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 <linux/mempool.h> 10 #include <linux/delay.h> 11 #include "internal.h" 12 13 /* 14 * Allocate an I/O request and initialise it. 15 */ 16 struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 17 struct file *file, 18 loff_t start, size_t len, 19 enum netfs_io_origin origin) 20 { 21 static atomic_t debug_ids; 22 struct inode *inode = file ? file_inode(file) : mapping->host; 23 struct netfs_inode *ctx = netfs_inode(inode); 24 struct netfs_io_request *rreq; 25 mempool_t *mempool = ctx->ops->request_pool ?: &netfs_request_pool; 26 struct kmem_cache *cache = mempool->pool_data; 27 int ret; 28 29 for (;;) { 30 rreq = mempool_alloc(mempool, GFP_KERNEL); 31 if (rreq) 32 break; 33 msleep(10); 34 } 35 36 memset(rreq, 0, kmem_cache_size(cache)); 37 rreq->start = start; 38 rreq->len = len; 39 rreq->origin = origin; 40 rreq->netfs_ops = ctx->ops; 41 rreq->mapping = mapping; 42 rreq->inode = inode; 43 rreq->i_size = i_size_read(inode); 44 rreq->debug_id = atomic_inc_return(&debug_ids); 45 rreq->wsize = INT_MAX; 46 rreq->io_streams[0].sreq_max_len = ULONG_MAX; 47 rreq->io_streams[0].sreq_max_segs = 0; 48 spin_lock_init(&rreq->lock); 49 INIT_LIST_HEAD(&rreq->io_streams[0].subrequests); 50 INIT_LIST_HEAD(&rreq->io_streams[1].subrequests); 51 init_waitqueue_head(&rreq->waitq); 52 refcount_set(&rreq->ref, 1); 53 54 if (origin == NETFS_READAHEAD || 55 origin == NETFS_READPAGE || 56 origin == NETFS_READ_GAPS || 57 origin == NETFS_READ_SINGLE || 58 origin == NETFS_READ_FOR_WRITE || 59 origin == NETFS_DIO_READ) { 60 INIT_WORK(&rreq->work, netfs_read_collection_worker); 61 rreq->io_streams[0].avail = true; 62 } else { 63 INIT_WORK(&rreq->work, netfs_write_collection_worker); 64 } 65 66 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); 67 if (rreq->netfs_ops->init_request) { 68 ret = rreq->netfs_ops->init_request(rreq, file); 69 if (ret < 0) { 70 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 71 return ERR_PTR(ret); 72 } 73 } 74 75 atomic_inc(&ctx->io_count); 76 trace_netfs_rreq_ref(rreq->debug_id, 1, netfs_rreq_trace_new); 77 netfs_proc_add_rreq(rreq); 78 netfs_stat(&netfs_n_rh_rreq); 79 return rreq; 80 } 81 82 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) 83 { 84 int r; 85 86 __refcount_inc(&rreq->ref, &r); 87 trace_netfs_rreq_ref(rreq->debug_id, r + 1, what); 88 } 89 90 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async) 91 { 92 struct netfs_io_subrequest *subreq; 93 struct netfs_io_stream *stream; 94 int s; 95 96 for (s = 0; s < ARRAY_SIZE(rreq->io_streams); s++) { 97 stream = &rreq->io_streams[s]; 98 while (!list_empty(&stream->subrequests)) { 99 subreq = list_first_entry(&stream->subrequests, 100 struct netfs_io_subrequest, rreq_link); 101 list_del(&subreq->rreq_link); 102 netfs_put_subrequest(subreq, was_async, 103 netfs_sreq_trace_put_clear); 104 } 105 } 106 } 107 108 static void netfs_free_request_rcu(struct rcu_head *rcu) 109 { 110 struct netfs_io_request *rreq = container_of(rcu, struct netfs_io_request, rcu); 111 112 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 113 netfs_stat_d(&netfs_n_rh_rreq); 114 } 115 116 static void netfs_free_request(struct work_struct *work) 117 { 118 struct netfs_io_request *rreq = 119 container_of(work, struct netfs_io_request, work); 120 struct netfs_inode *ictx = netfs_inode(rreq->inode); 121 unsigned int i; 122 123 trace_netfs_rreq(rreq, netfs_rreq_trace_free); 124 netfs_proc_del_rreq(rreq); 125 netfs_clear_subrequests(rreq, false); 126 if (rreq->netfs_ops->free_request) 127 rreq->netfs_ops->free_request(rreq); 128 if (rreq->cache_resources.ops) 129 rreq->cache_resources.ops->end_operation(&rreq->cache_resources); 130 if (rreq->direct_bv) { 131 for (i = 0; i < rreq->direct_bv_count; i++) { 132 if (rreq->direct_bv[i].bv_page) { 133 if (rreq->direct_bv_unpin) 134 unpin_user_page(rreq->direct_bv[i].bv_page); 135 } 136 } 137 kvfree(rreq->direct_bv); 138 } 139 rolling_buffer_clear(&rreq->buffer); 140 141 if (atomic_dec_and_test(&ictx->io_count)) 142 wake_up_var(&ictx->io_count); 143 call_rcu(&rreq->rcu, netfs_free_request_rcu); 144 } 145 146 void netfs_put_request(struct netfs_io_request *rreq, bool was_async, 147 enum netfs_rreq_ref_trace what) 148 { 149 unsigned int debug_id; 150 bool dead; 151 int r; 152 153 if (rreq) { 154 debug_id = rreq->debug_id; 155 dead = __refcount_dec_and_test(&rreq->ref, &r); 156 trace_netfs_rreq_ref(debug_id, r - 1, what); 157 if (dead) { 158 if (was_async) { 159 rreq->work.func = netfs_free_request; 160 if (!queue_work(system_unbound_wq, &rreq->work)) 161 WARN_ON(1); 162 } else { 163 netfs_free_request(&rreq->work); 164 } 165 } 166 } 167 } 168 169 /* 170 * Allocate and partially initialise an I/O request structure. 171 */ 172 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq) 173 { 174 struct netfs_io_subrequest *subreq; 175 mempool_t *mempool = rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool; 176 struct kmem_cache *cache = mempool->pool_data; 177 178 for (;;) { 179 subreq = mempool_alloc(rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool, 180 GFP_KERNEL); 181 if (subreq) 182 break; 183 msleep(10); 184 } 185 186 memset(subreq, 0, kmem_cache_size(cache)); 187 INIT_WORK(&subreq->work, NULL); 188 INIT_LIST_HEAD(&subreq->rreq_link); 189 refcount_set(&subreq->ref, 2); 190 subreq->rreq = rreq; 191 subreq->debug_index = atomic_inc_return(&rreq->subreq_counter); 192 netfs_get_request(rreq, netfs_rreq_trace_get_subreq); 193 netfs_stat(&netfs_n_rh_sreq); 194 return subreq; 195 } 196 197 void netfs_get_subrequest(struct netfs_io_subrequest *subreq, 198 enum netfs_sreq_ref_trace what) 199 { 200 int r; 201 202 __refcount_inc(&subreq->ref, &r); 203 trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, 204 what); 205 } 206 207 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq, 208 bool was_async) 209 { 210 struct netfs_io_request *rreq = subreq->rreq; 211 212 trace_netfs_sreq(subreq, netfs_sreq_trace_free); 213 if (rreq->netfs_ops->free_subrequest) 214 rreq->netfs_ops->free_subrequest(subreq); 215 mempool_free(subreq, rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool); 216 netfs_stat_d(&netfs_n_rh_sreq); 217 netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq); 218 } 219 220 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async, 221 enum netfs_sreq_ref_trace what) 222 { 223 unsigned int debug_index = subreq->debug_index; 224 unsigned int debug_id = subreq->rreq->debug_id; 225 bool dead; 226 int r; 227 228 dead = __refcount_dec_and_test(&subreq->ref, &r); 229 trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what); 230 if (dead) 231 netfs_free_subrequest(subreq, was_async); 232 } 233