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Diffstat (limited to 'libtreefs/treefs.h')
| -rw-r--r-- | libtreefs/treefs.h | 493 |
1 files changed, 0 insertions, 493 deletions
diff --git a/libtreefs/treefs.h b/libtreefs/treefs.h deleted file mode 100644 index 50cf91fe..00000000 --- a/libtreefs/treefs.h +++ /dev/null @@ -1,493 +0,0 @@ -/* Hierarchial filesystem support - - Copyright (C) 1995, 2002 Free Software Foundation, Inc. - - Written by Miles Bader <miles@gnu.org> - - This file is part of the GNU Hurd. - - The GNU Hurd 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, or (at - your option) any later version. - - The GNU Hurd 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ - -#ifndef __TREEFS_H__ -#define __TREEFS_H__ - -#include <errno.h> -#include <pthread.h> -#include <assert-backtrace.h> -#include <features.h> - -#include <sys/stat.h> - -#include <hurd/hurd_types.h> -#include <hurd/ports.h> -#include <hurd/fshelp.h> - -/* Include the hook calling macros and non-rpc hook definitions (to get - those, include "trees-s-hooks.h"). */ -#include "treefs-hooks.h" - -#ifdef TREEFS_DEFINE_EI -#define TREEFS_EI -#else -#define TREEFS_EI __extern_inline -#endif - -/* ---------------------------------------------------------------- */ - -typedef void (**treefs_hook_vector_t)(); - -/* A list of nodes. */ -struct treefs_node_list; - -/* Each user port referring to a file points to one of these. */ -struct treefs_handle -{ - struct port_info pi; - struct treefs_auth *auth; /* User identification */ - struct treefs_peropen *po; /* The io object itself */ - void *u; /* for user use */ -}; - -/* An authentication cookie. */ -struct treefs_auth -{ - int refs; - uid_t *uids, *gids; - int nuids, ngids; - int isroot; - void *u; /* for user use */ -}; - -/* Bits the user is permitted to set with io_*_openmodes */ -#define TREEFS_SETTABLE_FLAGS (O_APPEND|O_ASYNC|O_FSYNC|O_NONBLOCK|O_NOATIME) - -/* Bits that are turned off after open */ -#define TREEFS_OPENONLY_FLAGS (O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS|O_NONBLOCK) - -struct treefs_peropen -{ - int refs; - int open_flags; - int user_lock_state; - - /* A port to the directory through which this open file was reached. */ - mach_port_t parent_port; - - void *u; /* for user use */ - - struct treefs_node *node; -}; - -/* A filesystem node in the tree. */ -struct treefs_node -{ - io_statbuf_t stat; - struct treefs_fsys *fsys; - - struct trans_link active_trans; - char *passive_trans; - struct lock_box user_lock; - - pthread_mutex_t lock; - unsigned refs, weak_refs; - - /* Node ops */ - treefs_hook_vector_t hooks; - - /* If this node is a directory, then this is the directory state. */ - struct treefs_node_list *children; - - void *u; /* for user use */ -}; - -struct treefs_node_list -{ - struct treefs_node **nodes; - unsigned short num_nodes, nodes_alloced; - char *names; - unsigned short names_len, names_alloced; -}; - -struct treefs_fsys -{ - struct port_info pi; - pthread_mutex_t lock; - - /* The root node in this filesystem. */ - struct treefs_node *root; - - /* The port for the node which this filesystem is translating. */ - mach_port_t underlying_port; - /* And stat info for it. */ - io_statbuf_t underlying_stat; - - /* Flags from the TREEFS_FSYS_ set. */ - int flags; - /* Max number of symlink expansions allowed. */ - unsigned max_symlinks; - /* Sync interval (in seconds). 