fs/cifs/fscache.c

   1 /*
   2  *   fs/cifs/fscache.c - CIFS filesystem cache interface
   3  *
   4  *   Copyright (c) 2010 Novell, Inc.
   5  *   Author(s): Suresh Jayaraman <sjayaraman@suse.de>
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21 #include "fscache.h"
  22 #include "cifsglob.h"
  23 #include "cifs_debug.h"
  24 #include "cifs_fs_sb.h"
  25
  26 /*
  27  * Key layout of CIFS server cache index object
  28  */
  29 struct cifs_server_key {
  30         struct {
  31                 uint16_t        family;         /* address family */
  32                 __be16          port;           /* IP port */
  33         } hdr;
  34         union {
  35                 struct in_addr  ipv4_addr;
  36                 struct in6_addr ipv6_addr;
  37         };
  38 } __packed;
  39
  40 /*
  41  * Get a cookie for a server object keyed by {IPaddress,port,family} tuple
  42  */
  43 void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
  44 {
  45         const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
  46         const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
  47         const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
  48         struct cifs_server_key key;
  49         uint16_t key_len = sizeof(key.hdr);
  50
  51         memset(&key, 0, sizeof(key));
  52
  53         /*
  54          * Should not be a problem as sin_family/sin6_family overlays
  55          * sa_family field
  56          */
  57         key.hdr.family = sa->sa_family;
  58         switch (sa->sa_family) {
  59         case AF_INET:
  60                 key.hdr.port = addr->sin_port;
  61                 key.ipv4_addr = addr->sin_addr;
  62                 key_len += sizeof(key.ipv4_addr);
  63                 break;
  64
  65         case AF_INET6:
  66                 key.hdr.port = addr6->sin6_port;
  67                 key.ipv6_addr = addr6->sin6_addr;
  68                 key_len += sizeof(key.ipv6_addr);
  69                 break;
  70
  71         default:
  72                 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
  73                 server->fscache = NULL;
  74                 return;
  75         }
  76
  77         server->fscache =
  78                 fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
  79                                        &cifs_fscache_server_index_def,
  80                                        &key, key_len,
  81                                        NULL, 0,
  82                                        server, 0, true);
  83         cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
  84                  __func__, server, server->fscache);
  85 }
  86
  87 void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
  88 {
  89         cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
  90                  __func__, server, server->fscache);
  91         fscache_relinquish_cookie(server->fscache, NULL, false);
  92         server->fscache = NULL;
  93 }
  94
  95 void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
  96 {
  97         struct TCP_Server_Info *server = tcon->ses->server;
  98         char *sharename;
  99
 100         sharename = extract_sharename(tcon->treeName);
 101         if (IS_ERR(sharename)) {
 102                 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
 103                 tcon->fscache = NULL;
 104                 return;
 105         }
 106
 107         tcon->fscache =
 108                 fscache_acquire_cookie(server->fscache,
 109                                        &cifs_fscache_super_index_def,
 110                                        sharename, strlen(sharename),
 111                                        &tcon->resource_id, sizeof(tcon->resource_id),
 112                                        tcon, 0, true);
 113         kfree(sharename);
 114         cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
 115                  __func__, server->fscache, tcon->fscache);
 116 }
 117
 118 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 119 {
 120         cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
 121         fscache_relinquish_cookie(tcon->fscache, &tcon->resource_id, false);
 122         tcon->fscache = NULL;
 123 }
 124
 125 static void cifs_fscache_acquire_inode_cookie(struct cifsInodeInfo *cifsi,
 126                                               struct cifs_tcon *tcon)
 127 {
 128         struct cifs_fscache_inode_auxdata auxdata;
 129
 130         memset(&auxdata, 0, sizeof(auxdata));
 131         auxdata.eof = cifsi->server_eof;
 132         auxdata.last_write_time = timespec64_to_timespec(cifsi->vfs_inode.i_mtime);
 133         auxdata.last_change_time = timespec64_to_timespec(cifsi->vfs_inode.i_ctime);
 134
 135         cifsi->fscache =
 136                 fscache_acquire_cookie(tcon->fscache,
 137                                        &cifs_fscache_inode_object_def,
 138                                        &cifsi->uniqueid, sizeof(cifsi->uniqueid),
 139                                        &auxdata, sizeof(auxdata),
 140                                        cifsi, cifsi->vfs_inode.i_size, true);
 141 }
 142
 143 static void cifs_fscache_enable_inode_cookie(struct inode *inode)
 144 {
 145         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 146         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 147         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 148
 149         if (cifsi->fscache)
 150                 return;
 151
 152         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE))
 153                 return;
 154
 155         cifs_fscache_acquire_inode_cookie(cifsi, tcon);
 156
 157         cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
 158                  __func__, tcon->fscache, cifsi->fscache);
 159 }
 160
 161 void cifs_fscache_release_inode_cookie(struct inode *inode)
 162 {
 163         struct cifs_fscache_inode_auxdata auxdata;
 164         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 165
 166         if (cifsi->fscache) {
 167                 memset(&auxdata, 0, sizeof(auxdata));
 168                 auxdata.eof = cifsi->server_eof;
 169                 auxdata.last_write_time = timespec64_to_timespec(cifsi->vfs_inode.i_mtime);
 170                 auxdata.last_change_time = timespec64_to_timespec(cifsi->vfs_inode.i_ctime);
