WebSVN – HelenOS – Diff – /branches/dynload/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
 
/*
 * 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 dentry    Directory entry to compare the path component with.
 * @param component Array of characters holding component name.
 *
 * @return      True on match, false otherwise.
 */
static bool match_component(tmpfs_dentry_t *dentry, const char *component)
{
    return !strcmp(dentry->name, component);
}
 
static unsigned long create_node(tmpfs_dentry_t *dentry,
    const char *component, int lflag)
{
    assert(dentry->type == TMPFS_DIRECTORY);
    assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
 
    tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
    if (!node)
        return 0;
    size_t len = strlen(component);
    char *name = malloc(len + 1);
    if (!name) {
        free(node);
        return 0;
    }
    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 node->index;
}
 
static int destroy_component(tmpfs_dentry_t *dentry)
{
    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;
                }
                unsigned long index = create_node(dcur,
                    component, lflag);
                if (index > 0) {
                    ipc_answer_4(rid, EOK,
                        tmpfs_reg.fs_handle, dev_handle,
                        index, 0);
                } else {
                    ipc_answer_0(rid, ENOSPC);
                }
                return;
            }
            ipc_answer_0(rid, ENOENT);
            return;
        }
 
        /* descent 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;
               
            unsigned long index;
            index = create_node(dcur, component, lflag);
            if (index) {
                ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle,
                    dev_handle, index, 0);
            } 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_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
        dcur->size);
}
 
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 2710	Rev 2711
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	/*	61	/*
62	* Hash table of all directory entries.	62	* Hash table of all directory entries.
63	*/	63	*/
64	hash_table_t dentries;	64	hash_table_t dentries;
65		65
66	static hash_index_t dentries_hash(unsigned long *key)	66	static hash_index_t dentries_hash(unsigned long *key)
67	{	67	{
68	return *key % DENTRIES_BUCKETS;	68	return *key % DENTRIES_BUCKETS;
69	}	69	}
70		70
71	static int dentries_compare(unsigned long *key, hash_count_t keys,	71	static int dentries_compare(unsigned long *key, hash_count_t keys,
72	link_t *item)	72	link_t *item)
73	{	73	{
74	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,	74	tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
75	dh_link);	75	dh_link);
76	return dentry->index == *key;	76	return dentry->index == *key;
77	}	77	}
78		78
79	static void dentries_remove_callback(link_t *item)	79	static void dentries_remove_callback(link_t *item)
80	{	80	{
81	}	81	}
82		82
83	/** TMPFS dentries hash table operations. */	83	/** TMPFS dentries hash table operations. */
84	hash_table_operations_t dentries_ops = {	84	hash_table_operations_t dentries_ops = {
85	.hash = dentries_hash,	85	.hash = dentries_hash,
86	.compare = dentries_compare,	86	.compare = dentries_compare,
87	.remove_callback = dentries_remove_callback	87	.remove_callback = dentries_remove_callback
88	};	88	};
89		89
90	unsigned tmpfs_next_index = 1;	90	unsigned tmpfs_next_index = 1;
91		91
92	static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)	92	static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
93	{	93	{
94	dentry->index = 0;	94	dentry->index = 0;
95	dentry->parent = NULL;	95	dentry->parent = NULL;
96	dentry->sibling = NULL;	96	dentry->sibling = NULL;
97	dentry->child = NULL;	97	dentry->child = NULL;
98	dentry->name = NULL;	98	dentry->name = NULL;
99	dentry->type = TMPFS_NONE;	99	dentry->type = TMPFS_NONE;
100	dentry->size = 0;	100	dentry->size = 0;
101	dentry->data = NULL;	101	dentry->data = NULL;
102	link_initialize(&dentry->dh_link);	102	link_initialize(&dentry->dh_link);
103	}	103	}
104		104
105	/*	105	/*
106	* For now, we don't distinguish between different dev_handles/instances. All	106	* For now, we don't distinguish between different dev_handles/instances. All
107	* requests resolve to the only instance, rooted in the following variable.	107	* requests resolve to the only instance, rooted in the following variable.
