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 BS_SIZE         512
 
/** 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, size_t bs)
{
    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
#define FAT_CLST_FIRST  0x0002
#define FAT_CLST_BAD    0xfff7
#define FAT_CLST_LAST1  0xfff8
#define FAT_CLST_LAST8  0xffff
 
/* internally used to mark root directory's parent */
#define FAT_CLST_ROOTPAR    FAT_CLST_RES0
/* internally used to mark root directory */
#define FAT_CLST_ROOT       FAT_CLST_RES1
 
#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, BS_SIZE);
    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_ROOT) {
        /* root directory special case */
        assert(offset < rds);
        b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
        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, bps);
        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, bps);
 
    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, BS_SIZE);
    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 fat_node_get(dev_handle, 0);
}
 
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_mounted(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
    block_t *bb;
    uint16_t rde;
    int rc;
 
    /* Read the number of root directory entries. */
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
    block_put(bb);
 
    rc = fat_idx_init_by_dev_handle(dev_handle);
    if (rc != EOK) {
        ipc_answer_0(rid, rc);
        return;
    }
 
    /* Initialize the root node. */
    fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t));
    if (!rootp) {
        fat_idx_fini_by_dev_handle(dev_handle);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    fat_node_initialize(rootp);
 
    fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0);
    if (!ridxp) {
        free(rootp);
        fat_idx_fini_by_dev_handle(dev_handle);
        ipc_answer_0(rid, ENOMEM);
        return;
    }
    assert(ridxp->index == 0);
    /* ridxp->lock held */
 
    rootp->type = FAT_DIRECTORY;
    rootp->firstc = FAT_CLST_ROOT;
    rootp->refcnt = 1;
    rootp->size = rde * sizeof(fat_dentry_t);
    rootp->idx = ridxp;
    ridxp->nodep = rootp;
   
    futex_up(&ridxp->lock);
 
    ipc_answer_0(rid, EOK);
}
 
void fat_mount(ipc_callid_t rid, ipc_call_t *request)
{
    ipc_answer_0(rid, ENOTSUP);
}
 
