WebSVN – HelenOS – Diff – /branches/dynload/uspace/srv/vfs/vfs_register.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    vfs_register.c
 * @brief
 */
 
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <async.h>
#include <fibril.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <bool.h>
#include <futex.h>
#include <libadt/list.h>
#include <as.h>
#include <assert.h>
#include <atomic.h>
#include "vfs.h"
 
atomic_t fs_head_futex = FUTEX_INITIALIZER;
link_t fs_head;
 
atomic_t fs_handle_next = {
    .count = 1
};
 
/** Verify the VFS info structure.
 *
 * @param info      Info structure to be verified.
 *
 * @return      Non-zero if the info structure is sane, zero otherwise.
 */
static bool vfs_info_sane(vfs_info_t *info)
{
    int i;
 
    /*
     * Check if the name is non-empty and is composed solely of ASCII
     * characters [a-z]+[a-z0-9_-]*.
     */
    if (!islower(info->name[0])) {
        dprintf("The name doesn't start with a lowercase character.\n");
        return false;
    }
    for (i = 1; i < FS_NAME_MAXLEN; i++) {
        if (!(islower(info->name[i]) || isdigit(info->name[i])) &&
            (info->name[i] != '-') && (info->name[i] != '_')) {
            if (info->name[i] == '\0') {
                break;
            } else {
                dprintf("The name contains illegal "
                    "characters.\n");
                return false;
            }
        }
    }
    /*
     * This check is not redundant. It ensures that the name is
     * NULL-terminated, even if FS_NAME_MAXLEN characters are used.
     */
    if (info->name[i] != '\0') {
        dprintf("The name is not properly NULL-terminated.\n");
        return false;
    }
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    return true;
}
 
/** VFS_REGISTER protocol function.
 *
 * @param rid       Hash of the call with the request.
 * @param request   Call structure with the request.
 */
void vfs_register(ipc_callid_t rid, ipc_call_t *request)
{
    ipc_callid_t callid;
    ipc_call_t call;
    int rc;
    size_t size;
 
    dprintf("Processing VFS_REGISTER request received from %p.\n",
        request->in_phone_hash);
 
    /*
     * The first call has to be IPC_M_DATA_SEND in which we receive the
     * VFS info structure from the client FS.
     */
    if (!ipc_data_write_receive(&callid, &size)) {
        /*
         * The client doesn't obey the same protocol as we do.
         */
        dprintf("Receiving of VFS info failed.\n");
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
   
    dprintf("VFS info received, size = %d\n", size);
   
    /*
     * We know the size of the VFS info structure. See if the client
     * understands this easy concept too.
     */
    if (size != sizeof(vfs_info_t)) {
        /*
         * The client is sending us something, which cannot be
         * the info structure.
         */
        dprintf("Received VFS info has bad size.\n");
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    /*
     * Allocate and initialize a buffer for the fs_info structure.
     */
    fs_info_t *fs_info;
    fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
    if (!fs_info) {
        dprintf("Could not allocate memory for FS info.\n");
        ipc_answer_0(callid, ENOMEM);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    link_initialize(&fs_info->fs_link);
    futex_initialize(&fs_info->phone_futex, 1);
       
    rc = ipc_data_write_finalize(callid, &fs_info->vfs_info, size);
    if (rc != EOK) {
        dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
            rc);
        free(fs_info);
        ipc_answer_0(callid, rc);
        ipc_answer_0(rid, rc);
        return;
    }
 
    dprintf("VFS info delivered.\n");
       
    if (!vfs_info_sane(&fs_info->vfs_info)) {
        free(fs_info);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
       
    futex_down(&fs_head_futex);
    fibril_inc_sercount();
 
    /*
     * Check for duplicit registrations.
     */
    if (fs_name_to_handle(fs_info->vfs_info.name, false)) {
        /*
         * We already register a fs like this.
         */
        dprintf("FS is already registered.\n");
        fibril_dec_sercount();
        futex_up(&fs_head_futex);
        free(fs_info);
        ipc_answer_0(callid, EEXISTS);
        ipc_answer_0(rid, EEXISTS);
        return;
    }
 