108	*/	108	*/
109	static tmpfs_dentry_t *root;	109	static tmpfs_dentry_t *root;
110		110
111	static bool tmpfs_init(void)	111	static bool tmpfs_init(void)
112	{	112	{
113	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))	113	if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
114	return false;	114	return false;
115		115
116	root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	116	root = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));
117	if (!root)	117	if (!root)
118	return false;	118	return false;
119	tmpfs_dentry_initialize(root);	119	tmpfs_dentry_initialize(root);
120	root->index = tmpfs_next_index++;	120	root->index = tmpfs_next_index++;
121	root->name = "";	121	root->name = "";
122	root->type = TMPFS_DIRECTORY;	122	root->type = TMPFS_DIRECTORY;
123	hash_table_insert(&dentries, &root->index, &root->dh_link);	123	hash_table_insert(&dentries, &root->index, &root->dh_link);
124		124
125	/*	-
126	* This is only for debugging. Once we can create files and directories	-
127	* using VFS, we can get rid of this.	-
128	*/	-
129	tmpfs_dentry_t *d;	-
130	d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	-
131	if (!d) {	-
132	free(root);	-
133	root = NULL;	-
134	return false;	-
135	}	-
136	tmpfs_dentry_initialize(d);	-
137	d->index = tmpfs_next_index++;	-
138	root->child = d;	-
139	d->parent = root;	-
140	d->type = TMPFS_DIRECTORY;	-
141	d->name = "dir1";	-
142	hash_table_insert(&dentries, &d->index, &d->dh_link);	-
143		-
144	d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	-
145	if (!d) {	-
146	free(root->child);	-
147	free(root);	-
148	root = NULL;	-
149	return false;	-
150	}	-
151	tmpfs_dentry_initialize(d);	-
152	d->index = tmpfs_next_index++;	-
153	root->child->sibling = d;	-
154	d->parent = root;	-
155	d->type = TMPFS_DIRECTORY;	-
156	d->name = "dir2";	-
157	hash_table_insert(&dentries, &d->index, &d->dh_link);	-
158		-
159	d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	-
160	if (!d) {	-
161	free(root->child->sibling);	-
162	free(root->child);	-
163	free(root);	-
164	root = NULL;	-
165	return false;	-
166	}	-
167	tmpfs_dentry_initialize(d);	-
168	d->index = tmpfs_next_index++;	-
169	root->child->child = d;	-
170	d->parent = root->child;	-
171	d->type = TMPFS_FILE;	-
172	d->name = "file1";	-
173	d->data = "This is the contents of /dir1/file1.\n";	-
174	d->size = strlen(d->data);	-
175	hash_table_insert(&dentries, &d->index, &d->dh_link);	-
176		-
177	d = (tmpfs_dentry_t *) malloc(sizeof(tmpfs_dentry_t));	-
178	if (!d) {	-
179	free(root->child->sibling);	-
180	free(root->child->child);	-
181	free(root->child);	-
182	free(root);	-
183	root = NULL;	-
184	return false;	-
185	}	-
186	tmpfs_dentry_initialize(d);	-
187	d->index = tmpfs_next_index++;	-
188	root->child->sibling->child = d;	-
189	d->parent = root->child->sibling;	-
190	d->type = TMPFS_FILE;	-
191	d->name = "file2";	-
192	d->data = "This is the contents of /dir2/file2.\n";	-
193	d->size = strlen(d->data);	-
194	hash_table_insert(&dentries, &d->index, &d->dh_link);	-
195		-
196	return true;	125	return true;
197	}	126	}
198		127
199	/** Compare one component of path to a directory entry.	128	/** Compare one component of path to a directory entry.
200	*	129	*
201	* @param dentry Directory entry to compare the path component with.	130	* @param dentry Directory entry to compare the path component with.
202	* @param component Array of characters holding component name.	131	* @param component Array of characters holding component name.
203	*	132	*
204	* @return True on match, false otherwise.	133	* @return True on match, false otherwise.
