コード例 #1
0
ファイル: afs_dynroot.c プロジェクト: stevenjenkins/openafs
/*
 * Add directory entry by given name to a directory.  Assumes the
 * caller has allocated the directory to be large enough to hold
 * the necessary entry.
 */
static void
afs_dynroot_addDirEnt(struct DirHeader *dirHeader, int *curPageP,
		      int *curChunkP, char *name, int vnode)
{
    char *dirBase = (char *)dirHeader;
    struct PageHeader *pageHeader;
    struct DirEntry *dirEntry;
    int sizeOfEntry, i, t1, t2;
    int curPage = *curPageP;
    int curChunk = *curChunkP;
    int didNewPage = 0;

    /*
     * Check if we need to flip pages..  If so, init the new page.
     */
    sizeOfEntry = afs_dir_NameBlobs(name);
    if (curChunk + sizeOfEntry > EPP) {
	curPage++;
	curChunk = 1;
	didNewPage = 1;
    }

    pageHeader = (struct PageHeader *)(dirBase + curPage * AFS_PAGESIZE);
    if (didNewPage) {
	pageHeader->pgcount = 0;
	pageHeader->tag = htons(1234);
	pageHeader->freecount = 0;
	pageHeader->freebitmap[0] = 0x01;
	for (i = 1; i < EPP / 8; i++)
	    pageHeader->freebitmap[i] = 0;

	dirHeader->alloMap[curPage] = EPP - 1;
    }

    dirEntry = (struct DirEntry *)(pageHeader + curChunk);
    dirEntry->flag = 1;
    dirEntry->length = 0;
    dirEntry->next = 0;
    dirEntry->fid.vnode = htonl(vnode);
    dirEntry->fid.vunique = htonl(1);
    strcpy(dirEntry->name, name);

    for (i = curChunk; i < curChunk + sizeOfEntry; i++) {
	t1 = i / 8;
	t2 = i % 8;
	pageHeader->freebitmap[t1] |= (1 << t2);
    }

    /*
     * Add the new entry to the correct hash chain.
     */
    i = DirHash(name);
    dirEntry->next = dirHeader->hashTable[i];
    dirHeader->hashTable[i] = htons(curPage * EPP + curChunk);

    curChunk += sizeOfEntry;
    dirHeader->alloMap[curPage] -= sizeOfEntry;

    *curPageP = curPage;
    *curChunkP = curChunk;
}
コード例 #2
0
ファイル: salvage.c プロジェクト: mattjsm/openafs-netbsd5
/**
 * check whether a directory object is ok.
 *
 * @param[in] file  opaque pointer to directory object fid
 *
 * @return operation status
 *    @retval 1 dir is fine, or something went wrong checking
 *    @retval 0 we *know* that the dir is bad
 */
int
DirOK(void *file)
{
    struct DirHeader *dhp;
    struct PageHeader *pp;
    struct DirEntry *ep;
    int i, j, k, up;
    int havedot = 0, havedotdot = 0;
    int usedPages, count, entry;
    char eaMap[BIGMAXPAGES * EPP / 8];	/* Change eaSize initialization below, too. */
    int eaSize;
    afs_int32 entcount, maxents;
    unsigned short ne;

    eaSize = BIGMAXPAGES * EPP / 8;

    /* Read the directory header */
    dhp = (struct DirHeader *)DRead(file, 0);
    if (!dhp) {
	/* if DErrno is 0, then we know that the read worked, but was short,
	 * and the damage is permanent.  Otherwise, we got an I/O or programming
	 * error.  Claim the dir is OK, but log something.
	 */
	if (DErrno != 0) {
	    printf("Could not read first page in directory (%d)\n", DErrno);
	    Die("dirok1");
	    return 1;
	}
	printf("First page in directory does not exist.\n");
	return 0;
    }

    /* Check magic number for first page */
    if (dhp->header.tag != htons(1234)) {
	printf("Bad first pageheader magic number.\n");
	DRelease(dhp, 0);
	return 0;
    }

    /* Verify that the number of free entries in each directory page
     * is within range (0-EPP). Also ensure directory is contiguous:
     * Once the first alloMap entry with EPP free entries is found,
     * the rest should match.
     */
    up = 0;			/* count of used pages if total pages < MAXPAGES */
    k = 0;			/* found last page */
    for (i = 0; i < MAXPAGES; i++) {
	j = dhp->alloMap[i];

