WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_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    fat_ops.c
 * @brief   Implementation of VFS operations for the FAT file system server.
 */
 
#include "fat.h"
#include "../../vfs/vfs.h"
#include <libfs.h>
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <string.h>
#include <byteorder.h>
#include <libadt/hash_table.h>
#include <libadt/list.h>
#include <assert.h>
#include <futex.h>
 
#define BS_BLOCK        0
 
#define FIN_KEY_DEV_HANDLE  0
#define FIN_KEY_INDEX       1
 
/** Hash table of FAT in-core nodes. */
hash_table_t fin_hash;
 
/** List of free FAT in-core nodes. */
link_t ffn_head;
 
#define FAT_NAME_LEN        8
#define FAT_EXT_LEN     3
 
#define FAT_PAD         ' ' 
 
#define FAT_DENTRY_UNUSED   0x00
#define FAT_DENTRY_E5_ESC   0x05
#define FAT_DENTRY_DOT      0x2e
#define FAT_DENTRY_ERASED   0xe5
 
static void dentry_name_canonify(fat_dentry_t *d, char *buf)
{
    int i;
 
    for (i = 0; i < FAT_NAME_LEN; i++) {
        if (d->name[i] == FAT_PAD) {
            buf++;
            break;
        }
        if (d->name[i] == FAT_DENTRY_E5_ESC)
            *buf++ = 0xe5;
        else
            *buf++ = d->name[i];
    }
    if (d->ext[0] != FAT_PAD)
        *buf++ = '.';
    for (i = 0; i < FAT_EXT_LEN; i++) {
        if (d->ext[i] == FAT_PAD) {
            *buf = '\0';
            return;
        }
        if (d->ext[i] == FAT_DENTRY_E5_ESC)
            *buf++ = 0xe5;
        else
            *buf++ = d->ext[i];
    }
}
 
/* TODO and also move somewhere else */
typedef struct {
    void *data;
} block_t;
 
static block_t *block_get(dev_handle_t dev_handle, off_t offset)
{
    return NULL;    /* TODO */
}
 
static void block_put(block_t *block)
{
    /* TODO */
}
 
#define FAT_BS(b)       ((fat_bs_t *)((b)->data))
 
#define FAT_CLST_RES0   0x0000
#define FAT_CLST_RES1   0x0001  /* internally used to mark root directory */
#define FAT_CLST_FIRST  0x0002
#define FAT_CLST_BAD    0xfff7
#define FAT_CLST_LAST1  0xfff8
#define FAT_CLST_LAST8  0xffff
 
#define fat_block_get(np, off) \
    _fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))
 
static block_t *
_fat_block_get(dev_handle_t dev_handle, fat_cluster_t fc, off_t offset)
{
    block_t *bb;
    block_t *b;
    unsigned bps;
    unsigned spc;
    unsigned rscnt;     /* block address of the first FAT */
    unsigned fatcnt;
    unsigned rde;
    unsigned rds;       /* root directory size */
    unsigned sf;
    unsigned ssa;       /* size of the system area */
    unsigned clusters;
    fat_cluster_t clst = fc;
    unsigned i;
 
    bb = block_get(dev_handle, BS_BLOCK);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    spc = FAT_BS(bb)->spc;
    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
    fatcnt = FAT_BS(bb)->fatcnt;
    rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
    sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
    block_put(bb);
 
    rds = (sizeof(fat_dentry_t) * rde) / bps;
    rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
    ssa = rscnt + fatcnt * sf + rds;
 
    if (fc == FAT_CLST_RES1) {
        /* root directory special case */
        assert(offset < rds);
 
        b = block_get(dev_handle, rscnt + fatcnt * sf + offset);
        return b;
    }
 
    clusters = offset / spc;
    for (i = 0; i < clusters; i++) {
        unsigned fsec;  /* sector offset relative to FAT1 */
        unsigned fidx;  /* FAT1 entry index */
 
        assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
        fidx = clst % (bps / sizeof(fat_cluster_t));
        /* read FAT1 */
        b = block_get(dev_handle, rscnt + fsec);
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
        assert(clst != FAT_CLST_BAD);
        assert(clst < FAT_CLST_LAST1);
        block_put(b);
    }
 
    b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
        offset % spc);
 
    return b;
}
 
static void fat_node_initialize(fat_node_t *node)
{
    node->idx = NULL;
    node->type = 0;
    link_initialize(&node->fin_link);
    link_initialize(&node->ffn_link);
    node->size = 0;
    node->lnkcnt = 0;
    node->refcnt = 0;
    node->dirty = false;
}
 
static uint16_t fat_bps_get(dev_handle_t dev_handle)
{
    block_t *bb;
    uint16_t bps;
   
