-/* vfs_lookup.c 6.5 84/01/04 */
-
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/inode.h"
-#include "../h/fs.h"
-#include "../h/mount.h"
-#include "../h/dir.h"
-#include "../h/user.h"
-#include "../h/buf.h"
-#include "../h/conf.h"
-#include "../h/uio.h"
-#include "../h/nami.h"
-#include "../h/kernel.h"
-
-struct buf *blkatoff();
-int dirchk = 0;
-
/*
- * Structures associated with name cacheing.
+ * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley. The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * @(#)vfs_lookup.c 7.11 (Berkeley) %G%
*/
-#define NCHHASH 32 /* size of hash table */
-#if ((NCHHASH)&((NCHHASH)-1)) != 0
-#define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) % (NCHHASH))
-#else
-#define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) & ((NCHHASH)-1))
+#include "param.h"
+#include "time.h"
+#include "namei.h"
+#include "vnode.h"
+#include "mount.h"
+#include "errno.h"
+#include "malloc.h"
+
+#ifdef KTRACE
+#include "user.h"
+#include "proc.h"
+#include "ktrace.h"
#endif
-union nchash {
- union nchash *nch_head[2];
- struct nch *nch_chain[2];
-} nchash[NCHHASH];
-#define nch_forw nch_chain[0]
-#define nch_back nch_chain[1]
-
-struct nch *nchhead, **nchtail; /* LRU chain pointers */
-struct nchstats nchstats; /* cache effectiveness statistics */
-
/*
- * Convert a pathname into a pointer to a locked inode,
- * with side effects usable in creating and removing files.
+ * Convert a pathname into a pointer to a locked inode.
* This is a very central and rather complicated routine.
*
- * The func argument gives the routine which returns successive
- * characters of the name to be translated.
+ * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
+ * whether the name is to be looked up, created, renamed, or deleted.
+ * When CREATE, RENAME, or DELETE is specified, information usable in
+ * creating, renaming, or deleting a directory entry may be calculated.
+ * If flag has LOCKPARENT or'ed into it and the target of the pathname
+ * exists, namei returns both the target and its parent directory locked.
+ * When creating or renaming and LOCKPARENT is specified, the target may not
+ * be ".". When deleting and LOCKPARENT is specified, the target may be ".".
*
- * The flag argument is (LOOKUP, CREATE, DELETE) depending on whether
- * the name is to be (looked up, created, deleted). If flag has
- * LOCKPARENT or'ed into it and the target of the pathname exists,
- * namei returns both the target and its parent directory locked.
- * If the file system is not maintained in a strict tree hierarchy,
- * this can result in a deadlock situation. When creating and
- * LOCKPARENT is specified, the target may not be ".". When deleting
- * and LOCKPARENT is specified, the target may be ".", but the caller
- * must check to insure it does an irele and iput instead of two iputs.
- *
- * The follow argument is 1 when symbolic links are to be followed
+ * The FOLLOW flag is set when symbolic links are to be followed
* when they occur at the end of the name translation process.
+ * Symbolic links are always followed for all other pathname
+ * components other than the last.
*
- * Name caching works as follows:
- *
- * names found by directory scans are retained in a cache
- * for future reference. It is managed LRU, so frequently
- * used names will hang around. Cache is indexed by hash value
- * obtained from (ino,dev,name) where ino & dev refer to the
- * directory containing name.
- *
- * For simplicity (and economy of storage), names longer than
- * some (small) maximum length are not cached, they occur
- * infrequently in any case, and are almost never of interest.
- *
- * Upon reaching the last segment of a path, if the reference
- * is for DELETE, or NOCACHE is set (rewrite), and the
- * name is located in the cache, it will be dropped.
- *
- * We must be sure never to enter the name ".." into the cache
- * because of the extremely kludgey way that rename() alters
- * ".." in a situation like
- * mv a/x b/x
- * where x is a directory, and x/.. is the ".." in question.
+ * The segflg defines whether the name is to be copied from user
+ * space or kernel space.
*
* Overall outline of namei:
*
* copy in name
* get starting directory
* dirloop:
- * check accessibility of directory
- * dirloop2:
- * copy next component of name to u.u_dent
+ * copy next component of name to ndp->ni_dent
* handle degenerate case where name is null string
- * look for name in cache, if found, then if at end of path
- * and deleting or creating, drop it, else to haveino
- * search for name in directory, to found or notfound
- * notfound:
- * if creating, return locked directory, leaving info on avail. slots
- * else return error
- * found:
- * if at end of path and deleting, return information to allow delete
- * if at end of path and rewriting (create and LOCKPARENT), lock target
- * inode and return info to allow rewrite
- * if .. and on mounted filesys, look in mount table for parent
- * if not at end, if neither creating nor deleting, add name to cache
- * haveino:
+ * if .. and on mounted filesys, find parent
+ * call lookup routine for next component name
+ * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set
+ * component vnode returned in ni_vp (if it exists), locked.
* if symbolic link, massage name in buffer and continue at dirloop
+ * if result inode is mounted on, find mounted on vnode
* if more components of name, do next level at dirloop
- * return the answer as locked inode
+ * return the answer in ni_vp as locked vnode;
+ * if LOCKPARENT set, return locked parent in ni_dvp
*
- * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode,
- * but unlocked.
+ * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent vnode unlocked.
