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Commit 13aab428 authored by Al Viro's avatar Al Viro
Browse files

separate -ESTALE/-ECHILD retries in do_filp_open() from real work 



new helper: path_openat().  Does what do_filp_open() does, except
that it tries only the walk mode (RCU/normal/force revalidation)
it had been told to.

Both create and non-create branches are using path_lookupat() now.
Fixed the double audit_inode() in non-create branch.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 47c805dc

fs/namei.c

+20 −29
Original line number Diff line number Diff line
@@ -2292,19 +2292,14 @@ static struct file *do_last(struct nameidata *nd, struct path *path, 
	return ERR_PTR(error);

}



/*

 * Note that the low bits of the passed in "open_flag"

 * are not the same as in the local variable "flag". See

 * open_to_namei_flags() for more details.

 */

struct file *do_filp_open(int dfd, const char *pathname,

static struct file *path_openat(int dfd, const char *pathname,

		const struct open_flags *op, int flags)

{

	struct file *filp;

	struct nameidata nd;

	int error;

	struct path path;

	int count = 0;

	int error;



	filp = get_empty_filp();

	if (!filp)
@@ -2319,42 +2314,27 @@ struct file *do_filp_open(int dfd, const char *pathname, 
		goto creat;



	/* !O_CREAT, simple open */

	error = do_path_lookup(dfd, pathname, flags | op->intent, &nd);

	error = path_lookupat(dfd, pathname, flags | op->intent, &nd);

	if (unlikely(error))

		goto out_filp2;

		goto out_filp;

	error = -ELOOP;

	if (!(nd.flags & LOOKUP_FOLLOW)) {

		if (nd.inode->i_op->follow_link)

			goto out_path2;

			goto out_path;

	}

	error = -ENOTDIR;

	if (nd.flags & LOOKUP_DIRECTORY) {

		if (!nd.inode->i_op->lookup)

			goto out_path2;

			goto out_path;

	}

	audit_inode(pathname, nd.path.dentry);

	filp = finish_open(&nd, op->open_flag, op->acc_mode);

out2:

	release_open_intent(&nd);

	return filp;



out_path2:

	path_put(&nd.path);

out_filp2:

	filp = ERR_PTR(error);

	goto out2;



creat:

	/* OK, have to create the file. Find the parent. */

	error = path_lookupat(dfd, pathname,

			LOOKUP_PARENT | LOOKUP_RCU | flags, &nd);

	if (unlikely(error == -ECHILD))

		error = path_lookupat(dfd, pathname, LOOKUP_PARENT | flags, &nd);

	if (unlikely(error == -ESTALE)) {

reval:

		flags |= LOOKUP_REVAL;

	error = path_lookupat(dfd, pathname, LOOKUP_PARENT | flags, &nd);

	}

	if (unlikely(error))

		goto out_filp;

	if (unlikely(!audit_dummy_context()))
@@ -2398,8 +2378,6 @@ struct file *do_filp_open(int dfd, const char *pathname, 
out:

	if (nd.root.mnt)

		path_put(&nd.root);

	if (filp == ERR_PTR(-ESTALE) && !(flags & LOOKUP_REVAL))

		goto reval;

	release_open_intent(&nd);

	return filp;
@@ -2412,6 +2390,19 @@ struct file *do_filp_open(int dfd, const char *pathname, 
	goto out;

}



struct file *do_filp_open(int dfd, const char *pathname,

		const struct open_flags *op, int flags)

{

	struct file *filp;



	filp = path_openat(dfd, pathname, op, flags | LOOKUP_RCU);

	if (unlikely(filp == ERR_PTR(-ECHILD)))

		filp = path_openat(dfd, pathname, op, flags);

	if (unlikely(filp == ERR_PTR(-ESTALE)))

		filp = path_openat(dfd, pathname, op, flags | LOOKUP_REVAL);

	return filp;

}



/**

 * lookup_create - lookup a dentry, creating it if it doesn't exist

 * @nd: nameidata info