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 <dirent.h>
#include <assert.h>
#include <sys/types.h>
#include <libadt/hash_table.h>
#include <as.h>
 
#define min(a, b)       ((a) < (b) ? (a) : (b))
#define max(a, b)       ((a) > (b) ? (a) : (b))
 
#define PLB_GET_CHAR(i)     (tmpfs_reg.plb_ro[(i) % PLB_SIZE])
 
#define DENTRIES_BUCKETS    256
 
#define TMPFS_GET_INDEX(x)  (((tmpfs_dentry_t *)(x))->index)
#define TMPFS_GET_LNKCNT(x) 1
 
/*
 * Hash table of all directory entries.
 */
hash_table_t dentries;
 
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
};
 
unsigned tmpfs_next_index = 1;
 
static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
{
    dentry->index = 0;
    dentry->parent = NULL;
    dentry->sibling = NULL;
    dentry->child = NULL;
    dentry->name = NULL;
    dentry->type = TMPFS_NONE;
    dentry->size = 0;
    dentry->data = NULL;
    link_initialize(&dentry->dh_link);
}
 
/*
 * 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;
 
static bool tmpfs_init(void)
{
    if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
        return false;
 
    root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
    if (!root)
        return false;
    tmpfs_dentry_initialize(root);
    root->index = tmpfs_next_index++;
    root->name = "";
    root->type = TMPFS_DIRECTORY;
    hash_table_insert(&dentries, &root->index, &root->dh_link);
 
    return true;
}
 
/** Compare one component of path to a directory entry.
 *
 * @param nodep     Node to compare the path component with.
 * @param component Array of characters holding component name.
 *
 * @return      True on match, false otherwise.
 */
static bool match_component(void *nodep, const char *component)
{
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
 
    return !strcmp(dentry->name, component);
}
 
static void *create_node(void *nodep,
    const char *component, int lflag)
{
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
 
    assert(dentry->type == TMPFS_DIRECTORY);
    assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
 
    tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
    if (!node)
        return NULL;
    size_t len = strlen(component);
    char *name = malloc(len + 1);
    if (!name) {
        free(node);
        return NULL;
    }
    strcpy(name, component);
 
    tmpfs_dentry_initialize(node);
    node->index = tmpfs_next_index++;
    node->name = name;
    node->parent = dentry;
    if (lflag & L_DIRECTORY)
        node->type = TMPFS_DIRECTORY;
    else
        node->type = TMPFS_FILE;
 
    /* Insert the new node into the namespace. */
    if (dentry->child) {
        tmpfs_dentry_t *tmp = dentry->child;
        while (tmp->sibling)
            tmp = tmp->sibling;
        tmp->sibling = node;
    } else {
        dentry->child = node;
    }
 
    /* Insert the new node into the dentry hash table. */
    hash_table_insert(&dentries, &node->index, &node->dh_link);
    return (void *) node;
}
 
static int destroy_component(void *nodeptr)
{
    return EPERM;
}
 
void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    unsigned next = IPC_GET_ARG1(*request);
    unsigned last = IPC_GET_ARG2(*request);
    int dev_handle = IPC_GET_ARG3(*request);
    int lflag = IPC_GET_ARG4(*request);
 
    if (last < next)
        last += PLB_SIZE;
 
    /*
     * Initialize TMPFS.
     */
    if (!root && !tmpfs_init()) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
 
    tmpfs_dentry_t *dtmp = root->child;
    tmpfs_dentry_t *dcur = root;
 
    if (PLB_GET_CHAR(next) == '/')
        next++;     /* eat slash */
   
    char component[NAME_MAX + 1];
    int len = 0;
    while (dtmp && next <= last) {
 
        /* collect the component */
        if (PLB_GET_CHAR(next) != '/') {
            if (len + 1 == NAME_MAX) {
                /* comopnent length overflow */
                ipc_answer_0(rid, ENAMETOOLONG);
                return;
            }
            component[len++] = PLB_GET_CHAR(next);
            next++; /* process next character */
            if (next <= last)
                continue;
        }
 
        assert(len);
        component[len] = '\0';
        next++;     /* eat slash */
        len = 0;
 
        /* match the component */
        while (dtmp && !match_component(dtmp, component))
            dtmp = dtmp->sibling;
 
