/* Hurd unionfs Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc. Written by Moritz Schulte . This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ /* Underlying filesystem management. */ #ifndef INCLUDED_ULFS_H #define INCLUDED_ULFS_H /* The structure for each registered underlying filesystem. */ typedef struct ulfs { char *path; int flags; int priority; struct ulfs *next, *prev; } ulfs_t; /* Flags. */ /* The according ulfs is marked writable. */ #define FLAG_ULFS_WRITABLE 0x00000001 /* The start of the ulfs chain. */ extern ulfs_t *ulfs_chain_start; /* The end of the ulfs chain, we need this, to go through the chain in reversed order. */ extern ulfs_t *ulfs_chain_end; /* Number of registered underlying filesystems. */ extern unsigned int ulfs_num; /* The lock protecting the ulfs data structures. */ extern struct mutex ulfs_lock; /* Register a new underlying filesystem. */ error_t ulfs_register (char *path, int flags, int priority); /* Unregister an underlying filesystem. */ error_t ulfs_unregister (char *path); /* Get an ULFS element by it's index. */ error_t ulfs_get_num (int num, ulfs_t **ulfs); /* Removes invalid ulfs entries. */ void ulfs_check (void); #define ulfs_iterate \ for (ulfs_t *ulfs = (mutex_lock (&ulfs_lock), \ ulfs_chain_start); \ ulfs || (mutex_unlock (&ulfs_lock), 0); \ ulfs = ulfs->next) #define ulfs_iterate_unlocked \ for (ulfs_t *ulfs = ulfs_chain_start; \ ulfs; \ ulfs = ulfs->next) #endif