patch-2.4.15 linux/fs/ext3/namei.c

• Lines: 1126
• Date: Fri Nov 9 14:25:04 2001
• Orig file: v2.4.14/linux/fs/ext3/namei.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.14/linux/fs/ext3/namei.c linux/fs/ext3/namei.c
@@ -0,0 +1,1125 @@
+/*
+ *  linux/fs/ext3/namei.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  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/jbd.h>
+#include <linux/sched.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/locks.h>
+#include <linux/quotaops.h>
+
+
+/*
+ * define how far ahead to read directories while searching them.
+ */
+#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, ext3_match returns 1 for success, 0 for failure.
+ *
+ * `len <= EXT3_NAME_LEN' is guaranteed by caller.
+ * `de != NULL' is guaranteed by caller.
+ */
+static inline int ext3_match (int len, const char * const name,
+			      struct ext3_dir_entry_2 * de)
+{
+	if (len != de->name_len)
+		return 0;
+	if (!de->inode)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+/*
+ * Returns 0 if not found, -1 on failure, and 1 on success
+ */
+static int inline search_dirblock(struct buffer_head * bh,
+				  struct inode *dir,
+				  struct dentry *dentry,
+				  unsigned long offset,
+				  struct ext3_dir_entry_2 ** res_dir)
+{
+	struct ext3_dir_entry_2 * de;
+	char * dlimit;
+	int de_len;
+	const char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+
+	de = (struct ext3_dir_entry_2 *) bh->b_data;
+	dlimit = bh->b_data + dir->i_sb->s_blocksize;
+	while ((char *) de < dlimit) {
+		/* this code is executed quadratically often */
+		/* do minimal checking `by hand' */
+
+		if ((char *) de + namelen <= dlimit &&
+		    ext3_match (namelen, name, de)) {
+			/* found a match - just to be sure, do a full check */
+			if (!ext3_check_dir_entry("ext3_find_entry",
+						  dir, de, bh, offset))
+				return -1;
+			*res_dir = de;
+			return 1;
+		}
+		/* prevent looping on a bad block */
+		de_len = le16_to_cpu(de->rec_len);
+		if (de_len <= 0)
+			return -1;
+		offset += de_len;
+		de = (struct ext3_dir_entry_2 *) ((char *) de + de_len);
+	}
+	return 0;
+}
+
+/*
+ *	ext3_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.
+ *
+ * The returned buffer_head has ->b_count elevated.  The caller is expected
+ * to brelse() it when appropriate.
+ */
+static struct buffer_head * ext3_find_entry (struct dentry *dentry,
+					struct ext3_dir_entry_2 ** res_dir)
+{
+	struct super_block * sb;
+	struct buffer_head * bh_use[NAMEI_RA_SIZE];
+	struct buffer_head * bh, *ret = NULL;
+	unsigned long start, block, b;
+	int ra_max = 0;		/* Number of bh's in the readahead
+				   buffer, bh_use[] */
+	int ra_ptr = 0;		/* Current index into readahead
+				   buffer */
+	int num = 0;
+	int nblocks, i, err;
+	struct inode *dir = dentry->d_parent->d_inode;
+
+	*res_dir = NULL;
+	sb = dir->i_sb;
+
+	nblocks = dir->i_size >> EXT3_BLOCK_SIZE_BITS(sb);
+	start = dir->u.ext3_i.i_dir_start_lookup;
+	if (start >= nblocks)
+		start = 0;
+	block = start;
+restart:
+	do {
+		/*
+		 * We deal with the read-ahead logic here.
+		 */
+		if (ra_ptr >= ra_max) {
+			/* Refill the readahead buffer */
+			ra_ptr = 0;
+			b = block;
+			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
+				/*
+				 * Terminate if we reach the end of the
+				 * directory and must wrap, or if our
+				 * search has finished at this block.