        /* handle miss: match amongst siblings */
        if (!dtmp) {
            if ((next > last) && (lflag & L_CREATE)) {
                /* no components left and L_CREATE specified */
                if (dcur->type != TMPFS_DIRECTORY) {
                    ipc_answer_0(rid, ENOTDIR);
                    return;
                }
                void *nodep = create_node(dcur,
                    component, lflag);
                if (nodep) {
                    ipc_answer_5(rid, EOK,
                        tmpfs_reg.fs_handle, dev_handle,
                        TMPFS_GET_INDEX(nodep), 0,
                        TMPFS_GET_LNKCNT(nodep));
                } else {
                    ipc_answer_0(rid, ENOSPC);
                }
                return;
            }
            ipc_answer_0(rid, ENOENT);
            return;
        }
 
        /* descend one level */
        dcur = dtmp;
        dtmp = dtmp->child;
    }
 
    /* handle miss: excessive components */
    if (!dtmp && next <= last) {
        if (lflag & L_CREATE) {
            if (dcur->type != TMPFS_DIRECTORY) {
                ipc_answer_0(rid, ENOTDIR);
                return;
            }
 
            /* collect next component */
            while (next <= last) {
                if (PLB_GET_CHAR(next) == '/') {
                    /* more than one component */
                    ipc_answer_0(rid, ENOENT);
                    return;
                }
                if (len + 1 == NAME_MAX) {
                    /* component length overflow */
                    ipc_answer_0(rid, ENAMETOOLONG);
                    return;
                }
                component[len++] = PLB_GET_CHAR(next);
                next++; /* process next character */
            }
            assert(len);
            component[len] = '\0';
            len = 0;
               
 
            void *nodep = create_node(dcur, component, lflag);
            if (nodep) {
                ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle,
                    dev_handle, TMPFS_GET_INDEX(nodep), 0,
                    TMPFS_GET_LNKCNT(nodep));
            } else {
                ipc_answer_0(rid, ENOSPC);
            }
            return;
        }
        ipc_answer_0(rid, ENOENT);
        return;
    }
 
    /* handle hit */
    if (lflag & L_DESTROY) {
        int res = destroy_component(dcur);
        ipc_answer_0(rid, res);
        return;
    }
    if ((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) {
        ipc_answer_0(rid, EEXIST);
        return;
    }
    if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {
        ipc_answer_0(rid, EISDIR);
        return;
    }
    if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {
        ipc_answer_0(rid, ENOTDIR);
        return;
    }
 
    ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
        dcur->size, TMPFS_GET_LNKCNT(dcur));
}
 
void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
{
    int dev_handle = IPC_GET_ARG1(*request);
    unsigned long index = IPC_GET_ARG2(*request);
    off_t pos = IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    hlp = hash_table_find(&dentries, &index);
    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 = dentry->child;
       
        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;
        }
 
        (void) ipc_data_read_finalize(callid, cur->name,
            strlen(cur->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)
{
    int dev_handle = IPC_GET_ARG1(*request);
    unsigned long index = IPC_GET_ARG2(*request);
    off_t pos = IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    hlp = hash_table_find(&dentries, &index);
    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)
{
    int dev_handle = IPC_GET_ARG1(*request);
    unsigned long index = IPC_GET_ARG2(*request);
    size_t size = IPC_GET_ARG3(*request);
 
    /*
     * Lookup the respective dentry.
     */
    link_t *hlp;
    hlp = hash_table_find(&dentries, &index);
    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);
}
 
