-/* ufs_lookup.c 4.20 82/07/30 */
-
-#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"
-
-#ifdef EFS
-extern int efs_major;
-#endif
+/*
+ * Copyright (c) 1989 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ *
+ * @(#)ufs_lookup.c 7.36 (Berkeley) %G%
+ */
-struct buf *blkatoff();
+#include <sys/param.h>
+#include <sys/namei.h>
+#include <sys/buf.h>
+#include <sys/file.h>
+#include <sys/mount.h>
+#include <sys/vnode.h>
+
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/inode.h>
+#include <ufs/ufs/dir.h>
+#include <ufs/ufs/ufsmount.h>
+#include <ufs/ufs/ufs_extern.h>
+
+struct nchstats nchstats;
+#ifdef DIAGNOSTIC
int dirchk = 1;
+#else
+int dirchk = 0;
+#endif
+
/*
- * Convert a pathname into a pointer to a locked inode,
- * with side effects usable in creating and removing files.
+ * Convert a component of a pathname into a pointer to a locked inode.
* This is a very central and rather complicated routine.
+ * If the file system is not maintained in a strict tree hierarchy,
+ * this can result in a deadlock situation (see comments in code below).
*
- * The func argument gives the routine which returns successive
- * characters of the name to be translated. The flag
- * argument is (0, 1, 2) depending on whether the name is to be
- * (looked up, created, deleted). The follow argument is 1 when
- * symbolic links are to be followed when they occur at the end of
- * the name translation process.
+ * 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, lookup 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 "."., but the caller must check to ensure it does an vrele and iput
+ * instead of two iputs.
*
- * Overall outline:
+ * Overall outline of ufs_lookup:
*
- * copy in name
- * get starting directory
- * dirloop:
* check accessibility of directory
- * dirloop2:
- * copy next component of name to u.u_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 return name
* search for name in directory, to found or notfound
* notfound:
- * if creating, return locked inode, leaving information on avail. slots
+ * if creating, return locked directory, leaving info on available slots
* else return error
* found:
* if at end of path and deleting, return information to allow delete
- * if .. and on mounted filesys, look in mount table for parent
- * if symbolic link, massage name in buffer and continue at dirloop
- * if more components of name, do next level at dirloop
- * return the answer as locked inode
+ * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
+ * inode and return info to allow rewrite
+ * if not at end, add name to cache; if at end and neither creating
+ * nor deleting, add name to cache
+ *
+ * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode unlocked.
*/
-struct inode *
-namei(func, flag, follow)
- int (*func)(), flag, follow;
+int
+ufs_lookup(vdp, ndp, p)
+ register struct vnode *vdp;
+ register struct nameidata *ndp;
+ struct proc *p;
{
- 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 fs *fs; /* file system that directory is in */
- register struct buf *bp = 0; /* a buffer of directory entries */
+ register struct inode *dp; /* the directory we are searching */
+ struct buf *bp; /* 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 slotoffset; /* 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 dirsize;
- int prevoff; /* u.u_offset of previous entry */
- int nlink = 0; /* number of symbolic links taken */
+ int numdirpasses; /* strategy for directory search */
+ int endsearch; /* offset to end directory search */
+ int prevoff; /* prev entry ndp->ni_ufs.ufs_offset */
struct inode *pdp; /* saved dp during symlink work */
- int i;
-
- /*
- * 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 != 2) {
- u.u_error = EPERM;
- goto bad;
- }
- cp++;
- if (cp >= nbp->b_un.b_addr + MAXPATHLEN) {
- u.u_error = ENOENT;
- goto bad;
- }
- }
- if (u.u_error)
- goto bad;
+ struct vnode *tdp; /* returned by VOP_VGET */
+ off_t enduseful; /* pointer past last used dir slot */
+ u_long bmask; /* block offset mask */
+ int flag; /* LOOKUP, CREATE, RENAME, or DELETE */
+ int lockparent; /* 1 => lockparent flag is set */
+ int wantparent; /* 1 => wantparent or lockparent flag */
+ int error;
- /*
- * Get starting directory.
- */
- cp = nbp->b_un.b_addr;
- if (*cp == '/') {
- while (*cp == '/')
- cp++;
- if ((dp = u.u_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 */
+ bp = NULL;
+ slotoffset = -1;
+ ndp->ni_dvp = vdp;
+ ndp->ni_vp = NULL;
+ dp = VTOI(vdp);
+ lockparent = ndp->ni_nameiop & LOCKPARENT;
+ flag = ndp->ni_nameiop & OPMASK;
+ wantparent = ndp->ni_nameiop & (LOCKPARENT|WANTPARENT);
- /*
- * 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.
