Commit a4f4d6df authored Dec 08, 2008 by J. Bruce Fields Committed by Linus Torvalds Dec 08, 2008

EXPORTFS: handle NULL returns from fh_to_dentry()/fh_to_parent()



While 44003728 "[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 44003728 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 <bfields@citi.umich.edu>
Cc: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 218d11a8

fs/exportfs/expfs.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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;

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