+				 */
+				if (b >= nblocks || (num && block == start)) {
+					bh_use[ra_max] = NULL;
+					break;
+				}
+				num++;
+				bh = ext3_getblk(NULL, dir, b++, 0, &err);
+				bh_use[ra_max] = bh;
+				if (bh)
+					ll_rw_block(READ, 1, &bh);
+			}
+		}
+		if ((bh = bh_use[ra_ptr++]) == NULL)
+			goto next;
+		wait_on_buffer(bh);
+		if (!buffer_uptodate(bh)) {
+			/* read error, skip block & hope for the best */
+			brelse(bh);
+			goto next;
+		}
+		i = search_dirblock(bh, dir, dentry,
+			    block << EXT3_BLOCK_SIZE_BITS(sb), res_dir);
+		if (i == 1) {
+			dir->u.ext3_i.i_dir_start_lookup = block;
+			ret = bh;
+			goto cleanup_and_exit;
+		} else {
+			brelse(bh);
+			if (i < 0)
+				goto cleanup_and_exit;
+		}
+	next:
+		if (++block >= nblocks)
+			block = 0;
+	} while (block != start);
+
+	/*
+	 * If the directory has grown while we were searching, then
+	 * search the last part of the directory before giving up.
+	 */
+	block = nblocks;
+	nblocks = dir->i_size >> EXT3_BLOCK_SIZE_BITS(sb);
+	if (block < nblocks) {
+		start = 0;
+		goto restart;
+	}
+		
+cleanup_and_exit:
+	/* Clean up the read-ahead blocks */
+	for (; ra_ptr < ra_max; ra_ptr++)
+		brelse (bh_use[ra_ptr]);
+	return ret;
+}
+
+static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry)
+{
+	struct inode * inode;
+	struct ext3_dir_entry_2 * de;
+	struct buffer_head * bh;
+
+	if (dentry->d_name.len > EXT3_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	bh = ext3_find_entry(dentry, &de);
+	inode = NULL;
+	if (bh) {
+		unsigned long ino = le32_to_cpu(de->inode);
+		brelse (bh);
+		inode = iget(dir->i_sb, ino);
+
+		if (!inode)
+			return ERR_PTR(-EACCES);
+	}
+	d_add(dentry, inode);
+	return NULL;
+}
+
+#define S_SHIFT 12
+static unsigned char ext3_type_by_mode[S_IFMT >> S_SHIFT] = {
+	[S_IFREG >> S_SHIFT]	EXT3_FT_REG_FILE,
+	[S_IFDIR >> S_SHIFT]	EXT3_FT_DIR,
+	[S_IFCHR >> S_SHIFT]	EXT3_FT_CHRDEV,
+	[S_IFBLK >> S_SHIFT]	EXT3_FT_BLKDEV,
+	[S_IFIFO >> S_SHIFT]	EXT3_FT_FIFO,
+	[S_IFSOCK >> S_SHIFT]	EXT3_FT_SOCK,
+	[S_IFLNK >> S_SHIFT]	EXT3_FT_SYMLINK,
+};
+
+static inline void ext3_set_de_type(struct super_block *sb,
+				struct ext3_dir_entry_2 *de,
+				umode_t mode) {
+	if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE))
+		de->file_type = ext3_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
+}
+
+/*
+ *	ext3_add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as ext3_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.
