patch-2.4.6 linux/fs/ext2/namei.c

• Lines: 1020
• Date: Mon Jun 11 19:15:27 2001
• Orig file: v2.4.5/linux/fs/ext2/namei.c
• Orig date: Thu Feb 15 12:32:21 2001

diff -u --recursive --new-file v2.4.5/linux/fs/ext2/namei.c linux/fs/ext2/namei.c
@@ -1,5 +1,18 @@
 /*
- *  linux/fs/ext2/namei.c
+ * linux/fs/ext2/namei.c
+ *
+ * Rewrite to pagecache. Almost all code had been changed, so blame me
+ * if the things go wrong. Please, send bug reports to viro@math.psu.edu
+ *
+ * Stuff here is basically a glue between the VFS and generic UNIXish
+ * filesystem that keeps everything in pagecache. All knowledge of the
+ * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
+ * and it's easier to debug that way. In principle we might want to
+ * generalize that a bit and turn it into a library. Or not.
+ *
+ * The only non-static object here is ext2_dir_inode_operations.
+ *
+ * TODO: get rid of kmap() use, add readahead.
  *
  * Copyright (C) 1992, 1993, 1994, 1995
  * Remy Card (card@masi.ibp.fr)
@@ -14,344 +27,63 @@
  *
  *  Big-endian to little-endian byte-swapping/bitmaps by
  *        David S. Miller (davem@caip.rutgers.edu), 1995
- *  Directory entry file type support and forward compatibility hooks
- *  	for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  */
 
 #include <linux/fs.h>
 #include <linux/ext2_fs.h>
-#include <linux/locks.h>
-#include <linux/quotaops.h>
-
-
+#include <linux/pagemap.h>
 
 /*
- * define how far ahead to read directories while searching them.
+ * Couple of helper functions - make the code slightly cleaner.
  */
-#define NAMEI_RA_CHUNKS  2
-#define NAMEI_RA_BLOCKS  4
-#define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
-#define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
 
-/*
- * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
- *
- * `len <= EXT2_NAME_LEN' is guaranteed by caller.
- * `de != NULL' is guaranteed by caller.
- */
-static inline int ext2_match (int len, const char * const name,
-		       struct ext2_dir_entry_2 * de)
+static inline void ext2_inc_count(struct inode *inode)
 {
-	if (len != de->name_len)
-		return 0;
-	if (!de->inode)
-		return 0;
-	return !memcmp(name, de->name, len);
+	inode->i_nlink++;
+	mark_inode_dirty(inode);
 }
 
-/*
- *	ext2_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.
- */
-static struct buffer_head * ext2_find_entry (struct inode * dir,
-					     const char * const name, int namelen,
-					     struct ext2_dir_entry_2 ** res_dir)
-{
-	struct super_block * sb;
-	struct buffer_head * bh_use[NAMEI_RA_SIZE];
-	struct buffer_head * bh_read[NAMEI_RA_SIZE];
-	unsigned long offset;
-	int block, toread, i, err;
-
-	*res_dir = NULL;
-	sb = dir->i_sb;
-
-	if (namelen > EXT2_NAME_LEN)
-		return NULL;
-
-	memset (bh_use, 0, sizeof (bh_use));
-	toread = 0;
-	for (block = 0; block < NAMEI_RA_SIZE; ++block) {
-		struct buffer_head * bh;
-
-		if ((block << EXT2_BLOCK_SIZE_BITS (sb)) >= dir->i_size)
-			break;
-		bh = ext2_getblk (dir, block, 0, &err);
-		bh_use[block] = bh;
-		if (bh && !buffer_uptodate(bh))
-			bh_read[toread++] = bh;
-	}
-
-	for (block = 0, offset = 0; offset < dir->i_size; block++) {
-		struct buffer_head * bh;
-		struct ext2_dir_entry_2 * de;
-		char * dlimit;
-
-		if ((block % NAMEI_RA_BLOCKS) == 0 && toread) {
-			ll_rw_block (READ, toread, bh_read);
-			toread = 0;
-		}
-		bh = bh_use[block % NAMEI_RA_SIZE];
-		if (!bh) {
-#if 0
-			ext2_error (sb, "ext2_find_entry",
-				    "directory #%lu contains a hole at offset %lu",
-				    dir->i_ino, offset);
-#endif
-			offset += sb->s_blocksize;
-			continue;
-		}
-		wait_on_buffer (bh);
-		if (!buffer_uptodate(bh)) {
-			/*
-			 * read error: all bets are off
-			 */
-			break;
-		}
-
-		de = (struct ext2_dir_entry_2 *) bh->b_data;
-		dlimit = bh->b_data + sb->s_blocksize;
-		while ((char *) de < dlimit) {
-			/* this code is executed quadratically often */
-			/* do minimal checking `by hand' */
-			int de_len;
-
-			if ((char *) de + namelen <= dlimit &&
-			    ext2_match (namelen, name, de)) {
-				/* found a match -
-				   just to be sure, do a full check */
-				if (!ext2_check_dir_entry("ext2_find_entry",
-							  dir, de, bh, offset))
-					goto failure;
-				for (i = 0; i < NAMEI_RA_SIZE; ++i) {
-					if (bh_use[i] != bh)
-						brelse (bh_use[i]);
-				}
-				*res_dir = de;
-				return bh;
-			}
-			/* prevent looping on a bad block */
-			de_len = le16_to_cpu(de->rec_len);
-			if (de_len <= 0)
-				goto failure;
-			offset += de_len;
-			de = (struct ext2_dir_entry_2 *)
-				((char *) de + de_len);
-		}
+static inline void ext2_dec_count(struct inode *inode)
+{
+	inode->i_nlink--;
+	mark_inode_dirty(inode);
+}
 
