From a4f4d6df537368297a84e6b9444f403f99bf59f6 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 8 Dec 2008 18:24:18 -0500 Subject: [PATCH] EXPORTFS: handle NULL returns from fh_to_dentry()/fh_to_parent() While 440037287c5 "[PATCH] switch all filesystems over to d_obtain_alias" removed some cases where fh_to_dentry() and fh_to_parent() could return NULL, there are still a few NULL returns left in individual filesystems. Thus it was a mistake for that commit to remove the handling of NULL returns in the callers. Revert those parts of 440037287c5 which removed the NULL handling. (We could, alternatively, modify all implementations to return -ESTALE instead of NULL, but that proves to require fixing a number of filesystems, and in some cases it's arguably more natural to return NULL.) Thanks to David for original patch and Linus, Christoph, and Hugh for review. Signed-off-by: J. Bruce Fields Cc: David Howells Cc: Christoph Hellwig Cc: Hugh Dickins Signed-off-by: Linus Torvalds --- fs/exportfs/expfs.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 80246ba..890e018 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -367,6 +367,8 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid, * Try to get any dentry for the given file handle from the filesystem. */ result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type); + if (!result) + result = ERR_PTR(-ESTALE); if (IS_ERR(result)) return result; @@ -420,6 +422,8 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid, target_dir = nop->fh_to_parent(mnt->mnt_sb, fid, fh_len, fileid_type); + if (!target_dir) + goto err_result; err = PTR_ERR(target_dir); if (IS_ERR(target_dir)) goto err_result; -- 1.8.2.3