    bb = block_get(dev_handle, BS_BLOCK);
    assert(bb != NULL);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    block_put(bb);
 
    return bps;
}
 
typedef enum {
    FAT_DENTRY_SKIP,
    FAT_DENTRY_LAST,
    FAT_DENTRY_VALID
} fat_dentry_clsf_t;
 
static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
{
    if (d->attr & FAT_ATTR_VOLLABEL) {
        /* volume label entry */
        return FAT_DENTRY_SKIP;
    }
    if (d->name[0] == FAT_DENTRY_ERASED) {
        /* not-currently-used entry */
        return FAT_DENTRY_SKIP;
    }
    if (d->name[0] == FAT_DENTRY_UNUSED) {
        /* never used entry */
        return FAT_DENTRY_LAST;
    }
    if (d->name[0] == FAT_DENTRY_DOT) {
        /*
         * Most likely '.' or '..'.
         * It cannot occur in a regular file name.
         */
        return FAT_DENTRY_SKIP;
    }
    return FAT_DENTRY_VALID;
}
 
static void fat_sync_node(fat_node_t *node)
{
    /* TODO */
}
 
/** Instantiate a FAT in-core node. */
 
static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
{
    fat_idx_t *idx;
    block_t *b;
    fat_dentry_t *d;
    fat_node_t *nodep;
    unsigned bps;
    unsigned dps;
 
    idx = fat_idx_get_by_index(dev_handle, index);
    if (!idx)
        return NULL;
 
    if (idx->nodep) {
        /*
         * We are lucky.
         * The node is already instantiated in memory.
         */
        idx->nodep->refcnt++;
        return idx->nodep;
    }
 
    /*
     * We must instantiate the node from the file system.
     */
   
    assert(idx->pfc);
 
    nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
    if (!nodep)
        return NULL;
    fat_node_initialize(nodep);
 
    bps = fat_bps_get(dev_handle);
    dps = bps / sizeof(fat_dentry_t);
 
    b = _fat_block_get(dev_handle, idx->pfc,
        (idx->pdi * sizeof(fat_dentry_t)) / bps);
 
    assert(b);
 
    d = ((fat_dentry_t *)b->data) + (idx->pdi % dps);
    /* XXX */
}
 
static void fat_node_put(void *node)
{
    /* TODO */
}
 
static void *fat_create(int flags)
{
    return NULL;    /* not supported at the moment */
}
 
static int fat_destroy(void *node)
{
    return ENOTSUP; /* not supported at the moment */
}
 
static bool fat_link(void *prnt, void *chld, const char *name)
{
    return false;   /* not supported at the moment */
}
 
static int fat_unlink(void *prnt, void *chld)
{
    return ENOTSUP; /* not supported at the moment */
}
 
static void *fat_match(void *prnt, const char *component)
{
    fat_node_t *parentp = (fat_node_t *)prnt;
    char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
    unsigned i, j;
    unsigned bps;       /* bytes per sector */
    unsigned dps;       /* dentries per sector */
    unsigned blocks;
    fat_dentry_t *d;
    block_t *b;
 
    bps = fat_bps_get(parentp->idx->dev_handle);
    dps = bps / sizeof(fat_dentry_t);
    blocks = parentp->size / bps + (parentp->size % bps != 0);
    for (i = 0; i < blocks; i++) {
        unsigned dentries;
       
        b = fat_block_get(parentp, i);
        dentries = (i == blocks - 1) ?
            parentp->size % sizeof(fat_dentry_t) :
            dps;
        for (j = 0; j < dentries; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                return NULL;
            default:
            case FAT_DENTRY_VALID:
                dentry_name_canonify(d, name);
                break;
            }
            if (strcmp(name, component) == 0) {
                /* hit */
                fat_idx_t *idx = fat_idx_get_by_pos(
                    parentp->idx->dev_handle, parentp->firstc,
                    i * dps + j);
                if (!idx) {
                    /*
                     * Can happen if memory is low or if we
                     * run out of 32-bit indices.
                     */
                    block_put(b);
                    return NULL;
                }
                void *node = fat_node_get(idx->dev_handle,
                    idx->index);
                block_put(b);
                return node;
            }
        }
        block_put(b);
    }
 
    return NULL;
}
 
static fs_index_t fat_index_get(void *node)
{
    fat_node_t *fnodep = (fat_node_t *)node;
    if (!fnodep)
        return 0;
    return fnodep->idx->index;
}
 
static size_t fat_size_get(void *node)
{
    return ((fat_node_t *)node)->size;
}
 
static unsigned fat_lnkcnt_get(void *node)
{
    return ((fat_node_t *)node)->lnkcnt;
}
 
static bool fat_has_children(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
    unsigned bps;
    unsigned dps;
    unsigned blocks;
    block_t *b;
    unsigned i, j;
 