205	*/	134	*/
206	static bool match_component(tmpfs_dentry_t dentry, const char component)	135	static bool match_component(tmpfs_dentry_t dentry, const char component)
207	{	136	{
208	return !strcmp(dentry->name, component);	137	return !strcmp(dentry->name, component);
209	}	138	}
210		139
211	static unsigned long create_node(tmpfs_dentry_t *dentry,	140	static unsigned long create_node(tmpfs_dentry_t *dentry,
212	const char *component, int lflag)	141	const char *component, int lflag)
213	{	142	{
214	assert(dentry->type == TMPFS_DIRECTORY);	143	assert(dentry->type == TMPFS_DIRECTORY);
215	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));	144	assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
216		145
217	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));	146	tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
218	if (!node)	147	if (!node)
219	return 0;	148	return 0;
220	size_t len = strlen(component);	149	size_t len = strlen(component);
221	char *name = malloc(len + 1);	150	char *name = malloc(len + 1);
222	if (!name) {	151	if (!name) {
223	free(node);	152	free(node);
224	return 0;	153	return 0;
225	}	154	}
226	strcpy(name, component);	155	strcpy(name, component);
227		156
228	tmpfs_dentry_initialize(node);	157	tmpfs_dentry_initialize(node);
229	node->index = tmpfs_next_index++;	158	node->index = tmpfs_next_index++;
230	node->name = name;	159	node->name = name;
231	node->parent = dentry;	160	node->parent = dentry;
232	if (lflag & L_DIRECTORY)	161	if (lflag & L_DIRECTORY)
233	node->type = TMPFS_DIRECTORY;	162	node->type = TMPFS_DIRECTORY;
234	else	163	else
235	node->type = TMPFS_FILE;	164	node->type = TMPFS_FILE;
236		165
237	/* Insert the new node into the namespace. */	166	/* Insert the new node into the namespace. */
238	if (dentry->child) {	167	if (dentry->child) {
239	tmpfs_dentry_t *tmp = dentry->child;	168	tmpfs_dentry_t *tmp = dentry->child;
240	while (tmp->sibling)	169	while (tmp->sibling)
241	tmp = tmp->sibling;	170	tmp = tmp->sibling;
242	tmp->sibling = node;	171	tmp->sibling = node;
243	} else {	172	} else {
244	dentry->child = node;	173	dentry->child = node;
245	}	174	}
246		175
247	/* Insert the new node into the dentry hash table. */	176	/* Insert the new node into the dentry hash table. */
248	hash_table_insert(&dentries, &node->index, &node->dh_link);	177	hash_table_insert(&dentries, &node->index, &node->dh_link);
249	return node->index;	178	return node->index;
250	}	179	}
251		180
252	static int destroy_component(tmpfs_dentry_t *dentry)	181	static int destroy_component(tmpfs_dentry_t *dentry)
253	{	182	{
254	return EPERM;	183	return EPERM;
255	}	184	}
256		185
257	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)	186	void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
258	{	187	{
259	unsigned next = IPC_GET_ARG1(*request);	188	unsigned next = IPC_GET_ARG1(*request);
260	unsigned last = IPC_GET_ARG2(*request);	189	unsigned last = IPC_GET_ARG2(*request);
261	int dev_handle = IPC_GET_ARG3(*request);	190	int dev_handle = IPC_GET_ARG3(*request);
262	int lflag = IPC_GET_ARG4(*request);	191	int lflag = IPC_GET_ARG4(*request);
263		192
264	if (last < next)	193	if (last < next)
265	last += PLB_SIZE;	194	last += PLB_SIZE;
266		195
267	/*	196	/*
268	* Initialize TMPFS.	197	* Initialize TMPFS.