    /*
     * Add fs_info to the list of registered FS's.
     */
    dprintf("Inserting FS into the list of registered file systems.\n");
    list_append(&fs_info->fs_link, &fs_head);
   
    /*
     * Now we want the client to send us the IPC_M_CONNECT_TO_ME call so
     * that a callback connection is created and we have a phone through
     * which to forward VFS requests to it.
     */
    callid = async_get_call(&call);
    if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
        dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
        list_remove(&fs_info->fs_link);
        fibril_dec_sercount();
        futex_up(&fs_head_futex);
        free(fs_info);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    fs_info->phone = IPC_GET_ARG5(call);
    ipc_answer_0(callid, EOK);
 
    dprintf("Callback connection to FS created.\n");
 
    /*
     * The client will want us to send him the address space area with PLB.
     */
 
    if (!ipc_share_in_receive(&callid, &size)) {
        dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
        list_remove(&fs_info->fs_link);
        fibril_dec_sercount();
        futex_up(&fs_head_futex);
        ipc_hangup(fs_info->phone);
        free(fs_info);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
   
    /*
     * We can only send the client address space area PLB_SIZE bytes long.
     */
    if (size != PLB_SIZE) {
        dprintf("Client suggests wrong size of PFB, size = %d\n", size);
        list_remove(&fs_info->fs_link);
        fibril_dec_sercount();
        futex_up(&fs_head_futex);
        ipc_hangup(fs_info->phone);
        free(fs_info);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    /*
     * Commit to read-only sharing the PLB with the client.
     */
    (void) ipc_share_in_finalize(callid, plb,
        AS_AREA_READ | AS_AREA_CACHEABLE);
 
    dprintf("Sharing PLB.\n");
 
    /*
     * That was it. The FS has been registered.
     * In reply to the VFS_REGISTER request, we assign the client file
     * system a global file system handle.
     */
    fs_info->fs_handle = (fs_handle_t) atomic_postinc(&fs_handle_next);
    ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);
   
    fibril_dec_sercount();
    futex_up(&fs_head_futex);
   
    dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
        FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);
}
 
/** For a given file system handle, implement policy for allocating a phone.
 *
 * @param handle    File system handle.
 *
 * @return      Phone over which a multi-call request can be safely
 *          sent. Return 0 if no phone was found.
 */
int vfs_grab_phone(fs_handle_t handle)
{
    /*
     * For now, we don't try to be very clever and very fast.
     * We simply lookup the phone in the fs_head list. We currently don't
     * open any additional phones (even though that itself would be pretty
     * straightforward; housekeeping multiple open phones to a FS task would
     * be more demanding). Instead, we simply take the respective
     * phone_futex and keep it until vfs_release_phone().
     */
    futex_down(&fs_head_futex);
    link_t *cur;
    fs_info_t *fs;
    for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
        fs = list_get_instance(cur, fs_info_t, fs_link);
        if (fs->fs_handle == handle) {
            futex_up(&fs_head_futex);
            /*
             * For now, take the futex unconditionally.
             * Oh yeah, serialization rocks.
             * It will be up'ed in vfs_release_phone().
             */
            futex_down(&fs->phone_futex);
            /*
             * Avoid deadlock with other fibrils in the same thread
             * by disabling fibril preemption.
             */
            fibril_inc_sercount();
            return fs->phone;
        }
    }
    futex_up(&fs_head_futex);
    return 0;
}
 
/** Tell VFS that the phone is in use for any request.
 *
 * @param phone     Phone to FS task.
 */
void vfs_release_phone(int phone)
{
    bool found = false;
 
