Import of Linus's Linux 1.1.68

1 files changed, 893 insertions, 0 deletions

diff --git a/fs/ext/namei.c b/fs/ext/namei.c
new file mode 100644
index 000000000..85a411e94
--- /dev/null
+++ b/fs/ext/namei.c
@@ -0,0 +1,893 @@
+/*
+ *  linux/fs/ext/namei.c
+ *
+ *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
+ *
+ *  from
+ *
+ *  linux/fs/minix/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/sched.h>
+#include <linux/ext_fs.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/errno.h>
+
+#include <asm/segment.h>
+
+/*
+ * comment out this line if you want names > EXT_NAME_LEN chars to be
+ * truncated. Else they will be disallowed.
+ */
+/* #define NO_TRUNCATE */
+
+/*
+ * EXT_DIR_PAD defines the directory entries boundaries
+ *
+ * NOTE: It must be a power of 2 and must be greater or equal than 8
+ * because a directory entry needs 8 bytes for its fixed part
+ * (4 bytes for the inode, 2 bytes for the entry length and 2 bytes
+ * for the name length)
+ */
+#define EXT_DIR_PAD 8
+
+/*
+ *
+ * EXT_DIR_MIN_SIZE is the minimal size of a directory entry
+ *
+ * During allocations, a directory entry is split into 2 ones
+ * *ONLY* if the size of the unused part is greater than or 
+ * equal to EXT_DIR_MIN_SIZE
+ */
+#define EXT_DIR_MIN_SIZE 12
+
+/*
+ * ok, we cannot use strncmp, as the name is not in our data space.
+ * Thus we'll have to use ext_match. No big problem. Match also makes
+ * some sanity tests.
+ *
+ * NOTE! unlike strncmp, ext_match returns 1 for success, 0 for failure.
+ */
+static int ext_match(int len,const char * name,struct ext_dir_entry * de)
+{
+	if (!de || !de->inode || len > EXT_NAME_LEN)
+		return 0;
+	/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
+	if (!len && (de->name[0]=='.') && (de->name[1]=='\0'))
+		return 1;
+	if (len != de->name_len)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+/*
+ *	ext_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the cache buffer in which the entry was found, and the entry
+ * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * entry - you'll have to do that yourself if you want to.
+ *
+ * addition for the ext file system : this function returns the previous
+ * and next directory entries in the parameters prev_dir and next_dir
+ */
+static struct buffer_head * ext_find_entry(struct inode * dir,
+	const char * name, int namelen, struct ext_dir_entry ** res_dir,
+	struct ext_dir_entry ** prev_dir, struct ext_dir_entry ** next_dir)
+{
+	long offset;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de;
+
+	*res_dir = NULL;
+	if (!dir)
+		return NULL;
+#ifdef NO_TRUNCATE
+	if (namelen > EXT_NAME_LEN)
+		return NULL;
+#else
+	if (namelen > EXT_NAME_LEN)
+		namelen = EXT_NAME_LEN;
+#endif
+	bh = ext_bread(dir,0,0);
+	if (!bh)
+		return NULL;
+	if (prev_dir)
+		*prev_dir = NULL;
+	if (next_dir)
+		*next_dir = NULL;
+	offset = 0;
+	de = (struct ext_dir_entry *) bh->b_data;
+	while (offset < dir->i_size) {
+		if ((char *)de >= BLOCK_SIZE+bh->b_data) {
+			brelse(bh);
+			bh = NULL;
+			bh = ext_bread(dir,offset>>BLOCK_SIZE_BITS,0);
+			if (!bh)
+				continue;
+			de = (struct ext_dir_entry *) bh->b_data;
+			if (prev_dir)
+				*prev_dir = NULL;
+		}
+		if (de->rec_len < 8 || de->rec_len % 8 != 0 ||
+		    de->rec_len < de->name_len + 8 ||
+		    (((char *) de) + de->rec_len-1 >= BLOCK_SIZE+bh->b_data)) {
+			printk ("ext_find_entry: bad dir entry\n");
+			printk ("dev=%d, dir=%ld, offset=%ld, rec_len=%d, name_len=%d\n",
+				dir->i_dev, dir->i_ino, offset, de->rec_len, de->name_len);
+			de = (struct ext_dir_entry *) (bh->b_data+BLOCK_SIZE);
+			offset = ((offset / BLOCK_SIZE) + 1) * BLOCK_SIZE;