269	*/	198	*/
270	if (!root && !tmpfs_init()) {	199	if (!root && !tmpfs_init()) {
271	ipc_answer_0(rid, ENOMEM);	200	ipc_answer_0(rid, ENOMEM);
272	return;	201	return;
273	}	202	}
274		203
275	tmpfs_dentry_t *dtmp = root->child;	204	tmpfs_dentry_t *dtmp = root->child;
276	tmpfs_dentry_t *dcur = root;	205	tmpfs_dentry_t *dcur = root;
277		206
278	if (PLB_GET_CHAR(next) == '/')	207	if (PLB_GET_CHAR(next) == '/')
279	next++; /* eat slash */	208	next++; /* eat slash */
280		209
281	char component[NAME_MAX + 1];	210	char component[NAME_MAX + 1];
282	int len = 0;	211	int len = 0;
283	while (dtmp && next <= last) {	212	while (dtmp && next <= last) {
284		213
285	/* collect the component */	214	/* collect the component */
286	if (PLB_GET_CHAR(next) != '/') {	215	if (PLB_GET_CHAR(next) != '/') {
287	if (len + 1 == NAME_MAX) {	216	if (len + 1 == NAME_MAX) {
288	/* comopnent length overflow */	217	/* comopnent length overflow */
289	ipc_answer_0(rid, ENAMETOOLONG);	218	ipc_answer_0(rid, ENAMETOOLONG);
290	return;	219	return;
291	}	220	}
292	component[len++] = PLB_GET_CHAR(next);	221	component[len++] = PLB_GET_CHAR(next);
293	next++; /* process next character */	222	next++; /* process next character */
294	if (next <= last)	223	if (next <= last)
295	continue;	224	continue;
296	}	225	}
297		226
298	assert(len);	227	assert(len);
299	component[len] = '\0';	228	component[len] = '\0';
300	next++; /* eat slash */	229	next++; /* eat slash */
301	len = 0;	230	len = 0;
302		231
303	/* match the component */	232	/* match the component */
304	while (dtmp && !match_component(dtmp, component))	233	while (dtmp && !match_component(dtmp, component))
305	dtmp = dtmp->sibling;	234	dtmp = dtmp->sibling;
306		235
307	/* handle miss: match amongst siblings */	236	/* handle miss: match amongst siblings */
308	if (!dtmp) {	237	if (!dtmp) {
309	if ((next > last) && (lflag & L_CREATE)) {	238	if ((next > last) && (lflag & L_CREATE)) {
310	/* no components left and L_CREATE specified */	239	/* no components left and L_CREATE specified */
311	if (dcur->type != TMPFS_DIRECTORY) {	240	if (dcur->type != TMPFS_DIRECTORY) {
312	ipc_answer_0(rid, ENOTDIR);	241	ipc_answer_0(rid, ENOTDIR);
313	return;	242	return;
314	}	243	}
315	unsigned long index = create_node(dcur,	244	unsigned long index = create_node(dcur,
316	component, lflag);	245	component, lflag);
317	if (index > 0) {	246	if (index > 0) {
318	ipc_answer_4(rid, EOK,	247	ipc_answer_4(rid, EOK,
319	tmpfs_reg.fs_handle, dev_handle,	248	tmpfs_reg.fs_handle, dev_handle,
320	index, 0);	249	index, 0);
321	} else {	250	} else {
322	ipc_answer_0(rid, ENOSPC);	251	ipc_answer_0(rid, ENOSPC);
323	}	252	}
324	return;	253	return;
325	}	254	}
326	ipc_answer_0(rid, ENOENT);	255	ipc_answer_0(rid, ENOENT);
327	return;	256	return;
328	}	257	}
329		258
330	/* descent one level */	259	/* descent one level */
331	dcur = dtmp;	260	dcur = dtmp;
332	dtmp = dtmp->child;	261	dtmp = dtmp->child;
333	}	262	}
334		263
335	/* handle miss: excessive components */	264	/* handle miss: excessive components */
336	if (!dtmp && next <= last) {	265	if (!dtmp && next <= last) {
337	if (lflag & L_CREATE) {	266	if (lflag & L_CREATE) {
338	if (dcur->type != TMPFS_DIRECTORY) {	267	if (dcur->type != TMPFS_DIRECTORY) {
339	ipc_answer_0(rid, ENOTDIR);	268	ipc_answer_0(rid, ENOTDIR);
340	return;	269	return;
341	}	270	}
342		271
343	/* collect next component */	272	/* collect next component */
344	while (next <= last) {	273	while (next <= last) {
345	if (PLB_GET_CHAR(next) == '/') {	274	if (PLB_GET_CHAR(next) == '/') {
346	/* more than one component */	275	/* more than one component */
347	ipc_answer_0(rid, ENOENT);	276	ipc_answer_0(rid, ENOENT);
348	return;	277	return;
349	}	278	}
350	if (len + 1 == NAME_MAX) {	279	if (len + 1 == NAME_MAX) {
351	/* component length overflow */	280	/* component length overflow */
352	ipc_answer_0(rid, ENAMETOOLONG);	281	ipc_answer_0(rid, ENAMETOOLONG);
353	return;	282	return;
354	}	283	}
355	component[len++] = PLB_GET_CHAR(next);	284	component[len++] = PLB_GET_CHAR(next);