    /*
     * Undo the fibril_inc_sercount() done in vfs_grab_phone().
     */
    fibril_dec_sercount();
   
    futex_down(&fs_head_futex);
    link_t *cur;
    for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
        fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
        if (fs->phone == phone) {
            found = true;
            futex_up(&fs_head_futex);
            futex_up(&fs->phone_futex);
            return;
        }
    }
    futex_up(&fs_head_futex);
 
    /*
     * Not good to get here.
     */
    assert(found == true);
}
 
/** Convert file system name to its handle.
 *
 * @param name      File system name.
 * @param lock      If true, the function will down and up the
 *          fs_head_futex.
 *
 * @return      File system handle or zero if file system not found.
 */
fs_handle_t fs_name_to_handle(char *name, bool lock)
{
    int handle = 0;
   
    if (lock)
        futex_down(&fs_head_futex);
    link_t *cur;
    for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
        fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
        if (strncmp(fs->vfs_info.name, name,
            sizeof(fs->vfs_info.name)) == 0) {
            handle = fs->fs_handle;
            break;
        }
    }
    if (lock)
        futex_up(&fs_head_futex);
    return handle;
}
 
/**
 * @}
 */
 

Rev 2927	Rev 4341
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 vfs_register.c	34	* @file vfs_register.c
35	* @brief	35	* @brief
36	*/	36	*/
37		37
38	#include <ipc/ipc.h>	38	#include <ipc/ipc.h>
39	#include <ipc/services.h>	39	#include <ipc/services.h>
40	#include <async.h>	40	#include <async.h>
41	#include <fibril.h>	41	#include <fibril.h>
42	#include <errno.h>	42	#include <errno.h>
43	#include <stdio.h>	43	#include <stdio.h>
44	#include <stdlib.h>	44	#include <stdlib.h>
45	#include <string.h>	45	#include <string.h>
46	#include <ctype.h>	46	#include <ctype.h>
47	#include <bool.h>	47	#include <bool.h>
48	#include <futex.h>	48	#include <futex.h>
49	#include <libadt/list.h>	49	#include <libadt/list.h>
50	#include <as.h>	50	#include <as.h>
51	#include <assert.h>	51	#include <assert.h>
52	#include <atomic.h>	52	#include <atomic.h>
53	#include "vfs.h"	53	#include "vfs.h"
54		54
55	atomic_t fs_head_futex = FUTEX_INITIALIZER;	55	atomic_t fs_head_futex = FUTEX_INITIALIZER;
56	link_t fs_head;	56	link_t fs_head;
57		57
58	atomic_t fs_handle_next = {	58	atomic_t fs_handle_next = {
59	.count = 1	59	.count = 1
60	};	60	};
61		61
62	/** Verify the VFS info structure.	62	/** Verify the VFS info structure.
63	*	63	*
64	* @param info Info structure to be verified.	64	* @param info Info structure to be verified.
65	*	65	*
66	* @return Non-zero if the info structure is sane, zero otherwise.	66	* @return Non-zero if the info structure is sane, zero otherwise.
67	*/	67	*/
68	static bool vfs_info_sane(vfs_info_t *info)	68	static bool vfs_info_sane(vfs_info_t *info)
69	{	69	{
70	int i;	70	int i;
71		71
72	/*	72	/*
73	* Check if the name is non-empty and is composed solely of ASCII	73	* Check if the name is non-empty and is composed solely of ASCII
74	* characters [a-z]+[a-z0-9_-]*.	74	* characters [a-z]+[a-z0-9_-]*.
75	*/	75	*/
76	if (!islower(info->name[0])) {	76	if (!islower(info->name[0])) {
77	dprintf("The name doesn't start with a lowercase character.\n");	77	dprintf("The name doesn't start with a lowercase character.\n");
78	return false;	78	return false;
79	}	79	}
80	for (i = 1; i < FS_NAME_MAXLEN; i++) {	80	for (i = 1; i < FS_NAME_MAXLEN; i++) {
