-/* vfs_lookup.c 4.16 82/06/07 */
-
-/* merged into kernel: @(#)nami.c 2.3 4/8/82 */
+/* vfs_lookup.c 4.24 82/08/24 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/user.h"
#include "../h/buf.h"
#include "../h/conf.h"
+#include "../h/uio.h"
+struct buf *blkatoff();
+int dirchk = 1;
/*
- * Convert a pathname into a pointer to
- * a locked inode.
+ * Convert a pathname into a pointer to a locked inode,
+ * with side effects usable in creating and removing files.
+ * 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 (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.
+ *
+ * Overall outline:
*
- * func = function called to get next char of name
- * &uchar if name is in user space
- * &schar if name is in system space
- * flag = 0 if name is sought
- * 1 if name is to be created
- * 2 if name is to be deleted
- * follow = 1 if links are to be followed at the end of the name
+ * 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
+ * search for name in directory, to found or notfound
+ * notfound:
+ * if creating, return locked inode, leaving information on avail. 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
*/
struct inode *
namei(func, flag, follow)
int (*func)(), flag, follow;
{
- register struct inode *dp;
- register char *cp;
- register struct buf *bp, *nbp;
- register struct direct *ep;
- register struct fs *fs;
- struct inode *pdp;
- enum {NONE, COMPACT, FOUND} slot;
- int entryfree, entrysize;
- int spccnt, size, newsize;
- int loc, prevoff, curoff;
- int i, nlink, bsize;
- unsigned pathlen;
- daddr_t lbn, bn;
- dev_t d;
+ 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 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 dirsize;
+ 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;
/*
- * allocate name buffer; copy name
+ * Get a buffer for the name to be translated, and copy the
+ * name into the buffer.
*/
nbp = geteblk(MAXPATHLEN);
- nlink = 0;
- for (i = 0, cp = nbp->b_un.b_addr; *cp = (*func)(); i++) {
- if ((*cp & 0377) == ('/'|0200)) {
+ for (cp = nbp->b_un.b_addr; *cp = (*func)(); ) {
+ if ((*cp&0377) == ('/'|0200) || (*cp&0200) && flag != 2) {
u.u_error = EPERM;
- break;
+ goto bad;
}
-#ifdef notdef
- if (*cp++ & 0200 && flag == 1 ||
- cp >= nbp->b_un.b_addr + MAXPATHLEN) {
-#else
cp++;
if (cp >= nbp->b_un.b_addr + MAXPATHLEN) {
-#endif
u.u_error = ENOENT;
- break;
+ goto bad;
}
}
- if (u.u_error) {
- brelse(nbp);
- return (NULL);
- }
- cp = nbp->b_un.b_addr;
+ if (u.u_error)
+ goto bad;
+
/*
- * If name starts with '/' start from
- * root; otherwise start from current dir.
+ * Get starting directory.
*/
- dp = u.u_cdir;
+ 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++;
- fs = dp->i_fs;
- newsize = 0;
+ u.u_pdir = (struct inode *)0xc0000000; /* illegal */
+
+ /*
+ * 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:
/*
- * dp must be a directory and
- * must have X permission.
- * cp is a path name relative to that directory.
+ * Check accessiblity of directory.
*/
- if ((dp->i_mode&IFMT) != IFDIR)
+ if ((dp->i_mode&IFMT) != IFDIR) {
u.u_error = ENOTDIR;
- (void) access(dp, IEXEC);
+ goto bad;
+ }
+ if (access(dp, IEXEC))
+ goto bad;
+
dirloop2:
- for (i = 0; *cp != '\0' && *cp != '/'; cp++) {
-#ifdef notdef
+ /*
+ * Copy next component of name to u.u_dent.
+ */
+ for (i = 0; *cp != 0 && *cp != '/'; cp++) {
if (i >= MAXNAMLEN) {
u.u_error = ENOENT;
- break;
- }
- u.u_dent.d_name[i] = *cp;
-#else
- if (i < MAXNAMLEN) {
- u.u_dent.d_name[i] = *cp;
- i++;
+ goto bad;
}
-#endif
- }
- if (u.u_error) {
- iput(dp);
- brelse(nbp);
- return (NULL);
+ u.u_dent.d_name[i++] = *cp;
}
u.u_dent.d_namlen = i;
- u.u_dent.d_name[i] = '\0';
- newsize = DIRSIZ(&u.u_dent);
- u.u_pdir = dp;
- if (u.u_dent.d_name[0] == '\0') { /* null name, e.g. "/" or "" */
- if (flag != 0) {
+ 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;
- iput(dp);
- dp = NULL;
+ goto bad;
}
- u.u_offset = 0;
- u.u_count = newsize;
brelse(nbp);
return (dp);
}
+
/*
- * set up to search a directory
+ * 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.