	/* Check if in range */
	if (i == 0) {
	    if ((j < 0) || (j > EPP - (13 + 2))) {
		/* First page's dirheader uses 13 entries and at least
		 * two must exist for "." and ".."
		 */
		printf("The dir header alloc map for page %d is bad.\n", i);
		DRelease(dhp, 0);
		return 0;
	    }
	} else {
	    if ((j < 0) || (j > EPP)) {
		printf("The dir header alloc map for page %d is bad.\n", i);
		DRelease(dhp, 0);
		return 0;
	    }
	}

	/* Check if contiguous */
	if (k) {		/* last page found */
	    if (j != EPP) {	/* remaining entries must be EPP */
		printf
		    ("A partially-full page occurs in slot %d, after the dir end.\n",
		     i);
		DRelease(dhp, 0);
		return 0;
	    }
	} else if (j == EPP) {	/* is this the last page */
	    k = 1;		/* yes */
	} else {		/* a used page */
	    up++;		/* keep count */
	}
    }

    /* Compute number of used directory pages and max entries in all 
     ** those pages, the value of 'up' must be less than pgcount. The above
     ** loop only checks the first MAXPAGES in a directory. An alloMap does
     ** not exists for pages between MAXPAGES and BIGMAXPAGES */
    usedPages = ComputeUsedPages(dhp);
    if (usedPages < up) {
	printf
	    ("Count of used directory pages does not match count in directory header\n");
	DRelease(dhp, 0);
	return 0;
    }

    /* For each directory page, check the magic number in each page
     * header, and check that number of free entries (from freebitmap)
     * matches the count in the alloMap from directory header.
     */
    for (i = 0; i < usedPages; i++) {
	/* Read the page header */
	pp = (struct PageHeader *)DRead(file, i);
	if (!pp) {
	    DRelease(dhp, 0);
	    if (DErrno != 0) {
		/* couldn't read page, but not because it wasn't there permanently */
		printf("Failed to read dir page %d (errno %d)\n", i, DErrno);
		Die("dirok2");
		return 1;
	    }
	    printf("Directory shorter than alloMap indicates (page %d)\n", i);
	    return 0;
	}

	/* check the tag field */
	if (pp->tag != htons(1234)) {
	    printf("Directory page %d has a bad magic number.\n", i);
	    DRelease(pp, 0);
	    DRelease(dhp, 0);
	    return 0;
	}

	/* Count the number of entries allocated in this single
	 * directory page using the freebitmap in the page header.
	 */
	count = 0;
	for (j = 0; j < EPP / 8; j++) {
	    k = pp->freebitmap[j];
	    if (k & 0x80)
		count++;
	    if (k & 0x40)
		count++;
	    if (k & 0x20)
		count++;
	    if (k & 0x10)
		count++;
	    if (k & 0x08)
		count++;
	    if (k & 0x04)
		count++;
	    if (k & 0x02)
		count++;
	    if (k & 0x01)
		count++;
	}
	count = EPP - count;	/* Change to count of free entries */

	/* Now check that the count of free entries matches the count in the alloMap */
	if ((i < MAXPAGES) && ((count & 0xff) != (dhp->alloMap[i] & 0xff))) {
	    printf
		("Header alloMap count doesn't match count in freebitmap for page %d.\n",
		 i);
	    DRelease(pp, 0);
	    DRelease(dhp, 0);
	    return 0;
	}

	DRelease(pp, 0);
    }

    /* Initialize the in-memory freebit map for all pages. */
    for (i = 0; i < eaSize; i++) {
	eaMap[i] = 0;
	if (i < usedPages * (EPP / 8)) {
	    if (i == 0) {
		eaMap[i] = 0xff;	/* A dir header uses first 13 entries */
	    } else if (i == 1) {
		eaMap[i] = 0x1f;	/* A dir header uses first 13 entries */
	    } else if ((i % 8) == 0) {
		eaMap[i] = 0x01;	/* A page header uses only first entry */
	    }
	}
    }
    maxents = usedPages * EPP;

    /* Walk down all the hash lists, ensuring that each flag field has FFIRST
     * in it.  Mark the appropriate bits in the in-memory freebit map.
     * Check that the name is in the right hash bucket.
     * Also check for loops in the hash chain by counting the entries.
     */
    for (entcount = 0, i = 0; i < NHASHENT; i++) {
	for (entry = ntohs(dhp->hashTable[i]); entry; entry = ne) {
	    /* Verify that the entry is within range */
	    if (entry < 0 || entry >= maxents) {
		printf("Out-of-range hash id %d in chain %d.\n", entry, i);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* Read the directory entry */
	    DErrno = 0;
	    ep = GetBlob(file, entry);
	    if (!ep) {
		if (DErrno != 0) {
		    /* something went wrong reading the page, but it wasn't
		     * really something wrong with the dir that we can fix.
		     */
		    printf("Could not get dir blob %d (errno %d)\n", entry,
			   DErrno);
		    DRelease(dhp, 0);
		    Die("dirok3");
		}
		printf("Invalid hash id %d in chain %d.\n", entry, i);
		DRelease(dhp, 0);
		return 0;
	    }
	    ne = ntohs(ep->next);