*/
-#ifdef EFS
- if ((dp->i_mode & IFMT) == IFCHR && major(dp->i_rdev) == efs_major) {
- brelse(nbp);
- return(dp);
- }
-#endif
- if ((dp->i_mode&IFMT) != IFDIR) {
- u.u_error = ENOTDIR;
- goto bad;
- }
- if (access(dp, IEXEC))
- goto bad;
+ if ((dp->i_mode&IFMT) != IFDIR)
+ return (ENOTDIR);
+ if (error = ufs_access(vdp, VEXEC, ndp->ni_cred, p))
+ return (error);
-dirloop2:
/*
- * Copy next component of name to u.u_dent.
+ * 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.
*/
- for (i = 0; *cp != 0 && *cp != '/'; cp++) {
- if (i >= MAXNAMLEN) {
- u.u_error = ENOENT;
- goto bad;
+ if (error = cache_lookup(ndp)) {
+ int vpid; /* capability number of vnode */
+
+ if (error == ENOENT)
+ return (error);
+#ifdef PARANOID
+ if (vdp == ndp->ni_rdir && ndp->ni_isdotdot)
+ panic("ufs_lookup: .. through root");
+#endif
+ /*
+ * Get the next vnode in the path.
+ * See comment below starting `Step through' for
+ * an explaination of the locking protocol.
+ */
+ pdp = dp;
+ dp = VTOI(ndp->ni_vp);
+ vdp = ndp->ni_vp;
+ vpid = vdp->v_id;
+ if (pdp == dp) {
+ VREF(vdp);
+ error = 0;
+ } else if (ndp->ni_isdotdot) {
+ IUNLOCK(pdp);
+ error = vget(vdp);
+ if (!error && lockparent && *ndp->ni_next == '\0')
+ ILOCK(pdp);
+ } else {
+ error = vget(vdp);
+ if (!lockparent || error || *ndp->ni_next != '\0')
+ IUNLOCK(pdp);
}
- u.u_dent.d_name[i++] = *cp;
- }
- u.u_dent.d_namlen = i;
- u.u_dent.d_name[i] = 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) {
- u.u_error = ENOENT;
- goto bad;
+ /*
+ * Check that the capability number did not change
+ * while we were waiting for the lock.
+ */
+ if (!error) {
+ if (vpid == vdp->v_id)
+ return (0);
+ ufs_iput(dp);
+ if (lockparent && pdp != dp && *ndp->ni_next == '\0')
+ IUNLOCK(pdp);
}
- brelse(nbp);
- return (dp);
+ ILOCK(pdp);
+ dp = pdp;
+ vdp = ITOV(dp);
+ ndp->ni_vp = NULL;
}
/*
* case it doesn't already exist.
*/
slotstatus = FOUND;
- if (flag == 1 && *cp == 0) {
+ if ((flag == CREATE || flag == RENAME) && *ndp->ni_next == 0) {
slotstatus = NONE;
slotfreespace = 0;
- slotneeded = DIRSIZ(&u.u_dent);
+ slotneeded = ((sizeof (struct direct) - (MAXNAMLEN + 1)) +
+ ((ndp->ni_namelen + 1 + 3) &~ 3));
}
- dirsize = roundup(dp->i_size, DIRBLKSIZ);
- u.u_offset = 0;
- while (u.u_offset < dirsize) {
+ /*
+ * If there is cached information on a previous search of
+ * this directory, 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 or RENAME has not reduced
+ * profiling time and hence has been removed in the interest
+ * of simplicity.
+ */
+ bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
+ if (flag != LOOKUP || dp->i_diroff == 0 || dp->i_diroff > dp->i_size) {
+ ndp->ni_ufs.ufs_offset = 0;
+ numdirpasses = 1;
+ } else {
+ ndp->ni_ufs.ufs_offset = dp->i_diroff;
+ if ((entryoffsetinblock = ndp->ni_ufs.ufs_offset & bmask) &&
+ (error = VOP_BLKATOFF(vdp, ndp->ni_ufs.ufs_offset, NULL,
+ &bp)))
+ return (error);
+ numdirpasses = 2;
+ nchstats.ncs_2passes++;
+ }
+ endsearch = roundup(dp->i_size, DIRBLKSIZ);
+ enduseful = 0;
+
+searchloop:
+ while (ndp->ni_ufs.ufs_offset < endsearch) {
/*
- * If offset is on a block boundary,
- * read the next directory block.
- * Release previous if it exists.