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
}
 
/**
 * @}
 */
 

Rev 3119	Rev 3253
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	#define BS_SIZE 512
52		53
53	/** Futex protecting the list of cached free FAT nodes. */	54	/** Futex protecting the list of cached free FAT nodes. */
54	static futex_t ffn_futex = FUTEX_INITIALIZER;	55	static futex_t ffn_futex = FUTEX_INITIALIZER;
55		56
56	/** List of cached free FAT nodes. */	57	/** List of cached free FAT nodes. */
57	static LIST_INITIALIZE(ffn_head);	58	static LIST_INITIALIZE(ffn_head);
58		59
59	#define FAT_NAME_LEN 8	60	#define FAT_NAME_LEN 8
60	#define FAT_EXT_LEN 3	61	#define FAT_EXT_LEN 3
61		62
62	#define FAT_PAD ' '	63	#define FAT_PAD ' '
63		64
64	#define FAT_DENTRY_UNUSED 0x00	65	#define FAT_DENTRY_UNUSED 0x00
65	#define FAT_DENTRY_E5_ESC 0x05	66	#define FAT_DENTRY_E5_ESC 0x05
66	#define FAT_DENTRY_DOT 0x2e	67	#define FAT_DENTRY_DOT 0x2e
67	#define FAT_DENTRY_ERASED 0xe5	68	#define FAT_DENTRY_ERASED 0xe5
68		69
69	static void dentry_name_canonify(fat_dentry_t d, char buf)	70	static void dentry_name_canonify(fat_dentry_t d, char buf)
70	{	71	{
71	int i;	72	int i;
72		73
73	for (i = 0; i < FAT_NAME_LEN; i++) {	74	for (i = 0; i < FAT_NAME_LEN; i++) {
74	if (d->name[i] == FAT_PAD) {	75	if (d->name[i] == FAT_PAD) {
75	buf++;	76	buf++;
76	break;	77	break;
77	}	78	}
78	if (d->name[i] == FAT_DENTRY_E5_ESC)	79	if (d->name[i] == FAT_DENTRY_E5_ESC)
79	*buf++ = 0xe5;	80	*buf++ = 0xe5;
80	else	81	else
81	*buf++ = d->name[i];	82	*buf++ = d->name[i];
82	}	83	}
83	if (d->ext[0] != FAT_PAD)	84	if (d->ext[0] != FAT_PAD)
84	*buf++ = '.';	85	*buf++ = '.';
85	for (i = 0; i < FAT_EXT_LEN; i++) {	86	for (i = 0; i < FAT_EXT_LEN; i++) {
86	if (d->ext[i] == FAT_PAD) {	87	if (d->ext[i] == FAT_PAD) {
87	*buf = '\0';	88	*buf = '\0';
88	return;	89	return;
89	}	90	}
90	if (d->ext[i] == FAT_DENTRY_E5_ESC)	91	if (d->ext[i] == FAT_DENTRY_E5_ESC)
91	*buf++ = 0xe5;	92	*buf++ = 0xe5;
92	else	93	else
93	*buf++ = d->ext[i];	94	*buf++ = d->ext[i];
94	}	95	}
95	}	96	}
96		97
97	/* TODO move somewhere else */	98	/* TODO move somewhere else */
98	typedef struct {	99	typedef struct {
99	void *data;	100	void *data;
100	} block_t;	101	} block_t;
101		102
102	static block_t *block_get(dev_handle_t dev_handle, off_t offset)	103	static block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
103	{	104	{
104	return NULL; /* TODO */	105	return NULL; /* TODO */
105	}	106	}
106		107
107	static void block_put(block_t *block)	108	static void block_put(block_t *block)
108	{	109	{
109	/* TODO */	110	/* TODO */
110	}	111	}
111		112
112	#define FAT_BS(b) ((fat_bs_t *)((b)->data))	113	#define FAT_BS(b) ((fat_bs_t *)((b)->data))
113		114
114	#define FAT_CLST_RES0 0x0000	115	#define FAT_CLST_RES0 0x0000
115	#define FAT_CLST_RES1 0x0001	116	#define FAT_CLST_RES1 0x0001
116	#define FAT_CLST_FIRST 0x0002	117	#define FAT_CLST_FIRST 0x0002
117	#define FAT_CLST_BAD 0xfff7	118	#define FAT_CLST_BAD 0xfff7
118	#define FAT_CLST_LAST1 0xfff8	119	#define FAT_CLST_LAST1 0xfff8
119	#define FAT_CLST_LAST8 0xffff	120	#define FAT_CLST_LAST8 0xffff
120		121
121	/* internally used to mark root directory's parent */	122	/* internally used to mark root directory's parent */
122	#define FAT_CLST_ROOTPAR FAT_CLST_RES0	123	#define FAT_CLST_ROOTPAR FAT_CLST_RES0
123	/* internally used to mark root directory */	124	/* internally used to mark root directory */
124	#define FAT_CLST_ROOT FAT_CLST_RES1	125	#define FAT_CLST_ROOT FAT_CLST_RES1
125		126
126	#define fat_block_get(np, off) \	127	#define fat_block_get(np, off) \
127	_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))	128	_fat_block_get((np)->idx->dev_handle, (np)->firstc, (off))