81	if (!(islower(info->name[i]) \|\| isdigit(info->name[i])) &&	81	if (!(islower(info->name[i]) \|\| isdigit(info->name[i])) &&
82	(info->name[i] != '-') && (info->name[i] != '_')) {	82	(info->name[i] != '-') && (info->name[i] != '_')) {
83	if (info->name[i] == '\0') {	83	if (info->name[i] == '\0') {
84	break;	84	break;
85	} else {	85	} else {
86	dprintf("The name contains illegal "	86	dprintf("The name contains illegal "
87	"characters.\n");	87	"characters.\n");
88	return false;	88	return false;
89	}	89	}
90	}	90	}
91	}	91	}
92	/*	92	/*
93	* This check is not redundant. It ensures that the name is	93	* This check is not redundant. It ensures that the name is
94	* NULL-terminated, even if FS_NAME_MAXLEN characters are used.	94	* NULL-terminated, even if FS_NAME_MAXLEN characters are used.
95	*/	95	*/
96	if (info->name[i] != '\0') {	96	if (info->name[i] != '\0') {
97	dprintf("The name is not properly NULL-terminated.\n");	97	dprintf("The name is not properly NULL-terminated.\n");
98	return false;	98	return false;
99	}	99	}
100		100
101		-
102	/*	-
103	* Check if the FS implements mandatory VFS operations.	-
104	*/	-
105	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] != VFS_OP_DEFINED) {	-
106	dprintf("Operation VFS_LOOKUP not defined by the client.\n");	-
107	return false;	-
108	}	-
109	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED) {	-
110	dprintf("Operation VFS_READ not defined by the client.\n");	-
111	return false;	-
112	}	-
113		-
114	/*	-
115	* Check if each operation is either not defined, defined or default.	-
116	*/	-
117	for (i = VFS_FIRST; i < VFS_LAST_CLNT; i++) {	-
118	if ((info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_NULL) &&	-
119	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFAULT) &&	-
120	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFINED)) {	-
121	dprintf("Operation info not understood.\n");	-
122	return false;	-
123	}	-
124	}	-
125	return true;	101	return true;
126	}	102	}
127		103
128	/** VFS_REGISTER protocol function.	104	/** VFS_REGISTER protocol function.
129	*	105	*
130	* @param rid Hash of the call with the request.	106	* @param rid Hash of the call with the request.
131	* @param request Call structure with the request.	107	* @param request Call structure with the request.
132	*/	108	*/
133	void vfs_register(ipc_callid_t rid, ipc_call_t *request)	109	void vfs_register(ipc_callid_t rid, ipc_call_t *request)
134	{	110	{
135	ipc_callid_t callid;	111	ipc_callid_t callid;
136	ipc_call_t call;	112	ipc_call_t call;
137	int rc;	113	int rc;
138	size_t size;	114	size_t size;
139		115
140	dprintf("Processing VFS_REGISTER request received from %p.\n",	116	dprintf("Processing VFS_REGISTER request received from %p.\n",
141	request->in_phone_hash);	117	request->in_phone_hash);
142		118
143	/*	119	/*
144	* The first call has to be IPC_M_DATA_SEND in which we receive the	120	* The first call has to be IPC_M_DATA_SEND in which we receive the
145	* VFS info structure from the client FS.	121	* VFS info structure from the client FS.
146	*/	122	*/
147	if (!ipc_data_write_receive(&callid, &size)) {	123	if (!ipc_data_write_receive(&callid, &size)) {
148	/*	124	/*
149	* The client doesn't obey the same protocol as we do.	125	* The client doesn't obey the same protocol as we do.
150	*/	126	*/
151	dprintf("Receiving of VFS info failed.\n");	127	dprintf("Receiving of VFS info failed.\n");
152	ipc_answer_0(callid, EINVAL);	128	ipc_answer_0(callid, EINVAL);
153	ipc_answer_0(rid, EINVAL);	129	ipc_answer_0(rid, EINVAL);
154	return;	130	return;
155	}	131	}
156		132
