WebSVN – HelenOS – Diff – /trunk/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 void *tmpfs_match(void *, const char *);
static void *tmpfs_node_get(dev_handle_t, fs_index_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 bool tmpfs_has_children(void *nodep)
{
    return ((tmpfs_dentry_t *) nodep)->child != NULL;
}
 
static void *tmpfs_root_get(dev_handle_t dev_handle)
{
    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,
    .has_children = tmpfs_has_children,
    .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 parentp   Pointer to node from which we descended.
 * @param childp    Pointer to node to compare the path component with.
 * @param component Array of characters holding component name.
 *
 * @return      True on match, false otherwise.
 */
static bool
tmpfs_match_one(tmpfs_dentry_t *parentp, tmpfs_dentry_t *childp,
    const char *component)
{
    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_match(void *prnt, const char *component)
{
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
    tmpfs_dentry_t *childp = parentp->child;
 
    while (childp && !tmpfs_match_one(parentp, childp, component))
        childp = childp->sibling;
 
    return (void *) childp;
}
 
void *
tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)
{
    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 2831	Rev 2844
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 void tmpfs_match(void , const char *);	72	static void tmpfs_match(void , const char *);
73	static void *tmpfs_node_get(dev_handle_t, fs_index_t, fs_index_t);	73	static void *tmpfs_node_get(dev_handle_t, fs_index_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 bool tmpfs_has_children(void *nodep)	95	static bool tmpfs_has_children(void *nodep)
96	{	96	{
97	return ((tmpfs_dentry_t *) nodep)->child != NULL;	97	return ((tmpfs_dentry_t *) nodep)->child != NULL;
98	}	98	}
99		99
100	static void *tmpfs_root_get(void)	100	static void *tmpfs_root_get(dev_handle_t dev_handle)
101	{	101	{
102	return root;	102	return root;
103	}	103	}
104		104
105	static char tmpfs_plb_get_char(unsigned pos)	105	static char tmpfs_plb_get_char(unsigned pos)
106	{	106	{
107	return tmpfs_reg.plb_ro[pos % PLB_SIZE];	107	return tmpfs_reg.plb_ro[pos % PLB_SIZE];
108	}	108	}
109		109
110	static bool tmpfs_is_directory(void *nodep)	110	static bool tmpfs_is_directory(void *nodep)
111	{	111	{
112	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;	112	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
113	}	113	}
114		114
115	static bool tmpfs_is_file(void *nodep)	115	static bool tmpfs_is_file(void *nodep)
116	{	116	{
117	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;	117	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
118	}	118	}
119		119
120	/** libfs operations */	120	/** libfs operations */
121	libfs_ops_t tmpfs_libfs_ops = {	121	libfs_ops_t tmpfs_libfs_ops = {
122	.match = tmpfs_match,	122	.match = tmpfs_match,
123	.node_get = tmpfs_node_get,	123	.node_get = tmpfs_node_get,
124	.create = tmpfs_create_node,	124	.create = tmpfs_create_node,
125	.destroy = tmpfs_destroy_node,	125	.destroy = tmpfs_destroy_node,
126	.link = tmpfs_link_node,	126	.link = tmpfs_link_node,
127	.unlink = tmpfs_unlink_node,	127	.unlink = tmpfs_unlink_node,
128	.index_get = tmpfs_index_get,	128	.index_get = tmpfs_index_get,
129	.size_get = tmpfs_size_get,	129	.size_get = tmpfs_size_get,
130	.lnkcnt_get = tmpfs_lnkcnt_get,	130	.lnkcnt_get = tmpfs_lnkcnt_get,
131	.has_children = tmpfs_has_children,	131	.has_children = tmpfs_has_children,
132	.root_get = tmpfs_root_get,	132	.root_get = tmpfs_root_get,
133	.plb_get_char = tmpfs_plb_get_char,	133	.plb_get_char = tmpfs_plb_get_char,
134	.is_directory = tmpfs_is_directory,	134	.is_directory = tmpfs_is_directory,
135	.is_file = tmpfs_is_file	135	.is_file = tmpfs_is_file
136	};	136	};
137		137
138	/** Hash table of all directory entries. */	138	/** Hash table of all directory entries. */
