Annotation of sys/msdosfs/msdosfs_denode.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: msdosfs_denode.c,v 1.32 2007/06/02 02:04:21 deraadt Exp $ */
2: /* $NetBSD: msdosfs_denode.c,v 1.23 1997/10/17 11:23:58 ws Exp $ */
3:
4: /*-
5: * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6: * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7: * All rights reserved.
8: * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
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: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by TooLs GmbH.
21: * 4. The name of TooLs GmbH may not be used to endorse or promote products
22: * derived from this software without specific prior written permission.
23: *
24: * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34: */
35: /*
36: * Written by Paul Popelka (paulp@uts.amdahl.com)
37: *
38: * You can do anything you want with this software, just don't say you wrote
39: * it, and don't remove this notice.
40: *
41: * This software is provided "as is".
42: *
43: * The author supplies this software to be publicly redistributed on the
44: * understanding that the author is not responsible for the correct
45: * functioning of this software in any circumstances and is not liable for
46: * any damages caused by this software.
47: *
48: * October 1992
49: */
50:
51: #include <sys/param.h>
52: #include <sys/systm.h>
53: #include <sys/mount.h>
54: #include <sys/malloc.h>
55: #include <sys/proc.h>
56: #include <sys/buf.h>
57: #include <sys/vnode.h>
58: #include <sys/kernel.h> /* defines "time" */
59: #include <sys/dirent.h>
60: #include <sys/namei.h>
61:
62: #include <uvm/uvm_extern.h>
63:
64: #include <msdosfs/bpb.h>
65: #include <msdosfs/msdosfsmount.h>
66: #include <msdosfs/direntry.h>
67: #include <msdosfs/denode.h>
68: #include <msdosfs/fat.h>
69:
70: struct denode **dehashtbl;
71: u_long dehash; /* size of hash table - 1 */
72: #define DEHASH(dev, dcl, doff) (((dev) + (dcl) + (doff) / sizeof(struct direntry)) \
73: & dehash)
74:
75: static struct denode *msdosfs_hashget(dev_t, uint32_t, uint32_t);
76: static int msdosfs_hashins(struct denode *);
77: static void msdosfs_hashrem(struct denode *);
78:
79: /*ARGSUSED*/
80: int
81: msdosfs_init(vfsp)
82: struct vfsconf *vfsp;
83: {
84: dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, M_WAITOK, &dehash);
85: return (0);
86: }
87:
88: static struct denode *
89: msdosfs_hashget(dev, dirclust, diroff)
90: dev_t dev;
91: uint32_t dirclust;
92: uint32_t diroff;
93: {
94: struct denode *dep;
95: struct proc *p = curproc; /* XXX */
96:
97: for (;;)
98: for (dep = dehashtbl[DEHASH(dev, dirclust, diroff)];;
99: dep = dep->de_next) {
100: if (dep == NULL)
101: return (NULL);
102: if (dirclust == dep->de_dirclust &&
103: diroff == dep->de_diroffset &&
104: dev == dep->de_dev &&
105: dep->de_refcnt != 0) {
106: struct vnode *vp = DETOV(dep);
107:
108: if (!vget(vp, LK_EXCLUSIVE, p))
109: return (dep);
110: break;
111: }
112: }
113: /* NOTREACHED */
114: }
115:
116: static int
117: msdosfs_hashins(dep)
118: struct denode *dep;
119: {
120: struct denode **depp, *deq;
121:
122: depp = &dehashtbl[DEHASH(dep->de_dev, dep->de_dirclust,
123: dep->de_diroffset)];
124:
125: for (deq = *depp; deq; deq = deq->de_next) {
126: if (dep->de_dirclust == deq->de_dirclust &&
127: dep->de_diroffset == deq->de_diroffset &&
128: dep->de_dev == deq->de_dev &&
129: deq->de_refcnt != 0) {
130: return (EEXIST);
131: }
132: }
133:
134: if ((deq = *depp) != NULL)
135: deq->de_prev = &dep->de_next;
136: dep->de_next = deq;
137: dep->de_prev = depp;
138: *depp = dep;
139: return (0);
140: }
141:
142: static void
143: msdosfs_hashrem(dep)
144: struct denode *dep;
145: {
146: struct denode *deq;
147:
148: if (dep->de_prev == NULL)
149: return;
150:
151: if ((deq = dep->de_next) != NULL)
152: deq->de_prev = dep->de_prev;
153: *dep->de_prev = deq;
154: #ifdef DIAGNOSTIC
155: dep->de_next = NULL;
156: dep->de_prev = NULL;
157: #endif
158: }
159:
160: /*
161: * If deget() succeeds it returns with the gotten denode locked().
