Commit ea0ded74 authored by Fred Isaman's avatar Fred Isaman Committed by Trond Myklebust
Browse files

nfs4.1: prevent race that allowed use of freed layout in _pnfs_return_layout 



mark_matching_lsegs_invalid could put the last ref to the layout, so
the get_layout_hdr needs to be called first.

Signed-off-by: default avatarFred Isaman <iisaman@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 1ed3a853

fs/nfs/pnfs.c

+2 −2
Original line number Diff line number Diff line
@@ -640,10 +640,10 @@ _pnfs_return_layout(struct inode *ino) 
		return status;

	}

	stateid = nfsi->layout->plh_stateid;

	mark_matching_lsegs_invalid(lo, &tmp_list, NULL);

	lo->plh_block_lgets++;

	/* Reference matched in nfs4_layoutreturn_release */

	get_layout_hdr(lo);

	mark_matching_lsegs_invalid(lo, &tmp_list, NULL);

	lo->plh_block_lgets++;

	spin_unlock(&ino->i_lock);

	pnfs_free_lseg_list(&tmp_list);