128		129
129	static block_t *	130	static block_t *
130	_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)	131	_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)
131	{	132	{
132	block_t *bb;	133	block_t *bb;
133	block_t *b;	134	block_t *b;
134	unsigned bps;	135	unsigned bps;
135	unsigned spc;	136	unsigned spc;
136	unsigned rscnt; /* block address of the first FAT */	137	unsigned rscnt; /* block address of the first FAT */
137	unsigned fatcnt;	138	unsigned fatcnt;
138	unsigned rde;	139	unsigned rde;
139	unsigned rds; /* root directory size */	140	unsigned rds; /* root directory size */
140	unsigned sf;	141	unsigned sf;
141	unsigned ssa; /* size of the system area */	142	unsigned ssa; /* size of the system area */
142	unsigned clusters;	143	unsigned clusters;
143	fat_cluster_t clst = firstc;	144	fat_cluster_t clst = firstc;
144	unsigned i;	145	unsigned i;
145		146
146	bb = block_get(dev_handle, BS_BLOCK);	147	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
147	bps = uint16_t_le2host(FAT_BS(bb)->bps);	148	bps = uint16_t_le2host(FAT_BS(bb)->bps);
148	spc = FAT_BS(bb)->spc;	149	spc = FAT_BS(bb)->spc;
149	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);	150	rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
150	fatcnt = FAT_BS(bb)->fatcnt;	151	fatcnt = FAT_BS(bb)->fatcnt;
151	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);	152	rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
152	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);	153	sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
153	block_put(bb);	154	block_put(bb);
154		155
155	rds = (sizeof(fat_dentry_t) * rde) / bps;	156	rds = (sizeof(fat_dentry_t) * rde) / bps;
156	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);	157	rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
157	ssa = rscnt + fatcnt * sf + rds;	158	ssa = rscnt + fatcnt * sf + rds;
158		159
159	if (firstc == FAT_CLST_ROOT) {	160	if (firstc == FAT_CLST_ROOT) {
160	/* root directory special case */	161	/* root directory special case */
161	assert(offset < rds);	162	assert(offset < rds);
162	b = block_get(dev_handle, rscnt + fatcnt * sf + offset);	163	b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
163	return b;	164	return b;
164	}	165	}
165		166
166	clusters = offset / spc;	167	clusters = offset / spc;
167	for (i = 0; i < clusters; i++) {	168	for (i = 0; i < clusters; i++) {
168	unsigned fsec; /* sector offset relative to FAT1 */	169	unsigned fsec; /* sector offset relative to FAT1 */
169	unsigned fidx; /* FAT1 entry index */	170	unsigned fidx; /* FAT1 entry index */
170		171
171	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);	172	assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
172	fsec = (clst * sizeof(fat_cluster_t)) / bps;	173	fsec = (clst * sizeof(fat_cluster_t)) / bps;
173	fidx = clst % (bps / sizeof(fat_cluster_t));	174	fidx = clst % (bps / sizeof(fat_cluster_t));
174	/* read FAT1 */	175	/* read FAT1 */
175	b = block_get(dev_handle, rscnt + fsec);	176	b = block_get(dev_handle, rscnt + fsec, bps);
176	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);	177	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
177	assert(clst != FAT_CLST_BAD);	178	assert(clst != FAT_CLST_BAD);
178	assert(clst < FAT_CLST_LAST1);	179	assert(clst < FAT_CLST_LAST1);
179	block_put(b);	180	block_put(b);
180	}	181	}
181		182
182	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +	183	b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
183	offset % spc);	184	offset % spc, bps);
184		185
185	return b;	186	return b;
186	}	187	}
187		188