    if (nodep->type != FAT_DIRECTORY)
        return false;
 
    bps = fat_bps_get(nodep->idx->dev_handle);
    dps = bps / sizeof(fat_dentry_t);
 
    blocks = nodep->size / bps + (nodep->size % bps != 0);
 
    for (i = 0; i < blocks; i++) {
        unsigned dentries;
        fat_dentry_t *d;
   
        b = fat_block_get(nodep, i);
        dentries = (i == blocks - 1) ?
            nodep->size % sizeof(fat_dentry_t) :
            dps;
        for (j = 0; j < dentries; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                return false;
            default:
            case FAT_DENTRY_VALID:
                block_put(b);
                return true;
            }
            block_put(b);
            return true;
        }
        block_put(b);
    }
 
    return false;
}
 
static void *fat_root_get(dev_handle_t dev_handle)
{
    return fat_node_get(dev_handle, 0); /* TODO */
}
 
static char fat_plb_get_char(unsigned pos)
{
    return fat_reg.plb_ro[pos % PLB_SIZE];
}
 
static bool fat_is_directory(void *node)
{
    return ((fat_node_t *)node)->type == FAT_DIRECTORY;
}
 
static bool fat_is_file(void *node)
{
    return ((fat_node_t *)node)->type == FAT_FILE;
}
 
/** libfs operations */
libfs_ops_t fat_libfs_ops = {
    .match = fat_match,
    .node_get = fat_node_get,
    .node_put = fat_node_put,
    .create = fat_create,
    .destroy = fat_destroy,
    .link = fat_link,
    .unlink = fat_unlink,
    .index_get = fat_index_get,
    .size_get = fat_size_get,
    .lnkcnt_get = fat_lnkcnt_get,
    .has_children = fat_has_children,
    .root_get = fat_root_get,
    .plb_get_char = fat_plb_get_char,
    .is_directory = fat_is_directory,
    .is_file = fat_is_file
};
 