157	dprintf("VFS info received, size = %d\n", size);	133	dprintf("VFS info received, size = %d\n", size);
158		134
159	/*	135	/*
160	* We know the size of the VFS info structure. See if the client	136	* We know the size of the VFS info structure. See if the client
161	* understands this easy concept too.	137	* understands this easy concept too.
162	*/	138	*/
163	if (size != sizeof(vfs_info_t)) {	139	if (size != sizeof(vfs_info_t)) {
164	/*	140	/*
165	* The client is sending us something, which cannot be	141	* The client is sending us something, which cannot be
166	* the info structure.	142	* the info structure.
167	*/	143	*/
168	dprintf("Received VFS info has bad size.\n");	144	dprintf("Received VFS info has bad size.\n");
169	ipc_answer_0(callid, EINVAL);	145	ipc_answer_0(callid, EINVAL);
170	ipc_answer_0(rid, EINVAL);	146	ipc_answer_0(rid, EINVAL);
171	return;	147	return;
172	}	148	}
173		149
174	/*	150	/*
175	* Allocate and initialize a buffer for the fs_info structure.	151	* Allocate and initialize a buffer for the fs_info structure.
176	*/	152	*/
177	fs_info_t *fs_info;	153	fs_info_t *fs_info;
178	fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));	154	fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
179	if (!fs_info) {	155	if (!fs_info) {
180	dprintf("Could not allocate memory for FS info.\n");	156	dprintf("Could not allocate memory for FS info.\n");
181	ipc_answer_0(callid, ENOMEM);	157	ipc_answer_0(callid, ENOMEM);
182	ipc_answer_0(rid, ENOMEM);	158	ipc_answer_0(rid, ENOMEM);
183	return;	159	return;
184	}	160	}
185	link_initialize(&fs_info->fs_link);	161	link_initialize(&fs_info->fs_link);
186	futex_initialize(&fs_info->phone_futex, 1);	162	futex_initialize(&fs_info->phone_futex, 1);
187		163
188	rc = ipc_data_write_finalize(callid, &fs_info->vfs_info, size);	164	rc = ipc_data_write_finalize(callid, &fs_info->vfs_info, size);
189	if (rc != EOK) {	165	if (rc != EOK) {
190	dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",	166	dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
191	rc);	167	rc);
192	free(fs_info);	168	free(fs_info);
193	ipc_answer_0(callid, rc);	169	ipc_answer_0(callid, rc);
194	ipc_answer_0(rid, rc);	170	ipc_answer_0(rid, rc);
195	return;	171	return;
196	}	172	}
197		173
198	dprintf("VFS info delivered.\n");	174	dprintf("VFS info delivered.\n");
199		175
200	if (!vfs_info_sane(&fs_info->vfs_info)) {	176	if (!vfs_info_sane(&fs_info->vfs_info)) {
201	free(fs_info);	177	free(fs_info);
202	ipc_answer_0(callid, EINVAL);	178	ipc_answer_0(callid, EINVAL);
203	ipc_answer_0(rid, EINVAL);	179	ipc_answer_0(rid, EINVAL);
204	return;	180	return;
205	}	181	}
206		182
207	futex_down(&fs_head_futex);	183	futex_down(&fs_head_futex);
208	fibril_inc_sercount();	184	fibril_inc_sercount();
209		185
210	/*	186	/*
211	* Check for duplicit registrations.	187	* Check for duplicit registrations.
212	*/	188	*/
213	if (fs_name_to_handle(fs_info->vfs_info.name, false)) {	189	if (fs_name_to_handle(fs_info->vfs_info.name, false)) {
214	/*	190	/*
215	* We already register a fs like this.	191	* We already register a fs like this.
216	*/	192	*/
217	dprintf("FS is already registered.\n");	193	dprintf("FS is already registered.\n");
218	fibril_dec_sercount();	194	fibril_dec_sercount();
219	futex_up(&fs_head_futex);	195	futex_up(&fs_head_futex);
220	free(fs_info);	196	free(fs_info);
221	ipc_answer_0(callid, EEXISTS);	197	ipc_answer_0(callid, EEXISTS);
222	ipc_answer_0(rid, EEXISTS);	198	ipc_answer_0(rid, EEXISTS);
223	return;	199	return;
224	}	200	}
225		201
