NFS: Be strict about dentry revalidation when doing exclusive create (a12802ca) · Commits · e / devices / android_kernel_sony_msm8994

fs/nfs/dir.c

+14 −15

Original line number	Diff line number	Diff line
		@@ -668,6 +668,19 @@ static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigne
		return nd->flags & mask;
		}

		/*
		* Use intent information to check whether or not we're going to do
		* an O_EXCL create using this path component.
		*/
		static int nfs_is_exclusive_create(struct inode dir, struct nameidata nd)
		{
		if (NFS_PROTO(dir)->version == 2)
		return 0;
		if (nd == NULL \|\| nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
		return 0;
		return (nd->intent.open.flags & O_EXCL) != 0;
		}

		/*
		* Inode and filehandle revalidation for lookups.
		*
		@@ -754,7 +767,7 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
		}

		/* Force a full look up iff the parent directory has changed */
		if (nfs_check_verifier(dir, dentry)) {
		if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
		if (nfs_lookup_verify_inode(inode, nd))
		goto out_zap_parent;
		goto out_valid;
		@@ -848,20 +861,6 @@ struct dentry_operations nfs_dentry_operations = {
		.d_iput = nfs_dentry_iput,
		};

		/*
		* Use intent information to check whether or not we're going to do
		* an O_EXCL create using this path component.
		*/
		static inline
		int nfs_is_exclusive_create(struct inode dir, struct nameidata nd)
		{
		if (NFS_PROTO(dir)->version == 2)
		return 0;
		if (nd == NULL \|\| nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
		return 0;
		return (nd->intent.open.flags & O_EXCL) != 0;
		}

		static struct dentry nfs_lookup(struct inode dir, struct dentry * dentry, struct nameidata *nd)
		{
		struct dentry *res;