+ * 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 ((ndp->ni_ufs.ufs_offset & bmask) == 0) {
if (bp != NULL)
brelse(bp);
- bp = blkatoff(dp, u.u_offset, (char **)0);
- if (bp == 0)
- goto bad;
+ if (error = VOP_BLKATOFF(vdp, ndp->ni_ufs.ufs_offset,
+ NULL, &bp))
+ return (error);
entryoffsetinblock = 0;
}
-
/*
* If still looking for a slot, and at a DIRBLKSIZE
- * boundary, have to start looking for free space
- * again.
+ * boundary, have to start looking for free space again.
*/
if (slotstatus == NONE &&
- (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) {
+ (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.
+ * Get pointer to next entry.
+ * Full validation checks are slow, so we only check
+ * enough to insure forward progress through the
+ * directory. Complete checks can be run by patching
+ * "dirchk" to be true.
*/
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;
+ if (ep->d_reclen == 0 ||
+ dirchk && ufs_dirbadentry(ep, entryoffsetinblock)) {
+ int i;
+
+ ufs_dirbad(dp, ndp->ni_ufs.ufs_offset, "mangled entry");
+ i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
+ ndp->ni_ufs.ufs_offset += i;
entryoffsetinblock += i;
continue;
}
if (size > 0) {
if (size >= slotneeded) {
slotstatus = FOUND;
- slotoffset = u.u_offset;
+ slotoffset = ndp->ni_ufs.ufs_offset;
slotsize = ep->d_reclen;
} else if (slotstatus == NONE) {
slotfreespace += size;
if (slotoffset == -1)
- slotoffset = u.u_offset;
+ slotoffset =
+ ndp->ni_ufs.ufs_offset;
if (slotfreespace >= slotneeded) {
slotstatus = COMPACT;
slotsize =
- u.u_offset+ep->d_reclen -
- slotoffset;
+ ndp->ni_ufs.ufs_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))
+ if (ep->d_namlen == ndp->ni_namelen &&
+ !bcmp(ndp->ni_ptr, ep->d_name,
+ (unsigned)ep->d_namlen)) {
+ /*
+ * Save directory entry's inode number and
+ * reclen in ndp->ni_ufs area, and release
+ * directory buffer.
+ */
+ ndp->ni_ufs.ufs_ino = ep->d_ino;
+ ndp->ni_ufs.ufs_reclen = ep->d_reclen;
+ brelse(bp);
goto found;
+ }
}
- prevoff = u.u_offset;
- u.u_offset += ep->d_reclen;
+ prevoff = ndp->ni_ufs.ufs_offset;
+ ndp->ni_ufs.ufs_offset += ep->d_reclen;
entryoffsetinblock += ep->d_reclen;
+ if (ep->d_ino)
+ enduseful = ndp->ni_ufs.ufs_offset;
}
/* 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--;
+ ndp->ni_ufs.ufs_offset = 0;
+ endsearch = dp->i_diroff;
+ goto searchloop;
+ }
+ if (bp != NULL)
+ brelse(bp);
/*
* If creating, and at end of pathname and current
- * directory has not been removed, then can consider allowing
- * file to be created.
+ * directory has not been removed, then can consider
+ * allowing file to be created.
*/
- if (flag == 1 && *cp == 0 && dp->i_nlink != 0) {
+ if ((flag == CREATE || flag == RENAME) &&
+ *ndp->ni_next == 0 && dp->i_nlink != 0) {
/*
* Access for write is interpreted as allowing
* creation of files in the directory.
*/
- if (access(dp, IWRITE))
- goto bad;
+ if (error = ufs_access(vdp, VWRITE, ndp->ni_cred, p))
+ return (error);
/*
* 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)
+ * then set ndp->ni_ufs.ufs_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 from ndp->ni_ufs.ufs_offset
+ * to ndp->ni_ufs.ufs_offset + ndp->ni_ufs.ufs_count.
*/
- if (slotstatus == NONE)
- u.u_count = 0;
- else {
- u.u_offset = slotoffset;
- u.u_count = slotsize;
+ if (slotstatus == NONE) {
+ ndp->ni_ufs.ufs_offset = roundup(dp->i_size, DIRBLKSIZ);
+ ndp->ni_ufs.ufs_count = 0;
+ enduseful = ndp->ni_ufs.ufs_offset;
+ } else {
+ ndp->ni_ufs.ufs_offset = slotoffset;
+ ndp->ni_ufs.ufs_count = slotsize;
+ if (enduseful < slotoffset + slotsize)
+ enduseful = slotoffset + slotsize;
}
+ ndp->ni_ufs.ufs_endoff = roundup(enduseful, DIRBLKSIZ);
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.
+ * We return ni_vp == NULL to indicate that the entry
+ * does not currently exist; we leave a pointer to
+ * the (locked) directory inode in ndp->ni_dvp.