 171
 172                 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
 173                 fscache_relinquish_cookie(cifsi->fscache, &auxdata, false);
 174                 cifsi->fscache = NULL;
 175         }
 176 }
 177
 178 static void cifs_fscache_disable_inode_cookie(struct inode *inode)
 179 {
 180         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 181
 182         if (cifsi->fscache) {
 183                 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
 184                 fscache_uncache_all_inode_pages(cifsi->fscache, inode);
 185                 fscache_relinquish_cookie(cifsi->fscache, NULL, true);
 186                 cifsi->fscache = NULL;
 187         }
 188 }
 189
 190 void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
 191 {
 192         if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
 193                 cifs_fscache_disable_inode_cookie(inode);
 194         else
 195                 cifs_fscache_enable_inode_cookie(inode);
 196 }
 197
 198 void cifs_fscache_reset_inode_cookie(struct inode *inode)
 199 {
 200         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 201         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 202         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 203         struct fscache_cookie *old = cifsi->fscache;
 204
 205         if (cifsi->fscache) {
 206                 /* retire the current fscache cache and get a new one */
 207                 fscache_relinquish_cookie(cifsi->fscache, NULL, true);
 208
 209                 cifs_fscache_acquire_inode_cookie(cifsi, tcon);
 210                 cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
 211                          __func__, cifsi->fscache, old);
 212         }
 213 }
 214
 215 int cifs_fscache_release_page(struct page *page, gfp_t gfp)
 216 {
 217         if (PageFsCache(page)) {
 218                 struct inode *inode = page->mapping->host;
 219                 struct cifsInodeInfo *cifsi = CIFS_I(inode);
 220
 221                 cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
 222                          __func__, page, cifsi->fscache);
 223                 if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
 224                         return 0;
 225         }
 226
 227         return 1;
 228 }
 229
 230 static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
 231                                                 int error)
 232 {
 233         cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, page, error);
 234         if (!error)
 235                 SetPageUptodate(page);
 236         unlock_page(page);
 237 }
 238
 239 /*
 240  * Retrieve a page from FS-Cache
 241  */
 242 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 243 {
 244         int ret;
 245
 246         cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
 247                  __func__, CIFS_I(inode)->fscache, page, inode);
 248         ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
 249                                          cifs_readpage_from_fscache_complete,
 250                                          NULL,
 251                                          GFP_KERNEL);
 252         switch (ret) {
 253
 254         case 0: /* page found in fscache, read submitted */
 255                 cifs_dbg(FYI, "%s: submitted\n", __func__);
 256                 return ret;
 257         case -ENOBUFS:  /* page won't be cached */
 258         case -ENODATA:  /* page not in cache */
 259                 cifs_dbg(FYI, "%s: %d\n", __func__, ret);
 260                 return 1;
 261
 262         default:
 263                 cifs_dbg(VFS, "unknown error ret = %d\n", ret);
 264         }
 265         return ret;
 266 }
 267
 268 /*
 269  * Retrieve a set of pages from FS-Cache
 270  */
 271 int __cifs_readpages_from_fscache(struct inode *inode,
 272                                 struct address_space *mapping,
 273                                 struct list_head *pages,
 274                                 unsigned *nr_pages)
 275 {
 276         int ret;
 277
 278         cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
 279                  __func__, CIFS_I(inode)->fscache, *nr_pages, inode);
 280         ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
 281                                           pages, nr_pages,
 282                                           cifs_readpage_from_fscache_complete,
 283                                           NULL,
 284                                           mapping_gfp_mask(mapping));
 285         switch (ret) {
 286         case 0: /* read submitted to the cache for all pages */
 287                 cifs_dbg(FYI, "%s: submitted\n", __func__);
 288                 return ret;
 289
 290         case -ENOBUFS:  /* some pages are not cached and can't be */
 291         case -ENODATA:  /* some pages are not cached */
 292                 cifs_dbg(FYI, "%s: no page\n", __func__);
 293                 return 1;
 294
 295         default:
 296                 cifs_dbg(FYI, "unknown error ret = %d\n", ret);
 297         }
 298
 299         return ret;
 300 }
 301
 302 void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
 303 {
 304         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 305         int ret;
 306
 307         cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
 308                  __func__, cifsi->fscache, page, inode);
 309         ret = fscache_write_page(cifsi->fscache, page,
 310                                  cifsi->vfs_inode.i_size, GFP_KERNEL);
 311         if (ret != 0)
 312                 fscache_uncache_page(cifsi->fscache, page);
 313 }
 314
 315 void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
 316 {
 317         cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
 318                  __func__, CIFS_I(inode)->fscache, inode);
 319         fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
 320 }
 321
 322 void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
 323 {
 324         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 325         struct fscache_cookie *cookie = cifsi->fscache;
 326
 327         cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
 328         fscache_wait_on_page_write(cookie, page);
 329         fscache_uncache_page(cookie, page);
 330 }