Commit 15179cf2 authored by Steve French's avatar Steve French
Browse files

smb3: fix problem unloading module due to leaked refcount on shutdown 



The shutdown ioctl can leak a refcount on the tlink which can
prevent rmmod (unloading the cifs.ko) module from working.

Found while debugging xfstest generic/043

Fixes: 69ca1f57 ("smb3: add dynamic tracepoints for shutdown ioctl")
Reviewed-by: default avatarMeetakshi Setiya <msetiya@microsoft.com>
Reviewed-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent e4be320e

fs/smb/client/connect.c

+3 −0
Original line number Diff line number Diff line
@@ -4194,6 +4194,9 @@ tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink) 
 *

 * If one doesn't exist then insert a new tcon_link struct into the tree and

 * try to construct a new one.

 *

 * REMEMBER to call cifs_put_tlink() after successful calls to cifs_sb_tlink,

 * to avoid refcount issues

 */

struct tcon_link *

cifs_sb_tlink(struct cifs_sb_info *cifs_sb)

fs/smb/client/ioctl.c

+2 −0
Original line number Diff line number Diff line
@@ -229,9 +229,11 @@ static int cifs_shutdown(struct super_block *sb, unsigned long arg) 


shutdown_good:

	trace_smb3_shutdown_done(flags, tcon->tid);

	cifs_put_tlink(tlink);

	return 0;

shutdown_out_err:

	trace_smb3_shutdown_err(rc, flags, tcon->tid);

	cifs_put_tlink(tlink);

	return rc;

}

fs/smb/client/link.c

+1 −0
Original line number Diff line number Diff line
@@ -588,6 +588,7 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, 
	tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink)) {

		rc = PTR_ERR(tlink);

		/* BB could be clearer if skipped put_tlink on error here, but harmless */

		goto symlink_exit;

	}

	pTcon = tlink_tcon(tlink);