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);
static void tmpfs_node_put(void *);
static void *tmpfs_create_node(int);
static bool tmpfs_link_node(void *, void *, const char *);
static int tmpfs_unlink_node(void *, void *);
static int 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,
    .node_put = tmpfs_node_put,
    .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)
{
    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_node_put(void *node)
{
    /* nothing to do */
}
 
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;
}
 
int 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);
    return EOK;
}
 
void tmpfs_mount(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t mr_dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t mr_index = (fs_index_t)IPC_GET_ARG2(*request);
    fs_handle_t mp_fs_handle = (fs_handle_t)IPC_GET_ARG3(*request);
    dev_handle_t mp_dev_handle = (dev_handle_t)IPC_GET_ARG4(*request);
    fs_index_t mp_index = (fs_index_t)IPC_GET_ARG5(*request);
    if ((mr_index == root->index) &&
        (mp_fs_handle == tmpfs_reg.fs_handle) &&
        (mp_index == mr_index))
        ipc_answer_0(rid, EOK);
    else
        ipc_answer_0(rid, ENOTSUP);
}
 
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);
    int rc;
 
    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);
    rc = tmpfs_destroy_node(dentry);
    ipc_answer_0(rid, rc);
}
 
/**
 * @}
 */
 

Rev 2863	Rev 2958
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);	73	static void *tmpfs_node_get(dev_handle_t, fs_index_t);
74	static void tmpfs_node_put(void *);	74	static void tmpfs_node_put(void *);
75	static void *tmpfs_create_node(int);	75	static void *tmpfs_create_node(int);
76	static bool tmpfs_link_node(void , void , const char *);	76	static bool tmpfs_link_node(void , void , const char *);
77	static int tmpfs_unlink_node(void , void );	77	static int tmpfs_unlink_node(void , void );
78	static int tmpfs_destroy_node(void *);	78	static int tmpfs_destroy_node(void *);
79		79
80	/* Implementation of helper functions. */	80	/* Implementation of helper functions. */
81	static fs_index_t tmpfs_index_get(void *nodep)	81	static fs_index_t tmpfs_index_get(void *nodep)
82	{	82	{
83	return ((tmpfs_dentry_t *) nodep)->index;	83	return ((tmpfs_dentry_t *) nodep)->index;
84	}	84	}
85		85
86	static size_t tmpfs_size_get(void *nodep)	86	static size_t tmpfs_size_get(void *nodep)
87	{	87	{
88	return ((tmpfs_dentry_t *) nodep)->size;	88	return ((tmpfs_dentry_t *) nodep)->size;
89	}	89	}
90		90
91	static unsigned tmpfs_lnkcnt_get(void *nodep)	91	static unsigned tmpfs_lnkcnt_get(void *nodep)
92	{	92	{
93	return ((tmpfs_dentry_t *) nodep)->lnkcnt;	93	return ((tmpfs_dentry_t *) nodep)->lnkcnt;
94	}	94	}
95		95
96	static bool tmpfs_has_children(void *nodep)	96	static bool tmpfs_has_children(void *nodep)
97	{	97	{
98	return ((tmpfs_dentry_t *) nodep)->child != NULL;	98	return ((tmpfs_dentry_t *) nodep)->child != NULL;
99	}	99	}
100		100
101	static void *tmpfs_root_get(dev_handle_t dev_handle)	101	static void *tmpfs_root_get(dev_handle_t dev_handle)
102	{	102	{
103	return root;	103	return root;
104	}	104	}
105		105
106	static char tmpfs_plb_get_char(unsigned pos)	106	static char tmpfs_plb_get_char(unsigned pos)
107	{	107	{
108	return tmpfs_reg.plb_ro[pos % PLB_SIZE];	108	return tmpfs_reg.plb_ro[pos % PLB_SIZE];
109	}	109	}
110		110
111	static bool tmpfs_is_directory(void *nodep)	111	static bool tmpfs_is_directory(void *nodep)
112	{	112	{
113	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;	113	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
114	}	114	}
115		115