*/
-struct inode *
-namei(func, flag, follow)
- int (*func)(), flag, follow;
+namei(ndp)
+ register struct nameidata *ndp;
{
register char *cp; /* pointer into pathname argument */
-/* these variables refer to things which must be freed or unlocked */
- register struct inode *dp = 0; /* the directory we are searching */
- register struct nch *ncp; /* cache slot for entry */
- register struct fs *fs; /* file system that directory is in */
- register struct buf *bp = 0; /* a buffer of directory entries */
- register struct direct *ep; /* the current directory entry */
- int entryoffsetinblock; /* offset of ep in bp's buffer */
- register struct buf *nbp; /* buffer storing path name argument */
-/* these variables hold information about the search for a slot */
- enum {NONE, COMPACT, FOUND} slotstatus;
- int slotoffset = -1; /* offset of area with free space */
- int slotsize; /* size of area at slotoffset */
- int slotfreespace; /* amount of space free in slot */
- int slotneeded; /* size of the entry we're seeking */
-/* */
- int numdirpasses; /* strategy for directory search */
- int endsearch; /* offset to end directory search */
- int prevoff; /* u.u_offset of previous entry */
- int nlink = 0; /* number of symbolic links taken */
- struct inode *pdp; /* saved dp during symlink work */
- int i;
- int lockparent;
- int docache;
- unsigned hash; /* value of name hash for entry */
- union nchash *nhp; /* cache chain head for entry */
- int isdotdot; /* != 0 if current name is ".." */
+ register struct vnode *dp = 0; /* the directory we are searching */
+ register int i; /* Temp counter */
+ struct vnode *tdp; /* saved dp */
+ struct mount *mp; /* mount table entry */
+ int docache; /* == 0 do not cache last component */
+ int flag; /* LOOKUP, CREATE, RENAME or DELETE */
+ int wantparent; /* 1 => wantparent or lockparent flag */
+ int lockparent; /* 1 => lockparent flag */
+ int error = 0;
- lockparent = flag & LOCKPARENT;
- docache = (flag & NOCACHE) ^ NOCACHE;
- flag &= ~(LOCKPARENT|NOCACHE);
- if (flag == DELETE)
+ flag = ndp->ni_nameiop & OPFLAG;
+ wantparent = ndp->ni_nameiop & (LOCKPARENT|WANTPARENT);
+ lockparent = ndp->ni_nameiop & LOCKPARENT;
+ docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE;
+ if (flag == DELETE || wantparent)
docache = 0;
/*
* Get a buffer for the name to be translated, and copy the
* name into the buffer.
*/
- nbp = geteblk(MAXPATHLEN);
- for (cp = nbp->b_un.b_addr; *cp = (*func)(); ) {
- if ((*cp&0377) == ('/'|0200) || (*cp&0200) && flag != LOOKUP) {
- u.u_error = EPERM;
- goto bad;
- }
- cp++;
- if (cp >= nbp->b_un.b_addr + MAXPATHLEN) {
- u.u_error = ENOENT;
- goto bad;
- }
+ MALLOC(ndp->ni_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
+ if (ndp->ni_segflg == UIO_SYSSPACE)
+ error = copystr(ndp->ni_dirp, ndp->ni_pnbuf, MAXPATHLEN,
+ &ndp->ni_pathlen);
+ else
+ error = copyinstr(ndp->ni_dirp, ndp->ni_pnbuf, MAXPATHLEN,
+ &ndp->ni_pathlen);
+ if (error) {
+ free(ndp->ni_pnbuf, M_NAMEI);
+ ndp->ni_vp = NULL;
+ return (error);
}
- if (u.u_error)
- goto bad;
+ ndp->ni_ptr = ndp->ni_pnbuf;
+ ndp->ni_loopcnt = 0;
+ dp = ndp->ni_cdir;
+ dp->v_count++;
+#ifdef KTRACE
+ if (KTRPOINT(u.u_procp, KTR_NAMEI))
+ ktrnamei(u.u_procp->p_tracep, ndp->ni_pnbuf);
+#endif
+start:
/*
* Get starting directory.
+ * Done at start of translation and after symbolic link.
*/
- cp = nbp->b_un.b_addr;
- if (*cp == '/') {
- while (*cp == '/')
- cp++;
- if ((dp = u.u_rdir) == NULL)
+ if (*ndp->ni_ptr == '/') {
+ vrele(dp);
+ while (*ndp->ni_ptr == '/') {
+ ndp->ni_ptr++;
+ ndp->ni_pathlen--;
+ }
+ if ((dp = ndp->ni_rdir) == NULL)
dp = rootdir;
- } else
- dp = u.u_cdir;
- fs = dp->i_fs;
- ilock(dp);
- dp->i_count++;
- u.u_pdir = (struct inode *)0xc0000000; /* illegal */
+ dp->v_count++;
+ }
+ VOP_LOCK(dp);
+ ndp->ni_endoff = 0;
/*
* We come to dirloop to search a new directory.
- * The directory must be locked so that it can be
- * iput, and fs must be already set to dp->i_fs.
*/
dirloop:
/*
- * Check accessiblity of directory.
+ * Copy next component of name to ndp->ni_dent.
+ * XXX kern_exec looks at d_name
+ * ??? The ni_hash value may be useful for vfs_cache
+ * XXX There must be the last component of the filename left
+ * somewhere accessible via. ndp for NFS (and any other stateless file
+ * systems) in case they are doing a CREATE. The "Towards a..." noted
+ * that ni_ptr would be left pointing to the last component, but since
+ * the ni_pnbuf gets free'd, that is not a good idea.
*/
- if ((dp->i_mode&IFMT) != IFDIR) {
- u.u_error = ENOTDIR;
- goto bad;
+#ifdef notdef
+ for (cp = ndp->ni_ptr; *cp != 0 && *cp != '/'; cp++) {
+ if ((*cp & 0200) == 0)
+ continue;
+ if ((*cp&0377) == ('/'|0200) || flag != DELETE) {
+ error = EINVAL;
+ goto bad;
+ }
}
- if (access(dp, IEXEC))
+ ndp->ni_namelen = cp - ndp->ni_ptr;
+ if (ndp->ni_namelen >= MAXNAMLEN) {
+ error = ENAMETOOLONG;
goto bad;
-
-dirloop2:
- /*
- * Copy next component of name to u.u_dent.