162: *
163: * pmp - address of msdosfsmount structure of the filesystem containing
164: * the denode of interest. The pm_dev field and the address of
165: * the msdosfsmount structure are used.
166: * dirclust - which cluster bp contains, if dirclust is 0 (root directory)
167: * diroffset is relative to the beginning of the root directory,
168: * otherwise it is cluster relative.
169: * diroffset - offset past begin of cluster of denode we want
170: * depp - returns the address of the gotten denode.
171: */
172: int
173: deget(pmp, dirclust, diroffset, depp)
174: struct msdosfsmount *pmp; /* so we know the maj/min number */
175: uint32_t dirclust; /* cluster this dir entry came from */
176: uint32_t diroffset; /* index of entry within the cluster */
177: struct denode **depp; /* returns the addr of the gotten denode */
178: {
179: int error;
180: extern int (**msdosfs_vnodeop_p)(void *);
181: struct direntry *direntptr;
182: struct denode *ldep;
183: struct vnode *nvp;
184: struct buf *bp;
185: struct proc *p = curproc; /* XXX */
186:
187: #ifdef MSDOSFS_DEBUG
188: printf("deget(pmp %08x, dirclust %d, diroffset %x, depp %08x)\n",
189: pmp, dirclust, diroffset, depp);
190: #endif
191:
192: /*
193: * On FAT32 filesystems, root is a (more or less) normal
194: * directory
195: */
196: if (FAT32(pmp) && dirclust == MSDOSFSROOT)
197: dirclust = pmp->pm_rootdirblk;
198:
199: /*
200: * See if the denode is in the denode cache. Use the location of
201: * the directory entry to compute the hash value. For subdir use
202: * address of "." entry. For root dir (if not FAT32) use cluster
203: * MSDOSFSROOT, offset MSDOSFSROOT_OFS
204: *
205: * NOTE: The check for de_refcnt > 0 below insures the denode being
206: * examined does not represent an unlinked but still open file.
207: * These files are not to be accessible even when the directory
208: * entry that represented the file happens to be reused while the
209: * deleted file is still open.
210: */
211: retry:
212: ldep = msdosfs_hashget(pmp->pm_dev, dirclust, diroffset);
213: if (ldep) {
214: *depp = ldep;
215: return (0);
216: }
217:
218: /*
219: * Directory entry was not in cache, have to create a vnode and
220: * copy it from the passed disk buffer.
221: */
222: /* getnewvnode() does a VREF() on the vnode */
223: error = getnewvnode(VT_MSDOSFS, pmp->pm_mountp,
224: msdosfs_vnodeop_p, &nvp);
225: if (error) {
226: *depp = 0;
227: return (error);
228: }
229: MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE,
230: M_WAITOK);
231: bzero((caddr_t)ldep, sizeof *ldep);
232: lockinit(&ldep->de_lock, PINOD, "denode", 0, 0);
233: nvp->v_data = ldep;
234: ldep->de_vnode = nvp;
235: ldep->de_flag = 0;
236: ldep->de_devvp = 0;
237: ldep->de_lockf = 0;
238: ldep->de_dev = pmp->pm_dev;
239: ldep->de_dirclust = dirclust;
240: ldep->de_diroffset = diroffset;
241: fc_purge(ldep, 0); /* init the fat cache for this denode */
242:
243: /*
244: * Insert the denode into the hash queue and lock the denode so it
245: * can't be accessed until we've read it in and have done what we
246: * need to it.
247: */
248: vn_lock(nvp, LK_EXCLUSIVE | LK_RETRY, p);
249: error = msdosfs_hashins(ldep);
250:
251: if (error) {
252: vput (nvp);
253:
254: if (error == EEXIST)
255: goto retry;
256:
257: return (error);
258: }
259:
260: ldep->de_pmp = pmp;
261: ldep->de_devvp = pmp->pm_devvp;
262: ldep->de_refcnt = 1;
263: /*
264: * Copy the directory entry into the denode area of the vnode.
