nfsd: merge stable fix into main nfsd branch

7 files changed, 105 insertions, 39 deletions

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 8f6a2a5863b9..a27fc8791551 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -285,6 +285,7 @@ initiate_cifs_search(const unsigned int xid, struct file *file)
 			rc = -ENOMEM;
 			goto error_exit;
 		}
+		spin_lock_init(&cifsFile->file_info_lock);
 		file->private_data = cifsFile;
 		cifsFile->tlink = cifs_get_tlink(tlink);
 		tcon = tlink_tcon(tlink);
diff --git a/fs/dax.c b/fs/dax.c
index 3af2da5e64ce..c45598b912e1 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1031,6 +1031,11 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 		struct blk_dax_ctl dax = { 0 };
 		ssize_t map_len;
 
+		if (fatal_signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
 		dax.sector = dax_iomap_sector(iomap, pos);
 		dax.size = (length + offset + PAGE_SIZE - 1) & PAGE_MASK;
 		map_len = dax_map_atomic(iomap->bdev, &dax);
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 4304072161aa..40d61077bead 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -542,6 +542,7 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
 		hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) {
 			if (invalidate)
 				set_bit(FSCACHE_OBJECT_RETIRED, &object->flags);
+			clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
 			fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
 		}
 	} else {
@@ -560,6 +561,10 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
 		wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t,
 				 TASK_UNINTERRUPTIBLE);
 
+	/* Make sure any pending writes are cancelled. */
+	if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX)
+		fscache_invalidate_writes(cookie);
+
 	/* Reset the cookie state if it wasn't relinquished */
 	if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) {
 		atomic_inc(&cookie->n_active);
diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index 9b28649df3a1..a8aa00be4444 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -48,6 +48,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
 	cookie->flags		= 1 << FSCACHE_COOKIE_ENABLED;
 
 	spin_lock_init(&cookie->lock);
+	spin_lock_init(&cookie->stores_lock);
 	INIT_HLIST_HEAD(&cookie->backing_objects);
 
 	/* check the netfs type is not already present */
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 9e792e30f4db..7a182c87f378 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -30,6 +30,7 @@ static const struct fscache_state *fscache_look_up_object(struct fscache_object
 static const struct fscache_state *fscache_object_available(struct fscache_object *, int);
 static const struct fscache_state *fscache_parent_ready(struct fscache_object *, int);
 static const struct fscache_state *fscache_update_object(struct fscache_object *, int);
+static const struct fscache_state *fscache_object_dead(struct fscache_object *, int);
 
 #define __STATE_NAME(n) fscache_osm_##n
 #define STATE(n) (&__STATE_NAME(n))
@@ -91,7 +92,7 @@ static WORK_STATE(LOOKUP_FAILURE,	"LCFL", fscache_lookup_failure);
 static WORK_STATE(KILL_OBJECT,		"KILL", fscache_kill_object);
 static WORK_STATE(KILL_DEPENDENTS,	"KDEP", fscache_kill_dependents);
 static WORK_STATE(DROP_OBJECT,		"DROP", fscache_drop_object);
-static WORK_STATE(OBJECT_DEAD,		"DEAD", (void*)2UL);
+static WORK_STATE(OBJECT_DEAD,		"DEAD", fscache_object_dead);
 
 static WAIT_STATE(WAIT_FOR_INIT,	"?INI",
 		  TRANSIT_TO(INIT_OBJECT,	1 << FSCACHE_OBJECT_EV_NEW_CHILD));
@@ -229,6 +230,10 @@ execute_work_state:
 	event = -1;
 	if (new_state == NO_TRANSIT) {
 		_debug("{OBJ%x} %s notrans", object->debug_id, state->name);
+		if (unlikely(state == STATE(OBJECT_DEAD))) {
+			_leave(" [dead]");
+			return;
+		}
 		fscache_enqueue_object(object);
 		event_mask = object->oob_event_mask;
 		goto unmask_events;
@@ -239,7 +244,7 @@ execute_work_state:
 	object->state = state = new_state;
 
 	if (state->work) {
-		if (unlikely(state->work == ((void *)2UL))) {
+		if (unlikely(state == STATE(OBJECT_DEAD))) {
 			_leave(" [dead]");
 			return;
 		}
@@ -645,6 +650,12 @@ static const struct fscache_state *fscache_kill_object(struct fscache_object *ob
 	fscache_mark_object_dead(object);
 	object->oob_event_mask = 0;
 