- */
- hash = 0;
- for (i = 0; *cp != 0 && *cp != '/'; cp++) {
+ }
+ ndp->ni_pathlen -= ndp->ni_namelen;
+#ifdef NAMEI_DIAGNOSTIC
+ { char c = *cp;
+ *cp = '\0';
+ printf("{%s}: ", ndp->ni_ptr);
+ *cp = c; }
+#endif
+#else fornow
+ ndp->ni_hash = 0;
+ for (cp = ndp->ni_ptr, i = 0; *cp != 0 && *cp != '/'; cp++) {
if (i >= MAXNAMLEN) {
- u.u_error = ENOENT;
+ error = ENAMETOOLONG;
goto bad;
}
- u.u_dent.d_name[i++] = *cp;
- hash += (unsigned char)*cp * i;
+ if (*cp & 0200)
+ if ((*cp&0377) == ('/'|0200) || flag != DELETE) {
+ error = EINVAL;
+ goto bad;
+ }
+ ndp->ni_dent.d_name[i++] = *cp;
+ ndp->ni_hash += (unsigned char)*cp * i;
}
- u.u_dent.d_namlen = i;
- u.u_dent.d_name[i] = 0;
+ ndp->ni_namelen = i;
+ ndp->ni_dent.d_namlen = i;
+ ndp->ni_dent.d_name[i] = '\0';
+ ndp->ni_pathlen -= i;
+#ifdef NAMEI_DIAGNOSTIC
+ printf("{%s}: ", ndp->ni_dent.d_name);
+#endif
+#endif fornow
+ ndp->ni_next = cp;
+ ndp->ni_makeentry = 1;
+ if (*cp == '\0' && docache == 0)
+ ndp->ni_makeentry = 0;
+ ndp->ni_isdotdot = (ndp->ni_namelen == 2 &&
+ ndp->ni_dent.d_name[1] == '.' && ndp->ni_dent.d_name[0] == '.');
/*
* Check for degenerate name (e.g. / or "")
* which is a way of talking about a directory,
* e.g. like "/." or ".".
*/
- if (u.u_dent.d_name[0] == 0) {
- if (flag != LOOKUP || lockparent) {
- u.u_error = EISDIR;
+ if (ndp->ni_ptr[0] == '\0') {
+ if (flag != LOOKUP || wantparent) {
+ error = EISDIR;
goto bad;
}
- brelse(nbp);
- return (dp);
+ free(ndp->ni_pnbuf, M_NAMEI);
+ if (!(ndp->ni_nameiop & LOCKLEAF))
+ VOP_UNLOCK(dp);
+ ndp->ni_vp = dp;
+ return (0);
}
/*
- * We now have a segment name to search for, and a directory to search.
- *
- * Before tediously performing a linear scan of the directory,
- * check the name cache to see if the directory/name pair
- * we are looking for is known already. We don't do this
- * if the segment name is long, simply so the cache can avoid
- * holding long names (which would either waste space, or
- * add greatly to the complexity).
+ * Handle "..": two special cases.
+ * 1. If at root directory (e.g. after chroot)
+ * then ignore it so can't get out.
+ * 2. If this vnode is the root of a mounted
+ * file system, then replace it with the
+ * vnode which was mounted on so we take the
+ * .. in the other file system.
*/
- if (u.u_dent.d_namlen > NCHNAMLEN) {
- nchstats.ncs_long++;
- docache = 0;
- } else {
- nhp = &nchash[NHASH(hash, dp->i_number, dp->i_dev)];
- for (ncp = nhp->nch_forw; ncp != (struct nch *)nhp;
- ncp = ncp->nc_forw) {
- if (ncp->nc_ino == dp->i_number &&
- ncp->nc_dev == dp->i_dev &&
- ncp->nc_nlen == u.u_dent.d_namlen &&
- !bcmp(ncp->nc_name, u.u_dent.d_name, ncp->nc_nlen))
- break;
- }
-
- if (ncp == (struct nch *)nhp) {
- nchstats.ncs_miss++;
- ncp = NULL;
- } else {
- if (*cp == '/' || docache) {
-
- nchstats.ncs_goodhits++;
-
- /*
- * move this slot to end of LRU
- * chain, if not already there
- */
- if (ncp->nc_nxt) {
- /* remove from LRU chain */
- *ncp->nc_prev = ncp->nc_nxt;
- ncp->nc_nxt->nc_prev = ncp->nc_prev;
-
- /* and replace at end of it */
- ncp->nc_nxt = NULL;
- ncp->nc_prev = nchtail;
- *nchtail = ncp;
- nchtail = &ncp->nc_nxt;
- }
-
- pdp = dp;
- dp = ncp->nc_ip;
- if (dp == NULL)
- panic("nami: null cache ino");
- if (pdp != dp) {
- ilock(dp);
- dp->i_count++;
- iunlock(pdp);
- } else
- dp->i_count++;
-
- u.u_dent.d_ino = dp->i_number;
- /* u_dent.d_reclen is garbage ... */
-
- goto haveino;
+ if (ndp->ni_isdotdot) {
+ for (;;) {
+ if (dp == ndp->ni_rdir || dp == rootdir) {
+ ndp->ni_dvp = dp;
+ dp->v_count++;
+ goto nextname;
}
-
- /*
- * last segment and we are renaming or deleting
- * or otherwise don't want cache entry to exist
- */
-
- nchstats.ncs_badhits++;
-
- /* remove from LRU chain */
- *ncp->nc_prev = ncp->nc_nxt;
- if (ncp->nc_nxt)
- ncp->nc_nxt->nc_prev = ncp->nc_prev;
- else
- nchtail = ncp->nc_prev;
-
- /* remove from hash chain */
- remque(ncp);
-
- /* release ref on the inode */
- irele(ncp->nc_ip);
- ncp->nc_ip = NULL;
-
- /* insert at head of LRU list (first to grab) */
- ncp->nc_nxt = nchhead;
- ncp->nc_prev = &nchhead;
- nchhead->nc_prev = &ncp->nc_nxt;
- nchhead = ncp;
-
- /* and make a dummy hash chain */
- ncp->nc_forw = ncp;
- ncp->nc_back = ncp;
-
- ncp = NULL;
- }
- }
-
- /*
- * Suppress search for slots unless creating
- * file and at end of pathname, in which case
- * we watch for a place to put the new file in
- * case it doesn't already exist.
- */
- slotstatus = FOUND;
- if (flag == CREATE && *cp == 0) {
- slotstatus = NONE;
- slotfreespace = 0;
- slotneeded = DIRSIZ(&u.u_dent);
- }
- /*
- * If this is the same directory that this process
- * previously searched, pick up where we last left off.
- * We cache only lookups as these are the most common
- * and have the greatest payoff. Caching CREATE has little
- * benefit as it usually must search the entire directory
- * to determine that the entry does not exist. Caching the
- * location of the last DELETE has not reduced profiling time
- * and hence has been removed in the interest of simplicity.