/**
 * @}
 */
 

Rev 2728	Rev 2730
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 <dirent.h>	48	#include <dirent.h>
49	#include <assert.h>	49	#include <assert.h>
50	#include <sys/types.h>	50	#include <sys/types.h>
51	#include <libadt/hash_table.h>	51	#include <libadt/hash_table.h>
52	#include <as.h>	52	#include <as.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 PLB_GET_CHAR(i) (tmpfs_reg.plb_ro[(i) % PLB_SIZE])	57	#define PLB_GET_CHAR(i) (tmpfs_reg.plb_ro[(i) % PLB_SIZE])
58		58
59	#define DENTRIES_BUCKETS 256	59	#define DENTRIES_BUCKETS 256
60		60
-		61	#define TMPFS_GET_INDEX(x) (((tmpfs_dentry_t *)(x))->index)
-		62	#define TMPFS_GET_LNKCNT(x) 1
-		63
61	/*	64	/*
62	* Hash table of all directory entries.	65	* Hash table of all directory entries.
63	*/	66	*/
64	hash_table_t dentries;	67	hash_table_t dentries;
65		68
66	static hash_index_t dentries_hash(unsigned long *key)	69	static hash_index_t dentries_hash(unsigned long *key)
67	{	70	{
68	return *key % DENTRIES_BUCKETS;	71	return *key % DENTRIES_BUCKETS;
69	}	72	}
70		73
71	static int dentries_compare(unsigned long *key, hash_count_t keys,	74	static int dentries_compare(unsigned long *key, hash_count_t keys,
72	link_t *item)	75	link_t *item)
73	{	76	{
74	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,	77	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
75	dh_link);	78	dh_link);
76	return dentry->index == *key;	79	return dentry->index == *key;
77	}	80	}
78		81
79	static void dentries_remove_callback(link_t *item)	82	static void dentries_remove_callback(link_t *item)
80	{	83	{
81	}	84	}
82		85
83	/** TMPFS dentries hash table operations. */	86	/** TMPFS dentries hash table operations. */
84	hash_table_operations_t dentries_ops = {	87	hash_table_operations_t dentries_ops = {
85	.hash = dentries_hash,	88	.hash = dentries_hash,
86	.compare = dentries_compare,	89	.compare = dentries_compare,
87	.remove_callback = dentries_remove_callback	90	.remove_callback = dentries_remove_callback
88	};	91	};
89		92
90	unsigned tmpfs_next_index = 1;	93	unsigned tmpfs_next_index = 1;
91		94
92	static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)	95	static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
93	{	96	{
94	dentry->index = 0;	97	dentry->index = 0;
95	dentry->parent = NULL;	98	dentry->parent = NULL;
96	dentry->sibling = NULL;	99	dentry->sibling = NULL;
97	dentry->child = NULL;	100	dentry->child = NULL;
98	dentry->name = NULL;	101	dentry->name = NULL;
99	dentry->type = TMPFS_NONE;	102	dentry->type = TMPFS_NONE;
100	dentry->size = 0;	103	dentry->size = 0;
101	dentry->data = NULL;	104	dentry->data = NULL;
102	link_initialize(&dentry->dh_link);	105	link_initialize(&dentry->dh_link);
103	}	106	}
104		107
105	/*	108	/*
106	* For now, we don't distinguish between different dev_handles/instances. All	109	* For now, we don't distinguish between different dev_handles/instances. All
107	* requests resolve to the only instance, rooted in the following variable.	110	* requests resolve to the only instance, rooted in the following variable.
108	*/	111	*/
109	static tmpfs_dentry_t *root;	112	static tmpfs_dentry_t *root;
110		113
111	static bool tmpfs_init(void)	114	static bool tmpfs_init(void)
112	{	115	{
113	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))	116	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
114	return false;	117	return false;
115		118
116	root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	119	root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
117	if (!root)	120	if (!root)
118	return false;	121	return false;
119	tmpfs_dentry_initialize(root);	122	tmpfs_dentry_initialize(root);
120	root->index = tmpfs_next_index++;	123	root->index = tmpfs_next_index++;
121	root->name = "";	124	root->name = "";
