WebSVN – HelenOS – Diff – /tags/0.3.0/uspace/srv/fs/tmpfs/tmpfs_ops.c


/*
 * Copyright (c) 2008 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup fs
 * @{
 */
 
/**
 * @file    tmpfs_ops.c
 * @brief   Implementation of VFS operations for the TMPFS file system
 *      server.
 */
 
#include "tmpfs.h"
#include "../../vfs/vfs.h"
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <atomic.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <sys/types.h>
#include <libadt/hash_table.h>
#include <as.h>
#include <libfs.h>
 
#define min(a, b)       ((a) < (b) ? (a) : (b))
#define max(a, b)       ((a) > (b) ? (a) : (b))
 
#define DENTRIES_BUCKETS    256
 
#define NAMES_BUCKETS       4
 
/*
 * For now, we don't distinguish between different dev_handles/instances. All
 * requests resolve to the only instance, rooted in the following variable.
 */
static tmpfs_dentry_t *root;
 
/*
 * Implementation of the libfs interface.
 */
 
/* Forward declarations of static functions. */
static bool tmpfs_match(void *, void *, const char *);
static void *tmpfs_node_get(fs_handle_t, dev_handle_t, fs_index_t);
static void *tmpfs_create_node(int);
static bool tmpfs_link_node(void *, void *, const char *);
static int tmpfs_unlink_node(void *, void *);
static void tmpfs_destroy_node(void *);
 
/* Implementation of helper functions. */
static fs_index_t tmpfs_index_get(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->index;
}
 
static size_t tmpfs_size_get(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->size;
}
 
static unsigned tmpfs_lnkcnt_get(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->lnkcnt;
}
 
static void *tmpfs_child_get(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->child;
}
 
static void *tmpfs_sibling_get(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->sibling;
}
 
static void *tmpfs_root_get(void)
{
    return root;
}
 
static char tmpfs_plb_get_char(unsigned pos)
{
    return tmpfs_reg.plb_ro[pos % PLB_SIZE];
}
 
static bool tmpfs_is_directory(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
}
 
static bool tmpfs_is_file(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
}
 
/** libfs operations */
libfs_ops_t tmpfs_libfs_ops = {
    .match = tmpfs_match,
    .node_get = tmpfs_node_get,
    .create = tmpfs_create_node,
    .destroy = tmpfs_destroy_node,
    .link = tmpfs_link_node,
    .unlink = tmpfs_unlink_node,
    .index_get = tmpfs_index_get,
    .size_get = tmpfs_size_get,
    .lnkcnt_get = tmpfs_lnkcnt_get,
    .child_get = tmpfs_child_get,
    .sibling_get = tmpfs_sibling_get,
    .root_get = tmpfs_root_get,
    .plb_get_char = tmpfs_plb_get_char,
    .is_directory = tmpfs_is_directory,
    .is_file = tmpfs_is_file
};
 
/** Hash table of all directory entries. */
hash_table_t dentries;
 
/* Implementation of hash table interface for the dentries hash table. */
static hash_index_t dentries_hash(unsigned long *key)
{
    return *key % DENTRIES_BUCKETS;
}
 
static int dentries_compare(unsigned long *key, hash_count_t keys,
    link_t *item)
{
    tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
        dh_link);
    return dentry->index == *key;
}
 
static void dentries_remove_callback(link_t *item)
{
}
 
/** TMPFS dentries hash table operations. */
hash_table_operations_t dentries_ops = {
    .hash = dentries_hash,
    .compare = dentries_compare,
    .remove_callback = dentries_remove_callback
};
 
fs_index_t tmpfs_next_index = 1;
 
typedef struct {
    char *name;
    tmpfs_dentry_t *parent;
    link_t link;
} tmpfs_name_t;
 
/* Implementation of hash table interface for the names hash table. */
static hash_index_t names_hash(unsigned long *key)
{
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) *key;
    return dentry->index % NAMES_BUCKETS;
}
 
static int names_compare(unsigned long *key, hash_count_t keys, link_t *item)
{
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) *key;
    tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
        link);
    return dentry == namep->parent;
}
 
static void names_remove_callback(link_t *item)
{
    tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
        link);
    free(namep->name);
    free(namep);
}
 
/** TMPFS node names hash table operations. */
static hash_table_operations_t names_ops = {
    .hash = names_hash,
    .compare = names_compare,
    .remove_callback = names_remove_callback
};
 
static void tmpfs_name_initialize(tmpfs_name_t *namep)
{
    namep->name = NULL;
    namep->parent = NULL;
    link_initialize(&namep->link);
}
 
static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
{
    dentry->index = 0;
    dentry->sibling = NULL;
    dentry->child = NULL;
    dentry->type = TMPFS_NONE;
    dentry->lnkcnt = 0;
    dentry->size = 0;
    dentry->data = NULL;
    link_initialize(&dentry->dh_link);
    return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,
        &names_ops);
}
 
static bool tmpfs_init(void)
{
    if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
        return false;
    root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);
    if (!root) {
        hash_table_destroy(&dentries);
        return false;
    }
    root->lnkcnt = 1;
    return true;
}
 
