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
 
/** Futex protecting the list of cached free FAT nodes. */
static futex_t ffn_futex = FUTEX_INITIALIZER;
 
/** List of cached free FAT nodes. */
static LIST_INITIALIZE(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 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 firstc, 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 = firstc;
    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 (firstc == 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)
{
    futex_initialize(&node->lock, 1);
    node->idx = NULL;
    node->type = 0;
    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_node_sync(fat_node_t *node)
{
    /* TODO */
}
 
/** Internal version of fat_node_get().
 *
 * @param idxp      Locked index structure.
 */
static void *fat_node_get_core(fat_idx_t *idxp)
{
    block_t *b;
    fat_dentry_t *d;
    fat_node_t *nodep;
    unsigned bps;
    unsigned dps;
 
    if (idxp->nodep) {
        /*
         * We are lucky.
         * The node is already instantiated in memory.
         */
        futex_down(&idxp->nodep->lock);
        if (!idxp->nodep->refcnt++)
            list_remove(&nodep->ffn_link);
        futex_up(&idxp->nodep->lock);
        return idxp->nodep;
    }
 
    /*
     * We must instantiate the node from the file system.
     */
   
    assert(idxp->pfc);
 
    futex_down(&ffn_futex);
    if (!list_empty(&ffn_head)) {
        /* Try to use a cached free node structure. */
        fat_idx_t *idxp_tmp;
        nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
        if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
            goto skip_cache;
        idxp_tmp = nodep->idx;
        if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
            futex_up(&nodep->lock);
            goto skip_cache;
        }
        list_remove(&nodep->ffn_link);
        futex_up(&ffn_futex);
        if (nodep->dirty)
            fat_node_sync(nodep);
        idxp_tmp->nodep = NULL;
        futex_up(&nodep->lock);
        futex_up(&idxp_tmp->lock);
    } else {
skip_cache:
        /* Try to allocate a new node structure. */
        futex_up(&ffn_futex);
        nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
        if (!nodep)
            return NULL;
    }
    fat_node_initialize(nodep);
 
    bps = fat_bps_get(idxp->dev_handle);
    dps = bps / sizeof(fat_dentry_t);
 
    /* Read the block that contains the dentry of interest. */
    b = _fat_block_get(idxp->dev_handle, idxp->pfc,
        (idxp->pdi * sizeof(fat_dentry_t)) / bps);
    assert(b);
 
    d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
    if (d->attr & FAT_ATTR_SUBDIR) {
        /*
         * The only directory which does not have this bit set is the
         * root directory itself. The root directory node is handled
         * and initialized elsewhere.
         */
        nodep->type = FAT_DIRECTORY;
    } else {
        nodep->type = FAT_FILE;
    }
    nodep->firstc = uint16_t_le2host(d->firstc);
    nodep->size = uint32_t_le2host(d->size);
    nodep->lnkcnt = 1;
    nodep->refcnt = 1;
 
    block_put(b);
 
    /* Link the idx structure with the node structure. */
    nodep->idx = idxp;
    idxp->nodep = nodep;
 
    return nodep;
}
 
/** Instantiate a FAT in-core node. */
static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
{
    void *node;
    fat_idx_t *idxp;
 
    idxp = fat_idx_get_by_index(dev_handle, index);
    if (!idxp)
        return NULL;
    /* idxp->lock held */
    node = fat_node_get_core(idxp);
    futex_up(&idxp->lock);
    return node;
}
 
static void fat_node_put(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
 
    futex_down(&nodep->lock);
    if (!--nodep->refcnt) {
        futex_down(&ffn_futex);
        list_append(&nodep->ffn_link, &ffn_head);
        futex_up(&ffn_futex);
    }
    futex_up(&nodep->lock);
}
 
