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_LIST_HEAD(&rreq->subrequests); 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_FOR_WRITE || 58 origin == NETFS_DIO_READ) 59 INIT_WORK(&rreq->work, netfs_read_termination_worker); 60 else 61 INIT_WORK(&rreq->work, netfs_write_collection_worker); 62 63 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); 64 if (file && file->f_flags & O_NONBLOCK) 65 __set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags); 66 if (rreq->netfs_ops->init_request) { 67 ret = rreq->netfs_ops->init_request(rreq, file); 68 if (ret < 0) { 69 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 70 return ERR_PTR(ret); 71 } 72 } 73 74 atomic_inc(&ctx->io_count); 75 trace_netfs_rreq_ref(rreq->debug_id, 1, netfs_rreq_trace_new); 76 netfs_proc_add_rreq(rreq); 77 netfs_stat(&netfs_n_rh_rreq); 78 return rreq; 79 } 80 81 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) 82 { 83 int r; 84 85 __refcount_inc(&rreq->ref, &r); 86 trace_netfs_rreq_ref(rreq->debug_id, r + 1, what); 87 } 88 89 void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async) 90 { 91 struct netfs_io_subrequest *subreq; 92 struct netfs_io_stream *stream; 93 int s; 94 95 while (!list_empty(&rreq->subrequests)) { 96 subreq = list_first_entry(&rreq->subrequests, 97 struct netfs_io_subrequest, rreq_link); 98 list_del(&subreq->rreq_link); 99 netfs_put_subrequest(subreq, was_async, 100 netfs_sreq_trace_put_clear); 101 } 102 103 for (s = 0; s < ARRAY_SIZE(rreq->io_streams); s++) { 104 stream = &rreq->io_streams[s]; 105 while (!list_empty(&stream->subrequests)) { 106 subreq = list_first_entry(&stream->subrequests, 107 struct netfs_io_subrequest, rreq_link); 108 list_del(&subreq->rreq_link); 109 netfs_put_subrequest(subreq, was_async, 110 netfs_sreq_trace_put_clear); 111 } 112 } 113 } 114 115 static void netfs_free_request_rcu(struct rcu_head *rcu) 116 { 117 struct netfs_io_request *rreq = container_of(rcu, struct netfs_io_request, rcu); 118 119 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 120 netfs_stat_d(&netfs_n_rh_rreq); 121 } 122 123 static void netfs_free_request(struct work_struct *work) 124 { 125 struct netfs_io_request *rreq = 126 container_of(work, struct netfs_io_request, work); 127 struct netfs_inode *ictx = netfs_inode(rreq->inode); 128 unsigned int i; 129 130 trace_netfs_rreq(rreq, netfs_rreq_trace_free); 131 netfs_proc_del_rreq(rreq); 132 netfs_clear_subrequests(rreq, false); 133 if (rreq->netfs_ops->free_request) 134 rreq->netfs_ops->free_request(rreq); 135 if (rreq->cache_resources.ops) 136 rreq->cache_resources.ops->end_operation(&rreq->cache_resources); 137 if (rreq->direct_bv) { 138 for (i = 0; i < rreq->direct_bv_count; i++) { 139 if (rreq->direct_bv[i].bv_page) { 140 if (rreq->direct_bv_unpin) 141 unpin_user_page(rreq->direct_bv[i].bv_page); 142 } 143 } 144 kvfree(rreq->direct_bv); 145 } 146 netfs_clear_buffer(rreq); 147 148 if (atomic_dec_and_test(&ictx->io_count)) 149 wake_up_var(&ictx->io_count); 150 call_rcu(&rreq->rcu, netfs_free_request_rcu); 151 } 152 153 void netfs_put_request(struct netfs_io_request *rreq, bool was_async, 154 enum netfs_rreq_ref_trace what) 155 { 156 unsigned int debug_id; 157 bool dead; 158 int r; 159 160 if (rreq) { 161 debug_id = rreq->debug_id; 162 dead = __refcount_dec_and_test(&rreq->ref, &r); 163 trace_netfs_rreq_ref(debug_id, r - 1, what); 164 if (dead) { 165 if (was_async) { 166 rreq->work.func = netfs_free_request; 167 if (!queue_work(system_unbound_wq, &rreq->work)) 168 WARN_ON(1); 169 } else { 170 netfs_free_request(&rreq->work); 171 } 172 } 173 } 174 } 175 176 /* 177 * Allocate and partially initialise an I/O request structure. 178 */ 179 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq) 180 { 181 struct netfs_io_subrequest *subreq; 182 mempool_t *mempool = rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool; 183 struct kmem_cache *cache = mempool->pool_data; 184 185 for (;;) { 186 subreq = mempool_alloc(rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool, 187 GFP_KERNEL); 188 if (subreq) 189 break; 190 msleep(10); 191 } 192 193 memset(subreq, 0, kmem_cache_size(cache)); 194 INIT_WORK(&subreq->work, NULL); 195 INIT_LIST_HEAD(&subreq->rreq_link); 196 refcount_set(&subreq->ref, 2); 197 subreq->rreq = rreq; 198 subreq->debug_index = atomic_inc_return(&rreq->subreq_counter); 199 netfs_get_request(rreq, netfs_rreq_trace_get_subreq); 200 netfs_stat(&netfs_n_rh_sreq); 201 return subreq; 202 } 203 204 void netfs_get_subrequest(struct netfs_io_subrequest *subreq, 205 enum netfs_sreq_ref_trace what) 206 { 207 int r; 208 209 __refcount_inc(&subreq->ref, &r); 210 trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, 211 what); 212 } 213 214 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq, 215 bool was_async) 216 { 217 struct netfs_io_request *rreq = subreq->rreq; 218 219 trace_netfs_sreq(subreq, netfs_sreq_trace_free); 220 if (rreq->netfs_ops->free_subrequest) 221 rreq->netfs_ops->free_subrequest(subreq); 222 mempool_free(subreq, rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool); 223 netfs_stat_d(&netfs_n_rh_sreq); 224 netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq); 225 } 226 227 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async, 228 enum netfs_sreq_ref_trace what) 229 { 230 unsigned int debug_index = subreq->debug_index; 231 unsigned int debug_id = subreq->rreq->debug_id; 232 bool dead; 233 int r; 234 235 dead = __refcount_dec_and_test(&subreq->ref, &r); 236 trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what); 237 if (dead) 238 netfs_free_subrequest(subreq, was_async); 239 } 240