122	root->type = TMPFS_DIRECTORY;	125	root->type = TMPFS_DIRECTORY;
123	hash_table_insert(&dentries, &root->index, &root->dh_link);	126	hash_table_insert(&dentries, &root->index, &root->dh_link);
124		127
125	return true;	128	return true;
126	}	129	}
127		130
128	/** Compare one component of path to a directory entry.	131	/** Compare one component of path to a directory entry.
129	*	132	*
130	* @param dentry Directory entry to compare the path component with.	133	* @param nodep Node to compare the path component with.
131	* @param component Array of characters holding component name.	134	* @param component Array of characters holding component name.
132	*	135	*
133	* @return True on match, false otherwise.	136	* @return True on match, false otherwise.
134	*/	137	*/
135	static bool match_component(tmpfs_dentry_t dentry, const char component)	138	static bool match_component(void nodep, const char component)
136	{	139	{
-		140	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;
-		141
137	return !strcmp(dentry->name, component);	142	return !strcmp(dentry->name, component);
138	}	143	}
139		144
140	static unsigned long create_node(tmpfs_dentry_t *dentry,	145	static void create_node(void nodep,
141	const char *component, int lflag)	146	const char *component, int lflag)
142	{	147	{
-		148	tmpfs_dentry_t dentry = (tmpfs_dentry_t ) nodep;
-		149
143	assert(dentry->type == TMPFS_DIRECTORY);	150	assert(dentry->type == TMPFS_DIRECTORY);
144	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));	151	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
145		152
146	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));	153	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
147	if (!node)	154	if (!node)
148	return 0;	155	return NULL;
149	size_t len = strlen(component);	156	size_t len = strlen(component);
150	char *name = malloc(len + 1);	157	char *name = malloc(len + 1);
151	if (!name) {	158	if (!name) {
152	free(node);	159	free(node);
153	return 0;	160	return NULL;
154	}	161	}
155	strcpy(name, component);	162	strcpy(name, component);
156		163
157	tmpfs_dentry_initialize(node);	164	tmpfs_dentry_initialize(node);
158	node->index = tmpfs_next_index++;	165	node->index = tmpfs_next_index++;
159	node->name = name;	166	node->name = name;
160	node->parent = dentry;	167	node->parent = dentry;
161	if (lflag & L_DIRECTORY)	168	if (lflag & L_DIRECTORY)
162	node->type = TMPFS_DIRECTORY;	169	node->type = TMPFS_DIRECTORY;
163	else	170	else
164	node->type = TMPFS_FILE;	171	node->type = TMPFS_FILE;
165		172
166	/* Insert the new node into the namespace. */	173	/* Insert the new node into the namespace. */
167	if (dentry->child) {	174	if (dentry->child) {
168	tmpfs_dentry_t *tmp = dentry->child;	175	tmpfs_dentry_t *tmp = dentry->child;
169	while (tmp->sibling)	176	while (tmp->sibling)
170	tmp = tmp->sibling;	177	tmp = tmp->sibling;
171	tmp->sibling = node;	178	tmp->sibling = node;
172	} else {	179	} else {
173	dentry->child = node;	180	dentry->child = node;
174	}	181	}
175		182
176	/* Insert the new node into the dentry hash table. */	183	/* Insert the new node into the dentry hash table. */
177	hash_table_insert(&dentries, &node->index, &node->dh_link);	184	hash_table_insert(&dentries, &node->index, &node->dh_link);
178	return node->index;	185	return (void *) node;
179	}	186	}
180		187
181	static int destroy_component(tmpfs_dentry_t *dentry)	188	static int destroy_component(void *nodeptr)
182	{	189	{
183	return EPERM;	190	return EPERM;
184	}	191	}
185		192
186	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)	193	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
187	{	194	{
188	unsigned next = IPC_GET_ARG1(*request);	195	unsigned next = IPC_GET_ARG1(*request);