+ * The pathname buffer is saved so that the name
+ * can be obtained later.
+ *
+ * NB - if the directory is unlocked, then this
+ * information cannot be used.
*/
- u.u_pdir = dp;
- return (NULL);
+ ndp->ni_nameiop |= SAVENAME;
+ if (!lockparent)
+ IUNLOCK(dp);
}
- u.u_error = ENOENT;
- goto bad;
+ /*
+ * Insert name into cache (as non-existent) if appropriate.
+ */
+ if (ndp->ni_makeentry && flag != CREATE)
+ cache_enter(ndp);
+ return (ENOENT);
+
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");
+ ufs_dirbad(dp, ndp->ni_ufs.ufs_offset, "i_size too small");
dp->i_size = entryoffsetinblock + DIRSIZ(ep);
dp->i_flag |= IUPD|ICHG;
}
/*
- * Found component in pathname; save directory
- * entry in u.u_dent, and release directory buffer.
+ * Found component in pathname.
+ * If the final component of path name, save information
+ * in the cache as to where the entry was found.
*/
- bcopy((caddr_t)ep, (caddr_t)&u.u_dent, DIRSIZ(ep));
- brelse(bp);
- bp = NULL;
+ if (*ndp->ni_next == '\0' && flag == LOOKUP)
+ dp->i_diroff = ndp->ni_ufs.ufs_offset &~ (DIRBLKSIZ - 1);
/*
* If deleting, and at end of pathname, return
* parameters which can be used to remove file.
- * Note that in this case we return the directory
- * inode, not the inode of the file being deleted.
+ * If the wantparent flag isn't set, we return only
+ * the directory (in ndp->ni_dvp), otherwise we go
+ * on and lock the inode, being careful with ".".
*/
- if (flag == 2 && *cp == 0) {
+ if (flag == DELETE && *ndp->ni_next == 0) {
/*
* Write access to directory required to delete files.
*/
- if (access(dp, IWRITE))
- goto bad;
+ if (error = ufs_access(vdp, VWRITE, ndp->ni_cred, p))
+ return (error);
/*
- * Return pointer to current entry in u.u_offset,
+ * Return pointer to current entry in ndp->ni_ufs.ufs_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().
+ * is a previous entry in this block) in ndp->ni_ufs.ufs_count.
+ * Save directory inode pointer in ndp->ni_dvp for dirremove().
*/
- if ((u.u_offset&(DIRBLKSIZ-1)) == 0)
- u.u_count = 0;
+ if ((ndp->ni_ufs.ufs_offset&(DIRBLKSIZ-1)) == 0)
+ ndp->ni_ufs.ufs_count = 0;
else
- u.u_count = u.u_offset - prevoff;
- brelse(nbp);
- u.u_pdir = dp; /* for dirremove() */
- return (dp);
+ ndp->ni_ufs.ufs_count =
+ ndp->ni_ufs.ufs_offset - prevoff;
+ if (dp->i_number == ndp->ni_ufs.ufs_ino) {
+ VREF(vdp);
+ ndp->ni_vp = vdp;
+ return (0);
+ }
+ if (error = VOP_VGET(vdp, ndp->ni_ufs.ufs_ino, &tdp))
+ return (error);
+ /*
+ * If directory is "sticky", then user must own
+ * the directory, or the file in it, else she
+ * may not delete it (unless she's root). This
+ * implements append-only directories.
+ */
+ if ((dp->i_mode & ISVTX) &&
+ ndp->ni_cred->cr_uid != 0 &&
+ ndp->ni_cred->cr_uid != dp->i_uid &&
+ VTOI(tdp)->i_uid != ndp->ni_cred->cr_uid) {
+ vput(tdp);
+ return (EPERM);
+ }
+ ndp->ni_vp = tdp;
+ if (!lockparent)
+ IUNLOCK(dp);
+ return (0);
}
/*
- * Special handling for ".." allowing chdir out of mounted
- * file system: indirect .. in root inode to reevaluate
- * in directory file system was mounted on.
+ * 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.
*/
- if (u.u_dent.d_name[0] == '.' && u.u_dent.d_name[1] == '.' &&
- u.u_dent.d_name[2] == '\0') {
- 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;
- }
- }
+ if (flag == RENAME && wantparent && *ndp->ni_next == 0) {
+ if (error = ufs_access(vdp, VWRITE, ndp->ni_cred, p))
+ return (error);
+ /*
+ * Careful about locking second inode.
+ * This can only occur if the target is ".".
