bug fix: don't warn if trying to mntput a "negative" union object

In unionfs_d_release, we may get negative dentries which don't have a lower
mnt.  In that case, don't print a warning message from unionfs_mntput about
trying to put a NULL mnt.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c
index 1653267c1d5a5fa94861e633237f1954bcfecae8..c9ff88676db211d7daaf2819349400a67b020a20 100644 (file)
--- a/fs/unionfs/dentry.c
+++ b/fs/unionfs/dentry.c
@@ -325,9 +325,11 @@ static void unionfs_d_release(struct dentry *dentry)
        bend = dbend(dentry);
        for (bindex = bstart; bindex <= bend; bindex++) {
                dput(unionfs_lower_dentry_idx(dentry, bindex));
-               unionfs_mntput(dentry, bindex);
-
                unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
+               /* NULL lower mnt is ok if this is a negative dentry */
+               if (!dentry->d_inode && !unionfs_lower_mnt_idx(dentry,bindex))
+                       continue;
+               unionfs_mntput(dentry, bindex);
                unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
        }
        /* free private data (unionfs_dentry_info) here */