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
}
 
/**
 * @}
 */
 

Rev 2890	Rev 2891
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 fat_ops.c	34	* @file fat_ops.c
35	* @brief Implementation of VFS operations for the FAT file system server.	35	* @brief Implementation of VFS operations for the FAT file system server.
36	*/	36	*/
37		37
38	#include "fat.h"	38	#include "fat.h"
39	#include "../../vfs/vfs.h"	39	#include "../../vfs/vfs.h"
40	#include <libfs.h>	40	#include <libfs.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 <string.h>	44	#include <string.h>
45	#include <byteorder.h>	45	#include <byteorder.h>
46	#include <libadt/hash_table.h>	46	#include <libadt/hash_table.h>
47	#include <libadt/list.h>	47	#include <libadt/list.h>
48	#include <assert.h>	48	#include <assert.h>
49	#include <futex.h>	49	#include <futex.h>
50		50
51	#define BS_BLOCK 0	51	#define BS_BLOCK 0
52		52
53	#define FIN_KEY_DEV_HANDLE 0	53	#define FIN_KEY_DEV_HANDLE 0
54	#define FIN_KEY_INDEX 1	54	#define FIN_KEY_INDEX 1
55		55
56	/** Hash table of FAT in-core nodes. */	56	/** Hash table of FAT in-core nodes. */
57	hash_table_t fin_hash;	57	hash_table_t fin_hash;
58		58
59	/** List of free FAT in-core nodes. */	59	/** List of free FAT in-core nodes. */
60	link_t ffn_head;	60	link_t ffn_head;
61		61
62	#define FAT_NAME_LEN 8	62	#define FAT_NAME_LEN 8
63	#define FAT_EXT_LEN 3	63	#define FAT_EXT_LEN 3
64		64
65	#define FAT_PAD ' '	65	#define FAT_PAD ' '
66		66
67	#define FAT_DENTRY_UNUSED 0x00	67	#define FAT_DENTRY_UNUSED 0x00
68	#define FAT_DENTRY_E5_ESC 0x05	68	#define FAT_DENTRY_E5_ESC 0x05
69	#define FAT_DENTRY_DOT 0x2e	69	#define FAT_DENTRY_DOT 0x2e
70	#define FAT_DENTRY_ERASED 0xe5	70	#define FAT_DENTRY_ERASED 0xe5
71		71
72	static void dentry_name_canonify(fat_dentry_t d, char buf)	72	static void dentry_name_canonify(fat_dentry_t d, char buf)
73	{	73	{
74	int i;	74	int i;
75		75
76	for (i = 0; i < FAT_NAME_LEN; i++) {	76	for (i = 0; i < FAT_NAME_LEN; i++) {
77	if (d->name[i] == FAT_PAD) {	77	if (d->name[i] == FAT_PAD) {
78	buf++;	78	buf++;
79	break;	79	break;
80	}	80	}
81	if (d->name[i] == FAT_DENTRY_E5_ESC)	81	if (d->name[i] == FAT_DENTRY_E5_ESC)
82	*buf++ = 0xe5;	82	*buf++ = 0xe5;
83	else	83	else
84	*buf++ = d->name[i];	84	*buf++ = d->name[i];
85	}	85	}
86	if (d->ext[0] != FAT_PAD)	86	if (d->ext[0] != FAT_PAD)
87	*buf++ = '.';	87	*buf++ = '.';
88	for (i = 0; i < FAT_EXT_LEN; i++) {	88	for (i = 0; i < FAT_EXT_LEN; i++) {
89	if (d->ext[i] == FAT_PAD) {	89	if (d->ext[i] == FAT_PAD) {
90	*buf = '\0';	90	*buf = '\0';
91	return;	91	return;
92	}	92	}
93	if (d->ext[i] == FAT_DENTRY_E5_ESC)	93	if (d->ext[i] == FAT_DENTRY_E5_ESC)
94	*buf++ = 0xe5;	94	*buf++ = 0xe5;
95	else	95	else
96	*buf++ = d->ext[i];	96	*buf++ = d->ext[i];
97	}	97	}
98	}	98	}
99		99
100	/* TODO and also move somewhere else */	100	/* TODO and also move somewhere else */
101	typedef struct {	101	typedef struct {
102	void *data;	102	void *data;
103	} block_t;	103	} block_t;
104		104
105	static block_t *block_get(dev_handle_t dev_handle, off_t offset)	105	static block_t *block_get(dev_handle_t dev_handle, off_t offset)
106	{	106	{
107	return NULL; /* TODO */	107	return NULL; /* TODO */
108	}	108	}
109		109
110	static void block_put(block_t *block)	110	static void block_put(block_t *block)
111	{	111	{
112	/* TODO */	112	/* TODO */
113	}	113	}
114		114
115	#define FAT_BS(b) ((fat_bs_t *)((b)->data))	115	#define FAT_BS(b) ((fat_bs_t *)((b)->data))
116		116
117	#define FAT_CLST_RES0 0x0000	117	#define FAT_CLST_RES0 0x0000
118	#define FAT_CLST_RES1 0x0001 /* internally used to mark root directory */	118	#define FAT_CLST_RES1 0x0001 /* internally used to mark root directory */
119	#define FAT_CLST_FIRST 0x0002	119	#define FAT_CLST_FIRST 0x0002
120	#define FAT_CLST_BAD 0xfff7	120	#define FAT_CLST_BAD 0xfff7
121	#define FAT_CLST_LAST1 0xfff8	121	#define FAT_CLST_LAST1 0xfff8
122	#define FAT_CLST_LAST8 0xffff	122	#define FAT_CLST_LAST8 0xffff
123		123
-		124	#define fat_block_get(np, off) \
-		125	_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))
-		126
-		127	static block_t *
