WebSVN – HelenOS – Diff – /trunk/uspace/srv/vfs/vfs_register.c


/*
 * Copyright (c) 2007 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   VFS_REGISTER method.
 */
 
#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 <as.h>
#include <libadt/list.h>
#include <assert.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;
            }
        }
    }
   
 
    /*
     * Check if the FS implements mandatory VFS operations.
     */
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_REGISTER not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_MOUNT not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_UNMOUNT not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_LOOKUP not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_OPEN not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_CLOSE not defined by the client.\n");
        return false;
    }
    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED) {
        dprintf("Operation VFS_READ not defined by the client.\n");
        return false;
    }
   
    /*
     * Check if each operation is either not defined, defined or default.
     */
    for (i = VFS_FIRST; i < VFS_LAST; i++) {
        if ((info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_NULL) &&
            (info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFAULT) &&
            (info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFINED)) {
            dprintf("Operation info not understood.\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_receive(&callid, NULL, &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);
       
    rc = ipc_data_deliver(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);
 
    /*
     * 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");
        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);
        futex_up(&fs_head_futex);
        free(fs_info);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
    fs_info->phone = IPC_GET_ARG3(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.
     */
    callid = async_get_call(&call);
    if (IPC_GET_METHOD(call) != IPC_M_AS_AREA_RECV) {
        dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
        list_remove(&fs_info->fs_link);
        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.
     */
    size = IPC_GET_ARG2(call);
    if (size != PLB_SIZE) {
        dprintf("Client suggests wrong size of PFB, size = %d\n", size);
        list_remove(&fs_info->fs_link);
        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.
     */
    ipc_answer_2(callid, EOK, (ipcarg_t) plb,
        (ipcarg_t) (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 = (int) atomic_postinc(&fs_handle_next);
    ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);
   
    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(int 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.
 */
int 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 (strcmp(fs->vfs_info.name, name) == 0) { /* XXX: strncmp() */
            handle = fs->fs_handle;
            break;
        }
    }
    if (lock)
        futex_up(&fs_head_futex);
    return handle;
}
 
/**
 * @}
 */
 

Rev 2600	Rev 2619
1	/*	1	/*
2	* Copyright (c) 2007 Jakub Jermar	2	* Copyright (c) 2007 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 VFS_REGISTER method.	35	* @brief VFS_REGISTER method.
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 <as.h>	49	#include <as.h>
50	#include <libadt/list.h>	50	#include <libadt/list.h>
51	#include <assert.h>	51	#include <assert.h>
52	#include "vfs.h"	52	#include "vfs.h"
53		53
54	atomic_t fs_head_futex = FUTEX_INITIALIZER;	54	atomic_t fs_head_futex = FUTEX_INITIALIZER;
55	link_t fs_head;	55	link_t fs_head;
56		56
57	atomic_t fs_handle_next = {	57	atomic_t fs_handle_next = {
58	.count = 1	58	.count = 1
59	};	59	};
60		60
61	/** Verify the VFS info structure.	61	/** Verify the VFS info structure.
62	*	62	*
63	* @param info Info structure to be verified.	63	* @param info Info structure to be verified.
64	*	64	*
65	* @return Non-zero if the info structure is sane, zero otherwise.	65	* @return Non-zero if the info structure is sane, zero otherwise.
66	*/	66	*/
67	static bool vfs_info_sane(vfs_info_t *info)	67	static bool vfs_info_sane(vfs_info_t *info)
68	{	68	{
69	int i;	69	int i;
70		70
71	/*	71	/*
72	* Check if the name is non-empty and is composed solely of ASCII	72	* Check if the name is non-empty and is composed solely of ASCII
73	* characters [a-z]+[a-z0-9_-]*.	73	* characters [a-z]+[a-z0-9_-]*.