/** Compare one component of path to a directory entry.
 *
 * @param prnt      Node from which we descended.
 * @param chld      Node to compare the path component with.
 * @param component Array of characters holding component name.
 *
 * @return      True on match, false otherwise.
 */
bool tmpfs_match(void *prnt, void *chld, const char *component)
{
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
    tmpfs_dentry_t *childp = (tmpfs_dentry_t *) chld;
 
    unsigned long key = (unsigned long) parentp;
    link_t *hlp = hash_table_find(&childp->names, &key);
    assert(hlp);
    tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);
 
    return !strcmp(namep->name, component);
}
 
void *
tmpfs_node_get(fs_handle_t fs_handle, dev_handle_t dev_handle, fs_index_t index)
{
    unsigned long key = index;
    link_t *lnk = hash_table_find(&dentries, &key);
    if (!lnk)
        return NULL;
    return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);
}
 
void *tmpfs_create_node(int lflag)
{
    assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
 
    tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
    if (!node)
        return NULL;
 
    if (!tmpfs_dentry_initialize(node)) {
        free(node);
        return NULL;
    }
    node->index = tmpfs_next_index++;
    if (lflag & L_DIRECTORY)
        node->type = TMPFS_DIRECTORY;
    else
        node->type = TMPFS_FILE;
 
    /* Insert the new node into the dentry hash table. */
    unsigned long key = node->index;
    hash_table_insert(&dentries, &key, &node->dh_link);
    return (void *) node;
}
 
bool tmpfs_link_node(void *prnt, void *chld, const char *nm)
{
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
    tmpfs_dentry_t *childp = (tmpfs_dentry_t *) chld;
 
    assert(parentp->type == TMPFS_DIRECTORY);
 
    tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));
    if (!namep)
        return false;
    tmpfs_name_initialize(namep);
    size_t len = strlen(nm);
    namep->name = malloc(len + 1);
    if (!namep->name) {
        free(namep);
        return false;
    }
    strcpy(namep->name, nm);
    namep->parent = parentp;
   
    childp->lnkcnt++;
 
    unsigned long key = (unsigned long) parentp;
    hash_table_insert(&childp->names, &key, &namep->link);
 
    /* Insert the new node into the namespace. */
    if (parentp->child) {
        tmpfs_dentry_t *tmp = parentp->child;
        while (tmp->sibling)
            tmp = tmp->sibling;
        tmp->sibling = childp;
    } else {
        parentp->child = childp;
    }
 
    return true;
}
 
int tmpfs_unlink_node(void *prnt, void *chld)
{
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *)prnt;
    tmpfs_dentry_t *childp = (tmpfs_dentry_t *)chld;
 
    if (!parentp)
        return EBUSY;
 
    if (childp->child)
        return ENOTEMPTY;
 
    if (parentp->child == childp) {
        parentp->child = childp->sibling;
    } else {
        /* TODO: consider doubly linked list for organizing siblings. */
        tmpfs_dentry_t *tmp = parentp->child;
        while (tmp->sibling != childp)
            tmp = tmp->sibling;
        tmp->sibling = childp->sibling;
    }
    childp->sibling = NULL;
 
    unsigned long key = (unsigned long) parentp;
    hash_table_remove(&childp->names, &key, 1);
 
    childp->lnkcnt--;
 
    return EOK;
}
 
void tmpfs_destroy_node(void *nodep)
{
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
   
    assert(!dentry->lnkcnt);
    assert(!dentry->child);
    assert(!dentry->sibling);
 
    unsigned long key = dentry->index;
    hash_table_remove(&dentries, &key, 1);
 
    hash_table_destroy(&dentry->names);
 
    if (dentry->type == TMPFS_FILE)
        free(dentry->data);
    free(dentry);
}
 
void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    /* Initialize TMPFS. */
    if (!root && !tmpfs_init()) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
}
 
void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    unsigned long key = index;
    hlp = hash_table_find(&dentries, &key);
    if (!hlp) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
        dh_link);
 
    /*
     * Receive the read request.
     */
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_read_receive(&callid, &len)) {
        ipc_answer_0(callid, EINVAL);  
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    size_t bytes;
    if (dentry->type == TMPFS_FILE) {
        bytes = max(0, min(dentry->size - pos, len));
        (void) ipc_data_read_finalize(callid, dentry->data + pos,
            bytes);
    } else {
        int i;
        tmpfs_dentry_t *cur;
       
        assert(dentry->type == TMPFS_DIRECTORY);
       