265: */
266: if ((dirclust == MSDOSFSROOT
267: || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
268: && diroffset == MSDOSFSROOT_OFS) {
269: /*
270: * Directory entry for the root directory. There isn't one,
271: * so we manufacture one. We should probably rummage
272: * through the root directory and find a label entry (if it
273: * exists), and then use the time and date from that entry
274: * as the time and date for the root denode.
275: */
276: nvp->v_flag |= VROOT; /* should be further down XXX */
277:
278: ldep->de_Attributes = ATTR_DIRECTORY;
279: if (FAT32(pmp))
280: ldep->de_StartCluster = pmp->pm_rootdirblk;
281: /* de_FileSize will be filled in further down */
282: else {
283: ldep->de_StartCluster = MSDOSFSROOT;
284: ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec;
285: }
286: /*
287: * fill in time and date so that dos2unixtime() doesn't
288: * spit up when called from msdosfs_getattr() with root
289: * denode
290: */
291: ldep->de_CTime = 0x0000; /* 00:00:00 */
292: ldep->de_CTimeHundredth = 0;
293: ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
294: | (1 << DD_DAY_SHIFT);
295: /* Jan 1, 1980 */
296: ldep->de_ADate = ldep->de_CDate;
297: ldep->de_MTime = ldep->de_CTime;
298: ldep->de_MDate = ldep->de_CDate;
299: /* leave the other fields as garbage */
300: } else {
301: error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
302: if (error)
303: return (error);
304: DE_INTERNALIZE(ldep, direntptr);
305: brelse(bp);
306: }
307:
308: /*
309: * Fill in a few fields of the vnode and finish filling in the
310: * denode. Then return the address of the found denode.
311: */
312: if (ldep->de_Attributes & ATTR_DIRECTORY) {
313: /*
314: * Since DOS directory entries that describe directories
315: * have 0 in the filesize field, we take this opportunity
316: * to find out the length of the directory and plug it into
317: * the denode structure.
318: */
319: uint32_t size;
320:
321: nvp->v_type = VDIR;
322: if (ldep->de_StartCluster != MSDOSFSROOT) {
323: error = pcbmap(ldep, 0xffff, 0, &size, 0);
324: if (error == E2BIG) {
325: ldep->de_FileSize = de_cn2off(pmp, size);
326: error = 0;
327: } else
328: printf("deget(): pcbmap returned %d\n", error);
329: }
330: } else
331: nvp->v_type = VREG;
332: VREF(ldep->de_devvp);
333: *depp = ldep;
334: return (0);
335: }
336:
337: int
338: deupdat(dep, waitfor)
339: struct denode *dep;
340: int waitfor;
341: {
342: struct buf *bp;
343: struct direntry *dirp;
344: int error;
345: struct timespec ts;
346:
347: if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
348: return (0);
349: getnanotime(&ts);
350: DETIMES(dep, &ts, &ts, &ts);
351: if ((dep->de_flag & DE_MODIFIED) == 0)
352: return (0);
353: dep->de_flag &= ~DE_MODIFIED;
354: if (dep->de_Attributes & ATTR_DIRECTORY)
355: return (0);
356: if (dep->de_refcnt <= 0)
357: return (0);
358: error = readde(dep, &bp, &dirp);
359: if (error)
360: return (error);
361: DE_EXTERNALIZE(dirp, dep);
362: if (waitfor)
363: return (bwrite(bp));
364: else {
365: bdwrite(bp);
366: return (0);
367: }
368: }
369:
370: /*
371: * Truncate the file described by dep to the length specified by length.
372: */
373: int
374: detrunc(dep, length, flags, cred, p)
375: struct denode *dep;
376: uint32_t length;
377: int flags;
378: struct ucred *cred;
379: struct proc *p;
380: {
381: int error;
382: int allerror;
383: int vflags;
384: uint32_t eofentry;
385: uint32_t chaintofree;
386: daddr64_t bn;
387: int boff;
388: int isadir = dep->de_Attributes & ATTR_DIRECTORY;
389: struct buf *bp;
390: struct msdosfsmount *pmp = dep->de_pmp;
391:
392: #ifdef MSDOSFS_DEBUG
393: printf("detrunc(): file %s, length %ld, flags %d\n", dep->de_Name, length, flags);
394: #endif
395:
396: /*
397: * Disallow attempts to truncate the root directory since it is of
398: * fixed size. That's just the way dos filesystems are. We use
399: * the VROOT bit in the vnode because checking for the directory
400: * bit and a startcluster of 0 in the denode is not adequate to
401: * recognize the root directory at this point in a file or
402: * directory's life.