+ */
+
+/*
+ * AKPM: the journalling code here looks wrong on the error paths
+ */
+static int ext3_add_entry (handle_t *handle, struct dentry *dentry,
+	struct inode *inode)
+{
+	struct inode *dir = dentry->d_parent->d_inode;
+	const char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	unsigned long offset;
+	unsigned short rec_len;
+	struct buffer_head * bh;
+	struct ext3_dir_entry_2 * de, * de1;
+	struct super_block * sb;
+	int	retval;
+
+	sb = dir->i_sb;
+
+	if (!namelen)
+		return -EINVAL;
+	bh = ext3_bread (handle, dir, 0, 0, &retval);
+	if (!bh)
+		return retval;
+	rec_len = EXT3_DIR_REC_LEN(namelen);
+	offset = 0;
+	de = (struct ext3_dir_entry_2 *) bh->b_data;
+	while (1) {
+		if ((char *)de >= sb->s_blocksize + bh->b_data) {
+			brelse (bh);
+			bh = NULL;
+			bh = ext3_bread (handle, dir,
+				offset >> EXT3_BLOCK_SIZE_BITS(sb), 1, &retval);
+			if (!bh)
+				return retval;
+			if (dir->i_size <= offset) {
+				if (dir->i_size == 0) {
+					brelse(bh);
+					return -ENOENT;
+				}
+
+				ext3_debug ("creating next block\n");
+
+				BUFFER_TRACE(bh, "get_write_access");
+				ext3_journal_get_write_access(handle, bh);
+				de = (struct ext3_dir_entry_2 *) bh->b_data;
+				de->inode = 0;
+				de->rec_len = le16_to_cpu(sb->s_blocksize);
+				dir->u.ext3_i.i_disksize =
+					dir->i_size = offset + sb->s_blocksize;
+				dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+				ext3_mark_inode_dirty(handle, dir);
+			} else {
+
+				ext3_debug ("skipping to next block\n");
+
+				de = (struct ext3_dir_entry_2 *) bh->b_data;
+			}
+		}
+		if (!ext3_check_dir_entry ("ext3_add_entry", dir, de, bh,
+					   offset)) {
+			brelse (bh);
+			return -ENOENT;
+		}
+		if (ext3_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) >=
+				EXT3_DIR_REC_LEN(de->name_len) + rec_len)) {
+			BUFFER_TRACE(bh, "get_write_access");
+			ext3_journal_get_write_access(handle, bh);
+			/* By now the buffer is marked for journaling */
+			offset += le16_to_cpu(de->rec_len);
+			if (le32_to_cpu(de->inode)) {
+				de1 = (struct ext3_dir_entry_2 *) ((char *) de +
+					EXT3_DIR_REC_LEN(de->name_len));
+				de1->rec_len =
+					cpu_to_le16(le16_to_cpu(de->rec_len) -
+					EXT3_DIR_REC_LEN(de->name_len));
+				de->rec_len = cpu_to_le16(
+						EXT3_DIR_REC_LEN(de->name_len));
+				de = de1;
+			}
+			de->file_type = EXT3_FT_UNKNOWN;
+			if (inode) {
+				de->inode = cpu_to_le32(inode->i_ino);
+				ext3_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
+			 * ext3_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.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+			ext3_mark_inode_dirty(handle, dir);
+			dir->i_version = ++event;
+			BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+			ext3_journal_dirty_metadata(handle, bh);
+			brelse(bh);
+			return 0;
+		}
+		offset += le16_to_cpu(de->rec_len);
+		de = (struct ext3_dir_entry_2 *)
+			((char *) de + le16_to_cpu(de->rec_len));
+	}
+	brelse (bh);
+	return -ENOSPC;
+}
+
+/*
+ * ext3_delete_entry deletes a directory entry by merging it with the
+ * previous entry
+ */
+static int ext3_delete_entry (handle_t *handle, 
+			      struct inode * dir,
+			      struct ext3_dir_entry_2 * de_del,
+			      struct buffer_head * bh)
+{
+	struct ext3_dir_entry_2 * de, * pde;
+	int i;
+
+	i = 0;
+	pde = NULL;
+	de = (struct ext3_dir_entry_2 *) bh->b_data;
+	while (i < bh->b_size) {
+		if (!ext3_check_dir_entry("ext3_delete_entry", dir, de, bh, i))
+			return -EIO;
+		if (de == de_del)  {
+			BUFFER_TRACE(bh, "get_write_access");
+			ext3_journal_get_write_access(handle, bh);
+			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;
+			BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+			ext3_journal_dirty_metadata(handle, bh);
+			return 0;
+		}
+		i += le16_to_cpu(de->rec_len);
+		pde = de;
+		de = (struct ext3_dir_entry_2 *)
+			((char *) de + le16_to_cpu(de->rec_len));
+	}
+	return -ENOENT;
+}
+
+/*
+ * ext3_mark_inode_dirty is somewhat expensive, so unlike ext2 we
+ * do not perform it in these functions.  We perform it at the call site,
+ * if it is needed.
