Subversion Repositories HelenOS

Rev

Rev 2542 | Go to most recent revision | Only display areas with differences | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 2542 Rev 2544
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.c
 34 
 * @file    vfs.c
35 
 * @brief   VFS_LOOKUP method and Path Lookup Buffer code.
 35 
 * @brief   VFS_LOOKUP method and Path Lookup Buffer code.
36 
 */
 36 
 */
37 
 
 37 
 
38 
#include <ipc/ipc.h>
 38 
#include <ipc/ipc.h>
39 
#include <async.h>
 39 
#include <async.h>
40 
#include <errno.h>
 40 
#include <errno.h>
41 
#include <stdlib.h>
 41 
#include <stdlib.h>
42 
#include <string.h>
 42 
#include <string.h>
43 
#include <bool.h>
 43 
#include <bool.h>
44 
#include <futex.h>
 44 
#include <futex.h>
45 
#include <libadt/list.h>
 45 
#include <libadt/list.h>
46 
#include "vfs.h"
 46 
#include "vfs.h"
47 
 
 47 
 
- 
 
 48 
#define min(a, b)   ((a) < (b) ? (a) : (b))
- 
 
 49 
 
48 
atomic_t plb_futex = FUTEX_INITIALIZER;
 50 
atomic_t plb_futex = FUTEX_INITIALIZER;
49 
link_t plb_head;
 51 
link_t plb_head;    /**< PLB entry ring buffer. */
50 
uint8_t *plb = NULL;
 52 
uint8_t *plb = NULL;
51 
 
 53 
 
52 
void vfs_lookup(ipc_callid_t rid, ipc_call_t *request)
 54 
int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result)
53 
{
 55 
{
- 
 
 56 
    if (!len)
- 
 
 57 
        return EINVAL;
- 
 
 58 
 
54 
    if (!rootfs)
 59 
    if (!rootfs)
- 
 
 60 
        return ENOENT;
- 
 
 61 
   
- 
 
 62 
    futex_down(&plb_futex);
- 
 
 63 
 
- 
 
 64 
    plb_entry_t entry;
- 
 
 65 
    link_initialize(&entry.plb_link);
- 
 
 66 
    entry.len = len;
- 
 
 67 
 
- 
 
 68 
    off_t first;    /* the first free index */
- 
 
 69 
    off_t last; /* the last free index */
- 
 
 70 
 
- 
 
 71 
    if (list_empty(&plb_head)) {
- 
 
 72 
        first = 0;
- 
 
 73 
        last = PLB_SIZE - 1;
- 
 
 74 
    } else {
- 
 
 75 
        plb_entry_t *oldest = list_get_instance(plb_head.next,
- 
 
 76 
            plb_entry_t, plb_link);
- 
 
 77 
        plb_entry_t *newest = list_get_instance(plb_head.prev,
- 
 
 78 
            plb_entry_t, plb_link);
- 
 
 79 
 
- 
 
 80 
        first = (newest->index + newest->len) % PLB_SIZE;
- 
 
 81 
        last = (oldest->index - 1) % PLB_SIZE;
- 
 
 82 
    }
- 
 
 83 
 
- 
 
 84 
    if (first <= last) {
- 
 
 85 
        if ((last - first) + 1 < len) {
- 
 
 86 
            /*
- 
 
 87 
             * The buffer cannot absorb the path.
- 
 
 88 
             */
- 
 
 89 
            futex_up(&plb_futex);
- 
 
 90 
            return ELIMIT;
- 
 
 91 
        }
- 
 
 92 
    } else {
- 
 
 93 
        if (PLB_SIZE - ((first - last) + 1) < len) {
- 
 
 94 
            /*
- 
 
 95 
             * The buffer cannot absorb the path.
- 
 
 96 
             */
- 
 
 97 
            futex_up(&plb_futex);
- 
 
 98 
            return ELIMIT;
- 
 
 99 
        }
- 
 
 100 
    }
- 
 
 101 
 
- 
 
 102 
    /*
- 
 
 103 
     * We know the first free index in PLB and we also know that there is
- 
 
 104 
     * enough space in the buffer to hold our path.
- 
 
 105 
     */
- 
 
 106 
 
- 
 
 107 
    entry.index = first;
- 
 
 108 
    entry.len = len;
- 
 
 109 
 
- 
 
 110 
    /*
- 
 
 111 
     * Claim PLB space by inserting the entry into the PLB entry ring
- 
 
 112 
     * buffer.
- 
 
 113 
     */
- 
 
 114 
    list_append(&entry.plb_link, &plb_head);
- 
 
 115 
   
- 
 
 116 
    futex_up(&plb_futex);
- 
 
 117 
 
- 
 
 118 
    /*
- 
 
 119 
     * Copy the path into PLB.
- 
 
 120 
     */
- 
 
 121 
    size_t cnt1 = min(len, (PLB_SIZE - first) + 1);
- 
 
 122 
    size_t cnt2 = len - cnt1;
- 
 
 123 
   
55 
        ipc_answer_fast(rid, ENOENT, 0, 0);
 124 
    memcpy(&plb[first], path, cnt1);
- 
 
 125 
    memcpy(plb, &path[cnt1], cnt2);
- 
 
 126 
 
- 
 
 127 
    ipc_call_t answer;
- 
 
 128 
    int phone = 0;      /* TODO */
- 
 
 129 
    aid_t req = async_send_2(phone, VFS_LOOKUP, (ipcarg_t) first,
- 
 
 130 
        (ipcarg_t) last, &answer);
- 
 
 131 
 
- 
 
 132 
    ipcarg_t rc;
- 
 
 133 
    async_wait_for(req, &rc);
- 
 
 134 
 
- 
 
 135 
    futex_down(&plb_futex);
- 
 
 136 
    list_remove(&entry.plb_link);
- 
 
 137 
    futex_up(&plb_futex);
- 
 
 138 
 
- 
 
 139 
    if (rc == EOK) {
- 
 
 140 
        result->fs_handle = (int) IPC_GET_ARG1(answer);
- 
 
 141 
        result->dev_handle = (int) IPC_GET_ARG2(answer);
- 
 
 142 
        result->index = (int) IPC_GET_ARG3(answer);
- 
 
 143 
    }
- 
 
 144 
 
- 
 
 145 
    return rc;
56 
}
 146 
}
57 
 
 147 
 
58 
/**
 148 
/**
59 
 * @}
 149 
 * @}
60 
 */
 150 
 */
61 
 
 151