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Commit 59c55ba1 authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: don't take extra tlink reference in initiate_cifs_search 

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: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 987b21d7

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) {