+ */
+static inline void ext3_inc_count(handle_t *handle, struct inode *inode)
+{
+	inode->i_nlink++;
+}
+
+static inline void ext3_dec_count(handle_t *handle, struct inode *inode)
+{
+	inode->i_nlink--;
+}
+
+static int ext3_add_nondir(handle_t *handle,
+		struct dentry *dentry, struct inode *inode)
+{
+	int err = ext3_add_entry(handle, dentry, inode);
+	if (!err) {
+		d_instantiate(dentry, inode);
+		return 0;
+	}
+	ext3_dec_count(handle, inode);
+	iput(inode);
+	return err;
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate(). 
+ */
+static int ext3_create (struct inode * dir, struct dentry * dentry, int mode)
+{
+	handle_t *handle; 
+	struct inode * inode;
+	int err;
+
+	handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS + 3);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	inode = ext3_new_inode (handle, dir, mode);
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		inode->i_op = &ext3_file_inode_operations;
+		inode->i_fop = &ext3_file_operations;
+		inode->i_mapping->a_ops = &ext3_aops;
+		ext3_mark_inode_dirty(handle, inode);
+		err = ext3_add_nondir(handle, dentry, inode);
+	}
+	ext3_journal_stop(handle, dir);
+	return err;
+}
+
+static int ext3_mknod (struct inode * dir, struct dentry *dentry,
+			int mode, int rdev)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err;
+
+	handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS + 3);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	inode = ext3_new_inode (handle, dir, mode);
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		init_special_inode(inode, mode, rdev);
+		ext3_mark_inode_dirty(handle, inode);
+		err = ext3_add_nondir(handle, dentry, inode);
+	}
+	ext3_journal_stop(handle, dir);
+	return err;
+}
+
+static int ext3_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+	handle_t *handle;
+	struct inode * inode;
+	struct buffer_head * dir_block;
+	struct ext3_dir_entry_2 * de;
+	int err;
+
+	if (dir->i_nlink >= EXT3_LINK_MAX)
+		return -EMLINK;
+
+	handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS + 3);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	inode = ext3_new_inode (handle, dir, S_IFDIR);
+	err = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_stop;
+
+	inode->i_op = &ext3_dir_inode_operations;
+	inode->i_fop = &ext3_dir_operations;
+	inode->i_size = inode->u.ext3_i.i_disksize = inode->i_sb->s_blocksize;
+	inode->i_blocks = 0;	
+	dir_block = ext3_bread (handle, inode, 0, 1, &err);
+	if (!dir_block) {
+		inode->i_nlink--; /* is this nlink == 0? */
+		ext3_mark_inode_dirty(handle, inode);
+		iput (inode);
+		goto out_stop;
+	}
+	BUFFER_TRACE(dir_block, "get_write_access");
+	ext3_journal_get_write_access(handle, dir_block);
+	de = (struct ext3_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(EXT3_DIR_REC_LEN(de->name_len));
+	strcpy (de->name, ".");
+	ext3_set_de_type(dir->i_sb, de, S_IFDIR);
+	de = (struct ext3_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-EXT3_DIR_REC_LEN(1));
+	de->name_len = 2;
+	strcpy (de->name, "..");
+	ext3_set_de_type(dir->i_sb, de, S_IFDIR);
+	inode->i_nlink = 2;
+	BUFFER_TRACE(dir_block, "call ext3_journal_dirty_metadata");
+	ext3_journal_dirty_metadata(handle, dir_block);
+	brelse (dir_block);
+	inode->i_mode = S_IFDIR | mode;
+	if (dir->i_mode & S_ISGID)
+		inode->i_mode |= S_ISGID;
+	ext3_mark_inode_dirty(handle, inode);
+	err = ext3_add_entry (handle, dentry, inode);
+	if (err)
+		goto out_no_entry;
+	dir->i_nlink++;
+	dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+	ext3_mark_inode_dirty(handle, dir);
+	d_instantiate(dentry, inode);
+out_stop:
+	ext3_journal_stop(handle, dir);
+	return err;
+
+out_no_entry:
+	inode->i_nlink = 0;
+	ext3_mark_inode_dirty(handle, inode);
+	iput (inode);
+	goto out_stop;
+}
+
+/*
