WebSVN – HelenOS – Diff – /branches/network/uspace/srv/vfs/vfs_node.c



 */
 
#include "vfs.h"
#include <stdlib.h>
#include <string.h>
 
#include <fibril_sync.h>
#include <adt/hash_table.h>
#include <assert.h>
#include <async.h>
#include <errno.h>
 
/** Mutex protecting the VFS node hash table. */
FIBRIL_MUTEX_INITIALIZE(nodes_mutex);
 
#define NODES_BUCKETS_LOG   8
#define NODES_BUCKETS       (1 << NODES_BUCKETS_LOG)
 
/** VFS node hash table containing all active, in-memory VFS nodes. */

 *
 * @param node      VFS node that will have its refcnt incremented.
 */
void vfs_node_addref(vfs_node_t *node)
{
    fibril_mutex_lock(&nodes_mutex);
    _vfs_node_addref(node);
    fibril_mutex_unlock(&nodes_mutex);
}
 
/** Decrement reference count of a VFS node.
 *
 * This function handles the case when the reference count drops to zero.

void vfs_node_delref(vfs_node_t *node)
{
    bool free_vfs_node = false;
    bool free_fs_node = false;
 
    fibril_mutex_lock(&nodes_mutex);
    if (node->refcnt-- == 1) {
        /*
         * We are dropping the last reference to this node.
         * Remove it from the VFS node hash table.
         */

        hash_table_remove(&nodes, key, 3);
        free_vfs_node = true;
        if (!node->lnkcnt)
            free_fs_node = true;
    }
    fibril_mutex_unlock(&nodes_mutex);
 
    if (free_fs_node) {
        /*
         * The node is not visible in the file system namespace.
         * Free up its resources.

        [KEY_INDEX] = result->triplet.index
    };
    link_t *tmp;
    vfs_node_t *node;
 
    fibril_mutex_lock(&nodes_mutex);
    tmp = hash_table_find(&nodes, key);
    if (!tmp) {
        node = (vfs_node_t *) malloc(sizeof(vfs_node_t));
        if (!node) {
            fibril_mutex_unlock(&nodes_mutex);
            return NULL;
        }
        memset(node, 0, sizeof(vfs_node_t));
        node->fs_handle = result->triplet.fs_handle;
        node->dev_handle = result->triplet.dev_handle;
        node->index = result->triplet.index;
        node->size = result->size;
        node->lnkcnt = result->lnkcnt;
        node->type = result->type;
        link_initialize(&node->nh_link);
        fibril_rwlock_initialize(&node->contents_rwlock);
        hash_table_insert(&nodes, key, &node->nh_link);
    } else {
        node = hash_table_get_instance(tmp, vfs_node_t, nh_link);
        if (node->type == VFS_NODE_UNKNOWN &&
            result->type != VFS_NODE_UNKNOWN) {
            /* Upgrade the node type. */
            node->type = result->type;
        }

    assert(node->size == result->size);
    assert(node->lnkcnt == result->lnkcnt);
    assert(node->type == result->type || result->type == VFS_NODE_UNKNOWN);
 
    _vfs_node_addref(node);
    fibril_mutex_unlock(&nodes_mutex);
 
    return node;
}
 
/** Return VFS node when no longer needed by the caller.