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;
 
    futex_down(&parentp->idx->lock);
    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);
                futex_up(&parentp->idx->lock);
                return NULL;
            default:
            case FAT_DENTRY_VALID:
                dentry_name_canonify(d, name);
                break;
            }
            if (strcmp(name, component) == 0) {
                /* hit */
                void *node;
                /*
                 * Assume tree hierarchy for locking.  We
                 * already have the parent and now we are going
                 * to lock the child.  Never lock in the oposite
                 * order.
                 */
                fat_idx_t *idx = fat_idx_get_by_pos(
                    parentp->idx->dev_handle, parentp->firstc,
                    i * dps + j);
                futex_up(&parentp->idx->lock);
                if (!idx) {
                    /*
                     * Can happen if memory is low or if we
                     * run out of 32-bit indices.
                     */
                    block_put(b);
                    return NULL;
                }
                node = fat_node_get_core(idx);
                futex_up(&idx->lock);
                block_put(b);
                return node;
            }
        }
        block_put(b);
    }
 
    futex_up(&parentp->idx->lock);
    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;
 
    futex_down(&nodep->idx->lock);
    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);
                futex_up(&nodep->idx->lock);
                return false;
            default:
            case FAT_DENTRY_VALID:
                block_put(b);
                futex_up(&nodep->idx->lock);
                return true;
            }
            block_put(b);
            futex_up(&nodep->idx->lock);
            return true;
        }
        block_put(b);
    }
 
