Commit e75b23f9 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd: check d_can_lookup in fh_verify of directories 



Create and other nfsd ops generally assume we can call lookup_one_len on
inodes with S_IFDIR set.  Al says that this assumption isn't true in
general, though it should be for the filesystem objects nfsd sees.

Add a check just to make sure our assumption isn't violated.

Remove a couple checks for i_op->lookup in create code.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 12391d07

fs/nfsd/nfsfh.c

+10 −4
Original line number Diff line number Diff line
@@ -59,14 +59,20 @@ static int nfsd_acceptable(void *expv, struct dentry *dentry) 
 * the write call).

 */

static inline __be32

nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)

nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,

		umode_t requested)

{

	mode &= S_IFMT;

	umode_t mode = d_inode(dentry)->i_mode & S_IFMT;



	if (requested == 0) /* the caller doesn't care */

		return nfs_ok;

	if (mode == requested)

	if (mode == requested) {

		if (mode == S_IFDIR && !d_can_lookup(dentry)) {

			WARN_ON_ONCE(1);

			return nfserr_notdir;

		}

		return nfs_ok;

	}

	/*

	 * v4 has an error more specific than err_notdir which we should

	 * return in preference to err_notdir:
@@ -340,7 +346,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access) 
	if (error)

		goto out;



	error = nfsd_mode_check(rqstp, d_inode(dentry)->i_mode, type);

	error = nfsd_mode_check(rqstp, dentry, type);

	if (error)

		goto out;

fs/nfsd/vfs.c

+0 −9
Original line number Diff line number Diff line
@@ -1169,9 +1169,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	dentry = fhp->fh_dentry;

	dirp = d_inode(dentry);



	err = nfserr_notdir;

	if (!dirp->i_op->lookup)

		goto out;

	/*

	 * Check whether the response file handle has been verified yet.

	 * If it has, the parent directory should already be locked.
@@ -1310,12 +1307,6 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	dentry = fhp->fh_dentry;

	dirp = d_inode(dentry);



	/* Get all the sanity checks out of the way before

	 * we lock the parent. */

	err = nfserr_notdir;

	if (!dirp->i_op->lookup)

		goto out;



	host_err = fh_want_write(fhp);

	if (host_err)

		goto out_nfserr;

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