403: */
404: if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
405: printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
406: dep->de_dirclust, dep->de_diroffset);
407: return (EINVAL);
408: }
409:
410: uvm_vnp_setsize(DETOV(dep), length);
411:
412: if (dep->de_FileSize < length)
413: return (deextend(dep, length, cred));
414:
415: /*
416: * If the desired length is 0 then remember the starting cluster of
417: * the file and set the StartCluster field in the directory entry
418: * to 0. If the desired length is not zero, then get the number of
419: * the last cluster in the shortened file. Then get the number of
420: * the first cluster in the part of the file that is to be freed.
421: * Then set the next cluster pointer in the last cluster of the
422: * file to CLUST_EOFE.
423: */
424: if (length == 0) {
425: chaintofree = dep->de_StartCluster;
426: dep->de_StartCluster = 0;
427: eofentry = ~0;
428: } else {
429: error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
430: &eofentry, 0);
431: if (error) {
432: #ifdef MSDOSFS_DEBUG
433: printf("detrunc(): pcbmap fails %d\n", error);
434: #endif
435: return (error);
436: }
437: }
438:
439: fc_purge(dep, de_clcount(pmp, length));
440:
441: /*
442: * If the new length is not a multiple of the cluster size then we
443: * must zero the tail end of the new last cluster in case it
444: * becomes part of the file again because of a seek.
445: */
446: if ((boff = length & pmp->pm_crbomask) != 0) {
447: if (isadir) {
448: bn = cntobn(pmp, eofentry);
449: error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
450: NOCRED, &bp);
451: } else {
452: bn = de_blk(pmp, length);
453: error = bread(DETOV(dep), bn, pmp->pm_bpcluster,
454: NOCRED, &bp);
455: }
456: if (error) {
457: brelse(bp);
458: #ifdef MSDOSFS_DEBUG
459: printf("detrunc(): bread fails %d\n", error);
460: #endif
461: return (error);
462: }
463: uvm_vnp_uncache(DETOV(dep));
464: /*
465: * is this the right place for it?
466: */
467: bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
468: if (flags & IO_SYNC)
469: bwrite(bp);
470: else
471: bdwrite(bp);
472: }
473:
474: /*
475: * Write out the updated directory entry. Even if the update fails
476: * we free the trailing clusters.
477: */
478: dep->de_FileSize = length;
479: if (!isadir)
480: dep->de_flag |= DE_UPDATE|DE_MODIFIED;
481: vflags = (length > 0 ? V_SAVE : 0) | V_SAVEMETA;
482: vinvalbuf(DETOV(dep), vflags, cred, p, 0, 0);
483: allerror = deupdat(dep, 1);
484: #ifdef MSDOSFS_DEBUG
485: printf("detrunc(): allerror %d, eofentry %d\n",
486: allerror, eofentry);
487: #endif
488:
489: /*
490: * If we need to break the cluster chain for the file then do it
491: * now.
492: */
493: if (eofentry != ~0) {
494: error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
495: &chaintofree, CLUST_EOFE);
496: if (error) {
497: #ifdef MSDOSFS_DEBUG
498: printf("detrunc(): fatentry errors %d\n", error);
499: #endif
500: return (error);
501: }
502: fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
503: eofentry);
504: }
505:
506: /*
507: * Now free the clusters removed from the file because of the
508: * truncation.
509: */
510: if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
511: freeclusterchain(pmp, chaintofree);
512:
513: return (allerror);
514: }
515:
516: /*
517: * Extend the file described by dep to length specified by length.
518: */
519: int
520: deextend(dep, length, cred)
521: struct denode *dep;
522: uint32_t length;
523: struct ucred *cred;
524: {
525: struct msdosfsmount *pmp = dep->de_pmp;
526: uint32_t count;
527: int error;
528:
529: /*
530: * The root of a DOS filesystem cannot be extended.
531: */
532: if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
533: return (EINVAL);
534:
535: /*
536: * Directories cannot be extended.
537: */
538: if (dep->de_Attributes & ATTR_DIRECTORY)
539: return (EISDIR);
540:
541: if (length <= dep->de_FileSize)
542: panic("deextend: file too large");
543:
544: /*
545: * Compute the number of clusters to allocate.