124	static block_t fat_block_get(fat_node_t nodep, off_t offset)	128	_fat_block_get(dev_handle_t dev_handle, fat_cluster_t fc, off_t offset)
125	{	129	{
126	block_t *bb;	130	block_t *bb;
127	block_t *b;	131	block_t *b;
128	unsigned bps;	132	unsigned bps;
129	unsigned spc;	133	unsigned spc;
130	unsigned rscnt; /* block address of the first FAT */	134	unsigned rscnt; /* block address of the first FAT */
131	unsigned fatcnt;	135	unsigned fatcnt;
132	unsigned rde;	136	unsigned rde;
133	unsigned rds; /* root directory size */	137	unsigned rds; /* root directory size */
134	unsigned sf;	138	unsigned sf;
135	unsigned ssa; /* size of the system area */	139	unsigned ssa; /* size of the system area */
136	unsigned clusters;	140	unsigned clusters;
137	fat_cluster_t clst = nodep->firstc;	141	fat_cluster_t clst = fc;
138	unsigned i;	142	unsigned i;
139		143
140	bb = block_get(nodep->idx->dev_handle, BS_BLOCK);	144	bb = block_get(dev_handle, BS_BLOCK);
141	bps = uint16_t_le2host(FAT_BS(bb)->bps);	145	bps = uint16_t_le2host(FAT_BS(bb)->bps);
142	spc = FAT_BS(bb)->spc;	146	spc = FAT_BS(bb)->spc;
143	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);	147	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
144	fatcnt = FAT_BS(bb)->fatcnt;	148	fatcnt = FAT_BS(bb)->fatcnt;
145	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);	149	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
146	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);	150	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
147	block_put(bb);	151	block_put(bb);
148		152
149	rds = (sizeof(fat_dentry_t) * rde) / bps;	153	rds = (sizeof(fat_dentry_t) * rde) / bps;
150	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);	154	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
151	ssa = rscnt + fatcnt * sf + rds;	155	ssa = rscnt + fatcnt * sf + rds;
152		156
153	if (nodep->idx->index == FAT_CLST_RES1) {	157	if (fc == FAT_CLST_RES1) {
154	/* root directory special case */	158	/* root directory special case */
155	assert(offset < rds);	159	assert(offset < rds);
156	b = block_get(nodep->idx->dev_handle,	-
157	rscnt + fatcnt * sf + offset);	160	b = block_get(dev_handle, rscnt + fatcnt * sf + offset);
158	return b;	161	return b;
159	}	162	}
160		163
161	clusters = offset / spc;	164	clusters = offset / spc;
162	for (i = 0; i < clusters; i++) {	165	for (i = 0; i < clusters; i++) {
163	unsigned fsec; /* sector offset relative to FAT1 */	166	unsigned fsec; /* sector offset relative to FAT1 */
164	unsigned fidx; /* FAT1 entry index */	167	unsigned fidx; /* FAT1 entry index */
165		168
166	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);	169	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
167	fsec = (clst * sizeof(fat_cluster_t)) / bps;	170	fsec = (clst * sizeof(fat_cluster_t)) / bps;
168	fidx = clst % (bps / sizeof(fat_cluster_t));	171	fidx = clst % (bps / sizeof(fat_cluster_t));
169	/* read FAT1 */	172	/* read FAT1 */
170	b = block_get(nodep->idx->dev_handle, rscnt + fsec);	173	b = block_get(dev_handle, rscnt + fsec);
171	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);	174	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
172	assert(clst != FAT_CLST_BAD);	175	assert(clst != FAT_CLST_BAD);
173	assert(clst < FAT_CLST_LAST1);	176	assert(clst < FAT_CLST_LAST1);
174	block_put(b);	177	block_put(b);
175	}	178	}
176		179
177	b = block_get(nodep->idx->dev_handle, ssa +	180	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
178	(clst - FAT_CLST_FIRST) * spc + offset % spc);	181	offset % spc);
179		182
180	return b;	183	return b;
181	}	184	}
182		185
183	static void fat_node_initialize(fat_node_t *node)	186	static void fat_node_initialize(fat_node_t *node)
184	{	187	{
185	node->idx = NULL;	188	node->idx = NULL;
186	node->type = 0;	189	node->type = 0;
187	link_initialize(&node->fin_link);	190	link_initialize(&node->fin_link);
188	link_initialize(&node->ffn_link);	191	link_initialize(&node->ffn_link);
189	node->size = 0;	192	node->size = 0;
190	node->lnkcnt = 0;	193	node->lnkcnt = 0;
191	node->refcnt = 0;	194	node->refcnt = 0;
192	node->dirty = false;	195	node->dirty = false;
193	}	196	}
194		197