        /*
         * Yes, we really use O(n) algorithm here.
         * If it bothers someone, it could be fixed by introducing a
         * hash table.
         */
        for (i = 0, cur = dentry->child; i < pos && cur; i++,
            cur = cur->sibling)
            ;
 
        if (!cur) {
            ipc_answer_0(callid, ENOENT);
            ipc_answer_1(rid, ENOENT, 0);
            return;
        }
 
        unsigned long key = (unsigned long) dentry;
        link_t *hlp = hash_table_find(&cur->names, &key);
        assert(hlp);
        tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,
            link);
 
        (void) ipc_data_read_finalize(callid, namep->name,
            strlen(namep->name) + 1);
        bytes = 1;
    }
 
    /*
     * Answer the VFS_READ call.
     */
    ipc_answer_1(rid, EOK, bytes);
}
 
void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    unsigned long key = index;
    hlp = hash_table_find(&dentries, &key);
    if (!hlp) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
        dh_link);
 
    /*
     * Receive the write request.
     */
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_write_receive(&callid, &len)) {
        ipc_answer_0(callid, EINVAL);  
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    /*
     * Check whether the file needs to grow.
     */
    if (pos + len <= dentry->size) {
        /* The file size is not changing. */
        (void) ipc_data_write_finalize(callid, dentry->data + pos, len);
        ipc_answer_2(rid, EOK, len, dentry->size);
        return;
    }
    size_t delta = (pos + len) - dentry->size;
    /*
     * At this point, we are deliberately extremely straightforward and
     * simply realloc the contents of the file on every write that grows the
     * file. In the end, the situation might not be as bad as it may look:
     * our heap allocator can save us and just grow the block whenever
     * possible.
     */
    void *newdata = realloc(dentry->data, dentry->size + delta);
    if (!newdata) {
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_2(rid, EOK, 0, dentry->size);
        return;
    }
    /* Clear any newly allocated memory in order to emulate gaps. */
    memset(newdata + dentry->size, 0, delta);
    dentry->size += delta;
    dentry->data = newdata;
    (void) ipc_data_write_finalize(callid, dentry->data + pos, len);
    ipc_answer_2(rid, EOK, len, dentry->size);
}
 
void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    size_t size = (off_t)IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    unsigned long key = index;
    hlp = hash_table_find(&dentries, &key);
    if (!hlp) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
        dh_link);
 
    if (size == dentry->size) {
        ipc_answer_0(rid, EOK);
        return;
    }
 
    void *newdata = realloc(dentry->data, size);
    if (!newdata) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    if (size > dentry->size) {
        size_t delta = size - dentry->size;
        memset(newdata + dentry->size, 0, delta);
    }
    dentry->size = size;
    dentry->data = newdata;
    ipc_answer_0(rid, EOK);
}
 
void tmpfs_destroy(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
 
    link_t *hlp;
    unsigned long key = index;
    hlp = hash_table_find(&dentries, &key);
    if (!hlp) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
        dh_link);
    tmpfs_destroy_node(dentry);
    ipc_answer_0(rid, EOK);
}
 
