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Commit a01b3007 authored by Al Viro's avatar Al Viro
Browse files

configfs_readdir(): make safe under shared lock 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 884be175

fs/configfs/dir.c

+7 −13
Original line number Diff line number Diff line
@@ -1633,11 +1633,9 @@ static int configfs_readdir(struct file *file, struct dir_context *ctx) 


	if (!dir_emit_dots(file, ctx))

		return 0;

	if (ctx->pos == 2) {

	spin_lock(&configfs_dirent_lock);

	if (ctx->pos == 2)

		list_move(q, &parent_sd->s_children);

		spin_unlock(&configfs_dirent_lock);

	}

	for (p = q->next; p != &parent_sd->s_children; p = p->next) {

		struct configfs_dirent *next;

		const char *name;
@@ -1648,9 +1646,6 @@ static int configfs_readdir(struct file *file, struct dir_context *ctx) 
		if (!next->s_element)

			continue;



		name = configfs_get_name(next);

		len = strlen(name);



		/*

		 * We'll have a dentry and an inode for

		 * PINNED items and for open attribute
@@ -1664,7 +1659,6 @@ static int configfs_readdir(struct file *file, struct dir_context *ctx) 
		 * they close it.  Beyond that, we don't

		 * care.

		 */

		spin_lock(&configfs_dirent_lock);

		dentry = next->s_dentry;

		if (dentry)

			inode = d_inode(dentry);
@@ -1674,15 +1668,18 @@ static int configfs_readdir(struct file *file, struct dir_context *ctx) 
		if (!inode)

			ino = iunique(sb, 2);



		name = configfs_get_name(next);

		len = strlen(name);



		if (!dir_emit(ctx, name, len, ino, dt_type(next)))

			return 0;



		spin_lock(&configfs_dirent_lock);

		list_move(q, p);

		spin_unlock(&configfs_dirent_lock);

		p = q;

		ctx->pos++;

	}

	spin_unlock(&configfs_dirent_lock);

	return 0;

}
@@ -1690,7 +1687,6 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) 
{

	struct dentry * dentry = file->f_path.dentry;



	inode_lock(d_inode(dentry));

	switch (whence) {

		case 1:

			offset += file->f_pos;
@@ -1698,7 +1694,6 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) 
			if (offset >= 0)

				break;

		default:

			inode_unlock(d_inode(dentry));

			return -EINVAL;

	}

	if (offset != file->f_pos) {
@@ -1724,7 +1719,6 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) 
			spin_unlock(&configfs_dirent_lock);

		}

	}

	inode_unlock(d_inode(dentry));

	return offset;

}
@@ -1733,7 +1727,7 @@ const struct file_operations configfs_dir_operations = { 
	.release	= configfs_dir_close,

	.llseek		= configfs_dir_lseek,

	.read		= generic_read_dir,

	.iterate	= configfs_readdir,

	.iterate_shared	= configfs_readdir,

};



/**