275: LOCK_ASSERT(!simple_lock_held(&vp->v_interlock));
1.48 chs 276: return error;
1.1 mrg 277: }
278:
279:
280: /*
281: * uvn_get: get pages (synchronously) from backing store
282: *
283: * => prefer map unlocked (not required)
284: * => object must be locked! we will _unlock_ it before starting any I/O.
285: * => flags: PGO_ALLPAGES: get all of the pages
286: * PGO_LOCKED: fault data structures are locked
287: * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx]
288: * => NOTE: caller must check for released pages!!
289: */
1.49 chs 290:
1.66 thorpej 291: static int
1.65 thorpej 292: uvn_get(struct uvm_object *uobj, voff_t offset,
293: struct vm_page **pps /* IN/OUT */,
294: int *npagesp /* IN (OUT if PGO_LOCKED)*/,
295: int centeridx, vm_prot_t access_type, int advice, int flags)
1.8 mrg 296: {
1.37 chs 297: struct vnode *vp = (struct vnode *)uobj;
298: int error;
1.67 yamt 299: #if defined(READAHEAD_STATS)
300: int orignpages = *npagesp;
301: #endif /* defined(READAHEAD_STATS) */
302:
1.37 chs 303: UVMHIST_FUNC("uvn_get"); UVMHIST_CALLED(ubchist);
304:
305: UVMHIST_LOG(ubchist, "vp %p off 0x%x", vp, (int)offset, 0,0);
1.68 yamt 306:
307: if ((access_type & VM_PROT_WRITE) == 0 && (flags & PGO_LOCKED) == 0) {
308: simple_unlock(&vp->v_interlock);
309: vn_ra_allocctx(vp);
310: uvm_ra_request(vp->v_ractx, advice, uobj, offset,
311: *npagesp << PAGE_SHIFT);
312: simple_lock(&vp->v_interlock);
313: }
314:
1.37 chs 315: error = VOP_GETPAGES(vp, offset, pps, npagesp, centeridx,
316: access_type, advice, flags);
1.67 yamt 317:
318: #if defined(READAHEAD_STATS)
319: if (((flags & PGO_LOCKED) != 0 && *npagesp > 0) ||
320: ((flags & (PGO_LOCKED|PGO_SYNCIO)) == PGO_SYNCIO && error == 0)) {
321: int i;
322:
323: if ((flags & PGO_LOCKED) == 0) {
324: simple_lock(&uobj->vmobjlock);
325: }
326: for (i = 0; i < orignpages; i++) {
327: struct vm_page *pg = pps[i];
328:
329: if (pg == NULL || pg == PGO_DONTCARE) {
330: continue;
331: }
332: if ((pg->flags & PG_SPECULATIVE) != 0) {
333: pg->flags &= ~PG_SPECULATIVE;
334: uvm_ra_hit.ev_count++;
335: }
336: }
337: if ((flags & PGO_LOCKED) == 0) {
338: simple_unlock(&uobj->vmobjlock);
339: }
340: }
341: #endif /* defined(READAHEAD_STATS) */
342:
1.48 chs 343: return error;
1.37 chs 344: }
1.8 mrg 345:
346:
1.37 chs 347: /*
348: * uvn_findpages:
349: * return the page for the uobj and offset requested, allocating if needed.
350: * => uobj must be locked.
1.52 chs 351: * => returned pages will be BUSY.
1.37 chs 352: */
1.1 mrg 353:
1.58 enami 354: int
1.65 thorpej 355: uvn_findpages(struct uvm_object *uobj, voff_t offset, int *npagesp,
356: struct vm_page **pgs, int flags)
1.37 chs 357: {
1.58 enami 358: int i, count, found, npages, rv;
1.8 mrg 359:
1.58 enami 360: count = found = 0;
1.37 chs 361: npages = *npagesp;
1.52 chs 362: if (flags & UFP_BACKWARD) {
363: for (i = npages - 1; i >= 0; i--, offset -= PAGE_SIZE) {
364: rv = uvn_findpage(uobj, offset, &pgs[i], flags);
1.58 enami 365: if (rv == 0) {
366: if (flags & UFP_DIRTYONLY)
367: break;
368: } else
369: found++;
1.52 chs 370: count++;
371: }
372: } else {
373: for (i = 0; i < npages; i++, offset += PAGE_SIZE) {
374: rv = uvn_findpage(uobj, offset, &pgs[i], flags);
1.58 enami 375: if (rv == 0) {
376: if (flags & UFP_DIRTYONLY)
377: break;
378: } else
379: found++;
1.52 chs 380: count++;
381: }
1.37 chs 382: }
1.52 chs 383: *npagesp = count;
1.58 enami 384: return (found);
1.37 chs 385: }
1.8 mrg 386:
1.66 thorpej 387: static int
1.65 thorpej 388: uvn_findpage(struct uvm_object *uobj, voff_t offset, struct vm_page **pgp,
389: int flags)
1.37 chs 390: {
391: struct vm_page *pg;
1.52 chs 392: boolean_t dirty;
1.37 chs 393: UVMHIST_FUNC("uvn_findpage"); UVMHIST_CALLED(ubchist);
394: UVMHIST_LOG(ubchist, "vp %p off 0x%lx", uobj, offset,0,0);
1.8 mrg 395:
1.37 chs 396: if (*pgp != NULL) {
397: UVMHIST_LOG(ubchist, "dontcare", 0,0,0,0);
398: return 0;
399: }
400: for (;;) {
401: /* look for an existing page */