/**
 * @}
 */
 

Rev 2770	Rev 2782
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup fs	29	/** @addtogroup fs
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file tmpfs_ops.c	34	* @file tmpfs_ops.c
35	* @brief Implementation of VFS operations for the TMPFS file system	35	* @brief Implementation of VFS operations for the TMPFS file system
36	* server.	36	* server.
37	*/	37	*/
38		38
39	#include "tmpfs.h"	39	#include "tmpfs.h"
40	#include "../../vfs/vfs.h"	40	#include "../../vfs/vfs.h"
41	#include <ipc/ipc.h>	41	#include <ipc/ipc.h>
42	#include <async.h>	42	#include <async.h>
43	#include <errno.h>	43	#include <errno.h>
44	#include <atomic.h>	44	#include <atomic.h>
45	#include <stdlib.h>	45	#include <stdlib.h>
46	#include <string.h>	46	#include <string.h>
47	#include <stdio.h>	47	#include <stdio.h>
48	#include <assert.h>	48	#include <assert.h>
49	#include <sys/types.h>	49	#include <sys/types.h>
50	#include <libadt/hash_table.h>	50	#include <libadt/hash_table.h>
51	#include <as.h>	51	#include <as.h>
52	#include <libfs.h>	52	#include <libfs.h>
53		53
54	#define min(a, b) ((a) < (b) ? (a) : (b))	54	#define min(a, b) ((a) < (b) ? (a) : (b))
55	#define max(a, b) ((a) > (b) ? (a) : (b))	55	#define max(a, b) ((a) > (b) ? (a) : (b))
56		56
57	#define DENTRIES_BUCKETS 256	57	#define DENTRIES_BUCKETS 256
58		58
59	#define NAMES_BUCKETS 4	59	#define NAMES_BUCKETS 4
60		60
61	/*	61	/*
62	* For now, we don't distinguish between different dev_handles/instances. All	62	* For now, we don't distinguish between different dev_handles/instances. All
63	* requests resolve to the only instance, rooted in the following variable.	63	* requests resolve to the only instance, rooted in the following variable.
64	*/	64	*/
65	static tmpfs_dentry_t *root;	65	static tmpfs_dentry_t *root;
66		66
67	/*	67	/*
68	* Implementation of the libfs interface.	68	* Implementation of the libfs interface.
69	*/	69	*/
70		70
71	/* Forward declarations of static functions. */	71	/* Forward declarations of static functions. */
72	static bool tmpfs_match(void , void , const char *);	72	static bool tmpfs_match(void , void , const char *);
73	static void *tmpfs_node_get(fs_handle_t, dev_handle_t, fs_index_t);	73	static void *tmpfs_node_get(fs_handle_t, dev_handle_t, fs_index_t);
74	static void *tmpfs_create_node(int);	74	static void *tmpfs_create_node(int);
75	static bool tmpfs_link_node(void , void , const char *);	75	static bool tmpfs_link_node(void , void , const char *);
76	static int tmpfs_unlink_node(void , void );	76	static int tmpfs_unlink_node(void , void );
77	static void tmpfs_destroy_node(void *);	77	static void tmpfs_destroy_node(void *);
78		78
79	/* Implementation of helper functions. */	79	/* Implementation of helper functions. */
80	static fs_index_t tmpfs_index_get(void *nodep)	80	static fs_index_t tmpfs_index_get(void *nodep)
81	{	81	{
82	return ((tmpfs_dentry_t *) nodep)->index;	82	return ((tmpfs_dentry_t *) nodep)->index;
83	}	83	}
84		84
85	static size_t tmpfs_size_get(void *nodep)	85	static size_t tmpfs_size_get(void *nodep)
86	{	86	{
87	return ((tmpfs_dentry_t *) nodep)->size;	87	return ((tmpfs_dentry_t *) nodep)->size;
88	}	88	}
89		89
90	static unsigned tmpfs_lnkcnt_get(void *nodep)	90	static unsigned tmpfs_lnkcnt_get(void *nodep)
91	{	91	{
92	return ((tmpfs_dentry_t *) nodep)->lnkcnt;	92	return ((tmpfs_dentry_t *) nodep)->lnkcnt;
93	}	93	}
94		94
95	static void tmpfs_child_get(void nodep)	95	static void tmpfs_child_get(void nodep)
96	{	96	{
97	return ((tmpfs_dentry_t *) nodep)->child;	97	return ((tmpfs_dentry_t *) nodep)->child;
98	}	98	}
99		99
100	static void tmpfs_sibling_get(void nodep)	100	static void tmpfs_sibling_get(void nodep)
101	{	101	{
102	return ((tmpfs_dentry_t *) nodep)->sibling;	102	return ((tmpfs_dentry_t *) nodep)->sibling;
103	}	103	}
104		104
105	static void *tmpfs_root_get(void)	105	static void *tmpfs_root_get(void)
106	{	106	{
107	return root;	107	return root;
108	}	108	}
109		109
110	static char tmpfs_plb_get_char(unsigned pos)	110	static char tmpfs_plb_get_char(unsigned pos)
111	{	111	{
112	return tmpfs_reg.plb_ro[pos % PLB_SIZE];	112	return tmpfs_reg.plb_ro[pos % PLB_SIZE];
113	}	113	}
114		114
115	static bool tmpfs_is_directory(void *nodep)	115	static bool tmpfs_is_directory(void *nodep)
116	{	116	{
117	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;	117	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
118	}	118	}
119		119
120	static bool tmpfs_is_file(void *nodep)	120	static bool tmpfs_is_file(void *nodep)
121	{	121	{
122	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;	122	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
123	}	123	}
124		124
125	/** libfs operations */	125	/** libfs operations */
126	libfs_ops_t tmpfs_libfs_ops = {	126	libfs_ops_t tmpfs_libfs_ops = {
127	.match = tmpfs_match,	127	.match = tmpfs_match,