189	unsigned last = IPC_GET_ARG2(*request);	196	unsigned last = IPC_GET_ARG2(*request);
190	int dev_handle = IPC_GET_ARG3(*request);	197	int dev_handle = IPC_GET_ARG3(*request);
191	int lflag = IPC_GET_ARG4(*request);	198	int lflag = IPC_GET_ARG4(*request);
192		199
193	if (last < next)	200	if (last < next)
194	last += PLB_SIZE;	201	last += PLB_SIZE;
195		202
196	/*	203	/*
197	* Initialize TMPFS.	204	* Initialize TMPFS.
198	*/	205	*/
199	if (!root && !tmpfs_init()) {	206	if (!root && !tmpfs_init()) {
200	ipc_answer_0(rid, ENOMEM);	207	ipc_answer_0(rid, ENOMEM);
201	return;	208	return;
202	}	209	}
203		210
204	tmpfs_dentry_t *dtmp = root->child;	211	tmpfs_dentry_t *dtmp = root->child;
205	tmpfs_dentry_t *dcur = root;	212	tmpfs_dentry_t *dcur = root;
206		213
207	if (PLB_GET_CHAR(next) == '/')	214	if (PLB_GET_CHAR(next) == '/')
208	next++; /* eat slash */	215	next++; /* eat slash */
209		216
210	char component[NAME_MAX + 1];	217	char component[NAME_MAX + 1];
211	int len = 0;	218	int len = 0;
212	while (dtmp && next <= last) {	219	while (dtmp && next <= last) {
213		220
214	/* collect the component */	221	/* collect the component */
215	if (PLB_GET_CHAR(next) != '/') {	222	if (PLB_GET_CHAR(next) != '/') {
216	if (len + 1 == NAME_MAX) {	223	if (len + 1 == NAME_MAX) {
217	/* comopnent length overflow */	224	/* comopnent length overflow */
218	ipc_answer_0(rid, ENAMETOOLONG);	225	ipc_answer_0(rid, ENAMETOOLONG);
219	return;	226	return;
220	}	227	}
221	component[len++] = PLB_GET_CHAR(next);	228	component[len++] = PLB_GET_CHAR(next);
222	next++; /* process next character */	229	next++; /* process next character */
223	if (next <= last)	230	if (next <= last)
224	continue;	231	continue;
225	}	232	}
226		233
227	assert(len);	234	assert(len);
228	component[len] = '\0';	235	component[len] = '\0';
229	next++; /* eat slash */	236	next++; /* eat slash */
230	len = 0;	237	len = 0;
231		238
232	/* match the component */	239	/* match the component */
233	while (dtmp && !match_component(dtmp, component))	240	while (dtmp && !match_component(dtmp, component))
234	dtmp = dtmp->sibling;	241	dtmp = dtmp->sibling;
235		242
236	/* handle miss: match amongst siblings */	243	/* handle miss: match amongst siblings */
237	if (!dtmp) {	244	if (!dtmp) {
238	if ((next > last) && (lflag & L_CREATE)) {	245	if ((next > last) && (lflag & L_CREATE)) {
239	/* no components left and L_CREATE specified */	246	/* no components left and L_CREATE specified */
240	if (dcur->type != TMPFS_DIRECTORY) {	247	if (dcur->type != TMPFS_DIRECTORY) {
241	ipc_answer_0(rid, ENOTDIR);	248	ipc_answer_0(rid, ENOTDIR);
242	return;	249	return;
243	}	250	}
244	unsigned long index = create_node(dcur,	251	void *nodep = create_node(dcur,
245	component, lflag);	252	component, lflag);
246	if (index > 0) {	253	if (nodep) {
247	ipc_answer_4(rid, EOK,	254	ipc_answer_5(rid, EOK,
248	tmpfs_reg.fs_handle, dev_handle,	255	tmpfs_reg.fs_handle, dev_handle,
249	index, 0);	256	TMPFS_GET_INDEX(nodep), 0,
-		257	TMPFS_GET_LNKCNT(nodep));
250	} else {	258	} else {
251	ipc_answer_0(rid, ENOSPC);	259	ipc_answer_0(rid, ENOSPC);
252	}	260	}
253	return;	261	return;
254	}	262	}
255	ipc_answer_0(rid, ENOENT);	263	ipc_answer_0(rid, ENOENT);
256	return;	264	return;
257	}	265	}
258		266
259	/* descend one level */	267	/* descend one level */
260	dcur = dtmp;	268	dcur = dtmp;
261	dtmp = dtmp->child;	269	dtmp = dtmp->child;
262	}	270	}
263		271
264	/* handle miss: excessive components */	272	/* handle miss: excessive components */
265	if (!dtmp && next <= last) {	273	if (!dtmp && next <= last) {
266	if (lflag & L_CREATE) {	274	if (lflag & L_CREATE) {
267	if (dcur->type != TMPFS_DIRECTORY) {	275	if (dcur->type != TMPFS_DIRECTORY) {
268	ipc_answer_0(rid, ENOTDIR);	276	ipc_answer_0(rid, ENOTDIR);
269	return;	277	return;
