/* * 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; }
/** * 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; }