195	static uint16_t fat_bps_get(dev_handle_t dev_handle)	198	static uint16_t fat_bps_get(dev_handle_t dev_handle)
196	{	199	{
197	block_t *bb;	200	block_t *bb;
198	uint16_t bps;	201	uint16_t bps;
199		202
200	bb = block_get(dev_handle, BS_BLOCK);	203	bb = block_get(dev_handle, BS_BLOCK);
201	assert(bb != NULL);	204	assert(bb != NULL);
202	bps = uint16_t_le2host(FAT_BS(bb)->bps);	205	bps = uint16_t_le2host(FAT_BS(bb)->bps);
203	block_put(bb);	206	block_put(bb);
204		207
205	return bps;	208	return bps;
206	}	209	}
207		210
208	typedef enum {	211	typedef enum {
209	FAT_DENTRY_SKIP,	212	FAT_DENTRY_SKIP,
210	FAT_DENTRY_LAST,	213	FAT_DENTRY_LAST,
211	FAT_DENTRY_VALID	214	FAT_DENTRY_VALID
212	} fat_dentry_clsf_t;	215	} fat_dentry_clsf_t;
213		216
214	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)	217	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
215	{	218	{
216	if (d->attr & FAT_ATTR_VOLLABEL) {	219	if (d->attr & FAT_ATTR_VOLLABEL) {
217	/* volume label entry */	220	/* volume label entry */
218	return FAT_DENTRY_SKIP;	221	return FAT_DENTRY_SKIP;
219	}	222	}
220	if (d->name[0] == FAT_DENTRY_ERASED) {	223	if (d->name[0] == FAT_DENTRY_ERASED) {
221	/* not-currently-used entry */	224	/* not-currently-used entry */
222	return FAT_DENTRY_SKIP;	225	return FAT_DENTRY_SKIP;
223	}	226	}
224	if (d->name[0] == FAT_DENTRY_UNUSED) {	227	if (d->name[0] == FAT_DENTRY_UNUSED) {
225	/* never used entry */	228	/* never used entry */
226	return FAT_DENTRY_LAST;	229	return FAT_DENTRY_LAST;
227	}	230	}
228	if (d->name[0] == FAT_DENTRY_DOT) {	231	if (d->name[0] == FAT_DENTRY_DOT) {
229	/*	232	/*
230	* Most likely '.' or '..'.	233	* Most likely '.' or '..'.
231	* It cannot occur in a regular file name.	234	* It cannot occur in a regular file name.
232	*/	235	*/
233	return FAT_DENTRY_SKIP;	236	return FAT_DENTRY_SKIP;
234	}	237	}
235	return FAT_DENTRY_VALID;	238	return FAT_DENTRY_VALID;
236	}	239	}
237		240
238	static void fat_sync_node(fat_node_t *node)	241	static void fat_sync_node(fat_node_t *node)
239	{	242	{
240	/* TODO */	243	/* TODO */
241	}	244	}
242		245
243	/** Instantiate a FAT in-core node. */	246	/** Instantiate a FAT in-core node. */
244	static void *	-
245	fat_node_get(dev_handle_t dev_handle, fs_index_t index)	247	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
246	{	248	{
-		249	fat_idx_t *idx;
-		250	block_t *b;
-		251	fat_dentry_t *d;
-		252	fat_node_t *nodep;
-		253	unsigned bps;
-		254	unsigned dps;
-		255
-		256	idx = fat_idx_get_by_index(dev_handle, index);
-		257	if (!idx)
247	return NULL; /* TODO */	258	return NULL;
-		259
-		260	if (idx->nodep) {
-		261	/*
-		262	* We are lucky.
-		263	* The node is already instantiated in memory.
-		264	*/
-		265	idx->nodep->refcnt++;
-		266	return idx->nodep;
-		267	}
-		268
-		269	/*
-		270	* We must instantiate the node from the file system.
-		271	*/
-		272
-		273	assert(idx->pfc);
-		274
-		275	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
-		276	if (!nodep)
-		277	return NULL;
-		278	fat_node_initialize(nodep);
-		279
-		280	bps = fat_bps_get(dev_handle);
-		281	dps = bps / sizeof(fat_dentry_t);
-		282
-		283	b = _fat_block_get(dev_handle, idx->pfc,
-		284	(idx->pdi * sizeof(fat_dentry_t)) / bps);
-		285
-		286	assert(b);
-		287
-		288	d = ((fat_dentry_t *)b->data) + (idx->pdi % dps);
-		289	/* XXX */
248	}	290	}
249		291
250	static void fat_node_put(void *node)	292	static void fat_node_put(void *node)
251	{	293	{
252	/* TODO */	294	/* TODO */
253	}	295	}
254		296
255	static void *fat_create(int flags)	297	static void *fat_create(int flags)
256	{	298	{
257	return NULL; /* not supported at the moment */	299	return NULL; /* not supported at the moment */
258	}	300	}
259		301
260	static int fat_destroy(void *node)	302	static int fat_destroy(void *node)
261	{	303	{
262	return ENOTSUP; /* not supported at the moment */	304	return ENOTSUP; /* not supported at the moment */
263	}	305	}
264		306
265	static bool fat_link(void prnt, void chld, const char *name)	307	static bool fat_link(void prnt, void chld, const char *name)
266	{	308	{
267	return false; /* not supported at the moment */	309	return false; /* not supported at the moment */