	    /* There can't be more than maxents entries */
	    if (++entcount >= maxents) {
		printf("Directory's hash chain %d is circular.\n", i);
		DRelease(ep, 0);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* A null name is no good */
	    if (ep->name[0] == '\000') {
		printf("Dir entry %x in chain %d has bogus (null) name.\n",
		       (intptr_t)ep, i);
		DRelease(ep, 0);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* The entry flag better be FFIRST */
	    if (ep->flag != FFIRST) {
		printf("Dir entry %x in chain %d has bogus flag field.\n", (intptr_t)ep,
		       i);
		DRelease(ep, 0);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* Check the size of the name */
	    j = strlen(ep->name);
	    if (j >= MAXENAME) {	/* MAXENAME counts the null */
		printf("Dir entry %x in chain %d has too-long name.\n", (intptr_t)ep,
		       i);
		DRelease(ep, 0);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* The name used up k directory entries, set the bit in our in-memory
	     * freebitmap for each entry used by the name.
	     */
	    k = NameBlobs(ep->name);
	    for (j = 0; j < k; j++) {
		eaMap[(entry + j) >> 3] |= (1 << ((entry + j) & 7));
	    }

	    /* Hash the name and make sure it is in the correct name hash */
	    if ((j = DirHash(ep->name)) != i) {
		printf
		    ("Dir entry %x should be in hash bucket %d but IS in %d.\n",
		     (intptr_t)ep, j, i);
		DRelease(ep, 0);
		DRelease(dhp, 0);
		return 0;
	    }

	    /* Check that if this is entry 13 (the 1st entry), then name must be "." */
	    if (entry == 13) {
		if (strcmp(ep->name, ".") == 0) {
		    havedot = 1;
		} else {
		    printf
			("Dir entry %x, index 13 has name '%s' should be '.'\n",
			 (intptr_t)ep, ep->name);
		    DRelease(ep, 0);
		    DRelease(dhp, 0);
		    return 0;
		}
	    }

	    /* Check that if this is entry 14 (the 2nd entry), then name must be ".." */
	    if (entry == 14) {
		if (strcmp(ep->name, "..") == 0) {
		    havedotdot = 1;
		} else {
		    printf
			("Dir entry %x, index 14 has name '%s' should be '..'\n",
			 (intptr_t)ep, ep->name);
		    DRelease(ep, 0);
		    DRelease(dhp, 0);
		    return 0;
		}
	    }

	    /* CHECK FOR DUPLICATE NAMES? */

	    DRelease(ep, 0);
	}
    }

    /* Verify that we found '.' and '..' in the correct place */
    if (!havedot || !havedotdot) {
	printf
	    ("Directory entry '.' or '..' does not exist or is in the wrong index.\n");
	DRelease(dhp, 0);
	return 0;
    }

    /* The in-memory freebit map has been computed.  Check that it
     * matches the one in the page header.
     * Note that if this matches, alloMap has already been checked against it.
     */
    for (i = 0; i < usedPages; i++) {
	pp = DRead(file, i);
	if (!pp) {
	    printf
		("Failed on second attempt to read dir page %d (errno %d)\n",
		 i, DErrno);
	    DRelease(dhp, 0);
	    /* if DErrno is 0, then the dir is really bad, and we return dir *not* OK.
	     * otherwise, we want to return true (1), meaning the dir isn't known
	     * to be bad (we can't tell, since I/Os are failing.
	     */
	    if (DErrno != 0)
		Die("dirok4");
	    else
		return 0;	/* dir is really shorter */
	}

	count = i * (EPP / 8);
	for (j = 0; j < EPP / 8; j++) {
	    if (eaMap[count + j] != pp->freebitmap[j]) {
		printf
		    ("Entry freebitmap error, page %d, map offset %d, %x should be %x.\n",
		     i, j, pp->freebitmap[j], eaMap[count + j]);
		DRelease(pp, 0);
		DRelease(dhp, 0);
		return 0;
	    }
	}

	DRelease(pp, 0);
    }

    /* Finally cleanup and return. */
    DRelease(dhp, 0);
    return 1;
}