356	next++; /* process next character */	285	next++; /* process next character */
357	}	286	}
358	assert(len);	287	assert(len);
359	component[len] = '\0';	288	component[len] = '\0';
360	len = 0;	289	len = 0;
361		290
362	unsigned long index;	291	unsigned long index;
363	index = create_node(dcur, component, lflag);	292	index = create_node(dcur, component, lflag);
364	if (index) {	293	if (index) {
365	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle,	294	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle,
366	dev_handle, index, 0);	295	dev_handle, index, 0);
367	} else {	296	} else {
368	ipc_answer_0(rid, ENOSPC);	297	ipc_answer_0(rid, ENOSPC);
369	}	298	}
370	return;	299	return;
371	}	300	}
372	ipc_answer_0(rid, ENOENT);	301	ipc_answer_0(rid, ENOENT);
373	return;	302	return;
374	}	303	}
375		304
376	/* handle hit */	305	/* handle hit */
377	if (lflag & L_DESTROY) {	306	if (lflag & L_DESTROY) {
378	int res = destroy_component(dcur);	307	int res = destroy_component(dcur);
379	ipc_answer_0(rid, res);	308	ipc_answer_0(rid, res);
380	return;	309	return;
381	}	310	}
382	if ((lflag & (L_CREATE \| L_EXCLUSIVE)) == (L_CREATE \| L_EXCLUSIVE)) {	311	if ((lflag & (L_CREATE \| L_EXCLUSIVE)) == (L_CREATE \| L_EXCLUSIVE)) {
383	ipc_answer_0(rid, EEXIST);	312	ipc_answer_0(rid, EEXIST);
384	return;	313	return;
385	}	314	}
386	if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {	315	if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {
387	ipc_answer_0(rid, EISDIR);	316	ipc_answer_0(rid, EISDIR);
388	return;	317	return;
389	}	318	}
390	if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {	319	if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {
391	ipc_answer_0(rid, ENOTDIR);	320	ipc_answer_0(rid, ENOTDIR);
392	return;	321	return;
393	}	322	}
394		323
395	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,	324	ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
396	dcur->size);	325	dcur->size);
397	}	326	}
398		327
399	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)	328	void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
400	{	329	{
401	int dev_handle = IPC_GET_ARG1(*request);	330	int dev_handle = IPC_GET_ARG1(*request);
402	unsigned long index = IPC_GET_ARG2(*request);	331	unsigned long index = IPC_GET_ARG2(*request);
403	off_t pos = IPC_GET_ARG3(*request);	332	off_t pos = IPC_GET_ARG3(*request);
404		333
405	/*	334	/*
406	* Lookup the respective dentry.	335	* Lookup the respective dentry.
407	*/	336	*/
408	link_t *hlp;	337	link_t *hlp;
409	hlp = hash_table_find(&dentries, &index);	338	hlp = hash_table_find(&dentries, &index);
410	if (!hlp) {	339	if (!hlp) {
411	ipc_answer_0(rid, ENOENT);	340	ipc_answer_0(rid, ENOENT);
412	return;	341	return;
413	}	342	}
414	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	343	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
415	dh_link);	344	dh_link);
416		345
417	/*	346	/*
418	* Receive the read request.	347	* Receive the read request.
419	*/	348	*/
420	ipc_callid_t callid;	349	ipc_callid_t callid;
421	size_t len;	350	size_t len;
422	if (!ipc_data_read_receive(&callid, &len)) {	351	if (!ipc_data_read_receive(&callid, &len)) {
423	ipc_answer_0(callid, EINVAL);	352	ipc_answer_0(callid, EINVAL);
424	ipc_answer_0(rid, EINVAL);	353	ipc_answer_0(rid, EINVAL);
425	return;	354	return;
426	}	355	}
427		356
428	size_t bytes;	357	size_t bytes;
429	if (dentry->type == TMPFS_FILE) {	358	if (dentry->type == TMPFS_FILE) {
430	bytes = max(0, min(dentry->size - pos, len));	359	bytes = max(0, min(dentry->size - pos, len));
431	(void) ipc_data_read_finalize(callid, dentry->data + pos,	360	(void) ipc_data_read_finalize(callid, dentry->data + pos,
432	bytes);	361	bytes);
433	} else {	362	} else {
434	int i;	363	int i;
435	tmpfs_dentry_t *cur = dentry->child;	364	tmpfs_dentry_t *cur = dentry->child;
436		365
437	assert(dentry->type == TMPFS_DIRECTORY);	366	assert(dentry->type == TMPFS_DIRECTORY);
438		367
439	/*	368	/*
440	* Yes, we really use O(n) algorithm here.	369	* Yes, we really use O(n) algorithm here.