139	hash_table_t dentries;	139	hash_table_t dentries;
140		140
141	/* Implementation of hash table interface for the dentries hash table. */	141	/* Implementation of hash table interface for the dentries hash table. */
142	static hash_index_t dentries_hash(unsigned long *key)	142	static hash_index_t dentries_hash(unsigned long *key)
143	{	143	{
144	return *key % DENTRIES_BUCKETS;	144	return *key % DENTRIES_BUCKETS;
145	}	145	}
146		146
147	static int dentries_compare(unsigned long *key, hash_count_t keys,	147	static int dentries_compare(unsigned long *key, hash_count_t keys,
148	link_t *item)	148	link_t *item)
149	{	149	{
150	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,	150	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
151	dh_link);	151	dh_link);
152	return dentry->index == *key;	152	return dentry->index == *key;
153	}	153	}
154		154
155	static void dentries_remove_callback(link_t *item)	155	static void dentries_remove_callback(link_t *item)
156	{	156	{
157	}	157	}
158		158
159	/** TMPFS dentries hash table operations. */	159	/** TMPFS dentries hash table operations. */
160	hash_table_operations_t dentries_ops = {	160	hash_table_operations_t dentries_ops = {
161	.hash = dentries_hash,	161	.hash = dentries_hash,
162	.compare = dentries_compare,	162	.compare = dentries_compare,
163	.remove_callback = dentries_remove_callback	163	.remove_callback = dentries_remove_callback
164	};	164	};
165		165
166	fs_index_t tmpfs_next_index = 1;	166	fs_index_t tmpfs_next_index = 1;
167		167
168	typedef struct {	168	typedef struct {
169	char *name;	169	char *name;
170	tmpfs_dentry_t *parent;	170	tmpfs_dentry_t *parent;
171	link_t link;	171	link_t link;
172	} tmpfs_name_t;	172	} tmpfs_name_t;
173		173
174	/* Implementation of hash table interface for the names hash table. */	174	/* Implementation of hash table interface for the names hash table. */
175	static hash_index_t names_hash(unsigned long *key)	175	static hash_index_t names_hash(unsigned long *key)
176	{	176	{
177	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	177	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
178	return dentry->index % NAMES_BUCKETS;	178	return dentry->index % NAMES_BUCKETS;
179	}	179	}
180		180
181	static int names_compare(unsigned long key, hash_count_t keys, link_t item)	181	static int names_compare(unsigned long key, hash_count_t keys, link_t item)
182	{	182	{
183	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	183	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
184	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	184	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
185	link);	185	link);
186	return dentry == namep->parent;	186	return dentry == namep->parent;
187	}	187	}
188		188
189	static void names_remove_callback(link_t *item)	189	static void names_remove_callback(link_t *item)
190	{	190	{
191	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	191	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
192	link);	192	link);
193	free(namep->name);	193	free(namep->name);
194	free(namep);	194	free(namep);
195	}	195	}
196		196
197	/** TMPFS node names hash table operations. */	197	/** TMPFS node names hash table operations. */
198	static hash_table_operations_t names_ops = {	198	static hash_table_operations_t names_ops = {
199	.hash = names_hash,	199	.hash = names_hash,
200	.compare = names_compare,	200	.compare = names_compare,
201	.remove_callback = names_remove_callback	201	.remove_callback = names_remove_callback
202	};	202	};
203		203
204	static void tmpfs_name_initialize(tmpfs_name_t *namep)	204	static void tmpfs_name_initialize(tmpfs_name_t *namep)
205	{	205	{
206	namep->name = NULL;	206	namep->name = NULL;
207	namep->parent = NULL;	207	namep->parent = NULL;
208	link_initialize(&namep->link);	208	link_initialize(&namep->link);
209	}	209	}
210		210
211	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)	211	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
212	{	212	{