+			continue;
+/*			brelse (bh);
+			return NULL; */
+		}
+		if (ext_match(namelen,name,de)) {
+			*res_dir = de;
+			if (next_dir)
+				if (offset + de->rec_len < dir->i_size &&
+				    ((char *)de) + de->rec_len < BLOCK_SIZE+bh->b_data)
+					*next_dir = (struct ext_dir_entry *)
+						((char *) de + de->rec_len);
+				else
+					*next_dir = NULL;
+			return bh;
+		}
+		offset += de->rec_len;
+		if (prev_dir)
+			*prev_dir = de;
+		de = (struct ext_dir_entry *) ((char *) de + de->rec_len);
+	}
+	brelse(bh);
+	return NULL;
+}
+
+int ext_lookup(struct inode * dir,const char * name, int len,
+	struct inode ** result)
+{
+	int ino;
+	struct ext_dir_entry * de;
+	struct buffer_head * bh;
+
+	*result = NULL;
+	if (!dir)
+		return -ENOENT;
+	if (!S_ISDIR(dir->i_mode)) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!(bh = ext_find_entry(dir,name,len,&de,NULL,NULL))) {
+		iput(dir);
+		return -ENOENT;
+	}
+	ino = de->inode;
+	brelse(bh);
+	if (!(*result = iget(dir->i_sb,ino))) {
+		iput(dir);
+		return -EACCES;
+	}
+	iput(dir);
+	return 0;
+}
+
+/*
+ *	ext_add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as ext_find_entry(). It returns NULL if it failed.
+ *
+ * NOTE!! The inode part of 'de' is left at 0 - which means you
+ * may not sleep between calling this and putting something into
+ * the entry, as someone else might have used it while you slept.
+ */
+static struct buffer_head * ext_add_entry(struct inode * dir,
+	const char * name, int namelen, struct ext_dir_entry ** res_dir)
+{
+	int i;
+	long offset;
+	unsigned short rec_len;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de, * de1;
+
+	*res_dir = NULL;
+	if (!dir)
+		return NULL;
+#ifdef NO_TRUNCATE
+	if (namelen > EXT_NAME_LEN)
+		return NULL;
+#else
+	if (namelen > EXT_NAME_LEN)
+		namelen = EXT_NAME_LEN;
+#endif
+	if (!namelen)
+		return NULL;
+	bh = ext_bread(dir,0,0);
+	if (!bh)
+		return NULL;
+	rec_len = ((8 + namelen + EXT_DIR_PAD - 1) / EXT_DIR_PAD) * EXT_DIR_PAD;
+	offset = 0;
+	de = (struct ext_dir_entry *) bh->b_data;
+	while (1) {
+		if ((char *)de >= BLOCK_SIZE+bh->b_data && offset < dir->i_size) {
+#ifdef EXTFS_DEBUG
+printk ("ext_add_entry: skipping to next block\n");
+#endif
+			brelse(bh);
+			bh = NULL;
+			bh = ext_bread(dir,offset>>BLOCK_SIZE_BITS,0);
+			if (!bh)
+				return NULL;
+			de = (struct ext_dir_entry *) bh->b_data;
+		}
+		if (offset >= dir->i_size) {
+			/* Check that the directory entry fits in the block */
+			if (offset % BLOCK_SIZE == 0  ||
+			    (BLOCK_SIZE - (offset % BLOCK_SIZE)) < rec_len) {
+				if ((offset % BLOCK_SIZE) != 0) {
+					/* If the entry does not fit in the
+					   block, the remainder of the block
+					   becomes an unused entry */
+					de->inode = 0;
+					de->rec_len = BLOCK_SIZE
+						- (offset & (BLOCK_SIZE - 1));
+					de->name_len = 0;
+					offset += de->rec_len;
+					dir->i_size += de->rec_len;
+					dir->i_dirt = 1;
+#if 0
+					dir->i_ctime = CURRENT_TIME;
+#endif
+					mark_buffer_dirty(bh, 1);
+				}
+				brelse (bh);
+				bh = NULL;
+#ifdef EXTFS_DEBUG
+printk ("ext_add_entry : creating next block\n");
+#endif
+				bh = ext_bread(dir,offset>>BLOCK_SIZE_BITS,1);
+				if (!bh)
+					return NULL; /* Other thing to do ??? */
+				de = (struct ext_dir_entry *) bh->b_data;
+			}
+			/* Allocate the entry */
+			de->inode=0;
+			de->rec_len = rec_len;
+			dir->i_size += de->rec_len;
+			dir->i_dirt = 1;
+#if 0
+			dir->i_ctime = CURRENT_TIME;
+#endif
+		}
+		if (de->rec_len < 8 || de->rec_len % 4 != 0 ||
+		    de->rec_len < de->name_len + 8 ||
+		    (((char *) de) + de->rec_len-1 >= BLOCK_SIZE+bh->b_data)) {
