diff options
Diffstat (limited to 'include/linux/fs.h')
-rw-r--r-- | include/linux/fs.h | 114 |
1 files changed, 1 insertions, 113 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index aa74f7de9dcd..58ce336d4a6b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h | |||
@@ -289,6 +289,7 @@ extern int dir_notify_enable; | |||
289 | #include <asm/semaphore.h> | 289 | #include <asm/semaphore.h> |
290 | #include <asm/byteorder.h> | 290 | #include <asm/byteorder.h> |
291 | 291 | ||
292 | struct export_operations; | ||
292 | struct hd_geometry; | 293 | struct hd_geometry; |
293 | struct iovec; | 294 | struct iovec; |
294 | struct nameidata; | 295 | struct nameidata; |
@@ -1278,119 +1279,6 @@ static inline void file_accessed(struct file *file) | |||
1278 | 1279 | ||
1279 | int sync_inode(struct inode *inode, struct writeback_control *wbc); | 1280 | int sync_inode(struct inode *inode, struct writeback_control *wbc); |
1280 | 1281 | ||
1281 | /** | ||
1282 | * struct export_operations - for nfsd to communicate with file systems | ||
1283 | * @decode_fh: decode a file handle fragment and return a &struct dentry | ||
1284 | * @encode_fh: encode a file handle fragment from a dentry | ||
1285 | * @get_name: find the name for a given inode in a given directory | ||
1286 | * @get_parent: find the parent of a given directory | ||
1287 | * @get_dentry: find a dentry for the inode given a file handle sub-fragment | ||
1288 | * @find_exported_dentry: | ||
1289 | * set by the exporting module to a standard helper function. | ||
1290 | * | ||
1291 | * Description: | ||
1292 | * The export_operations structure provides a means for nfsd to communicate | ||
1293 | * with a particular exported file system - particularly enabling nfsd and | ||
1294 | * the filesystem to co-operate when dealing with file handles. | ||
1295 | * | ||
1296 | * export_operations contains two basic operation for dealing with file | ||
1297 | * handles, decode_fh() and encode_fh(), and allows for some other | ||
1298 | * operations to be defined which standard helper routines use to get | ||
1299 | * specific information from the filesystem. | ||
1300 | * | ||
1301 | * nfsd encodes information use to determine which filesystem a filehandle | ||
1302 | * applies to in the initial part of the file handle. The remainder, termed | ||
1303 | * a file handle fragment, is controlled completely by the filesystem. The | ||
1304 | * standard helper routines assume that this fragment will contain one or | ||
1305 | * two sub-fragments, one which identifies the file, and one which may be | ||
1306 | * used to identify the (a) directory containing the file. | ||
1307 | * | ||
1308 | * In some situations, nfsd needs to get a dentry which is connected into a | ||
1309 | * specific part of the file tree. To allow for this, it passes the | ||
1310 | * function acceptable() together with a @context which can be used to see | ||
1311 | * if the dentry is acceptable. As there can be multiple dentrys for a | ||
1312 | * given file, the filesystem should check each one for acceptability before | ||
1313 | * looking for the next. As soon as an acceptable one is found, it should | ||
1314 | * be returned. | ||
1315 | * | ||
1316 | * decode_fh: | ||
1317 | * @decode_fh is given a &struct super_block (@sb), a file handle fragment | ||
1318 | * (@fh, @fh_len) and an acceptability testing function (@acceptable, | ||
1319 | * @context). It should return a &struct dentry which refers to the same | ||
1320 | * file that the file handle fragment refers to, and which passes the | ||
1321 | * acceptability test. If it cannot, it should return a %NULL pointer if | ||
1322 | * the file was found but no acceptable &dentries were available, or a | ||
1323 | * %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or | ||
1324 | * %ENOMEM). | ||
1325 | * | ||
1326 | * encode_fh: | ||