+ */
+ if (dp->i_number == ndp->ni_ufs.ufs_ino)
+ return (EISDIR);
+ if (error = VOP_VGET(vdp, ndp->ni_ufs.ufs_ino, &tdp))
+ return (error);
+ ndp->ni_vp = tdp;
+ ndp->ni_nameiop |= SAVENAME;
+ if (!lockparent)
+ IUNLOCK(dp);
+ return (0);
}
/*
- * Check for symbolic link, which may require us
- * to massage the name before we continue translation.
- * To avoid deadlock have to unlock the current directory,
- * but don't iput it because we may need it again (if
- * the symbolic link is relative to .). Instead save
- * it (unlocked) as pdp.
+ * Step through the translation in the name. We do not `iput' the
+ * directory because we may need it again if a 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;
- iunlock(pdp);
- dp = iget(dp->i_dev, fs, u.u_dent.d_ino);
- if (dp == NULL)
- goto bad2;
- fs = dp->i_fs;
-
- /*
- * Check for symbolic link
- */
- if ((dp->i_mode & IFMT) == IFLNK && (follow || *cp == '/')) {
- int pathlen = strlen(cp) + 1;
- int bn;
-
- if (dp->i_size + pathlen >= MAXPATHLEN - 1 ||
- ++nlink > MAXSYMLINKS) {
- u.u_error = ELOOP;
- goto bad2;
- }
- bcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen);
- u.u_segflg = 1;
- u.u_base = nbp->b_un.b_addr;
- u.u_count = dp->i_size;
- u.u_offset = 0;
- readi(dp);
- if (u.u_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);
+ if (ndp->ni_isdotdot) {
+ IUNLOCK(pdp); /* race to get the inode */
+ if (error = VOP_VGET(vdp, ndp->ni_ufs.ufs_ino, &tdp)) {
+ ILOCK(pdp);
+ return (error);
}
- fs = dp->i_fs;
- goto dirloop;
+ if (lockparent && *ndp->ni_next == '\0')
+ ILOCK(pdp);
+ ndp->ni_vp = tdp;
+ } else if (dp->i_number == ndp->ni_ufs.ufs_ino) {
+ VREF(vdp); /* we want ourself, ie "." */
+ ndp->ni_vp = vdp;
+ } else {
+ if (error = VOP_VGET(vdp, ndp->ni_ufs.ufs_ino, &tdp))
+ return (error);
+ if (!lockparent || *ndp->ni_next != '\0')
+ IUNLOCK(pdp);
+ ndp->ni_vp = tdp;
}
- irele(pdp);
/*
- * Not a symbolic link. If more pathname,
- * continue at next component, else return.
+ * Insert name into cache if appropriate.
*/
- if (*cp == '/') {
- while (*cp == '/')
- cp++;
- goto dirloop;
- }
- brelse(nbp);
- return (dp);
-bad2:
- irele(pdp);
-bad:
- if (bp)
- brelse(bp);
- if (dp)
- iput(dp);
- brelse(nbp);
- return (NULL);
+ if (ndp->ni_makeentry)
+ cache_enter(ndp);
+ return (0);
}
-dirbad(ip, how)
+void
+ufs_dirbad(ip, offset, how)
struct inode *ip;
+ off_t offset;
char *how;
{
+ struct mount *mp;
- printf("%s: bad dir ino %d at offset %d: %s\n",
- ip->i_fs->fs_fsmnt, ip->i_number, u.u_offset, how);
+ mp = ITOV(ip)->v_mount;
+ (void)printf("%s: bad dir ino %d at offset %d: %s\n",
+ mp->mnt_stat.f_mntonname, ip->i_number, offset, how);
+ if ((mp->mnt_stat.f_flags & MNT_RDONLY) == 0)
+ panic("bad dir");
}
-dirbadname(ep)
+/*
+ * Do consistency checking on a directory entry:
+ * record length must be multiple of 4
+ * entry must fit in rest of its DIRBLKSIZ block
+ * record must be large enough to contain entry
+ * name is not longer than MAXNAMLEN
+ * name must be as long as advertised, and null terminated
+ */
+int
+ufs_dirbadentry(ep, entryoffsetinblock)
register struct direct *ep;
+ int entryoffsetinblock;
{
- register char *cp;
register int i;
+ if ((ep->d_reclen & 0x3) != 0 ||
+ ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
+ ep->d_reclen < DIRSIZ(ep) || ep->d_namlen > MAXNAMLEN) {
+ /*return (1); */
+ printf("First bad\n");
+ goto bad;
+ }
for (i = 0; i < ep->d_namlen; i++)
- if (ep->d_name[i] == 0)
- return (1);
+ if (ep->d_name[i] == '\0') {
+ /*return (1); */
+ printf("Second bad\n");
+ goto bad;
+ }
+ if (ep->d_name[i])
+ goto bad;
return (ep->d_name[i]);
+bad:
+printf("ufs_dirbadentry: jumping out: reclen: %d namlen %d ino %d name %s\n",
+ ep->d_reclen, ep->d_namlen, ep->d_ino, ep->d_name );
+ return(1);
}
/*
* 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.