+			printk ("ext_addr_entry: bad dir entry\n");
+			printk ("dev=%d, dir=%ld, offset=%ld, rec_len=%d, name_len=%d\n",
+				dir->i_dev, dir->i_ino, offset, de->rec_len, de->name_len);
+			brelse (bh);
+			return NULL;
+		}
+		if (!de->inode && de->rec_len >= rec_len) {
+			if (de->rec_len > rec_len
+			    && de->rec_len - rec_len >= EXT_DIR_MIN_SIZE) {
+				/* The found entry is too big : it is split
+				   into 2 ones :
+				   - the 1st one will be used to hold the name,
+				   - the 2nd one is unused */
+				de1 = (struct ext_dir_entry *) ((char *) de + rec_len);
+				de1->inode = 0;
+				de1->rec_len = de->rec_len - rec_len;
+				de1->name_len = 0;
+				de->rec_len = rec_len;
+			}
+			dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+			de->name_len = namelen;
+			for (i=0; i < namelen ; i++)
+				de->name[i] = name[i];
+			mark_buffer_dirty(bh, 1);
+			*res_dir = de;
+			return bh;
+		}
+		offset += de->rec_len;
+		de = (struct ext_dir_entry *) ((char *) de + de->rec_len);
+	}
+	brelse(bh);
+	return NULL;
+}
+
+int ext_create(struct inode * dir,const char * name, int len, int mode,
+	struct inode ** result)
+{
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de;
+
+	*result = NULL;
+	if (!dir)
+		return -ENOENT;
+	inode = ext_new_inode(dir);
+	if (!inode) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_op = &ext_file_inode_operations;
+	inode->i_mode = mode;
+	inode->i_dirt = 1;
+	bh = ext_add_entry(dir,name,len,&de);
+	if (!bh) {
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		iput(dir);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_ino;
+	mark_buffer_dirty(bh, 1);
+	brelse(bh);
+	iput(dir);
+	*result = inode;
+	return 0;
+}
+
+int ext_mknod(struct inode * dir, const char * name, int len, int mode, int rdev)
+{
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de;
+
+	if (!dir)
+		return -ENOENT;
+	bh = ext_find_entry(dir,name,len,&de,NULL,NULL);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		return -EEXIST;
+	}
+	inode = ext_new_inode(dir);
+	if (!inode) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_uid = current->fsuid;
+	inode->i_mode = mode;
+	inode->i_op = NULL;
+	if (S_ISREG(inode->i_mode))
+		inode->i_op = &ext_file_inode_operations;
+	else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &ext_dir_inode_operations;
+		if (dir->i_mode & S_ISGID)
+			inode->i_mode |= S_ISGID;
+	}
+	else if (S_ISLNK(inode->i_mode))
+		inode->i_op = &ext_symlink_inode_operations;
+	else if (S_ISCHR(inode->i_mode))
+		inode->i_op = &chrdev_inode_operations;
+	else if (S_ISBLK(inode->i_mode))
+		inode->i_op = &blkdev_inode_operations;
+	else if (S_ISFIFO(inode->i_mode))
+		init_fifo(inode);
+	if (S_ISBLK(mode) || S_ISCHR(mode))
+		inode->i_rdev = rdev;
+#if 0
+	inode->i_mtime = inode->i_atime = CURRENT_TIME;
+#endif
+	inode->i_dirt = 1;
+	bh = ext_add_entry(dir,name,len,&de);
+	if (!bh) {
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		iput(dir);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_ino;
+	mark_buffer_dirty(bh, 1);
+	brelse(bh);
+	iput(dir);
+	iput(inode);
+	return 0;
+}
+
+int ext_mkdir(struct inode * dir, const char * name, int len, int mode)
+{
+	struct inode * inode;
+	struct buffer_head * bh, *dir_block;
+	struct ext_dir_entry * de;
+	
+	bh = ext_find_entry(dir,name,len,&de,NULL,NULL);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		return -EEXIST;
+	}
+	inode = ext_new_inode(dir);
+	if (!inode) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_op = &ext_dir_inode_operations;
+	inode->i_size = 2 * 16; /* Each entry is coded on 16 bytes for "." and ".."