-		brelse (bh);
-		if (((block + NAMEI_RA_SIZE) << EXT2_BLOCK_SIZE_BITS (sb)) >=
-		    dir->i_size)
-			bh = NULL;
-		else
-			bh = ext2_getblk (dir, block + NAMEI_RA_SIZE, 0, &err);
-		bh_use[block % NAMEI_RA_SIZE] = bh;
-		if (bh && !buffer_uptodate(bh))
-			bh_read[toread++] = bh;
+static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
+{
+	int err = ext2_add_link(dentry, inode);
+	if (!err) {
+		d_instantiate(dentry, inode);
+		return 0;
 	}
-
-failure:
-	for (i = 0; i < NAMEI_RA_SIZE; ++i)
-		brelse (bh_use[i]);
-	return NULL;
+	ext2_dec_count(inode);
+	iput(inode);
+	return err;
 }
 
+/*
+ * Methods themselves.
+ */
+
 static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry)
 {
 	struct inode * inode;
-	struct ext2_dir_entry_2 * de;
-	struct buffer_head * bh;
-
+	ino_t ino;
+	
 	if (dentry->d_name.len > EXT2_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	bh = ext2_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de);
+	ino = ext2_inode_by_name(dir, dentry);
 	inode = NULL;
-	if (bh) {
-		unsigned long ino = le32_to_cpu(de->inode);
-		brelse (bh);
+	if (ino) {
 		inode = iget(dir->i_sb, ino);
-
-		if (!inode)
+		if (!inode) 
 			return ERR_PTR(-EACCES);
 	}
 	d_add(dentry, inode);
 	return NULL;
 }
 