116	static bool tmpfs_is_file(void *nodep)	116	static bool tmpfs_is_file(void *nodep)
117	{	117	{
118	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;	118	return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
119	}	119	}
120		120
121	/** libfs operations */	121	/** libfs operations */
122	libfs_ops_t tmpfs_libfs_ops = {	122	libfs_ops_t tmpfs_libfs_ops = {
123	.match = tmpfs_match,	123	.match = tmpfs_match,
124	.node_get = tmpfs_node_get,	124	.node_get = tmpfs_node_get,
125	.node_put = tmpfs_node_put,	125	.node_put = tmpfs_node_put,
126	.create = tmpfs_create_node,	126	.create = tmpfs_create_node,
127	.destroy = tmpfs_destroy_node,	127	.destroy = tmpfs_destroy_node,
128	.link = tmpfs_link_node,	128	.link = tmpfs_link_node,
129	.unlink = tmpfs_unlink_node,	129	.unlink = tmpfs_unlink_node,
130	.index_get = tmpfs_index_get,	130	.index_get = tmpfs_index_get,
131	.size_get = tmpfs_size_get,	131	.size_get = tmpfs_size_get,
132	.lnkcnt_get = tmpfs_lnkcnt_get,	132	.lnkcnt_get = tmpfs_lnkcnt_get,
133	.has_children = tmpfs_has_children,	133	.has_children = tmpfs_has_children,
134	.root_get = tmpfs_root_get,	134	.root_get = tmpfs_root_get,
135	.plb_get_char = tmpfs_plb_get_char,	135	.plb_get_char = tmpfs_plb_get_char,
136	.is_directory = tmpfs_is_directory,	136	.is_directory = tmpfs_is_directory,
137	.is_file = tmpfs_is_file	137	.is_file = tmpfs_is_file
138	};	138	};
139		139
140	/** Hash table of all directory entries. */	140	/** Hash table of all directory entries. */
141	hash_table_t dentries;	141	hash_table_t dentries;
142		142
143	/* Implementation of hash table interface for the dentries hash table. */	143	/* Implementation of hash table interface for the dentries hash table. */
144	static hash_index_t dentries_hash(unsigned long *key)	144	static hash_index_t dentries_hash(unsigned long *key)
145	{	145	{
146	return *key % DENTRIES_BUCKETS;	146	return *key % DENTRIES_BUCKETS;
147	}	147	}
148		148
149	static int dentries_compare(unsigned long *key, hash_count_t keys,	149	static int dentries_compare(unsigned long *key, hash_count_t keys,
150	link_t *item)	150	link_t *item)
151	{	151	{
152	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,	152	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
153	dh_link);	153	dh_link);
154	return dentry->index == *key;	154	return dentry->index == *key;
155	}	155	}
156		156
157	static void dentries_remove_callback(link_t *item)	157	static void dentries_remove_callback(link_t *item)
158	{	158	{
159	}	159	}
160		160
161	/** TMPFS dentries hash table operations. */	161	/** TMPFS dentries hash table operations. */
162	hash_table_operations_t dentries_ops = {	162	hash_table_operations_t dentries_ops = {
163	.hash = dentries_hash,	163	.hash = dentries_hash,
164	.compare = dentries_compare,	164	.compare = dentries_compare,
165	.remove_callback = dentries_remove_callback	165	.remove_callback = dentries_remove_callback
166	};	166	};
167		167
168	fs_index_t tmpfs_next_index = 1;	168	fs_index_t tmpfs_next_index = 1;
169		169
170	typedef struct {	170	typedef struct {
171	char *name;	171	char *name;
172	tmpfs_dentry_t *parent;	172	tmpfs_dentry_t *parent;
173	link_t link;	173	link_t link;
174	} tmpfs_name_t;	174	} tmpfs_name_t;
175		175
176	/* Implementation of hash table interface for the names hash table. */	176	/* Implementation of hash table interface for the names hash table. */
177	static hash_index_t names_hash(unsigned long *key)	177	static hash_index_t names_hash(unsigned long *key)
178	{	178	{
179	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	179	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
180	return dentry->index % NAMES_BUCKETS;	180	return dentry->index % NAMES_BUCKETS;