- */
- if (flag != LOOKUP || dp->i_number != u.u_ncache.nc_inumber ||
- dp->i_dev != u.u_ncache.nc_dev) {
- u.u_offset = 0;
- numdirpasses = 1;
- } else {
- if ((dp->i_flag & ICHG) || dp->i_ctime >= u.u_ncache.nc_time) {
- u.u_ncache.nc_prevoffset &= ~(DIRBLKSIZ - 1);
- u.u_ncache.nc_time = time.tv_sec;
- }
- u.u_offset = u.u_ncache.nc_prevoffset;
- entryoffsetinblock = blkoff(fs, u.u_offset);
- if (entryoffsetinblock != 0) {
- bp = blkatoff(dp, u.u_offset, (char **)0);
- if (bp == 0)
- goto bad;
- }
- numdirpasses = 2;
- nchstats.ncs_2passes++;
- }
- endsearch = roundup(dp->i_size, DIRBLKSIZ);
-
-searchloop:
- while (u.u_offset < endsearch) {
- /*
- * If offset is on a block boundary,
- * read the next directory block.
- * Release previous if it exists.
- */
- if (blkoff(fs, u.u_offset) == 0) {
- if (bp != NULL)
- brelse(bp);
- bp = blkatoff(dp, u.u_offset, (char **)0);
- if (bp == 0)
- goto bad;
- entryoffsetinblock = 0;
- }
-
- /*
- * If still looking for a slot, and at a DIRBLKSIZE
- * boundary, have to start looking for free space
- * again.
- */
- if (slotstatus == NONE &&
- (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) {
- slotoffset = -1;
- slotfreespace = 0;
- }
-
- /*
- * Get pointer to next entry, and do consistency checking:
- * record length must be multiple of 4
- * record length must not be zero
- * entry must fit in rest of this DIRBLKSIZ block
- * record must be large enough to contain name
- * When dirchk is set we also check:
- * name is not longer than MAXNAMLEN
- * name must be as long as advertised, and null terminated
- * Checking last two conditions is done only when dirchk is
- * set, to save time.
- */
- ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock);
- i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
- if ((ep->d_reclen & 0x3) || ep->d_reclen == 0 ||
- ep->d_reclen > i || DIRSIZ(ep) > ep->d_reclen ||
- dirchk && (ep->d_namlen > MAXNAMLEN || dirbadname(ep))) {
- dirbad(dp, "mangled entry");
- u.u_offset += i;
- entryoffsetinblock += i;
- continue;
- }
-
- /*
- * If an appropriate sized slot has not yet been found,
- * check to see if one is available. Also accumulate space
- * in the current block so that we can determine if
- * compaction is viable.
- */
- if (slotstatus != FOUND) {
- int size = ep->d_reclen;
-
- if (ep->d_ino != 0)
- size -= DIRSIZ(ep);
- if (size > 0) {
- if (size >= slotneeded) {
- slotstatus = FOUND;
- slotoffset = u.u_offset;
- slotsize = ep->d_reclen;
- } else if (slotstatus == NONE) {
- slotfreespace += size;
- if (slotoffset == -1)
- slotoffset = u.u_offset;
- if (slotfreespace >= slotneeded) {
- slotstatus = COMPACT;
- slotsize =
- u.u_offset+ep->d_reclen -
- slotoffset;
- }
- }
- }
- }
-
- /*
- * Check for a name match.
- */
- if (ep->d_ino) {
- if (ep->d_namlen == u.u_dent.d_namlen &&
- !bcmp(u.u_dent.d_name, ep->d_name, ep->d_namlen))
- goto found;
- }
- prevoff = u.u_offset;
- u.u_offset += ep->d_reclen;
- entryoffsetinblock += ep->d_reclen;
- }
-/* notfound: */
- /*
- * If we started in the middle of the directory and failed
- * to find our target, we must check the beginning as well.
- */
- if (numdirpasses == 2) {
- numdirpasses--;
- u.u_offset = 0;
- endsearch = u.u_ncache.nc_prevoffset;
- goto searchloop;
- }
- /*
- * If creating, and at end of pathname and current
- * directory has not been removed, then can consider
- * allowing file to be created.
- */
- if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) {
- /*
- * Access for write is interpreted as allowing
- * creation of files in the directory.
- */
- if (access(dp, IWRITE))
- goto bad;
- /*
- * Return an indication of where the new directory
- * entry should be put. If we didn't find a slot,
- * then set u.u_count to 0 indicating that the
- * new slot belongs at the end of the directory.
- * If we found a slot, then the new entry can be
- * put in the range [u.u_offset..u.u_offset+u.u_count)
- */
- if (slotstatus == NONE) {
- u.u_offset = roundup(dp->i_size, DIRBLKSIZ);
- u.u_count = 0;
- } else {
- u.u_offset = slotoffset;
- u.u_count = slotsize;
+ if ((dp->v_flag & VROOT) == 0)
+ break;
+ tdp = dp;
+ dp = dp->v_mount->m_vnodecovered;
+ vput(tdp);
+ VOP_LOCK(dp);
+ dp->v_count++;
}
- dp->i_flag |= IUPD|ICHG;
- if (bp)
- brelse(bp);
- brelse(nbp);
- /*
- * We return with the directory locked, so that
- * the parameters we set up above will still be
- * valid if we actually decide to do a direnter().
- * We return NULL to indicate that the entry doesn't
- * currently exist, leaving a pointer to the (locked)
- * directory inode in u.u_pdir.
- */
- u.u_pdir = dp;
- return (NULL);
- }
- u.u_error = ENOENT;
- goto bad;
-found:
- if (numdirpasses == 2)
- nchstats.ncs_pass2++;
- /*
- * Check that directory length properly reflects presence
- * of this entry.
- */
- if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) {
- dirbad(dp, "i_size too small");
- dp->i_size = entryoffsetinblock + DIRSIZ(ep);
- dp->i_flag |= IUPD|ICHG;
}
/*
- * Found component in pathname.
- * If the final component of path name, save information
- * in the cache as to where the entry was found.
- */
- if (*cp == '\0' && flag == LOOKUP) {
- u.u_ncache.nc_prevoffset = u.u_offset;
- u.u_ncache.nc_inumber = dp->i_number;
- u.u_ncache.nc_dev = dp->i_dev;
- u.u_ncache.nc_time = time.tv_sec;
- }
- /*
- * Save directory entry in u.u_dent,
- * and release directory buffer.