402: pg = uvm_pagelookup(uobj, offset);
403:
1.52 chs 404: /* nope? allocate one now */
1.37 chs 405: if (pg == NULL) {
406: if (flags & UFP_NOALLOC) {
407: UVMHIST_LOG(ubchist, "noalloc", 0,0,0,0);
408: return 0;
409: }
1.47 chs 410: pg = uvm_pagealloc(uobj, offset, NULL, 0);
1.37 chs 411: if (pg == NULL) {
412: if (flags & UFP_NOWAIT) {
413: UVMHIST_LOG(ubchist, "nowait",0,0,0,0);
414: return 0;
1.8 mrg 415: }
1.37 chs 416: simple_unlock(&uobj->vmobjlock);
417: uvm_wait("uvn_fp1");
1.8 mrg 418: simple_lock(&uobj->vmobjlock);
1.37 chs 419: continue;
1.47 chs 420: }
1.52 chs 421: UVMHIST_LOG(ubchist, "alloced %p", pg,0,0,0);
1.37 chs 422: break;
423: } else if (flags & UFP_NOCACHE) {
424: UVMHIST_LOG(ubchist, "nocache",0,0,0,0);
425: return 0;
1.8 mrg 426: }
427:
1.37 chs 428: /* page is there, see if we need to wait on it */
1.52 chs 429: if ((pg->flags & PG_BUSY) != 0) {
1.37 chs 430: if (flags & UFP_NOWAIT) {
431: UVMHIST_LOG(ubchist, "nowait",0,0,0,0);
432: return 0;
433: }
434: pg->flags |= PG_WANTED;
1.58 enami 435: UVMHIST_LOG(ubchist, "wait %p", pg,0,0,0);
1.37 chs 436: UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
437: "uvn_fp2", 0);
438: simple_lock(&uobj->vmobjlock);
439: continue;
1.8 mrg 440: }
1.49 chs 441:
1.37 chs 442: /* skip PG_RDONLY pages if requested */
443: if ((flags & UFP_NORDONLY) && (pg->flags & PG_RDONLY)) {
444: UVMHIST_LOG(ubchist, "nordonly",0,0,0,0);
445: return 0;
1.8 mrg 446: }
447:
1.52 chs 448: /* stop on clean pages if requested */
449: if (flags & UFP_DIRTYONLY) {
450: dirty = pmap_clear_modify(pg) ||
451: (pg->flags & PG_CLEAN) == 0;
452: pg->flags |= PG_CLEAN;
453: if (!dirty) {
1.58 enami 454: UVMHIST_LOG(ubchist, "dirtonly", 0,0,0,0);
1.52 chs 455: return 0;
456: }
457: }
458:
1.37 chs 459: /* mark the page BUSY and we're done. */
460: pg->flags |= PG_BUSY;
461: UVM_PAGE_OWN(pg, "uvn_findpage");
1.52 chs 462: UVMHIST_LOG(ubchist, "found %p", pg,0,0,0);
1.37 chs 463: break;
1.8 mrg 464: }
1.37 chs 465: *pgp = pg;
466: return 1;
1.1 mrg 467: }
468:
469: /*
1.52 chs 470: * uvm_vnp_setsize: grow or shrink a vnode uobj
1.1 mrg 471: *
472: * grow => just update size value
473: * shrink => toss un-needed pages
474: *
1.49 chs 475: * => we assume that the caller has a reference of some sort to the
1.1 mrg 476: * vnode in question so that it will not be yanked out from under
477: * us.
478: */
479:
1.8 mrg 480: void
1.65 thorpej 481: uvm_vnp_setsize(struct vnode *vp, voff_t newsize)
1.8 mrg 482: {
1.52 chs 483: struct uvm_object *uobj = &vp->v_uobj;
1.46 enami 484: voff_t pgend = round_page(newsize);
1.37 chs 485: UVMHIST_FUNC("uvm_vnp_setsize"); UVMHIST_CALLED(ubchist);
486:
1.52 chs 487: simple_lock(&uobj->vmobjlock);
488: UVMHIST_LOG(ubchist, "vp %p old 0x%x new 0x%x",
489: vp, vp->v_size, newsize, 0);
1.1 mrg 490:
1.8 mrg 491: /*
1.37 chs 492: * now check if the size has changed: if we shrink we had better
493: * toss some pages...
1.8 mrg 494: */
1.1 mrg 495:
1.52 chs 496: if (vp->v_size > pgend && vp->v_size != VSIZENOTSET) {
1.57 chs 497: (void) uvn_put(uobj, pgend, 0, PGO_FREE | PGO_SYNCIO);
1.52 chs 498: } else {
499: simple_unlock(&uobj->vmobjlock);
1.8 mrg 500: }
1.52 chs 501: vp->v_size = newsize;
1.1 mrg 502: }
503:
504: /*
1.37 chs 505: * uvm_vnp_zerorange: set a range of bytes in a file to zero.
1.1 mrg 506: */
507:
1.8 mrg 508: void
1.65 thorpej 509: uvm_vnp_zerorange(struct vnode *vp, off_t off, size_t len)
1.8 mrg 510: {
1.64 chs 511: void *win;
512: int flags;
513:
514: /*
515: * XXXUBC invent kzero() and use it
516: */
1.8 mrg 517:
1.64 chs 518: while (len) {
519: vsize_t bytelen = len;
520:
1.68 yamt 521: win = ubc_alloc(&vp->v_uobj, off, &bytelen, UVM_ADV_NORMAL,
522: UBC_WRITE);
1.64 chs 523: memset(win, 0, bytelen);
524: flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0;
525: ubc_release(win, flags);
526:
527: off += bytelen;
528: len -= bytelen;
529: }
1.1 mrg 530: }
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