+ * that it left in nameidata. The argument ip is the inode which the new
+ * directory entry will refer to. The nameidata field ndp->ni_dvp is a
+ * pointer to the directory to be written, which was left locked by namei.
+ * Remaining parameters (ndp->ni_ufs.ufs_offset, ndp->ni_ufs.ufs_count)
+ * indicate how the space for the new entry is to be obtained.
*/
-direnter(ip)
+int
+ufs_direnter(ip, ndp)
struct inode *ip;
+ register struct nameidata *ndp;
{
register struct direct *ep, *nep;
- struct fs *fs;
+ register struct inode *dp;
+ register struct vnode *dvp;
struct buf *bp;
- int loc, dsize, freespace, newentrysize;
+ struct direct newdir;
+ struct iovec aiov;
+ struct uio auio;
+ u_int dsize;
+ int error, loc, newentrysize, spacefree;
char *dirbuf;
- u.u_dent.d_ino = ip->i_number;
- u.u_segflg = 1;
- newentrysize = DIRSIZ(&u.u_dent);
- if (u.u_count == 0) {
+#ifdef DIAGNOSTIC
+ if ((ndp->ni_nameiop & SAVENAME) == 0)
+ panic("direnter: missing name");
+#endif
+ dvp = ndp->ni_dvp;
+ dp = VTOI(dvp);
+ newdir.d_ino = ip->i_number;
+ newdir.d_namlen = ndp->ni_namelen;
+ bcopy(ndp->ni_ptr, newdir.d_name, (unsigned)ndp->ni_namelen + 1);
+ newentrysize = DIRSIZ(&newdir);
+ if (ndp->ni_ufs.ufs_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 ndp->ni_ufs.ufs_count is 0, then namei could find no
+ * space in the directory. Here, ndp->ni_ufs.ufs_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))
+ if (ndp->ni_ufs.ufs_offset & (DIRBLKSIZ - 1))
panic("wdir: newblk");
- u.u_dent.d_reclen = DIRBLKSIZ;
- u.u_count = newentrysize;
- u.u_base = (caddr_t)&u.u_dent;
- u.u_segflg = 1;
- writei(u.u_pdir);
- iput(u.u_pdir);
- return;
+ auio.uio_offset = ndp->ni_ufs.ufs_offset;
+ newdir.d_reclen = DIRBLKSIZ;
+ auio.uio_resid = newentrysize;
+ aiov.iov_len = newentrysize;
+ aiov.iov_base = (caddr_t)&newdir;
+ auio.uio_iov = &aiov;
+ auio.uio_iovcnt = 1;
+ auio.uio_rw = UIO_WRITE;
+ auio.uio_segflg = UIO_SYSSPACE;
+ auio.uio_procp = (struct proc *)0;
+ error = VOP_WRITE(dvp, &auio, IO_SYNC, ndp->ni_cred);
+ if (DIRBLKSIZ >
+ VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
+ /* XXX should grow with balloc() */
+ panic("ufs_direnter: frag size");
+ else if (!error) {
+ dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
+ dp->i_flag |= ICHG;
+ }
+ 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.
+ * If ndp->ni_ufs.ufs_count is non-zero, then namei found space
+ * for the new entry in the range ndp->ni_ufs.ufs_offset to
+ * ndp->ni_ufs.ufs_offset + ndp->ni_ufs.ufs_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.
+ *
+ * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
*/
- if (u.u_offset+u.u_count > u.u_pdir->i_size) {
-/*ZZ*/ if (((u.u_offset+u.u_count-1)&~(DIRBLKSIZ-1)) !=
-/*ZZ*/ ((u.u_pdir->i_size-1)&~(DIRBLKSIZ-1))) {
-/*ZZ*/ panic("wdir: span");
-/*ZZ*/ }
- u.u_pdir->i_size = u.u_offset + u.u_count;
- }
-
+ if (ndp->ni_ufs.ufs_offset + ndp->ni_ufs.ufs_count > dp->i_size)
+ dp->i_size = ndp->ni_ufs.ufs_offset + ndp->ni_ufs.ufs_count;
/*
- * Get the block containing the space for the new directory
- * entry.
+ * Get the block containing the space for the new directory entry.