181	}	181	}
182		182
183	static int names_compare(unsigned long key, hash_count_t keys, link_t item)	183	static int names_compare(unsigned long key, hash_count_t keys, link_t item)
184	{	184	{
185	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;	185	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) *key;
186	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	186	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
187	link);	187	link);
188	return dentry == namep->parent;	188	return dentry == namep->parent;
189	}	189	}
190		190
191	static void names_remove_callback(link_t *item)	191	static void names_remove_callback(link_t *item)
192	{	192	{
193	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,	193	tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
194	link);	194	link);
195	free(namep->name);	195	free(namep->name);
196	free(namep);	196	free(namep);
197	}	197	}
198		198
199	/** TMPFS node names hash table operations. */	199	/** TMPFS node names hash table operations. */
200	static hash_table_operations_t names_ops = {	200	static hash_table_operations_t names_ops = {
201	.hash = names_hash,	201	.hash = names_hash,
202	.compare = names_compare,	202	.compare = names_compare,
203	.remove_callback = names_remove_callback	203	.remove_callback = names_remove_callback
204	};	204	};
205		205
206	static void tmpfs_name_initialize(tmpfs_name_t *namep)	206	static void tmpfs_name_initialize(tmpfs_name_t *namep)
207	{	207	{
208	namep->name = NULL;	208	namep->name = NULL;
209	namep->parent = NULL;	209	namep->parent = NULL;
210	link_initialize(&namep->link);	210	link_initialize(&namep->link);
211	}	211	}
212		212
213	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)	213	static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
214	{	214	{
215	dentry->index = 0;	215	dentry->index = 0;
216	dentry->sibling = NULL;	216	dentry->sibling = NULL;
217	dentry->child = NULL;	217	dentry->child = NULL;
218	dentry->type = TMPFS_NONE;	218	dentry->type = TMPFS_NONE;
219	dentry->lnkcnt = 0;	219	dentry->lnkcnt = 0;
220	dentry->size = 0;	220	dentry->size = 0;
221	dentry->data = NULL;	221	dentry->data = NULL;
222	link_initialize(&dentry->dh_link);	222	link_initialize(&dentry->dh_link);
223	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,	223	return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,
224	&names_ops);	224	&names_ops);
225	}	225	}
226		226
227	static bool tmpfs_init(void)	227	static bool tmpfs_init(void)
228	{	228	{
229	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))	229	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
230	return false;	230	return false;
231	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);	231	root = (tmpfs_dentry_t *) tmpfs_create_node(L_DIRECTORY);
232	if (!root) {	232	if (!root) {
233	hash_table_destroy(&dentries);	233	hash_table_destroy(&dentries);
234	return false;	234	return false;
235	}	235	}
236	root->lnkcnt = 1;	236	root->lnkcnt = 1;
237	return true;	237	return true;
238	}	238	}
239		239
240	/** Compare one component of path to a directory entry.	240	/** Compare one component of path to a directory entry.
241	*	241	*
242	* @param parentp Pointer to node from which we descended.	242	* @param parentp Pointer to node from which we descended.
243	* @param childp Pointer to node to compare the path component with.	243	* @param childp Pointer to node to compare the path component with.
244	* @param component Array of characters holding component name.	244	* @param component Array of characters holding component name.
245	*	245	*
246	* @return True on match, false otherwise.	246	* @return True on match, false otherwise.