74	*/	74	*/
75	if (!islower(info->name[0])) {	75	if (!islower(info->name[0])) {
76	dprintf("The name doesn't start with a lowercase character.\n");	76	dprintf("The name doesn't start with a lowercase character.\n");
77	return false;	77	return false;
78	}	78	}
79	for (i = 1; i < FS_NAME_MAXLEN; i++) {	79	for (i = 1; i < FS_NAME_MAXLEN; i++) {
80	if (!(islower(info->name[i]) \|\| isdigit(info->name[i])) &&	80	if (!(islower(info->name[i]) \|\| isdigit(info->name[i])) &&
81	(info->name[i] != '-') && (info->name[i] != '_')) {	81	(info->name[i] != '-') && (info->name[i] != '_')) {
82	if (info->name[i] == '\0') {	82	if (info->name[i] == '\0') {
83	break;	83	break;
84	} else {	84	} else {
85	dprintf("The name contains illegal "	85	dprintf("The name contains illegal "
86	"characters.\n");	86	"characters.\n");
87	return false;	87	return false;
88	}	88	}
89	}	89	}
90	}	90	}
91		91
92		92
93	/*	93	/*
94	* Check if the FS implements mandatory VFS operations.	94	* Check if the FS implements mandatory VFS operations.
95	*/	95	*/
96	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED) {	96	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED) {
97	dprintf("Operation VFS_REGISTER not defined by the client.\n");	97	dprintf("Operation VFS_REGISTER not defined by the client.\n");
98	return false;	98	return false;
99	}	99	}
100	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED) {	100	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED) {
101	dprintf("Operation VFS_MOUNT not defined by the client.\n");	101	dprintf("Operation VFS_MOUNT not defined by the client.\n");
102	return false;	102	return false;
103	}	103	}
104	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED) {	104	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED) {
105	dprintf("Operation VFS_UNMOUNT not defined by the client.\n");	105	dprintf("Operation VFS_UNMOUNT not defined by the client.\n");
106	return false;	106	return false;
107	}	107	}
108	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] != VFS_OP_DEFINED) {	108	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] != VFS_OP_DEFINED) {
109	dprintf("Operation VFS_LOOKUP not defined by the client.\n");	109	dprintf("Operation VFS_LOOKUP not defined by the client.\n");
110	return false;	110	return false;
111	}	111	}
112	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED) {	112	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED) {
113	dprintf("Operation VFS_OPEN not defined by the client.\n");	113	dprintf("Operation VFS_OPEN not defined by the client.\n");
114	return false;	114	return false;
115	}	115	}
116	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED) {	116	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED) {
117	dprintf("Operation VFS_CLOSE not defined by the client.\n");	117	dprintf("Operation VFS_CLOSE not defined by the client.\n");
118	return false;	118	return false;
119	}	119	}
120	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED) {	120	if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED) {
121	dprintf("Operation VFS_READ not defined by the client.\n");	121	dprintf("Operation VFS_READ not defined by the client.\n");
122	return false;	122	return false;
123	}	123	}
124		124
125	/*	125	/*
126	* Check if each operation is either not defined, defined or default.	126	* Check if each operation is either not defined, defined or default.
127	*/	127	*/
128	for (i = VFS_FIRST; i < VFS_LAST; i++) {	128	for (i = VFS_FIRST; i < VFS_LAST; i++) {
129	if ((info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_NULL) &&	129	if ((info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_NULL) &&
130	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFAULT) &&	130	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFAULT) &&
131	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFINED)) {	131	(info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFINED)) {
132	dprintf("Operation info not understood.\n");	132	dprintf("Operation info not understood.\n");
133	return false;	133	return false;
134	}	134	}
135	}	135	}
136	return true;	136	return true;
137	}	137	}
138		138
139	/** VFS_REGISTER protocol function.	139	/** VFS_REGISTER protocol function.
140	*	140	*
141	* @param rid Hash of the call with the request.	141	* @param rid Hash of the call with the request.
142	* @param request Call structure with the request.	142	* @param request Call structure with the request.
143	*/	143	*/
144	void vfs_register(ipc_callid_t rid, ipc_call_t *request)	144	void vfs_register(ipc_callid_t rid, ipc_call_t *request)
145	{	145	{
146	ipc_callid_t callid;	146	ipc_callid_t callid;
147	ipc_call_t call;	147	ipc_call_t call;
148	int rc;	148	int rc;
149	size_t size;	149	size_t size;
150		150
151	dprintf("Processing VFS_REGISTER request received from %p.\n",	151	dprintf("Processing VFS_REGISTER request received from %p.\n",
152	request->in_phone_hash);	152	request->in_phone_hash);
153		153
154	/*	154	/*
155	* The first call has to be IPC_M_DATA_SEND in which we receive the	155	* The first call has to be IPC_M_DATA_SEND in which we receive the
156	* VFS info structure from the client FS.	156	* VFS info structure from the client FS.