    futex_up(&nodep->idx->lock);
    return false;
}
 
static void *fat_root_get(dev_handle_t dev_handle)
{
    return NULL;    /* 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 2951	Rev 2953
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	/** Futex protecting the list of cached free FAT nodes. */	53	/** Futex protecting the list of cached free FAT nodes. */
54	static futex_t ffn_futex = FUTEX_INITIALIZER;	54	static futex_t ffn_futex = FUTEX_INITIALIZER;
55		55
56	/** List of cached free FAT nodes. */	56	/** List of cached free FAT nodes. */
57	static LIST_INITIALIZE(ffn_head);	57	static LIST_INITIALIZE(ffn_head);
58		58
59	#define FAT_NAME_LEN 8	59	#define FAT_NAME_LEN 8
60	#define FAT_EXT_LEN 3	60	#define FAT_EXT_LEN 3
61		61
62	#define FAT_PAD ' '	62	#define FAT_PAD ' '
63		63
64	#define FAT_DENTRY_UNUSED 0x00	64	#define FAT_DENTRY_UNUSED 0x00
65	#define FAT_DENTRY_E5_ESC 0x05	65	#define FAT_DENTRY_E5_ESC 0x05
66	#define FAT_DENTRY_DOT 0x2e	66	#define FAT_DENTRY_DOT 0x2e
67	#define FAT_DENTRY_ERASED 0xe5	67	#define FAT_DENTRY_ERASED 0xe5
68		68
69	static void dentry_name_canonify(fat_dentry_t d, char buf)	69	static void dentry_name_canonify(fat_dentry_t d, char buf)
70	{	70	{
71	int i;	71	int i;
72		72
73	for (i = 0; i < FAT_NAME_LEN; i++) {	73	for (i = 0; i < FAT_NAME_LEN; i++) {
74	if (d->name[i] == FAT_PAD) {	74	if (d->name[i] == FAT_PAD) {
75	buf++;	75	buf++;
76	break;	76	break;
77	}	77	}
78	if (d->name[i] == FAT_DENTRY_E5_ESC)	78	if (d->name[i] == FAT_DENTRY_E5_ESC)
79	*buf++ = 0xe5;	79	*buf++ = 0xe5;
80	else	80	else
81	*buf++ = d->name[i];	81	*buf++ = d->name[i];
82	}	82	}
83	if (d->ext[0] != FAT_PAD)	83	if (d->ext[0] != FAT_PAD)
84	*buf++ = '.';	84	*buf++ = '.';
85	for (i = 0; i < FAT_EXT_LEN; i++) {	85	for (i = 0; i < FAT_EXT_LEN; i++) {
86	if (d->ext[i] == FAT_PAD) {	86	if (d->ext[i] == FAT_PAD) {
87	*buf = '\0';	87	*buf = '\0';
88	return;	88	return;
89	}	89	}
90	if (d->ext[i] == FAT_DENTRY_E5_ESC)	90	if (d->ext[i] == FAT_DENTRY_E5_ESC)
91	*buf++ = 0xe5;	91	*buf++ = 0xe5;
92	else	92	else
93	*buf++ = d->ext[i];	93	*buf++ = d->ext[i];
94	}	94	}
95	}	95	}
96		96
97	/* TODO move somewhere else */	97	/* TODO move somewhere else */
98	typedef struct {	98	typedef struct {
99	void *data;	99	void *data;
100	} block_t;	100	} block_t;
101		101
102	static block_t *block_get(dev_handle_t dev_handle, off_t offset)	102	static block_t *block_get(dev_handle_t dev_handle, off_t offset)
103	{	103	{
104	return NULL; /* TODO */	104	return NULL; /* TODO */
105	}	105	}
106		106
107	static void block_put(block_t *block)	107	static void block_put(block_t *block)
108	{	108	{
109	/* TODO */	109	/* TODO */
110	}	110	}
111		111
112	#define FAT_BS(b) ((fat_bs_t *)((b)->data))	112	#define FAT_BS(b) ((fat_bs_t *)((b)->data))
113		113
114	#define FAT_CLST_RES0 0x0000	114	#define FAT_CLST_RES0 0x0000
115	#define FAT_CLST_RES1 0x0001 /* internally used to mark root directory */	115	#define FAT_CLST_RES1 0x0001 /* internally used to mark root directory */
116	#define FAT_CLST_FIRST 0x0002	116	#define FAT_CLST_FIRST 0x0002
117	#define FAT_CLST_BAD 0xfff7	117	#define FAT_CLST_BAD 0xfff7
118	#define FAT_CLST_LAST1 0xfff8	118	#define FAT_CLST_LAST1 0xfff8
119	#define FAT_CLST_LAST8 0xffff	119	#define FAT_CLST_LAST8 0xffff
120		120
121	#define fat_block_get(np, off) \	121	#define fat_block_get(np, off) \
122	_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))	122	_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))
123		123
124	static block_t *	124	static block_t *
125	_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)	125	_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)
126	{	126	{
127	block_t *bb;	127	block_t *bb;
128	block_t *b;	128	block_t *b;