- */
- bcopy((caddr_t)ep, (caddr_t)&u.u_dent, (u_int)DIRSIZ(ep));
- brelse(bp);
- bp = NULL;
-
- /*
- * If deleting, and at end of pathname, return
- * parameters which can be used to remove file.
- * If the lockparent flag isn't set, we return only
- * the directory (in u.u_pdir), otherwise we go
- * on and lock the inode, being careful with ".".
+ * We now have a segment name to search for, and a directory to search.
*/
- if (flag == DELETE && *cp == 0) {
+ if (error = VOP_LOOKUP(dp, ndp)) {
+ if (ndp->ni_vp != NULL)
+ panic("leaf should be empty");
+#ifdef NAMEI_DIAGNOSTIC
+ printf("not found\n");
+#endif
/*
- * Write access to directory required to delete files.
+ * If creating and at end of pathname, then can consider
+ * allowing file to be created.
*/
- if (access(dp, IWRITE))
+ if (ndp->ni_dvp->v_mount->m_flag & M_RDONLY)
+ error = EROFS;
+ if (flag == LOOKUP || flag == DELETE ||
+ error != ENOENT || *cp != 0)
goto bad;
- u.u_pdir = dp; /* for dirremove() */
/*
- * Return pointer to current entry in u.u_offset,
- * and distance past previous entry (if there
- * is a previous entry in this block) in u.u_count.
- * Save directory inode pointer in u.u_pdir for dirremove().
+ * We return with ni_vp NULL to indicate that the entry
+ * doesn't currently exist, leaving a pointer to the
+ * (possibly locked) directory inode in ndp->ni_dvp.
*/
- if ((u.u_offset&(DIRBLKSIZ-1)) == 0)
- u.u_count = 0;
- else
- u.u_count = u.u_offset - prevoff;
- if (lockparent) {
- if (dp->i_number == u.u_dent.d_ino)
- dp->i_count++;
- else {
- dp = iget(dp->i_dev, fs, u.u_dent.d_ino);
- if (dp == NULL) {
- iput(u.u_pdir);
- goto bad;
- }
- /*
- * If directory is setuid, then user must own
- * the directory, or the file in it, else he
- * may not delete it (unless he's root). This
- * implements append-only directories.
- */
- if ((u.u_pdir->i_mode & ISUID) &&
- u.u_uid != 0 &&
- u.u_uid != u.u_pdir->i_uid &&
- dp->i_uid != u.u_uid) {
- iput(u.u_pdir);
- u.u_error = EPERM;
- goto bad;
- }
- }
- }
- brelse(nbp);
- return (dp);
- }
-
- /*
- * Special handling for ".." allowing chdir out of mounted
- * file system: indirect .. in root inode to reevaluate
- * in directory file system was mounted on.
- */
- isdotdot = 0;
- if (bcmp(u.u_dent.d_name, "..", 3) == 0) {
- isdotdot++;
- if (dp == u.u_rdir)
- u.u_dent.d_ino = dp->i_number;
- else if (u.u_dent.d_ino == ROOTINO &&
- dp->i_number == ROOTINO) {
- for (i = 1; i < NMOUNT; i++)
- if (mount[i].m_bufp != NULL &&
- mount[i].m_dev == dp->i_dev) {
- iput(dp);
- dp = mount[i].m_inodp;
- ilock(dp);
- dp->i_count++;
- fs = dp->i_fs;
- cp -= 2; /* back over .. */
- goto dirloop2;
- }
- }
+ FREE(ndp->ni_pnbuf, M_NAMEI);
+ return (0); /* should this be ENOENT? */
}
+#ifdef NAMEI_DIAGNOSTIC
+ printf("found\n");
+#endif
/*
- * If rewriting (rename), return the inode and the
- * information required to rewrite the present directory
- * Must get inode of directory entry to verify it's a
- * regular file, or empty directory.
+ * Check for symbolic link
*/
- if ((flag == CREATE && lockparent) && *cp == 0) {
- if (access(dp, IWRITE))
- goto bad;
- u.u_pdir = dp; /* for dirrewrite() */
- /*
- * Careful about locking second inode.
- * This can only occur if the target is ".".
- */
- if (dp->i_number == u.u_dent.d_ino) {
- u.u_error = EISDIR; /* XXX */
- goto bad;
- }
- dp = iget(dp->i_dev, fs, u.u_dent.d_ino);
- if (dp == NULL) {
- iput(u.u_pdir);
- goto bad;
+ dp = ndp->ni_vp;
+ if ((dp->v_type == VLNK) &&
+ ((ndp->ni_nameiop & FOLLOW) || *ndp->ni_next == '/')) {
+ struct iovec aiov;
+ struct uio auio;
+ int linklen;
+
+ if (++ndp->ni_loopcnt > MAXSYMLINKS) {
+ error = ELOOP;
+ goto bad2;
}
- brelse(nbp);
- return (dp);
- }
-
- /*
- * Check for symbolic link, which may require us to massage the
- * name before we continue translation. We do not `iput' the
- * directory because we may need it again if the symbolic link
- * is relative to the current directory. Instead we save it
- * unlocked as "pdp". We must get the target inode before unlocking
- * the directory to insure that the inode will not be removed
- * before we get it. We prevent deadlock by always fetching
- * inodes from the root, moving down the directory tree. Thus
- * when following backward pointers ".." we must unlock the
- * parent directory before getting the requested directory.
- * There is a potential race condition here if both the current
- * and parent directories are removed before the `iget' for the
- * inode associated with ".." returns. We hope that this occurs
- * infrequently since we cannot avoid this race condition without
- * implementing a sophisticated deadlock detection algorithm.
- * Note also that this simple deadlock detection scheme will not
- * work if the file system has any hard links other than ".."
- * that point backwards in the directory structure.