128	.node_get = tmpfs_node_get,	128	.node_get = tmpfs_node_get,
129	.create = tmpfs_create_node,	129	.create = tmpfs_create_node,
130	.destroy = tmpfs_destroy_node,	130	.destroy = tmpfs_destroy_node,
131	.link = tmpfs_link_node,	131	.link = tmpfs_link_node,
132	.unlink = tmpfs_unlink_node,	132	.unlink = tmpfs_unlink_node,
133	.index_get = tmpfs_index_get,	133	.index_get = tmpfs_index_get,
134	.size_get = tmpfs_size_get,	134	.size_get = tmpfs_size_get,
135	.lnkcnt_get = tmpfs_lnkcnt_get,	135	.lnkcnt_get = tmpfs_lnkcnt_get,
136	.child_get = tmpfs_child_get,	136	.child_get = tmpfs_child_get,
137	.sibling_get = tmpfs_sibling_get,	137	.sibling_get = tmpfs_sibling_get,
138	.root_get = tmpfs_root_get,	138	.root_get = tmpfs_root_get,
139	.plb_get_char = tmpfs_plb_get_char,	139	.plb_get_char = tmpfs_plb_get_char,
140	.is_directory = tmpfs_is_directory,	140	.is_directory = tmpfs_is_directory,
141	.is_file = tmpfs_is_file	141	.is_file = tmpfs_is_file
142	};	142	};
143		143
144	/** Hash table of all directory entries. */	144	/** Hash table of all directory entries. */
145	hash_table_t dentries;	145	hash_table_t dentries;
146		146
147	/* Implementation of hash table interface for the dentries hash table. */	147	/* Implementation of hash table interface for the dentries hash table. */
148	static hash_index_t dentries_hash(unsigned long *key)	148	static hash_index_t dentries_hash(unsigned long *key)
149	{	149	{
150	return *key % DENTRIES_BUCKETS;	150	return *key % DENTRIES_BUCKETS;
151	}	151	}
152		152
153	static int dentries_compare(unsigned long *key, hash_count_t keys,	153	static int dentries_compare(unsigned long *key, hash_count_t keys,
154	link_t *item)	154	link_t *item)
155	{	155	{
156	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,	156	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
157	dh_link);	157	dh_link);
158	return dentry->index == *key;	158	return dentry->index == *key;
159	}	159	}
160		160
161	static void dentries_remove_callback(link_t *item)	161	static void dentries_remove_callback(link_t *item)
162	{	162	{
163	}	163	}
164		164
165	/** TMPFS dentries hash table operations. */	165	/** TMPFS dentries hash table operations. */
166	hash_table_operations_t dentries_ops = {	166	hash_table_operations_t dentries_ops = {
167	.hash = dentries_hash,	167	.hash = dentries_hash,
168	.compare = dentries_compare,	168	.compare = dentries_compare,
169	.remove_callback = dentries_remove_callback	169	.remove_callback = dentries_remove_callback
170	};	170	};
171		171
172	fs_index_t tmpfs_next_index = 1;	172	fs_index_t tmpfs_next_index = 1;
173		173
174	typedef struct {	174	typedef struct {
175	char *name;	175	char *name;
176	tmpfs_dentry_t *parent;	176	tmpfs_dentry_t *parent;
177	link_t link;	177	link_t link;
178	} tmpfs_name_t;	178	} tmpfs_name_t;
179		179
180	/* Implementation of hash table interface for the names hash table. */	180	/* Implementation of hash table interface for the names hash table. */
181	static hash_index_t names_hash(unsigned long *key)	181	static hash_index_t names_hash(unsigned long *key)
182	{	182	{
183	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	183	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
184	return dentry->index % NAMES_BUCKETS;	184	return dentry->index % NAMES_BUCKETS;
185	}	185	}
186		186
187	static int names_compare(unsigned long key, hash_count_t keys, link_t item)	187	static int names_compare(unsigned long key, hash_count_t keys, link_t item)
188	{	188	{
189	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	189	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
190	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	190	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
191	link);	191	link);
192	return dentry == namep->parent;	192	return dentry == namep->parent;
193	}	193	}
194		194
195	static void names_remove_callback(link_t *item)	195	static void names_remove_callback(link_t *item)
196	{	196	{
197	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	197	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
198	link);	198	link);
199	free(namep->name);	199	free(namep->name);
200	free(namep);	200	free(namep);
201	}	201	}
202		202
203	/** TMPFS node names hash table operations. */	203	/** TMPFS node names hash table operations. */
204	static hash_table_operations_t names_ops = {	204	static hash_table_operations_t names_ops = {
205	.hash = names_hash,	205	.hash = names_hash,
206	.compare = names_compare,	206	.compare = names_compare,
207	.remove_callback = names_remove_callback	207	.remove_callback = names_remove_callback
208	};	208	};
209		209
210	static void tmpfs_name_initialize(tmpfs_name_t *namep)	210	static void tmpfs_name_initialize(tmpfs_name_t *namep)
211	{	211	{
212	namep->name = NULL;	212	namep->name = NULL;
213	namep->parent = NULL;	213	namep->parent = NULL;
214	link_initialize(&namep->link);	214	link_initialize(&namep->link);
215	}	215	}
