/* * Copyright 2000, International Business Machines Corporation and others. * All Rights Reserved. * * This software has been released under the terms of the IBM Public * License. For details, see the LICENSE file in the top-level source * directory or online at http://www.openafs.org/dl/license10.html */ #include #include #ifdef KERNEL # if !defined(UKERNEL) # include "h/types.h" # if !defined(AFS_LINUX26_ENV) # include "h/param.h" # endif # ifdef AFS_AUX_ENV # include "h/mmu.h" # include "h/seg.h" # include "h/sysmacros.h" # include "h/signal.h" # include "h/errno.h" # endif # include "h/time.h" # if defined(AFS_AIX_ENV) || defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV) || defined(AFS_LINUX20_ENV) # include "h/errno.h" # else # if !defined(AFS_SUN5_ENV) && !defined(AFS_LINUX20_ENV) # include "h/kernel.h" # endif # endif # if defined(AFS_SUN5_ENV) || defined(AFS_HPUX_ENV) || defined(AFS_FBSD_ENV) || defined(AFS_DARWIN80_ENV) # include "afs/sysincludes.h" # endif # if !defined(AFS_SGI64_ENV) && !defined(AFS_DARWIN_ENV) && !defined(AFS_OBSD48_ENV) && !defined(AFS_NBSD_ENV) # include "h/user.h" # endif /* AFS_SGI64_ENV */ # include "h/uio.h" # if !defined(AFS_SUN5_ENV) && !defined(AFS_LINUX20_ENV) && !defined(AFS_HPUX110_ENV) # include "h/mbuf.h" # endif # ifndef AFS_LINUX20_ENV # include "netinet/in.h" # endif # else /* !defined(UKERNEL) */ # include "afs/stds.h" # include "afs/sysincludes.h" # endif /* !defined(UKERNEL) */ /* afs_buffer.c */ /* These are needed because afs_prototypes.h is not included here */ struct dcache; struct DirBuffer; extern int DRead(struct dcache *adc, int page, struct DirBuffer *); extern int DNew(struct dcache *adc, int page, struct DirBuffer *); # include "afs/afs_osi.h" # include "afs/dir.h" # ifdef AFS_LINUX20_ENV # include "h/string.h" # endif #else /* KERNEL */ # include # include "dir.h" #endif /* KERNEL */ /* Local static prototypes */ static int FindBlobs(dir_file_t, int); static void AddPage(dir_file_t, int); static void FreeBlobs(dir_file_t, int, int); static int FindItem(dir_file_t, char *, struct DirBuffer *, struct DirBuffer *); /* Find out how many entries are required to store a name. */ int afs_dir_NameBlobs(char *name) { int i; i = strlen(name) + 1; return 1 + ((i + 15) >> 5); } /* Create an entry in a file. Dir is a file representation, while entry is * a string name. */ int afs_dir_Create(dir_file_t dir, char *entry, void *voidfid) { afs_int32 *vfid = (afs_int32 *) voidfid; int blobs, firstelt; int i; struct DirBuffer entrybuf, prevbuf, headerbuf; struct DirEntry *ep; struct DirHeader *dhp; int code; /* check name quality */ if (*entry == 0) return EINVAL; /* First check if file already exists. */ code = FindItem(dir, entry, &prevbuf, &entrybuf); if (code && code != ENOENT) { return code; } if (code == 0) { DRelease(&entrybuf, 0); DRelease(&prevbuf, 0); return EEXIST; } blobs = afs_dir_NameBlobs(entry); /* number of entries required */ firstelt = FindBlobs(dir, blobs); if (firstelt < 0) return EFBIG; /* directory is full */ /* First, we fill in the directory entry. */ if (afs_dir_GetBlob(dir, firstelt, &entrybuf) != 0) return EIO; ep = (struct DirEntry *)entrybuf.data; ep->flag = FFIRST; ep->fid.vnode = htonl(vfid[1]); ep->fid.vunique = htonl(vfid[2]); strcpy(ep->name, entry); /* Now we just have to thread it on the hash table list. */ if (DRead(dir, 0, &headerbuf) != 0) { DRelease(&entrybuf, 1); return EIO; } dhp = (struct DirHeader *)headerbuf.data; i = afs_dir_DirHash(entry); ep->next = dhp->hashTable[i]; dhp->hashTable[i] = htons(firstelt); DRelease(&headerbuf, 1); DRelease(&entrybuf, 1); return 0; } int afs_dir_Length(dir_file_t dir) { int i, ctr; struct