129	unsigned bps;	129	unsigned bps;
130	unsigned spc;	130	unsigned spc;
131	unsigned rscnt; /* block address of the first FAT */	131	unsigned rscnt; /* block address of the first FAT */
132	unsigned fatcnt;	132	unsigned fatcnt;
133	unsigned rde;	133	unsigned rde;
134	unsigned rds; /* root directory size */	134	unsigned rds; /* root directory size */
135	unsigned sf;	135	unsigned sf;
136	unsigned ssa; /* size of the system area */	136	unsigned ssa; /* size of the system area */
137	unsigned clusters;	137	unsigned clusters;
138	fat_cluster_t clst = firstc;	138	fat_cluster_t clst = firstc;
139	unsigned i;	139	unsigned i;
140		140
141	bb = block_get(dev_handle, BS_BLOCK);	141	bb = block_get(dev_handle, BS_BLOCK);
142	bps = uint16_t_le2host(FAT_BS(bb)->bps);	142	bps = uint16_t_le2host(FAT_BS(bb)->bps);
143	spc = FAT_BS(bb)->spc;	143	spc = FAT_BS(bb)->spc;
144	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);	144	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
145	fatcnt = FAT_BS(bb)->fatcnt;	145	fatcnt = FAT_BS(bb)->fatcnt;
146	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);	146	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
147	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);	147	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
148	block_put(bb);	148	block_put(bb);
149		149
150	rds = (sizeof(fat_dentry_t) * rde) / bps;	150	rds = (sizeof(fat_dentry_t) * rde) / bps;
151	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);	151	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
152	ssa = rscnt + fatcnt * sf + rds;	152	ssa = rscnt + fatcnt * sf + rds;
153		153
154	if (firstc == FAT_CLST_RES1) {	154	if (firstc == FAT_CLST_RES1) {
155	/* root directory special case */	155	/* root directory special case */
156	assert(offset < rds);	156	assert(offset < rds);
157	b = block_get(dev_handle, rscnt + fatcnt * sf + offset);	157	b = block_get(dev_handle, rscnt + fatcnt * sf + offset);
158	return b;	158	return b;
159	}	159	}
160		160
161	clusters = offset / spc;	161	clusters = offset / spc;
162	for (i = 0; i < clusters; i++) {	162	for (i = 0; i < clusters; i++) {
163	unsigned fsec; /* sector offset relative to FAT1 */	163	unsigned fsec; /* sector offset relative to FAT1 */
164	unsigned fidx; /* FAT1 entry index */	164	unsigned fidx; /* FAT1 entry index */
165		165
166	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);	166	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
167	fsec = (clst * sizeof(fat_cluster_t)) / bps;	167	fsec = (clst * sizeof(fat_cluster_t)) / bps;
168	fidx = clst % (bps / sizeof(fat_cluster_t));	168	fidx = clst % (bps / sizeof(fat_cluster_t));
169	/* read FAT1 */	169	/* read FAT1 */
170	b = block_get(dev_handle, rscnt + fsec);	170	b = block_get(dev_handle, rscnt + fsec);
171	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);	171	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
172	assert(clst != FAT_CLST_BAD);	172	assert(clst != FAT_CLST_BAD);
173	assert(clst < FAT_CLST_LAST1);	173	assert(clst < FAT_CLST_LAST1);
174	block_put(b);	174	block_put(b);
175	}	175	}
176		176
177	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +	177	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
178	offset % spc);	178	offset % spc);
179		179
180	return b;	180	return b;
181	}	181	}
182		182
183	static void fat_node_initialize(fat_node_t *node)	183	static void fat_node_initialize(fat_node_t *node)
184	{	184	{
185	futex_initialize(&node->lock, 1);	185	futex_initialize(&node->lock, 1);
186	node->idx = NULL;	186	node->idx = NULL;
187	node->type = 0;	187	node->type = 0;
188	link_initialize(&node->ffn_link);	188	link_initialize(&node->ffn_link);
189	node->size = 0;	189	node->size = 0;
190	node->lnkcnt = 0;	190	node->lnkcnt = 0;