216		216
217	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)	217	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
218	{	218	{
219	dentry->index = 0;	219	dentry->index = 0;
220	dentry->sibling = NULL;	220	dentry->sibling = NULL;
221	dentry->child = NULL;	221	dentry->child = NULL;
222	dentry->type = TMPFS_NONE;	222	dentry->type = TMPFS_NONE;
223	dentry->lnkcnt = 0;	223	dentry->lnkcnt = 0;
224	dentry->size = 0;	224	dentry->size = 0;
225	dentry->data = NULL;	225	dentry->data = NULL;
226	link_initialize(&dentry->dh_link);	226	link_initialize(&dentry->dh_link);
227	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,	227	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,
228	&names_ops);	228	&names_ops);
229	}	229	}
230		230
231	static bool tmpfs_init(void)	231	static bool tmpfs_init(void)
232	{	232	{
233	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))	233	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
234	return false;	234	return false;
235	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);	235	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);
236	if (!root) {	236	if (!root) {
237	hash_table_destroy(&dentries);	237	hash_table_destroy(&dentries);
238	return false;	238	return false;
239	}	239	}
240	root->lnkcnt = 1;	240	root->lnkcnt = 1;
241	return true;	241	return true;
242	}	242	}
243		243
244	/** Compare one component of path to a directory entry.	244	/** Compare one component of path to a directory entry.
245	*	245	*
246	* @param prnt Node from which we descended.	246	* @param prnt Node from which we descended.
247	* @param chld Node to compare the path component with.	247	* @param chld Node to compare the path component with.
248	* @param component Array of characters holding component name.	248	* @param component Array of characters holding component name.
249	*	249	*
250	* @return True on match, false otherwise.	250	* @return True on match, false otherwise.
251	*/	251	*/
252	bool tmpfs_match(void prnt, void chld, const char *component)	252	bool tmpfs_match(void prnt, void chld, const char *component)
253	{	253	{
254	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	254	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
255	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;	255	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;
256		256
257	unsigned long key = (unsigned long) parentp;	257	unsigned long key = (unsigned long) parentp;
258	link_t *hlp = hash_table_find(&childp->names, &key);	258	link_t *hlp = hash_table_find(&childp->names, &key);
259	assert(hlp);	259	assert(hlp);
260	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);	260	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);
261		261
262	return !strcmp(namep->name, component);	262	return !strcmp(namep->name, component);
263	}	263	}
264		264
265	void *	265	void *
266	tmpfs_node_get(fs_handle_t fs_handle, dev_handle_t dev_handle, fs_index_t index)	266	tmpfs_node_get(fs_handle_t fs_handle, dev_handle_t dev_handle, fs_index_t index)
267	{	267	{
268	unsigned long key = index;	268	unsigned long key = index;
269	link_t *lnk = hash_table_find(&dentries, &key);	269	link_t *lnk = hash_table_find(&dentries, &key);
270	if (!lnk)	270	if (!lnk)
271	return NULL;	271	return NULL;
272	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);	272	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);
273	}	273	}
274		274
275	void *tmpfs_create_node(int lflag)	275	void *tmpfs_create_node(int lflag)
276	{	276	{
277	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));	277	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
278		278
279	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));	279	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
280	if (!node)	280	if (!node)
281	return NULL;	281	return NULL;
282		282
283	if (!tmpfs_dentry_initialize(node)) {	283	if (!tmpfs_dentry_initialize(node)) {
284	free(node);	284	free(node);
285	return NULL;	285	return NULL;
286	}	286	}
287	node->index = tmpfs_next_index++;	287	node->index = tmpfs_next_index++;
288	if (lflag & L_DIRECTORY)	288	if (lflag & L_DIRECTORY)
289	node->type = TMPFS_DIRECTORY;	289	node->type = TMPFS_DIRECTORY;
290	else	290	else
291	node->type = TMPFS_FILE;	291	node->type = TMPFS_FILE;
292		292
293	/* Insert the new node into the dentry hash table. */	293	/* Insert the new node into the dentry hash table. */
294	unsigned long key = node->index;	294	unsigned long key = node->index;
295	hash_table_insert(&dentries, &key, &node->dh_link);	295	hash_table_insert(&dentries, &key, &node->dh_link);
296	return (void *) node;	296	return (void *) node;
297	}	297	}
298		298
299	bool tmpfs_link_node(void prnt, void chld, const char *nm)	299	bool tmpfs_link_node(void prnt, void chld, const char *nm)
300	{	300	{
301	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	301	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