188	static void fat_node_initialize(fat_node_t *node)	189	static void fat_node_initialize(fat_node_t *node)
189	{	190	{
190	futex_initialize(&node->lock, 1);	191	futex_initialize(&node->lock, 1);
191	node->idx = NULL;	192	node->idx = NULL;
192	node->type = 0;	193	node->type = 0;
193	link_initialize(&node->ffn_link);	194	link_initialize(&node->ffn_link);
194	node->size = 0;	195	node->size = 0;
195	node->lnkcnt = 0;	196	node->lnkcnt = 0;
196	node->refcnt = 0;	197	node->refcnt = 0;
197	node->dirty = false;	198	node->dirty = false;
198	}	199	}
199		200
200	static uint16_t fat_bps_get(dev_handle_t dev_handle)	201	static uint16_t fat_bps_get(dev_handle_t dev_handle)
201	{	202	{
202	block_t *bb;	203	block_t *bb;
203	uint16_t bps;	204	uint16_t bps;
204		205
205	bb = block_get(dev_handle, BS_BLOCK);	206	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
206	assert(bb != NULL);	207	assert(bb != NULL);
207	bps = uint16_t_le2host(FAT_BS(bb)->bps);	208	bps = uint16_t_le2host(FAT_BS(bb)->bps);
208	block_put(bb);	209	block_put(bb);
209		210
210	return bps;	211	return bps;
211	}	212	}
212		213
213	typedef enum {	214	typedef enum {
214	FAT_DENTRY_SKIP,	215	FAT_DENTRY_SKIP,
215	FAT_DENTRY_LAST,	216	FAT_DENTRY_LAST,
216	FAT_DENTRY_VALID	217	FAT_DENTRY_VALID
217	} fat_dentry_clsf_t;	218	} fat_dentry_clsf_t;
218		219
219	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)	220	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
220	{	221	{
221	if (d->attr & FAT_ATTR_VOLLABEL) {	222	if (d->attr & FAT_ATTR_VOLLABEL) {
222	/* volume label entry */	223	/* volume label entry */
223	return FAT_DENTRY_SKIP;	224	return FAT_DENTRY_SKIP;
224	}	225	}
225	if (d->name[0] == FAT_DENTRY_ERASED) {	226	if (d->name[0] == FAT_DENTRY_ERASED) {
226	/* not-currently-used entry */	227	/* not-currently-used entry */
227	return FAT_DENTRY_SKIP;	228	return FAT_DENTRY_SKIP;
228	}	229	}
229	if (d->name[0] == FAT_DENTRY_UNUSED) {	230	if (d->name[0] == FAT_DENTRY_UNUSED) {
230	/* never used entry */	231	/* never used entry */
231	return FAT_DENTRY_LAST;	232	return FAT_DENTRY_LAST;
232	}	233	}
233	if (d->name[0] == FAT_DENTRY_DOT) {	234	if (d->name[0] == FAT_DENTRY_DOT) {
234	/*	235	/*
235	* Most likely '.' or '..'.	236	* Most likely '.' or '..'.
236	* It cannot occur in a regular file name.	237	* It cannot occur in a regular file name.
237	*/	238	*/
238	return FAT_DENTRY_SKIP;	239	return FAT_DENTRY_SKIP;
239	}	240	}
240	return FAT_DENTRY_VALID;	241	return FAT_DENTRY_VALID;
241	}	242	}
242		243
243	static void fat_node_sync(fat_node_t *node)	244	static void fat_node_sync(fat_node_t *node)
244	{	245	{
245	/* TODO */	246	/* TODO */
246	}	247	}
247		248
248	/** Internal version of fat_node_get().	249	/** Internal version of fat_node_get().
249	*	250	*
250	* @param idxp Locked index structure.	251	* @param idxp Locked index structure.
251	*/	252	*/
252	static void fat_node_get_core(fat_idx_t idxp)	253	static void fat_node_get_core(fat_idx_t idxp)
253	{	254	{
254	block_t *b;	255	block_t *b;
255	fat_dentry_t *d;	256	fat_dentry_t *d;
256	fat_node_t *nodep;	257	fat_node_t *nodep;
257	unsigned bps;	258	unsigned bps;
258	unsigned dps;	259	unsigned dps;
259		260
260	if (idxp->nodep) {	261	if (idxp->nodep) {
261	/*	262	/*
262	* We are lucky.	263	* We are lucky.
263	* The node is already instantiated in memory.	264	* The node is already instantiated in memory.
264	*/	265	*/
265	futex_down(&idxp->nodep->lock);	266	futex_down(&idxp->nodep->lock);
266	if (!idxp->nodep->refcnt++)	267	if (!idxp->nodep->refcnt++)
267	list_remove(&nodep->ffn_link);	268	list_remove(&nodep->ffn_link);
268	futex_up(&idxp->nodep->lock);	269	futex_up(&idxp->nodep->lock);
269	return idxp->nodep;	270	return idxp->nodep;
270	}	271	}
