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