1 files changed, 972 insertions, 0 deletions

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
new file mode 100644
index 000000000..5921dd368
--- /dev/null
+++ b/fs/afs/inode.c
@@ -0,0 +1,972 @@
+/*
+ * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
+ *
+ * This software may be freely redistributed under the terms of the
+ * GNU General Public License.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Authors: David Woodhouse <dwmw2@infradead.org>
+ *          David Howells <dhowells@redhat.com>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/iversion.h>
+#include "internal.h"
+#include "afs_fs.h"
+
+static const struct inode_operations afs_symlink_inode_operations = {
+	.get_link	= page_get_link,
+};
+
+static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
+{
+	static unsigned long once_only;
+
+	pr_warn("kAFS: AFS vnode with undefined type %u\n", vnode->status.type);
+	pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
+		vnode->status.abort_code,
+		vnode->status.mode,
+		vnode->status.size,
+		vnode->status.data_version);
+	pr_warn("kAFS: vnode %llx:%llx:%x\n",
+		vnode->fid.vid,
+		vnode->fid.vnode,
+		vnode->fid.unique);
+	if (parent_vnode)
+		pr_warn("kAFS: dir %llx:%llx:%x\n",
+			parent_vnode->fid.vid,
+			parent_vnode->fid.vnode,
+			parent_vnode->fid.unique);
+
+	if (!test_and_set_bit(0, &once_only))
+		dump_stack();
+}
+
+/*
+ * Set parameters for the netfs library
+ */
+static void afs_set_netfs_context(struct afs_vnode *vnode)
+{
+	netfs_inode_init(&vnode->netfs, &afs_req_ops);
+}
+
+/*
+ * Initialise an inode from the vnode status.
+ */
+static int afs_inode_init_from_status(struct afs_operation *op,
+				      struct afs_vnode_param *vp,
+				      struct afs_vnode *vnode)
+{
+	struct afs_file_status *status = &vp->scb.status;
+	struct inode *inode = AFS_VNODE_TO_I(vnode);
+	struct timespec64 t;
+
+	_enter("{%llx:%llu.%u} %s",
+	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
+	       op->type ? op->type->name : "???");
+
+	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
+	       status->type,
+	       status->nlink,
+	       (unsigned long long) status->size,
+	       status->data_version,
+	       status->mode);
+
+	write_seqlock(&vnode->cb_lock);
+
+	vnode->cb_v_break = op->cb_v_break;
+	vnode->cb_s_break = op->cb_s_break;
+	vnode->status = *status;
+
+	t = status->mtime_client;
+	inode->i_ctime = t;
+	inode->i_mtime = t;
+	inode->i_atime = t;
+	inode->i_flags |= S_NOATIME;
+	inode->i_uid = make_kuid(&init_user_ns, status->owner);
+	inode->i_gid = make_kgid(&init_user_ns, status->group);
+	set_nlink(&vnode->netfs.inode, status->nlink);
+
+	switch (status->type) {
+	case AFS_FTYPE_FILE:
+		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
+		inode->i_op	= &afs_file_inode_operations;
+		inode->i_fop	= &afs_file_operations;
+		inode->i_mapping->a_ops	= &afs_file_aops;
+		mapping_set_large_folios(inode->i_mapping);
+		break;
+	case AFS_FTYPE_DIR:
+		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
+		inode->i_op	= &afs_dir_inode_operations;
+		inode->i_fop	= &afs_dir_file_operations;
+		inode->i_mapping->a_ops	= &afs_dir_aops;
+		mapping_set_large_folios(inode->i_mapping);
+		break;
+	case AFS_FTYPE_SYMLINK:
+		/* Symlinks with a mode of 0644 are actually mountpoints. */
+		if ((status->mode & 0777) == 0644) {
+			inode->i_flags |= S_AUTOMOUNT;
+
+			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+
+			inode->i_mode	= S_IFDIR | 0555;
+			inode->i_op	= &afs_mntpt_inode_operations;
+			inode->i_fop	= &afs_mntpt_file_operations;
+			inode->i_mapping->a_ops	= &afs_symlink_aops;
+		} else {
+			inode->i_mode	= S_IFLNK | status->mode;
+			inode->i_op	= &afs_symlink_inode_operations;
+			inode->i_mapping->a_ops	= &afs_symlink_aops;
+		}
+		inode_nohighmem(inode);
+		break;
+	default:
+		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
+		write_sequnlock(&vnode->cb_lock);
+		return afs_protocol_error(NULL, afs_eproto_file_type);
+	}
+
+	afs_set_i_size(vnode, status->size);
+	afs_set_netfs_context(vnode);
+
+	vnode->invalid_before	= status->data_version;
+	inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);
+
+	if (!vp->scb.have_cb) {
+		/* it's a symlink we just created (the fileserver
+		 * didn't give us a callback) */
+		vnode->cb_expires_at = ktime_get_real_seconds();
+	} else {
+		vnode->cb_expires_at = vp->scb.callback.expires_at;
+		vnode->cb_server = op->server;
+		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+	}
+
+	write_sequnlock(&vnode->cb_lock);
+	return 0;
+}
+
+/*
+ * Update the core inode struct from a returned status record.