271		272
272	/*	273	/*
273	* We must instantiate the node from the file system.	274	* We must instantiate the node from the file system.
274	*/	275	*/
275		276
276	assert(idxp->pfc);	277	assert(idxp->pfc);
277		278
278	futex_down(&ffn_futex);	279	futex_down(&ffn_futex);
279	if (!list_empty(&ffn_head)) {	280	if (!list_empty(&ffn_head)) {
280	/* Try to use a cached free node structure. */	281	/* Try to use a cached free node structure. */
281	fat_idx_t *idxp_tmp;	282	fat_idx_t *idxp_tmp;
282	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);	283	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
283	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)	284	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
284	goto skip_cache;	285	goto skip_cache;
285	idxp_tmp = nodep->idx;	286	idxp_tmp = nodep->idx;
286	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {	287	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
287	futex_up(&nodep->lock);	288	futex_up(&nodep->lock);
288	goto skip_cache;	289	goto skip_cache;
289	}	290	}
290	list_remove(&nodep->ffn_link);	291	list_remove(&nodep->ffn_link);
291	futex_up(&ffn_futex);	292	futex_up(&ffn_futex);
292	if (nodep->dirty)	293	if (nodep->dirty)
293	fat_node_sync(nodep);	294	fat_node_sync(nodep);
294	idxp_tmp->nodep = NULL;	295	idxp_tmp->nodep = NULL;
295	futex_up(&nodep->lock);	296	futex_up(&nodep->lock);
296	futex_up(&idxp_tmp->lock);	297	futex_up(&idxp_tmp->lock);
297	} else {	298	} else {
298	skip_cache:	299	skip_cache:
299	/* Try to allocate a new node structure. */	300	/* Try to allocate a new node structure. */
300	futex_up(&ffn_futex);	301	futex_up(&ffn_futex);
301	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));	302	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
302	if (!nodep)	303	if (!nodep)
303	return NULL;	304	return NULL;
304	}	305	}
305	fat_node_initialize(nodep);	306	fat_node_initialize(nodep);
306		307
307	bps = fat_bps_get(idxp->dev_handle);	308	bps = fat_bps_get(idxp->dev_handle);
308	dps = bps / sizeof(fat_dentry_t);	309	dps = bps / sizeof(fat_dentry_t);
309		310
310	/* Read the block that contains the dentry of interest. */	311	/* Read the block that contains the dentry of interest. */
311	b = _fat_block_get(idxp->dev_handle, idxp->pfc,	312	b = _fat_block_get(idxp->dev_handle, idxp->pfc,
312	(idxp->pdi * sizeof(fat_dentry_t)) / bps);	313	(idxp->pdi * sizeof(fat_dentry_t)) / bps);
313	assert(b);	314	assert(b);
314		315
315	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);	316	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
316	if (d->attr & FAT_ATTR_SUBDIR) {	317	if (d->attr & FAT_ATTR_SUBDIR) {
317	/*	318	/*
318	* The only directory which does not have this bit set is the	319	* The only directory which does not have this bit set is the
319	* root directory itself. The root directory node is handled	320	* root directory itself. The root directory node is handled
320	* and initialized elsewhere.	321	* and initialized elsewhere.
321	*/	322	*/
322	nodep->type = FAT_DIRECTORY;	323	nodep->type = FAT_DIRECTORY;
323	} else {	324	} else {
324	nodep->type = FAT_FILE;	325	nodep->type = FAT_FILE;
325	}	326	}
326	nodep->firstc = uint16_t_le2host(d->firstc);	327	nodep->firstc = uint16_t_le2host(d->firstc);
327	nodep->size = uint32_t_le2host(d->size);	328	nodep->size = uint32_t_le2host(d->size);
328	nodep->lnkcnt = 1;	329	nodep->lnkcnt = 1;
329	nodep->refcnt = 1;	330	nodep->refcnt = 1;
330		331
331	block_put(b);	332	block_put(b);
332		333
333	/* Link the idx structure with the node structure. */	334	/* Link the idx structure with the node structure. */
334	nodep->idx = idxp;	335	nodep->idx = idxp;