270	}	278	}
271		279
272	/* collect next component */	280	/* collect next component */
273	while (next <= last) {	281	while (next <= last) {
274	if (PLB_GET_CHAR(next) == '/') {	282	if (PLB_GET_CHAR(next) == '/') {
275	/* more than one component */	283	/* more than one component */
276	ipc_answer_0(rid, ENOENT);	284	ipc_answer_0(rid, ENOENT);
277	return;	285	return;
278	}	286	}
279	if (len + 1 == NAME_MAX) {	287	if (len + 1 == NAME_MAX) {
280	/* component length overflow */	288	/* component length overflow */
281	ipc_answer_0(rid, ENAMETOOLONG);	289	ipc_answer_0(rid, ENAMETOOLONG);
282	return;	290	return;
283	}	291	}
284	component[len++] = PLB_GET_CHAR(next);	292	component[len++] = PLB_GET_CHAR(next);
285	next++; /* process next character */	293	next++; /* process next character */
286	}	294	}
287	assert(len);	295	assert(len);
288	component[len] = '\0';	296	component[len] = '\0';
289	len = 0;	297	len = 0;
290		298
291	unsigned long index;	-
292	index = create_node(dcur, component, lflag);	299	void *nodep = create_node(dcur, component, lflag);
293	if (index) {	300	if (nodep) {
294	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle,	301	ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle,
295	dev_handle, index, 0);	302	dev_handle, TMPFS_GET_INDEX(nodep), 0,
-		303	TMPFS_GET_LNKCNT(nodep));
296	} else {	304	} else {
297	ipc_answer_0(rid, ENOSPC);	305	ipc_answer_0(rid, ENOSPC);
298	}	306	}
299	return;	307	return;
300	}	308	}
301	ipc_answer_0(rid, ENOENT);	309	ipc_answer_0(rid, ENOENT);
302	return;	310	return;
303	}	311	}
304		312
305	/* handle hit */	313	/* handle hit */
306	if (lflag & L_DESTROY) {	314	if (lflag & L_DESTROY) {
307	int res = destroy_component(dcur);	315	int res = destroy_component(dcur);
308	ipc_answer_0(rid, res);	316	ipc_answer_0(rid, res);
309	return;	317	return;
310	}	318	}
311	if ((lflag & (L_CREATE \| L_EXCLUSIVE)) == (L_CREATE \| L_EXCLUSIVE)) {	319	if ((lflag & (L_CREATE \| L_EXCLUSIVE)) == (L_CREATE \| L_EXCLUSIVE)) {
312	ipc_answer_0(rid, EEXIST);	320	ipc_answer_0(rid, EEXIST);
313	return;	321	return;
314	}	322	}
315	if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {	323	if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {
316	ipc_answer_0(rid, EISDIR);	324	ipc_answer_0(rid, EISDIR);
317	return;	325	return;
318	}	326	}
319	if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {	327	if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {
320	ipc_answer_0(rid, ENOTDIR);	328	ipc_answer_0(rid, ENOTDIR);
321	return;	329	return;
322	}	330	}
323		331
324	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,	332	ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
325	dcur->size);	333	dcur->size, TMPFS_GET_LNKCNT(dcur));
326	}	334	}
327		335
328	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)	336	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
329	{	337	{
330	int dev_handle = IPC_GET_ARG1(*request);	338	int dev_handle = IPC_GET_ARG1(*request);
331	unsigned long index = IPC_GET_ARG2(*request);	339	unsigned long index = IPC_GET_ARG2(*request);
332	off_t pos = IPC_GET_ARG3(*request);	340	off_t pos = IPC_GET_ARG3(*request);
333		341
334	/*	342	/*
335	* Lookup the respective dentry.	343	* Lookup the respective dentry.
336	*/	344	*/
337	link_t *hlp;	345	link_t *hlp;
338	hlp = hash_table_find(&dentries, &index);	346	hlp = hash_table_find(&dentries, &index);
339	if (!hlp) {	347	if (!hlp) {
340	ipc_answer_0(rid, ENOENT);	348	ipc_answer_0(rid, ENOENT);
341	return;	349	return;
342	}	350	}
343	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	351	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
344	dh_link);	352	dh_link);
345		353
346	/*	354	/*
347	* Receive the read request.	355	* Receive the read request.
348	*/	356	*/