191	node->refcnt = 0;	191	node->refcnt = 0;
192	node->dirty = false;	192	node->dirty = false;
193	}	193	}
194		194
195	static uint16_t fat_bps_get(dev_handle_t dev_handle)	195	static uint16_t fat_bps_get(dev_handle_t dev_handle)
196	{	196	{
197	block_t *bb;	197	block_t *bb;
198	uint16_t bps;	198	uint16_t bps;
199		199
200	bb = block_get(dev_handle, BS_BLOCK);	200	bb = block_get(dev_handle, BS_BLOCK);
201	assert(bb != NULL);	201	assert(bb != NULL);
202	bps = uint16_t_le2host(FAT_BS(bb)->bps);	202	bps = uint16_t_le2host(FAT_BS(bb)->bps);
203	block_put(bb);	203	block_put(bb);
204		204
205	return bps;	205	return bps;
206	}	206	}
207		207
208	typedef enum {	208	typedef enum {
209	FAT_DENTRY_SKIP,	209	FAT_DENTRY_SKIP,
210	FAT_DENTRY_LAST,	210	FAT_DENTRY_LAST,
211	FAT_DENTRY_VALID	211	FAT_DENTRY_VALID
212	} fat_dentry_clsf_t;	212	} fat_dentry_clsf_t;
213		213
214	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)	214	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
215	{	215	{
216	if (d->attr & FAT_ATTR_VOLLABEL) {	216	if (d->attr & FAT_ATTR_VOLLABEL) {
217	/* volume label entry */	217	/* volume label entry */
218	return FAT_DENTRY_SKIP;	218	return FAT_DENTRY_SKIP;
219	}	219	}
220	if (d->name[0] == FAT_DENTRY_ERASED) {	220	if (d->name[0] == FAT_DENTRY_ERASED) {
221	/* not-currently-used entry */	221	/* not-currently-used entry */
222	return FAT_DENTRY_SKIP;	222	return FAT_DENTRY_SKIP;
223	}	223	}
224	if (d->name[0] == FAT_DENTRY_UNUSED) {	224	if (d->name[0] == FAT_DENTRY_UNUSED) {
225	/* never used entry */	225	/* never used entry */
226	return FAT_DENTRY_LAST;	226	return FAT_DENTRY_LAST;
227	}	227	}
228	if (d->name[0] == FAT_DENTRY_DOT) {	228	if (d->name[0] == FAT_DENTRY_DOT) {
229	/*	229	/*
230	* Most likely '.' or '..'.	230	* Most likely '.' or '..'.
231	* It cannot occur in a regular file name.	231	* It cannot occur in a regular file name.
232	*/	232	*/
233	return FAT_DENTRY_SKIP;	233	return FAT_DENTRY_SKIP;
234	}	234	}
235	return FAT_DENTRY_VALID;	235	return FAT_DENTRY_VALID;
236	}	236	}
237		237
238	static void fat_node_sync(fat_node_t *node)	238	static void fat_node_sync(fat_node_t *node)
239	{	239	{
240	/* TODO */	240	/* TODO */
241	}	241	}
242		242
243	/** Internal version of fat_node_get().	243	/** Internal version of fat_node_get().
244	*	244	*
245	* @param idxp Locked index structure.	245	* @param idxp Locked index structure.
246	*/	246	*/
247	static void fat_node_get_core(fat_idx_t idxp)	247	static void fat_node_get_core(fat_idx_t idxp)
248	{	248	{
249	block_t *b;	249	block_t *b;
250	fat_dentry_t *d;	250	fat_dentry_t *d;
251	fat_node_t *nodep;	251	fat_node_t *nodep;
252	unsigned bps;	252	unsigned bps;
253	unsigned dps;	253	unsigned dps;
254		254
255	if (idxp->nodep) {	255	if (idxp->nodep) {
256	/*	256	/*
257	* We are lucky.	257	* We are lucky.
258	* The node is already instantiated in memory.	258	* The node is already instantiated in memory.
259	*/	259	*/
260	futex_down(&idxp->nodep->lock);	260	futex_down(&idxp->nodep->lock);
261	if (!idxp->nodep->refcnt++)	261	if (!idxp->nodep->refcnt++)
262	list_remove(&nodep->ffn_link);	262	list_remove(&nodep->ffn_link);
263	futex_up(&idxp->nodep->lock);	263	futex_up(&idxp->nodep->lock);
264	return idxp->nodep;	264	return idxp->nodep;
265	}	265	}
266		266
267	/*	267	/*
268	* We must instantiate the node from the file system.	268	* We must instantiate the node from the file system.
269	*/	269	*/
270		270
271	assert(idxp->pfc);	271	assert(idxp->pfc);
272		272
273	futex_down(&ffn_futex);	273	futex_down(&ffn_futex);
274	if (!list_empty(&ffn_head)) {	274	if (!list_empty(&ffn_head)) {
275	/* Try to use a cached free node structure. */	275	/* Try to use a cached free node structure. */