335	idxp->nodep = nodep;	336	idxp->nodep = nodep;
336		337
337	return nodep;	338	return nodep;
338	}	339	}
339		340
340	/** Instantiate a FAT in-core node. */	341	/** Instantiate a FAT in-core node. */
341	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)	342	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
342	{	343	{
343	void *node;	344	void *node;
344	fat_idx_t *idxp;	345	fat_idx_t *idxp;
345		346
346	idxp = fat_idx_get_by_index(dev_handle, index);	347	idxp = fat_idx_get_by_index(dev_handle, index);
347	if (!idxp)	348	if (!idxp)
348	return NULL;	349	return NULL;
349	/* idxp->lock held */	350	/* idxp->lock held */
350	node = fat_node_get_core(idxp);	351	node = fat_node_get_core(idxp);
351	futex_up(&idxp->lock);	352	futex_up(&idxp->lock);
352	return node;	353	return node;
353	}	354	}
354		355
355	static void fat_node_put(void *node)	356	static void fat_node_put(void *node)
356	{	357	{
357	fat_node_t nodep = (fat_node_t )node;	358	fat_node_t nodep = (fat_node_t )node;
358		359
359	futex_down(&nodep->lock);	360	futex_down(&nodep->lock);
360	if (!--nodep->refcnt) {	361	if (!--nodep->refcnt) {
361	futex_down(&ffn_futex);	362	futex_down(&ffn_futex);
362	list_append(&nodep->ffn_link, &ffn_head);	363	list_append(&nodep->ffn_link, &ffn_head);
363	futex_up(&ffn_futex);	364	futex_up(&ffn_futex);
364	}	365	}
365	futex_up(&nodep->lock);	366	futex_up(&nodep->lock);
366	}	367	}
367		368
368	static void *fat_create(int flags)	369	static void *fat_create(int flags)
369	{	370	{
370	return NULL; /* not supported at the moment */	371	return NULL; /* not supported at the moment */
371	}	372	}
372		373
373	static int fat_destroy(void *node)	374	static int fat_destroy(void *node)
374	{	375	{
375	return ENOTSUP; /* not supported at the moment */	376	return ENOTSUP; /* not supported at the moment */
376	}	377	}
377		378
378	static bool fat_link(void prnt, void chld, const char *name)	379	static bool fat_link(void prnt, void chld, const char *name)
379	{	380	{
380	return false; /* not supported at the moment */	381	return false; /* not supported at the moment */
381	}	382	}
382		383
383	static int fat_unlink(void prnt, void chld)	384	static int fat_unlink(void prnt, void chld)
384	{	385	{
385	return ENOTSUP; /* not supported at the moment */	386	return ENOTSUP; /* not supported at the moment */
386	}	387	}
387		388
388	static void fat_match(void prnt, const char *component)	389	static void fat_match(void prnt, const char *component)
389	{	390	{
390	fat_node_t parentp = (fat_node_t )prnt;	391	fat_node_t parentp = (fat_node_t )prnt;
391	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	392	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
392	unsigned i, j;	393	unsigned i, j;
393	unsigned bps; /* bytes per sector */	394	unsigned bps; /* bytes per sector */
394	unsigned dps; /* dentries per sector */	395	unsigned dps; /* dentries per sector */
395	unsigned blocks;	396	unsigned blocks;
396	fat_dentry_t *d;	397	fat_dentry_t *d;
397	block_t *b;	398	block_t *b;
398		399
399	futex_down(&parentp->idx->lock);	400	futex_down(&parentp->idx->lock);
400	bps = fat_bps_get(parentp->idx->dev_handle);	401	bps = fat_bps_get(parentp->idx->dev_handle);
401	dps = bps / sizeof(fat_dentry_t);	402	dps = bps / sizeof(fat_dentry_t);
402	blocks = parentp->size / bps + (parentp->size % bps != 0);	403	blocks = parentp->size / bps + (parentp->size % bps != 0);
403	for (i = 0; i < blocks; i++) {	404	for (i = 0; i < blocks; i++) {
404	unsigned dentries;	405	unsigned dentries;
405		406
406	b = fat_block_get(parentp, i);	407	b = fat_block_get(parentp, i);
407	dentries = (i == blocks - 1) ?	408	dentries = (i == blocks - 1) ?
