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Commit fa330659 authored by Omar Sandoval's avatar Omar Sandoval Committed by Chris Mason
Browse files

Btrfs: clean up error handling in mount_subvol() 



In preparation for new functionality in mount_subvol(), give it
ownership of subvol_name and tidy up the error paths.

Reviewed-by: default avatarDavid Sterba <dsterba@suse.cz>
Signed-off-by: default avatarOmar Sandoval <osandov@osandov.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent e6e4dbe8

fs/btrfs/super.c

+33 −28
Original line number Diff line number Diff line
@@ -1171,55 +1171,61 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, 
				   const char *device_name, char *data)

{

	struct dentry *root;

	struct vfsmount *mnt;

	struct vfsmount *mnt = NULL;

	char *newargs;

	int ret;



	newargs = setup_root_args(data);

	if (!newargs)

		return ERR_PTR(-ENOMEM);

	mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,

			     newargs);

	if (!newargs) {

		root = ERR_PTR(-ENOMEM);

		goto out;

	}



	if (PTR_RET(mnt) == -EBUSY) {

	mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);

	if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {

		if (flags & MS_RDONLY) {

			mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,

					     newargs);

			mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY,

					     device_name, newargs);

		} else {

			int r;

			mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,

					     newargs);

			mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY,

					     device_name, newargs);

			if (IS_ERR(mnt)) {

				kfree(newargs);

				return ERR_CAST(mnt);

				root = ERR_CAST(mnt);

				mnt = NULL;

				goto out;

			}



			down_write(&mnt->mnt_sb->s_umount);

			r = btrfs_remount(mnt->mnt_sb, &flags, NULL);

			ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);

			up_write(&mnt->mnt_sb->s_umount);

			if (r < 0) {

				/* FIXME: release vfsmount mnt ??*/

				kfree(newargs);

				return ERR_PTR(r);

			if (ret < 0) {

				root = ERR_PTR(ret);

				goto out;

			}

		}

	}



	kfree(newargs);



	if (IS_ERR(mnt))

		return ERR_CAST(mnt);

	if (IS_ERR(mnt)) {

		root = ERR_CAST(mnt);

		mnt = NULL;

		goto out;

	}



	root = mount_subtree(mnt, subvol_name);

	/* mount_subtree() drops our reference on the vfsmount. */

	mnt = NULL;



	if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) {

		struct super_block *s = root->d_sb;

		dput(root);

		root = ERR_PTR(-EINVAL);

		deactivate_locked_super(s);

		printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",

				subvol_name);

		pr_err("BTRFS: '%s' is not a valid subvolume\n", subvol_name);

	}



out:

	mntput(mnt);

	kfree(newargs);

	kfree(subvol_name);

	return root;

}
@@ -1305,9 +1311,8 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 
	}



	if (subvol_name) {

		root = mount_subvol(subvol_name, flags, device_name, data);

		kfree(subvol_name);

		return root;

		/* mount_subvol() will free subvol_name. */

		return mount_subvol(subvol_name, flags, device_name, data);

	}



	security_init_mnt_opts(&new_sec_opts);