276	fat_idx_t *idxp_tmp;	276	fat_idx_t *idxp_tmp;
277	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);	277	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
278	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)	278	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
279	goto skip_cache;	279	goto skip_cache;
280	idxp_tmp = nodep->idx;	280	idxp_tmp = nodep->idx;
281	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {	281	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
282	futex_up(&nodep->lock);	282	futex_up(&nodep->lock);
283	goto skip_cache;	283	goto skip_cache;
284	}	284	}
285	list_remove(&nodep->ffn_link);	285	list_remove(&nodep->ffn_link);
286	futex_up(&ffn_futex);	286	futex_up(&ffn_futex);
287	if (nodep->dirty)	287	if (nodep->dirty)
288	fat_node_sync(nodep);	288	fat_node_sync(nodep);
289	idxp_tmp->nodep = NULL;	289	idxp_tmp->nodep = NULL;
290	futex_up(&nodep->lock);	290	futex_up(&nodep->lock);
291	futex_up(&idxp_tmp->lock);	291	futex_up(&idxp_tmp->lock);
292	} else {	292	} else {
293	skip_cache:	293	skip_cache:
294	/* Try to allocate a new node structure. */	294	/* Try to allocate a new node structure. */
295	futex_up(&ffn_futex);	295	futex_up(&ffn_futex);
296	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));	296	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
297	if (!nodep)	297	if (!nodep)
298	return NULL;	298	return NULL;
299	}	299	}
300	fat_node_initialize(nodep);	300	fat_node_initialize(nodep);
301		301
302	bps = fat_bps_get(idxp->dev_handle);	302	bps = fat_bps_get(idxp->dev_handle);
303	dps = bps / sizeof(fat_dentry_t);	303	dps = bps / sizeof(fat_dentry_t);
304		304
305	/* Read the block that contains the dentry of interest. */	305	/* Read the block that contains the dentry of interest. */
306	b = _fat_block_get(idxp->dev_handle, idxp->pfc,	306	b = _fat_block_get(idxp->dev_handle, idxp->pfc,
307	(idxp->pdi * sizeof(fat_dentry_t)) / bps);	307	(idxp->pdi * sizeof(fat_dentry_t)) / bps);
308	assert(b);	308	assert(b);
309		309
310	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);	310	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
311	if (d->attr & FAT_ATTR_SUBDIR) {	311	if (d->attr & FAT_ATTR_SUBDIR) {
312	/*	312	/*
313	* The only directory which does not have this bit set is the	313	* The only directory which does not have this bit set is the
314	* root directory itself. The root directory node is handled	314	* root directory itself. The root directory node is handled
315	* and initialized elsewhere.	315	* and initialized elsewhere.
316	*/	316	*/
317	nodep->type = FAT_DIRECTORY;	317	nodep->type = FAT_DIRECTORY;
318	} else {	318	} else {
319	nodep->type = FAT_FILE;	319	nodep->type = FAT_FILE;
320	}	320	}
321	nodep->firstc = uint16_t_le2host(d->firstc);	321	nodep->firstc = uint16_t_le2host(d->firstc);
322	nodep->size = uint32_t_le2host(d->size);	322	nodep->size = uint32_t_le2host(d->size);
323	nodep->lnkcnt = 1;	323	nodep->lnkcnt = 1;
324	nodep->refcnt = 1;	324	nodep->refcnt = 1;
325		325
326	block_put(b);	326	block_put(b);
327		327
328	/* Link the idx structure with the node structure. */	328	/* Link the idx structure with the node structure. */
329	nodep->idx = idxp;	329	nodep->idx = idxp;
330	idxp->nodep = nodep;	330	idxp->nodep = nodep;
331		331
332	return nodep;	332	return nodep;
333	}	333	}
334		334
335	/** Instantiate a FAT in-core node. */	335	/** Instantiate a FAT in-core node. */
336	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)	336	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
337	{	337	{
338	void *node;	338	void *node;
339	fat_idx_t *idxp;	339	fat_idx_t *idxp;
340		340
341	idxp = fat_idx_get_by_index(dev_handle, index);	341	idxp = fat_idx_get_by_index(dev_handle, index);
342	if (!idxp)	342	if (!idxp)
