Commit 62e2a47c authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS/pnfs: Fix a live lock between recalled layouts and layoutget 



When the server is recalling a layout, we should ignore the count of
outstanding layoutget calls, since the server is expected to return
either NFS4ERR_RECALLCONFLICT or NFS4ERR_RETURNCONFLICT for as long as
the recall is outstanding.
Currently, we may end up livelocking, causing the layout to eventually
be forcibly revoked.

Fixes: bf0291dd ("pNFS: Ensure LAYOUTGET and LAYOUTRETURN are properly serialised")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 78d4f34e

fs/nfs/pnfs.c

+1 −1
Original line number Diff line number Diff line
@@ -1308,7 +1308,7 @@ pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo, 
		enum pnfs_iomode *iomode)

{

	/* Serialise LAYOUTGET/LAYOUTRETURN */

	if (atomic_read(&lo->plh_outstanding) != 0)

	if (atomic_read(&lo->plh_outstanding) != 0 && lo->plh_return_seq == 0)

		return false;

	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))

		return false;