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 bool is_unbuffered = (origin == NETFS_UNBUFFERED_WRITE || 28 origin == NETFS_DIO_READ || 29 origin == NETFS_DIO_WRITE); 30 bool cached = !is_unbuffered && netfs_is_cache_enabled(ctx); 31 int ret; 32 33 for (;;) { 34 rreq = mempool_alloc(mempool, GFP_KERNEL); 35 if (rreq) 36 break; 37 msleep(10); 38 } 39 40 memset(rreq, 0, kmem_cache_size(cache)); 41 rreq->start = start; 42 rreq->len = len; 43 rreq->upper_len = len; 44 rreq->origin = origin; 45 rreq->netfs_ops = ctx->ops; 46 rreq->mapping = mapping; 47 rreq->inode = inode; 48 rreq->i_size = i_size_read(inode); 49 rreq->debug_id = atomic_inc_return(&debug_ids); 50 rreq->wsize = INT_MAX; 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_LIST_HEAD(&rreq->subrequests); 55 INIT_WORK(&rreq->work, NULL); 56 refcount_set(&rreq->ref, 1); 57 58 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); 59 if (cached) { 60 __set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags); 61 if (test_bit(NETFS_ICTX_USE_PGPRIV2, &ctx->flags)) 62 /* Filesystem uses deprecated PG_private_2 marking. */ 63 __set_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags); 64 } 65 if (file && file->f_flags & O_NONBLOCK) 66 __set_bit(NETFS_RREQ_NONBLOCK, &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 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 unsigned int i; 128 129 trace_netfs_rreq(rreq, netfs_rreq_trace_free); 130 netfs_proc_del_rreq(rreq); 131 netfs_clear_subrequests(rreq, false); 132 if (rreq->netfs_ops->free_request) 133 rreq->netfs_ops->free_request(rreq); 134 if (rreq->cache_resources.ops) 135 rreq->cache_resources.ops->end_operation(&rreq->cache_resources); 136 if (rreq->direct_bv) { 137 for (i = 0; i < rreq->direct_bv_count; i++) { 138 if (rreq->direct_bv[i].bv_page) { 139 if (rreq->direct_bv_unpin) 140 unpin_user_page(rreq->direct_bv[i].bv_page); 141 } 142 } 143 kvfree(rreq->direct_bv); 144 } 145 call_rcu(&rreq->rcu, netfs_free_request_rcu); 146 } 147 148 void netfs_put_request(struct netfs_io_request *rreq, bool was_async, 149 enum netfs_rreq_ref_trace what) 150 { 151 unsigned int debug_id; 152 bool dead; 153 int r; 154 155 if (rreq) { 156 debug_id = rreq->debug_id; 157 dead = __refcount_dec_and_test(&rreq->ref, &r); 158 trace_netfs_rreq_ref(debug_id, r - 1, what); 159 if (dead) { 160 if (was_async) { 161 rreq->work.func = netfs_free_request; 162 if (!queue_work(system_unbound_wq, &rreq->work)) 163 BUG(); 164 } else { 165 netfs_free_request(&rreq->work); 166 } 167 } 168 } 169 } 170 171 /* 172 * Allocate and partially initialise an I/O request structure. 173 */ 174 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq) 175 { 176 struct netfs_io_subrequest *subreq; 177 mempool_t *mempool = rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool; 178 struct kmem_cache *cache = mempool->pool_data; 179 180 for (;;) { 181 subreq = mempool_alloc(rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool, 182 GFP_KERNEL); 183 if (subreq) 184 break; 185 msleep(10); 186 } 187 188 memset(subreq, 0, kmem_cache_size(cache)); 189 INIT_WORK(&subreq->work, NULL); 190 INIT_LIST_HEAD(&subreq->rreq_link); 191 refcount_set(&subreq->ref, 2); 192 subreq->rreq = rreq; 193 subreq->debug_index = atomic_inc_return(&rreq->subreq_counter); 194 netfs_get_request(rreq, netfs_rreq_trace_get_subreq); 195 netfs_stat(&netfs_n_rh_sreq); 196 return subreq; 197 } 198 199 void netfs_get_subrequest(struct netfs_io_subrequest *subreq, 200 enum netfs_sreq_ref_trace what) 201 { 202 int r; 203 204 __refcount_inc(&subreq->ref, &r); 205 trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1, 206 what); 207 } 208 209 static void netfs_free_subrequest(struct netfs_io_subrequest *subreq, 210 bool was_async) 211 { 212 struct netfs_io_request *rreq = subreq->rreq; 213 214 trace_netfs_sreq(subreq, netfs_sreq_trace_free); 215 if (rreq->netfs_ops->free_subrequest) 216 rreq->netfs_ops->free_subrequest(subreq); 217 mempool_free(subreq, rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool); 218 netfs_stat_d(&netfs_n_rh_sreq); 219 netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq); 220 } 221 222 void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async, 223 enum netfs_sreq_ref_trace what) 224 { 225 unsigned int debug_index = subreq->debug_index; 226 unsigned int debug_id = subreq->rreq->debug_id; 227 bool dead; 228 int r; 229 230 dead = __refcount_dec_and_test(&subreq->ref, &r); 231 trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what); 232 if (dead) 233 netfs_free_subrequest(subreq, was_async); 234 } 235