268	}	310	}
269		311
270	static int fat_unlink(void prnt, void chld)	312	static int fat_unlink(void prnt, void chld)
271	{	313	{
272	return ENOTSUP; /* not supported at the moment */	314	return ENOTSUP; /* not supported at the moment */
273	}	315	}
274		316
275	static void fat_match(void prnt, const char *component)	317	static void fat_match(void prnt, const char *component)
276	{	318	{
277	fat_node_t parentp = (fat_node_t )prnt;	319	fat_node_t parentp = (fat_node_t )prnt;
278	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	320	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
279	unsigned i, j;	321	unsigned i, j;
280	unsigned bps; /* bytes per sector */	322	unsigned bps; /* bytes per sector */
281	unsigned dps; /* dentries per sector */	323	unsigned dps; /* dentries per sector */
282	unsigned blocks;	324	unsigned blocks;
283	fat_dentry_t *d;	325	fat_dentry_t *d;
284	block_t *b;	326	block_t *b;
285		327
286	bps = fat_bps_get(parentp->idx->dev_handle);	328	bps = fat_bps_get(parentp->idx->dev_handle);
287	dps = bps / sizeof(fat_dentry_t);	329	dps = bps / sizeof(fat_dentry_t);
288	blocks = parentp->size / bps + (parentp->size % bps != 0);	330	blocks = parentp->size / bps + (parentp->size % bps != 0);
289	for (i = 0; i < blocks; i++) {	331	for (i = 0; i < blocks; i++) {
290	unsigned dentries;	332	unsigned dentries;
291		333
292	b = fat_block_get(parentp, i);	334	b = fat_block_get(parentp, i);
293	dentries = (i == blocks - 1) ?	335	dentries = (i == blocks - 1) ?
294	parentp->size % sizeof(fat_dentry_t) :	336	parentp->size % sizeof(fat_dentry_t) :
295	dps;	337	dps;
296	for (j = 0; j < dentries; j++) {	338	for (j = 0; j < dentries; j++) {
297	d = ((fat_dentry_t *)b->data) + j;	339	d = ((fat_dentry_t *)b->data) + j;
298	switch (fat_classify_dentry(d)) {	340	switch (fat_classify_dentry(d)) {
299	case FAT_DENTRY_SKIP:	341	case FAT_DENTRY_SKIP:
300	continue;	342	continue;
301	case FAT_DENTRY_LAST:	343	case FAT_DENTRY_LAST:
302	block_put(b);	344	block_put(b);
303	return NULL;	345	return NULL;
304	default:	346	default:
305	case FAT_DENTRY_VALID:	347	case FAT_DENTRY_VALID:
306	dentry_name_canonify(d, name);	348	dentry_name_canonify(d, name);
307	break;	349	break;
308	}	350	}
309	if (strcmp(name, component) == 0) {	351	if (strcmp(name, component) == 0) {
310	/* hit */	352	/* hit */
311	fat_idx_t *idx = fat_idx_get_by_pos(	353	fat_idx_t *idx = fat_idx_get_by_pos(
312	parentp->idx->dev_handle, parentp->firstc,	354	parentp->idx->dev_handle, parentp->firstc,
313	i * dps + j);	355	i * dps + j);
314	if (!idx) {	356	if (!idx) {
315	/*	357	/*
316	* Can happen if memory is low or if we	358	* Can happen if memory is low or if we
317	* run out of 32-bit indices.	359	* run out of 32-bit indices.
318	*/	360	*/
319	block_put(b);	361	block_put(b);
320	return NULL;	362	return NULL;
321	}	363	}
322	void *node = fat_node_get(idx->dev_handle,	364	void *node = fat_node_get(idx->dev_handle,
323	idx->index);	365	idx->index);
324	block_put(b);	366	block_put(b);
325	return node;	367	return node;
326	}	368	}
327	}	369	}
328	block_put(b);	370	block_put(b);
329	}	371	}
330		372
331	return NULL;	373	return NULL;
332	}	374	}
333		375
334	static fs_index_t fat_index_get(void *node)	376	static fs_index_t fat_index_get(void *node)
335	{	377	{
336	fat_node_t fnodep = (fat_node_t )node;	378	fat_node_t fnodep = (fat_node_t )node;
337	if (!fnodep)	379	if (!fnodep)
338	return 0;	380	return 0;
339	return fnodep->idx->index;	381	return fnodep->idx->index;
340	}	382	}
341		383
342	static size_t fat_size_get(void *node)	384	static size_t fat_size_get(void *node)
343	{	385	{
344	return ((fat_node_t *)node)->size;	386	return ((fat_node_t *)node)->size;
345	}	387	}
346		388
347	static unsigned fat_lnkcnt_get(void *node)	389	static unsigned fat_lnkcnt_get(void *node)
348	{	390	{
349	return ((fat_node_t *)node)->lnkcnt;	391	return ((fat_node_t *)node)->lnkcnt;
350	}	392	}
351		393
352	static bool fat_has_children(void *node)	394	static bool fat_has_children(void *node)
353	{	395	{
354	fat_node_t nodep = (fat_node_t )node;	396	fat_node_t nodep = (fat_node_t )node;
355	unsigned bps;	397	unsigned bps;