*/
- bp = blkatoff(u.u_pdir, u.u_offset, (char **)&dirbuf);
- if (bp == 0)
- return;
-
+ if (error = VOP_BLKATOFF(dvp, ndp->ni_ufs.ufs_offset, &dirbuf, &bp))
+ return (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.
+ * 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 ndp->ni_ufs.ufs_offset to
+ * ndp->ni_ufs.ufs_offset + ndp->ni_ufs.ufs_count would yield the
+ * space.
*/
ep = (struct direct *)dirbuf;
dsize = DIRSIZ(ep);
- freespace = ep->d_reclen - dsize;
- for (loc = ep->d_reclen; loc < u.u_count; ) {
+ spacefree = ep->d_reclen - dsize;
+ for (loc = ep->d_reclen; loc < ndp->ni_ufs.ufs_count; ) {
nep = (struct direct *)(dirbuf + loc);
if (ep->d_ino) {
/* trim the existing slot */
ep = (struct direct *)((char *)ep + dsize);
} else {
/* overwrite; nothing there; header is ours */
- freespace += dsize;
+ spacefree += dsize;
}
dsize = DIRSIZ(nep);
- freespace += nep->d_reclen - dsize;
+ spacefree += nep->d_reclen - dsize;
loc += nep->d_reclen;
-/*ZZ*/if((loc&~0x1ff)!=(loc+nep->d_reclen-1&~0x1ff))
-/*ZZ*/printf("wdir: compact loc %d reclen %d (dir %s/%d)\n",loc,nep->d_reclen,
-/*ZZ*/u.u_pdir->i_fs->fs_fsmnt,u.u_pdir->i_number);
- bcopy(nep, ep, dsize);
+ bcopy((caddr_t)nep, (caddr_t)ep, dsize);
}
/*
* Update the pointer fields in the previous entry (if any),
* copy in the new entry, and write out the block.
*/
if (ep->d_ino == 0) {
- if (freespace + dsize < newentrysize)
+ if (spacefree + dsize < newentrysize)
panic("wdir: compact1");
-/*ZZ*/if(freespace+dsize>512)panic("wdir: compact screwup");
- u.u_dent.d_reclen = freespace + dsize;
+ newdir.d_reclen = spacefree + dsize;
} else {
- if (freespace < newentrysize)
+ if (spacefree < newentrysize)
panic("wdir: compact2");
- u.u_dent.d_reclen = freespace;
-/*ZZ*/if ((((char *)ep-bp->b_un.b_addr)&0x1ff)+dsize>512) panic("wdir: reclen");
+ newdir.d_reclen = spacefree;
ep->d_reclen = dsize;
ep = (struct direct *)((char *)ep + dsize);
}
-/*ZZ*/if((((char*)ep-bp->b_un.b_addr)&0x1ff)+u.u_dent.d_reclen>512)panic("wdir: botch");
- bcopy(&u.u_dent, ep, newentrysize);
- bwrite(bp);
- u.u_pdir->i_flag |= IUPD|ICHG;
- iput(u.u_pdir);
+ bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize);
+ error = VOP_BWRITE(bp);
+ dp->i_flag |= IUPD|ICHG;
+ if (!error && ndp->ni_ufs.ufs_endoff &&
+ ndp->ni_ufs.ufs_endoff < dp->i_size)
+ error = VOP_TRUNCATE(dvp, (u_long)ndp->ni_ufs.ufs_endoff,
+ IO_SYNC);
+ return (error);
}
-dirremove()
+/*
+ * Remove a directory entry after a call to namei, using
+ * the parameters which it left in nameidata. The entry
+ * ni_ufs.ufs_offset contains the offset into the directory of the
+ * entry to be eliminated. The ni_ufs.ufs_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 is not 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.
+ */
+int
+ufs_dirremove(ndp)
+ register struct nameidata *ndp;
{
- register struct inode *dp = u.u_pdir;
- register struct fs *fs = dp->i_fs;
- register struct buf *bp;
+ register struct inode *dp;
struct direct *ep;
+ struct buf *bp;
+ int error;
- if (u.u_count == 0) {
+ dp = VTOI(ndp->ni_dvp);
+ if (ndp->ni_ufs.ufs_count == 0) {
/*
* First entry in block: set d_ino to zero.
*/
-/*ZZ*/if(u.u_offset&0x1ff)printf("missed dir compact dir %s/%d off %d file %s\n"
-/*ZZ*/,dp->i_fs->fs_fsmnt,dp->i_number,u.u_offset,u.u_dent.d_name);
- u.u_base = (caddr_t)&u.u_dent;
- u.u_count = DIRSIZ(&u.u_dent);
- u.u_segflg = 1;
- u.u_dent.d_ino = 0;
- writei(dp);
- } else {
+ if (error = VOP_BLKATOFF(ndp->ni_dvp, ndp->ni_ufs.ufs_offset,
+ (char **)&ep, &bp))
+ return (error);
+ ep->d_ino = 0;
+ error = VOP_BWRITE(bp);
+ dp->i_flag |= IUPD|ICHG;
+ return (error);
+ }
+ /*
+ * Collapse new free space into previous entry.