-#define S_SHIFT 12
-static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = {
-	[S_IFREG >> S_SHIFT]	EXT2_FT_REG_FILE,
-	[S_IFDIR >> S_SHIFT]	EXT2_FT_DIR,
-	[S_IFCHR >> S_SHIFT]	EXT2_FT_CHRDEV,
-	[S_IFBLK >> S_SHIFT]	EXT2_FT_BLKDEV,
-	[S_IFIFO >> S_SHIFT]	EXT2_FT_FIFO,
-	[S_IFSOCK >> S_SHIFT]	EXT2_FT_SOCK,
-	[S_IFLNK >> S_SHIFT]	EXT2_FT_SYMLINK,
-};
-
-static inline void ext2_set_de_type(struct super_block *sb,
-				struct ext2_dir_entry_2 *de,
-				umode_t mode) {
-	if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
-		de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
-}
-
-/*
- *	ext2_add_entry()
- *
- * adds a file entry to the specified directory.
- */
-int ext2_add_entry (struct inode * dir, const char * name, int namelen,
-		    struct inode *inode)
-{
-	unsigned long offset;
-	unsigned short rec_len;
-	struct buffer_head * bh;
-	struct ext2_dir_entry_2 * de, * de1;
-	struct super_block * sb;
-	int	retval;
-
-	sb = dir->i_sb;
-
-	if (!namelen)
-		return -EINVAL;
-	bh = ext2_bread (dir, 0, 0, &retval);
-	if (!bh)
-		return retval;
-	rec_len = EXT2_DIR_REC_LEN(namelen);
-	offset = 0;
-	de = (struct ext2_dir_entry_2 *) bh->b_data;
-	while (1) {
-		if ((char *)de >= sb->s_blocksize + bh->b_data) {
-			brelse (bh);
-			bh = NULL;
-			bh = ext2_bread (dir, offset >> EXT2_BLOCK_SIZE_BITS(sb), 1, &retval);
-			if (!bh)
-				return retval;
-			if (dir->i_size <= offset) {
-				if (dir->i_size == 0) {
-					brelse(bh);
-					return -ENOENT;
-				}
-
-				ext2_debug ("creating next block\n");
-
-				de = (struct ext2_dir_entry_2 *) bh->b_data;
-				de->inode = 0;
-				de->rec_len = le16_to_cpu(sb->s_blocksize);
-				dir->i_size = offset + sb->s_blocksize;
-				dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-				mark_inode_dirty(dir);
-			} else {
-
-				ext2_debug ("skipping to next block\n");
-
-				de = (struct ext2_dir_entry_2 *) bh->b_data;
-			}
-		}
-		if (!ext2_check_dir_entry ("ext2_add_entry", dir, de, bh,
-					   offset)) {
-			brelse (bh);
-			return -ENOENT;
-		}
-		if (ext2_match (namelen, name, de)) {
-				brelse (bh);
-				return -EEXIST;
-		}
-		if ((le32_to_cpu(de->inode) == 0 && le16_to_cpu(de->rec_len) >= rec_len) ||
-		    (le16_to_cpu(de->rec_len) >= EXT2_DIR_REC_LEN(de->name_len) + rec_len)) {
-			offset += le16_to_cpu(de->rec_len);
-			if (le32_to_cpu(de->inode)) {
-				de1 = (struct ext2_dir_entry_2 *) ((char *) de +
-					EXT2_DIR_REC_LEN(de->name_len));
-				de1->rec_len = cpu_to_le16(le16_to_cpu(de->rec_len) -
-					EXT2_DIR_REC_LEN(de->name_len));
-				de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
-				de = de1;
-			}
-			de->file_type = EXT2_FT_UNKNOWN;
-			if (inode) {
-				de->inode = cpu_to_le32(inode->i_ino);
-				ext2_set_de_type(dir->i_sb, de, inode->i_mode);
-			} else
-				de->inode = 0;
-			de->name_len = namelen;
-			memcpy (de->name, name, namelen);
-			/*
-			 * XXX shouldn't update any times until successful
-			 * completion of syscall, but too many callers depend
-			 * on this.
-			 *
-			 * XXX similarly, too many callers depend on
-			 * ext2_new_inode() setting the times, but error
-			 * recovery deletes the inode, so the worst that can
-			 * happen is that the times are slightly out of date
-			 * and/or different from the directory change time.
-			 */
-			dir->i_mtime = dir->i_ctime = CURRENT_TIME;
-			dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-			mark_inode_dirty(dir);
-			dir->i_version = ++event;
-			mark_buffer_dirty_inode(bh, dir);
-			if (IS_SYNC(dir)) {
-				ll_rw_block (WRITE, 1, &bh);
-				wait_on_buffer (bh);
-			}
-			brelse(bh);
-			return 0;
-		}
-		offset += le16_to_cpu(de->rec_len);
-		de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
-	}
-	brelse (bh);
-	return -ENOSPC;
-}
-
-/*
- * ext2_delete_entry deletes a directory entry by merging it with the
- * previous entry
- */
-static int ext2_delete_entry (struct inode * dir,
-			      struct ext2_dir_entry_2 * de_del,
-			      struct buffer_head * bh)
-{
-	struct ext2_dir_entry_2 * de, * pde;
-	int i;
-
-	i = 0;
-	pde = NULL;
-	de = (struct ext2_dir_entry_2 *) bh->b_data;
-	while (i < bh->b_size) {
-		if (!ext2_check_dir_entry ("ext2_delete_entry", NULL, 
-					   de, bh, i))
-			return -EIO;
-		if (de == de_del)  {
-			if (pde)
-				pde->rec_len =
-					cpu_to_le16(le16_to_cpu(pde->rec_len) +
-						    le16_to_cpu(de->rec_len));
-			else
-				de->inode = 0;
-			dir->i_version = ++event;
-			mark_buffer_dirty_inode(bh, dir);
-			if (IS_SYNC(dir)) {
-				ll_rw_block (WRITE, 1, &bh);
-				wait_on_buffer (bh);
-			}
-			return 0;
-		}
-		i += le16_to_cpu(de->rec_len);
-		pde = de;
-		de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
-	}
-	return -ENOENT;
-}
-
 /*
  * By the time this is called, we already have created
  * the directory cache entry for the new file, but it
@@ -364,454 +96,245 @@
 {
 	struct inode * inode = ext2_new_inode (dir, mode);
 	int err = PTR_ERR(inode);
-	if (IS_ERR(inode))
-		return err;
-
-	inode->i_op = &ext2_file_inode_operations;
-	inode->i_fop = &ext2_file_operations;
-	inode->i_mapping->a_ops = &ext2_aops;
-	inode->i_mode = mode;
-	mark_inode_dirty(inode);
-	err = ext2_add_entry (dir, dentry->d_name.name, dentry->d_name.len, 
-			     inode);
-	if (err) {
-		inode->i_nlink--;
+	if (!IS_ERR(inode)) {
+		inode->i_op = &ext2_file_inode_operations;
+		inode->i_fop = &ext2_file_operations;
+		inode->i_mapping->a_ops = &ext2_aops;
 		mark_inode_dirty(inode);
-		iput (inode);
-		return err;
+		err = ext2_add_nondir(dentry, inode);
 	}
-	d_instantiate(dentry, inode);
-	return 0;
+	return err;
 }
 