213	dentry->index = 0;	213	dentry->index = 0;
214	dentry->sibling = NULL;	214	dentry->sibling = NULL;
215	dentry->child = NULL;	215	dentry->child = NULL;
216	dentry->type = TMPFS_NONE;	216	dentry->type = TMPFS_NONE;
217	dentry->lnkcnt = 0;	217	dentry->lnkcnt = 0;
218	dentry->size = 0;	218	dentry->size = 0;
219	dentry->data = NULL;	219	dentry->data = NULL;
220	link_initialize(&dentry->dh_link);	220	link_initialize(&dentry->dh_link);
221	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,	221	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,
222	&names_ops);	222	&names_ops);
223	}	223	}
224		224
225	static bool tmpfs_init(void)	225	static bool tmpfs_init(void)
226	{	226	{
227	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))	227	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
228	return false;	228	return false;
229	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);	229	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);
230	if (!root) {	230	if (!root) {
231	hash_table_destroy(&dentries);	231	hash_table_destroy(&dentries);
232	return false;	232	return false;
233	}	233	}
234	root->lnkcnt = 1;	234	root->lnkcnt = 1;
235	return true;	235	return true;
236	}	236	}
237		237
238	/** Compare one component of path to a directory entry.	238	/** Compare one component of path to a directory entry.
239	*	239	*
240	* @param parentp Pointer to node from which we descended.	240	* @param parentp Pointer to node from which we descended.
241	* @param childp Pointer to node to compare the path component with.	241	* @param childp Pointer to node to compare the path component with.
242	* @param component Array of characters holding component name.	242	* @param component Array of characters holding component name.
243	*	243	*
244	* @return True on match, false otherwise.	244	* @return True on match, false otherwise.
245	*/	245	*/
246	static bool	246	static bool
247	tmpfs_match_one(tmpfs_dentry_t parentp, tmpfs_dentry_t childp,	247	tmpfs_match_one(tmpfs_dentry_t parentp, tmpfs_dentry_t childp,
248	const char *component)	248	const char *component)
249	{	249	{
250	unsigned long key = (unsigned long) parentp;	250	unsigned long key = (unsigned long) parentp;
251	link_t *hlp = hash_table_find(&childp->names, &key);	251	link_t *hlp = hash_table_find(&childp->names, &key);
252	assert(hlp);	252	assert(hlp);
253	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);	253	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);
254	return !strcmp(namep->name, component);	254	return !strcmp(namep->name, component);
255	}	255	}
256		256
257	void tmpfs_match(void prnt, const char *component)	257	void tmpfs_match(void prnt, const char *component)
258	{	258	{
259	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	259	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
260	tmpfs_dentry_t *childp = parentp->child;	260	tmpfs_dentry_t *childp = parentp->child;
261		261
262	while (childp && !tmpfs_match_one(parentp, childp, component))	262	while (childp && !tmpfs_match_one(parentp, childp, component))
263	childp = childp->sibling;	263	childp = childp->sibling;
264		264
265	return (void *) childp;	265	return (void *) childp;
266	}	266	}
267		267
268	void *	268	void *
269	tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)	269	tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)
270	{	270	{
271	unsigned long key = index;	271	unsigned long key = index;
272	link_t *lnk = hash_table_find(&dentries, &key);	272	link_t *lnk = hash_table_find(&dentries, &key);
273	if (!lnk)	273	if (!lnk)
274	return NULL;	274	return NULL;
275	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);	275	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);
276	}	276	}
277		277
278	void *tmpfs_create_node(int lflag)	278	void *tmpfs_create_node(int lflag)
279	{	279	{
280	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));	280	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
281		281