+					- 4 bytes for the inode number,
+					- 2 bytes for the record length
+					- 2 bytes for the name length
+					- 8 bytes for the name */
+#if 0
+	inode->i_mtime = inode->i_atime = CURRENT_TIME;
+#endif
+	dir_block = ext_bread(inode,0,1);
+	if (!dir_block) {
+		iput(dir);
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		return -ENOSPC;
+	}
+	de = (struct ext_dir_entry *) dir_block->b_data;
+	de->inode=inode->i_ino;
+	de->rec_len=16;
+	de->name_len=1;
+	strcpy(de->name,".");
+	de = (struct ext_dir_entry *) ((char *) de + de->rec_len);
+	de->inode = dir->i_ino;
+	de->rec_len=16;
+	de->name_len=2;
+	strcpy(de->name,"..");
+	inode->i_nlink = 2;
+	mark_buffer_dirty(dir_block, 1);
+	brelse(dir_block);
+	inode->i_mode = S_IFDIR | (mode & 0777 & ~current->fs->umask);
+	if (dir->i_mode & S_ISGID)
+		inode->i_mode |= S_ISGID;
+	inode->i_dirt = 1;
+	bh = ext_add_entry(dir,name,len,&de);
+	if (!bh) {
+		iput(dir);
+		inode->i_nlink=0;
+		iput(inode);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_ino;
+	mark_buffer_dirty(bh, 1);
+	dir->i_nlink++;
+	dir->i_dirt = 1;
+	iput(dir);
+	iput(inode);
+	brelse(bh);
+	return 0;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+static int empty_dir(struct inode * inode)
+{
+	unsigned long offset;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de, * de1;
+
+	if (inode->i_size < 2 * 12 || !(bh = ext_bread(inode,0,0))) {
+	    	printk("warning - bad directory on dev %04x\n",inode->i_dev);
+		return 1;
+	}
+	de = (struct ext_dir_entry *) bh->b_data;
+	de1 = (struct ext_dir_entry *) ((char *) de + de->rec_len);
+	if (de->inode != inode->i_ino || !de1->inode || 
+	    strcmp(".",de->name) || strcmp("..",de1->name)) {
+	    	printk("warning - bad directory on dev %04x\n",inode->i_dev);
+		return 1;
+	}
+	offset = de->rec_len + de1->rec_len;
+	de = (struct ext_dir_entry *) ((char *) de1 + de1->rec_len);
+	while (offset < inode->i_size ) {
+		if ((void *) de >= (void *) (bh->b_data+BLOCK_SIZE)) {
+			brelse(bh);
+			bh = ext_bread(inode, offset >> BLOCK_SIZE_BITS,1);
+			if (!bh) {
+				offset += BLOCK_SIZE;
+				continue;
+			}
+			de = (struct ext_dir_entry *) bh->b_data;
+		}
+		if (de->rec_len < 8 || de->rec_len %4 != 0 ||
+		    de->rec_len < de->name_len + 8) {
+			printk ("empty_dir: bad dir entry\n");
+			printk ("dev=%d, dir=%ld, offset=%ld, rec_len=%d, name_len=%d\n",
+				inode->i_dev, inode->i_ino, offset, de->rec_len, de->name_len);
+			brelse (bh);
+			return 1;
+		}
+		if (de->inode) {
+			brelse(bh);
+			return 0;
+		}
+		offset += de->rec_len;
+		de = (struct ext_dir_entry *) ((char *) de + de->rec_len);
+	}
+	brelse(bh);
+	return 1;
+}
+
+static inline void ext_merge_entries (struct ext_dir_entry * de,
+	struct ext_dir_entry * pde, struct ext_dir_entry * nde)
+{
+	if (nde && !nde->inode)