+ * 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 ext3_dir_entry_2 * de, * de1;
+	struct super_block * sb;
+	int err;
+
+	sb = inode->i_sb;
+	if (inode->i_size < EXT3_DIR_REC_LEN(1) + EXT3_DIR_REC_LEN(2) ||
+	    !(bh = ext3_bread (NULL, inode, 0, 0, &err))) {
+	    	ext3_warning (inode->i_sb, "empty_dir",
+			      "bad directory (dir #%lu) - no data block",
+			      inode->i_ino);
+		return 1;
+	}
+	de = (struct ext3_dir_entry_2 *) bh->b_data;
+	de1 = (struct ext3_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)) {
+	    	ext3_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 ext3_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 = ext3_bread (NULL, inode,
+				offset >> EXT3_BLOCK_SIZE_BITS(sb), 0, &err);
+			if (!bh) {
+#if 0
+				ext3_error (sb, "empty_dir",
+				"directory #%lu contains a hole at offset %lu",
+					inode->i_ino, offset);
+#endif
+				offset += sb->s_blocksize;
+				continue;
+			}
+			de = (struct ext3_dir_entry_2 *) bh->b_data;
+		}
+		if (!ext3_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 ext3_dir_entry_2 *)
+				((char *) de + le16_to_cpu(de->rec_len));
+	}
+	brelse (bh);
+	return 1;
+}
+
+/* ext3_orphan_add() links an unlinked or truncated inode into a list of
+ * such inodes, starting at the superblock, in case we crash before the
+ * file is closed/deleted, or in case the inode truncate spans multiple
+ * transactions and the last transaction is not recovered after a crash.
+ *
+ * At filesystem recovery time, we walk this list deleting unlinked
+ * inodes and truncating linked inodes in ext3_orphan_cleanup().
+ */
+int ext3_orphan_add(handle_t *handle, struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct ext3_iloc iloc;
+	int err = 0, rc;
+	
+	lock_super(sb);
+	if (!list_empty(&inode->u.ext3_i.i_orphan))
+		goto out_unlock;
+
+	/* Orphan handling is only valid for files with data blocks
+	 * being truncated, or files being unlinked. */
+
+	/* @@@ FIXME: Observation from aviro:
+	 * I think I can trigger J_ASSERT in ext3_orphan_add().  We block 
+	 * here (on lock_super()), so race with ext3_link() which might bump
+	 * ->i_nlink. For, say it, character device. Not a regular file,
+	 * not a directory, not a symlink and ->i_nlink > 0.
+	 */
+	J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+		S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
+
+	BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get_write_access");
+	err = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh);
+	if (err)
+		goto out_unlock;
+	
+	err = ext3_reserve_inode_write(handle, inode, &iloc);
+	if (err)
+		goto out_unlock;
+
+	/* Insert this inode at the head of the on-disk orphan list... */
+	NEXT_ORPHAN(inode) = le32_to_cpu(EXT3_SB(sb)->s_es->s_last_orphan);
+	EXT3_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
+	err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh);
+	rc = ext3_mark_iloc_dirty(handle, inode, &iloc);
+	if (!err)
+		err = rc;
+
+	/* Only add to the head of the in-memory list if all the
+	 * previous operations succeeded.  If the orphan_add is going to
+	 * fail (possibly taking the journal offline), we can't risk
+	 * leaving the inode on the orphan list: stray orphan-list
+	 * entries can cause panics at unmount time.
+	 *
+	 * This is safe: on error we're going to ignore the orphan list
+	 * anyway on the next recovery. */
+	if (!err)
+		list_add(&inode->u.ext3_i.i_orphan, &EXT3_SB(sb)->s_orphan);
+
+	jbd_debug(4, "superblock will point to %ld\n", inode->i_ino);
+	jbd_debug(4, "orphan inode %ld will point to %d\n",
+			inode->i_ino, NEXT_ORPHAN(inode));
+out_unlock:
+	unlock_super(sb);
+	ext3_std_error(inode->i_sb, err);
+	return err;
+}
+
+/*
+ * ext3_orphan_del() removes an unlinked or truncated inode from the list
+ * of such inodes stored on disk, because it is finally being cleaned up.