349	ipc_callid_t callid;	357	ipc_callid_t callid;
350	size_t len;	358	size_t len;
351	if (!ipc_data_read_receive(&callid, &len)) {	359	if (!ipc_data_read_receive(&callid, &len)) {
352	ipc_answer_0(callid, EINVAL);	360	ipc_answer_0(callid, EINVAL);
353	ipc_answer_0(rid, EINVAL);	361	ipc_answer_0(rid, EINVAL);
354	return;	362	return;
355	}	363	}
356		364
357	size_t bytes;	365	size_t bytes;
358	if (dentry->type == TMPFS_FILE) {	366	if (dentry->type == TMPFS_FILE) {
359	bytes = max(0, min(dentry->size - pos, len));	367	bytes = max(0, min(dentry->size - pos, len));
360	(void) ipc_data_read_finalize(callid, dentry->data + pos,	368	(void) ipc_data_read_finalize(callid, dentry->data + pos,
361	bytes);	369	bytes);
362	} else {	370	} else {
363	int i;	371	int i;
364	tmpfs_dentry_t *cur = dentry->child;	372	tmpfs_dentry_t *cur = dentry->child;
365		373
366	assert(dentry->type == TMPFS_DIRECTORY);	374	assert(dentry->type == TMPFS_DIRECTORY);
367		375
368	/*	376	/*
369	* Yes, we really use O(n) algorithm here.	377	* Yes, we really use O(n) algorithm here.
370	* If it bothers someone, it could be fixed by introducing a	378	* If it bothers someone, it could be fixed by introducing a
371	* hash table.	379	* hash table.
372	*/	380	*/
373	for (i = 0, cur = dentry->child; i < pos && cur; i++,	381	for (i = 0, cur = dentry->child; i < pos && cur; i++,
374	cur = cur->sibling)	382	cur = cur->sibling)
375	;	383	;
376		384
377	if (!cur) {	385	if (!cur) {
378	ipc_answer_0(callid, ENOENT);	386	ipc_answer_0(callid, ENOENT);
379	ipc_answer_1(rid, ENOENT, 0);	387	ipc_answer_1(rid, ENOENT, 0);
380	return;	388	return;
381	}	389	}
382		390
383	(void) ipc_data_read_finalize(callid, cur->name,	391	(void) ipc_data_read_finalize(callid, cur->name,
384	strlen(cur->name) + 1);	392	strlen(cur->name) + 1);
385	bytes = 1;	393	bytes = 1;
386	}	394	}
387		395
388	/*	396	/*
389	* Answer the VFS_READ call.	397	* Answer the VFS_READ call.
390	*/	398	*/
391	ipc_answer_1(rid, EOK, bytes);	399	ipc_answer_1(rid, EOK, bytes);
392	}	400	}
393		401
394	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)	402	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
395	{	403	{
396	int dev_handle = IPC_GET_ARG1(*request);	404	int dev_handle = IPC_GET_ARG1(*request);
397	unsigned long index = IPC_GET_ARG2(*request);	405	unsigned long index = IPC_GET_ARG2(*request);
398	off_t pos = IPC_GET_ARG3(*request);	406	off_t pos = IPC_GET_ARG3(*request);
399		407
400	/*	408	/*
401	* Lookup the respective dentry.	409	* Lookup the respective dentry.
402	*/	410	*/
403	link_t *hlp;	411	link_t *hlp;
404	hlp = hash_table_find(&dentries, &index);	412	hlp = hash_table_find(&dentries, &index);
405	if (!hlp) {	413	if (!hlp) {
406	ipc_answer_0(rid, ENOENT);	414	ipc_answer_0(rid, ENOENT);
407	return;	415	return;
408	}	416	}
409	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	417	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
410	dh_link);	418	dh_link);
411		419
412	/*	420	/*
413	* Receive the write request.	421	* Receive the write request.
414	*/	422	*/
415	ipc_callid_t callid;	423	ipc_callid_t callid;
416	size_t len;	424	size_t len;
417	if (!ipc_data_write_receive(&callid, &len)) {	425	if (!ipc_data_write_receive(&callid, &len)) {
418	ipc_answer_0(callid, EINVAL);	426	ipc_answer_0(callid, EINVAL);
419	ipc_answer_0(rid, EINVAL);	427	ipc_answer_0(rid, EINVAL);
420	return;	428	return;
421	}	429	}
422		430
423	/*	431	/*
424	* Check whether the file needs to grow.	432	* Check whether the file needs to grow.
425	*/	433	*/
426	if (pos + len <= dentry->size) {	434	if (pos + len <= dentry->size) {
427	/* The file size is not changing. */	435	/* The file size is not changing. */
428	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);	436	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);