 static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, int rdev)
 {
 	struct inode * inode = ext2_new_inode (dir, mode);
 	int err = PTR_ERR(inode);
-
-	if (IS_ERR(inode))
-		return err;
-
-	inode->i_uid = current->fsuid;
-	init_special_inode(inode, mode, rdev);
-	err = ext2_add_entry (dir, dentry->d_name.name, dentry->d_name.len, 
-			     inode);
-	if (err)
-		goto out_no_entry;
-	mark_inode_dirty(inode);
-	d_instantiate(dentry, inode);
-	return 0;
-
-out_no_entry:
-	inode->i_nlink--;
-	mark_inode_dirty(inode);
-	iput(inode);
+	if (!IS_ERR(inode)) {
+		init_special_inode(inode, mode, rdev);
+		mark_inode_dirty(inode);
+		err = ext2_add_nondir(dentry, inode);
+	}
 	return err;
 }
 
-static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+static int ext2_symlink (struct inode * dir, struct dentry * dentry,
+	const char * symname)
 {
+	struct super_block * sb = dir->i_sb;
+	int err = -ENAMETOOLONG;
+	unsigned l = strlen(symname)+1;
 	struct inode * inode;
-	struct buffer_head * dir_block;
-	struct ext2_dir_entry_2 * de;
-	int err;
 
-	if (dir->i_nlink >= EXT2_LINK_MAX)
-		return -EMLINK;
+	if (l > sb->s_blocksize)
+		goto out;
 
-	inode = ext2_new_inode (dir, S_IFDIR);
+	inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
 	err = PTR_ERR(inode);
 	if (IS_ERR(inode))
-		return err;
+		goto out;
 
