ceph: fix ceph_lookup_open intent usage

We weren't properly calling lookup_instantiate_filp when setting up the
lookup intent, which could lead to file leakage on errors.  So:

 - use separate helper for the hidden snapdir translation, immediately
   following the mds request
 - use ceph_finish_lookup for the final dentry/return value dance in the
   exit path
 - lookup_instantiate_filp on success

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 53b441f..f39a409 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -482,18 +482,10 @@ static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int origin)
 }
 
 /*
- * Process result of a lookup/open request.
- *
- * Mainly, make sure we return the final req->r_dentry (if it already
- * existed) in place of the original VFS-provided dentry when they
- * differ.
- *
- * Gracefully handle the case where the MDS replies with -ENOENT and
- * no trace (which it may do, at its discretion, e.g., if it doesn't
- * care to issue a lease on the negative dentry).
+ * Handle lookups for the hidden .snap directory.
  */
-struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
-                                 struct dentry *dentry, int err)
+int ceph_handle_snapdir(struct ceph_mds_request *req,
+                       struct dentry *dentry, int err)
 {
        struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
        struct inode *parent = dentry->d_parent->d_inode;
@@ -510,7 +502,23 @@ struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
                d_add(dentry, inode);
                err = 0;
        }
+       return err;
+}
 
+/*
+ * Figure out final result of a lookup/open request.
+ *
+ * Mainly, make sure we return the final req->r_dentry (if it already
+ * existed) in place of the original VFS-provided dentry when they
+ * differ.
+ *
+ * Gracefully handle the case where the MDS replies with -ENOENT and
+ * no trace (which it may do, at its discretion, e.g., if it doesn't
+ * care to issue a lease on the negative dentry).
+ */
+struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
+                                 struct dentry *dentry, int err)
+{
        if (err == -ENOENT) {
                /* no trace? */
                err = 0;
@@ -605,6 +613,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
        req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
        req->r_locked_dir = dir;
        err = ceph_mdsc_do_request(mdsc, NULL, req);
+       err = ceph_handle_snapdir(req, dentry, err);
        dentry = ceph_finish_lookup(req, dentry, err);
        ceph_mdsc_put_request(req);  /* will dput(dentry) */
        dout("lookup result=%p\n", dentry);

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index e0115eb..f34d47d 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -223,8 +223,9 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 {
        struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
        struct ceph_mds_client *mdsc = fsc->mdsc;
-       struct file *file = nd->intent.open.file;
+       struct file *file;
        struct ceph_mds_request *req;
+       struct dentry *ret;
        int err;
        int flags = nd->intent.open.flags - 1;  /* silly vfs! */
 
@@ -245,15 +246,21 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
        err = ceph_mdsc_do_request(mdsc,
                                   (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
                                   req);
-       dentry = ceph_finish_lookup(req, dentry, err);
-       if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
+       err = ceph_handle_snapdir(req, dentry, err);
+       if (err)
+               goto out;
+       if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
                err = ceph_handle_notrace_create(dir, dentry);
-       if (!err)
-               err = ceph_init_file(req->r_dentry->d_inode, file,
-                                    req->r_fmode);
+       if (err)
+               goto out;
+       file = lookup_instantiate_filp(nd, req->r_dentry, ceph_open);
+       if (IS_ERR(file))
+               err = PTR_ERR(file);
+out:
+       ret = ceph_finish_lookup(req, dentry, err);
        ceph_mdsc_put_request(req);
-       dout("ceph_lookup_open result=%p\n", dentry);
-       return dentry;
+       dout("ceph_lookup_open result=%p\n", ret);
+       return ret;
 }
 
 int ceph_release(struct inode *inode, struct file *file)

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index a8a2733..c24891a 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -791,6 +791,8 @@ extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
        ceph_snapdir_dentry_ops;
 
 extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);
+extern int ceph_handle_snapdir(struct ceph_mds_request *req,
+                              struct dentry *dentry, int err);
 extern struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
                                         struct dentry *dentry, int err);