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 tcon->fscache = NULL; 47 switch (sa->sa_family) { 48 case AF_INET: 49 case AF_INET6: 50 break; 51 default: 52 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family); 53 return -EINVAL; 54 } 55 56 memset(&key, 0, sizeof(key)); 57 58 sharename = extract_sharename(tcon->tree_name); 59 if (IS_ERR(sharename)) { 60 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__); 61 return PTR_ERR(sharename); 62 } 63 64 slen = strlen(sharename); 65 for (i = 0; i < slen; i++) 66 if (sharename[i] == '/') 67 sharename[i] = ';'; 68 69 key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename); 70 if (!key) 71 goto out; 72 73 cifs_fscache_fill_volume_coherency(tcon, &cd); 74 vcookie = fscache_acquire_volume(key, 75 NULL, /* preferred_cache */ 76 &cd, sizeof(cd)); 77 cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie); 78 if (IS_ERR(vcookie)) { 79 if (vcookie != ERR_PTR(-EBUSY)) { 80 ret = PTR_ERR(vcookie); 81 goto out_2; 82 } 83 pr_err("Cache volume key already in use (%s)\n", key); 84 vcookie = NULL; 85 } 86 87 tcon->fscache = vcookie; 88 ret = 0; 89 out_2: 90 kfree(key); 91 out: 92 kfree(sharename); 93 return ret; 94 } 95 96 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) 97 { 98 struct cifs_fscache_volume_coherency_data cd; 99 100 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache); 101 102 cifs_fscache_fill_volume_coherency(tcon, &cd); 103 fscache_relinquish_volume(tcon->fscache, &cd, false); 104 tcon->fscache = NULL; 105 } 106 107 void cifs_fscache_get_inode_cookie(struct inode *inode) 108 { 109 struct cifs_fscache_inode_coherency_data cd; 110 struct cifs_fscache_inode_key key; 111 struct cifsInodeInfo *cifsi = CIFS_I(inode); 112 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); 113 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); 114 115 key.uniqueid = cpu_to_le64(cifsi->uniqueid); 116 key.createtime = cpu_to_le64(cifsi->createtime); 117 key.type = (inode->i_mode & S_IFMT) >> 12; 118 cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd); 119 120 cifsi->netfs.cache = 121 fscache_acquire_cookie(tcon->fscache, 0, 122 &key, sizeof(key), 123 &cd, sizeof(cd), 124 i_size_read(&cifsi->netfs.inode)); 125 if (cifsi->netfs.cache) 126 mapping_set_release_always(inode->i_mapping); 127 } 128 129 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) 130 { 131 if (update) { 132 struct cifs_fscache_inode_coherency_data cd; 133 loff_t i_size = i_size_read(inode); 134 135 cifs_fscache_fill_coherency(inode, &cd); 136 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); 137 } else { 138 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); 139 } 140 } 141 142 void cifs_fscache_release_inode_cookie(struct inode *inode) 143 { 144 struct cifsInodeInfo *cifsi = CIFS_I(inode); 145 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 146 147 if (cookie) { 148 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); 149 fscache_relinquish_cookie(cookie, false); 150 cifsi->netfs.cache = NULL; 151 } 152 } 153 154 /* 155 * Fallback page reading interface. 156 */ 157 static int fscache_fallback_read_page(struct inode *inode, struct page *page) 158 { 159 struct netfs_cache_resources cres; 160 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 161 struct iov_iter iter; 162 struct bio_vec bvec; 163 int ret; 164 165 memset(&cres, 0, sizeof(cres)); 166 bvec_set_page(&bvec, page, PAGE_SIZE, 0); 167 iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE); 168 169 ret = fscache_begin_read_operation(&cres, cookie); 170 if (ret < 0) 171 return ret; 172 173 ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL, 174 NULL, NULL); 175 fscache_end_operation(&cres); 176 return ret; 177 } 178 179 /* 180 * Fallback page writing interface. 181 */ 182 static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len, 183 bool no_space_allocated_yet) 184 { 185 struct netfs_cache_resources cres; 186 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 187 struct iov_iter iter; 188 int ret; 189 190 memset(&cres, 0, sizeof(cres)); 191 iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len); 192 193 ret = fscache_begin_write_operation(&cres, cookie); 194 if (ret < 0) 195 return ret; 196 197 ret = cres.ops->prepare_write(&cres, &start, &len, len, i_size_read(inode), 198 no_space_allocated_yet); 199 if (ret == 0) 200 ret = fscache_write(&cres, start, &iter, NULL, NULL); 201 fscache_end_operation(&cres); 202 return ret; 203 } 204 205 /* 206 * Retrieve a page from FS-Cache 207 */ 208 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) 209 { 210 int ret; 211 212 cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n", 213 __func__, cifs_inode_cookie(inode), page, inode); 214 215 ret = fscache_fallback_read_page(inode, page); 216 if (ret < 0) 217 return ret; 218 219 /* Read completed synchronously */ 220 SetPageUptodate(page); 221 return 0; 222 } 223 224 void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) 225 { 226 cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n", 227 __func__, cifs_inode_cookie(inode), pos, len, inode); 228 229 fscache_fallback_write_pages(inode, pos, len, true); 230 } 231 232 /* 233 * Query the cache occupancy. 234 */ 235 int __cifs_fscache_query_occupancy(struct inode *inode, 236 pgoff_t first, unsigned int nr_pages, 237 pgoff_t *_data_first, 238 unsigned int *_data_nr_pages) 239 { 240 struct netfs_cache_resources cres; 241 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 242 loff_t start, data_start; 243 size_t len, data_len; 244 int ret; 245 246 ret = fscache_begin_read_operation(&cres, cookie); 247 if (ret < 0) 248 return ret; 249 250 start = first * PAGE_SIZE; 251 len = nr_pages * PAGE_SIZE; 252 ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE, 253 &data_start, &data_len); 254 if (ret == 0) { 255 *_data_first = data_start / PAGE_SIZE; 256 *_data_nr_pages = len / PAGE_SIZE; 257 } 258 259 fscache_end_operation(&cres); 260 return ret; 261 } 262