+ */
+static void afs_apply_status(struct afs_operation *op,
+			     struct afs_vnode_param *vp)
+{
+	struct afs_file_status *status = &vp->scb.status;
+	struct afs_vnode *vnode = vp->vnode;
+	struct inode *inode = &vnode->netfs.inode;
+	struct timespec64 t;
+	umode_t mode;
+	bool data_changed = false;
+	bool change_size = vp->set_size;
+
+	_enter("{%llx:%llu.%u} %s",
+	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
+	       op->type ? op->type->name : "???");
+
+	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
+
+	if (status->type != vnode->status.type) {
+		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
+			vnode->fid.vid,
+			vnode->fid.vnode,
+			vnode->fid.unique,
+			status->type, vnode->status.type);
+		afs_protocol_error(NULL, afs_eproto_bad_status);
+		return;
+	}
+
+	if (status->nlink != vnode->status.nlink)
+		set_nlink(inode, status->nlink);
+
+	if (status->owner != vnode->status.owner)
+		inode->i_uid = make_kuid(&init_user_ns, status->owner);
+
+	if (status->group != vnode->status.group)
+		inode->i_gid = make_kgid(&init_user_ns, status->group);
+
+	if (status->mode != vnode->status.mode) {
+		mode = inode->i_mode;
+		mode &= ~S_IALLUGO;
+		mode |= status->mode & S_IALLUGO;
+		WRITE_ONCE(inode->i_mode, mode);
+	}
+
+	t = status->mtime_client;
+	inode->i_mtime = t;
+	if (vp->update_ctime)
+		inode->i_ctime = op->ctime;
+
+	if (vnode->status.data_version != status->data_version)
+		data_changed = true;
+
+	vnode->status = *status;
+
+	if (vp->dv_before + vp->dv_delta != status->data_version) {
+		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
+			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
+				vnode->fid.vid, vnode->fid.vnode,
+				(unsigned long long)vp->dv_before + vp->dv_delta,
+				(unsigned long long)status->data_version,
+				op->type ? op->type->name : "???",
+				op->debug_id);
+
+		vnode->invalid_before = status->data_version;
+		if (vnode->status.type == AFS_FTYPE_DIR) {
+			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+				afs_stat_v(vnode, n_inval);
+		} else {
+			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
+		}
+		change_size = true;
+		data_changed = true;
+	} else if (vnode->status.type == AFS_FTYPE_DIR) {
+		/* Expected directory change is handled elsewhere so
+		 * that we can locally edit the directory and save on a
+		 * download.
+		 */
+		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+			data_changed = false;
+		change_size = true;
+	}
+
+	if (data_changed) {
+		inode_set_iversion_raw(inode, status->data_version);
+
+		/* Only update the size if the data version jumped.  If the
+		 * file is being modified locally, then we might have our own
+		 * idea of what the size should be that's not the same as
+		 * what's on the server.