247	*/	247	*/
248	static bool	248	static bool
249	tmpfs_match_one(tmpfs_dentry_t parentp, tmpfs_dentry_t childp,	249	tmpfs_match_one(tmpfs_dentry_t parentp, tmpfs_dentry_t childp,
250	const char *component)	250	const char *component)
251	{	251	{
252	unsigned long key = (unsigned long) parentp;	252	unsigned long key = (unsigned long) parentp;
253	link_t *hlp = hash_table_find(&childp->names, &key);	253	link_t *hlp = hash_table_find(&childp->names, &key);
254	assert(hlp);	254	assert(hlp);
255	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);	255	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);
256	return !strcmp(namep->name, component);	256	return !strcmp(namep->name, component);
257	}	257	}
258		258
259	void tmpfs_match(void prnt, const char *component)	259	void tmpfs_match(void prnt, const char *component)
260	{	260	{
261	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	261	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
262	tmpfs_dentry_t *childp = parentp->child;	262	tmpfs_dentry_t *childp = parentp->child;
263		263
264	while (childp && !tmpfs_match_one(parentp, childp, component))	264	while (childp && !tmpfs_match_one(parentp, childp, component))
265	childp = childp->sibling;	265	childp = childp->sibling;
266		266
267	return (void *) childp;	267	return (void *) childp;
268	}	268	}
269		269
270	void *	270	void *
271	tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index)	271	tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index)
272	{	272	{
273	unsigned long key = index;	273	unsigned long key = index;
274	link_t *lnk = hash_table_find(&dentries, &key);	274	link_t *lnk = hash_table_find(&dentries, &key);
275	if (!lnk)	275	if (!lnk)
276	return NULL;	276	return NULL;
277	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);	277	return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);
278	}	278	}
279		279
280	void tmpfs_node_put(void *node)	280	void tmpfs_node_put(void *node)
281	{	281	{
282	/* nothing to do */	282	/* nothing to do */
283	}	283	}
284		284
285	void *tmpfs_create_node(int lflag)	285	void *tmpfs_create_node(int lflag)
286	{	286	{
287	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));	287	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
288		288
289	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));	289	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
290	if (!node)	290	if (!node)
291	return NULL;	291	return NULL;
292		292
293	if (!tmpfs_dentry_initialize(node)) {	293	if (!tmpfs_dentry_initialize(node)) {
294	free(node);	294	free(node);
295	return NULL;	295	return NULL;
296	}	296	}
297	node->index = tmpfs_next_index++;	297	node->index = tmpfs_next_index++;
298	if (lflag & L_DIRECTORY)	298	if (lflag & L_DIRECTORY)
299	node->type = TMPFS_DIRECTORY;	299	node->type = TMPFS_DIRECTORY;
300	else	300	else
301	node->type = TMPFS_FILE;	301	node->type = TMPFS_FILE;
302		302
303	/* Insert the new node into the dentry hash table. */	303	/* Insert the new node into the dentry hash table. */
304	unsigned long key = node->index;	304	unsigned long key = node->index;
305	hash_table_insert(&dentries, &key, &node->dh_link);	305	hash_table_insert(&dentries, &key, &node->dh_link);
306	return (void *) node;	306	return (void *) node;
307	}	307	}
308		308
309	bool tmpfs_link_node(void prnt, void chld, const char *nm)	309	bool tmpfs_link_node(void prnt, void chld, const char *nm)
310	{	310	{
311	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;	311	tmpfs_dentry_t parentp = (tmpfs_dentry_t ) prnt;
312	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;	312	tmpfs_dentry_t childp = (tmpfs_dentry_t ) chld;
313		313
314	assert(parentp->type == TMPFS_DIRECTORY);	314	assert(parentp->type == TMPFS_DIRECTORY);
315		315
316	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));	316	tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));
317	if (!namep)	317	if (!namep)
318	return false;	318	return false;
319	tmpfs_name_initialize(namep);	319	tmpfs_name_initialize(namep);
320	size_t len = strlen(nm);	320	size_t len = strlen(nm);
321	namep->name = malloc(len + 1);	321	namep->name = malloc(len + 1);
322	if (!namep->name) {	322	if (!namep->name) {
323	free(namep);	323	free(namep);
324	return false;	324	return false;
325	}	325	}
326	strcpy(namep->name, nm);	326	strcpy(namep->name, nm);
327	namep->parent = parentp;	327	namep->parent = parentp;
328		328
329	childp->lnkcnt++;	329	childp->lnkcnt++;
330		330
331	unsigned long key = (unsigned long) parentp;	331	unsigned long key = (unsigned long) parentp;
332	hash_table_insert(&childp->names, &key, &namep->link);	332	hash_table_insert(&childp->names, &key, &namep->link);
