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-rw-r--r--fs/netfs/objects.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
new file mode 100644
index 0000000000..e17cdf53f6
--- /dev/null
+++ b/fs/netfs/objects.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Object lifetime handling and tracing.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * Allocate an I/O request and initialise it.
+ */
+struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
+ struct file *file,
+ loff_t start, size_t len,
+ enum netfs_io_origin origin)
+{
+ static atomic_t debug_ids;
+ struct inode *inode = file ? file_inode(file) : mapping->host;
+ struct netfs_inode *ctx = netfs_inode(inode);
+ struct netfs_io_request *rreq;
+ int ret;
+
+ rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
+ if (!rreq)
+ return ERR_PTR(-ENOMEM);
+
+ rreq->start = start;
+ rreq->len = len;
+ rreq->origin = origin;
+ rreq->netfs_ops = ctx->ops;
+ rreq->mapping = mapping;
+ rreq->inode = inode;
+ rreq->i_size = i_size_read(inode);
+ rreq->debug_id = atomic_inc_return(&debug_ids);
+ INIT_LIST_HEAD(&rreq->subrequests);
+ refcount_set(&rreq->ref, 1);
+ __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+ if (rreq->netfs_ops->init_request) {
+ ret = rreq->netfs_ops->init_request(rreq, file);
+ if (ret < 0) {
+ kfree(rreq);
+ return ERR_PTR(ret);
+ }
+ }
+
+ netfs_stat(&netfs_n_rh_rreq);
+ return rreq;
+}
+
+void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what)
+{
+ int r;
+
+ __refcount_inc(&rreq->ref, &r);
+ trace_netfs_rreq_ref(rreq->debug_id, r + 1, what);
+}
+
+void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
+{
+ struct netfs_io_subrequest *subreq;
+
+ while (!list_empty(&rreq->subrequests)) {
+ subreq = list_first_entry(&rreq->subrequests,
+ struct netfs_io_subrequest, rreq_link);
+ list_del(&subreq->rreq_link);
+ netfs_put_subrequest(subreq, was_async,
+ netfs_sreq_trace_put_clear);
+ }
+}
+
+static void netfs_free_request(struct work_struct *work)
+{
+ struct netfs_io_request *rreq =
+ container_of(work, struct netfs_io_request, work);
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_free);
+ netfs_clear_subrequests(rreq, false);
+ if (rreq->netfs_ops->free_request)
+ rreq->netfs_ops->free_request(rreq);
+ if (rreq->cache_resources.ops)
+ rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
+ kfree(rreq);
+ netfs_stat_d(&netfs_n_rh_rreq);
+}
+
+void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
+ enum netfs_rreq_ref_trace what)
+{
+ unsigned int debug_id = rreq->debug_id;
+ bool dead;
+ int r;
+
+ dead = __refcount_dec_and_test(&rreq->ref, &r);
+ trace_netfs_rreq_ref(debug_id, r - 1, what);
+ if (dead) {
+ if (was_async) {
+ rreq->work.func = netfs_free_request;
+ if (!queue_work(system_unbound_wq, &rreq->work))
+ BUG();
+ } else {
+ netfs_free_request(&rreq->work);
+ }
+ }
+}
+
+/*
+ * Allocate and partially initialise an I/O request structure.
+ */
+struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq)
+{
+ struct netfs_io_subrequest *subreq;
+
+ subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
+ if (subreq) {
+ INIT_LIST_HEAD(&subreq->rreq_link);
+ refcount_set(&subreq->ref, 2);
+ subreq->rreq = rreq;
+ netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
+ netfs_stat(&netfs_n_rh_sreq);
+ }
+
+ return subreq;
+}
+
+void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
+ enum netfs_sreq_ref_trace what)
+{
+ int r;
+
+ __refcount_inc(&subreq->ref, &r);
+ trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1,
+ what);
+}
+
+static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
+ bool was_async)
+{
+ struct netfs_io_request *rreq = subreq->rreq;
+
+ trace_netfs_sreq(subreq, netfs_sreq_trace_free);
+ kfree(subreq);
+ netfs_stat_d(&netfs_n_rh_sreq);
+ netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
+}
+
+void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
+ enum netfs_sreq_ref_trace what)
+{
+ unsigned int debug_index = subreq->debug_index;
+ unsigned int debug_id = subreq->rreq->debug_id;
+ bool dead;
+ int r;
+
+ dead = __refcount_dec_and_test(&subreq->ref, &r);
+ trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what);
+ if (dead)
+ netfs_free_subrequest(subreq, was_async);
+}