Commit dce2630c authored by NeilBrown's avatar NeilBrown Committed by Trond Myklebust
Browse files

NFSv4: always set NFS_LOCK_LOST when a lock is lost. 



There are 2 comments in the NFSv4 code which suggest that
SIGLOST should possibly be sent to a process.  In these
cases a lock has been lost.
The current practice is to set NFS_LOCK_LOST so that
read/write returns EIO when a lock is lost.
So change these comments to code when sets NFS_LOCK_LOST.

One case is when lock recovery after apparent server restart
fails with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, or
NFS4ERRO_RECLAIM_CONFLICT.  The other case is when a lock
attempt as part of lease recovery fails with NFS4ERR_DENIED.

In an ideal world, these should not happen.  However I have
a packet trace showing an NFSv4.1 session getting
NFS4ERR_BADSESSION after an extended network parition.  The
NFSv4.1 client treats this like server reboot until/unless
it get NFS4ERR_NO_GRACE, in which case it switches over to
"nograce" recovery mode.  In this network trace, the client
attempts to recover a lock and the server (incorrectly)
reports NFS4ERR_DENIED rather than NFS4ERR_NO_GRACE.  This
leads to the ineffective comment and the client then
continues to write using the OPEN stateid.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent aaa15008

fs/nfs/nfs4proc.c

+8 −4
Original line number Diff line number Diff line
@@ -2019,7 +2019,7 @@ static int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *sta 
	return ret;

}



static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct nfs4_state *state, const nfs4_stateid *stateid, int err)

static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct nfs4_state *state, const nfs4_stateid *stateid, struct file_lock *fl, int err)

{

	switch (err) {

		default:
@@ -2066,7 +2066,11 @@ static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct 
			return -EAGAIN;

		case -ENOMEM:

		case -NFS4ERR_DENIED:

			/* kill_proc(fl->fl_pid, SIGLOST, 1); */

			if (fl) {

				struct nfs4_lock_state *lsp = fl->fl_u.nfs4_fl.owner;

				if (lsp)

					set_bit(NFS_LOCK_LOST, &lsp->ls_flags);

			}

			return 0;

	}

	return err;
@@ -2102,7 +2106,7 @@ int nfs4_open_delegation_recall(struct nfs_open_context *ctx, 
		err = nfs4_open_recover_helper(opendata, FMODE_READ);

	}

	nfs4_opendata_put(opendata);

	return nfs4_handle_delegation_recall_error(server, state, stateid, err);

	return nfs4_handle_delegation_recall_error(server, state, stateid, NULL, err);

}



static void nfs4_open_confirm_prepare(struct rpc_task *task, void *calldata)
@@ -6757,7 +6761,7 @@ int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, 
	if (err != 0)

		return err;

	err = _nfs4_do_setlk(state, F_SETLK, fl, NFS_LOCK_NEW);

	return nfs4_handle_delegation_recall_error(server, state, stateid, err);

	return nfs4_handle_delegation_recall_error(server, state, stateid, fl, err);

}



struct nfs_release_lockowner_data {

fs/nfs/nfs4state.c

+4 −1
Original line number Diff line number Diff line
@@ -1482,6 +1482,7 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_ 
	struct inode *inode = state->inode;

	struct nfs_inode *nfsi = NFS_I(inode);

	struct file_lock *fl;

	struct nfs4_lock_state *lsp;

	int status = 0;

	struct file_lock_context *flctx = inode->i_flctx;

	struct list_head *list;
@@ -1522,7 +1523,9 @@ restart: 
		case -NFS4ERR_DENIED:

		case -NFS4ERR_RECLAIM_BAD:

		case -NFS4ERR_RECLAIM_CONFLICT:

			/* kill_proc(fl->fl_pid, SIGLOST, 1); */

			lsp = fl->fl_u.nfs4_fl.owner;

			if (lsp)

				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);

			status = 0;

		}

		spin_lock(&flctx->flc_lock);

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