-	inode->i_op = &ext2_dir_inode_operations;
-	inode->i_fop = &ext2_dir_operations;
-	inode->i_size = inode->i_sb->s_blocksize;
-	inode->i_blocks = 0;	
-	dir_block = ext2_bread (inode, 0, 1, &err);
-	if (!dir_block) {
-		inode->i_nlink--; /* is this nlink == 0? */
-		mark_inode_dirty(inode);
-		iput (inode);
-		return err;
+	if (l > sizeof (inode->u.ext2_i.i_data)) {
+		/* slow symlink */
+		inode->i_op = &page_symlink_inode_operations;
+		inode->i_mapping->a_ops = &ext2_aops;
+		err = block_symlink(inode, symname, l);
+		if (err)
+			goto out_fail;
+	} else {
+		/* fast symlink */
+		inode->i_op = &ext2_fast_symlink_inode_operations;
+		memcpy((char*)&inode->u.ext2_i.i_data,symname,l);
+		inode->i_size = l-1;
 	}
-	de = (struct ext2_dir_entry_2 *) dir_block->b_data;
-	de->inode = cpu_to_le32(inode->i_ino);
-	de->name_len = 1;
-	de->rec_len = cpu_to_le16(EXT2_DIR_REC_LEN(de->name_len));
-	strcpy (de->name, ".");
-	ext2_set_de_type(dir->i_sb, de, S_IFDIR);
-	de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
-	de->inode = cpu_to_le32(dir->i_ino);
-	de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize - EXT2_DIR_REC_LEN(1));
-	de->name_len = 2;
-	strcpy (de->name, "..");
-	ext2_set_de_type(dir->i_sb, de, S_IFDIR);
-	inode->i_nlink = 2;
-	mark_buffer_dirty_inode(dir_block, dir);
-	brelse (dir_block);
-	inode->i_mode = S_IFDIR | mode;
-	if (dir->i_mode & S_ISGID)
-		inode->i_mode |= S_ISGID;
 	mark_inode_dirty(inode);
-	err = ext2_add_entry (dir, dentry->d_name.name, dentry->d_name.len, 
-			     inode);
-	if (err)
-		goto out_no_entry;
-	dir->i_nlink++;
-	dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-	mark_inode_dirty(dir);
-	d_instantiate(dentry, inode);
-	return 0;
 
-out_no_entry:
-	inode->i_nlink = 0;
-	mark_inode_dirty(inode);
-	iput (inode);
+	err = ext2_add_nondir(dentry, inode);
+out:
 	return err;
-}
 
-/*
- * 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 ext2_dir_entry_2 * de, * de1;
-	struct super_block * sb;
-	int err;
-
-	sb = inode->i_sb;
-	if (inode->i_size < EXT2_DIR_REC_LEN(1) + EXT2_DIR_REC_LEN(2) ||
-	    !(bh = ext2_bread (inode, 0, 0, &err))) {
-	    	ext2_warning (inode->i_sb, "empty_dir",
-			      "bad directory (dir #%lu) - no data block",
-			      inode->i_ino);
-		return 1;
-	}
-	de = (struct ext2_dir_entry_2 *) bh->b_data;
-	de1 = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
-	if (le32_to_cpu(de->inode) != inode->i_ino || !le32_to_cpu(de1->inode) || 
-	    strcmp (".", de->name) || strcmp ("..", de1->name)) {
-	    	ext2_warning (inode->i_sb, "empty_dir",
-			      "bad directory (dir #%lu) - no `.' or `..'",
-			      inode->i_ino);
-		brelse (bh);
-		return 1;
-	}
-	offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
-	de = (struct ext2_dir_entry_2 *) ((char *) de1 + le16_to_cpu(de1->rec_len));
-	while (offset < inode->i_size ) {
-		if (!bh || (void *) de >= (void *) (bh->b_data + sb->s_blocksize)) {
-			brelse (bh);
-			bh = ext2_bread (inode, offset >> EXT2_BLOCK_SIZE_BITS(sb), 0, &err);
-			if (!bh) {
-#if 0
-				ext2_error (sb, "empty_dir",
-					    "directory #%lu contains a hole at offset %lu",
-					    inode->i_ino, offset);
-#endif
-				offset += sb->s_blocksize;
-				continue;
-			}
-			de = (struct ext2_dir_entry_2 *) bh->b_data;
-		}
-		if (!ext2_check_dir_entry ("empty_dir", inode, de, bh,
-					   offset)) {
-			brelse (bh);
-			return 1;
-		}
-		if (le32_to_cpu(de->inode)) {
-			brelse (bh);
-			return 0;
-		}
-		offset += le16_to_cpu(de->rec_len);
-		de = (struct ext2_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
-	}
-	brelse (bh);
-	return 1;
+out_fail:
+	ext2_dec_count(inode);
+	iput (inode);
+	goto out;
 }
 
-static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
+static int ext2_link (struct dentry * old_dentry, struct inode * dir,
+	struct dentry *dentry)
 {
-	int retval;
-	struct inode * inode;
-	struct buffer_head * bh;
-	struct ext2_dir_entry_2 * de;
+	struct inode *inode = old_dentry->d_inode;
 