DirBuffer headerbuf; struct DirHeader *dhp; if (DRead(dir, 0, &headerbuf) != 0) return 0; dhp = (struct DirHeader *)headerbuf.data; if (dhp->header.pgcount != 0) ctr = ntohs(dhp->header.pgcount); else { /* old style, count the pages */ ctr = 0; for (i = 0; i < MAXPAGES; i++) if (dhp->alloMap[i] != EPP) ctr++; } DRelease(&headerbuf, 0); return ctr * AFS_PAGESIZE; } /* Delete an entry from a directory, including update of all free entry * descriptors. */ int afs_dir_Delete(dir_file_t dir, char *entry) { int nitems, index; struct DirBuffer entrybuf, prevbuf; struct DirEntry *firstitem; unsigned short *previtem; int code; code = FindItem(dir, entry, &prevbuf, &entrybuf); if (code) { return code; } firstitem = (struct DirEntry *)entrybuf.data; previtem = (unsigned short *)prevbuf.data; *previtem = firstitem->next; DRelease(&prevbuf, 1); index = DVOffset(&entrybuf) / 32; nitems = afs_dir_NameBlobs(firstitem->name); /* Clear entire DirEntry and any DirXEntry extensions */ memset(firstitem, 0, nitems * sizeof(*firstitem)); DRelease(&entrybuf, 1); FreeBlobs(dir, index, nitems); return 0; } /* Find a bunch of contiguous entries; at least nblobs in a row. */ static int FindBlobs(dir_file_t dir, int nblobs) { int i, j, k; int failed = 0; struct DirBuffer headerbuf, pagebuf; struct DirHeader *dhp; struct PageHeader *pp; int pgcount; /* read the dir header in first. */ if (DRead(dir, 0, &headerbuf) != 0) return -1; dhp = (struct DirHeader *)headerbuf.data; for (i = 0; i < BIGMAXPAGES; i++) { if (i >= MAXPAGES || dhp->alloMap[i] >= nblobs) { /* if page could contain enough entries */ /* If there are EPP free entries, then the page is not even allocated. */ if (i >= MAXPAGES) { /* this pages exists past the end of the old-style dir */ pgcount = ntohs(dhp->header.pgcount); if (pgcount == 0) { pgcount = MAXPAGES; dhp->header.pgcount = htons(pgcount); } if (i > pgcount - 1) { /* this page is bigger than last allocated page */ AddPage(dir, i); dhp->header.pgcount = htons(i + 1); } } else if (dhp->alloMap[i] == EPP) { /* Add the page to the directory. */ AddPage(dir, i); dhp->alloMap[i] = EPP - 1; dhp->header.pgcount = htons(i + 1); } /* read the page in. */ if (DRead(dir, i, &pagebuf) != 0) { break; } pp = (struct PageHeader *)pagebuf.data; for (j = 0; j <= EPP - nblobs; j++) { failed = 0; for (k = 0; k < nblobs; k++) if ((pp->freebitmap[(j + k) >> 3] >> ((j + k) & 7)) & 1) { failed = 1; break; } if (!failed) break; failed = 1; } if (!failed) { /* Here we have the first index in j. We update the allocation maps * and free up any resources we've got allocated. */ if (i < MAXPAGES) dhp->alloMap[i] -= nblobs; DRelease(&headerbuf, 1); for (k = 0; k < nblobs; k++) pp->freebitmap[(j + k) >> 3] |= 1 << ((j + k) & 7); DRelease(&pagebuf, 1); return j + i * EPP; } DRelease(&pagebuf, 0); /* This dir page is unchanged. */ } } /* If we make it here, the directory is full. */ DRelease(&headerbuf, 1); return -1; } static void AddPage(dir_file_t dir, int pageno) { /* Add a page to a directory. */ int i; struct PageHeader *pp; struct DirBuffer pagebuf; /* Get a new buffer labelled dir,pageno */ DNew(dir, pageno, &pagebuf); pp = (struct PageHeader *)pagebuf.data; pp->tag = htons(1234); if (pageno > 0) pp->pgcount = 0; pp->freecount = EPP - 1; /* The first dude is already allocated */ pp->freebitmap[0] = 0x01; for (i = 1; i < EPP / 8; i++) /* It's a constant */ pp->freebitmap[i] = 0; DRelease(&pagebuf, 1); } /* Free a whole bunch of directory entries. */ static void FreeBlobs(dir_file_t dir, int firstblob, int nblobs) { int i; int page; struct DirBuffer headerbuf, pagehdbuf; struct DirHeader *dhp; struct PageHeader *pp; page = firstblob / EPP; firstblob -= EPP * page; /* convert to page-relative entry */ if (DRead(dir, 0, &headerbuf) != 0) return; dhp = (struct DirHeader *)headerbuf.data; if (page < MAXPAGES) dhp->alloMap[page] += nblobs; DRelease(&headerbuf, 1); if (DRead(dir, page, &pagehdbuf) != 0) return; pp = (struct PageHeader *)pagehdbuf.data; for (i = 0; i < nblobs; i++) pp->freebitmap[(firstblob + i) >> 3] &= ~(1 << ((firstblob + i) & 7)); DRelease(&pagehdbuf, 1); } /*! * Format an empty directory properly. Note that the first 13 entries in a * directory header page are allocated, 1 to the page header, 4 to the * allocation map and 8 to the hash table. * * \param dir pointer to the directory object * \param me fid (vnode+uniq) for new dir * \param parent fid (vnode+uniq) for parent dir * * \retval 0 success * \retval nonzero error code */ int afs_dir_MakeDir(dir_file_t dir, afs_int32 * me, afs_int32 * parent) { int i; struct DirBuffer buffer; struct DirHeader *dhp; int code; DNew(dir, 0, &buffer); dhp = (struct DirHeader *)buffer.data; dhp->header.pgcount = htons(1); dhp->header.tag = htons(1234); dhp->header.freecount = (EPP - DHE - 1); dhp->header.freebitmap[0] = 0xff; dhp->header.freebitmap[1] = 0x1f; for (i = 2; i < EPP / 8; i++) dhp->header.freebitmap[i] = 0; dhp->alloMap[0] = (EPP - DHE - 1); for (i = 1; i < MAXPAGES; i++) dhp->alloMap[i] = EPP; for (i = 0; i < NHASHENT; i++) dhp->hashTable[i] = 0; DRelease(&buffer, 1); code = afs_dir_Create(dir, ".", me); if (code) return code; code = afs_dir_Create(dir, "..", parent); if (code) return code; return 0; } /* Look up a file name in directory. */ int afs_dir_Lookup(dir_file_t dir, char *entry, void *voidfid) { afs_int32 *fid = (afs_int32 *) voidfid; struct DirBuffer firstbuf, prevbuf; struct DirEntry *firstitem; int code; code = FindItem(dir, entry, &prevbuf, &firstbuf); if (code) { return code; } DRelease(&prevbuf, 0); firstitem = (struct DirEntry *)firstbuf.data; fid[1] = ntohl(firstitem->fid.vnode); fid[2] = ntohl(firstitem->fid.vunique); DRelease(&firstbuf, 0); return 0; } /* Look up a file name in directory. */ int afs_dir_LookupOffset(dir_file_t dir, char *entry, void *voidfid, long *offsetp) { afs_int32 *fid = (afs_int32 *) voidfid; struct DirBuffer firstbuf, prevbuf; struct DirEntry *firstitem; int code; code = FindItem(dir, entry, &prevbuf, &firstbuf); if (code) { return code; } DRelease(&prevbuf, 0); firstitem = (struct DirEntry *)firstbuf.data; fid[1] = ntohl(firstitem->fid.vnode); fid[2] = ntohl(firstitem->fid.vunique); if (offsetp) *offsetp = DVOffset(&firstbuf); DRelease(&firstbuf, 0); return 0; } /* * Enumerate the contents of a directory. Break when hook function * returns non 0. */ int afs_dir_EnumerateDir(dir_file_t dir, int (*proc) (void *, char *name, afs_int32 vnode, afs_int32 unique), void *hook) { int i; int num; struct DirBuffer headerbuf, entrybuf; struct DirHeader *dhp; struct DirEntry *ep; int code = 0; int elements; if (DRead(dir, 0, &headerbuf) != 0) return EIO; dhp = (struct DirHeader *)headerbuf.data; for (i = 0; i < NHASHENT; i++) { /* For each hash chain, enumerate everyone on the list. */ num = ntohs(dhp->hashTable[i]); elements = 0; while (num != 0 && elements < BIGMAXPAGES * EPP) { elements++; /* Walk down the hash table list. */ code = afs_dir_GetVerifiedBlob(dir, num, &entrybuf); if (code) goto out; ep = (struct DirEntry *)entrybuf.data; if (!ep) { DRelease(&entrybuf, 0); break; } num = ntohs(ep->next); code = (*proc) (hook, ep->name, ntohl(ep->fid.vnode), ntohl(ep->fid.vunique)); DRelease(&entrybuf, 0); if (code) goto out; } } out: DRelease(&headerbuf, 0); return 0; } int afs_dir_IsEmpty(dir_file_t dir) { /* Enumerate the contents of a directory. */ int i; int