356	unsigned dps;	398	unsigned dps;
357	unsigned blocks;	399	unsigned blocks;
358	block_t *b;	400	block_t *b;
359	unsigned i, j;	401	unsigned i, j;
360		402
361	if (nodep->type != FAT_DIRECTORY)	403	if (nodep->type != FAT_DIRECTORY)
362	return false;	404	return false;
363		405
364	bps = fat_bps_get(nodep->idx->dev_handle);	406	bps = fat_bps_get(nodep->idx->dev_handle);
365	dps = bps / sizeof(fat_dentry_t);	407	dps = bps / sizeof(fat_dentry_t);
366		408
367	blocks = nodep->size / bps + (nodep->size % bps != 0);	409	blocks = nodep->size / bps + (nodep->size % bps != 0);
368		410
369	for (i = 0; i < blocks; i++) {	411	for (i = 0; i < blocks; i++) {
370	unsigned dentries;	412	unsigned dentries;
371	fat_dentry_t *d;	413	fat_dentry_t *d;
372		414
373	b = fat_block_get(nodep, i);	415	b = fat_block_get(nodep, i);
374	dentries = (i == blocks - 1) ?	416	dentries = (i == blocks - 1) ?
375	nodep->size % sizeof(fat_dentry_t) :	417	nodep->size % sizeof(fat_dentry_t) :
376	dps;	418	dps;
377	for (j = 0; j < dentries; j++) {	419	for (j = 0; j < dentries; j++) {
378	d = ((fat_dentry_t *)b->data) + j;	420	d = ((fat_dentry_t *)b->data) + j;
379	switch (fat_classify_dentry(d)) {	421	switch (fat_classify_dentry(d)) {
380	case FAT_DENTRY_SKIP:	422	case FAT_DENTRY_SKIP:
381	continue;	423	continue;
382	case FAT_DENTRY_LAST:	424	case FAT_DENTRY_LAST:
383	block_put(b);	425	block_put(b);
384	return false;	426	return false;
385	default:	427	default:
386	case FAT_DENTRY_VALID:	428	case FAT_DENTRY_VALID:
387	block_put(b);	429	block_put(b);
388	return true;	430	return true;
389	}	431	}
390	block_put(b);	432	block_put(b);
391	return true;	433	return true;
392	}	434	}
393	block_put(b);	435	block_put(b);
394	}	436	}
395		437
396	return false;	438	return false;
397	}	439	}
398		440
399	static void *fat_root_get(dev_handle_t dev_handle)	441	static void *fat_root_get(dev_handle_t dev_handle)
400	{	442	{
401	return fat_node_get(dev_handle, FAT_CLST_RES1);	443	return fat_node_get(dev_handle, 0); /* TODO */
402	}	444	}
403		445
404	static char fat_plb_get_char(unsigned pos)	446	static char fat_plb_get_char(unsigned pos)
405	{	447	{
406	return fat_reg.plb_ro[pos % PLB_SIZE];	448	return fat_reg.plb_ro[pos % PLB_SIZE];
407	}	449	}
408		450
409	static bool fat_is_directory(void *node)	451	static bool fat_is_directory(void *node)
410	{	452	{
411	return ((fat_node_t *)node)->type == FAT_DIRECTORY;	453	return ((fat_node_t *)node)->type == FAT_DIRECTORY;
412	}	454	}
413		455
414	static bool fat_is_file(void *node)	456	static bool fat_is_file(void *node)
415	{	457	{
416	return ((fat_node_t *)node)->type == FAT_FILE;	458	return ((fat_node_t *)node)->type == FAT_FILE;
417	}	459	}
418		460
419	/** libfs operations */	461	/** libfs operations */
420	libfs_ops_t fat_libfs_ops = {	462	libfs_ops_t fat_libfs_ops = {
421	.match = fat_match,	463	.match = fat_match,
422	.node_get = fat_node_get,	464	.node_get = fat_node_get,
423	.node_put = fat_node_put,	465	.node_put = fat_node_put,
424	.create = fat_create,	466	.create = fat_create,
425	.destroy = fat_destroy,	467	.destroy = fat_destroy,
426	.link = fat_link,	468	.link = fat_link,
427	.unlink = fat_unlink,	469	.unlink = fat_unlink,
428	.index_get = fat_index_get,	470	.index_get = fat_index_get,
429	.size_get = fat_size_get,	471	.size_get = fat_size_get,
430	.lnkcnt_get = fat_lnkcnt_get,	472	.lnkcnt_get = fat_lnkcnt_get,
431	.has_children = fat_has_children,	473	.has_children = fat_has_children,
432	.root_get = fat_root_get,	474	.root_get = fat_root_get,
433	.plb_get_char = fat_plb_get_char,	475	.plb_get_char = fat_plb_get_char,
434	.is_directory = fat_is_directory,	476	.is_directory = fat_is_directory,
435	.is_file = fat_is_file	477	.is_file = fat_is_file
436	};	478	};
437		479
438	void fat_lookup(ipc_callid_t rid, ipc_call_t *request)	480	void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
439	{	481	{
440	libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);	482	libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
441	}	483	}
442		484
443	/**	485	/**
444	* @}	486	* @}
445	*/	487	*/
446		488

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 2890 → 2891