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 static void netfs_free_request(struct work_struct *work); 14 15 /* 16 * Allocate an I/O request and initialise it. 17 */ 18 struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 19 struct file *file, 20 loff_t start, size_t len, 21 enum netfs_io_origin origin) 22 { 23 static atomic_t debug_ids; 24 struct inode *inode = file ? file_inode(file) : mapping->host; 25 struct netfs_inode *ctx = netfs_inode(inode); 26 struct netfs_io_request *rreq; 27 mempool_t *mempool = ctx->ops->request_pool ?: &netfs_request_pool; 28 struct kmem_cache *cache = mempool->pool_data; 29 int ret; 30 31 for (;;) { 32 rreq = mempool_alloc(mempool, GFP_KERNEL); 33 if (rreq) 34 break; 35 msleep(10); 36 } 37 38 memset(rreq, 0, kmem_cache_size(cache)); 39 INIT_WORK(&rreq->cleanup_work, netfs_free_request); 40 rreq->start = start; 41 rreq->len = len; 42 rreq->origin = origin; 43 rreq->netfs_ops = ctx->ops; 44 rreq->mapping = mapping; 45 rreq->inode = inode; 46 rreq->i_size = i_size_read(inode); 47 rreq->debug_id = atomic_inc_return(&debug_ids); 48 rreq->wsize = INT_MAX; 49 rreq->io_streams[0].sreq_max_len = ULONG_MAX; 50 rreq->io_streams[0].sreq_max_segs = 0; 51 spin_lock_init(&rreq->lock); 52 INIT_LIST_HEAD(&rreq->io_streams[0].subrequests); 53 INIT_LIST_HEAD(&rreq->io_streams[1].subrequests); 54 init_waitqueue_head(&rreq->waitq); 55 refcount_set(&rreq->ref, 2); 56 57 if (origin == NETFS_READAHEAD || 58 origin == NETFS_READPAGE || 59 origin == NETFS_READ_GAPS || 60 origin == NETFS_READ_SINGLE || 61 origin == NETFS_READ_FOR_WRITE || 62 origin == NETFS_UNBUFFERED_READ || 63 origin == NETFS_DIO_READ) { 64 INIT_WORK(&rreq->work, netfs_read_collection_worker); 65 rreq->io_streams[0].avail = true; 66 } else { 67 INIT_WORK(&rreq->work, netfs_write_collection_worker); 68 } 69 70 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); 71 if (rreq->netfs_ops->init_request) { 72 ret = rreq->netfs_ops->init_request(rreq, file); 73 if (ret < 0) { 74 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 75 return ERR_PTR(ret); 76 } 77 } 78 79 atomic_inc(&ctx->io_count); 80 trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), netfs_rreq_trace_new); 81 netfs_proc_add_rreq(rreq); 82 netfs_stat(&netfs_n_rh_rreq); 83 return rreq; 84 } 85 86 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) 87 { 88 int r; 89 90 __refcount_inc(&rreq->ref, &r); 91 trace_netfs_rreq_ref(rreq->debug_id, r + 1, what); 92 } 93 94 void netfs_clear_subrequests(struct netfs_io_request *rreq) 95 { 96 struct netfs_io_subrequest *subreq; 97 struct netfs_io_stream *stream; 98 int s; 99 100 for (s = 0; s < ARRAY_SIZE(rreq->io_streams); s++) { 101 stream = &rreq->io_streams[s]; 102 while (!list_empty(&stream->subrequests)) { 103 subreq = list_first_entry(&stream->subrequests, 104 struct netfs_io_subrequest, rreq_link); 105 list_del(&subreq->rreq_link); 106 netfs_put_subrequest(subreq, netfs_sreq_trace_put_clear); 107 } 108 } 109 } 110 111 static void netfs_free_request_rcu(struct rcu_head *rcu) 112 { 113 struct netfs_io_request *rreq = container_of(rcu, struct netfs_io_request, rcu); 114 115 mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool); 116 netfs_stat_d(&netfs_n_rh_rreq); 117 } 118 119 static void netfs_free_request(struct work_struct *work) 120 { 121 struct netfs_io_request *rreq = 122 container_of(work, struct netfs_io_request, cleanup_work); 123 struct netfs_inode *ictx = netfs_inode(rreq->inode); 124 unsigned int i; 125 126 trace_netfs_rreq(rreq, netfs_rreq_trace_free); 127 128 /* Cancel/flush the result collection worker. That does not carry a 129 * ref of its own, so we must wait for it somewhere. 130 */ 131 cancel_work_sync(&rreq->work); 132 133 netfs_proc_del_rreq(rreq); 134 netfs_clear_subrequests(rreq); 135 if (rreq->netfs_ops->free_request) 136 rreq->netfs_ops->free_request(rreq); 137 if (rreq->cache_resources.ops) 138 rreq->cache_resources.ops->end_operation(&rreq->cache_resources); 139 if (rreq->direct_bv) { 140 for (i = 0; i < rreq->direct_bv_count; i++) { 141 if (rreq->direct_bv[i].bv_page) { 142 if (rreq->direct_bv_unpin) 143 unpin_user_page(rreq->direct_bv[i].bv_page); 144 } 145 } 146 kvfree(rreq->direct_bv); 147 } 148 rolling_buffer_clear(&rreq->buffer); 149 150 if (atomic_dec_and_test(&ictx->io_count)) 151 wake_up_var(&ictx->io_count); 152 call_rcu(&rreq->rcu, netfs_free_request_rcu); 153 } 154 155 void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what) 156 { 157 unsigned int debug_id; 158 bool dead; 159 int r; 160 161 if (rreq) { 162 debug_id = rreq->debug_id; 163 dead = __refcount_dec_and_test(&rreq->ref, &r); 164 trace_netfs_rreq_ref(debug_id, r - 1, what); 165 if (dead) 166 WARN_ON(!queue_work(system_unbound_wq, &rreq->cleanup_work)); 167 } 168 } 169 170 /* 171 * Allocate and partially initialise an I/O request structure. 172 */ 173 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq) 174 { 175 struct netfs_io_subrequest *subreq; 176 mempool_t *mempool = rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool; 177 struct kmem_cache *cache = mempool->pool_data; 178 179 for (;;) { 180 subreq = mempool_alloc(rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool, 181 GFP_KERNEL); 182 if (subreq) 183 break; 184 msleep(10); 185 } 186 187 memset(subreq, 0, kmem_cache_size(cache)); 188 INIT_WORK(&subreq->work, NULL); 189 INIT_LIST_HEAD(&subreq->rreq_link); 190 refcount_set(&subreq->ref, 2); 191 subreq->rreq = rreq; 192 subreq->debug_index = atomic_inc_return(&rreq->subreq_counter); 193 netfs_get_request(rreq, netfs_rreq_trace_get_subreq); 194 netfs_stat(&netfs_n_rh_sreq); 195 return subreq; 196 } 197 198 void netfs_get_subrequest(struct netfs_io_subrequest *subreq, 199 enum netfs_sreq_ref_trace what) 200 { 201 int r; 202 203 __refcount_inc(&subreq->ref, &r); 204 trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, 205 what); 206 } 207 208 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq) 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, netfs_rreq_trace_put_subreq); 218 } 219 220 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, 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); 232 } 233