*/
- if (flag == 1)
- slot = NONE;
- else
- slot = FOUND;
+ slotstatus = FOUND;
+ if (flag == 1 && *cp == 0) {
+ slotstatus = NONE;
+ slotfreespace = 0;
+ slotneeded = DIRSIZ(&u.u_dent);
+ }
+
+ dirsize = roundup(dp->i_size, DIRBLKSIZ);
u.u_offset = 0;
- u.u_segflg = 1;
- bp = NULL;
- spccnt = 0;
- loc = 0;
- while (u.u_offset < dp->i_size) {
- /*
- * check to see if enough space has been accumulated to make
- * an entry by compaction. Reset the free space counter each
- * time a directory block is crossed.
- */
- if (slot == NONE) {
- if (spccnt >= newsize) {
- slot = COMPACT;
- entrysize = u.u_offset - entryfree;
- } else if (loc % DIRBLKSIZ == 0) {
- entryfree = NULL;
- spccnt = 0;
- }
- }
+ while (u.u_offset < dirsize) {
/*
* If offset is on a block boundary,
* read the next directory block.
if (blkoff(fs, u.u_offset) == 0) {
if (bp != NULL)
brelse(bp);
- lbn = (daddr_t)lblkno(fs, u.u_offset);
- bsize = blksize(fs, dp, lbn);
- if ((bn = bmap(dp, lbn, B_READ)) < 0) {
- printf("hole in dir: %s i = %d\n",
- fs->fs_fsmnt, dp->i_number);
- if (fs->fs_ronly != 0 ||
- (bn = bmap(dp, lbn, B_WRITE, bsize)) < 0) {
- u.u_offset += bsize;
- bp = NULL;
- continue;
- }
- }
- bp = bread(dp->i_dev, fsbtodb(fs, bn), bsize);
- if (bp->b_flags & B_ERROR) {
- brelse(bp);
- iput(dp);
- brelse(nbp);
- return (NULL);
- }
- loc = 0;
- } else {
- loc += ep->d_reclen;
+ bp = blkatoff(dp, u.u_offset, (char **)0);
+ if (bp == 0)
+ goto bad;
+ entryoffsetinblock = 0;
}
+
/*
- * calculate the next directory entry and run
- * some rudimentary bounds checks to make sure
- * that it is reasonable. If the check fails
- * resync at the beginning of the next directory
- * block.
+ * 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 + loc);
- i = DIRBLKSIZ - (loc & (DIRBLKSIZ - 1));
- if (ep->d_reclen <= 0 || ep->d_reclen > i) {
- loc += i;
+ 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 hole has not yet been found,
+ * 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 (slot != FOUND) {
- size = ep->d_reclen;
+ if (slotstatus != FOUND) {
+ int size = ep->d_reclen;
+
if (ep->d_ino != 0)
size -= DIRSIZ(ep);
if (size > 0) {
- if (size >= newsize) {
- slot = FOUND;
- entryfree = u.u_offset;
- entrysize = DIRSIZ(ep) + newsize;
+ 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;
+ }
}
- if (entryfree == NULL)
- entryfree = u.u_offset;
- spccnt += size;
}
}
+
/*
- * String compare the directory entry
- * and the current component.
- * If they do not match, continue to the next entry.
+ * Check for a name match.
*/
- prevoff = curoff;
- curoff = u.u_offset;
+ 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;
- if (ep->d_ino == 0)
- continue;
- if (ep->d_namlen != u.u_dent.d_namlen)
- continue;
- if (bcmp(u.u_dent.d_name, ep->d_name, ep->d_namlen))
- continue;
+ entryoffsetinblock += ep->d_reclen;
+ }
+/* notfound: */
+ /*
+ * If creating, and at end of pathname and current
+ * directory has not been removed, then can consider allowing
+ * file to be created.
