o Kill write funcs for error/status files

o Redo write logic for table file
 o Relax rules for symlink content by removing the rewriting function

Well I probably won't get a chance to work on this tomorrow, so this is my
changeset to date.

driver/device-mapper/dmfs-error.c

@@ -28,13 +28,6 @@ static ssize_t dmfs_error_read(struct file *file, char *buf, size_t size, loff_t
 	return size;
 }
 
-static ssize_t dmfs_error_write(struct file *file, const char *buf, size_t size, loff_t *pos)
-{
-	struct inode *inode = file->f_dentry->d_inode;
-
-	return size;
-}
-
 static int dmfs_error_sync(struct file *file, struct dentry *dentry, int datasync)
 {
 	return 0;
@@ -42,7 +35,6 @@ static int dmfs_error_sync(struct file *file, struct dentry *dentry, int datasyn
 
 static struct dm_table_file_operations = {
 	read:		dmfs_error_read,
-	write:		dmfs_error_write,
 	fsync:		dmfs_error_sync,
 };
 

driver/device-mapper/dmfs-lv.c

@@ -33,38 +33,25 @@ struct dentry *dmfs_verify_name(struct inode *dir, char *name)
 	int err = -ENOENT;
 
 	if (path_init(name, LOOKUP_FOLLOW, &nd))
-		err = path_walk(path, &nd);
+		return ERR_PTR(-EINVAL);
 
+	err = path_walk(path, &nd);
 	if (err)
-		return ERR_PTR(err);
+		goto err_out;
 
+	err = -EINVAL;
 	if (nd.mnt->mnt->sb != dir->i_sb)
-		goto err;
+		goto err_out;
 
 	if (nd.dentry->d_parent != dir)
-		goto err;
+		goto err_out;
 
 	dget(nd.dentry);
 	path_release(nd);
 	return nd.dentry;
-err:
+err_out:
 	path_release(nd);
-	return ERR_PTR(-EINVAL);
+	return ERR_PTR(err);
-}
-
-char *dmfs_translate_name(struct dentry *de)
-{
-	int len = de->d_name.len + 3;
-	char *n = kmalloc(len);
-	if (n) {
-		char *p = n;
-		*p++ = '.';
-		*p++ = '/';
-		memcmp(p, de->d_name.name, de->d_name.len);
-		p += de->d_name.len
-		*p = 0;
-	}
-	return n;
 }
 
 struct inode *dmfs_create_symlink(struct inode *dir, int mode)
@@ -91,7 +78,6 @@ static int dmfs_lv_symlink(struct inode *dir, struct dentry *dentry,
 {
 	struct inode *inode;
 	struct dentry *de;
-	char *realname;
 	int rv;
 	int l;
 
@@ -99,11 +85,6 @@ static int dmfs_lv_symlink(struct inode *dir, struct dentry *dentry,
 	if (IS_ERR(de))
 		return PTR_ERR(de);
 
-	realname = dmfs_translate_name(de);
-	dput(de);
-	if (realname == NULL);
-		return -ENOMEM;
-
 	inode = dmfs_create_symlink(dir, S_IRWXUGO);
 	if (IS_ERR(inode)) {
 		kfree(realname);
@@ -113,12 +94,11 @@ static int dmfs_lv_symlink(struct inode *dir, struct dentry *dentry,
 	d_instantiate(dentry, inode);
 	dget(dentry);
 
-	l = strlen(realname) + 1;
+	l = strlen(symname) + 1;
-	rv = block_symlink(inode, realname, l);
+	rv = block_symlink(inode, symname, l);
 	if (rv) {
 		dput(dentry);
 	}
-	kfree(realname);
 
 	return rv;
 }
@@ -218,16 +198,6 @@ static struct dentry *dmfs_lv_lookup(struct inode *dir, struct dentry *dentry)
 	return NULL;
 }
 
-static int dmfs_lv_rename(struct inode *old_dir, struct dentry *old_dentry,
-			struct inode *new_dir, struct dentry *new_dentry)
-{
-	/* Can only rename - not move between directories! */
-	if (old_dir != new_dir)
-		return -EPERM;
-
-	return -EINVAL; /* FIXME: a change of LV name here */
-}
-
 static int dmfs_lv_sync(struct file *file, struct dentry *dentry, int datasync)
 {
 	return 0;
@@ -245,7 +215,6 @@ static struct dm_root_inode_operations = {
 	symlink:	dmfs_lv_symlink,
 	mkdir:		dmfs_lv_mkdir,
 	rmdir:		dmfs_lv_rmdir,
-	rename:		dmfs_lv_rename,
 };
 
 struct inode *dmfs_create_lv(struct super_block *sb, int mode)

driver/device-mapper/dmfs-status.c

@@ -27,11 +27,6 @@ static ssize_t dmfs_status_read(struct file *file, char *buf, size_t size, loff_
 	return size;
 }
 
