Unionfs: extend dentry branch configuration lock in open

Dentry branch configuration "info node" lock should extend to calls to
copy_attr_times.

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

diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index 8eb4e8434000aa1cfbf501cdc962fdcaa0ccc670..68023164de7a21a2301b47c712deb742f2933f32 100644 (file)
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -603,11 +603,22 @@ int unionfs_open(struct inode *inode, struct file *file)
 {
        int err = 0;
        struct file *lower_file = NULL;
-       struct dentry *dentry = NULL;
+       struct dentry *dentry = file->f_path.dentry;
        int bindex = 0, bstart = 0, bend = 0;
        int size;
 
        unionfs_read_lock(inode->i_sb, UNIONFS_SMUTEX_PARENT);
+       unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
+
+       /*
+        * With nfs exporting we cannot get a disconnected dentry here,
+        * since we already connect it in unionfs_get_parent.  This check
+        * can probably be removed after sufficient testing.
+        */
+       if (dentry->d_flags & DCACHE_DISCONNECTED) {
+               err = -ESTALE;
+               goto out;
+       }
 
        file->private_data =
                kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL);
@@ -633,18 +644,6 @@ int unionfs_open(struct inode *inode, struct file *file)
                goto out;
        }
 
-       dentry = file->f_path.dentry;
-
-       /*
-        * With nfs exporting we cannot get a disconnected dentry here,
-        * since we already connect it in unionfs_get_parent.  This check
-        * can probably be removed after sufficient testing.
-        */
-       if (dentry->d_flags & DCACHE_DISCONNECTED) {
-               err = -ESTALE;
-               goto out;
-       }
-       unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
 
        bstart = fbstart(file) = dbstart(dentry);
        bend = fbend(file) = dbend(dentry);
@@ -665,15 +664,12 @@ int unionfs_open(struct inode *inode, struct file *file)
                        if (!lower_file)
                                continue;
 
-                       branchput(file->f_path.dentry->d_sb, bindex);
+                       branchput(dentry->d_sb, bindex);
                        /* fput calls dput for lower_dentry */
                        fput(lower_file);
                }
        }
 
-       /* XXX: should this unlock be moved to the function bottom? */
-       unionfs_unlock_dentry(dentry);
-
 out:
        if (err) {
                kfree(UNIONFS_F(file)->lower_files);
@@ -682,12 +678,11 @@ out:
        }
 out_nofree:
        if (!err) {
-               dentry = file->f_path.dentry;
-               unionfs_copy_attr_times(dentry->d_parent->d_inode);
                unionfs_copy_attr_times(inode);
                unionfs_check_file(file);
                unionfs_check_inode(inode);
        }
+       unionfs_unlock_dentry(dentry);
        unionfs_read_unlock(inode->i_sb);
        return err;
 }