226	/*	202	/*
227	* Add fs_info to the list of registered FS's.	203	* Add fs_info to the list of registered FS's.
228	*/	204	*/
229	dprintf("Inserting FS into the list of registered file systems.\n");	205	dprintf("Inserting FS into the list of registered file systems.\n");
230	list_append(&fs_info->fs_link, &fs_head);	206	list_append(&fs_info->fs_link, &fs_head);
231		207
232	/*	208	/*
233	* Now we want the client to send us the IPC_M_CONNECT_TO_ME call so	209	* Now we want the client to send us the IPC_M_CONNECT_TO_ME call so
234	* that a callback connection is created and we have a phone through	210	* that a callback connection is created and we have a phone through
235	* which to forward VFS requests to it.	211	* which to forward VFS requests to it.
236	*/	212	*/
237	callid = async_get_call(&call);	213	callid = async_get_call(&call);
238	if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {	214	if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
239	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));	215	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
240	list_remove(&fs_info->fs_link);	216	list_remove(&fs_info->fs_link);
241	fibril_dec_sercount();	217	fibril_dec_sercount();
242	futex_up(&fs_head_futex);	218	futex_up(&fs_head_futex);
243	free(fs_info);	219	free(fs_info);
244	ipc_answer_0(callid, EINVAL);	220	ipc_answer_0(callid, EINVAL);
245	ipc_answer_0(rid, EINVAL);	221	ipc_answer_0(rid, EINVAL);
246	return;	222	return;
247	}	223	}
248	fs_info->phone = IPC_GET_ARG5(call);	224	fs_info->phone = IPC_GET_ARG5(call);
249	ipc_answer_0(callid, EOK);	225	ipc_answer_0(callid, EOK);
250		226
251	dprintf("Callback connection to FS created.\n");	227	dprintf("Callback connection to FS created.\n");
252		228
253	/*	229	/*
254	* The client will want us to send him the address space area with PLB.	230	* The client will want us to send him the address space area with PLB.
255	*/	231	*/
256		232
257	if (!ipc_share_in_receive(&callid, &size)) {	233	if (!ipc_share_in_receive(&callid, &size)) {
258	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));	234	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
259	list_remove(&fs_info->fs_link);	235	list_remove(&fs_info->fs_link);
260	fibril_dec_sercount();	236	fibril_dec_sercount();
261	futex_up(&fs_head_futex);	237	futex_up(&fs_head_futex);
262	ipc_hangup(fs_info->phone);	238	ipc_hangup(fs_info->phone);
263	free(fs_info);	239	free(fs_info);
264	ipc_answer_0(callid, EINVAL);	240	ipc_answer_0(callid, EINVAL);
265	ipc_answer_0(rid, EINVAL);	241	ipc_answer_0(rid, EINVAL);
266	return;	242	return;
267	}	243	}
268		244
269	/*	245	/*
270	* We can only send the client address space area PLB_SIZE bytes long.	246	* We can only send the client address space area PLB_SIZE bytes long.
271	*/	247	*/
272	if (size != PLB_SIZE) {	248	if (size != PLB_SIZE) {
273	dprintf("Client suggests wrong size of PFB, size = %d\n", size);	249	dprintf("Client suggests wrong size of PFB, size = %d\n", size);
274	list_remove(&fs_info->fs_link);	250	list_remove(&fs_info->fs_link);
275	fibril_dec_sercount();	251	fibril_dec_sercount();
276	futex_up(&fs_head_futex);	252	futex_up(&fs_head_futex);
277	ipc_hangup(fs_info->phone);	253	ipc_hangup(fs_info->phone);
278	free(fs_info);	254	free(fs_info);
279	ipc_answer_0(callid, EINVAL);	255	ipc_answer_0(callid, EINVAL);
280	ipc_answer_0(rid, EINVAL);	256	ipc_answer_0(rid, EINVAL);
281	return;	257	return;
282	}	258	}
283		259
284	/*	260	/*
285	* Commit to read-only sharing the PLB with the client.	261	* Commit to read-only sharing the PLB with the client.