282	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));	282	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
283	if (!node)	283	if (!node)
284	return NULL;	284	return NULL;
285		285
286	if (!tmpfs_dentry_initialize(node)) {	286	if (!tmpfs_dentry_initialize(node)) {
287	free(node);	287	free(node);
288	return NULL;	288	return NULL;
289	}	289	}
290	node->index = tmpfs_next_index++;	290	node->index = tmpfs_next_index++;
291	if (lflag & L_DIRECTORY)	291	if (lflag & L_DIRECTORY)
292	node->type = TMPFS_DIRECTORY;	292	node->type = TMPFS_DIRECTORY;
293	else	293	else
294	node->type = TMPFS_FILE;	294	node->type = TMPFS_FILE;
295		295
296	/* Insert the new node into the dentry hash table. */	296	/* Insert the new node into the dentry hash table. */
297	unsigned long key = node->index;	297	unsigned long key = node->index;
298	hash_table_insert(&dentries, &key, &node->dh_link);	298	hash_table_insert(&dentries, &key, &node->dh_link);
299	return (void *) node;	299	return (void *) node;
300	}	300	}
301		301
302	bool tmpfs_link_node(void prnt, void chld, const char *nm)	302	bool tmpfs_link_node(void prnt, void chld, const char *nm)
303	{	303	{
304	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	304	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
305	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;	305	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;
306		306
307	assert(parentp->type == TMPFS_DIRECTORY);	307	assert(parentp->type == TMPFS_DIRECTORY);
308		308
309	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));	309	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));
310	if (!namep)	310	if (!namep)
311	return false;	311	return false;
312	tmpfs_name_initialize(namep);	312	tmpfs_name_initialize(namep);
313	size_t len = strlen(nm);	313	size_t len = strlen(nm);
314	namep->name = malloc(len + 1);	314	namep->name = malloc(len + 1);
315	if (!namep->name) {	315	if (!namep->name) {
316	free(namep);	316	free(namep);
317	return false;	317	return false;
318	}	318	}
319	strcpy(namep->name, nm);	319	strcpy(namep->name, nm);
320	namep->parent = parentp;	320	namep->parent = parentp;
321		321
322	childp->lnkcnt++;	322	childp->lnkcnt++;
323		323
324	unsigned long key = (unsigned long) parentp;	324	unsigned long key = (unsigned long) parentp;
325	hash_table_insert(&childp->names, &key, &namep->link);	325	hash_table_insert(&childp->names, &key, &namep->link);
326		326
327	/* Insert the new node into the namespace. */	327	/* Insert the new node into the namespace. */
328	if (parentp->child) {	328	if (parentp->child) {
329	tmpfs_dentry_t *tmp = parentp->child;	329	tmpfs_dentry_t *tmp = parentp->child;
330	while (tmp->sibling)	330	while (tmp->sibling)
331	tmp = tmp->sibling;	331	tmp = tmp->sibling;
332	tmp->sibling = childp;	332	tmp->sibling = childp;
333	} else {	333	} else {
334	parentp->child = childp;	334	parentp->child = childp;
335	}	335	}
336		336
337	return true;	337	return true;
338	}	338	}
339		339
340	int tmpfs_unlink_node(void prnt, void chld)	340	int tmpfs_unlink_node(void prnt, void chld)
341	{	341	{
342	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;	342	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;
343	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;	343	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;
344		344
345	if (!parentp)	345	if (!parentp)
346	return EBUSY;	346	return EBUSY;
347		347
348	if (childp->child)	348	if (childp->child)
349	return ENOTEMPTY;	349	return ENOTEMPTY;
350		350
351	if (parentp->child == childp) {	351	if (parentp->child == childp) {
352	parentp->child = childp->sibling;	352	parentp->child = childp->sibling;
353	} else {	353	} else {
354	/* TODO: consider doubly linked list for organizing siblings. */	354	/* TODO: consider doubly linked list for organizing siblings. */
355	tmpfs_dentry_t *tmp = parentp->child;	355	tmpfs_dentry_t *tmp = parentp->child;
356	while (tmp->sibling != childp)	356	while (tmp->sibling != childp)
357	tmp = tmp->sibling;	357	tmp = tmp->sibling;
