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_sec = cifsi->vfs_inode.i_mtime.tv_sec;
 133         auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
 134         auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
 135         auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
 136
 137         cifsi->fscache =
 138                 fscache_acquire_cookie(tcon->fscache,
 139                                        &cifs_fscache_inode_object_def,
 140                                        &cifsi->uniqueid, sizeof(cifsi->uniqueid),
 141                                        &auxdata, sizeof(auxdata),
 142                                        cifsi, cifsi->vfs_inode.i_size, true);
 143 }
 144
 145 static void cifs_fscache_enable_inode_cookie(struct inode *inode)
 146 {
 147         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 148         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 149         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 150
 151         if (cifsi->fscache)
 152                 return;
 153
 154         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE))
 155                 return;
 156
 157         cifs_fscache_acquire_inode_cookie(cifsi, tcon);
 158
 159         cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
 160                  __func__, tcon->fscache, cifsi->fscache);
 161 }
 162
 163 void cifs_fscache_release_inode_cookie(struct inode *inode)
 164 {
 165         struct cifs_fscache_inode_auxdata auxdata;
 166         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 167
 168         if (cifsi->fscache) {
 169                 memset(&auxdata, 0, sizeof(auxdata));
 170                 auxdata.eof = cifsi->server_eof;
 171                 auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
 172                 auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
 173                 auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
 174                 auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
 175
 176                 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
 177                 fscache_relinquish_cookie(cifsi->fscache, &auxdata, false);
 178                 cifsi->fscache = NULL;
 179         }
 180 }
 181
 182 static void cifs_fscache_disable_inode_cookie(struct inode *inode)
 183 {
 184         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 185
 186         if (cifsi->fscache) {
 187                 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
 188                 fscache_uncache_all_inode_pages(cifsi->fscache, inode);
 189                 fscache_relinquish_cookie(cifsi->fscache, NULL, true);
 190                 cifsi->fscache = NULL;
 191         }
 192 }
 193
 194 void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
 195 {
 196         if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
 197                 cifs_fscache_disable_inode_cookie(inode);
 198         else
 199                 cifs_fscache_enable_inode_cookie(inode);
 200 }
 201
 202 void cifs_fscache_reset_inode_cookie(struct inode *inode)
 203 {
 204         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 205         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 206         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 207         struct fscache_cookie *old = cifsi->fscache;
 208
 209         if (cifsi->fscache) {
 210                 /* retire the current fscache cache and get a new one */
 211                 fscache_relinquish_cookie(cifsi->fscache, NULL, true);
 212
 213                 cifs_fscache_acquire_inode_cookie(cifsi, tcon);
 214                 cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
 215                          __func__, cifsi->fscache, old);
 216         }
 217 }
 218
 219 int cifs_fscache_release_page(struct page *page, gfp_t gfp)
 220 {
 221         if (PageFsCache(page)) {
 222                 struct inode *inode = page->mapping->host;
 223                 struct cifsInodeInfo *cifsi = CIFS_I(inode);
 224
 225                 cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
 226                          __func__, page, cifsi->fscache);
 227                 if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
 228                         return 0;
 229         }
 230
 231         return 1;
 232 }
 233
 234 static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
 235                                                 int error)
 236 {
 237         cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, page, error);
 238         if (!error)
 239                 SetPageUptodate(page);
 240         unlock_page(page);
 241 }
 242
 243 /*
 244  * Retrieve a page from FS-Cache
 245  */
 246 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 247 {
 248         int ret;
 249
 250         cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
 251                  __func__, CIFS_I(inode)->fscache, page, inode);
 252         ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
 253                                          cifs_readpage_from_fscache_complete,
 254                                          NULL,
 255                                          GFP_KERNEL);
 256         switch (ret) {
 257
 258         case 0: /* page found in fscache, read submitted */
 259                 cifs_dbg(FYI, "%s: submitted\n", __func__);
 260                 return ret;
 261         case -ENOBUFS:  /* page won't be cached */
 262         case -ENODATA:  /* page not in cache */
 263                 cifs_dbg(FYI, "%s: %d\n", __func__, ret);
 264                 return 1;
 265
 266         default:
 267                 cifs_dbg(VFS, "unknown error ret = %d\n", ret);
 268         }
 269         return ret;
 270 }
 271
 272 /*
 273  * Retrieve a set of pages from FS-Cache
 274  */
 275 int __cifs_readpages_from_fscache(struct inode *inode,
 276                                 struct address_space *mapping,
 277                                 struct list_head *pages,
 278                                 unsigned *nr_pages)
 279 {
 280         int ret;
 281
 282         cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
 283                  __func__, CIFS_I(inode)->fscache, *nr_pages, inode);
 284         ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
 285                                           pages, nr_pages,
 286                                           cifs_readpage_from_fscache_complete,
 287                                           NULL,
 288                                           mapping_gfp_mask(mapping));
 289         switch (ret) {
 290         case 0: /* read submitted to the cache for all pages */
 291                 cifs_dbg(FYI, "%s: submitted\n", __func__);
 292                 return ret;
 293
 294         case -ENOBUFS:  /* some pages are not cached and can't be */
 295         case -ENODATA:  /* some pages are not cached */
 296                 cifs_dbg(FYI, "%s: no page\n", __func__);
 297                 return 1;
 298
 299         default:
 300                 cifs_dbg(FYI, "unknown error ret = %d\n", ret);
 301         }
 302
 303         return ret;
 304 }
 305
 306 void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
 307 {
 308         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 309         int ret;
 310
 311         cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
 312                  __func__, cifsi->fscache, page, inode);
 313         ret = fscache_write_page(cifsi->fscache, page,
 314                                  cifsi->vfs_inode.i_size, GFP_KERNEL);
 315         if (ret != 0)
 316                 fscache_uncache_page(cifsi->fscache, page);
 317 }
 318
 319 void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
 320 {
 321         cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
 322                  __func__, CIFS_I(inode)->fscache, inode);
 323         fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
 324 }
 325
 326 void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
 327 {
 328         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 329         struct fscache_cookie *cookie = cifsi->fscache;
 330
 331         cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
 332         fscache_wait_on_page_write(cookie, page);
 333         fscache_uncache_page(cookie, page);
 334 }