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 } 98 99 tcon->fscache = vcookie; 100 ret = 0; 101 out_2: 102 kfree(key); 103 out: 104 kfree(sharename); 105 mutex_unlock(&tcon->fscache_lock); 106 return ret; 107 } 108 109 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) 110 { 111 struct cifs_fscache_volume_coherency_data cd; 112 113 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache); 114 115 cifs_fscache_fill_volume_coherency(tcon, &cd); 116 fscache_relinquish_volume(tcon->fscache, &cd, false); 117 tcon->fscache = NULL; 118 } 119 120 void cifs_fscache_get_inode_cookie(struct inode *inode) 121 { 122 struct cifs_fscache_inode_coherency_data cd; 123 struct cifs_fscache_inode_key key; 124 struct cifsInodeInfo *cifsi = CIFS_I(inode); 125 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); 126 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); 127 128 key.uniqueid = cpu_to_le64(cifsi->uniqueid); 129 key.createtime = cpu_to_le64(cifsi->createtime); 130 key.type = (inode->i_mode & S_IFMT) >> 12; 131 cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd); 132 133 cifsi->netfs.cache = 134 fscache_acquire_cookie(tcon->fscache, 0, 135 &key, sizeof(key), 136 &cd, sizeof(cd), 137 i_size_read(&cifsi->netfs.inode)); 138 if (cifsi->netfs.cache) 139 mapping_set_release_always(inode->i_mapping); 140 } 141 142 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) 143 { 144 if (update) { 145 struct cifs_fscache_inode_coherency_data cd; 146 loff_t i_size = i_size_read(inode); 147 148 cifs_fscache_fill_coherency(inode, &cd); 149 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); 150 } else { 151 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); 152 } 153 } 154 155 void cifs_fscache_release_inode_cookie(struct inode *inode) 156 { 157 struct cifsInodeInfo *cifsi = CIFS_I(inode); 158 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 159 160 if (cookie) { 161 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); 162 fscache_relinquish_cookie(cookie, false); 163 cifsi->netfs.cache = NULL; 164 } 165 } 166 167 /* 168 * Fallback page reading interface. 169 */ 170 static int fscache_fallback_read_page(struct inode *inode, struct page *page) 171 { 172 struct netfs_cache_resources cres; 173 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 174 struct iov_iter iter; 175 struct bio_vec bvec; 176 int ret; 177 178 memset(&cres, 0, sizeof(cres)); 179 bvec_set_page(&bvec, page, PAGE_SIZE, 0); 180 iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE); 181 182 ret = fscache_begin_read_operation(&cres, cookie); 183 if (ret < 0) 184 return ret; 185 186 ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL, 187 NULL, NULL); 188 fscache_end_operation(&cres); 189 return ret; 190 } 191 192 /* 193 * Fallback page writing interface. 194 */ 195 static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len, 196 bool no_space_allocated_yet) 197 { 198 struct netfs_cache_resources cres; 199 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 200 struct iov_iter iter; 201 int ret; 202 203 memset(&cres, 0, sizeof(cres)); 204 iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len); 205 206 ret = fscache_begin_write_operation(&cres, cookie); 207 if (ret < 0) 208 return ret; 209 210 ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode), 211 no_space_allocated_yet); 212 if (ret == 0) 213 ret = fscache_write(&cres, start, &iter, NULL, NULL); 214 fscache_end_operation(&cres); 215 return ret; 216 } 217 218 /* 219 * Retrieve a page from FS-Cache 220 */ 221 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) 222 { 223 int ret; 224 225 cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n", 226 __func__, cifs_inode_cookie(inode), page, inode); 227 228 ret = fscache_fallback_read_page(inode, page); 229 if (ret < 0) 230 return ret; 231 232 /* Read completed synchronously */ 233 SetPageUptodate(page); 234 return 0; 235 } 236 237 void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) 238 { 239 cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n", 240 __func__, cifs_inode_cookie(inode), pos, len, inode); 241 242 fscache_fallback_write_pages(inode, pos, len, true); 243 } 244 245 /* 246 * Query the cache occupancy. 247 */ 248 int __cifs_fscache_query_occupancy(struct inode *inode, 249 pgoff_t first, unsigned int nr_pages, 250 pgoff_t *_data_first, 251 unsigned int *_data_nr_pages) 252 { 253 struct netfs_cache_resources cres; 254 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 255 loff_t start, data_start; 256 size_t len, data_len; 257 int ret; 258 259 ret = fscache_begin_read_operation(&cres, cookie); 260 if (ret < 0) 261 return ret; 262 263 start = first * PAGE_SIZE; 264 len = nr_pages * PAGE_SIZE; 265 ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE, 266 &data_start, &data_len); 267 if (ret == 0) { 268 *_data_first = data_start / PAGE_SIZE; 269 *_data_nr_pages = len / PAGE_SIZE; 270 } 271 272 fscache_end_operation(&cres); 273 return ret; 274 } 275