286	*/	262	*/
287	(void) ipc_share_in_finalize(callid, plb,	263	(void) ipc_share_in_finalize(callid, plb,
288	AS_AREA_READ \| AS_AREA_CACHEABLE);	264	AS_AREA_READ \| AS_AREA_CACHEABLE);
289		265
290	dprintf("Sharing PLB.\n");	266	dprintf("Sharing PLB.\n");
291		267
292	/*	268	/*
293	* That was it. The FS has been registered.	269	* That was it. The FS has been registered.
294	* In reply to the VFS_REGISTER request, we assign the client file	270	* In reply to the VFS_REGISTER request, we assign the client file
295	* system a global file system handle.	271	* system a global file system handle.
296	*/	272	*/
297	fs_info->fs_handle = (fs_handle_t) atomic_postinc(&fs_handle_next);	273	fs_info->fs_handle = (fs_handle_t) atomic_postinc(&fs_handle_next);
298	ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);	274	ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);
299		275
300	fibril_dec_sercount();	276	fibril_dec_sercount();
301	futex_up(&fs_head_futex);	277	futex_up(&fs_head_futex);
302		278
303	dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",	279	dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
304	FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);	280	FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);
305	}	281	}
306		282
307	/** For a given file system handle, implement policy for allocating a phone.	283	/** For a given file system handle, implement policy for allocating a phone.
308	*	284	*
309	* @param handle File system handle.	285	* @param handle File system handle.
310	*	286	*
311	* @return Phone over which a multi-call request can be safely	287	* @return Phone over which a multi-call request can be safely
312	* sent. Return 0 if no phone was found.	288	* sent. Return 0 if no phone was found.
313	*/	289	*/
314	int vfs_grab_phone(fs_handle_t handle)	290	int vfs_grab_phone(fs_handle_t handle)
315	{	291	{
316	/*	292	/*
317	* For now, we don't try to be very clever and very fast.	293	* For now, we don't try to be very clever and very fast.
318	* We simply lookup the phone in the fs_head list. We currently don't	294	* We simply lookup the phone in the fs_head list. We currently don't
319	* open any additional phones (even though that itself would be pretty	295	* open any additional phones (even though that itself would be pretty
320	* straightforward; housekeeping multiple open phones to a FS task would	296	* straightforward; housekeeping multiple open phones to a FS task would
321	* be more demanding). Instead, we simply take the respective	297	* be more demanding). Instead, we simply take the respective
322	* phone_futex and keep it until vfs_release_phone().	298	* phone_futex and keep it until vfs_release_phone().
323	*/	299	*/
324	futex_down(&fs_head_futex);	300	futex_down(&fs_head_futex);
325	link_t *cur;	301	link_t *cur;
326	fs_info_t *fs;	302	fs_info_t *fs;
327	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	303	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
328	fs = list_get_instance(cur, fs_info_t, fs_link);	304	fs = list_get_instance(cur, fs_info_t, fs_link);
329	if (fs->fs_handle == handle) {	305	if (fs->fs_handle == handle) {
330	futex_up(&fs_head_futex);	306	futex_up(&fs_head_futex);
331	/*	307	/*
332	* For now, take the futex unconditionally.	308	* For now, take the futex unconditionally.
333	* Oh yeah, serialization rocks.	309	* Oh yeah, serialization rocks.
334	* It will be up'ed in vfs_release_phone().	310	* It will be up'ed in vfs_release_phone().
335	*/	311	*/