+	if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) {
+		/* Reject any new read/write ops and abort any that are pending. */
+		clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
+		fscache_cancel_all_ops(object);
+	}
+
 	if (list_empty(&object->dependents) &&
 	    object->n_ops == 0 &&
 	    object->n_children == 0)
@@ -1077,3 +1088,20 @@ void fscache_object_mark_killed(struct fscache_object *object,
 	}
 }
 EXPORT_SYMBOL(fscache_object_mark_killed);
+
+/*
+ * The object is dead.  We can get here if an object gets queued by an event
+ * that would lead to its death (such as EV_KILL) when the dispatcher is
+ * already running (and so can be requeued) but hasn't yet cleared the event
+ * mask.
+ */
+static const struct fscache_state *fscache_object_dead(struct fscache_object *object,
+						       int event)
+{
+	if (!test_and_set_bit(FSCACHE_OBJECT_RUN_AFTER_DEAD,
+			      &object->flags))
+		return NO_TRANSIT;
+
+	WARN(true, "FS-Cache object redispatched after death");
+	return NO_TRANSIT;
+}
diff --git a/fs/iomap.c b/fs/iomap.c
index 354a123f170e..a51cb4c07d4d 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -114,6 +114,9 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 
 	BUG_ON(pos + len > iomap->offset + iomap->length);
 
+	if (fatal_signal_pending(current))
+		return -EINTR;
+
 	page = grab_cache_page_write_begin(inode->i_mapping, index, flags);
 	if (!page)
 		return -ENOMEM;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 5859f5826045..2c132162796e 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -332,6 +332,37 @@ nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
 	}
 }
 
+static __be32
+nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct iattr *iap)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+	int host_err;
+
+	if (iap->ia_size < inode->i_size) {
+		__be32 err;
+
+		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
+				NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
+		if (err)
+			return err;
+	}
+
+	host_err = get_write_access(inode);
+	if (host_err)
+		goto out_nfserrno;
+
+	host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
+	if (host_err)
+		goto out_put_write_access;
+	return 0;
+
+out_put_write_access:
+	put_write_access(inode);
+out_nfserrno:
+	return nfserrno(host_err);
+}
+
 /*
  * Set various file attributes.  After this call fhp needs an fh_put.
  */
@@ -346,6 +377,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 	__be32		err;
 	int		host_err;
 	bool		get_write_count;
+	int		size_change = 0;
 
 	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
 		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
@@ -358,11 +390,11 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 	/* Get inode */
 	err = fh_verify(rqstp, fhp, ftype, accmode);
 	if (err)
-		return err;
+		goto out;
 	if (get_write_count) {
 		host_err = fh_want_write(fhp);
 		if (host_err)
-			goto out_host_err;
+			return nfserrno(host_err);
 	}
 
 	dentry = fhp->fh_dentry;
@@ -373,59 +405,50 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 		iap->ia_valid &= ~ATTR_MODE;
 
 	if (!iap->ia_valid)
-		return 0;
+		goto out;
 
 	nfsd_sanitize_attrs(inode, iap);
 
-	if (check_guard && guardtime != inode->i_ctime.tv_sec)
-		return nfserr_notsync;
-
 	/*
 	 * The size case is special, it changes the file in addition to the
-	 * attributes, and file systems don't expect it to be mixed with
-	 * "random" attribute changes.  We thus split out the size change
-	 * into a separate call for vfs_truncate, and do the rest as a
-	 * a separate setattr call.
+	 * attributes.
 	 */
 	if (iap->ia_valid & ATTR_SIZE) {
-		struct path path = {
-			.mnt	= fhp->fh_export->ex_path.mnt,
-			.dentry	= dentry,
-		};
-		bool implicit_mtime = false;
+		err = nfsd_get_write_access(rqstp, fhp, iap);
+		if (err)
+			goto out;
+		size_change = 1;
 
 		/*
-		 * vfs_truncate implicity updates the mtime IFF the file size
-		 * actually changes.  Avoid the additional seattr call below if
-		 * the only other attribute that the client sends is the mtime.
+		 * RFC5661, Section 18.30.4:
+		 *   Changing the size of a file with SETATTR indirectly
+		 *   changes the time_modify and change attributes.
+		 *
+		 * (and similar for the older RFCs)
 		 */
-		if (iap->ia_size != i_size_read(inode) &&
-		    ((iap->ia_valid & ~(ATTR_SIZE | ATTR_MTIME)) == 0))
-			implicit_mtime = true;
-
-		host_err = vfs_truncate(&path, iap->ia_size);
-		if (host_err)
-			goto out_host_err;
-
-		iap->ia_valid &= ~ATTR_SIZE;
-		if (implicit_mtime)
-			iap->ia_valid &= ~ATTR_MTIME;
-		if (!iap->ia_valid)
-			goto done;
+		if (iap->ia_size != i_size_read(inode))
+			iap->ia_valid |= ATTR_MTIME;
 	}
 
 	iap->ia_valid |= ATTR_CTIME;
 
+	if (check_guard && guardtime != inode->i_ctime.tv_sec) {
+		err = nfserr_notsync;
+		goto out_put_write_access;
+	}
+
 	fh_lock(fhp);
 	host_err = notify_change(dentry, iap, NULL);
 	fh_unlock(fhp);
-	if (host_err)
-		goto out_host_err;
+	err = nfserrno(host_err);
 
-done:
-	host_err = commit_metadata(fhp);
-out_host_err:
-	return nfserrno(host_err);
+out_put_write_access:
+	if (size_change)
+		put_write_access(inode);
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+out:
+	return err;
 }
 
 #if defined(CONFIG_NFSD_V4)