-	retval = -ENOENT;
-	bh = ext2_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de);
-	if (!bh)
-		goto end_rmdir;
-
-	inode = dentry->d_inode;
-	DQUOT_INIT(inode);
-
-	retval = -EIO;
-	if (le32_to_cpu(de->inode) != inode->i_ino)
-		goto end_rmdir;
-
-	retval = -ENOTEMPTY;
-	if (!empty_dir (inode))
-		goto end_rmdir;
-
-	retval = ext2_delete_entry(dir, de, bh);
-	if (retval)
-		goto end_rmdir;
-	if (inode->i_nlink != 2)
-		ext2_warning (inode->i_sb, "ext2_rmdir",
-			      "empty directory has nlink!=2 (%d)",
-			      inode->i_nlink);
-	inode->i_version = ++event;
-	inode->i_nlink = 0;
-	inode->i_size = 0;
-	mark_inode_dirty(inode);
-	dir->i_nlink--;
-	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-	mark_inode_dirty(dir);
-
-end_rmdir:
-	brelse (bh);
-	return retval;
-}
+	if (S_ISDIR(inode->i_mode))
+		return -EPERM;
 
-static int ext2_unlink(struct inode * dir, struct dentry *dentry)
-{
-	int retval;
-	struct inode * inode;
-	struct buffer_head * bh;
-	struct ext2_dir_entry_2 * de;
+	if (inode->i_nlink >= EXT2_LINK_MAX)
+		return -EMLINK;
 
-	retval = -ENOENT;
-	bh = ext2_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &de);
-	if (!bh)
-		goto end_unlink;
-
-	inode = dentry->d_inode;
-	DQUOT_INIT(inode);
-
-	retval = -EIO;
-	if (le32_to_cpu(de->inode) != inode->i_ino)
-		goto end_unlink;
-	
-	if (!inode->i_nlink) {
-		ext2_warning (inode->i_sb, "ext2_unlink",
-			      "Deleting nonexistent file (%lu), %d",
-			      inode->i_ino, inode->i_nlink);
-		inode->i_nlink = 1;
-	}
-	retval = ext2_delete_entry(dir, de, bh);
-	if (retval)
-		goto end_unlink;
-	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-	mark_inode_dirty(dir);
-	inode->i_nlink--;
-	mark_inode_dirty(inode);
-	inode->i_ctime = dir->i_ctime;
-	retval = 0;
+	inode->i_ctime = CURRENT_TIME;
+	ext2_inc_count(inode);
+	atomic_inc(&inode->i_count);
 
-end_unlink:
-	brelse (bh);
-	return retval;
+	return ext2_add_nondir(dentry, inode);
 }
 
-static int ext2_symlink (struct inode * dir, struct dentry *dentry, const char * symname)
+static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 {
 	struct inode * inode;
-	int l, err;
+	int err = -EMLINK;
 
-	l = strlen(symname)+1;
-	if (l > dir->i_sb->s_blocksize)
-		return -ENAMETOOLONG;
+	if (dir->i_nlink >= EXT2_LINK_MAX)
+		goto out;
+
+	ext2_inc_count(dir);
 
-	inode = ext2_new_inode (dir, S_IFLNK);
+	inode = ext2_new_inode (dir, S_IFDIR | mode);
 	err = PTR_ERR(inode);
 	if (IS_ERR(inode))
-		return err;
+		goto out_dir;
 
-	inode->i_mode = S_IFLNK | S_IRWXUGO;
+	inode->i_op = &ext2_dir_inode_operations;
+	inode->i_fop = &ext2_dir_operations;
+	inode->i_mapping->a_ops = &ext2_aops;
 
-	if (l > sizeof (inode->u.ext2_i.i_data)) {
-		inode->i_op = &page_symlink_inode_operations;
-		inode->i_mapping->a_ops = &ext2_aops;
-		err = block_symlink(inode, symname, l);
-		if (err)
-			goto out_no_entry;
-	} else {
-		inode->i_op = &ext2_fast_symlink_inode_operations;
-		memcpy((char*)&inode->u.ext2_i.i_data,symname,l);
-		inode->i_size = l-1;
-	}
-	mark_inode_dirty(inode);
+	ext2_inc_count(inode);
 
-	err = ext2_add_entry (dir, dentry->d_name.name, dentry->d_name.len, 
-			     inode);
+	err = ext2_make_empty(inode, dir);
 	if (err)
-		goto out_no_entry;
-	d_instantiate(dentry, inode);
-	return 0;
+		goto out_fail;
 