+		de->rec_len += nde->rec_len;
+	if (pde && !pde->inode)
+		pde->rec_len += de->rec_len;
+}
+
+int ext_rmdir(struct inode * dir, const char * name, int len)
+{
+	int retval;
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de, * pde, * nde;
+
+	inode = NULL;
+	bh = ext_find_entry(dir,name,len,&de,&pde,&nde);
+	retval = -ENOENT;
+	if (!bh)
+		goto end_rmdir;
+	retval = -EPERM;
+	if (!(inode = iget(dir->i_sb, de->inode)))
+		goto end_rmdir;
+        if ((dir->i_mode & S_ISVTX) && !fsuser() &&
+            current->fsuid != inode->i_uid &&
+            current->fsuid != dir->i_uid)
+		goto end_rmdir;
+	if (inode->i_dev != dir->i_dev)
+		goto end_rmdir;
+	if (inode == dir)	/* we may not delete ".", but "../dir" is ok */
+		goto end_rmdir;
+	if (!S_ISDIR(inode->i_mode)) {
+		retval = -ENOTDIR;
+		goto end_rmdir;
+	}
+	if (!empty_dir(inode)) {
+		retval = -ENOTEMPTY;
+		goto end_rmdir;
+	}
+	if (inode->i_count > 1) {
+		retval = -EBUSY;
+		goto end_rmdir;
+	}
+	if (inode->i_nlink != 2)
+		printk("empty directory has nlink!=2 (%d)\n",inode->i_nlink);
+	de->inode = 0;
+	de->name_len = 0;
+	ext_merge_entries (de, pde, nde);
+	mark_buffer_dirty(bh, 1);
+	inode->i_nlink=0;
+	inode->i_dirt=1;
+	dir->i_nlink--;
+	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->i_dirt=1;
+	retval = 0;
+end_rmdir:
+	iput(dir);
+	iput(inode);
+	brelse(bh);
+	return retval;
+}
+
+int ext_unlink(struct inode * dir, const char * name, int len)
+{
+	int retval;
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext_dir_entry * de, * pde, * nde;
+
+	retval = -ENOENT;
+	inode = NULL;
+	bh = ext_find_entry(dir,name,len,&de,&pde,&nde);
+	if (!bh)
+		goto end_unlink;
+	if (!(inode = iget(dir->i_sb, de->inode)))
+		goto end_unlink;
+	retval = -EPERM;
+	if ((dir->i_mode & S_ISVTX) && !fsuser() &&
+	    current->fsuid != inode->i_uid &&
+	    current->fsuid != dir->i_uid)
+		goto end_unlink;
+	if (S_ISDIR(inode->i_mode))
+		goto end_unlink;
+	if (!inode->i_nlink) {
+		printk("Deleting nonexistent file (%04x:%ld), %d\n",
+			inode->i_dev,inode->i_ino,inode->i_nlink);
+		inode->i_nlink=1;
+	}
+	de->inode = 0;
+	de->name_len = 0;
+	ext_merge_entries (de, pde, nde);
+	mark_buffer_dirty(bh, 1);
+	inode->i_nlink--;
+	inode->i_dirt = 1;
+	inode->i_ctime = CURRENT_TIME;
+	dir->i_ctime = dir->i_mtime = inode->i_ctime;
+	dir->i_dirt = 1;
+	retval = 0;
+end_unlink:
+	brelse(bh);
+	iput(inode);
+	iput(dir);
+	return retval;
+}
+
+int ext_symlink(struct inode * dir, const char * name, int len, const char * symname)
+{
+	struct ext_dir_entry * de;
+	struct inode * inode = NULL;
+	struct buffer_head * bh = NULL, * name_block = NULL;
+	int i;
+	char c;
+
+	if (!(inode = ext_new_inode(dir))) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_mode = S_IFLNK | 0777;
+	inode->i_op = &ext_symlink_inode_operations;
