Commit 8795e7d4 authored by Al Viro's avatar Al Viro
Browse files

do_last(): simplify the liveness analysis past finish_open_created 



Don't mess with got_write there - it is guaranteed to be false on
entry and it will be set true if and only if we decide to go for
truncation and manage to get write access for that.

Don't carry acc_mode through the entire thing - it's only used
in that part.  And don't bother with gotos in there - compiler is
quite capable of optimizing that.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 5a2d3edd

fs/namei.c

+11 −17
Original line number Diff line number Diff line
@@ -3122,9 +3122,9 @@ static const char *do_last(struct nameidata *nd, 
	kuid_t dir_uid = nd->inode->i_uid;

	umode_t dir_mode = nd->inode->i_mode;

	int open_flag = op->open_flag;

	bool will_truncate = (open_flag & O_TRUNC) != 0;

	bool do_truncate;

	bool got_write = false;

	int acc_mode = op->acc_mode;

	int acc_mode;

	unsigned seq;

	struct inode *inode;

	struct dentry *dentry;
@@ -3243,36 +3243,30 @@ finish_open: 
		return ERR_PTR(-ENOTDIR);



finish_open_created:

	do_truncate = false;

	acc_mode = op->acc_mode;

	if (file->f_mode & FMODE_CREATED) {

		/* Don't check for write permission, don't truncate */

		open_flag &= ~O_TRUNC;

		will_truncate = false;

		acc_mode = 0;

	} else if (!d_is_reg(nd->path.dentry)) {

		will_truncate = false;

	}

	if (will_truncate) {

	} else if (d_is_reg(nd->path.dentry) && open_flag & O_TRUNC) {

		error = mnt_want_write(nd->path.mnt);

		if (error)

			return ERR_PTR(error);

		got_write = true;

		do_truncate = true;

	}

	error = may_open(&nd->path, acc_mode, open_flag);

	if (error)

		goto out;

	if (!(file->f_mode & FMODE_OPENED))

	if (!error && !(file->f_mode & FMODE_OPENED))

		error = vfs_open(&nd->path, file);

	if (error)

		goto out;

	if (!error)

		error = ima_file_check(file, op->acc_mode);

	if (!error && will_truncate)

	if (!error && do_truncate)

		error = handle_truncate(file);

out:

	if (unlikely(error > 0)) {

		WARN_ON(1);

		error = -EINVAL;

	}

	if (got_write)

	if (do_truncate)

		mnt_drop_write(nd->path.mnt);

	return ERR_PTR(error);

}

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