546: */
547: count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
548: if (count > 0) {
549: if (count > pmp->pm_freeclustercount)
550: return (ENOSPC);
551: error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
552: if (error) {
553: /* truncate the added clusters away again */
554: (void) detrunc(dep, dep->de_FileSize, 0, cred, NULL);
555: return (error);
556: }
557: }
558:
559: dep->de_FileSize = length;
560: dep->de_flag |= DE_UPDATE|DE_MODIFIED;
561: return (deupdat(dep, 1));
562: }
563:
564: /*
565: * Move a denode to its correct hash queue after the file it represents has
566: * been moved to a new directory.
567: */
568: void
569: reinsert(dep)
570: struct denode *dep;
571: {
572: /*
573: * Fix up the denode cache. If the denode is for a directory,
574: * there is nothing to do since the hash is based on the starting
575: * cluster of the directory file and that hasn't changed. If for a
576: * file the hash is based on the location of the directory entry,
577: * so we must remove it from the cache and re-enter it with the
578: * hash based on the new location of the directory entry.
579: */
580: if (dep->de_Attributes & ATTR_DIRECTORY)
581: return;
582: msdosfs_hashrem(dep);
583: msdosfs_hashins(dep);
584: }
585:
586: int
587: msdosfs_reclaim(v)
588: void *v;
589: {
590: struct vop_reclaim_args *ap = v;
591: struct vnode *vp = ap->a_vp;
592: struct denode *dep = VTODE(vp);
593: #ifdef DIAGNOSTIC
594: extern int prtactive;
595:
596: if (prtactive && vp->v_usecount != 0)
597: vprint("msdosfs_reclaim(): pushing active", vp);
598: #endif
599:
600: #ifdef MSDOSFS_DEBUG
601: printf("msdosfs_reclaim(): dep %08x, file %s, refcnt %d\n",
602: dep, dep->de_Name, dep->de_refcnt);
603: #endif
604:
605: /*
606: * Remove the denode from its hash chain.
607: */
608: msdosfs_hashrem(dep);
609: /*
610: * Purge old data structures associated with the denode.
611: */
612: cache_purge(vp);
613: if (dep->de_devvp) {
614: vrele(dep->de_devvp);
615: dep->de_devvp = 0;
616: }
617: #if 0 /* XXX */
618: dep->de_flag = 0;
619: #endif
620: FREE(dep, M_MSDOSFSNODE);
621: vp->v_data = NULL;
622: return (0);
623: }
624:
625: int
626: msdosfs_inactive(v)
627: void *v;
628: {
629: struct vop_inactive_args *ap = v;
630: struct vnode *vp = ap->a_vp;
631: struct denode *dep = VTODE(vp);
632: struct proc *p = ap->a_p;
633: int error;
634: #ifdef DIAGNOSTIC
635: extern int prtactive;
636:
637: if (prtactive && vp->v_usecount != 0)
638: vprint("msdosfs_inactive(): pushing active", vp);
639: #endif
640:
641: #ifdef MSDOSFS_DEBUG
642: printf("msdosfs_inactive(): dep %08x, de_Name[0] %x\n", dep, dep->de_Name[0]);
643: #endif
644:
645: error = 0;
646:
647: /*
648: * Get rid of denodes related to stale file handles.
649: */
650: if (dep->de_Name[0] == SLOT_DELETED)
651: goto out;
652:
653: /*
654: * If the file has been deleted and it is on a read/write
655: * filesystem, then truncate the file, and mark the directory slot
656: * as empty. (This may not be necessary for the dos filesystem.)
657: */
658: #ifdef MSDOSFS_DEBUG
659: printf("msdosfs_inactive(): dep %08x, refcnt %d, mntflag %x, MNT_RDONLY %x\n",
660: dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
661: #endif
662: if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
663: error = detrunc(dep, (uint32_t)0, 0, NOCRED, NULL);
664: dep->de_Name[0] = SLOT_DELETED;
665: }
666: deupdat(dep, 0);
667:
668: out:
669: VOP_UNLOCK(vp, 0, p);
670: /*
671: * If we are done with the denode, reclaim it
672: * so that it can be reused immediately.
673: */
674: #ifdef MSDOSFS_DEBUG
675: printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount,
676: dep->de_Name[0]);
677: #endif
678: if (dep->de_Name[0] == SLOT_DELETED)
679: vrecycle(vp, p);
680: return (error);
681: }
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