+ */
+int ext3_orphan_del(handle_t *handle, struct inode *inode)
+{
+	struct list_head *prev;
+	struct ext3_sb_info *sbi;
+	ino_t ino_next; 
+	struct ext3_iloc iloc;
+	int err = 0;
+	
+	lock_super(inode->i_sb);
+	if (list_empty(&inode->u.ext3_i.i_orphan)) {
+		unlock_super(inode->i_sb);
+		return 0;
+	}
+
+	ino_next = NEXT_ORPHAN(inode);
+	prev = inode->u.ext3_i.i_orphan.prev;
+	sbi = EXT3_SB(inode->i_sb);
+
+	jbd_debug(4, "remove inode %ld from orphan list\n", inode->i_ino);
+
+	list_del(&inode->u.ext3_i.i_orphan);
+	INIT_LIST_HEAD(&inode->u.ext3_i.i_orphan);
+
+	/* If we're on an error path, we may not have a valid
+	 * transaction handle with which to update the orphan list on
+	 * disk, but we still need to remove the inode from the linked
+	 * list in memory. */
+	if (!handle)
+		goto out;
+	
+	err = ext3_reserve_inode_write(handle, inode, &iloc);
+	if (err)
+		goto out_err;
+
+	if (prev == &sbi->s_orphan) {
+		jbd_debug(4, "superblock will point to %ld\n", ino_next);
+		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+		err = ext3_journal_get_write_access(handle, sbi->s_sbh);
+		if (err)
+			goto out_brelse;
+		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
+		err = ext3_journal_dirty_metadata(handle, sbi->s_sbh);
+	} else {
+		struct ext3_iloc iloc2;
+		struct inode *i_prev =
+			list_entry(prev, struct inode, u.ext3_i.i_orphan);
+		
+		jbd_debug(4, "orphan inode %ld will point to %ld\n",
+			  i_prev->i_ino, ino_next);
+		err = ext3_reserve_inode_write(handle, i_prev, &iloc2);
+		if (err)
+			goto out_brelse;
+		NEXT_ORPHAN(i_prev) = ino_next;
+		err = ext3_mark_iloc_dirty(handle, i_prev, &iloc2);
+	}
+	if (err)
+		goto out_brelse;
+	NEXT_ORPHAN(inode) = 0;
+	err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+	if (err)
+		goto out_brelse;
+
+out_err: 	
+	ext3_std_error(inode->i_sb, err);
+out:
+	unlock_super(inode->i_sb);
+	return err;
+
+out_brelse:
+	brelse(iloc.bh);
+	goto out_err;
+}
+
+static int ext3_rmdir (struct inode * dir, struct dentry *dentry)
+{
+	int retval;
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext3_dir_entry_2 * de;
+	handle_t *handle;
+
+	handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	retval = -ENOENT;
+	bh = ext3_find_entry (dentry, &de);
+	if (!bh)
+		goto end_rmdir;
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	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 = ext3_delete_entry(handle, dir, de, bh);
+	if (retval)
+		goto end_rmdir;
+	if (inode->i_nlink != 2)
+		ext3_warning (inode->i_sb, "ext3_rmdir",
+			      "empty directory has nlink!=2 (%d)",
+			      inode->i_nlink);
+	inode->i_version = ++event;
+	inode->i_nlink = 0;
+	/* There's no need to set i_disksize: the fact that i_nlink is
+	 * zero will ensure that the right thing happens during any
+	 * recovery. */
+	inode->i_size = 0;
+	ext3_orphan_add(handle, inode);
+	ext3_mark_inode_dirty(handle, inode);
+	dir->i_nlink--;
+	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+	ext3_mark_inode_dirty(handle, dir);
+
+end_rmdir:
+	ext3_journal_stop(handle, dir);
+	brelse (bh);
+	return retval;
+}
+
+static int ext3_unlink(struct inode * dir, struct dentry *dentry)
+{
+	int retval;