343	return NULL;	343	return NULL;
344	/* idxp->lock held */	344	/* idxp->lock held */
345	node = fat_node_get_core(idxp);	345	node = fat_node_get_core(idxp);
346	futex_up(&idxp->lock);	346	futex_up(&idxp->lock);
347	return node;	347	return node;
348	}	348	}
349		349
350	static void fat_node_put(void *node)	350	static void fat_node_put(void *node)
351	{	351	{
352	fat_node_t nodep = (fat_node_t )node;	352	fat_node_t nodep = (fat_node_t )node;
353		353
354	futex_down(&nodep->lock);	354	futex_down(&nodep->lock);
355	if (!--nodep->refcnt) {	355	if (!--nodep->refcnt) {
356	futex_down(&ffn_futex);	356	futex_down(&ffn_futex);
357	list_append(&nodep->ffn_link, &ffn_head);	357	list_append(&nodep->ffn_link, &ffn_head);
358	futex_up(&ffn_futex);	358	futex_up(&ffn_futex);
359	}	359	}
360	futex_up(&nodep->lock);	360	futex_up(&nodep->lock);
361	}	361	}
362		362
363	static void *fat_create(int flags)	363	static void *fat_create(int flags)
364	{	364	{
365	return NULL; /* not supported at the moment */	365	return NULL; /* not supported at the moment */
366	}	366	}
367		367
368	static int fat_destroy(void *node)	368	static int fat_destroy(void *node)
369	{	369	{
370	return ENOTSUP; /* not supported at the moment */	370	return ENOTSUP; /* not supported at the moment */
371	}	371	}
372		372
373	static bool fat_link(void prnt, void chld, const char *name)	373	static bool fat_link(void prnt, void chld, const char *name)
374	{	374	{
375	return false; /* not supported at the moment */	375	return false; /* not supported at the moment */
376	}	376	}
377		377
378	static int fat_unlink(void prnt, void chld)	378	static int fat_unlink(void prnt, void chld)
379	{	379	{
380	return ENOTSUP; /* not supported at the moment */	380	return ENOTSUP; /* not supported at the moment */
381	}	381	}
382		382
383	static void fat_match(void prnt, const char *component)	383	static void fat_match(void prnt, const char *component)
384	{	384	{
385	fat_node_t parentp = (fat_node_t )prnt;	385	fat_node_t parentp = (fat_node_t )prnt;
386	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	386	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
387	unsigned i, j;	387	unsigned i, j;
388	unsigned bps; /* bytes per sector */	388	unsigned bps; /* bytes per sector */
389	unsigned dps; /* dentries per sector */	389	unsigned dps; /* dentries per sector */
390	unsigned blocks;	390	unsigned blocks;
391	fat_dentry_t *d;	391	fat_dentry_t *d;
392	block_t *b;	392	block_t *b;
393		393
-		394	futex_down(&parentp->idx->lock);
394	bps = fat_bps_get(parentp->idx->dev_handle);	395	bps = fat_bps_get(parentp->idx->dev_handle);
395	dps = bps / sizeof(fat_dentry_t);	396	dps = bps / sizeof(fat_dentry_t);
396	blocks = parentp->size / bps + (parentp->size % bps != 0);	397	blocks = parentp->size / bps + (parentp->size % bps != 0);
397	for (i = 0; i < blocks; i++) {	398	for (i = 0; i < blocks; i++) {
398	unsigned dentries;	399	unsigned dentries;
399		400
400	b = fat_block_get(parentp, i);	401	b = fat_block_get(parentp, i);
401	dentries = (i == blocks - 1) ?	402	dentries = (i == blocks - 1) ?
402	parentp->size % sizeof(fat_dentry_t) :	403	parentp->size % sizeof(fat_dentry_t) :
403	dps;	404	dps;
404	for (j = 0; j < dentries; j++) {	405	for (j = 0; j < dentries; j++) {
405	d = ((fat_dentry_t *)b->data) + j;	406	d = ((fat_dentry_t *)b->data) + j;
406	switch (fat_classify_dentry(d)) {	407	switch (fat_classify_dentry(d)) {
407	case FAT_DENTRY_SKIP:	408	case FAT_DENTRY_SKIP:
408	continue;	409	continue;
409	case FAT_DENTRY_LAST:	410	case FAT_DENTRY_LAST:
410	block_put(b);	411	block_put(b);
-		412	futex_up(&parentp->idx->lock);
411	return NULL;	413	return NULL;
412	default:	414	default:
413	case FAT_DENTRY_VALID:	415	case FAT_DENTRY_VALID:
