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-rw-r--r--fs/afs/fs_operation.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/fs/afs/fs_operation.c b/fs/afs/fs_operation.c
new file mode 100644
index 000000000000..f7a768d12141
--- /dev/null
+++ b/fs/afs/fs_operation.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Fileserver-directed operation handling.
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include "internal.h"
+
+static atomic_t afs_operation_debug_counter;
+
+/*
+ * Create an operation against a volume.
+ */
+struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *volume)
+{
+ struct afs_operation *op;
+
+ _enter("");
+
+ op = kzalloc(sizeof(*op), GFP_KERNEL);
+ if (!op)
+ return ERR_PTR(-ENOMEM);
+
+ if (!key) {
+ key = afs_request_key(volume->cell);
+ if (IS_ERR(key)) {
+ kfree(op);
+ return ERR_CAST(key);
+ }
+ } else {
+ key_get(key);
+ }
+
+ op->key = key;
+ op->volume = afs_get_volume(volume);
+ op->net = volume->cell->net;
+ op->cb_v_break = volume->cb_v_break;
+ op->debug_id = atomic_inc_return(&afs_operation_debug_counter);
+ op->error = -EDESTADDRREQ;
+ op->ac.error = SHRT_MAX;
+
+ _leave(" = [op=%08x]", op->debug_id);
+ return op;
+}
+
+/*
+ * Lock the vnode(s) being operated upon.
+ */
+static bool afs_get_io_locks(struct afs_operation *op)
+{
+ struct afs_vnode *vnode = op->file[0].vnode;
+ struct afs_vnode *vnode2 = op->file[1].vnode;
+
+ _enter("");
+
+ if (op->flags & AFS_OPERATION_UNINTR) {
+ mutex_lock(&vnode->io_lock);
+ op->flags |= AFS_OPERATION_LOCK_0;
+ _leave(" = t [1]");
+ return true;
+ }
+
+ if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2)
+ vnode2 = NULL;
+
+ if (vnode2 > vnode)
+ swap(vnode, vnode2);
+
+ if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
+ op->error = -EINTR;
+ op->flags |= AFS_OPERATION_STOP;
+ _leave(" = f [I 0]");
+ return false;
+ }
+ op->flags |= AFS_OPERATION_LOCK_0;
+
+ if (vnode2) {
+ if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
+ op->error = -EINTR;
+ op->flags |= AFS_OPERATION_STOP;
+ mutex_unlock(&vnode->io_lock);
+ op->flags &= ~AFS_OPERATION_LOCK_0;
+ _leave(" = f [I 1]");
+ return false;
+ }
+ op->flags |= AFS_OPERATION_LOCK_1;
+ }
+
+ _leave(" = t [2]");
+ return true;
+}
+
+static void afs_drop_io_locks(struct afs_operation *op)
+{
+ struct afs_vnode *vnode = op->file[0].vnode;
+ struct afs_vnode *vnode2 = op->file[1].vnode;
+
+ _enter("");
+
+ if (op->flags & AFS_OPERATION_LOCK_1)
+ mutex_unlock(&vnode2->io_lock);
+ if (op->flags & AFS_OPERATION_LOCK_0)
+ mutex_unlock(&vnode->io_lock);
+}
+
+static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp,
+ unsigned int index)
+{
+ struct afs_vnode *vnode = vp->vnode;
+
+ if (vnode) {
+ vp->fid = vnode->fid;
+ vp->dv_before = vnode->status.data_version;
+ vp->cb_break_before = afs_calc_vnode_cb_break(vnode);
+ if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
+ op->flags |= AFS_OPERATION_CUR_ONLY;
+ }
+
+ if (vp->fid.vnode)
+ _debug("PREP[%u] {%llx:%llu.%u}",
+ index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
+}
+
+/*
+ * Begin an operation on the fileserver.
+ *
+ * Fileserver operations are serialised on the server by vnode, so we serialise
+ * them here also using the io_lock.
+ */
+bool afs_begin_vnode_operation(struct afs_operation *op)
+{
+ struct afs_vnode *vnode = op->file[0].vnode;
+
+ ASSERT(vnode);
+
+ _enter("");
+
+ if (op->file[0].need_io_lock)
+ if (!afs_get_io_locks(op))
+ return false;
+
+ read_seqlock_excl(&vnode->cb_lock);
+ op->cbi = afs_get_cb_interest(
+ rcu_dereference_protected(vnode->cb_interest,
+ lockdep_is_held(&vnode->cb_lock.lock)));
+ read_sequnlock_excl(&vnode->cb_lock);
+
+ afs_prepare_vnode(op, &op->file[0], 0);
+ afs_prepare_vnode(op, &op->file[1], 1);
+ op->cb_v_break = op->volume->cb_v_break;
+ _leave(" = true");
+ return true;
+}
+
+/*
+ * Tidy up a filesystem cursor and unlock the vnode.
+ */
+static void afs_end_vnode_operation(struct afs_operation *op)
+{
+ _enter("");
+
+ if (op->error == -EDESTADDRREQ ||
+ op->error == -EADDRNOTAVAIL ||
+ op->error == -ENETUNREACH ||
+ op->error == -EHOSTUNREACH)
+ afs_dump_edestaddrreq(op);
+
+ afs_drop_io_locks(op);
+
+ if (op->error == -ECONNABORTED)
+ op->error = afs_abort_to_error(op->ac.abort_code);
+}
+
+/*
+ * Wait for an in-progress operation to complete.
+ */
+void afs_wait_for_operation(struct afs_operation *op)
+{
+ _enter("");
+
+ while (afs_select_fileserver(op)) {
+ op->cb_s_break = op->cbi->server->cb_s_break;
+ if (test_bit(AFS_SERVER_FL_IS_YFS, &op->cbi->server->flags) &&
+ op->ops->issue_yfs_rpc)
+ op->ops->issue_yfs_rpc(op);
+ else
+ op->ops->issue_afs_rpc(op);
+
+ op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
+ }
+
+ if (op->error == 0) {
+ _debug("success");
+ op->ops->success(op);
+ }
+
+ afs_end_vnode_operation(op);
+
+ if (op->error == 0 && op->ops->edit_dir) {
+ _debug("edit_dir");
+ op->ops->edit_dir(op);
+ }
+ _leave("");
+}
+
+/*
+ * Dispose of an operation.
+ */
+int afs_put_operation(struct afs_operation *op)
+{
+ int i, ret = op->error;
+
+ _enter("op=%08x,%d", op->debug_id, ret);
+
+ if (op->ops && op->ops->put)
+ op->ops->put(op);
+ if (op->file[0].put_vnode)
+ iput(&op->file[0].vnode->vfs_inode);
+ if (op->file[1].put_vnode)
+ iput(&op->file[1].vnode->vfs_inode);
+
+ if (op->more_files) {
+ for (i = 0; i < op->nr_files - 2; i++)
+ if (op->more_files[i].put_vnode)
+ iput(&op->more_files[i].vnode->vfs_inode);
+ kfree(op->more_files);
+ }
+
+ afs_end_cursor(&op->ac);
+ afs_put_cb_interest(op->net, op->cbi);
+ afs_put_serverlist(op->net, op->server_list);
+ afs_put_volume(op->net, op->volume);
+ kfree(op);
+ return ret;
+}
+
+int afs_do_sync_operation(struct afs_operation *op)
+{
+ afs_begin_vnode_operation(op);
+ afs_wait_for_operation(op);
+ return afs_put_operation(op);
+}