+ */
+ if (flag == 1 && *cp == 0 && dp->i_nlink != 0) {
/*
- * Here a component matched in a directory.
- * If there is more pathname, go back to
- * dirloop, otherwise return.
+ * Access for write is interpreted as allowing
+ * creation of files in the directory.
*/
- bcopy((caddr_t)ep, (caddr_t)&u.u_dent, DIRSIZ(ep));
- brelse(bp);
- if (flag == 2 && *cp == '\0') {
- brelse(nbp);
- if (access(dp, IWRITE)) {
- iput(dp);
- return (NULL);
- }
- if (curoff % DIRBLKSIZ == 0) {
- u.u_offset = curoff;
- u.u_count = 0;
- return (dp);
- }
- u.u_offset = prevoff;
- u.u_count = DIRSIZ((struct direct *)
- (bp->b_un.b_addr + blkoff(fs, prevoff)));
- return (dp);
- }
+ if (access(dp, IWRITE))
+ goto bad;
/*
- * Special handling for ".."
+ * 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 (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;
- }
- }
- }
- d = dp->i_dev;
- pdp = dp;
- iunlock(pdp);
- dp = iget(d, fs, u.u_dent.d_ino);
- if (dp == NULL) {
- irele(pdp);
- brelse(nbp);
- return (NULL);
+ if (slotstatus == NONE)
+ u.u_count = 0;
+ else {
+ u.u_offset = slotoffset;
+ u.u_count = slotsize;
}
- fs = dp->i_fs;
+ dp->i_flag |= IUPD|ICHG;
+ if (bp)
+ brelse(bp);
+ brelse(nbp);
/*
- * Check for symbolic link
+ * 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.
*/
- if ((dp->i_mode & IFMT) == IFLNK && (follow || *cp == '/')) {
- pathlen = strlen(cp) + 1;
- if (dp->i_size + pathlen >= MAXPATHLEN - 1 ||
- ++nlink > MAXSYMLINKS) {
- u.u_error = ELOOP;
- irele(pdp);
- iput(dp);
- brelse(nbp);
- return (NULL);
- }
- bcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen);
- bn = bmap(dp, (daddr_t)0, B_READ);
- if (bn < 0) {
- printf("hole in symlink: %s i = %d\n",
- fs->fs_fsmnt, dp->i_number);
- irele(pdp);
- iput(dp);
- brelse(nbp);
- return (NULL);
- }
- bp = bread(dp->i_dev, fsbtodb(fs, bn),
- (int)blksize(fs, dp, (daddr_t)0));
- if (bp->b_flags & B_ERROR) {
- brelse(bp);
- irele(pdp);
+ u.u_pdir = dp;
+ return (NULL);
+ }
+ u.u_error = ENOENT;
+ goto bad;
+found:
+ /*
+ * 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; 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.
+ * Note that in this case we return the directory
+ * inode, not the inode of the file being deleted.
+ */
+ if (flag == 2 && *cp == 0) {
+ /*
+ * Write access to directory required to delete files.
+ */
+ if (access(dp, IWRITE))
+ goto bad;
+ /*
+ * 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().
+ */
+ if ((u.u_offset&(DIRBLKSIZ-1)) == 0)
+ u.u_count = 0;
+ else
+ u.u_count = u.u_offset - prevoff;
+ brelse(nbp);
+ u.u_pdir = dp; /* for dirremove() */
+ 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.
+ */
+ 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);
- brelse(nbp);
- return (NULL);
- }
- bcopy(bp->b_un.b_addr, nbp->b_un.b_addr,
- (unsigned)dp->i_size);
- brelse(bp);
- cp = nbp->b_un.b_addr;
- iput(dp);
- if (*cp == '/') {
- irele(pdp);
- while (*cp == '/')
- cp++;
- if ((dp = u.u_rdir) == NULL)
- dp = rootdir;
+ dp = mount[i].m_inodp;
ilock(dp);
dp->i_count++;
- } else {
- dp = pdp;
- ilock(dp);
+ fs = dp->i_fs;
+ cp -= 2; /* back over .. */
+ goto dirloop2;
}
- fs = dp->i_fs;
- goto dirloop;
}
- irele(pdp);
+ }
+
+ /*
+ * 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.