1327 | * @encode_fh should store in the file handle fragment @fh (using at most | ||
1328 | * @max_len bytes) information that can be used by @decode_fh to recover the | ||
1329 | * file refered to by the &struct dentry @de. If the @connectable flag is | ||
1330 | * set, the encode_fh() should store sufficient information so that a good | ||
1331 | * attempt can be made to find not only the file but also it's place in the | ||
1332 | * filesystem. This typically means storing a reference to de->d_parent in | ||
1333 | * the filehandle fragment. encode_fh() should return the number of bytes | ||
1334 | * stored or a negative error code such as %-ENOSPC | ||
1335 | * | ||
1336 | * get_name: | ||
1337 | * @get_name should find a name for the given @child in the given @parent | ||
1338 | * directory. The name should be stored in the @name (with the | ||
1339 | * understanding that it is already pointing to a a %NAME_MAX+1 sized | ||
1340 | * buffer. get_name() should return %0 on success, a negative error code | ||
1341 | * or error. @get_name will be called without @parent->i_mutex held. | ||
1342 | * | ||
1343 | * get_parent: | ||
1344 | * @get_parent should find the parent directory for the given @child which | ||
1345 | * is also a directory. In the event that it cannot be found, or storage | ||
1346 | * space cannot be allocated, a %ERR_PTR should be returned. | ||
1347 | * | ||
1348 | * get_dentry: | ||
1349 | * Given a &super_block (@sb) and a pointer to a file-system specific inode | ||
1350 | * identifier, possibly an inode number, (@inump) get_dentry() should find | ||
1351 | * the identified inode and return a dentry for that inode. Any suitable | ||
1352 | * dentry can be returned including, if necessary, a new dentry created with | ||
1353 | * d_alloc_root. The caller can then find any other extant dentrys by | ||
1354 | * following the d_alias links. If a new dentry was created using | ||
1355 | * d_alloc_root, DCACHE_NFSD_DISCONNECTED should be set, and the dentry | ||
1356 | * should be d_rehash()ed. | ||
1357 | * | ||
1358 | * If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code | ||
1359 | * can be returned. The @inump will be whatever was passed to | ||
1360 | * nfsd_find_fh_dentry() in either the @obj or @parent parameters. | ||
1361 | * | ||
1362 | * Locking rules: | ||
1363 | * get_parent is called with child->d_inode->i_mutex down | ||
1364 | * get_name is not (which is possibly inconsistent) | ||
1365 | */ | ||
1366 | |||
1367 | struct export_operations { | ||
1368 | struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh, int fh_len, int fh_type, | ||
1369 | int (*acceptable)(void *context, struct dentry *de), | ||
1370 | void *context); | ||
1371 | int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len, | ||
1372 | int connectable); | ||
1373 | |||
1374 | /* the following are only called from the filesystem itself */ | ||
1375 | int (*get_name)(struct dentry *parent, char *name, | ||
1376 | struct dentry *child); | ||
1377 | struct dentry * (*get_parent)(struct dentry *child); | ||
1378 | struct dentry * (*get_dentry)(struct super_block *sb, void *inump); | ||
1379 | |||
1380 | /* This is set by the exporting module to a standard helper */ | ||
1381 | struct dentry * (*find_exported_dentry)( | ||
1382 | struct super_block *sb, void *obj, void *parent, | ||
1383 | int (*acceptable)(void *context, struct dentry *de), | ||
1384 | void *context); | ||
1385 | |||
1386 | |||
1387 | }; | ||
1388 | |||
1389 | extern struct dentry * | ||
1390 | find_exported_dentry(struct super_block *sb, void *obj, void *parent, | ||
1391 | int (*acceptable)(void *context, struct dentry *de), | ||
1392 | void *context); | ||
1393 | |||
1394 | struct file_system_type { | 1282 | struct file_system_type { |
1395 | const char *name; | 1283 | const char *name; |
1396 | int fs_flags; | 1284 | int fs_flags; |