157	*/	157	*/
158	if (!ipc_data_receive(&callid, &call, NULL, &size)) {	158	if (!ipc_data_receive(&callid, NULL, &size)) {
159	/*	159	/*
160	* The client doesn't obey the same protocol as we do.	160	* The client doesn't obey the same protocol as we do.
161	*/	161	*/
162	dprintf("Receiving of VFS info failed.\n");	162	dprintf("Receiving of VFS info failed.\n");
163	ipc_answer_fast_0(callid, EINVAL);	163	ipc_answer_0(callid, EINVAL);
164	ipc_answer_fast_0(rid, EINVAL);	164	ipc_answer_0(rid, EINVAL);
165	return;	165	return;
166	}	166	}
167		167
168	dprintf("VFS info received, size = %d\n", size);	168	dprintf("VFS info received, size = %d\n", size);
169		169
170	/*	170	/*
171	* We know the size of the VFS info structure. See if the client	171	* We know the size of the VFS info structure. See if the client
172	* understands this easy concept too.	172	* understands this easy concept too.
173	*/	173	*/
174	if (size != sizeof(vfs_info_t)) {	174	if (size != sizeof(vfs_info_t)) {
175	/*	175	/*
176	* The client is sending us something, which cannot be	176	* The client is sending us something, which cannot be
177	* the info structure.	177	* the info structure.
178	*/	178	*/
179	dprintf("Received VFS info has bad size.\n");	179	dprintf("Received VFS info has bad size.\n");
180	ipc_answer_fast_0(callid, EINVAL);	180	ipc_answer_0(callid, EINVAL);
181	ipc_answer_fast_0(rid, EINVAL);	181	ipc_answer_0(rid, EINVAL);
182	return;	182	return;
183	}	183	}
184		184
185	/*	185	/*
186	* Allocate and initialize a buffer for the fs_info structure.	186	* Allocate and initialize a buffer for the fs_info structure.
187	*/	187	*/
188	fs_info_t *fs_info;	188	fs_info_t *fs_info;
189	fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));	189	fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
190	if (!fs_info) {	190	if (!fs_info) {
191	dprintf("Could not allocate memory for FS info.\n");	191	dprintf("Could not allocate memory for FS info.\n");
192	ipc_answer_fast_0(callid, ENOMEM);	192	ipc_answer_0(callid, ENOMEM);
193	ipc_answer_fast_0(rid, ENOMEM);	193	ipc_answer_0(rid, ENOMEM);
194	return;	194	return;
195	}	195	}
196	link_initialize(&fs_info->fs_link);	196	link_initialize(&fs_info->fs_link);
197		197
198	rc = ipc_data_deliver(callid, &call, &fs_info->vfs_info, size);	198	rc = ipc_data_deliver(callid, &fs_info->vfs_info, size);
199	if (rc != EOK) {	199	if (rc != EOK) {
200	dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",	200	dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
201	rc);	201	rc);
202	free(fs_info);	202	free(fs_info);
203	ipc_answer_fast_0(callid, rc);	203	ipc_answer_0(callid, rc);
204	ipc_answer_fast_0(rid, rc);	204	ipc_answer_0(rid, rc);
205	return;	205	return;
206	}	206	}
207		207
208	dprintf("VFS info delivered.\n");	208	dprintf("VFS info delivered.\n");
209		209
210	if (!vfs_info_sane(&fs_info->vfs_info)) {	210	if (!vfs_info_sane(&fs_info->vfs_info)) {
211	free(fs_info);	211	free(fs_info);
212	ipc_answer_fast_0(callid, EINVAL);	212	ipc_answer_0(callid, EINVAL);
213	ipc_answer_fast_0(rid, EINVAL);	213	ipc_answer_0(rid, EINVAL);
214	return;	214	return;
215	}	215	}
216		216
217	futex_down(&fs_head_futex);	217	futex_down(&fs_head_futex);
218		218
219	/*	219	/*
220	* Check for duplicit registrations.	220	* Check for duplicit registrations.
