patch-1.3.94 linux/fs/ufs/ufs_namei.c

• Lines: 155
• Date: Mon Apr 22 10:59:39 1996
• Orig file: v1.3.93/linux/fs/ufs/ufs_namei.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/fs/ufs/ufs_namei.c linux/fs/ufs/ufs_namei.c
@@ -0,0 +1,154 @@
+/*
+ *  linux/fs/ufs/ufs_namei.c
+ *
+ * Copyright (C) 1996
+ * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
+ * Laboratory for Computer Science Research Computing Facility
+ * Rutgers, The State University of New Jersey
+ *
+ * $Id: ufs_namei.c,v 1.1 1996/04/21 14:41:15 davem Exp $
+ *
+ */
+
+#include <linux/fs.h>
+
+extern unsigned int ufs_bmap(struct inode * inode, int block); /* XXX */
+
+/*
+ * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
+ * stolen from ext2fs
+ */
+static int ufs_match (int len, const char * const name, struct direct * d)
+{
+	if (!d || len > MAXNAMLEN) /* XXX - name space */
+		return 0;
+	/*
+	 * "" means "." ---> so paths like "/usr/lib//libc.a" work
+	 */
+	if (!len && (d->d_namlen == 1) && (d->d_name[0] == '.') &&
+	   (d->d_name[1] == '\0'))
+		return 1;
+	if (len != d->d_namlen)
+		return 0;
+	return !memcmp(name, d->d_name, len);
+}
+
+/* XXX - this is a mess, especially for endianity */
+int ufs_lookup (struct inode * dir, const char * name, int len,
+	        struct inode ** result)
+{
+	unsigned long int lfragno, fragno;
+	struct buffer_head * bh;
+	struct direct * d;
+
+	/*
+	 * Touching /xyzzy in a filesystem toggles debugging messages.
+	 */
+	if ((len == 5) && !(memcmp(name, "xyzzy", len)) &&
+	    (dir->i_ino == UFS_ROOTINO)) {
+	        dir->i_sb->u.ufs_sb.s_flags ^= UFS_DEBUG;
+	        printk("UFS debugging %s\n",
+	               (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) ?
+	               "on": "off");
+	        return(-ENOENT);
+	}
+
+	/*
+	 * Touching /xyzzy.i in a filesystem toggles debugging for ufs_inode.c.
+	 */
+	if ((len == 7) && !(memcmp(name, "xyzzy.i", len)) &&
+	    (dir->i_ino == UFS_ROOTINO)) {
+	        dir->i_sb->u.ufs_sb.s_flags ^= UFS_DEBUG_INODE;
+	        printk("UFS inode debugging %s\n",
+	               (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG_INODE) ?
+	               "on": "off");
+	        return(-ENOENT);
+	}
+
+	if ((len == 7) && !(memcmp(name, "xyzzy.n", len)) &&
+	    (dir->i_ino == UFS_ROOTINO)) {
+	        dir->i_sb->u.ufs_sb.s_flags ^= UFS_DEBUG_NAMEI;
+	        printk("UFS namei debugging %s\n",
+	               (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG_NAMEI) ?
+	               "on": "off");
+	        return(-ENOENT);
+	}
+
+	if ((len == 7) && !(memcmp(name, "xyzzy.l", len)) &&
+	    (dir->i_ino == UFS_ROOTINO)) {
+	        dir->i_sb->u.ufs_sb.s_flags ^= UFS_DEBUG_LINKS;
+	        printk("UFS symlink debugging %s\n",
+	               (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG_LINKS) ?
+	               "on": "off");
+	        return(-ENOENT);
+	}
+
+	if (dir->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_NAMEI)) {
+	        printk("ufs_lookup: called for ino %lu  name %s\n",
+	               dir->i_ino, name);
+	}
+
+	/* XXX - do I want i_blocks in 512-blocks or 1024-blocks? */
+	for (lfragno = 0; lfragno < (dir->i_blocks)>>1; lfragno++) {
+	        fragno = ufs_bmap(dir, lfragno);
+	        /* XXX - ufs_bmap() call needs error checking */
+	        /* XXX - s_blocksize is actually the UFS frag size */
+	        if (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
+	                printk("ufs_lookup: ino %lu lfragno %lu  fragno %lu\n",
+	                       dir->i_ino, lfragno, fragno);
+	        }
+	        if (fragno == 0) {
+	                /* XXX - bug bug bug */
+	                return(-ENOENT);
+	        }
+	        bh = bread(dir->i_dev, fragno, dir->i_sb->s_blocksize);
+	        if (bh == NULL) {
+	                printk("ufs_lookup: bread failed: ino %lu, lfragno %u",
+	                       dir->i_ino, lfragno);
+	                return(-EIO);
+	        }
+	        d = (struct direct *)(bh->b_data);
+	        while (((char *)d - bh->b_data + d->d_reclen) <=
+	               dir->i_sb->s_blocksize) {
+	                /* XXX - skip block if d_reclen or d_namlen is 0 */
+	                if ((d->d_reclen == 0) || (d->d_namlen == 0)) {
+	                        if (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
+	                                printk("ufs_lookup: skipped space in directory, ino %lu\n",
+	                                       dir->i_ino);
+	                        }
+	                        break;
+	                }
+	                if (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
+	                        printk("lfragno 0x%x  direct d 0x%x  d_ino %u  d_reclen %u  d_namlen %u  d_name `%s'\n",
+	                               lfragno, (unsigned int)d, d->d_ino, d->d_reclen, d->d_namlen, d->d_name);
+	                }
+	                if ((d->d_namlen == len) &&
+	                    /* XXX - don't use strncmp() - see ext2fs */
+	                    (ufs_match(len, name, d))) {
+	                        /* We have a match */
+	                        *result = iget(dir->i_sb, d->d_ino);
+	                        brelse(bh);
+	                        return(0);
+	                } else {
+	                        /* XXX - bounds checking */
+	                        if (dir->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
+	                                printk("ufs_lookup: wanted (%s,%d) got (%s,%d)\n",
+	                                       name, len, d->d_name, d->d_namlen);
+	                        }
+	                }
+	                d = (struct direct *)((char *)d + d->d_reclen);
+	        }
+	        brelse(bh);
+	}
+	return(-ENOENT);
+}
+
+/*
+ * Local Variables: ***
+ * c-indent-level: 8 ***
+ * c-continued-statement-offset: 8 ***
+ * c-brace-offset: -8 ***
+ * c-argdecl-indent: 0 ***
+ * c-label-offset: -8 ***
+ * End: ***
+ */