333		333
334	/* Insert the new node into the namespace. */	334	/* Insert the new node into the namespace. */
335	if (parentp->child) {	335	if (parentp->child) {
336	tmpfs_dentry_t *tmp = parentp->child;	336	tmpfs_dentry_t *tmp = parentp->child;
337	while (tmp->sibling)	337	while (tmp->sibling)
338	tmp = tmp->sibling;	338	tmp = tmp->sibling;
339	tmp->sibling = childp;	339	tmp->sibling = childp;
340	} else {	340	} else {
341	parentp->child = childp;	341	parentp->child = childp;
342	}	342	}
343		343
344	return true;	344	return true;
345	}	345	}
346		346
347	int tmpfs_unlink_node(void prnt, void chld)	347	int tmpfs_unlink_node(void prnt, void chld)
348	{	348	{
349	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;	349	tmpfs_dentry_t parentp = (tmpfs_dentry_t )prnt;
350	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;	350	tmpfs_dentry_t childp = (tmpfs_dentry_t )chld;
351		351
352	if (!parentp)	352	if (!parentp)
353	return EBUSY;	353	return EBUSY;
354		354
355	if (childp->child)	355	if (childp->child)
356	return ENOTEMPTY;	356	return ENOTEMPTY;
357		357
358	if (parentp->child == childp) {	358	if (parentp->child == childp) {
359	parentp->child = childp->sibling;	359	parentp->child = childp->sibling;
360	} else {	360	} else {
361	/* TODO: consider doubly linked list for organizing siblings. */	361	/* TODO: consider doubly linked list for organizing siblings. */
362	tmpfs_dentry_t *tmp = parentp->child;	362	tmpfs_dentry_t *tmp = parentp->child;
363	while (tmp->sibling != childp)	363	while (tmp->sibling != childp)
364	tmp = tmp->sibling;	364	tmp = tmp->sibling;
365	tmp->sibling = childp->sibling;	365	tmp->sibling = childp->sibling;
366	}	366	}
367	childp->sibling = NULL;	367	childp->sibling = NULL;
368		368
369	unsigned long key = (unsigned long) parentp;	369	unsigned long key = (unsigned long) parentp;
370	hash_table_remove(&childp->names, &key, 1);	370	hash_table_remove(&childp->names, &key, 1);
371		371
372	childp->lnkcnt--;	372	childp->lnkcnt--;
373		373
374	return EOK;	374	return EOK;
375	}	375	}
376		376
377	int tmpfs_destroy_node(void *nodep)	377	int tmpfs_destroy_node(void *nodep)
378	{	378	{
379	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;	379	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;
380		380
381	assert(!dentry->lnkcnt);	381	assert(!dentry->lnkcnt);
382	assert(!dentry->child);	382	assert(!dentry->child);
383	assert(!dentry->sibling);	383	assert(!dentry->sibling);
384		384
385	unsigned long key = dentry->index;	385	unsigned long key = dentry->index;
386	hash_table_remove(&dentries, &key, 1);	386	hash_table_remove(&dentries, &key, 1);
387		387
388	hash_table_destroy(&dentry->names);	388	hash_table_destroy(&dentry->names);
389		389
390	if (dentry->type == TMPFS_FILE)	390	if (dentry->type == TMPFS_FILE)
391	free(dentry->data);	391	free(dentry->data);
392	free(dentry);	392	free(dentry);
393	return EOK;	393	return EOK;
394	}	394	}
395		395
-		396	void tmpfs_mount(ipc_callid_t rid, ipc_call_t *request)
-		397	{
-		398	dev_handle_t mr_dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
-		399	fs_index_t mr_index = (fs_index_t)IPC_GET_ARG2(*request);
-		400	fs_handle_t mp_fs_handle = (fs_handle_t)IPC_GET_ARG3(*request);
-		401	dev_handle_t mp_dev_handle = (dev_handle_t)IPC_GET_ARG4(*request);
-		402	fs_index_t mp_index = (fs_index_t)IPC_GET_ARG5(*request);
-		403	if ((mr_index == root->index) &&
-		404	(mp_fs_handle == tmpfs_reg.fs_handle) &&
-		405	(mp_index == mr_index))
-		406	ipc_answer_0(rid, EOK);
-		407	else
-		408	ipc_answer_0(rid, ENOTSUP);
-		409	}
-		410
396	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)	411	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
397	{	412	{
398	/* Initialize TMPFS. */	413	/* Initialize TMPFS. */
399	if (!root && !tmpfs_init()) {	414	if (!root && !tmpfs_init()) {
400	ipc_answer_0(rid, ENOMEM);	415	ipc_answer_0(rid, ENOMEM);
401	return;	416	return;
402	}	417	}
403	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);	418	libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
404	}	419	}
405		420
406	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)	421	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
407	{	422	{
408	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	423	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
409	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	424	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
410	off_t pos = (off_t)IPC_GET_ARG3(*request);	425	off_t pos = (off_t)IPC_GET_ARG3(*request);
411		426
412	/*	427	/*
413	* Lookup the respective dentry.	428	* Lookup the respective dentry.