+ */
+ if (error = VOP_BLKATOFF(ndp->ni_dvp,
+ ndp->ni_ufs.ufs_offset - ndp->ni_ufs.ufs_count, (char **)&ep, &bp))
+ return (error);
+ ep->d_reclen += ndp->ni_ufs.ufs_reclen;
+ error = VOP_BWRITE(bp);
+ dp->i_flag |= IUPD|ICHG;
+ return (error);
+}
+
+/*
+ * 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.
+ */
+int
+ufs_dirrewrite(dp, ip, ndp)
+ struct inode *dp, *ip;
+ struct nameidata *ndp;
+{
+ struct buf *bp;
+ struct direct *ep;
+ int error;
+
+ if (error = VOP_BLKATOFF(ITOV(dp), ndp->ni_ufs.ufs_offset,
+ (char **)&ep, &bp))
+ return (error);
+ ep->d_ino = ip->i_number;
+ error = VOP_BWRITE(bp);
+ dp->i_flag |= IUPD|ICHG;
+ return (error);
+}
+
+/*
+ * 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.
+ */
+int
+ufs_dirempty(ip, parentino, cred)
+ register struct inode *ip;
+ ino_t parentino;
+ struct ucred *cred;
+{
+ 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 = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
+ UIO_SYSSPACE, IO_NODELOCKED, cred, &count, (struct proc *)0);
/*
- * Collapse new free space into previous entry.
+ * Since we read MINDIRSIZ, residual must
+ * be 0 unless we're at end of file.
*/
- bp = blkatoff(dp, u.u_offset - u.u_count, (char **)&ep);
- if (bp == 0)
+ if (error || count != 0)
return (0);
- ep->d_reclen += u.u_dent.d_reclen;
-/*ZZ*/if((((char *)ep - bp->b_un.b_addr)&0x1ff)+u.u_dent.d_reclen > 512)
-/*ZZ*/ panic("unlink: reclen");
- bwrite(bp);
- dp->i_flag |= IUPD|ICHG;
+ /* avoid infinite loops */
+ if (dp->d_reclen == 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)
+ continue;
+ if (dp->d_name[1] == '.' && dp->d_ino == parentino)
+ continue;
+ return (0);
}
return (1);
}
/*
- * 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.
+ * 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.
*/
-struct buf *
-blkatoff(ip, offset, res)
- struct inode *ip;
- off_t offset;
- char **res;
+int
+ufs_checkpath(source, target, cred)
+ struct inode *source, *target;
+ struct ucred *cred;
{
- register struct fs *fs = ip->i_fs;
- int lbn = lblkno(fs, offset);
- int base = blkoff(fs, offset);
- int bsize = blksize(fs, ip, lbn);
- int 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);
+ struct dirtemplate dirbuf;
+ register struct inode *ip;
+ struct vnode *vp;
+ int error, rootino;
+
+ ip = target;
+ if (ip->i_number == source->i_number) {
+ error = EEXIST;
+ goto out;
+ }
+ rootino = ROOTINO;
+ error = 0;
+ if (ip->i_number == rootino)
+ goto out;
+
+ for (;;) {
+ if ((ip->i_mode&IFMT) != IFDIR) {
+ error = ENOTDIR;
+ break;
+ }
+ vp = ITOV(ip);
+ error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
+ sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
+ IO_NODELOCKED, cred, (int *)0, (struct proc *)0);
+ if (error != 0)
+ break;
+ if (dirbuf.dotdot_namlen != 2 ||
+ dirbuf.dotdot_name[0] != '.' ||
+ dirbuf.dotdot_name[1] != '.') {
+ error = ENOTDIR;
+ break;
+ }
+ if (dirbuf.dotdot_ino == source->i_number) {
+ error = EINVAL;
+ break;
+ }
+ if (dirbuf.dotdot_ino == rootino)
+ break;
+ ufs_iput(ip);
+ if (error = VOP_VGET(vp, dirbuf.dotdot_ino, &vp))
+ break;
+ ip = VTOI(vp);
}
- if (res)
- *res = bp->b_un.b_addr + base;
- return (bp);
+
+out:
+ if (error == ENOTDIR)
+ printf("checkpath: .. not a directory\n");
+ if (ip != NULL)
+ ufs_iput(ip);
+ return (error);
}