0 means all operations should be - synchronous, any negative value means never sync. */ - int sync_interval; - - /* Values to return from a statfs. */ - int fs_type; - int fs_id; - - /* This is the hook vector that each new node in this filesystem starts out - with. */ - treefs_hook_vector_t hooks; - - /* The port bucket to which all of our ports belongs. */ - struct ports_bucket *port_bucket; - - /* Various classes of ports we know about. */ - struct port_class *handle_port_class; - - void *u; /* for user use */ -}; - -/* Filesystem flags. */ -#define TREEFS_FSYS_READONLY 0x1 - -/* ---------------------------------------------------------------- */ -/* In-core directory management routines (`mdir' == `memory dir'). These are - intended for keeping non-permanent directory state. If called on a - non-dir, ENOTDIR is returned. */ - -/* Add CHILD to DIR as NAME, replacing any existing entry. If OLD_CHILD is - NULL, and NAME already exists in dir, EEXIST is returned, otherwise, any - previous child is replaced and returned in OLD_CHILD. DIR should be - locked. */ -error_t treefs_mdir_add (struct treefs_node *dir, char *name, - struct treefs_node *child, - struct treefs_node **old_child); - -/* Remove any entry in DIR called NAME. If there is no such entry, ENOENT is - returned. If OLD_CHILD is non-NULL, any removed entry is returned in it. - DIR should be locked. */ -error_t treefs_mdir_remove (struct treefs_node *dir, char *name, - struct treefs_node **old_child); - -/* Returns in NODE any entry called NAME in DIR, or NULL (and ENOENT) if - there isn't such. DIR should be locked. */ -error_t treefs_mdir_get (struct treefs_node *dir, char *name, - struct treefs_node **node); - -/* Call FUN on each child of DIR; if FUN returns a non-zero value at any - point, stop iterating and return that value immediately. */ -error_t treefs_mdir_for_each (struct treefs_node *dir, - error_t (*fun)(struct treefs_node *node)); - -/* ---------------------------------------------------------------- */ -/* Functions for dealing with node lists. */ - -/* Return a new node list, or NULL if a memory allocation error occurs. */ -struct treefs_node_list *treefs_make_node_list (); - -/* Add NODE to LIST as NAME, replacing any existing entry. If OLD_NODE is - NULL, and an entry NAME already exists, EEXIST is returned, otherwise, any - previous child is replaced and returned in OLD_NODE. */ -error_t treefs_node_list_add (struct treefs_node_list *list, char *name, - struct treefs_node *node, - struct treefs_node **old_node); - -/* Remove any entry in LIST called NAME. If there is no such entry, ENOENT is - returned. If OLD_NODE is non-NULL, any removed entry is returned in it. */ -error_t treefs_node_list_remove (struct treefs_node_list *list, char *name, - struct treefs_node **old_node); - -/* Returns in NODE any entry called NAME in LIST, or NULL (and ENOENT) if - there isn't such. */ -error_t treefs_node_list_get (struct treefs_node_list *list, char *name, - struct treefs_node **node); - -/* Call FUN on each node in LIST; if FUN returns a non-zero value at any - point, stop iterating and return that value immediately. */ -error_t treefs_node_list_for_each (struct treefs_node_list *list, - error_t (*fun)(char *name, - struct treefs_node *node)); - -/* ---------------------------------------------------------------- */ -/* Functions for manipulating hook vectors. */ - -typedef void (*treefs_hook_vector_init_t[TREEFS_NUM_HOOKS])(); - -extern treefs_hook_vector_init_t treefs_default_hooks; - -/* Returns a copy of the treefs hook vector HOOKS, or a zero'd vector if HOOKS - is NULL. If HOOKS is NULL, treefs_default_hooks is used. If a memory - allocation error occurs, NULL is returned. */ -treefs_hook_vector_t treefs_hooks_clone (treefs_hook_vector_t hooks); - -/* Copies each non-NULL entry in OVERRIDES into HOOKS. */ -void treefs_hooks_override (treefs_hook_vector_t hooks, - treefs_hook_vector_t overrides); - -/* Sets the hook NUM in HOOKS to HOOK. */ -void treefs_hooks_set (treefs_hook_vector_t hooks, - unsigned num, void (*hook)()); - -/* ---------------------------------------------------------------- */ -/* Reference counting function (largely stolen from diskfs). */ - -extern pthread_spinlock_t treefs_node_refcnt_lock; - -extern void treefs_node_ref (struct treefs_node *node); -extern void treefs_node_release (struct treefs_node *node); -extern void treefs_node_unref (struct treefs_node *node); -extern void treefs_node_ref_weak (struct treefs_node *node); -extern