+		 */
+		vnode->netfs.remote_i_size = status->size;
+		if (change_size) {
+			afs_set_i_size(vnode, status->size);
+			inode->i_ctime = t;
+			inode->i_atime = t;
+		}
+	}
+}
+
+/*
+ * Apply a callback to a vnode.
+ */
+static void afs_apply_callback(struct afs_operation *op,
+			       struct afs_vnode_param *vp)
+{
+	struct afs_callback *cb = &vp->scb.callback;
+	struct afs_vnode *vnode = vp->vnode;
+
+	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
+		vnode->cb_expires_at	= cb->expires_at;
+		vnode->cb_server	= op->server;
+		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+	}
+}
+
+/*
+ * Apply the received status and callback to an inode all in the same critical
+ * section to avoid races with afs_validate().
+ */
+void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
+{
+	struct afs_vnode *vnode = vp->vnode;
+
+	_enter("");
+
+	write_seqlock(&vnode->cb_lock);
+
+	if (vp->scb.have_error) {
+		/* A YFS server will return this from RemoveFile2 and AFS and
+		 * YFS will return this from InlineBulkStatus.
+		 */
+		if (vp->scb.status.abort_code == VNOVNODE) {
+			set_bit(AFS_VNODE_DELETED, &vnode->flags);
+			clear_nlink(&vnode->netfs.inode);
+			__afs_break_callback(vnode, afs_cb_break_for_deleted);
+			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
+		}
+	} else if (vp->scb.have_status) {
+		if (vp->speculative &&
+		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
+		     vp->dv_before != vnode->status.data_version))
+			/* Ignore the result of a speculative bulk status fetch
+			 * if it splits around a modification op, thereby
+			 * appearing to regress the data version.
+			 */
+			goto out;
+		afs_apply_status(op, vp);
+		if (vp->scb.have_cb)
+			afs_apply_callback(op, vp);
+	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
+		drop_nlink(&vnode->netfs.inode);
+		if (vnode->netfs.inode.i_nlink == 0) {
+			set_bit(AFS_VNODE_DELETED, &vnode->flags);
+			__afs_break_callback(vnode, afs_cb_break_for_deleted);
+		}
+	}
+
+out:
+	write_sequnlock(&vnode->cb_lock);
+
+	if (vp->scb.have_status)
+		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
+}
+
+static void afs_fetch_status_success(struct afs_operation *op)
+{
+	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
+	struct afs_vnode *vnode = vp->vnode;
+	int ret;
+
+	if (vnode->netfs.inode.i_state & I_NEW) {
+		ret = afs_inode_init_from_status(op, vp, vnode);
+		op->error = ret;
+		if (ret == 0)
+			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
+	} else {
+		afs_vnode_commit_status(op, vp);
+	}
+}
+
+const struct afs_operation_ops afs_fetch_status_operation = {
+	.issue_afs_rpc	= afs_fs_fetch_status,
+	.issue_yfs_rpc	= yfs_fs_fetch_status,
+	.success	= afs_fetch_status_success,
+	.aborted	= afs_check_for_remote_deletion,
+};
+
+/*
+ * Fetch file status from the volume.
+ */
+int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
+		     afs_access_t *_caller_access)
+{
+	struct afs_operation *op;
+
+	_enter("%s,{%llx:%llu.%u,S=%lx}",
+	       vnode->volume->name,
+	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
+	       vnode->flags);
+
+	op = afs_alloc_operation(key, vnode->volume);
+	if (IS_ERR(op))
+		return PTR_ERR(op);
+
+	afs_op_set_vnode(op, 0, vnode);
+
+	op->nr_files	= 1;
+	op->ops		= &afs_fetch_status_operation;
+	afs_begin_vnode_operation(op);
+	afs_wait_for_operation(op);
+
+	if (_caller_access)
+		*_caller_access = op->file[0].scb.status.caller_access;
+	return afs_put_operation(op);
+}
+
+/*
+ * ilookup() comparator
+ */
+int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
+{
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct afs_fid *fid = opaque;
+
+	return (fid->vnode == vnode->fid.vnode &&
+		fid->vnode_hi == vnode->fid.vnode_hi &&
+		fid->unique == vnode->fid.unique);
+}
+
+/*
+ * iget5() comparator
+ */
+static int afs_iget5_test(struct inode *inode, void *opaque)
+{
+	struct afs_vnode_param *vp = opaque;
+	//struct afs_vnode *vnode = AFS_FS_I(inode);
+
+	return afs_ilookup5_test_by_fid(inode, &vp->fid);
+}
+
+/*
+ * iget5() inode initialiser
+ */
+static int afs_iget5_set(struct inode *inode, void *opaque)
+{
+	struct afs_vnode_param *vp = opaque;
+	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+
+	vnode->volume		= as->volume;
+	vnode->fid		= vp->fid;
+
+	/* YFS supports 96-bit vnode IDs, but Linux only supports
+	 * 64-bit inode numbers.