+	struct inode * inode;
+	struct buffer_head * bh;
+	struct ext3_dir_entry_2 * de;
+	handle_t *handle;
+
+	handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	retval = -ENOENT;
+	bh = ext3_find_entry (dentry, &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) {
+		ext3_warning (inode->i_sb, "ext3_unlink",
+			      "Deleting nonexistent file (%lu), %d",
+			      inode->i_ino, inode->i_nlink);
+		inode->i_nlink = 1;
+	}
+	retval = ext3_delete_entry(handle, dir, de, bh);
+	if (retval)
+		goto end_unlink;
+	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+	ext3_mark_inode_dirty(handle, dir);
+	inode->i_nlink--;
+	if (!inode->i_nlink)
+		ext3_orphan_add(handle, inode);
+	ext3_mark_inode_dirty(handle, inode);
+	inode->i_ctime = dir->i_ctime;
+	retval = 0;
+
+end_unlink:
+	ext3_journal_stop(handle, dir);
+	brelse (bh);
+	return retval;
+}
+
+static int ext3_symlink (struct inode * dir,
+		struct dentry *dentry, const char * symname)
+{
+	handle_t *handle;
+	struct inode * inode;
+	int l, err;
+
+	l = strlen(symname)+1;
+	if (l > dir->i_sb->s_blocksize)
+		return -ENAMETOOLONG;
+
+	handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS + 5);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	inode = ext3_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
+	err = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_stop;
+
+	if (l > sizeof (inode->u.ext3_i.i_data)) {
+		inode->i_op = &page_symlink_inode_operations;
+		inode->i_mapping->a_ops = &ext3_aops;
+		/*
+		 * block_symlink() calls back into ext3_prepare/commit_write.
+		 * We have a transaction open.  All is sweetness.  It also sets
+		 * i_size in generic_commit_write().
+		 */
+		err = block_symlink(inode, symname, l);
+		if (err)
+			goto out_no_entry;
+	} else {
+		inode->i_op = &ext3_fast_symlink_inode_operations;
+		memcpy((char*)&inode->u.ext3_i.i_data,symname,l);
+		inode->i_size = l-1;
+	}
+	inode->u.ext3_i.i_disksize = inode->i_size;
+	ext3_mark_inode_dirty(handle, inode);
+	err = ext3_add_nondir(handle, dentry, inode);
+out_stop:
+	ext3_journal_stop(handle, dir);
+	return err;
+
+out_no_entry:
+	ext3_dec_count(handle, inode);
+	ext3_mark_inode_dirty(handle, inode);
+	iput (inode);
+	goto out_stop;
+}
+
+static int ext3_link (struct dentry * old_dentry,
+		struct inode * dir, struct dentry *dentry)
+{
+	handle_t *handle;
+	struct inode *inode = old_dentry->d_inode;
+	int err;
+
+	if (S_ISDIR(inode->i_mode))
+		return -EPERM;
+
+	if (inode->i_nlink >= EXT3_LINK_MAX)
+		return -EMLINK;
+
+	handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(dir))
+		handle->h_sync = 1;
+
+	inode->i_ctime = CURRENT_TIME;
+	ext3_inc_count(handle, inode);
+	atomic_inc(&inode->i_count);
+
+	ext3_mark_inode_dirty(handle, inode);
+	err = ext3_add_nondir(handle, dentry, inode);
+	ext3_journal_stop(handle, dir);
+	return err;
+}
+
+#define PARENT_INO(buffer) \
+	((struct ext3_dir_entry_2 *) ((char *) buffer + \
+	le16_to_cpu(((struct ext3_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 ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
+			   struct inode * new_dir,struct dentry *new_dentry)
+{
+	handle_t *handle;