+ */
+ 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 == '/')) {
+ u_int pathlen = strlen(cp) + 1;
+
+ 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_error =
+ rdwri(UIO_READ, dp, nbp->b_un.b_addr, dp->i_size,
+ 0, 1, (int *)0);
+ if (u.u_error)
+ goto bad2;
+ cp = nbp->b_un.b_addr;
+ iput(dp);
if (*cp == '/') {
+ irele(pdp);
while (*cp == '/')
cp++;
- goto dirloop;
+ if ((dp = u.u_rdir) == NULL)
+ dp = rootdir;
+ ilock(dp);
+ dp->i_count++;
+ } else {
+ dp = pdp;
+ ilock(dp);
}
- /*
- * End of path, so return name matched.
- */
- u.u_offset -= ep->d_reclen;
- u.u_count = newsize;
- brelse(nbp);
- return (dp);
+ fs = dp->i_fs;
+ goto dirloop;
}
+ irele(pdp);
+
/*
- * Search failed.
- * Report what is appropriate as per flag.
+ * Not a symbolic link. If more pathname,
+ * continue at next component, else return.
*/
- if (bp != NULL)
- brelse(bp);
- if (flag == 1 && *cp == '\0' && dp->i_nlink != 0) {
- brelse(nbp);
- if (access(dp, IWRITE)) {
- iput(dp);
- return (NULL);
- }
- if (slot == NONE) {
- u.u_count = 0;
- } else {
- u.u_offset = entryfree;
- u.u_count = entrysize;
- }
- dp->i_flag |= IUPD|ICHG;
- return (NULL);
+ if (*cp == '/') {
+ while (*cp == '/')
+ cp++;
+ goto dirloop;
}
- u.u_error = ENOENT;
- iput(dp);
+ brelse(nbp);
+ return (dp);
+bad2:
+ irele(pdp);
+bad:
+ if (bp)
+ brelse(bp);
+ if (dp)
+ iput(dp);
brelse(nbp);
return (NULL);
}
-/*
- * Return the next character from the
- * kernel string pointed at by dirp.
- */
-schar()
+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;
- return (*u.u_dirp++ & 0377);
+ for (i = 0; i < ep->d_namlen; i++)
+ if (ep->d_name[i] == 0)
+ return (1);
+ return (ep->d_name[i]);
}
/*
- * Return the next character from the
- * user string pointed at by dirp.
+ * 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.
*/
-uchar()
+direnter(ip)
+ struct inode *ip;
{
- register c;
+ register struct direct *ep, *nep;
+ struct buf *bp;
+ int loc, freespace;
+ u_int dsize, newentrysize;
+ char *dirbuf;
- c = fubyte(u.u_dirp++);
- if (c == -1) {
- u.u_error = EFAULT;
- c = 0;
+ 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;
+ (void) rdwri(UIO_WRITE, u.u_pdir, (caddr_t)&u.u_dent, newentrysize,
+ u.u_offset, 1, (int *)0);
+ iput(u.u_pdir);
+ return;
}
- return (c);
+
+ /*
+ * 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) {
+/*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;
+ }
+
+ /*
+ * 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;
+
+ /*
+ * 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);
+ freespace = 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 */
+ freespace += dsize;
+ }
+ dsize = DIRSIZ(nep);
+ freespace += 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((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)
+ panic("wdir: compact1");
+/*ZZ*/if(freespace+dsize>512)panic("wdir: compact screwup");
+ u.u_dent.d_reclen = freespace + dsize;
+ } else {
+ if (freespace < 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");
+ 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);
}
-#ifndef vax
-bcmp(s1, s2, len)
- register char *s1, *s2;
- register int len;
+dirremove()
{
+ register struct inode *dp = u.u_pdir;
+ register struct buf *bp;
+ struct direct *ep;
- while (--len)
- if (*s1++ != *s2++)
- return (1);
- return (0);
+ if (u.u_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_dent.d_ino = 0;
+ (void) rdwri(UIO_WRITE, dp, (caddr_t)&u.u_dent, 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;
+/*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;
+ }
+ return (1);
}
-strlen(s1)
- register char *s1;
+/*
+ * 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 int len;
+ 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;
- for (len = 0; *s1++ != '\0'; len++)
- /* void */;
- return (len);
+ 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);
}
-#endif