302	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;	302	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;
303		303
304	assert(parentp->type == TMPFS_DIRECTORY);	304	assert(parentp->type == TMPFS_DIRECTORY);
305		305
306	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));	306	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));
307	if (!namep)	307	if (!namep)
308	return false;	308	return false;
309	tmpfs_name_initialize(namep);	309	tmpfs_name_initialize(namep);
310	size_t len = strlen(nm);	310	size_t len = strlen(nm);
311	namep->name = malloc(len + 1);	311	namep->name = malloc(len + 1);
312	if (!namep->name) {	312	if (!namep->name) {
313	free(namep);	313	free(namep);
314	return false;	314	return false;
315	}	315	}
316	strcpy(namep->name, nm);	316	strcpy(namep->name, nm);
317	namep->parent = parentp;	317	namep->parent = parentp;
318		318
319	childp->lnkcnt++;	319	childp->lnkcnt++;
320		320
321	unsigned long key = (unsigned long) parentp;	321	unsigned long key = (unsigned long) parentp;
322	hash_table_insert(&childp->names, &key, &namep->link);	322	hash_table_insert(&childp->names, &key, &namep->link);
323		323
324	/* Insert the new node into the namespace. */	324	/* Insert the new node into the namespace. */
325	if (parentp->child) {	325	if (parentp->child) {
326	tmpfs_dentry_t *tmp = parentp->child;	326	tmpfs_dentry_t *tmp = parentp->child;
327	while (tmp->sibling)	327	while (tmp->sibling)
328	tmp = tmp->sibling;	328	tmp = tmp->sibling;
329	tmp->sibling = childp;	329	tmp->sibling = childp;
330	} else {	330	} else {
331	parentp->child = childp;	331	parentp->child = childp;
332	}	332	}
333		333
334	return true;	334	return true;
335	}	335	}
336		336
337	int tmpfs_unlink_node(void prnt, void chld)	337	int tmpfs_unlink_node(void prnt, void chld)
338	{	338	{
339	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;	339	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;
340	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;	340	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;
341		341
342	if (!parentp)	342	if (!parentp)
343	return EBUSY;	343	return EBUSY;
344		344
345	if (childp->child)	345	if (childp->child)
346	return ENOTEMPTY;	346	return ENOTEMPTY;
347		347
348	if (parentp->child == childp) {	348	if (parentp->child == childp) {
349	parentp->child = childp->sibling;	349	parentp->child = childp->sibling;
350	} else {	350	} else {
351	/* TODO: consider doubly linked list for organizing siblings. */	351	/* TODO: consider doubly linked list for organizing siblings. */
352	tmpfs_dentry_t *tmp = parentp->child;	352	tmpfs_dentry_t *tmp = parentp->child;
353	while (tmp->sibling != childp)	353	while (tmp->sibling != childp)
354	tmp = tmp->sibling;	354	tmp = tmp->sibling;
355	tmp->sibling = childp->sibling;	355	tmp->sibling = childp->sibling;
356	}	356	}
357	childp->sibling = NULL;	357	childp->sibling = NULL;
358		358
359	unsigned long key = (unsigned long) parentp;	359	unsigned long key = (unsigned long) parentp;
360	hash_table_remove(&childp->names, &key, 1);	360	hash_table_remove(&childp->names, &key, 1);
361		361
362	childp->lnkcnt--;	362	childp->lnkcnt--;
363		363
364	return EOK;	364	return EOK;
365	}	365	}
366		366
367	void tmpfs_destroy_node(void *nodep)	367	void tmpfs_destroy_node(void *nodep)
368	{	368	{
369	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;	369	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;
370		370
371	assert(!dentry->lnkcnt);	371	assert(!dentry->lnkcnt);
372	assert(!dentry->child);	372	assert(!dentry->child);
373	assert(!dentry->sibling);	373	assert(!dentry->sibling);
374		374
375	unsigned long key = dentry->index;	375	unsigned long key = dentry->index;
376	hash_table_remove(&dentries, &key, 1);	376	hash_table_remove(&dentries, &key, 1);
377		377
378	hash_table_destroy(&dentry->names);	378	hash_table_destroy(&dentry->names);
379		379
380	if (dentry->type == TMPFS_FILE)	380	if (dentry->type == TMPFS_FILE)
381	free(dentry->data);	381	free(dentry->data);
382	free(dentry);	382	free(dentry);
383	}	383	}
384		384
385	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)	385	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
386	{	386	{
387	/* Initialize TMPFS. */	387	/* Initialize TMPFS. */
388	if (!root && !tmpfs_init()) {	388	if (!root && !tmpfs_init()) {
389	ipc_answer_0(rid, ENOMEM);	389	ipc_answer_0(rid, ENOMEM);
390	return;	390	return;
391	}	391	}
392	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);	392	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
393	}	393	}
394		394
395	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)	395	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
396	{	396	{
397	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	397	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
398	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	398	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