-static ssize_t dmfs_status_write(struct file *file, const char *buf, size_t size, loff_t *pos)
-{
-	return size;
-}
-
 static int dmfs_status_sync(struct file *file, struct dentry *dentry, int datasync)
 {
 	return 0;
@@ -39,7 +34,6 @@ static int dmfs_status_sync(struct file *file, struct dentry *dentry, int datasy
 
 static struct dm_table_file_operations = {
 	read:		dmfs_status_read,
-	write:		dmfs_status_write,
 	fsync:		dmfs_status_sync,
 };
 

driver/device-mapper/dmfs-table.c

@@ -252,6 +252,29 @@ static int dmfs_commit_write(struct file *file, struct page *page,
 	return 0;
 }
 
+static int dmfs_table_open(struct inode *inode, struct file *file)
+{
+	struct dentry *dentry = file->f_dentry;
+	struct inode *inode = dentry->d_parent->d_inode;
+
+	if (file->f_mode & FMODE_WRITE) {
+		if (get_write_access(inode))
+			return -EPERM;
+	}
+
+	return 0;
+}
+
+static int dmfs_table_release(struct inode *inode, struct file *file)
+{
+	if (file->f_mode & FMODE_WRITE) {
+		struct dentry *dentry = file->f_dentry;
+		struct inode *inode = dentry->d_parent->d_inode;
+
+		put_write_access(inode);
+	}
+}
+
 static int dmfs_table_sync(struct file *file, struct dentry *dentry, int datasync)
 {
 	return 0;
@@ -268,6 +291,8 @@ static struct dmfs_table_file_operations = {
  	llseek:		generic_file_llseek,
 	read:		generic_file_read,
 	write:		generic_file_write,
+	open:		dmfs_table_open,
+	release:	dmfs_table_release,
 	fsync:		dmfs_table_sync,
 	release:	dmfs_release,
 };

driver/device-mapper/dmfs-tdir.c

@@ -29,89 +29,18 @@ extern struct inode *dmfs_create_table(struct inode *, int);
 extern struct inode *dmfs_create_status(struct inode *, int);
 
 
-static inline positive(struct dentry *dentry)
+int dm_lock_tdir(struct dentry *dentry)
 {
-	return dentry->d_inode && !d_unhashed(dentry);
+	struct file file = { f_dentry: dentry };
-}
-
-static int dm_deny_write_access(struct dentry *dentry)
-{
-	struct file file { f_dentry: &dentry };
 
 	return deny_write_access(&file);
 }
 
-static void dm_allow_dentry_list(struct dentry *list[], int i)
+void dm_unlock_tdir(struct dentry *dentry)
 {
-	int x;
+	struct file file = { f_dentry: dentry };
-	for(x = 0; x < i; x++)
-		atomic_inc(&list[x]->d_inode->i_writecount);
-}
 
-static int dm_deny_dentry_list(struct dentry *list[], int i)
+	allow_write_access(&file);
-{
-	int x;
-	int rv;
-
-	for(x = 0; x < i; x++) {
-		rv = dm_deny_write_access(list[x]);
-		if (rv)
-			goto error:
-	}
-	return 0;
-error:
-	if (x > 0) {
-		dm_allow_dentry_list(list, x - 1);
-	}
-	return rv;
-}
-
-static int dm_child_list(struct dentry *de_list[], struct dentry *dentry)
-{
-	struct list_head *list;
-	int i = 0;
-	int rv;
-
-	spin_lock(&dcache_lock);
-	list = dentry->d_subdirs.next;
-
-	while(list != &dentry->d_subdirs) {
-		struct dentry *de = list_entry(list, struct dentry, d_child);
-
-		if (positive(de))
-			de_list[i++] = dget(de);
-		list = list->next;
-	}
-	spin_unlock(&dcache_lock);
-
-	return i;
-}
-
-int dm_lock_tdir(struct dentry *dentry)
-{
-	struct dentry de_list[4];
-	int n, rv;
-
-	rv = n = dm_child_list(de_list, dentry);
-	if (n) {
-		rv = deny_dentry_list(de_list, n);
-		dput_list(de_list, n);
-	}
-
-	return rv;
-}
-
-int dm_unlock_tdir(struct dentry *dentry)
-{
-	struct dentry de_list[4];
-
-	rv = dm_child_list(de_list, dentry);
-	if (rv) {
-		dm_allow_dentry_list(de_list, rv);
-		dput_list(de_list, rv);
-	}
-
-	return rv;
 }
 
 static int dmfs_tdir_unlink(struct inode *dir, struct dentry *dentry)