221	*/	221	*/
222	if (fs_name_to_handle(fs_info->vfs_info.name, false)) {	222	if (fs_name_to_handle(fs_info->vfs_info.name, false)) {
223	/*	223	/*
224	* We already register a fs like this.	224	* We already register a fs like this.
225	*/	225	*/
226	dprintf("FS is already registered.\n");	226	dprintf("FS is already registered.\n");
227	futex_up(&fs_head_futex);	227	futex_up(&fs_head_futex);
228	free(fs_info);	228	free(fs_info);
229	ipc_answer_fast_0(callid, EEXISTS);	229	ipc_answer_0(callid, EEXISTS);
230	ipc_answer_fast_0(rid, EEXISTS);	230	ipc_answer_0(rid, EEXISTS);
231	return;	231	return;
232	}	232	}
233		233
234	/*	234	/*
235	* Add fs_info to the list of registered FS's.	235	* Add fs_info to the list of registered FS's.
236	*/	236	*/
237	dprintf("Inserting FS into the list of registered file systems.\n");	237	dprintf("Inserting FS into the list of registered file systems.\n");
238	list_append(&fs_info->fs_link, &fs_head);	238	list_append(&fs_info->fs_link, &fs_head);
239		239
240	/*	240	/*
241	* Now we want the client to send us the IPC_M_CONNECT_TO_ME call so	241	* Now we want the client to send us the IPC_M_CONNECT_TO_ME call so
242	* that a callback connection is created and we have a phone through	242	* that a callback connection is created and we have a phone through
243	* which to forward VFS requests to it.	243	* which to forward VFS requests to it.
244	*/	244	*/
245	callid = async_get_call(&call);	245	callid = async_get_call(&call);
246	if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {	246	if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
247	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));	247	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
248	list_remove(&fs_info->fs_link);	248	list_remove(&fs_info->fs_link);
249	futex_up(&fs_head_futex);	249	futex_up(&fs_head_futex);
250	free(fs_info);	250	free(fs_info);
251	ipc_answer_fast_0(callid, EINVAL);	251	ipc_answer_0(callid, EINVAL);
252	ipc_answer_fast_0(rid, EINVAL);	252	ipc_answer_0(rid, EINVAL);
253	return;	253	return;
254	}	254	}
255	fs_info->phone = IPC_GET_ARG3(call);	255	fs_info->phone = IPC_GET_ARG3(call);
256	ipc_answer_fast_0(callid, EOK);	256	ipc_answer_0(callid, EOK);
257		257
258	dprintf("Callback connection to FS created.\n");	258	dprintf("Callback connection to FS created.\n");
259		259
260	/*	260	/*
261	* The client will want us to send him the address space area with PLB.	261	* The client will want us to send him the address space area with PLB.
262	*/	262	*/
263	callid = async_get_call(&call);	263	callid = async_get_call(&call);
264	if (IPC_GET_METHOD(call) != IPC_M_AS_AREA_RECV) {	264	if (IPC_GET_METHOD(call) != IPC_M_AS_AREA_RECV) {
265	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));	265	dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
266	list_remove(&fs_info->fs_link);	266	list_remove(&fs_info->fs_link);
267	futex_up(&fs_head_futex);	267	futex_up(&fs_head_futex);
268	ipc_hangup(fs_info->phone);	268	ipc_hangup(fs_info->phone);
269	free(fs_info);	269	free(fs_info);
270	ipc_answer_fast_0(callid, EINVAL);	270	ipc_answer_0(callid, EINVAL);
271	ipc_answer_fast_0(rid, EINVAL);	271	ipc_answer_0(rid, EINVAL);
272	return;	272	return;
273	}	273	}
274		274
275	/*	275	/*
276	* We can only send the client address space area PLB_SIZE bytes long.	276	* We can only send the client address space area PLB_SIZE bytes long.