- */
- pdp = dp;
- if (isdotdot) {
- iunlock(pdp); /* race to get the inode */
- dp = iget(dp->i_dev, fs, u.u_dent.d_ino);
- if (dp == NULL)
+ if (ndp->ni_pathlen == 1)
+ MALLOC(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
+ else
+ cp = ndp->ni_pnbuf;
+ aiov.iov_base = cp;
+ aiov.iov_len = MAXPATHLEN;
+ auio.uio_iov = &aiov;
+ auio.uio_iovcnt = 1;
+ auio.uio_offset = 0;
+ auio.uio_rw = UIO_READ;
+ auio.uio_segflg = UIO_SYSSPACE;
+ auio.uio_resid = MAXPATHLEN;
+ if (error = VOP_READLINK(dp, &auio, ndp->ni_cred)) {
+ if (ndp->ni_pathlen == 1)
+ free(cp, M_NAMEI);
goto bad2;
- } else if (dp->i_number == u.u_dent.d_ino) {
- dp->i_count++; /* we want ourself, ie "." */
- } else {
- dp = iget(dp->i_dev, fs, u.u_dent.d_ino);
- iunlock(pdp);
- if (dp == NULL)
+ }
+ linklen = MAXPATHLEN - auio.uio_resid;
+ if (linklen + ndp->ni_pathlen >= MAXPATHLEN) {
+ if (ndp->ni_pathlen == 1)
+ free(cp, M_NAMEI);
+ error = ENAMETOOLONG;
goto bad2;
- }
-
- /*
- * insert name into cache (if we want it, and it isn't "." or "..")
- *
- * all other cases where making a cache entry would be wrong
- * have already departed from the code sequence somewhere above.
- */
- if (bcmp(u.u_dent.d_name, ".", 2) != 0 && !isdotdot && docache) {
- if (ncp != NULL)
- panic("nami: duplicating cache");
-
- /*
- * free the cache slot at head of lru chain
- */
- if (ncp = nchhead) {
- /* remove from lru chain */
- *ncp->nc_prev = ncp->nc_nxt;
- if (ncp->nc_nxt)
- ncp->nc_nxt->nc_prev = ncp->nc_prev;
- else
- nchtail = ncp->nc_prev;
-
- /* remove from old hash chain */
- remque(ncp);
-
- /* drop hold on inode (if we had one) */
- if (ncp->nc_ip)
- irele(ncp->nc_ip);
-
- /* grab the inode we just found */
- ncp->nc_ip = dp;
- dp->i_count++;
-
- /* fill in cache info */
- ncp->nc_ino = pdp->i_number; /* parents inum */
- ncp->nc_dev = pdp->i_dev; /* & device */
- ncp->nc_idev = dp->i_dev; /* our device */
- ncp->nc_nlen = u.u_dent.d_namlen;
- bcopy(u.u_dent.d_name, ncp->nc_name, ncp->nc_nlen);
-
- /* link at end of lru chain */
- ncp->nc_nxt = NULL;
- ncp->nc_prev = nchtail;
- *nchtail = ncp;
- nchtail = &ncp->nc_nxt;
-
- /* and insert on hash chain */
- insque(ncp, nhp);
}
+ if (ndp->ni_pathlen == 1) {
+ FREE(ndp->ni_pnbuf, M_NAMEI);
+ ndp->ni_pnbuf = cp;
+ ndp->ni_pnbuf[linklen] = '\0';
+ } else
+ bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
+ ndp->ni_ptr = cp;
+ ndp->ni_pathlen += linklen;
+ vput(dp);
+ dp = ndp->ni_dvp;
+ if (lockparent && *ndp->ni_next == '\0')
+ VOP_UNLOCK(dp);
+ goto start;
}
-haveino:
- fs = dp->i_fs;
-
/*
- * Check for symbolic link
+ * Check to see if the vnode has been mounted on;
+ * if so find the root of the mounted file system.
*/
- if ((dp->i_mode & IFMT) == IFLNK && (follow || *cp == '/')) {
- u_int pathlen = strlen(cp) + 1;
-
- if (dp->i_size + pathlen >= MAXPATHLEN - 1 ||
- ++nlink > MAXSYMLINKS) {
- u.u_error = ELOOP;
- goto bad2;
+mntloop:
+ while (dp->v_type == VDIR && (mp = dp->v_mountedhere)) {
+ while(mp->m_flag & M_MLOCK) {
+ mp->m_flag |= M_MWAIT;
+ sleep((caddr_t)mp, PVFS);
+ goto mntloop;
}
- ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen);
- u.u_error =
- rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size,
- 0, 1, (int *)0);
- if (u.u_error)
+ error = VFS_ROOT(dp->v_mountedhere, &tdp);
+ if (error)
goto bad2;
- cp = nbp->b_un.b_addr;
- iput(dp);
- if (*cp == '/') {
- irele(pdp);
- while (*cp == '/')
- cp++;
- if ((dp = u.u_rdir) == NULL)
- dp = rootdir;
- ilock(dp);
- dp->i_count++;
- } else {
- dp = pdp;
- ilock(dp);
- }
- fs = dp->i_fs;
- goto dirloop;
+ vput(dp);
+ ndp->ni_vp = dp = tdp;
}
+nextname:
/*
* Not a symbolic link. If more pathname,
* continue at next component, else return.
*/
- if (*cp == '/') {
- while (*cp == '/')
- cp++;
- irele(pdp);
- goto dirloop;
- }
- brelse(nbp);
- if (lockparent)
- u.u_pdir = pdp;
- else
- irele(pdp);
- return (dp);
-bad2:
- irele(pdp);
-bad:
- if (bp)
- brelse(bp);
- if (dp)
- iput(dp);
- brelse(nbp);
- return (NULL);
-}
-
-
-dirbad(ip, how)
- struct inode *ip;
- char *how;
-{
-
- printf("%s: bad dir ino %d at offset %d: %s\n",
- ip->i_fs->fs_fsmnt, ip->i_number, u.u_offset, how);
-}
-
-dirbadname(ep)
- register struct direct *ep;
-{
- register int i;
-
- for (i = 0; i < ep->d_namlen; i++)
- if (ep->d_name[i] == 0)
- return (1);
- return (ep->d_name[i]);
-}
-
-/*
- * Write a directory entry after a call to namei, using the parameters
- * which it left in the u. area. The argument ip is the inode which
- * the new directory entry will refer to. The u. area field u.u_pdir is
- * a pointer to the directory to be written, which was left locked by
- * namei. Remaining parameters (u.u_offset, u.u_count) indicate
- * how the space for the new entry is to be gotten.