+	struct inode * old_inode, * new_inode;
+	struct buffer_head * old_bh, * new_bh, * dir_bh;
+	struct ext3_dir_entry_2 * old_de, * new_de;
+	int retval;
+
+	old_bh = new_bh = dir_bh = NULL;
+
+	handle = ext3_journal_start(old_dir, 2 * EXT3_DATA_TRANS_BLOCKS + 2);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_SYNC(old_dir) || IS_SYNC(new_dir))
+		handle->h_sync = 1;
+
+	old_bh = ext3_find_entry (old_dentry, &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 = ext3_find_entry (new_dentry, &new_de);
+	if (new_bh) {
+		if (!new_inode) {
+			brelse (new_bh);
+			new_bh = NULL;
+		} else {
+			DQUOT_INIT(new_inode);
+		}
+	}
+	if (S_ISDIR(old_inode->i_mode)) {
+		if (new_inode) {
+			retval = -ENOTEMPTY;
+			if (!empty_dir (new_inode))
+				goto end_rename;
+		}
+		retval = -EIO;
+		dir_bh = ext3_bread (handle, 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 >= EXT3_LINK_MAX)
+			goto end_rename;
+	}
+	if (!new_bh) {
+		retval = ext3_add_entry (handle, new_dentry, old_inode);
+		if (retval)
+			goto end_rename;
+	} else {
+		BUFFER_TRACE(new_bh, "get write access");
+		BUFFER_TRACE(new_bh, "get_write_access");
+		ext3_journal_get_write_access(handle, new_bh);
+		new_de->inode = le32_to_cpu(old_inode->i_ino);
+		if (EXT3_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
+					      EXT3_FEATURE_INCOMPAT_FILETYPE))
+			new_de->file_type = old_de->file_type;
+		new_dir->i_version = ++event;
+		BUFFER_TRACE(new_bh, "call ext3_journal_dirty_metadata");
+		ext3_journal_dirty_metadata(handle, 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;
+	ext3_mark_inode_dirty(handle, old_inode);
+
+	/*
+	 * ok, that's it
+	 */
+	ext3_delete_entry(handle, old_dir, old_de, old_bh);
+
+	if (new_inode) {
+		new_inode->i_nlink--;
+		new_inode->i_ctime = CURRENT_TIME;
+	}
+	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
+	old_dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+	if (dir_bh) {
+		BUFFER_TRACE(dir_bh, "get_write_access");
+		ext3_journal_get_write_access(handle, dir_bh);
+		PARENT_INO(dir_bh->b_data) = le32_to_cpu(new_dir->i_ino);
+		BUFFER_TRACE(dir_bh, "call ext3_journal_dirty_metadata");
+		ext3_journal_dirty_metadata(handle, dir_bh);
+		old_dir->i_nlink--;
+		if (new_inode) {
+			new_inode->i_nlink--;
+		} else {
+			new_dir->i_nlink++;
+			new_dir->u.ext3_i.i_flags &= ~EXT3_INDEX_FL;
+			ext3_mark_inode_dirty(handle, new_dir);
+		}
+	}
+	ext3_mark_inode_dirty(handle, old_dir);
+	if (new_inode) {
+		ext3_mark_inode_dirty(handle, new_inode);
+		if (!new_inode->i_nlink)
+			ext3_orphan_add(handle, new_inode);
+	}
+	retval = 0;
+
+end_rename:
+	brelse (dir_bh);
+	brelse (old_bh);
+	brelse (new_bh);
+	ext3_journal_stop(handle, old_dir);
+	return retval;
+}
+
+/*
+ * directories can handle most operations...
+ */
+struct inode_operations ext3_dir_inode_operations = {
+	create:		ext3_create,		/* BKL held */
+	lookup:		ext3_lookup,		/* BKL held */
+	link:		ext3_link,		/* BKL held */
+	unlink:		ext3_unlink,		/* BKL held */
+	symlink:	ext3_symlink,		/* BKL held */
+	mkdir:		ext3_mkdir,		/* BKL held */
+	rmdir:		ext3_rmdir,		/* BKL held */
+	mknod:		ext3_mknod,		/* BKL held */
+	rename:		ext3_rename,		/* BKL held */
+};