+	 */
+	inode->i_ino		= vnode->fid.vnode;
+	inode->i_generation	= vnode->fid.unique;
+	return 0;
+}
+
+/*
+ * Get a cache cookie for an inode.
+ */
+static void afs_get_inode_cache(struct afs_vnode *vnode)
+{
+#ifdef CONFIG_AFS_FSCACHE
+	struct {
+		__be32 vnode_id;
+		__be32 unique;
+		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
+	} __packed key;
+	struct afs_vnode_cache_aux aux;
+
+	if (vnode->status.type != AFS_FTYPE_FILE) {
+		vnode->netfs.cache = NULL;
+		return;
+	}
+
+	key.vnode_id		= htonl(vnode->fid.vnode);
+	key.unique		= htonl(vnode->fid.unique);
+	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
+	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
+	afs_set_cache_aux(vnode, &aux);
+
+	afs_vnode_set_cache(vnode,
+			    fscache_acquire_cookie(
+				    vnode->volume->cache,
+				    vnode->status.type == AFS_FTYPE_FILE ?
+				    0 : FSCACHE_ADV_SINGLE_CHUNK,
+				    &key, sizeof(key),
+				    &aux, sizeof(aux),
+				    i_size_read(&vnode->netfs.inode)));
+#endif
+}
+
+/*
+ * inode retrieval
+ */
+struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
+{
+	struct afs_vnode_param *dvp = &op->file[0];
+	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
+	struct afs_vnode *vnode;
+	struct inode *inode;
+	int ret;
+
+	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
+
+	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
+	if (!inode) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	vnode = AFS_FS_I(inode);
+
+	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
+	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
+
+	/* deal with an existing inode */
+	if (!(inode->i_state & I_NEW)) {
+		_leave(" = %p", inode);
+		return inode;
+	}
+
+	ret = afs_inode_init_from_status(op, vp, vnode);
+	if (ret < 0)
+		goto bad_inode;
+
+	afs_get_inode_cache(vnode);
+
+	/* success */
+	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
+	unlock_new_inode(inode);
+	_leave(" = %p", inode);
+	return inode;
+
+	/* failure */
+bad_inode:
+	iget_failed(inode);
+	_leave(" = %d [bad]", ret);
+	return ERR_PTR(ret);
+}
+
+static int afs_iget5_set_root(struct inode *inode, void *opaque)
+{
+	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+
+	vnode->volume		= as->volume;
+	vnode->fid.vid		= as->volume->vid,
+	vnode->fid.vnode	= 1;
+	vnode->fid.unique	= 1;
+	inode->i_ino		= 1;
+	inode->i_generation	= 1;
+	return 0;
+}
+
+/*
+ * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
+ * the volume.
