Commit 9da6ec77 authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: use a refcount to protect open/closing the cached file handle 



Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Cc: <stable@vger.kernel.org>
parent bf1fdeb7

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -907,6 +907,7 @@ cap_unix(struct cifs_ses *ses) 


struct cached_fid {

	bool is_valid:1;	/* Do we have a useable root fid */

	struct kref refcount;

	struct cifs_fid *fid;

	struct mutex fid_mutex;

	struct cifs_tcon *tcon;

fs/cifs/smb2inode.c

+3 −1
Original line number Diff line number Diff line
@@ -120,7 +120,9 @@ smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon, 
		break;

	}



	if (use_cached_root_handle == false)

	if (use_cached_root_handle)

		close_shroot(&tcon->crfid);

	else

		rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);

	if (tmprc)

		rc = tmprc;

fs/cifs/smb2ops.c

+26 −5
Original line number Diff line number Diff line
@@ -470,21 +470,36 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon) 
	return rc;

}



void

smb2_cached_lease_break(struct work_struct *work)

static void

smb2_close_cached_fid(struct kref *ref)

{

	struct cached_fid *cfid = container_of(work,

				struct cached_fid, lease_break);

	mutex_lock(&cfid->fid_mutex);

	struct cached_fid *cfid = container_of(ref, struct cached_fid,

					       refcount);



	if (cfid->is_valid) {

		cifs_dbg(FYI, "clear cached root file handle\n");

		SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,

			   cfid->fid->volatile_fid);

		cfid->is_valid = false;

	}

}



void close_shroot(struct cached_fid *cfid)

{

	mutex_lock(&cfid->fid_mutex);

	kref_put(&cfid->refcount, smb2_close_cached_fid);

	mutex_unlock(&cfid->fid_mutex);

}



void

smb2_cached_lease_break(struct work_struct *work)

{

	struct cached_fid *cfid = container_of(work,

				struct cached_fid, lease_break);



	close_shroot(cfid);

}



/*

 * Open the directory at the root of a share

 */
@@ -499,6 +514,7 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) 
	if (tcon->crfid.is_valid) {

		cifs_dbg(FYI, "found a cached root file handle\n");

		memcpy(pfid, tcon->crfid.fid, sizeof(struct cifs_fid));

		kref_get(&tcon->crfid.refcount);

		mutex_unlock(&tcon->crfid.fid_mutex);

		return 0;

	}
@@ -515,6 +531,8 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) 
		memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));

		tcon->crfid.tcon = tcon;

		tcon->crfid.is_valid = true;

		kref_init(&tcon->crfid.refcount);

		kref_get(&tcon->crfid.refcount);

	}

	mutex_unlock(&tcon->crfid.fid_mutex);

	return rc;
@@ -558,6 +576,9 @@ smb3_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon) 
			FS_SECTOR_SIZE_INFORMATION); /* SMB3 specific */

	if (no_cached_open)

		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);

	else

		close_shroot(&tcon->crfid);



	return;

}

fs/cifs/smb2proto.h

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ extern int smb3_handle_read_data(struct TCP_Server_Info *server, 


extern int open_shroot(unsigned int xid, struct cifs_tcon *tcon,

			struct cifs_fid *pfid);

extern void close_shroot(struct cached_fid *cfid);

extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst,

				   struct smb2_file_all_info *src);

extern int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,