- */
-direnter(ip)
- struct inode *ip;
-{
- register struct direct *ep, *nep;
- struct buf *bp;
- int loc, spacefree, error = 0;
- u_int dsize;
- int newentrysize;
- char *dirbuf;
-
- u.u_dent.d_ino = ip->i_number;
- u.u_segflg = 1;
- newentrysize = DIRSIZ(&u.u_dent);
- if (u.u_count == 0) {
- /*
- * If u.u_count is 0, then namei could find no space in the
- * directory. In this case u.u_offset will be on a directory
- * block boundary and we will write the new entry into a fresh
- * block.
- */
- if (u.u_offset&(DIRBLKSIZ-1))
- panic("wdir: newblk");
- u.u_dent.d_reclen = DIRBLKSIZ;
- error = rdwri(UIO_WRITE, u.u_pdir, (caddr_t)&u.u_dent,
- newentrysize, u.u_offset, 1, (int *)0);
- iput(u.u_pdir);
- return (error);
- }
-
- /*
- * If u.u_count is non-zero, then namei found space for the
- * new entry in the range u.u_offset to u.u_offset+u.u_count.
- * in the directory. To use this space, we may have to compact
- * the entries located there, by copying them together towards
- * the beginning of the block, leaving the free space in
- * one usable chunk at the end.
- */
-
- /*
- * Increase size of directory if entry eats into new space.
- * This should never push the size past a new multiple of
- * DIRBLKSIZE.
- */
- if (u.u_offset + u.u_count > u.u_pdir->i_size)
- u.u_pdir->i_size = u.u_offset + u.u_count;
-
- /*
- * Get the block containing the space for the new directory
- * entry. Should return error by result instead of u.u_error.
- */
- bp = blkatoff(u.u_pdir, u.u_offset, (char **)&dirbuf);
- if (bp == 0) {
- iput(u.u_pdir);
- return (u.u_error);
- }
-
- /*
- * Find space for the new entry. In the simple case, the
- * entry at offset base will have the space. If it does
- * not, then namei arranged that compacting the region
- * u.u_offset to u.u_offset+u.u_count would yield the space.
- */
- ep = (struct direct *)dirbuf;
- dsize = DIRSIZ(ep);
- spacefree = ep->d_reclen - dsize;
- for (loc = ep->d_reclen; loc < u.u_count; ) {
- nep = (struct direct *)(dirbuf + loc);
- if (ep->d_ino) {
- /* trim the existing slot */
- ep->d_reclen = dsize;
- ep = (struct direct *)((char *)ep + dsize);
- } else {
- /* overwrite; nothing there; header is ours */
- spacefree += dsize;
+ ndp->ni_ptr = ndp->ni_next;
+ if (*ndp->ni_ptr == '/') {
+ while (*ndp->ni_ptr == '/') {
+ ndp->ni_ptr++;
+ ndp->ni_pathlen--;
}
- dsize = DIRSIZ(nep);
- spacefree += nep->d_reclen - dsize;
- loc += nep->d_reclen;
- bcopy((caddr_t)nep, (caddr_t)ep, dsize);
+ vrele(ndp->ni_dvp);
+ goto dirloop;
}
/*
- * Update the pointer fields in the previous entry (if any),
- * copy in the new entry, and write out the block.
+ * Check for read-only file systems and executing texts
*/
- if (ep->d_ino == 0) {
- if (spacefree + dsize < newentrysize)
- panic("wdir: compact1");
- u.u_dent.d_reclen = spacefree + dsize;
- } else {
- if (spacefree < newentrysize)
- panic("wdir: compact2");
- u.u_dent.d_reclen = spacefree;
- ep->d_reclen = dsize;
- ep = (struct direct *)((char *)ep + dsize);
- }
- bcopy((caddr_t)&u.u_dent, (caddr_t)ep, (u_int)newentrysize);
- bwrite(bp);
- u.u_pdir->i_flag |= IUPD|ICHG;
- iput(u.u_pdir);
- return (error);
-}
-
-/*
- * Remove a directory entry after a call to namei, using the
- * parameters which it left in the u. area. The u. entry
- * u_offset contains the offset into the directory of the
- * entry to be eliminated. The u_count field contains the
- * size of the previous record in the directory. If this
- * is 0, the first entry is being deleted, so we need only
- * zero the inode number to mark the entry as free. If the
- * entry isn't the first in the directory, we must reclaim
- * the space of the now empty record by adding the record size
- * to the size of the previous entry.
- */
-dirremove()
-{
- register struct inode *dp = u.u_pdir;
- register struct buf *bp;
- struct direct *ep;
-
- if (u.u_count == 0) {
- /*
- * First entry in block: set d_ino to zero.
- */
- u.u_dent.d_ino = 0;
- (void) rdwri(UIO_WRITE, dp, (caddr_t)&u.u_dent,
- (int)DIRSIZ(&u.u_dent), u.u_offset, 1, (int *)0);
- } else {
- /*
- * Collapse new free space into previous entry.
- */
- bp = blkatoff(dp, (int)(u.u_offset - u.u_count), (char **)&ep);
- if (bp == 0)
- return (0);
- ep->d_reclen += u.u_dent.d_reclen;
- bwrite(bp);
- dp->i_flag |= IUPD|ICHG;
- }
- return (1);
-}
-
-/*
- * Rewrite an existing directory entry to point at the inode
- * supplied. The parameters describing the directory entry are
- * set up by a call to namei.
- */
-dirrewrite(dp, ip)
- struct inode *dp, *ip;
-{
+ if (flag != LOOKUP && (error = vn_access(dp, VWRITE, ndp->ni_cred)))
+ goto bad2;
+ if (!wantparent)
+ vrele(ndp->ni_dvp);
+ if ((ndp->ni_nameiop & LOCKLEAF) == 0)
+ VOP_UNLOCK(dp);
+ FREE(ndp->ni_pnbuf, M_NAMEI);
+ return (0);
- u.u_dent.d_ino = ip->i_number;
- u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&u.u_dent,
- (int)DIRSIZ(&u.u_dent), u.u_offset, 1, (int *)0);
- iput(dp);
-}
-
-/*
- * Return buffer with contents of block "offset"
- * from the beginning of directory "ip". If "res"
- * is non-zero, fill it in with a pointer to the
- * remaining space in the directory.
