1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Object lifetime handling and tracing. 3 * 4 * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #include <linux/slab.h> 9 #include "internal.h" 10 11 /* 12 * Allocate an I/O request and initialise it. 13 */ 14 struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 15 struct file *file, 16 loff_t start, size_t len, 17 enum netfs_io_origin origin) 18 { 19 static atomic_t debug_ids; 20 struct inode *inode = file ? file_inode(file) : mapping->host; 21 struct netfs_i_context *ctx = netfs_i_context(inode); 22 struct netfs_io_request *rreq; 23 int ret; 24 25 rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL); 26 if (!rreq) 27 return ERR_PTR(-ENOMEM); 28 29 rreq->start = start; 30 rreq->len = len; 31 rreq->origin = origin; 32 rreq->netfs_ops = ctx->ops; 33 rreq->mapping = mapping; 34 rreq->inode = inode; 35 rreq->i_size = i_size_read(inode); 36 rreq->debug_id = atomic_inc_return(&debug_ids); 37 INIT_LIST_HEAD(&rreq->subrequests); 38 refcount_set(&rreq->ref, 1); 39 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); 40 if (rreq->netfs_ops->init_request) { 41 ret = rreq->netfs_ops->init_request(rreq, file); 42 if (ret < 0) { 43 kfree(rreq); 44 return ERR_PTR(ret); 45 } 46 } 47 48 netfs_stat(&netfs_n_rh_rreq); 49 return rreq; 50 } 51 52 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) 53 { 54 int r; 55 56 __refcount_inc(&rreq->ref, &r); 57 trace_netfs_rreq_ref(rreq->debug_id, r + 1, what); 58 } 59 60 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async) 61 { 62 struct netfs_io_subrequest *subreq; 63 64 while (!list_empty(&rreq->subrequests)) { 65 subreq = list_first_entry(&rreq->subrequests, 66 struct netfs_io_subrequest, rreq_link); 67 list_del(&subreq->rreq_link); 68 netfs_put_subrequest(subreq, was_async, 69 netfs_sreq_trace_put_clear); 70 } 71 } 72 73 static void netfs_free_request(struct work_struct *work) 74 { 75 struct netfs_io_request *rreq = 76 container_of(work, struct netfs_io_request, work); 77 78 netfs_clear_subrequests(rreq, false); 79 if (rreq->netfs_priv) 80 rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv); 81 trace_netfs_rreq(rreq, netfs_rreq_trace_free); 82 if (rreq->cache_resources.ops) 83 rreq->cache_resources.ops->end_operation(&rreq->cache_resources); 84 kfree(rreq); 85 netfs_stat_d(&netfs_n_rh_rreq); 86 } 87 88 void netfs_put_request(struct netfs_io_request *rreq, bool was_async, 89 enum netfs_rreq_ref_trace what) 90 { 91 unsigned int debug_id = rreq->debug_id; 92 bool dead; 93 int r; 94 95 dead = __refcount_dec_and_test(&rreq->ref, &r); 96 trace_netfs_rreq_ref(debug_id, r - 1, what); 97 if (dead) { 98 if (was_async) { 99 rreq->work.func = netfs_free_request; 100 if (!queue_work(system_unbound_wq, &rreq->work)) 101 BUG(); 102 } else { 103 netfs_free_request(&rreq->work); 104 } 105 } 106 } 107 108 /* 109 * Allocate and partially initialise an I/O request structure. 110 */ 111 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq) 112 { 113 struct netfs_io_subrequest *subreq; 114 115 subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL); 116 if (subreq) { 117 INIT_LIST_HEAD(&subreq->rreq_link); 118 refcount_set(&subreq->ref, 2); 119 subreq->rreq = rreq; 120 netfs_get_request(rreq, netfs_rreq_trace_get_subreq); 121 netfs_stat(&netfs_n_rh_sreq); 122 } 123 124 return subreq; 125 } 126 127 void netfs_get_subrequest(struct netfs_io_subrequest *subreq, 128 enum netfs_sreq_ref_trace what) 129 { 130 int r; 131 132 __refcount_inc(&subreq->ref, &r); 133 trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, 134 what); 135 } 136 137 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq, 138 bool was_async) 139 { 140 struct netfs_io_request *rreq = subreq->rreq; 141 142 trace_netfs_sreq(subreq, netfs_sreq_trace_free); 143 kfree(subreq); 144 netfs_stat_d(&netfs_n_rh_sreq); 145 netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq); 146 } 147 148 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async, 149 enum netfs_sreq_ref_trace what) 150 { 151 unsigned int debug_index = subreq->debug_index; 152 unsigned int debug_id = subreq->rreq->debug_id; 153 bool dead; 154 int r; 155 156 dead = __refcount_dec_and_test(&subreq->ref, &r); 157 trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what); 158 if (dead) 159 netfs_free_subrequest(subreq, was_async); 160 } 161