-out_no_entry:
-	inode->i_nlink--;
-	mark_inode_dirty(inode);
-	iput (inode);
+	err = ext2_add_link(dentry, inode);
+	if (err)
+		goto out_fail;
+
+	d_instantiate(dentry, inode);
+out:
 	return err;
+
+out_fail:
+	ext2_dec_count(inode);
+	ext2_dec_count(inode);
+	iput(inode);
+out_dir:
+	ext2_dec_count(dir);
+	goto out;
 }
 
-static int ext2_link (struct dentry * old_dentry,
-		struct inode * dir, struct dentry *dentry)
+static int ext2_unlink(struct inode * dir, struct dentry *dentry)
 {
-	struct inode *inode = old_dentry->d_inode;
-	int err;
+	struct inode * inode = dentry->d_inode;
+	struct ext2_dir_entry_2 * de;
+	struct page * page;
+	int err = -ENOENT;
 
-	if (S_ISDIR(inode->i_mode))
-		return -EPERM;
+	de = ext2_find_entry (dir, dentry, &page);
+	if (!de)
+		goto out;
 
-	if (inode->i_nlink >= EXT2_LINK_MAX)
-		return -EMLINK;
-	
-	err = ext2_add_entry (dir, dentry->d_name.name, dentry->d_name.len, 
-			     inode);
+	err = ext2_delete_entry (de, page);
 	if (err)
-		return err;
+		goto out;
 
-	inode->i_nlink++;
-	inode->i_ctime = CURRENT_TIME;
-	mark_inode_dirty(inode);
-	atomic_inc(&inode->i_count);
-	d_instantiate(dentry, inode);
-	return 0;
+	inode->i_ctime = dir->i_ctime;
+	ext2_dec_count(inode);
+	err = 0;
+out:
+	return err;
 }
 
-#define PARENT_INO(buffer) \
-	((struct ext2_dir_entry_2 *) ((char *) buffer + \
-	le16_to_cpu(((struct ext2_dir_entry_2 *) buffer)->rec_len)))->inode
-
-/*
- * Anybody can rename anything with this: the permission checks are left to the
- * higher-level routines.
- */
-static int ext2_rename (struct inode * old_dir, struct dentry *old_dentry,
-			   struct inode * new_dir,struct dentry *new_dentry)
+static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
 {
-	struct inode * old_inode, * new_inode;
-	struct buffer_head * old_bh, * new_bh, * dir_bh;
-	struct ext2_dir_entry_2 * old_de, * new_de;
-	int retval;
-
-	old_bh = new_bh = dir_bh = NULL;
-
-	old_bh = ext2_find_entry (old_dir, old_dentry->d_name.name, old_dentry->d_name.len, &old_de);
-	/*
-	 *  Check for inode number is _not_ due to possible IO errors.
-	 *  We might rmdir the source, keep it as pwd of some process
-	 *  and merrily kill the link to whatever was created under the
-	 *  same name. Goodbye sticky bit ;-<
-	 */
-	old_inode = old_dentry->d_inode;
-	retval = -ENOENT;
-	if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
-		goto end_rename;
-
-	new_inode = new_dentry->d_inode;
-	new_bh = ext2_find_entry (new_dir, new_dentry->d_name.name,
-				new_dentry->d_name.len, &new_de);
-	if (new_bh) {
-		if (!new_inode) {
-			brelse (new_bh);
-			new_bh = NULL;
-		} else {
-			DQUOT_INIT(new_inode);
+	struct inode * inode = dentry->d_inode;
+	int err = -ENOTEMPTY;
+
+	if (ext2_empty_dir(inode)) {
+		err = ext2_unlink(dir, dentry);
+		if (!err) {
+			inode->i_size = 0;
+			ext2_dec_count(inode);
+			ext2_dec_count(dir);
 		}
 	}
+	return err;
+}
+
+static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
+	struct inode * new_dir,	struct dentry * new_dentry )
+{
+	struct inode * old_inode = old_dentry->d_inode;
+	struct inode * new_inode = new_dentry->d_inode;
+	struct page * dir_page = NULL;
+	struct ext2_dir_entry_2 * dir_de = NULL;
+	struct page * old_page;
+	struct ext2_dir_entry_2 * old_de;
+	int err = -ENOENT;
+
+	old_de = ext2_find_entry (old_dir, old_dentry, &old_page);
+	if (!old_de)
+		goto out;
+
 	if (S_ISDIR(old_inode->i_mode)) {
-		if (new_inode) {
-			retval = -ENOTEMPTY;
-			if (!empty_dir (new_inode))
-				goto end_rename;
-		}
-		retval = -EIO;
-		dir_bh = ext2_bread (old_inode, 0, 0, &retval);
-		if (!dir_bh)
-			goto end_rename;
-		if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
-			goto end_rename;
-		retval = -EMLINK;
-		if (!new_inode && new_dir!=old_dir &&
-				new_dir->i_nlink >= EXT2_LINK_MAX)
-			goto end_rename;
+		err = -EIO;
+		dir_de = ext2_dotdot(old_inode, &dir_page);
+		if (!dir_de)
+			goto out_old;
 	}
-	if (!new_bh) {
-		retval = ext2_add_entry (new_dir, new_dentry->d_name.name,
-					 new_dentry->d_name.len,
-					 old_inode);
-		if (retval)
-			goto end_rename;
-	} else {
-		new_de->inode = le32_to_cpu(old_inode->i_ino);
-		if (EXT2_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
-					      EXT2_FEATURE_INCOMPAT_FILETYPE))
-			new_de->file_type = old_de->file_type;
-		new_dir->i_version = ++event;
-		mark_buffer_dirty_inode(new_bh, new_dir);
-		if (IS_SYNC(new_dir)) {
-			ll_rw_block (WRITE, 1, &new_bh);
-			wait_on_buffer (new_bh);
-		}
-		brelse(new_bh);
-		new_bh = NULL;
-	}
-	
-	/*
-	 * Like most other Unix systems, set the ctime for inodes on a
-	 * rename.
-	 */
-	old_inode->i_ctime = CURRENT_TIME;
-	mark_inode_dirty(old_inode);
-
-	/*
-	 * ok, that's it
-	 */
-	ext2_delete_entry(old_dir, old_de, old_bh);
 