358	tmp->sibling = childp->sibling;	358	tmp->sibling = childp->sibling;
359	}	359	}
360	childp->sibling = NULL;	360	childp->sibling = NULL;
361		361
362	unsigned long key = (unsigned long) parentp;	362	unsigned long key = (unsigned long) parentp;
363	hash_table_remove(&childp->names, &key, 1);	363	hash_table_remove(&childp->names, &key, 1);
364		364
365	childp->lnkcnt--;	365	childp->lnkcnt--;
366		366
367	return EOK;	367	return EOK;
368	}	368	}
369		369
370	void tmpfs_destroy_node(void *nodep)	370	void tmpfs_destroy_node(void *nodep)
371	{	371	{
372	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;	372	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;
373		373
374	assert(!dentry->lnkcnt);	374	assert(!dentry->lnkcnt);
375	assert(!dentry->child);	375	assert(!dentry->child);
376	assert(!dentry->sibling);	376	assert(!dentry->sibling);
377		377
378	unsigned long key = dentry->index;	378	unsigned long key = dentry->index;
379	hash_table_remove(&dentries, &key, 1);	379	hash_table_remove(&dentries, &key, 1);
380		380
381	hash_table_destroy(&dentry->names);	381	hash_table_destroy(&dentry->names);
382		382
383	if (dentry->type == TMPFS_FILE)	383	if (dentry->type == TMPFS_FILE)
384	free(dentry->data);	384	free(dentry->data);
385	free(dentry);	385	free(dentry);
386	}	386	}
387		387
388	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)	388	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
389	{	389	{
390	/* Initialize TMPFS. */	390	/* Initialize TMPFS. */
391	if (!root && !tmpfs_init()) {	391	if (!root && !tmpfs_init()) {
392	ipc_answer_0(rid, ENOMEM);	392	ipc_answer_0(rid, ENOMEM);
393	return;	393	return;
394	}	394	}
395	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);	395	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
396	}	396	}
397		397
398	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)	398	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
399	{	399	{
400	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	400	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
401	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	401	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
402	off_t pos = (off_t)IPC_GET_ARG3(*request);	402	off_t pos = (off_t)IPC_GET_ARG3(*request);
403		403
404	/*	404	/*
405	* Lookup the respective dentry.	405	* Lookup the respective dentry.
406	*/	406	*/
407	link_t *hlp;	407	link_t *hlp;
408	unsigned long key = index;	408	unsigned long key = index;
409	hlp = hash_table_find(&dentries, &key);	409	hlp = hash_table_find(&dentries, &key);
410	if (!hlp) {	410	if (!hlp) {
411	ipc_answer_0(rid, ENOENT);	411	ipc_answer_0(rid, ENOENT);
412	return;	412	return;
413	}	413	}
414	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	414	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
415	dh_link);	415	dh_link);
416		416
417	/*	417	/*
418	* Receive the read request.	418	* Receive the read request.
419	*/	419	*/
420	ipc_callid_t callid;	420	ipc_callid_t callid;
421	size_t len;	421	size_t len;
422	if (!ipc_data_read_receive(&callid, &len)) {	422	if (!ipc_data_read_receive(&callid, &len)) {
423	ipc_answer_0(callid, EINVAL);	423	ipc_answer_0(callid, EINVAL);
424	ipc_answer_0(rid, EINVAL);	424	ipc_answer_0(rid, EINVAL);
425	return;	425	return;
426	}	426	}
427		427
428	size_t bytes;	428	size_t bytes;
429	if (dentry->type == TMPFS_FILE) {	429	if (dentry->type == TMPFS_FILE) {
430	bytes = max(0, min(dentry->size - pos, len));	430	bytes = max(0, min(dentry->size - pos, len));
431	(void) ipc_data_read_finalize(callid, dentry->data + pos,	431	(void) ipc_data_read_finalize(callid, dentry->data + pos,
432	bytes);	432	bytes);
433	} else {	433	} else {
434	int i;	434	int i;
435	tmpfs_dentry_t *cur;	435	tmpfs_dentry_t *cur;
436		436
437	assert(dentry->type == TMPFS_DIRECTORY);	437	assert(dentry->type == TMPFS_DIRECTORY);
438		438
439	/*	439	/*
440	* Yes, we really use O(n) algorithm here.	440	* Yes, we really use O(n) algorithm here.
