cifs: don't take extra tlink reference in initiate_cifs_search (59c55ba1) · Commits · 戴 / test

It's possible for initiate_cifs_search to be called on a filp that already has private_data attached. If this happens, we'll end up calling cifs_sb_tlink, taking an extra reference to the tlink and attaching that to the cifsFileInfo. This leads to refcount leaks that manifest as a "stuck" cifsd at umount time. Fix this by only looking up the tlink for the cifsFile on the filp's first pass through this function. When called on a filp that already has cifsFileInfo associated with it, just use the tlink reference that it already owns. This patch fixes samba.org bug 7792: https://bugzilla.samba.org/show_bug.cgi?id=7792 Signed-off-by:

Jeff Layton <jlayton@redhat.com> Reviewed-and-Tested-by:

Suresh Jayaraman <sjayaraman@suse.de> Signed-off-by:

Steve French <sfrench@us.ibm.com>

fs/cifs/readdir.c

+16 −13

Original line number	Diff line number	Diff line
		@@ -226,26 +226,29 @@ static int initiate_cifs_search(const int xid, struct file *file)
		char *full_path = NULL;
		struct cifsFileInfo *cifsFile;
		struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
		struct tcon_link *tlink;
		struct tcon_link *tlink = NULL;
		struct cifsTconInfo *pTcon;

		if (file->private_data == NULL) {
		tlink = cifs_sb_tlink(cifs_sb);
		if (IS_ERR(tlink))
		return PTR_ERR(tlink);
		pTcon = tlink_tcon(tlink);

		if (file->private_data == NULL)
		file->private_data =
		kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
		if (file->private_data == NULL) {
		cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
		if (cifsFile == NULL) {
		rc = -ENOMEM;
		goto error_exit;
		}

		file->private_data = cifsFile;
		cifsFile->tlink = cifs_get_tlink(tlink);
		pTcon = tlink_tcon(tlink);
		} else {
		cifsFile = file->private_data;
		pTcon = tlink_tcon(cifsFile->tlink);
		}

		cifsFile->invalidHandle = true;
		cifsFile->srch_inf.endOfSearch = false;
		cifsFile->tlink = cifs_get_tlink(tlink);

		full_path = build_path_from_dentry(file->f_path.dentry);
		if (full_path == NULL) {

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