+	name_block = ext_bread(inode,0,1);
+	if (!name_block) {
+		iput(dir);
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		return -ENOSPC;
+	}
+	i = 0;
+	while (i < 1023 && (c = *(symname++)))
+		name_block->b_data[i++] = c;
+	name_block->b_data[i] = 0;
+	mark_buffer_dirty(name_block, 1);
+	brelse(name_block);
+	inode->i_size = i;
+	inode->i_dirt = 1;
+	bh = ext_find_entry(dir,name,len,&de,NULL,NULL);
+	if (bh) {
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		brelse(bh);
+		iput(dir);
+		return -EEXIST;
+	}
+	bh = ext_add_entry(dir,name,len,&de);
+	if (!bh) {
+		inode->i_nlink--;
+		inode->i_dirt = 1;
+		iput(inode);
+		iput(dir);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_ino;
+	mark_buffer_dirty(bh, 1);
+	brelse(bh);
+	iput(dir);
+	iput(inode);
+	return 0;
+}
+
+int ext_link(struct inode * oldinode, struct inode * dir, const char * name, int len)
+{
+	struct ext_dir_entry * de;
+	struct buffer_head * bh;
+
+	if (S_ISDIR(oldinode->i_mode)) {
+		iput(oldinode);
+		iput(dir);
+		return -EPERM;
+	}
+	if (oldinode->i_nlink > 32000) {
+		iput(oldinode);
+		iput(dir);
+		return -EMLINK;
+	}
+	bh = ext_find_entry(dir,name,len,&de,NULL,NULL);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		iput(oldinode);
+		return -EEXIST;
+	}
+	bh = ext_add_entry(dir,name,len,&de);
+	if (!bh) {
+		iput(dir);
+		iput(oldinode);
+		return -ENOSPC;
+	}
+	de->inode = oldinode->i_ino;
+	mark_buffer_dirty(bh, 1);
+	brelse(bh);
+	iput(dir);
+	oldinode->i_nlink++;
+	oldinode->i_ctime = CURRENT_TIME;
+	oldinode->i_dirt = 1;
+	iput(oldinode);
+	return 0;
+}
+
+static int subdir(struct inode * new_inode, struct inode * old_inode)
+{
+	int ino;
+	int result;
+
+	new_inode->i_count++;
+	result = 0;
+	for (;;) {
+		if (new_inode == old_inode) {
+			result = 1;
+			break;
+		}
+		if (new_inode->i_dev != old_inode->i_dev)
+			break;
+		ino = new_inode->i_ino;
+		if (ext_lookup(new_inode,"..",2,&new_inode))
+			break;
+		if (new_inode->i_ino == ino)
+			break;
+	}
+	iput(new_inode);
+	return result;
+}
+
+#define PARENT_INO(buffer) \
+((struct ext_dir_entry *) ((char *) buffer + \
+((struct ext_dir_entry *) buffer)->rec_len))->inode
+
+#define PARENT_NAME(buffer) \
+((struct ext_dir_entry *) ((char *) buffer + \
+((struct ext_dir_entry *) buffer)->rec_len))->name
+
+/*
+ * rename uses retrying to avoid race-conditions: at least they should be minimal.
+ * it tries to allocate all the blocks, then sanity-checks, and if the sanity-
+ * checks fail, it tries to restart itself again. Very practical - no changes
+ * are done until we know everything works ok.. and then all the changes can be
+ * done in one fell swoop when we have claimed all the buffers needed.
+ *
+ * Anybody can rename anything with this: the permission checks are left to the
+ * higher-level routines.