399	off_t pos = (off_t)IPC_GET_ARG3(*request);	399	off_t pos = (off_t)IPC_GET_ARG3(*request);
400		400
401	/*	401	/*
402	* Lookup the respective dentry.	402	* Lookup the respective dentry.
403	*/	403	*/
404	link_t *hlp;	404	link_t *hlp;
405	unsigned long key = index;	405	unsigned long key = index;
406	hlp = hash_table_find(&dentries, &key);	406	hlp = hash_table_find(&dentries, &key);
407	if (!hlp) {	407	if (!hlp) {
408	ipc_answer_0(rid, ENOENT);	408	ipc_answer_0(rid, ENOENT);
409	return;	409	return;
410	}	410	}
411	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	411	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
412	dh_link);	412	dh_link);
413		413
414	/*	414	/*
415	* Receive the read request.	415	* Receive the read request.
416	*/	416	*/
417	ipc_callid_t callid;	417	ipc_callid_t callid;
418	size_t len;	418	size_t len;
419	if (!ipc_data_read_receive(&callid, &len)) {	419	if (!ipc_data_read_receive(&callid, &len)) {
420	ipc_answer_0(callid, EINVAL);	420	ipc_answer_0(callid, EINVAL);
421	ipc_answer_0(rid, EINVAL);	421	ipc_answer_0(rid, EINVAL);
422	return;	422	return;
423	}	423	}
424		424
425	size_t bytes;	425	size_t bytes;
426	if (dentry->type == TMPFS_FILE) {	426	if (dentry->type == TMPFS_FILE) {
427	bytes = max(0, min(dentry->size - pos, len));	427	bytes = max(0, min(dentry->size - pos, len));
428	(void) ipc_data_read_finalize(callid, dentry->data + pos,	428	(void) ipc_data_read_finalize(callid, dentry->data + pos,
429	bytes);	429	bytes);
430	} else {	430	} else {
431	int i;	431	int i;
432	tmpfs_dentry_t *cur;	432	tmpfs_dentry_t *cur;
433		433
434	assert(dentry->type == TMPFS_DIRECTORY);	434	assert(dentry->type == TMPFS_DIRECTORY);
435		435
436	/*	436	/*
437	* Yes, we really use O(n) algorithm here.	437	* Yes, we really use O(n) algorithm here.
438	* If it bothers someone, it could be fixed by introducing a	438	* If it bothers someone, it could be fixed by introducing a
439	* hash table.	439	* hash table.
440	*/	440	*/
441	for (i = 0, cur = dentry->child; i < pos && cur; i++,	441	for (i = 0, cur = dentry->child; i < pos && cur; i++,
442	cur = cur->sibling)	442	cur = cur->sibling)
443	;	443	;
444		444
445	if (!cur) {	445	if (!cur) {
446	ipc_answer_0(callid, ENOENT);	446	ipc_answer_0(callid, ENOENT);
447	ipc_answer_1(rid, ENOENT, 0);	447	ipc_answer_1(rid, ENOENT, 0);
448	return;	448	return;
449	}	449	}
450		450
451	unsigned long key = (unsigned long) dentry;	451	unsigned long key = (unsigned long) dentry;
452	link_t *hlp = hash_table_find(&cur->names, &key);	452	link_t *hlp = hash_table_find(&cur->names, &key);
453	assert(hlp);	453	assert(hlp);
454	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,	454	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,
455	link);	455	link);
456		456
457	(void) ipc_data_read_finalize(callid, namep->name,	457	(void) ipc_data_read_finalize(callid, namep->name,
458	strlen(namep->name) + 1);	458	strlen(namep->name) + 1);
459	bytes = 1;	459	bytes = 1;
460	}	460	}
461		461
462	/*	462	/*
463	* Answer the VFS_READ call.	463	* Answer the VFS_READ call.
464	*/	464	*/
465	ipc_answer_1(rid, EOK, bytes);	465	ipc_answer_1(rid, EOK, bytes);
466	}	466	}
467		467
468	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)	468	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
469	{	469	{
470	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	470	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
471	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	471	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
472	off_t pos = (off_t)IPC_GET_ARG3(*request);	472	off_t pos = (off_t)IPC_GET_ARG3(*request);
473		473
474	/*	474	/*
475	* Lookup the respective dentry.	475	* Lookup the respective dentry.
476	*/	476	*/
477	link_t *hlp;	477	link_t *hlp;
478	unsigned long key = index;	478	unsigned long key = index;
479	hlp = hash_table_find(&dentries, &key);	479	hlp = hash_table_find(&dentries, &key);
480	if (!hlp) {	480	if (!hlp) {
481	ipc_answer_0(rid, ENOENT);	481	ipc_answer_0(rid, ENOENT);
482	return;	482	return;
483	}	483	}
484	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	484	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
485	dh_link);	485	dh_link);
486		486
487	/*	487	/*
488	* Receive the write request.	488	* Receive the write request.
489	*/	489	*/
490	ipc_callid_t callid;	490	ipc_callid_t callid;
491	size_t len;	491	size_t len;
492	if (!ipc_data_write_receive(&callid, &len)) {	492	if (!ipc_data_write_receive(&callid, &len)) {
493	ipc_answer_0(callid, EINVAL);	493	ipc_answer_0(callid, EINVAL);
494	ipc_answer_0(rid, EINVAL);	494	ipc_answer_0(rid, EINVAL);
495	return;	495	return;
496	}	496	}
497		497
498	/*	498	/*
499	* Check whether the file needs to grow.	499	* Check whether the file needs to grow.
500	*/	500	*/

Subversion Repositories HelenOS

(root)/tags/0.3.0/uspace/srv/fs/tmpfs/tmpfs_ops.c – Rev 2770 → 2782