429	ipc_answer_2(rid, EOK, len, dentry->size);	437	ipc_answer_2(rid, EOK, len, dentry->size);
430	return;	438	return;
431	}	439	}
432	size_t delta = (pos + len) - dentry->size;	440	size_t delta = (pos + len) - dentry->size;
433	/*	441	/*
434	* At this point, we are deliberately extremely straightforward and	442	* At this point, we are deliberately extremely straightforward and
435	* simply realloc the contents of the file on every write that grows the	443	* simply realloc the contents of the file on every write that grows the
436	* file. In the end, the situation might not be as bad as it may look:	444	* file. In the end, the situation might not be as bad as it may look:
437	* our heap allocator can save us and just grow the block whenever	445	* our heap allocator can save us and just grow the block whenever
438	* possible.	446	* possible.
439	*/	447	*/
440	void *newdata = realloc(dentry->data, dentry->size + delta);	448	void *newdata = realloc(dentry->data, dentry->size + delta);
441	if (!newdata) {	449	if (!newdata) {
442	ipc_answer_0(callid, ENOMEM);	450	ipc_answer_0(callid, ENOMEM);
443	ipc_answer_2(rid, EOK, 0, dentry->size);	451	ipc_answer_2(rid, EOK, 0, dentry->size);
444	return;	452	return;
445	}	453	}
446	/* Clear any newly allocated memory in order to emulate gaps. */	454	/* Clear any newly allocated memory in order to emulate gaps. */
447	memset(newdata + dentry->size, 0, delta);	455	memset(newdata + dentry->size, 0, delta);
448	dentry->size += delta;	456	dentry->size += delta;
449	dentry->data = newdata;	457	dentry->data = newdata;
450	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);	458	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);
451	ipc_answer_2(rid, EOK, len, dentry->size);	459	ipc_answer_2(rid, EOK, len, dentry->size);
452	}	460	}
453		461
454	void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request)	462	void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request)
455	{	463	{
456	int dev_handle = IPC_GET_ARG1(*request);	464	int dev_handle = IPC_GET_ARG1(*request);
457	unsigned long index = IPC_GET_ARG2(*request);	465	unsigned long index = IPC_GET_ARG2(*request);
458	size_t size = IPC_GET_ARG3(*request);	466	size_t size = IPC_GET_ARG3(*request);
459		467
460	/*	468	/*
461	* Lookup the respective dentry.	469	* Lookup the respective dentry.
462	*/	470	*/
463	link_t *hlp;	471	link_t *hlp;
464	hlp = hash_table_find(&dentries, &index);	472	hlp = hash_table_find(&dentries, &index);
465	if (!hlp) {	473	if (!hlp) {
466	ipc_answer_0(rid, ENOENT);	474	ipc_answer_0(rid, ENOENT);
467	return;	475	return;
468	}	476	}
469	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	477	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
470	dh_link);	478	dh_link);
471		479
472	if (size == dentry->size) {	480	if (size == dentry->size) {
473	ipc_answer_0(rid, EOK);	481	ipc_answer_0(rid, EOK);
474	return;	482	return;
475	}	483	}
476		484
477	void *newdata = realloc(dentry->data, size);	485	void *newdata = realloc(dentry->data, size);
478	if (!newdata) {	486	if (!newdata) {
479	ipc_answer_0(rid, ENOMEM);	487	ipc_answer_0(rid, ENOMEM);
480	return;	488	return;
481	}	489	}
482	if (size > dentry->size) {	490	if (size > dentry->size) {
483	size_t delta = size - dentry->size;	491	size_t delta = size - dentry->size;
484	memset(newdata + dentry->size, 0, delta);	492	memset(newdata + dentry->size, 0, delta);
485	}	493	}
486	dentry->size = size;	494	dentry->size = size;
487	dentry->data = newdata;	495	dentry->data = newdata;
488	ipc_answer_0(rid, EOK);	496	ipc_answer_0(rid, EOK);
489	}	497	}
490		498
491	/**	499	/**

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(root)/trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c @ 4717 – Rev 2728 → 2730