+ */
+static int do_ext_rename(struct inode * old_dir, const char * old_name, int old_len,
+	struct inode * new_dir, const char * new_name, int new_len)
+{
+	struct inode * old_inode, * new_inode;
+	struct buffer_head * old_bh, * new_bh, * dir_bh;
+	struct ext_dir_entry * old_de, * new_de, * pde, * nde;
+	int retval;
+
+	goto start_up;
+try_again:
+	brelse(old_bh);
+	brelse(new_bh);
+	brelse(dir_bh);
+	iput(old_inode);
+	iput(new_inode);
+	current->counter = 0;
+	schedule();
+start_up:
+	old_inode = new_inode = NULL;
+	old_bh = new_bh = dir_bh = NULL;
+	old_bh = ext_find_entry(old_dir,old_name,old_len,&old_de,&pde,&nde);
+	retval = -ENOENT;
+	if (!old_bh)
+		goto end_rename;
+	old_inode = __iget(old_dir->i_sb, old_de->inode,0); /* don't cross mnt-points */
+	if (!old_inode)
+		goto end_rename;
+	retval = -EPERM;
+	if ((old_dir->i_mode & S_ISVTX) && 
+	    current->fsuid != old_inode->i_uid &&
+	    current->fsuid != old_dir->i_uid && !fsuser())
+		goto end_rename;
+	new_bh = ext_find_entry(new_dir,new_name,new_len,&new_de,NULL,NULL);
+	if (new_bh) {
+		new_inode = __iget(new_dir->i_sb, new_de->inode,0); /* don't cross mnt-points */
+		if (!new_inode) {
+			brelse(new_bh);
+			new_bh = NULL;
+		}
+	}
+	if (new_inode == old_inode) {
+		retval = 0;
+		goto end_rename;
+	}
+	if (new_inode && S_ISDIR(new_inode->i_mode)) {
+		retval = -EEXIST;
+		goto end_rename;
+	}
+	retval = -EPERM;
+	if (new_inode && (new_dir->i_mode & S_ISVTX) && 
+	    current->fsuid != new_inode->i_uid &&
+	    current->fsuid != new_dir->i_uid && !fsuser())
+		goto end_rename;
+	if (S_ISDIR(old_inode->i_mode)) {
+		retval = -EEXIST;
+		if (new_bh)
+			goto end_rename;
+		retval = -EACCES;
+		if (!permission(old_inode, MAY_WRITE))
+			goto end_rename;
+		retval = -EINVAL;
+		if (subdir(new_dir, old_inode))
+			goto end_rename;
+		retval = -EIO;
+		dir_bh = ext_bread(old_inode,0,0);
+		if (!dir_bh)
+			goto end_rename;
+		if (PARENT_INO(dir_bh->b_data) != old_dir->i_ino)
+			goto end_rename;
+	}
+	if (!new_bh)
+		new_bh = ext_add_entry(new_dir,new_name,new_len,&new_de);
+	retval = -ENOSPC;
+	if (!new_bh)
+		goto end_rename;
+/* sanity checking before doing the rename - avoid races */
+	if (new_inode && (new_de->inode != new_inode->i_ino))
+		goto try_again;
+	if (new_de->inode && !new_inode)
+		goto try_again;
+	if (old_de->inode != old_inode->i_ino)
+		goto try_again;
+/* ok, that's it */
+	old_de->inode = 0;
+	old_de->name_len = 0;
+	new_de->inode = old_inode->i_ino;
+	ext_merge_entries (old_de, pde, nde);
+	if (new_inode) {
+		new_inode->i_nlink--;
+		new_inode->i_dirt = 1;
+	}
+	mark_buffer_dirty(old_bh, 1);
+	mark_buffer_dirty(new_bh, 1);
+	if (dir_bh) {
+		PARENT_INO(dir_bh->b_data) = new_dir->i_ino;
+		mark_buffer_dirty(dir_bh, 1);
+		old_dir->i_nlink--;
+		new_dir->i_nlink++;
+		old_dir->i_dirt = 1;
+		new_dir->i_dirt = 1;
+	}
+	retval = 0;
+end_rename:
+	brelse(dir_bh);
+	brelse(old_bh);
+	brelse(new_bh);
+	iput(old_inode);
+	iput(new_inode);
+	iput(old_dir);
+	iput(new_dir);
+	return retval;
+}
+
+/*
+ * Ok, rename also locks out other renames, as they can change the parent of
+ * a directory, and we don't want any races. Other races are checked for by
+ * "do_rename()", which restarts if there are inconsistencies.
+ *
+ * Note that there is no race between different filesystems: it's only within
+ * the same device that races occur: many renames can happen at once, as long
+ * as they are on different partitions.
+ */
+int ext_rename(struct inode * old_dir, const char * old_name, int old_len,
+	struct inode * new_dir, const char * new_name, int new_len)
+{
+	static struct wait_queue * wait = NULL;
+	static int lock = 0;
+	int result;
+
+	while (lock)
+		sleep_on(&wait);
+	lock = 1;
+	result = do_ext_rename(old_dir, old_name, old_len,
+		new_dir, new_name, new_len);
+	lock = 0;
+	wake_up(&wait);
+	return result;
+}