1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * CIFS filesystem cache interface 4 * 5 * Copyright (c) 2010 Novell, Inc. 6 * Author(s): Suresh Jayaraman <sjayaraman@suse.de> 7 * 8 */ 9 #include "fscache.h" 10 #include "cifsglob.h" 11 #include "cifs_debug.h" 12 #include "cifs_fs_sb.h" 13 #include "cifsproto.h" 14 15 /* 16 * Key for fscache inode. [!] Contents must match comparisons in cifs_find_inode(). 17 */ 18 struct cifs_fscache_inode_key { 19 20 __le64 uniqueid; /* server inode number */ 21 __le64 createtime; /* creation time on server */ 22 u8 type; /* S_IFMT file type */ 23 } __packed; 24 25 static void cifs_fscache_fill_volume_coherency( 26 struct cifs_tcon *tcon, 27 struct cifs_fscache_volume_coherency_data *cd) 28 { 29 memset(cd, 0, sizeof(*cd)); 30 cd->resource_id = cpu_to_le64(tcon->resource_id); 31 cd->vol_create_time = tcon->vol_create_time; 32 cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number); 33 } 34 35 int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) 36 { 37 struct cifs_fscache_volume_coherency_data cd; 38 struct TCP_Server_Info *server = tcon->ses->server; 39 struct fscache_volume *vcookie; 40 const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr; 41 size_t slen, i; 42 char *sharename; 43 char *key; 44 int ret = -ENOMEM; 45 46 if (tcon->fscache_acquired) 47 return 0; 48 49 mutex_lock(&tcon->fscache_lock); 50 if (tcon->fscache_acquired) { 51 mutex_unlock(&tcon->fscache_lock); 52 return 0; 53 } 54 tcon->fscache_acquired = true; 55 56 tcon->fscache = NULL; 57 switch (sa->sa_family) { 58 case AF_INET: 59 case AF_INET6: 60 break; 61 default: 62 mutex_unlock(&tcon->fscache_lock); 63 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family); 64 return -EINVAL; 65 } 66 67 memset(&key, 0, sizeof(key)); 68 69 sharename = extract_sharename(tcon->tree_name); 70 if (IS_ERR(sharename)) { 71 mutex_unlock(&tcon->fscache_lock); 72 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__); 73 return PTR_ERR(sharename); 74 } 75 76 slen = strlen(sharename); 77 for (i = 0; i < slen; i++) 78 if (sharename[i] == '/') 79 sharename[i] = ';'; 80 81 key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename); 82 if (!key) 83 goto out; 84 85 cifs_fscache_fill_volume_coherency(tcon, &cd); 86 vcookie = fscache_acquire_volume(key, 87 NULL, /* preferred_cache */ 88 &cd, sizeof(cd)); 89 cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie); 90 if (IS_ERR(vcookie)) { 91 if (vcookie != ERR_PTR(-EBUSY)) { 92 ret = PTR_ERR(vcookie); 93 goto out_2; 94 } 95 pr_err("Cache volume key already in use (%s)\n", key); 96 vcookie = NULL; 97 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, 98 netfs_trace_tcon_ref_see_fscache_collision); 99 } else { 100 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, 101 netfs_trace_tcon_ref_see_fscache_okay); 102 } 103 104 tcon->fscache = vcookie; 105 ret = 0; 106 out_2: 107 kfree(key); 108 out: 109 kfree(sharename); 110 mutex_unlock(&tcon->fscache_lock); 111 return ret; 112 } 113 114 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) 115 { 116 struct cifs_fscache_volume_coherency_data cd; 117 118 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache); 119 120 cifs_fscache_fill_volume_coherency(tcon, &cd); 121 fscache_relinquish_volume(tcon->fscache, &cd, false); 122 tcon->fscache = NULL; 123 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, 124 netfs_trace_tcon_ref_see_fscache_relinq); 125 } 126 127 void cifs_fscache_get_inode_cookie(struct inode *inode) 128 { 129 struct cifs_fscache_inode_coherency_data cd; 130 struct cifs_fscache_inode_key key; 131 struct cifsInodeInfo *cifsi = CIFS_I(inode); 132 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); 133 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); 134 135 key.uniqueid = cpu_to_le64(cifsi->uniqueid); 136 key.createtime = cpu_to_le64(cifsi->createtime); 137 key.type = (inode->i_mode & S_IFMT) >> 12; 138 cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd); 139 140 cifsi->netfs.cache = 141 fscache_acquire_cookie(tcon->fscache, 0, 142 &key, sizeof(key), 143 &cd, sizeof(cd), 144 i_size_read(&cifsi->netfs.inode)); 145 if (cifsi->netfs.cache) 146 mapping_set_release_always(inode->i_mapping); 147 } 148 149 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) 150 { 151 if (update) { 152 struct cifs_fscache_inode_coherency_data cd; 153 loff_t i_size = i_size_read(inode); 154 155 cifs_fscache_fill_coherency(inode, &cd); 156 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); 157 } else { 158 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); 159 } 160 } 161 162 void cifs_fscache_release_inode_cookie(struct inode *inode) 163 { 164 struct cifsInodeInfo *cifsi = CIFS_I(inode); 165 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 166 167 if (cookie) { 168 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); 169 fscache_relinquish_cookie(cookie, false); 170 cifsi->netfs.cache = NULL; 171 } 172 } 173 174 /* 175 * Fallback page reading interface. 176 */ 177 static int fscache_fallback_read_page(struct inode *inode, struct page *page) 178 { 179 struct netfs_cache_resources cres; 180 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 181 struct iov_iter iter; 182 struct bio_vec bvec; 183 int ret; 184 185 memset(&cres, 0, sizeof(cres)); 186 bvec_set_page(&bvec, page, PAGE_SIZE, 0); 187 iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE); 188 189 ret = fscache_begin_read_operation(&cres, cookie); 190 if (ret < 0) 191 return ret; 192 193 ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL, 194 NULL, NULL); 195 fscache_end_operation(&cres); 196 return ret; 197 } 198 199 /* 200 * Fallback page writing interface. 201 */ 202 static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len, 203 bool no_space_allocated_yet) 204 { 205 struct netfs_cache_resources cres; 206 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 207 struct iov_iter iter; 208 int ret; 209 210 memset(&cres, 0, sizeof(cres)); 211 iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len); 212 213 ret = fscache_begin_write_operation(&cres, cookie); 214 if (ret < 0) 215 return ret; 216 217 ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode), 218 no_space_allocated_yet); 219 if (ret == 0) 220 ret = fscache_write(&cres, start, &iter, NULL, NULL); 221 fscache_end_operation(&cres); 222 return ret; 223 } 224 225 /* 226 * Retrieve a page from FS-Cache 227 */ 228 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) 229 { 230 int ret; 231 232 cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n", 233 __func__, cifs_inode_cookie(inode), page, inode); 234 235 ret = fscache_fallback_read_page(inode, page); 236 if (ret < 0) 237 return ret; 238 239 /* Read completed synchronously */ 240 SetPageUptodate(page); 241 return 0; 242 } 243 244 void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) 245 { 246 cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n", 247 __func__, cifs_inode_cookie(inode), pos, len, inode); 248 249 fscache_fallback_write_pages(inode, pos, len, true); 250 } 251 252 /* 253 * Query the cache occupancy. 254 */ 255 int __cifs_fscache_query_occupancy(struct inode *inode, 256 pgoff_t first, unsigned int nr_pages, 257 pgoff_t *_data_first, 258 unsigned int *_data_nr_pages) 259 { 260 struct netfs_cache_resources cres; 261 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 262 loff_t start, data_start; 263 size_t len, data_len; 264 int ret; 265 266 ret = fscache_begin_read_operation(&cres, cookie); 267 if (ret < 0) 268 return ret; 269 270 start = first * PAGE_SIZE; 271 len = nr_pages * PAGE_SIZE; 272 ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE, 273 &data_start, &data_len); 274 if (ret == 0) { 275 *_data_first = data_start / PAGE_SIZE; 276 *_data_nr_pages = len / PAGE_SIZE; 277 } 278 279 fscache_end_operation(&cres); 280 return ret; 281 } 282