441	* If it bothers someone, it could be fixed by introducing a	441	* If it bothers someone, it could be fixed by introducing a
442	* hash table.	442	* hash table.
443	*/	443	*/
444	for (i = 0, cur = dentry->child; i < pos && cur; i++,	444	for (i = 0, cur = dentry->child; i < pos && cur; i++,
445	cur = cur->sibling)	445	cur = cur->sibling)
446	;	446	;
447		447
448	if (!cur) {	448	if (!cur) {
449	ipc_answer_0(callid, ENOENT);	449	ipc_answer_0(callid, ENOENT);
450	ipc_answer_1(rid, ENOENT, 0);	450	ipc_answer_1(rid, ENOENT, 0);
451	return;	451	return;
452	}	452	}
453		453
454	unsigned long key = (unsigned long) dentry;	454	unsigned long key = (unsigned long) dentry;
455	link_t *hlp = hash_table_find(&cur->names, &key);	455	link_t *hlp = hash_table_find(&cur->names, &key);
456	assert(hlp);	456	assert(hlp);
457	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,	457	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,
458	link);	458	link);
459		459
460	(void) ipc_data_read_finalize(callid, namep->name,	460	(void) ipc_data_read_finalize(callid, namep->name,
461	strlen(namep->name) + 1);	461	strlen(namep->name) + 1);
462	bytes = 1;	462	bytes = 1;
463	}	463	}
464		464
465	/*	465	/*
466	* Answer the VFS_READ call.	466	* Answer the VFS_READ call.
467	*/	467	*/
468	ipc_answer_1(rid, EOK, bytes);	468	ipc_answer_1(rid, EOK, bytes);
469	}	469	}
470		470
471	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)	471	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
472	{	472	{
473	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	473	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
474	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	474	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
475	off_t pos = (off_t)IPC_GET_ARG3(*request);	475	off_t pos = (off_t)IPC_GET_ARG3(*request);
476		476
477	/*	477	/*
478	* Lookup the respective dentry.	478	* Lookup the respective dentry.
479	*/	479	*/
480	link_t *hlp;	480	link_t *hlp;
481	unsigned long key = index;	481	unsigned long key = index;
482	hlp = hash_table_find(&dentries, &key);	482	hlp = hash_table_find(&dentries, &key);
483	if (!hlp) {	483	if (!hlp) {
484	ipc_answer_0(rid, ENOENT);	484	ipc_answer_0(rid, ENOENT);
485	return;	485	return;
486	}	486	}
487	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	487	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
488	dh_link);	488	dh_link);
489		489
490	/*	490	/*
491	* Receive the write request.	491	* Receive the write request.
492	*/	492	*/
493	ipc_callid_t callid;	493	ipc_callid_t callid;
494	size_t len;	494	size_t len;
495	if (!ipc_data_write_receive(&callid, &len)) {	495	if (!ipc_data_write_receive(&callid, &len)) {
496	ipc_answer_0(callid, EINVAL);	496	ipc_answer_0(callid, EINVAL);
497	ipc_answer_0(rid, EINVAL);	497	ipc_answer_0(rid, EINVAL);
498	return;	498	return;
499	}	499	}
500		500

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(root)/trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c – Rev 2831 → 2844