277	*/	277	*/
278	size = IPC_GET_ARG2(call);	278	size = IPC_GET_ARG2(call);
279	if (size != PLB_SIZE) {	279	if (size != PLB_SIZE) {
280	dprintf("Client suggests wrong size of PFB, size = %d\n", size);	280	dprintf("Client suggests wrong size of PFB, size = %d\n", size);
281	list_remove(&fs_info->fs_link);	281	list_remove(&fs_info->fs_link);
282	futex_up(&fs_head_futex);	282	futex_up(&fs_head_futex);
283	ipc_hangup(fs_info->phone);	283	ipc_hangup(fs_info->phone);
284	free(fs_info);	284	free(fs_info);
285	ipc_answer_fast_0(callid, EINVAL);	285	ipc_answer_0(callid, EINVAL);
286	ipc_answer_fast_0(rid, EINVAL);	286	ipc_answer_0(rid, EINVAL);
287	return;	287	return;
288	}	288	}
289		289
290	/*	290	/*
291	* Commit to read-only sharing the PLB with the client.	291	* Commit to read-only sharing the PLB with the client.
292	*/	292	*/
293	ipc_answer_fast(callid, EOK, (ipcarg_t) plb,	293	ipc_answer_2(callid, EOK, (ipcarg_t) plb,
294	(ipcarg_t) (AS_AREA_READ \| AS_AREA_CACHEABLE));	294	(ipcarg_t) (AS_AREA_READ \| AS_AREA_CACHEABLE));
295		295
296	dprintf("Sharing PLB.\n");	296	dprintf("Sharing PLB.\n");
297		297
298	/*	298	/*
299	* That was it. The FS has been registered.	299	* That was it. The FS has been registered.
300	* In reply to the VFS_REGISTER request, we assign the client file	300	* In reply to the VFS_REGISTER request, we assign the client file
301	* system a global file system handle.	301	* system a global file system handle.
302	*/	302	*/
303	fs_info->fs_handle = (int) atomic_postinc(&fs_handle_next);	303	fs_info->fs_handle = (int) atomic_postinc(&fs_handle_next);
304	ipc_answer_fast_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);	304	ipc_answer_1(rid, EOK, (ipcarg_t) fs_info->fs_handle);
305		305
306	futex_up(&fs_head_futex);	306	futex_up(&fs_head_futex);
307		307
308	dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",	308	dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
309	FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);	309	FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);
310	}	310	}
311		311
312	/** For a given file system handle, implement policy for allocating a phone.	312	/** For a given file system handle, implement policy for allocating a phone.
313	*	313	*
314	* @param handle File system handle.	314	* @param handle File system handle.
315	*	315	*
316	* @return Phone over which a multi-call request can be safely	316	* @return Phone over which a multi-call request can be safely
317	* sent. Return 0 if no phone was found.	317	* sent. Return 0 if no phone was found.
318	*/	318	*/
319	int vfs_grab_phone(int handle)	319	int vfs_grab_phone(int handle)
320	{	320	{
321	/*	321	/*
322	* For now, we don't try to be very clever and very fast.	322	* For now, we don't try to be very clever and very fast.
323	* We simply lookup the phone in the fs_head list. We currently don't	323	* We simply lookup the phone in the fs_head list. We currently don't
324	* open any additional phones (even though that itself would be pretty	324	* open any additional phones (even though that itself would be pretty
325	* straightforward; housekeeping multiple open phones to a FS task would	325	* straightforward; housekeeping multiple open phones to a FS task would
326	* be more demanding). Instead, we simply take the respective	326	* be more demanding). Instead, we simply take the respective
327	* phone_futex and keep it until vfs_release_phone().	327	* phone_futex and keep it until vfs_release_phone().
328	*/	328	*/
329	futex_down(&fs_head_futex);	329	futex_down(&fs_head_futex);
330	link_t *cur;	330	link_t *cur;
331	fs_info_t *fs;	331	fs_info_t *fs;
332	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	332	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
333	fs = list_get_instance(cur, fs_info_t, fs_link);	333	fs = list_get_instance(cur, fs_info_t, fs_link);
334	if (fs->fs_handle == handle) {	334	if (fs->fs_handle == handle) {
335	futex_up(&fs_head_futex);	335	futex_up(&fs_head_futex);
336	/*	336	/*
337	* For now, take the futex unconditionally.	337	* For now, take the futex unconditionally.