+ */
+struct inode *afs_root_iget(struct super_block *sb, struct key *key)
+{
+	struct afs_super_info *as = AFS_FS_S(sb);
+	struct afs_operation *op;
+	struct afs_vnode *vnode;
+	struct inode *inode;
+	int ret;
+
+	_enter(",{%llx},,", as->volume->vid);
+
+	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
+	if (!inode) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
+
+	BUG_ON(!(inode->i_state & I_NEW));
+
+	vnode = AFS_FS_I(inode);
+	vnode->cb_v_break = as->volume->cb_v_break,
+	afs_set_netfs_context(vnode);
+
+	op = afs_alloc_operation(key, as->volume);
+	if (IS_ERR(op)) {
+		ret = PTR_ERR(op);
+		goto error;
+	}
+
+	afs_op_set_vnode(op, 0, vnode);
+
+	op->nr_files	= 1;
+	op->ops		= &afs_fetch_status_operation;
+	ret = afs_do_sync_operation(op);
+	if (ret < 0)
+		goto error;
+
+	afs_get_inode_cache(vnode);
+
+	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
+	unlock_new_inode(inode);
+	_leave(" = %p", inode);
+	return inode;
+
+error:
+	iget_failed(inode);
+	_leave(" = %d [bad]", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * mark the data attached to an inode as obsolete due to a write on the server
+ * - might also want to ditch all the outstanding writes and dirty pages
+ */
+static void afs_zap_data(struct afs_vnode *vnode)
+{
+	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
+
+	afs_invalidate_cache(vnode, 0);
+
+	/* nuke all the non-dirty pages that aren't locked, mapped or being
+	 * written back in a regular file and completely discard the pages in a
+	 * directory or symlink */
+	if (S_ISREG(vnode->netfs.inode.i_mode))
+		invalidate_remote_inode(&vnode->netfs.inode);
+	else
+		invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
+}
+
+/*
+ * Check to see if we have a server currently serving this volume and that it
+ * hasn't been reinitialised or dropped from the list.
+ */
+static bool afs_check_server_good(struct afs_vnode *vnode)
+{
+	struct afs_server_list *slist;
+	struct afs_server *server;
+	bool good;
+	int i;
+
+	if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
+		return true;
+
+	rcu_read_lock();
+
+	slist = rcu_dereference(vnode->volume->servers);
+	for (i = 0; i < slist->nr_servers; i++) {
+		server = slist->servers[i].server;
+		if (server == vnode->cb_server) {
+			good = (vnode->cb_s_break == server->cb_s_break);
+			rcu_read_unlock();
+			return good;
+		}
+	}
+
+	rcu_read_unlock();
+	return false;
+}
+
+/*
+ * Check the validity of a vnode/inode.
+ */
+bool afs_check_validity(struct afs_vnode *vnode)
+{
+	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
+	time64_t now = ktime_get_real_seconds();
+	unsigned int cb_break;
+	int seq = 0;
+
+	do {
+		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
+		cb_break = vnode->cb_break;
+
+		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
+			if (vnode->cb_v_break != vnode->volume->cb_v_break)
+				need_clear = afs_cb_break_for_v_break;
+			else if (!afs_check_server_good(vnode))
+				need_clear = afs_cb_break_for_s_reinit;
+			else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
+				need_clear = afs_cb_break_for_zap;
+			else if (vnode->cb_expires_at - 10 <= now)
+				need_clear = afs_cb_break_for_lapsed;
+		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
+			;
+		} else {
+			need_clear = afs_cb_break_no_promise;
+		}
+
+	} while (need_seqretry(&vnode->cb_lock, seq));
+
+	done_seqretry(&vnode->cb_lock, seq);
+
+	if (need_clear == afs_cb_break_no_break)
+		return true;
+
+	write_seqlock(&vnode->cb_lock);
+	if (need_clear == afs_cb_break_no_promise)
+		vnode->cb_v_break = vnode->volume->cb_v_break;
+	else if (cb_break == vnode->cb_break)
+		__afs_break_callback(vnode, need_clear);
+	else
+		trace_afs_cb_miss(&vnode->fid, need_clear);
+	write_sequnlock(&vnode->cb_lock);
+	return false;
+}
+
+/*
+ * validate a vnode/inode
+ * - there are several things we need to check
+ *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
+ *     symlink)
+ *   - parent dir metadata changed (security changes)
