/*!
* \brief Read data from database.
*/
int
udisk_read(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
afs_int32 apos, afs_int32 alen)
{
char *bp;
afs_int32 offset, len, totalLen;
if (atrans->flags & TRDONE)
return UDONE;
totalLen = 0;
while (alen > 0) {
bp = DRead(atrans, afile, apos >> UBIK_LOGPAGESIZE);
if (!bp)
return UEOF;
/* otherwise, min of remaining bytes and end of buffer to user mode */
offset = apos & (UBIK_PAGESIZE - 1);
len = UBIK_PAGESIZE - offset;
if (len > alen)
len = alen;
memcpy(abuffer, bp + offset, len);
abuffer = (char *)abuffer + len;
apos += len;
alen -= len;
totalLen += len;
DRelease(bp, 0);
}
return 0;
}
/*!
* \brief Write data to database, using logs.
*/
int
udisk_write(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
afs_int32 apos, afs_int32 alen)
{
char *bp;
afs_int32 offset, len, totalLen;
struct ubik_trunc *tt;
afs_int32 code;
if (atrans->flags & TRDONE)
return UDONE;
if (atrans->type != UBIK_WRITETRANS)
return UBADTYPE;
/* first write the data to the log */
code = udisk_LogWriteData(atrans->dbase, afile, abuffer, apos, alen);
if (code)
return code;
/* expand any truncations of this file */
tt = FindTrunc(atrans, afile);
if (tt) {
if (tt->length < apos + alen) {
tt->length = apos + alen;
}
}
/* now update vm */
totalLen = 0;
while (alen > 0) {
bp = DRead(atrans, afile, apos >> UBIK_LOGPAGESIZE);
if (!bp) {
bp = DNew(atrans, afile, apos >> UBIK_LOGPAGESIZE);
if (!bp)
return UIOERROR;
memset(bp, 0, UBIK_PAGESIZE);
}
/* otherwise, min of remaining bytes and end of buffer to user mode */
offset = apos & (UBIK_PAGESIZE - 1);
len = UBIK_PAGESIZE - offset;
if (len > alen)
len = alen;
memcpy(bp + offset, abuffer, len);
abuffer = (char *)abuffer + len;
apos += len;
alen -= len;
totalLen += len;
DRelease(bp, 1); /* buffer modified */
}
/**
* 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;
}
/**
* Salvage a directory object.
*
* @param[in] fromFile fid of original, currently suspect directory object
* @param[in] toFile fid where salvager will place new, fixed directory
* @param[in] vn vnode of currently suspect directory
* @param[in] vu uniquifier of currently suspect directory
* @param[in] pvn vnode of parent directory
* @param[in] pvu uniquifier of parent directory
*
* @return operation status
* @retval 0 success
*/
int
DirSalvage(void *fromFile, void *toFile, afs_int32 vn, afs_int32 vu,
afs_int32 pvn, afs_int32 pvu)
{
/* First do a MakeDir on the target. */
afs_int32 dot[3], dotdot[3], lfid[3], code, usedPages;
char tname[256];
register int i;
register char *tp;
struct DirHeader *dhp;
struct DirEntry *ep;
int entry;
memset(dot, 0, sizeof(dot));
memset(dotdot, 0, sizeof(dotdot));
dot[1] = vn;
dot[2] = vu;
dotdot[1] = pvn;
dotdot[2] = pvu;
MakeDir(toFile, dot, dotdot); /* Returns no error code. */
/* Find out how many pages are valid, using stupid heuristic since DRead
* never returns null.
*/
dhp = (struct DirHeader *)DRead(fromFile, 0);
if (!dhp) {
printf("Failed to read first page of fromDir!\n");
/* if DErrno != 0, then our call failed and we should let our
* caller know that there's something wrong with the new dir. If not,
* then we return here anyway, with an empty, but at least good, directory.
*/
return DErrno;
}
usedPages = ComputeUsedPages(dhp);
/* Finally, enumerate all the entries, doing a create on them. */
for (i = 0; i < NHASHENT; i++) {
entry = ntohs(dhp->hashTable[i]);
while (1) {
if (!entry)
break;
if (entry < 0 || entry >= usedPages * EPP) {
printf
("Warning: bogus hash table entry encountered, ignoring.\n");
break;
}
DErrno = 0;
ep = GetBlob(fromFile, entry);
if (!ep) {
if (DErrno) {
printf
("can't continue down hash chain (entry %d, errno %d)\n",
entry, DErrno);
DRelease(dhp, 0);
return DErrno;
}
printf
("Warning: bogus hash chain encountered, switching to next.\n");
break;
}
strncpy(tname, ep->name, MAXENAME);
tname[MAXENAME - 1] = '\000'; /* just in case */
tp = tname;
entry = ntohs(ep->next);
if ((strcmp(tp, ".") != 0) && (strcmp(tp, "..") != 0)) {
lfid[1] = ntohl(ep->fid.vnode);
lfid[2] = ntohl(ep->fid.vunique);
code = Create(toFile, tname, lfid);
if (code) {
printf
("Create of %s returned code %d, skipping to next hash chain.\n",
tname, code);
DRelease(ep, 0);
break;
}
}
DRelease(ep, 0);
}
}
/* Clean up things. */
DRelease(dhp, 0);
return 0;
}
