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

commit 62e2a47cea upstream.

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: bf0291dd22 ("pNFS: Ensure LAYOUTGET and LAYOUTRETURN are properly serialised")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Trond Myklebust 2024-12-16 19:28:06 -05:00 committed by Greg Kroah-Hartman
parent 4f95a2186b
commit 16846e8e0a

View File

@ -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;