+ *   - dentry data changed (write, truncate)
+ *   - dentry metadata changed (security changes)
+ */
+int afs_validate(struct afs_vnode *vnode, struct key *key)
+{
+	int ret;
+
+	_enter("{v={%llx:%llu} fl=%lx},%x",
+	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
+	       key_serial(key));
+
+	if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
+		if (vnode->netfs.inode.i_nlink)
+			clear_nlink(&vnode->netfs.inode);
+		goto valid;
+	}
+
+	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
+	    afs_check_validity(vnode))
+		goto valid;
+
+	down_write(&vnode->validate_lock);
+
+	/* if the promise has expired, we need to check the server again to get
+	 * a new promise - note that if the (parent) directory's metadata was
+	 * changed then the security may be different and we may no longer have
+	 * access */
+	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
+		_debug("not promised");
+		ret = afs_fetch_status(vnode, key, false, NULL);
+		if (ret < 0) {
+			if (ret == -ENOENT) {
+				set_bit(AFS_VNODE_DELETED, &vnode->flags);
+				ret = -ESTALE;
+			}
+			goto error_unlock;
+		}
+		_debug("new promise [fl=%lx]", vnode->flags);
+	}
+
+	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
+		_debug("file already deleted");
+		ret = -ESTALE;
+		goto error_unlock;
+	}
+
+	/* if the vnode's data version number changed then its contents are
+	 * different */
+	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
+		afs_zap_data(vnode);
+	up_write(&vnode->validate_lock);
+valid:
+	_leave(" = 0");
+	return 0;
+
+error_unlock:
+	up_write(&vnode->validate_lock);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * read the attributes of an inode
+ */
+int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		struct kstat *stat, u32 request_mask, unsigned int query_flags)
+{
+	struct inode *inode = d_inode(path->dentry);
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct key *key;
+	int ret, seq = 0;
+
+	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
+
+	if (vnode->volume &&
+	    !(query_flags & AT_STATX_DONT_SYNC) &&
+	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
+		key = afs_request_key(vnode->volume->cell);
+		if (IS_ERR(key))
+			return PTR_ERR(key);
+		ret = afs_validate(vnode, key);
+		key_put(key);
+		if (ret < 0)
+			return ret;
+	}
+
+	do {
+		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
+		generic_fillattr(&init_user_ns, inode, stat);
+		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
+		    stat->nlink > 0)
+			stat->nlink -= 1;
+
+		/* Lie about the size of directories.  We maintain a locally
+		 * edited copy and may make different allocation decisions on
+		 * it, but we need to give userspace the server's size.
+		 */
+		if (S_ISDIR(inode->i_mode))
+			stat->size = vnode->netfs.remote_i_size;
+	} while (need_seqretry(&vnode->cb_lock, seq));
+
+	done_seqretry(&vnode->cb_lock, seq);
+	return 0;
+}
+
+/*
+ * discard an AFS inode
+ */
+int afs_drop_inode(struct inode *inode)
+{
+	_enter("");
+
+	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
+		return generic_delete_inode(inode);
+	else
+		return generic_drop_inode(inode);
+}
+
+/*
+ * clear an AFS inode
+ */
+void afs_evict_inode(struct inode *inode)
+{
+	struct afs_vnode_cache_aux aux;
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+
+	_enter("{%llx:%llu.%d}",
+	       vnode->fid.vid,
+	       vnode->fid.vnode,
+	       vnode->fid.unique);
+
+	_debug("CLEAR INODE %p", inode);
+
+	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
+
+	truncate_inode_pages_final(&inode->i_data);
+
+	afs_set_cache_aux(vnode, &aux);
+	fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
+	clear_inode(inode);
+
+	while (!list_empty(&vnode->wb_keys)) {
+		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
+						    struct afs_wb_key, vnode_link);
+		list_del(&wbk->vnode_link);
+		afs_put_wb_key(wbk);
+	}
+
+	fscache_relinquish_cookie(afs_vnode_cache(vnode),
+				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