num; struct DirBuffer headerbuf, entrybuf; struct DirHeader *dhp; struct DirEntry *ep; int elements; if (DRead(dir, 0, &headerbuf) != 0) return 0; dhp = (struct DirHeader *)headerbuf.data; for (i = 0; i < NHASHENT; i++) { /* For each hash chain, enumerate everyone on the list. */ num = ntohs(dhp->hashTable[i]); elements = 0; while (num != 0 && elements < BIGMAXPAGES * EPP) { elements++; /* Walk down the hash table list. */ if (afs_dir_GetVerifiedBlob(dir, num, &entrybuf) != 0) break; ep = (struct DirEntry *)entrybuf.data; if (strcmp(ep->name, "..") && strcmp(ep->name, ".")) { DRelease(&entrybuf, 0); DRelease(&headerbuf, 0); return 1; } num = ntohs(ep->next); DRelease(&entrybuf, 0); } } DRelease(&headerbuf, 0); return 0; } /* Return a pointer to an entry, given its number. Also return the maximum * size of the entry, which is determined by its position within the directory * page. * * If physerr is supplied by caller, it will be set to: * 0 for logical errors * errno for physical errors */ static int GetBlobWithLimit(dir_file_t dir, afs_int32 blobno, struct DirBuffer *buffer, afs_size_t *maxlen, int *physerr) { afs_size_t pos; int code; *maxlen = 0; memset(buffer, 0, sizeof(struct DirBuffer)); code = DReadWithErrno(dir, blobno >> LEPP, buffer, physerr); if (code) return code; pos = 32 * (blobno & (EPP - 1)); *maxlen = AFS_PAGESIZE - pos - 1; buffer->data = (void *)(((char *)buffer->data) + pos); return 0; } /* * Given an entry's number, return a pointer to that entry. * If physerr is supplied by caller, it will be set to: * 0 for logical errors * errno for physical errors */ int afs_dir_GetBlobWithErrno(dir_file_t dir, afs_int32 blobno, struct DirBuffer *buffer, int *physerr) { afs_size_t maxlen = 0; return GetBlobWithLimit(dir, blobno, buffer, &maxlen, physerr); } /* Given an entries number, return a pointer to that entry */ int afs_dir_GetBlob(dir_file_t dir, afs_int32 blobno, struct DirBuffer *buffer) { afs_size_t maxlen = 0; return GetBlobWithLimit(dir, blobno, buffer, &maxlen, NULL); } /* Return an entry, having verified that the name held within the entry * doesn't overflow off the end of the directory page it is contained * within */ int afs_dir_GetVerifiedBlob(dir_file_t file, afs_int32 blobno, struct DirBuffer *outbuf) { struct DirEntry *dir; struct DirBuffer buffer; afs_size_t maxlen; int code; char *cp; code = GetBlobWithLimit(file, blobno, &buffer, &maxlen, NULL); if (code) return code; dir = (struct DirEntry *)buffer.data; /* A blob is only valid if the name within it is NULL terminated before * the end of the blob's containing page */ for (cp = dir->name; *cp != '\0' && cp < ((char *)dir) + maxlen; cp++); if (*cp != '\0') { DRelease(&buffer, 0); return EIO; } *outbuf = buffer; return 0; } int afs_dir_DirHash(char *string) { /* Hash a string to a number between 0 and NHASHENT. */ unsigned char tc; unsigned int hval; int tval; hval = 0; while ((tc = (*string++))) { hval *= 173; hval += tc; } tval = hval & (NHASHENT - 1); if (tval == 0) return tval; else if (hval >= 1u<<31) tval = NHASHENT - tval; return tval; } /* Find a directory entry, given its name. This entry returns a pointer * to a locked buffer, and a pointer to a locked buffer (in previtem) * referencing the found item (to aid the delete code). If no entry is * found, however, no items are left locked, and a null pointer is * returned instead. */ static int FindItem(dir_file_t dir, char *ename, struct DirBuffer *prevbuf, struct DirBuffer *itembuf ) { int i, code; struct DirBuffer curr, prev; struct DirHeader *dhp; struct DirEntry *tp; int elements; memset(prevbuf, 0, sizeof(struct DirBuffer)); memset(itembuf, 0, sizeof(struct DirBuffer)); code = DRead(dir, 0, &prev); if (code) return code; dhp = (struct DirHeader *)prev.data; i = afs_dir_DirHash(ename); if (dhp->hashTable[i] == 0) { /* no such entry */ code = ENOENT; goto out; } code = afs_dir_GetVerifiedBlob(dir, (u_short) ntohs(dhp->hashTable[i]), &curr); if (code) { goto out; } prev.data = &(dhp->hashTable[i]); elements = 0; /* Detect circular hash chains. Absolute max size of a directory */ while (elements < BIGMAXPAGES * EPP) { elements++; /* Look at each entry on the hash chain */ tp = (struct DirEntry *)curr.data; if (!strcmp(ename, tp->name)) { /* Found it! */ *prevbuf = prev; *itembuf = curr; return 0; } DRelease(&prev, 0); prev = curr; prev.data = &(tp->next); if (tp->next == 0) { /* The end of the line */ code = ENOENT; goto out; } code = afs_dir_GetVerifiedBlob(dir, (u_short) ntohs(tp->next), &curr); if (code) goto out; } /* If we've reached here, we've hit our loop limit. Something is weird with * the directory; maybe a circular hash chain? */ code = EIO; out: DRelease(&prev, 0); return code; } static int FindFid (void *dir, afs_uint32 vnode, afs_uint32 unique, struct DirBuffer *itembuf) { /* Find a directory entry, given the vnode and uniquifier of a object. * This entry returns a pointer to a locked buffer. If no entry is found, * however, no items are left locked, and a null pointer is returned * instead. */ int i, code; unsigned short next; struct DirBuffer curr, header; struct DirHeader *dhp; struct DirEntry *tp; int elements; memset(itembuf, 0, sizeof(struct DirBuffer)); code = DRead(dir, 0, &header); if (code) return code; dhp = (struct DirHeader *)header.data; for (i=0; ihashTable[i] != 0) { code = afs_dir_GetVerifiedBlob(dir, (u_short)ntohs(dhp->hashTable[i]), &curr); if (code) { DRelease(&header, 0); return code; } elements = 0; while(curr.data != NULL && elements < BIGMAXPAGES * EPP) { elements++; tp = (struct DirEntry *)curr.data; if (vnode == ntohl(tp->fid.vnode) && unique == ntohl(tp->fid.vunique)) { DRelease(&header, 0); *itembuf = curr; return 0; } next = tp->next; DRelease(&curr, 0); if (next == 0) break; code = afs_dir_GetVerifiedBlob(dir, (u_short)ntohs(next), &curr); if (code) { DRelease(&header, 0); return code; } } } } DRelease(&header, 0); return ENOENT; } int afs_dir_InverseLookup(void *dir, afs_uint32 vnode, afs_uint32 unique, char *name, afs_uint32 length) { /* Look for the name pointing to given vnode and unique in a directory */ struct DirBuffer entrybuf; struct DirEntry *entry; int code = 0; code = FindFid(dir, vnode, unique, &entrybuf); if (code) { return code; } entry = (struct DirEntry *)entrybuf.data; if (strlen(entry->name) >= length) code = E2BIG; else strcpy(name, entry->name); DRelease(&entrybuf, 0); return code; } /*! * Change an entry fid. * * \param dir * \param entry The entry name. * \param old_fid The old find in MKFid format (host order). * It can be omitted if you don't need a safety check... * \param new_fid The new find in MKFid format (host order). */ int afs_dir_ChangeFid(dir_file_t dir, char *entry, afs_uint32 *old_fid, afs_uint32 *new_fid) { struct DirBuffer prevbuf, entrybuf; struct DirEntry *firstitem; struct MKFid *fid_old = (struct MKFid *) old_fid; struct MKFid *fid_new = (struct MKFid *) new_fid; int code; /* Find entry. */ code = FindItem(dir, entry, &prevbuf, &entrybuf); if (code) { return code; } firstitem = (struct DirEntry *)entrybuf.data; DRelease(&prevbuf, 1); /* Replace fid. */ if (!old_fid || ((htonl(fid_old->vnode) == firstitem->fid.vnode) && (htonl(fid_old->vunique) == firstitem->fid.vunique))) { firstitem->fid.vnode = htonl(fid_new->vnode); firstitem->fid.vunique = htonl(fid_new->vunique); } DRelease(&entrybuf, 1); return 0; }