414	dentry_name_canonify(d, name);	416	dentry_name_canonify(d, name);
415	break;	417	break;
416	}	418	}
417	if (strcmp(name, component) == 0) {	419	if (strcmp(name, component) == 0) {
418	/* hit */	420	/* hit */
419	void *node;	421	void *node;
-		422	/*
-		423	* Assume tree hierarchy for locking. We
-		424	* already have the parent and now we are going
-		425	* to lock the child. Never lock in the oposite
-		426	* order.
-		427	*/
420	fat_idx_t *idx = fat_idx_get_by_pos(	428	fat_idx_t *idx = fat_idx_get_by_pos(
421	parentp->idx->dev_handle, parentp->firstc,	429	parentp->idx->dev_handle, parentp->firstc,
422	i * dps + j);	430	i * dps + j);
-		431	futex_up(&parentp->idx->lock);
423	if (!idx) {	432	if (!idx) {
424	/*	433	/*
425	* Can happen if memory is low or if we	434	* Can happen if memory is low or if we
426	* run out of 32-bit indices.	435	* run out of 32-bit indices.
427	*/	436	*/
428	block_put(b);	437	block_put(b);
429	return NULL;	438	return NULL;
430	}	439	}
431	node = fat_node_get_core(idx);	440	node = fat_node_get_core(idx);
432	futex_up(&idx->lock);	441	futex_up(&idx->lock);
433	block_put(b);	442	block_put(b);
434	return node;	443	return node;
435	}	444	}
436	}	445	}
437	block_put(b);	446	block_put(b);
438	}	447	}
439		-
-		448	futex_up(&parentp->idx->lock);
440	return NULL;	449	return NULL;
441	}	450	}
442		451
443	static fs_index_t fat_index_get(void *node)	452	static fs_index_t fat_index_get(void *node)
444	{	453	{
445	fat_node_t fnodep = (fat_node_t )node;	454	fat_node_t fnodep = (fat_node_t )node;
446	if (!fnodep)	455	if (!fnodep)
447	return 0;	456	return 0;
448	return fnodep->idx->index;	457	return fnodep->idx->index;
449	}	458	}
450		459
451	static size_t fat_size_get(void *node)	460	static size_t fat_size_get(void *node)
452	{	461	{
453	return ((fat_node_t *)node)->size;	462	return ((fat_node_t *)node)->size;
454	}	463	}
455		464
456	static unsigned fat_lnkcnt_get(void *node)	465	static unsigned fat_lnkcnt_get(void *node)
457	{	466	{
458	return ((fat_node_t *)node)->lnkcnt;	467	return ((fat_node_t *)node)->lnkcnt;
459	}	468	}
460		469
461	static bool fat_has_children(void *node)	470	static bool fat_has_children(void *node)
462	{	471	{
463	fat_node_t nodep = (fat_node_t )node;	472	fat_node_t nodep = (fat_node_t )node;
464	unsigned bps;	473	unsigned bps;
465	unsigned dps;	474	unsigned dps;
466	unsigned blocks;	475	unsigned blocks;
467	block_t *b;	476	block_t *b;
468	unsigned i, j;	477	unsigned i, j;
469		478
470	if (nodep->type != FAT_DIRECTORY)	479	if (nodep->type != FAT_DIRECTORY)
471	return false;	480	return false;
472		481
473	futex_down(&nodep->idx->lock);	482	futex_down(&nodep->idx->lock);
474	bps = fat_bps_get(nodep->idx->dev_handle);	483	bps = fat_bps_get(nodep->idx->dev_handle);
475	dps = bps / sizeof(fat_dentry_t);	484	dps = bps / sizeof(fat_dentry_t);
476		485
477	blocks = nodep->size / bps + (nodep->size % bps != 0);	486	blocks = nodep->size / bps + (nodep->size % bps != 0);
478		487
479	for (i = 0; i < blocks; i++) {	488	for (i = 0; i < blocks; i++) {
480	unsigned dentries;	489	unsigned dentries;
481	fat_dentry_t *d;	490	fat_dentry_t *d;
482		491
483	b = fat_block_get(nodep, i);	492	b = fat_block_get(nodep, i);
484	dentries = (i == blocks - 1) ?	493	dentries = (i == blocks - 1) ?
485	nodep->size % sizeof(fat_dentry_t) :	494	nodep->size % sizeof(fat_dentry_t) :
486	dps;	495	dps;
487	for (j = 0; j < dentries; j++) {	496	for (j = 0; j < dentries; j++) {
488	d = ((fat_dentry_t *)b->data) + j;	497	d = ((fat_dentry_t *)b->data) + j;
489	switch (fat_classify_dentry(d)) {	498	switch (fat_classify_dentry(d)) {
490	case FAT_DENTRY_SKIP:	499	case FAT_DENTRY_SKIP:

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 2951 → 2953