+
+	afs_prune_wb_keys(vnode);
+	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
+	key_put(vnode->silly_key);
+	vnode->silly_key = NULL;
+	key_put(vnode->lock_key);
+	vnode->lock_key = NULL;
+	_leave("");
+}
+
+static void afs_setattr_success(struct afs_operation *op)
+{
+	struct afs_vnode_param *vp = &op->file[0];
+	struct inode *inode = &vp->vnode->netfs.inode;
+	loff_t old_i_size = i_size_read(inode);
+
+	op->setattr.old_i_size = old_i_size;
+	afs_vnode_commit_status(op, vp);
+	/* inode->i_size has now been changed. */
+
+	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
+		loff_t size = op->setattr.attr->ia_size;
+		if (size > old_i_size)
+			pagecache_isize_extended(inode, old_i_size, size);
+	}
+}
+
+static void afs_setattr_edit_file(struct afs_operation *op)
+{
+	struct afs_vnode_param *vp = &op->file[0];
+	struct inode *inode = &vp->vnode->netfs.inode;
+
+	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
+		loff_t size = op->setattr.attr->ia_size;
+		loff_t i_size = op->setattr.old_i_size;
+
+		if (size < i_size)
+			truncate_pagecache(inode, size);
+		if (size != i_size)
+			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
+					      vp->scb.status.size);
+	}
+}
+
+static const struct afs_operation_ops afs_setattr_operation = {
+	.issue_afs_rpc	= afs_fs_setattr,
+	.issue_yfs_rpc	= yfs_fs_setattr,
+	.success	= afs_setattr_success,
+	.edit_dir	= afs_setattr_edit_file,
+};
+
+/*
+ * set the attributes of an inode
+ */
+int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		struct iattr *attr)
+{
+	const unsigned int supported =
+		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
+		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
+	struct afs_operation *op;
+	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
+	struct inode *inode = &vnode->netfs.inode;
+	loff_t i_size;
+	int ret;
+
+	_enter("{%llx:%llu},{n=%pd},%x",
+	       vnode->fid.vid, vnode->fid.vnode, dentry,
+	       attr->ia_valid);
+
+	if (!(attr->ia_valid & supported)) {
+		_leave(" = 0 [unsupported]");
+		return 0;
+	}
+
+	i_size = i_size_read(inode);
+	if (attr->ia_valid & ATTR_SIZE) {
+		if (!S_ISREG(inode->i_mode))
+			return -EISDIR;
+
+		ret = inode_newsize_ok(inode, attr->ia_size);
+		if (ret)
+			return ret;
+
+		if (attr->ia_size == i_size)
+			attr->ia_valid &= ~ATTR_SIZE;
+	}
+
+	fscache_use_cookie(afs_vnode_cache(vnode), true);
+
+	/* Prevent any new writebacks from starting whilst we do this. */
+	down_write(&vnode->validate_lock);
+
+	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
+		loff_t size = attr->ia_size;
+
+		/* Wait for any outstanding writes to the server to complete */
+		loff_t from = min(size, i_size);
+		loff_t to = max(size, i_size);
+		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
+		if (ret < 0)
+			goto out_unlock;
+
+		/* Don't talk to the server if we're just shortening in-memory
+		 * writes that haven't gone to the server yet.
+		 */
+		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
+		    attr->ia_size < i_size &&
+		    attr->ia_size > vnode->status.size) {
+			truncate_pagecache(inode, attr->ia_size);
+			fscache_resize_cookie(afs_vnode_cache(vnode),
+					      attr->ia_size);
+			i_size_write(inode, attr->ia_size);
+			ret = 0;
+			goto out_unlock;
+		}
+	}
+
+	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
+				  afs_file_key(attr->ia_file) : NULL),
+				 vnode->volume);
+	if (IS_ERR(op)) {
+		ret = PTR_ERR(op);
+		goto out_unlock;
+	}
+
+	afs_op_set_vnode(op, 0, vnode);
+	op->setattr.attr = attr;
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		op->file[0].dv_delta = 1;
+		op->file[0].set_size = true;
+	}
+	op->ctime = attr->ia_ctime;
+	op->file[0].update_ctime = 1;
+	op->file[0].modification = true;
+
+	op->ops = &afs_setattr_operation;
+	ret = afs_do_sync_operation(op);
+
+out_unlock:
+	up_write(&vnode->validate_lock);
+	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
+	_leave(" = %d", ret);
+	return ret;
+}