338	* Oh yeah, serialization rocks.	338	* Oh yeah, serialization rocks.
339	* It will be up'ed in vfs_release_phone().	339	* It will be up'ed in vfs_release_phone().
340	*/	340	*/
341	futex_down(&fs->phone_futex);	341	futex_down(&fs->phone_futex);
342	/*	342	/*
343	* Avoid deadlock with other fibrils in the same thread	343	* Avoid deadlock with other fibrils in the same thread
344	* by disabling fibril preemption.	344	* by disabling fibril preemption.
345	*/	345	*/
346	fibril_inc_sercount();	346	fibril_inc_sercount();
347	return fs->phone;	347	return fs->phone;
348	}	348	}
349	}	349	}
350	futex_up(&fs_head_futex);	350	futex_up(&fs_head_futex);
351	return 0;	351	return 0;
352	}	352	}
353		353
354	/** Tell VFS that the phone is in use for any request.	354	/** Tell VFS that the phone is in use for any request.
355	*	355	*
356	* @param phone Phone to FS task.	356	* @param phone Phone to FS task.
357	*/	357	*/
358	void vfs_release_phone(int phone)	358	void vfs_release_phone(int phone)
359	{	359	{
360	bool found = false;	360	bool found = false;
361		361
362	/*	362	/*
363	* Undo the fibril_inc_sercount() done in vfs_grab_phone().	363	* Undo the fibril_inc_sercount() done in vfs_grab_phone().
364	*/	364	*/
365	fibril_dec_sercount();	365	fibril_dec_sercount();
366		366
367	futex_down(&fs_head_futex);	367	futex_down(&fs_head_futex);
368	link_t *cur;	368	link_t *cur;
369	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	369	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
370	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);	370	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
371	if (fs->phone == phone) {	371	if (fs->phone == phone) {
372	found = true;	372	found = true;
373	futex_up(&fs_head_futex);	373	futex_up(&fs_head_futex);
374	futex_up(&fs->phone_futex);	374	futex_up(&fs->phone_futex);
375	return;	375	return;
376	}	376	}
377	}	377	}
378	futex_up(&fs_head_futex);	378	futex_up(&fs_head_futex);
379		379
380	/*	380	/*
381	* Not good to get here.	381	* Not good to get here.
382	*/	382	*/
383	assert(found == true);	383	assert(found == true);
384	}	384	}
385		385
386	/** Convert file system name to its handle.	386	/** Convert file system name to its handle.
387	*	387	*
388	* @param name File system name.	388	* @param name File system name.
389	* @param lock If true, the function will down and up the	389	* @param lock If true, the function will down and up the
390	* fs_head_futex.	390	* fs_head_futex.
391	*	391	*
392	* @return File system handle or zero if file system not found.	392	* @return File system handle or zero if file system not found.
393	*/	393	*/
394	int fs_name_to_handle(char *name, bool lock)	394	int fs_name_to_handle(char *name, bool lock)
395	{	395	{
396	int handle = 0;	396	int handle = 0;
397		397
398	if (lock)	398	if (lock)
399	futex_down(&fs_head_futex);	399	futex_down(&fs_head_futex);
400	link_t *cur;	400	link_t *cur;
401	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {	401	for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
402	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);	402	fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
403	if (strcmp(fs->vfs_info.name, name) == 0) { /* XXX: strncmp() */	403	if (strcmp(fs->vfs_info.name, name) == 0) { /* XXX: strncmp() */
404	handle = fs->fs_handle;	404	handle = fs->fs_handle;
405	break;	405	break;
406	}	406	}
407	}	407	}
408	if (lock)	408	if (lock)
409	futex_up(&fs_head_futex);	409	futex_up(&fs_head_futex);
410	return handle;	410	return handle;
411	}	411	}
412		412
413	/**	413	/**
414	* @}	414	* @}
415	*/	415	*/
416		416

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(root)/trunk/uspace/srv/vfs/vfs_register.c – Rev 2600 → 2619