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 -EINVAL; 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 } 112 113 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) 114 { 115 if (update) { 116 struct cifs_fscache_inode_coherency_data cd; 117 loff_t i_size = i_size_read(inode); 118 119 cifs_fscache_fill_coherency(inode, &cd); 120 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); 121 } else { 122 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); 123 } 124 } 125 126 void cifs_fscache_release_inode_cookie(struct inode *inode) 127 { 128 struct cifsInodeInfo *cifsi = CIFS_I(inode); 129 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 130 131 if (cookie) { 132 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); 133 fscache_relinquish_cookie(cookie, false); 134 cifsi->netfs.cache = NULL; 135 } 136 } 137 138 /* 139 * Fallback page reading interface. 140 */ 141 static int fscache_fallback_read_page(struct inode *inode, struct page *page) 142 { 143 struct netfs_cache_resources cres; 144 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 145 struct iov_iter iter; 146 struct bio_vec bvec; 147 int ret; 148 149 memset(&cres, 0, sizeof(cres)); 150 bvec_set_page(&bvec, page, PAGE_SIZE, 0); 151 iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE); 152 153 ret = fscache_begin_read_operation(&cres, cookie); 154 if (ret < 0) 155 return ret; 156 157 ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL, 158 NULL, NULL); 159 fscache_end_operation(&cres); 160 return ret; 161 } 162 163 /* 164 * Fallback page writing interface. 165 */ 166 static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len, 167 bool no_space_allocated_yet) 168 { 169 struct netfs_cache_resources cres; 170 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 171 struct iov_iter iter; 172 int ret; 173 174 memset(&cres, 0, sizeof(cres)); 175 iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len); 176 177 ret = fscache_begin_write_operation(&cres, cookie); 178 if (ret < 0) 179 return ret; 180 181 ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode), 182 no_space_allocated_yet); 183 if (ret == 0) 184 ret = fscache_write(&cres, start, &iter, NULL, NULL); 185 fscache_end_operation(&cres); 186 return ret; 187 } 188 189 /* 190 * Retrieve a page from FS-Cache 191 */ 192 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) 193 { 194 int ret; 195 196 cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n", 197 __func__, cifs_inode_cookie(inode), page, inode); 198 199 ret = fscache_fallback_read_page(inode, page); 200 if (ret < 0) 201 return ret; 202 203 /* Read completed synchronously */ 204 SetPageUptodate(page); 205 return 0; 206 } 207 208 void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) 209 { 210 cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n", 211 __func__, cifs_inode_cookie(inode), pos, len, inode); 212 213 fscache_fallback_write_pages(inode, pos, len, true); 214 } 215 216 /* 217 * Query the cache occupancy. 218 */ 219 int __cifs_fscache_query_occupancy(struct inode *inode, 220 pgoff_t first, unsigned int nr_pages, 221 pgoff_t *_data_first, 222 unsigned int *_data_nr_pages) 223 { 224 struct netfs_cache_resources cres; 225 struct fscache_cookie *cookie = cifs_inode_cookie(inode); 226 loff_t start, data_start; 227 size_t len, data_len; 228 int ret; 229 230 ret = fscache_begin_read_operation(&cres, cookie); 231 if (ret < 0) 232 return ret; 233 234 start = first * PAGE_SIZE; 235 len = nr_pages * PAGE_SIZE; 236 ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE, 237 &data_start, &data_len); 238 if (ret == 0) { 239 *_data_first = data_start / PAGE_SIZE; 240 *_data_nr_pages = len / PAGE_SIZE; 241 } 242 243 fscache_end_operation(&cres); 244 return ret; 245 } 246