void treefs_node_release_weak (struct treefs_node *node); -extern void treefs_node_unref_weak (struct treefs_node *node); - -#if defined(__USE_EXTERN_INLINES) || defined(TREEFS_DEFINE_EI) -/* Add a hard reference to a node. If there were no hard - references previously, then the node cannot be locked - (because you must hold a hard reference to hold the lock). */ -TREEFS_EI void -treefs_node_ref (struct treefs_node *node) -{ - int new_ref; - pthread_spin_lock (&treefs_node_refcnt_lock); - node->refs++; - new_ref = (node->refs == 1); - pthread_spin_unlock (&treefs_node_refcnt_lock); - if (new_ref) - { - pthread_mutex_lock (&node->lock); - treefs_node_new_refs (node); - pthread_mutex_unlock (&node->lock); - } -} - -/* Unlock node NODE and release a hard reference; if this is the last - hard reference and there are no links to the file then request - weak references to be dropped. */ -TREEFS_EI void -treefs_node_release (struct treefs_node *node) -{ - int tried_drop_weak_refs = 0; - - loop: - pthread_spin_lock (&treefs_node_refcnt_lock); - assert_backtrace (node->refs); - node->refs--; - if (node->refs + node->weak_refs == 0) - treefs_node_drop (node); - else if (node->refs == 0 && !tried_drop_weak_refs) - { - pthread_spin_unlock (&treefs_node_refcnt_lock); - treefs_node_lost_refs (node); - if (treefs_node_unlinked (node)) - { - /* There are no links. If there are weak references that - can be dropped, we can't let them postpone deallocation. - So attempt to drop them. But that's a user-supplied - routine, which might result in further recursive calls to - the ref-counting system. So we have to reacquire our - reference around the call to forestall disaster. */ - pthread_spin_unlock (&treefs_node_refcnt_lock); - node->refs++; - pthread_spin_unlock (&treefs_node_refcnt_lock); - - treefs_node_try_dropping_weak_refs (node); - - /* But there's no value in looping forever in this - routine; only try to drop weak references once. */ - tried_drop_weak_refs = 1; - - /* Now we can drop the reference back... */ - goto loop; - } - } - else - pthread_spin_unlock (&treefs_node_refcnt_lock); - pthread_mutex_unlock (&node->lock); -} - -/* Release a hard reference on NODE. If NODE is locked by anyone, then - this cannot be the last hard reference (because you must hold a - hard reference in order to hold the lock). If this is the last - hard reference and there are no links, then request weak references - to be dropped. */ -TREEFS_EI void -treefs_node_unref (struct treefs_node *node) -{ - int tried_drop_weak_refs = 0; - - loop: - pthread_spin_lock (&treefs_node_refcnt_lock); - assert_backtrace (node->refs); - node->refs--; - if (node->refs + node->weak_refs == 0) - { - pthread_mutex_lock (&node->lock); - treefs_node_drop (node); - } - else if (node->refs == 0) - { - pthread_mutex_lock (&node->lock); - pthread_spin_unlock (&treefs_node_refcnt_lock); - treefs_node_lost_refs (node); - if (treefs_node_unlinked(node) && !tried_drop_weak_refs) - { - /* Same issue here as in nodeut; see that for explanation */ - pthread_spin_unlock (&treefs_node_refcnt_lock); - node->refs++; - pthread_spin_unlock (&treefs_node_refcnt_lock); - - treefs_node_try_dropping_weak_refs (node); - tried_drop_weak_refs = 1; - - /* Now we can drop the reference back... */ - pthread_mutex_unlock (&node->lock); - goto loop; - } - pthread_mutex_unlock (&node->lock); - } - else - pthread_spin_unlock (&treefs_node_refcnt_lock); -} - -/* Add a weak reference to a node. */ -TREEFS_EI void -treefs_node_ref_weak (struct treefs_node *node) -{ - pthread_spin_lock (&treefs_node_refcnt_lock); - node->weak_refs++; - pthread_spin_unlock (&treefs_node_refcnt_lock); -} - -/* Unlock node NODE and release a weak reference */ -TREEFS_EI void -treefs_node_release_weak (struct treefs_node *node) -{ - pthread_spin_lock (&treefs_node_refcnt_lock); - assert_backtrace (node->weak_refs); - node->weak_refs--; - if (node->refs + node->weak_refs == 0) - treefs_node_drop (node); - else - { - pthread_spin_unlock (&treefs_node_refcnt_lock); - pthread_mutex_unlock (&node->lock); - } -} - -/* Release a weak reference on NODE. If NODE is locked by anyone, then - this cannot be the last reference (because you must hold a - hard reference in order to hold the lock). */ -TREEFS_EI void -treefs_node_unref_weak (struct treefs_node *node) -{ - pthread_spin_lock (&treefs_node_refcnt_lock); - assert_backtrace (node->weak_refs); - node->weak_refs--; - if (node->refs + node->weak_refs == 0) - { - pthread_mutex_lock (&node->lock); - treefs_node_drop (node); - } - else - pthread_spin_unlock (&treefs_node_refcnt_lock); -} -#endif /* Use extern inlines. */ - -/* ---------------------------------------------------------------- */ - -/* Return in PORT a send right for a new handle, pointing at the peropen PO, - with rights initialized from AUTH. */ -error_t -treefs_peropen_create_right (struct treefs_peropen *po, - struct treefs_auth *auth, - mach_port_t *port); - -/* Return a send right for a new handle and a new peropen, pointing at NODE, - with rights initialized from AUTH. MODE and PARENT_PORT are used to - initialize the corresponding fields in the new peropen. */ -error_t -treefs_node_create_right (struct treefs_node *node, int flags, - mach_port_t parent_port, struct treefs_auth *auth, - mach_port_t *port); - -/* ---------------------------------------------------------------- */ -/* Auth functions; copied from diskfs. */ - -extern int treefs_auth_has_uid (struct treefs_auth *auth, uid_t uid); -extern int treefs_auth_in_group (struct treefs_auth *auth, gid_t gid); - -#if defined(__USE_EXTERN_INLINES) || defined(TREEFS_DEFINE_EI) -/* Return nonzero iff the user identified by AUTH has uid UID. */ -TREEFS_EI int -treefs_auth_has_uid (struct treefs_auth *auth, uid_t uid) -{ - int i; - for (i = 0; i < auth->nuids; i++) - if (auth->uids[i] == uid) - return 1; - return 0; -} - -/* Return nonzero iff the user identified by AUTH has group GID. */ -TREEFS_EI int -treefs_auth_in_group (struct treefs_auth *auth, gid_t gid) -{ - int i; - for (i = 0; i < auth->ngids; i++) - if (auth->gids[i] == gid) - return 1; - return 0; -} -#endif /* Use extern inlines. */ - -/* ---------------------------------------------------------------- */ -/* Helper routines for dealing with translators. */ - -/* Return the active translator control port for NODE. If there is no - translator, active or passive, MACH_PORT_NULL is returned in CONTROL_PORT. - If there is a translator, it is started if necessary, and returned in - CONTROL_PORT. *DIR_PORT should be a port right to use as the new - translators parent directory. If it is MACH_PORT_NULL, a port is created - from DIR and PARENT_PORT and stored in *DIR_PORT; otherwise DIR and - PARENT_PORT are not used. Neither NODE or DIR should be locked when - calling this function. */ -error_t treefs_node_get_active_trans (struct treefs_node *node, - struct treefs_node *dir, - mach_port_t parent_port, - mach_port_t *control_port, - mach_port_t *dir_port); - -/* Drop the active translator CONTROL_PORT on NODE, unless it's no longer the - current active translator, in which case just drop a reference to it. */ -void treefs_node_drop_active_trans (struct treefs_node *node, - mach_port_t control_port); - -/* ---------------------------------------------------------------- */ -/* Basic node creation. */ - -/* Create a basic node, with one reference and no user-specific fields - initialized, and return it in NODE */ -error_t -treefs_create_node (struct treefs_fsys *fsys, struct treefs_node **node); - -/* Immediately destroy NODE, with no user-finalization. */ -error_t treefs_free_node (struct treefs_node *node); - -/* ---------------------------------------------------------------- */ -/* Some global variables. */ - -/* The port class used by treefs to make filesystem control ports. */ -struct port_class *treefs_fsys_port_class; - -#endif /* __TREEFS_H__ */ |