1 files changed, 418 insertions, 0 deletions
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
new file mode 100644
index 00000000000..3176b3d3ffa
--- /dev/null
+++ b/fs/ext2/namei.c
@@ -0,0 +1,418 @@
+/*
+ * 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@parcelfarce.linux.theplanet.co.uk
+ *
+ * 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)
+ * 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
+ */
+
+#include <linux/pagemap.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Couple of helper functions - make the code slightly cleaner.
+ */
+
+static inline void ext2_inc_count(struct inode *inode)
+{
+	inode->i_nlink++;
+	mark_inode_dirty(inode);
+}
+
+static inline void ext2_dec_count(struct inode *inode)
+{
+	inode->i_nlink--;
+	mark_inode_dirty(inode);
+}
+
+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;
+	}
+	ext2_dec_count(inode);
+	iput(inode);
+	return err;
+}
+
+/*
+ * Methods themselves.
+ */
+
+static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+	struct inode * inode;
+	ino_t ino;
+	
+	if (dentry->d_name.len > EXT2_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	ino = ext2_inode_by_name(dir, dentry);
+	inode = NULL;
+	if (ino) {
+		inode = iget(dir->i_sb, ino);
+		if (!inode)
+			return ERR_PTR(-EACCES);
+	}
+	if (inode)
+		return d_splice_alias(inode, dentry);
+	d_add(dentry, inode);
+	return NULL;
+}
+
+struct dentry *ext2_get_parent(struct dentry *child)
+{
+	unsigned long ino;
+	struct dentry *parent;
+	struct inode *inode;
+	struct dentry dotdot;
+
+	dotdot.d_name.name = "..";
+	dotdot.d_name.len = 2;
+
+	ino = ext2_inode_by_name(child->d_inode, &dotdot);
+	if (!ino)
+		return ERR_PTR(-ENOENT);
+	inode = iget(child->d_inode->i_sb, ino);
+
+	if (!inode)
+		return ERR_PTR(-EACCES);
+	parent = d_alloc_anon(inode);
+	if (!parent) {
+		iput(inode);
+		parent = ERR_PTR(-ENOMEM);
+	}
+	return parent;
+} 
+
+/*
+ * 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 ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
+{
+	struct inode * inode = ext2_new_inode (dir, mode);
+	int err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		inode->i_op = &ext2_file_inode_operations;
+		inode->i_fop = &ext2_file_operations;
+		if (test_opt(inode->i_sb, NOBH))
+			inode->i_mapping->a_ops = &ext2_nobh_aops;
+		else
+			inode->i_mapping->a_ops = &ext2_aops;
+		mark_inode_dirty(inode);
+		err = ext2_add_nondir(dentry, inode);
+	}
+	return err;
+}
+
+static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
+{
+	struct inode * inode;
+	int err;
+
+	if (!new_valid_dev(rdev))
+		return -EINVAL;
+
+	inode = ext2_new_inode (dir, mode);
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		init_special_inode(inode, inode->i_mode, rdev);
+#ifdef CONFIG_EXT2_FS_XATTR
+		inode->i_op = &ext2_special_inode_operations;
+#endif
+		mark_inode_dirty(inode);
+		err = ext2_add_nondir(dentry, inode);
+	}
+	return err;
+}
+
+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;
+
+	if (l > sb->s_blocksize)
+		goto out;
+
+	inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
+	err = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out;
+
+	if (l > sizeof (EXT2_I(inode)->i_data)) {
+		/* slow symlink */
+		inode->i_op = &ext2_symlink_inode_operations;
+		if (test_opt(inode->i_sb, NOBH))
+			inode->i_mapping->a_ops = &ext2_nobh_aops;
+		else
+			inode->i_mapping->a_ops = &ext2_aops;
+		err = page_symlink(inode, symname, l);
+		if (err)
+			goto out_fail;
+	} else {
+		/* fast symlink */
+		inode->i_op = &ext2_fast_symlink_inode_operations;
+		memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
+		inode->i_size = l-1;
+	}
+	mark_inode_dirty(inode);
+
+	err = ext2_add_nondir(dentry, inode);
+out:
+	return err;
+
+out_fail:
+	ext2_dec_count(inode);
+	iput (inode);
+	goto out;
+}
+
+static int ext2_link (struct dentry * old_dentry, struct inode * dir,
+	struct dentry *dentry)
+{
+	struct inode *inode = old_dentry->d_inode;
+
+	if (inode->i_nlink >= EXT2_LINK_MAX)
+		return -EMLINK;
+
+	inode->i_ctime = CURRENT_TIME_SEC;
+	ext2_inc_count(inode);
+	atomic_inc(&inode->i_count);
+
+	return ext2_add_nondir(dentry, inode);
+}
+
+static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+	struct inode * inode;
+	int err = -EMLINK;
+
+	if (dir->i_nlink >= EXT2_LINK_MAX)
+		goto out;
+
+	ext2_inc_count(dir);
+
+	inode = ext2_new_inode (dir, S_IFDIR | mode);
+	err = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_dir;
+
+	inode->i_op = &ext2_dir_inode_operations;
+	inode->i_fop = &ext2_dir_operations;
+	if (test_opt(inode->i_sb, NOBH))
+		inode->i_mapping->a_ops = &ext2_nobh_aops;
+	else
+		inode->i_mapping->a_ops = &ext2_aops;
+
+	ext2_inc_count(inode);
+
+	err = ext2_make_empty(inode, dir);
+	if (err)
+		goto out_fail;
+
+	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_unlink(struct inode * dir, struct dentry *dentry)
+{
+	struct inode * inode = dentry->d_inode;
+	struct ext2_dir_entry_2 * de;
+	struct page * page;
+	int err = -ENOENT;
+
+	de = ext2_find_entry (dir, dentry, &page);
+	if (!de)
+		goto out;
+
+	err = ext2_delete_entry (de, page);
+	if (err)
+		goto out;
+
+	inode->i_ctime = dir->i_ctime;
+	ext2_dec_count(inode);
+	err = 0;
+out:
+	return err;
+}
+
+static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
+{
+	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)) {
+		err = -EIO;
+		dir_de = ext2_dotdot(old_inode, &dir_page);
+		if (!dir_de)
+			goto out_old;
+	}
+
+	if (new_inode) {
+		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_SEC;
+		if (dir_de)
+			new_inode->i_nlink--;
+		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);
+	}
+
+	/*
+	 * Like most other Unix systems, set the ctime for inodes on a
+ 	 * rename.
+	 * ext2_dec_count() will mark the inode dirty.
+	 */
+	old_inode->i_ctime = CURRENT_TIME_SEC;
+
+	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;
+
+
+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;
+}
+
+struct inode_operations ext2_dir_inode_operations = {
+	.create		= ext2_create,
+	.lookup		= ext2_lookup,
+	.link		= ext2_link,
+	.unlink		= ext2_unlink,
+	.symlink	= ext2_symlink,
+	.mkdir		= ext2_mkdir,
+	.rmdir		= ext2_rmdir,
+	.mknod		= ext2_mknod,
+	.rename		= ext2_rename,
+#ifdef CONFIG_EXT2_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext2_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+	.setattr	= ext2_setattr,
+	.permission	= ext2_permission,
+};
+
+struct inode_operations ext2_special_inode_operations = {
+#ifdef CONFIG_EXT2_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext2_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+	.setattr	= ext2_setattr,
+	.permission	= ext2_permission,
+};