441	* If it bothers someone, it could be fixed by introducing a	370	* If it bothers someone, it could be fixed by introducing a
442	* hash table.	371	* hash table.
443	*/	372	*/
444	for (i = 0, cur = dentry->child; i < pos && cur; i++,	373	for (i = 0, cur = dentry->child; i < pos && cur; i++,
445	cur = cur->sibling)	374	cur = cur->sibling)
446	;	375	;
447		376
448	if (!cur) {	377	if (!cur) {
449	ipc_answer_0(callid, ENOENT);	378	ipc_answer_0(callid, ENOENT);
450	ipc_answer_1(rid, ENOENT, 0);	379	ipc_answer_1(rid, ENOENT, 0);
451	return;	380	return;
452	}	381	}
453		382
454	(void) ipc_data_read_finalize(callid, cur->name,	383	(void) ipc_data_read_finalize(callid, cur->name,
455	strlen(cur->name) + 1);	384	strlen(cur->name) + 1);
456	bytes = 1;	385	bytes = 1;
457	}	386	}
458		387
459	/*	388	/*
460	* Answer the VFS_READ call.	389	* Answer the VFS_READ call.
461	*/	390	*/
462	ipc_answer_1(rid, EOK, bytes);	391	ipc_answer_1(rid, EOK, bytes);
463	}	392	}
464		393
465	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)	394	void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
466	{	395	{
467	int dev_handle = IPC_GET_ARG1(*request);	396	int dev_handle = IPC_GET_ARG1(*request);
468	unsigned long index = IPC_GET_ARG2(*request);	397	unsigned long index = IPC_GET_ARG2(*request);
469	off_t pos = IPC_GET_ARG3(*request);	398	off_t pos = IPC_GET_ARG3(*request);
470		399
471	/*	400	/*
472	* Lookup the respective dentry.	401	* Lookup the respective dentry.
473	*/	402	*/
474	link_t *hlp;	403	link_t *hlp;
475	hlp = hash_table_find(&dentries, &index);	404	hlp = hash_table_find(&dentries, &index);
476	if (!hlp) {	405	if (!hlp) {
477	ipc_answer_0(rid, ENOENT);	406	ipc_answer_0(rid, ENOENT);
478	return;	407	return;
479	}	408	}
480	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,	409	tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
481	dh_link);	410	dh_link);
482		411
483	/*	412	/*
484	* Receive the write request.	413	* Receive the write request.
485	*/	414	*/
486	ipc_callid_t callid;	415	ipc_callid_t callid;
487	size_t len;	416	size_t len;
488	if (!ipc_data_write_receive(&callid, &len)) {	417	if (!ipc_data_write_receive(&callid, &len)) {
489	ipc_answer_0(callid, EINVAL);	418	ipc_answer_0(callid, EINVAL);
490	ipc_answer_0(rid, EINVAL);	419	ipc_answer_0(rid, EINVAL);
491	return;	420	return;
492	}	421	}
493		422
494	/*	423	/*
495	* Check whether the file needs to grow.	424	* Check whether the file needs to grow.
496	*/	425	*/
497	if (pos + len <= dentry->size) {	426	if (pos + len <= dentry->size) {
498	/* The file size is not changing. */	427	/* The file size is not changing. */
499	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);	428	(void) ipc_data_write_finalize(callid, dentry->data + pos, len);
500	ipc_answer_2(rid, EOK, len, dentry->size);	429	ipc_answer_2(rid, EOK, len, dentry->size);

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(root)/branches/dynload/uspace/srv/fs/tmpfs/tmpfs_ops.c @ 4751 – Rev 2710 → 2711