- */
-struct buf *
-blkatoff(ip, offset, res)
- struct inode *ip;
- off_t offset;
- char **res;
-{
- register struct fs *fs = ip->i_fs;
- daddr_t lbn = lblkno(fs, offset);
- int base = blkoff(fs, offset);
- int bsize = blksize(fs, ip, lbn);
- daddr_t bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, base, bsize));
- register struct buf *bp;
-
- if (u.u_error)
- return (0);
- bp = bread(ip->i_dev, bn, bsize);
- if (bp->b_flags & B_ERROR) {
- brelse(bp);
- return (0);
- }
- if (res)
- *res = bp->b_un.b_addr + base;
- return (bp);
-}
-
-/*
- * Check if a directory is empty or not.
- * Inode supplied must be locked.
- *
- * Using a struct dirtemplate here is not precisely
- * what we want, but better than using a struct direct.
- *
- * NB: does not handle corrupted directories.
- */
-dirempty(ip)
- register struct inode *ip;
-{
- register off_t off;
- struct dirtemplate dbuf;
- register struct direct *dp = (struct direct *)&dbuf;
- int error, count;
-#define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
-
- for (off = 0; off < ip->i_size; off += dp->d_reclen) {
- error = rdwri(UIO_READ, ip, (caddr_t)dp, MINDIRSIZ,
- off, 1, &count);
- /*
- * Since we read MINDIRSIZ, residual must
- * be 0 unless we're at end of file.
- */
- if (error || count != 0)
- return (0);
- /* skip empty entries */
- if (dp->d_ino == 0)
- continue;
- /* accept only "." and ".." */
- if (dp->d_namlen > 2)
- return (0);
- if (dp->d_name[0] != '.')
- return (0);
- /*
- * At this point d_namlen must be 1 or 2.
- * 1 implies ".", 2 implies ".." if second
- * char is also "."
- */
- if (dp->d_namlen == 1 || dp->d_name[1] == '.')
- continue;
- return (0);
- }
- return (1);
-}
-
-/*
- * Check if source directory is in the path of the target directory.
- * Target is supplied locked, source is unlocked.
- * The target is always iput() before returning.
- */
-checkpath(source, target)
- struct inode *source, *target;
-{
- struct dirtemplate dirbuf;
- register struct inode *ip;
- int error = 0;
-
- ip = target;
- if (ip->i_number == source->i_number) {
- error = EEXIST;
- goto out;
- }
- if (ip->i_number == ROOTINO)
- goto out;
-
- for (;;) {
- if ((ip->i_mode&IFMT) != IFDIR) {
- error = ENOTDIR;
- break;
- }
- error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf,
- sizeof (struct dirtemplate), (off_t)0, 1, (int *)0);
- if (error != 0)
- break;
- if (dirbuf.dotdot_namlen != 2 ||
- bcmp(dirbuf.dotdot_name, "..", 3) != 0) {
- error = ENOTDIR;
- break;
- }
- if (dirbuf.dotdot_ino == source->i_number) {
- error = EINVAL;
- break;
- }
- if (dirbuf.dotdot_ino == ROOTINO)
- break;
- iput(ip);
- ip = iget(ip->i_dev, ip->i_fs, dirbuf.dotdot_ino);
- if (ip == NULL) {
- error = u.u_error;
- break;
- }
- }
-
-out:
- if (error == ENOTDIR)
- printf("checkpath: .. not a directory\n");
- if (ip != NULL)
- iput(ip);
+bad2:
+ if (lockparent && *ndp->ni_next == '\0')
+ VOP_UNLOCK(ndp->ni_dvp);
+ vrele(ndp->ni_dvp);
+bad:
+ vput(dp);
+ ndp->ni_vp = NULL;
+ FREE(ndp->ni_pnbuf, M_NAMEI);
return (error);
}
-
-/*
- * Name cache initialization, from main() when we are booting
- */
-nchinit()
-{
- register union nchash *nchp;
- register struct nch *ncp;
-
- nchhead = 0;
- nchtail = &nchhead;
-
- for (ncp = nch; ncp < &nch[nchsize]; ncp++) {
- ncp->nc_forw = ncp; /* hash chain */
- ncp->nc_back = ncp;
-
- ncp->nc_nxt = NULL; /* lru chain */
- *nchtail = ncp;
- ncp->nc_prev = nchtail;
- nchtail = &ncp->nc_nxt;
-
- /* all else is zero already */
- }
-
- for (nchp = nchash; nchp < &nchash[NCHHASH]; nchp++) {
- nchp->nch_head[0] = nchp;
- nchp->nch_head[1] = nchp;
- }
-}
-
-/*
- * Cache flush, called when filesys is umounted to
- * remove entries that would now be invalid
- *
- * The line "nxtcp = nchhead" near the end is to avoid potential problems
- * if the cache lru chain is modified while we are dumping the
- * inode. This makes the algorithm O(n^2), but do you think I care?
- */
-nchinval(dev)
- register dev_t dev;
-{
- register struct nch *ncp, *nxtcp;
-
- for (ncp = nchhead; ncp; ncp = nxtcp) {
- nxtcp = ncp->nc_nxt;
-
- if (ncp->nc_ip == NULL ||
- (ncp->nc_idev != dev && ncp->nc_dev != dev))
- continue;
-
- ncp->nc_idev = NODEV;
- ncp->nc_dev = NODEV;
- ncp->nc_ino = 0;
-
- /* remove the entry from its hash chain */
- remque(ncp);
- /* and make a dummy one */
- ncp->nc_forw = ncp;
- ncp->nc_back = ncp;
-
- /* delete this entry from LRU chain */
- *ncp->nc_prev = nxtcp;
- if (nxtcp)
- nxtcp->nc_prev = ncp->nc_prev;
- else
- nchtail = ncp->nc_prev;
-
- /* free the inode we had */
- irele(ncp->nc_ip);
- ncp->nc_ip = NULL;
-
- /* cause rescan of list, it may have altered */
- nxtcp = nchhead;
- /* put the now-free entry at head of LRU */
- ncp->nc_nxt = nxtcp;
- ncp->nc_prev = &nchhead;
- nxtcp->nc_prev = &ncp->nc_nxt;
- nchhead = ncp;
- }
-}