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Commit 19e03c57 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Ensure that file unlock requests don't conflict with state recovery 



The unlock path is currently failing to take the nfs_client->cl_sem read
lock, and hence the recovery path may see locks disappear from underneath
it.
Also ensure that it takes the nfs_inode->rwsem read lock so that it there
is no conflict with delegation recalls.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 65de872e

fs/nfs/nfs4proc.c

+16 −10
Original line number Original line Diff line number Diff line
@@ -3273,6 +3273,8 @@ static struct rpc_task *nfs4_do_unlck(struct file_lock *fl, 




static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)

static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)

{

{

	struct nfs_client *clp = state->owner->so_client;

	struct nfs_inode *nfsi = NFS_I(state->inode);

	struct nfs_seqid *seqid;

	struct nfs_seqid *seqid;

	struct nfs4_lock_state *lsp;

	struct nfs4_lock_state *lsp;

	struct rpc_task *task;

	struct rpc_task *task;
@@ -3282,8 +3284,15 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock * 
	status = nfs4_set_lock_state(state, request);

	status = nfs4_set_lock_state(state, request);

	/* Unlock _before_ we do the RPC call */

	/* Unlock _before_ we do the RPC call */

	request->fl_flags |= FL_EXISTS;

	request->fl_flags |= FL_EXISTS;

	if (do_vfs_lock(request->fl_file, request) == -ENOENT)

	down_read(&clp->cl_sem);

	down_read(&nfsi->rwsem);

	if (do_vfs_lock(request->fl_file, request) == -ENOENT) {

		up_read(&nfsi->rwsem);

		up_read(&clp->cl_sem);

		goto out;

		goto out;

	}

	up_read(&nfsi->rwsem);

	up_read(&clp->cl_sem);

	if (status != 0)

	if (status != 0)

		goto out;

		goto out;

	/* Is this a delegated lock? */

	/* Is this a delegated lock? */
@@ -3510,6 +3519,7 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request 
static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)

static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)

{

{

	struct nfs_client *clp = state->owner->so_client;

	struct nfs_client *clp = state->owner->so_client;

	struct nfs_inode *nfsi = NFS_I(state->inode);

	unsigned char fl_flags = request->fl_flags;

	unsigned char fl_flags = request->fl_flags;

	int status;

	int status;
@@ -3522,19 +3532,14 @@ static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock 
	if (status < 0)

	if (status < 0)

		goto out;

		goto out;

	down_read(&clp->cl_sem);

	down_read(&clp->cl_sem);

	down_read(&nfsi->rwsem);

	if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {

	if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {

		struct nfs_inode *nfsi = NFS_I(state->inode);

		/* Yes: cache locks! */

		/* Yes: cache locks! */

		down_read(&nfsi->rwsem);

		/* ...but avoid races with delegation recall... */

		/* ...but avoid races with delegation recall... */

		if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {

		request->fl_flags = fl_flags & ~FL_SLEEP;

		request->fl_flags = fl_flags & ~FL_SLEEP;

		status = do_vfs_lock(request->fl_file, request);

		status = do_vfs_lock(request->fl_file, request);

			up_read(&nfsi->rwsem);

		goto out_unlock;

		goto out_unlock;

	}

	}

		up_read(&nfsi->rwsem);

	}

	status = _nfs4_do_setlk(state, cmd, request, 0);

	status = _nfs4_do_setlk(state, cmd, request, 0);

	if (status != 0)

	if (status != 0)

		goto out_unlock;

		goto out_unlock;
@@ -3543,6 +3548,7 @@ static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock 
	if (do_vfs_lock(request->fl_file, request) < 0)

	if (do_vfs_lock(request->fl_file, request) < 0)

		printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);

		printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);

out_unlock:

out_unlock:

	up_read(&nfsi->rwsem);

	up_read(&clp->cl_sem);

	up_read(&clp->cl_sem);

out:

out:

	request->fl_flags = fl_flags;

	request->fl_flags = fl_flags;

fs/nfs/nfs4state.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -849,9 +849,11 @@ static int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_s 
static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)

static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)

{

{

	struct inode *inode = state->inode;

	struct inode *inode = state->inode;

	struct nfs_inode *nfsi = NFS_I(inode);

	struct file_lock *fl;

	struct file_lock *fl;

	int status = 0;

	int status = 0;





	down_write(&nfsi->rwsem);

	for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {

	for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {

		if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))

		if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))

			continue;

			continue;
@@ -874,8 +876,10 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_ 
				goto out_err;

				goto out_err;

		}

		}

	}

	}

	up_write(&nfsi->rwsem);

	return 0;

	return 0;

out_err:

out_err:

	up_write(&nfsi->rwsem);

	return status;

	return status;

}

}