 	if (new_inode) {
-		new_inode->i_nlink--;
+		struct page *new_page;
+		struct ext2_dir_entry_2 *new_de;
+
+		err = -ENOTEMPTY;
+		if (dir_de && !ext2_empty_dir (new_inode))
+			goto out_dir;
+
+		err = -ENOENT;
+		new_de = ext2_find_entry (new_dir, new_dentry, &new_page);
+		if (!new_de)
+			goto out_dir;
+		ext2_inc_count(old_inode);
+		ext2_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME;
-		mark_inode_dirty(new_inode);
-	}
-	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
-	old_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-	mark_inode_dirty(old_dir);
-	if (dir_bh) {
-		PARENT_INO(dir_bh->b_data) = le32_to_cpu(new_dir->i_ino);
-		mark_buffer_dirty_inode(dir_bh, old_inode);
-		old_dir->i_nlink--;
-		mark_inode_dirty(old_dir);
-		if (new_inode) {
+		if (dir_de)
 			new_inode->i_nlink--;
-			mark_inode_dirty(new_inode);
-		} else {
-			new_dir->i_nlink++;
-			new_dir->u.ext2_i.i_flags &= ~EXT2_BTREE_FL;
-			mark_inode_dirty(new_dir);
-		}
+		ext2_dec_count(new_inode);
+	} else {
+		if (dir_de) {
+			err = -EMLINK;
+			if (new_dir->i_nlink >= EXT2_LINK_MAX)
+				goto out_dir;
+		}
+		ext2_inc_count(old_inode);
+		err = ext2_add_link(new_dentry, old_inode);
+		if (err) {
+			ext2_dec_count(old_inode);
+			goto out_dir;
+		}
+		if (dir_de)
+			ext2_inc_count(new_dir);
+	}
+
+	ext2_delete_entry (old_de, old_page);
+	ext2_dec_count(old_inode);
+
+	if (dir_de) {
+		ext2_set_link(old_inode, dir_de, dir_page, new_dir);
+		ext2_dec_count(old_dir);
 	}
+	return 0;
 
-	retval = 0;
 
-end_rename:
-	brelse (dir_bh);
-	brelse (old_bh);
-	brelse (new_bh);
-	return retval;
+out_dir:
+	if (dir_de) {
+		kunmap(dir_page);
+		page_cache_release(dir_page);
+	}
+out_old:
+	kunmap(old_page);
+	page_cache_release(old_page);
+out:
+	return err;
 }
 
-/*
- * directories can handle most operations...
- */
 struct inode_operations ext2_dir_inode_operations = {
 	create:		ext2_create,
 	lookup:		ext2_lookup,