{
}
 
/**
 * @}
 */

Rev 4153	Rev 4581
Line 36...	Line 36...
36	*/	36	*/
37		37
38	#include "vfs.h"	38	#include "vfs.h"
39	#include <stdlib.h>	39	#include <stdlib.h>
40	#include <string.h>	40	#include <string.h>
41	#include <futex.h>	-
42	#include <rwlock.h>	41	#include <fibril_sync.h>
43	#include <libadt/hash_table.h>	42	#include <adt/hash_table.h>
44	#include <assert.h>	43	#include <assert.h>
45	#include <async.h>	44	#include <async.h>
46	#include <errno.h>	45	#include <errno.h>
47		46
48	/** Futex protecting the VFS node hash table. */	47	/** Mutex protecting the VFS node hash table. */
49	futex_t nodes_futex = FUTEX_INITIALIZER;	48	FIBRIL_MUTEX_INITIALIZE(nodes_mutex);
50		49
51	#define NODES_BUCKETS_LOG 8	50	#define NODES_BUCKETS_LOG 8
52	#define NODES_BUCKETS (1 << NODES_BUCKETS_LOG)	51	#define NODES_BUCKETS (1 << NODES_BUCKETS_LOG)
53		52
54	/** VFS node hash table containing all active, in-memory VFS nodes. */	53	/** VFS node hash table containing all active, in-memory VFS nodes. */
Line 87...	Line 86...
87	*	86	*
88	* @param node VFS node that will have its refcnt incremented.	87	* @param node VFS node that will have its refcnt incremented.
89	*/	88	*/
90	void vfs_node_addref(vfs_node_t *node)	89	void vfs_node_addref(vfs_node_t *node)
91	{	90	{
92	futex_down(&nodes_futex);	91	fibril_mutex_lock(&nodes_mutex);
93	_vfs_node_addref(node);	92	_vfs_node_addref(node);
94	futex_up(&nodes_futex);	93	fibril_mutex_unlock(&nodes_mutex);
95	}	94	}
96		95
97	/** Decrement reference count of a VFS node.	96	/** Decrement reference count of a VFS node.
98	*	97	*
99	* This function handles the case when the reference count drops to zero.	98	* This function handles the case when the reference count drops to zero.
Line 103...	Line 102...
103	void vfs_node_delref(vfs_node_t *node)	102	void vfs_node_delref(vfs_node_t *node)
104	{	103	{
105	bool free_vfs_node = false;	104	bool free_vfs_node = false;
106	bool free_fs_node = false;	105	bool free_fs_node = false;
107		106
108	futex_down(&nodes_futex);	107	fibril_mutex_lock(&nodes_mutex);
109	if (node->refcnt-- == 1) {	108	if (node->refcnt-- == 1) {
110	/*	109	/*
111	* We are dropping the last reference to this node.	110	* We are dropping the last reference to this node.
112	* Remove it from the VFS node hash table.	111	* Remove it from the VFS node hash table.
113	*/	112	*/
Line 119...	Line 118...
119	hash_table_remove(&nodes, key, 3);	118	hash_table_remove(&nodes, key, 3);
120	free_vfs_node = true;	119	free_vfs_node = true;
121	if (!node->lnkcnt)	120	if (!node->lnkcnt)
122	free_fs_node = true;	121	free_fs_node = true;
123	}	122	}
124	futex_up(&nodes_futex);	123	fibril_mutex_unlock(&nodes_mutex);
125		124
126	if (free_fs_node) {	125	if (free_fs_node) {
127	/*	126	/*
128	* The node is not visible in the file system namespace.	127	* The node is not visible in the file system namespace.
129	* Free up its resources.	128	* Free up its resources.
Line 159...	Line 158...
159	[KEY_INDEX] = result->triplet.index	158	[KEY_INDEX] = result->triplet.index
160	};	159	};
161	link_t *tmp;	160	link_t *tmp;
162	vfs_node_t *node;	161	vfs_node_t *node;
163		162
164	futex_down(&nodes_futex);	163	fibril_mutex_lock(&nodes_mutex);
165	tmp = hash_table_find(&nodes, key);	164	tmp = hash_table_find(&nodes, key);
166	if (!tmp) {	165	if (!tmp) {
167	node = (vfs_node_t *) malloc(sizeof(vfs_node_t));	166	node = (vfs_node_t *) malloc(sizeof(vfs_node_t));
168	if (!node) {	167	if (!node) {
169	futex_up(&nodes_futex);	168	fibril_mutex_unlock(&nodes_mutex);
170	return NULL;	169	return NULL;
171	}	170	}
172	memset(node, 0, sizeof(vfs_node_t));	171	memset(node, 0, sizeof(vfs_node_t));
173	node->fs_handle = result->triplet.fs_handle;	172	node->fs_handle = result->triplet.fs_handle;
174	node->dev_handle = result->triplet.dev_handle;	173	node->dev_handle = result->triplet.dev_handle;
175	node->index = result->triplet.index;	174	node->index = result->triplet.index;
176	node->size = result->size;	175	node->size = result->size;
177	node->lnkcnt = result->lnkcnt;	176	node->lnkcnt = result->lnkcnt;
178	node->type = result->type;	177	node->type = result->type;
179	link_initialize(&node->nh_link);	178	link_initialize(&node->nh_link);
180	rwlock_initialize(&node->contents_rwlock);	179	fibril_rwlock_initialize(&node->contents_rwlock);
181	hash_table_insert(&nodes, key, &node->nh_link);	180	hash_table_insert(&nodes, key, &node->nh_link);
182	} else {	181	} else {
183	node = hash_table_get_instance(tmp, vfs_node_t, nh_link);	182	node = hash_table_get_instance(tmp, vfs_node_t, nh_link);
184	if (node->type == VFS_NODE_UNKNOWN &&	183	if (node->type == VFS_NODE_UNKNOWN &&
185	result->type != VFS_NODE_UNKNOWN) {	184	result->type != VFS_NODE_UNKNOWN) {
186	/* Upgrade the node type. */	185	/* Upgrade the node type. */
187	node->type = result->type;	186	node->type = result->type;
188	}	187	}
Line 191...	Line 190...
191	assert(node->size == result->size);	190	assert(node->size == result->size);
192	assert(node->lnkcnt == result->lnkcnt);	191	assert(node->lnkcnt == result->lnkcnt);
193	assert(node->type == result->type \|\| result->type == VFS_NODE_UNKNOWN);	192	assert(node->type == result->type \|\| result->type == VFS_NODE_UNKNOWN);
194		193
195	_vfs_node_addref(node);	194	_vfs_node_addref(node);
196	futex_up(&nodes_futex);	195	fibril_mutex_unlock(&nodes_mutex);
197		196
198	return node;	197	return node;
199	}	198	}
200		199
201	/** Return VFS node when no longer needed by the caller.	200	/** Return VFS node when no longer needed by the caller.
Line 231...	Line 230...
231	{	230	{
232	}	231	}
233		232
234	/**	233	/**
235	* @}	234	* @}
236	*/	235	*/

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(root)/branches/network/uspace/srv/vfs/vfs_node.c – Rev 4153 → 4581