414	*/	429	*/
415	link_t *hlp;	430	link_t *hlp;
416	unsigned long key = index;	431	unsigned long key = index;
417	hlp = hash_table_find(&dentries, &key);	432	hlp = hash_table_find(&dentries, &key);
418	if (!hlp) {	433	if (!hlp) {
419	ipc_answer_0(rid, ENOENT);	434	ipc_answer_0(rid, ENOENT);
420	return;	435	return;
421	}	436	}
422	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	437	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
423	dh_link);	438	dh_link);
424		439
425	/*	440	/*
426	* Receive the read request.	441	* Receive the read request.
427	*/	442	*/
428	ipc_callid_t callid;	443	ipc_callid_t callid;
429	size_t len;	444	size_t len;
430	if (!ipc_data_read_receive(&callid, &len)) {	445	if (!ipc_data_read_receive(&callid, &len)) {
431	ipc_answer_0(callid, EINVAL);	446	ipc_answer_0(callid, EINVAL);
432	ipc_answer_0(rid, EINVAL);	447	ipc_answer_0(rid, EINVAL);
433	return;	448	return;
434	}	449	}
435		450
436	size_t bytes;	451	size_t bytes;
437	if (dentry->type == TMPFS_FILE) {	452	if (dentry->type == TMPFS_FILE) {
438	bytes = max(0, min(dentry->size - pos, len));	453	bytes = max(0, min(dentry->size - pos, len));
439	(void) ipc_data_read_finalize(callid, dentry->data + pos,	454	(void) ipc_data_read_finalize(callid, dentry->data + pos,
440	bytes);	455	bytes);
441	} else {	456	} else {
442	int i;	457	int i;
443	tmpfs_dentry_t *cur;	458	tmpfs_dentry_t *cur;
444		459
445	assert(dentry->type == TMPFS_DIRECTORY);	460	assert(dentry->type == TMPFS_DIRECTORY);
446		461
447	/*	462	/*
448	* Yes, we really use O(n) algorithm here.	463	* Yes, we really use O(n) algorithm here.
449	* If it bothers someone, it could be fixed by introducing a	464	* If it bothers someone, it could be fixed by introducing a
450	* hash table.	465	* hash table.
451	*/	466	*/
452	for (i = 0, cur = dentry->child; i < pos && cur; i++,	467	for (i = 0, cur = dentry->child; i < pos && cur; i++,
453	cur = cur->sibling)	468	cur = cur->sibling)
454	;	469	;
455		470
456	if (!cur) {	471	if (!cur) {
457	ipc_answer_0(callid, ENOENT);	472	ipc_answer_0(callid, ENOENT);
458	ipc_answer_1(rid, ENOENT, 0);	473	ipc_answer_1(rid, ENOENT, 0);
459	return;	474	return;
460	}	475	}
461		476
462	unsigned long key = (unsigned long) dentry;	477	unsigned long key = (unsigned long) dentry;
463	link_t *hlp = hash_table_find(&cur->names, &key);	478	link_t *hlp = hash_table_find(&cur->names, &key);
464	assert(hlp);	479	assert(hlp);
465	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,	480	tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,
466	link);	481	link);
467		482
468	(void) ipc_data_read_finalize(callid, namep->name,	483	(void) ipc_data_read_finalize(callid, namep->name,
469	strlen(namep->name) + 1);	484	strlen(namep->name) + 1);
470	bytes = 1;	485	bytes = 1;
471	}	486	}
472		487
473	/*	488	/*
474	* Answer the VFS_READ call.	489	* Answer the VFS_READ call.
475	*/	490	*/
476	ipc_answer_1(rid, EOK, bytes);	491	ipc_answer_1(rid, EOK, bytes);
477	}	492	}
478		493
479	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)	494	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
480	{	495	{
481	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);	496	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
482	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);	497	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
483	off_t pos = (off_t)IPC_GET_ARG3(*request);	498	off_t pos = (off_t)IPC_GET_ARG3(*request);
484		499
485	/*	500	/*

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c – Rev 2863 → 2958