336	futex_down(&fs->phone_futex);	312	futex_down(&fs->phone_futex);
337	/*	313	/*
338	* Avoid deadlock with other fibrils in the same thread	314	* Avoid deadlock with other fibrils in the same thread
339	* by disabling fibril preemption.	315	* by disabling fibril preemption.
340	*/	316	*/
341	fibril_inc_sercount();	317	fibril_inc_sercount();
342	return fs->phone;	318	return fs->phone;
343	}	319	}
344	}	320	}
345	futex_up(&fs_head_futex);	321	futex_up(&fs_head_futex);
346	return 0;	322	return 0;
347	}	323	}
348		324
349	/** Tell VFS that the phone is in use for any request.	325	/** Tell VFS that the phone is in use for any request.
350	*	326	*
351	* @param phone Phone to FS task.	327	* @param phone Phone to FS task.
352	*/	328	*/
353	void vfs_release_phone(int phone)	329	void vfs_release_phone(int phone)
354	{	330	{
355	bool found = false;	331	bool found = false;
356		332
357	/*	333	/*
358	* Undo the fibril_inc_sercount() done in vfs_grab_phone().	334	* Undo the fibril_inc_sercount() done in vfs_grab_phone().
359	*/	335	*/
360	fibril_dec_sercount();	336	fibril_dec_sercount();
361		337
362	futex_down(&fs_head_futex);	338	futex_down(&fs_head_futex);
363	link_t *cur;	339	link_t *cur;
364	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	340	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
365	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);	341	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
366	if (fs->phone == phone) {	342	if (fs->phone == phone) {
367	found = true;	343	found = true;
368	futex_up(&fs_head_futex);	344	futex_up(&fs_head_futex);
369	futex_up(&fs->phone_futex);	345	futex_up(&fs->phone_futex);
370	return;	346	return;
371	}	347	}
372	}	348	}
373	futex_up(&fs_head_futex);	349	futex_up(&fs_head_futex);
374		350
375	/*	351	/*
376	* Not good to get here.	352	* Not good to get here.
377	*/	353	*/
378	assert(found == true);	354	assert(found == true);
379	}	355	}
380		356
381	/** Convert file system name to its handle.	357	/** Convert file system name to its handle.
382	*	358	*
383	* @param name File system name.	359	* @param name File system name.
384	* @param lock If true, the function will down and up the	360	* @param lock If true, the function will down and up the
385	* fs_head_futex.	361	* fs_head_futex.
386	*	362	*
387	* @return File system handle or zero if file system not found.	363	* @return File system handle or zero if file system not found.
388	*/	364	*/
389	fs_handle_t fs_name_to_handle(char *name, bool lock)	365	fs_handle_t fs_name_to_handle(char *name, bool lock)
390	{	366	{
391	int handle = 0;	367	int handle = 0;
392		368
393	if (lock)	369	if (lock)
394	futex_down(&fs_head_futex);	370	futex_down(&fs_head_futex);
395	link_t *cur;	371	link_t *cur;
396	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	372	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
397	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);	373	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
398	if (strncmp(fs->vfs_info.name, name,	374	if (strncmp(fs->vfs_info.name, name,
399	sizeof(fs->vfs_info.name)) == 0) {	375	sizeof(fs->vfs_info.name)) == 0) {
400	handle = fs->fs_handle;	376	handle = fs->fs_handle;
401	break;	377	break;
402	}	378	}
403	}	379	}
404	if (lock)	380	if (lock)
405	futex_up(&fs_head_futex);	381	futex_up(&fs_head_futex);
406	return handle;	382	return handle;
407	}	383	}
408		384
409	/**	385	/**
410	* @}	386	* @}
411	*/	387	*/
412		388

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(root)/branches/dynload/uspace/srv/vfs/vfs_register.c – Rev 2927 → 4341