408	parentp->size % sizeof(fat_dentry_t) :	409	parentp->size % sizeof(fat_dentry_t) :
409	dps;	410	dps;
410	for (j = 0; j < dentries; j++) {	411	for (j = 0; j < dentries; j++) {
411	d = ((fat_dentry_t *)b->data) + j;	412	d = ((fat_dentry_t *)b->data) + j;
412	switch (fat_classify_dentry(d)) {	413	switch (fat_classify_dentry(d)) {
413	case FAT_DENTRY_SKIP:	414	case FAT_DENTRY_SKIP:
414	continue;	415	continue;
415	case FAT_DENTRY_LAST:	416	case FAT_DENTRY_LAST:
416	block_put(b);	417	block_put(b);
417	futex_up(&parentp->idx->lock);	418	futex_up(&parentp->idx->lock);
418	return NULL;	419	return NULL;
419	default:	420	default:
420	case FAT_DENTRY_VALID:	421	case FAT_DENTRY_VALID:
421	dentry_name_canonify(d, name);	422	dentry_name_canonify(d, name);
422	break;	423	break;
423	}	424	}
424	if (strcmp(name, component) == 0) {	425	if (strcmp(name, component) == 0) {
425	/* hit */	426	/* hit */
426	void *node;	427	void *node;
427	/*	428	/*
428	* Assume tree hierarchy for locking. We	429	* Assume tree hierarchy for locking. We
429	* already have the parent and now we are going	430	* already have the parent and now we are going
430	* to lock the child. Never lock in the oposite	431	* to lock the child. Never lock in the oposite
431	* order.	432	* order.
432	*/	433	*/
433	fat_idx_t *idx = fat_idx_get_by_pos(	434	fat_idx_t *idx = fat_idx_get_by_pos(
434	parentp->idx->dev_handle, parentp->firstc,	435	parentp->idx->dev_handle, parentp->firstc,
435	i * dps + j);	436	i * dps + j);
436	futex_up(&parentp->idx->lock);	437	futex_up(&parentp->idx->lock);
437	if (!idx) {	438	if (!idx) {
438	/*	439	/*
439	* Can happen if memory is low or if we	440	* Can happen if memory is low or if we
440	* run out of 32-bit indices.	441	* run out of 32-bit indices.
441	*/	442	*/
442	block_put(b);	443	block_put(b);
443	return NULL;	444	return NULL;
444	}	445	}
445	node = fat_node_get_core(idx);	446	node = fat_node_get_core(idx);
446	futex_up(&idx->lock);	447	futex_up(&idx->lock);
447	block_put(b);	448	block_put(b);
448	return node;	449	return node;
449	}	450	}
450	}	451	}
451	block_put(b);	452	block_put(b);
452	}	453	}
453	futex_up(&parentp->idx->lock);	454	futex_up(&parentp->idx->lock);
454	return NULL;	455	return NULL;
455	}	456	}
456		457
457	static fs_index_t fat_index_get(void *node)	458	static fs_index_t fat_index_get(void *node)
458	{	459	{
459	fat_node_t fnodep = (fat_node_t )node;	460	fat_node_t fnodep = (fat_node_t )node;
460	if (!fnodep)	461	if (!fnodep)
461	return 0;	462	return 0;
462	return fnodep->idx->index;	463	return fnodep->idx->index;
463	}	464	}
464		465
465	static size_t fat_size_get(void *node)	466	static size_t fat_size_get(void *node)
466	{	467	{
467	return ((fat_node_t *)node)->size;	468	return ((fat_node_t *)node)->size;
468	}	469	}
469		470
470	static unsigned fat_lnkcnt_get(void *node)	471	static unsigned fat_lnkcnt_get(void *node)
471	{	472	{
472	return ((fat_node_t *)node)->lnkcnt;	473	return ((fat_node_t *)node)->lnkcnt;
473	}	474	}
474		475
475	static bool fat_has_children(void *node)	476	static bool fat_has_children(void *node)
476	{	477	{
477	fat_node_t nodep = (fat_node_t )node;	478	fat_node_t nodep = (fat_node_t )node;
478	unsigned bps;	479	unsigned bps;
479	unsigned dps;	480	unsigned dps;
480	unsigned blocks;	481	unsigned blocks;
481	block_t *b;	482	block_t *b;
482	unsigned i, j;	483	unsigned i, j;
483		484
484	if (nodep->type != FAT_DIRECTORY)	485	if (nodep->type != FAT_DIRECTORY)
485	return false;	486	return false;
486		487
487	futex_down(&nodep->idx->lock);	488	futex_down(&nodep->idx->lock);
488	bps = fat_bps_get(nodep->idx->dev_handle);	489	bps = fat_bps_get(nodep->idx->dev_handle);
489	dps = bps / sizeof(fat_dentry_t);	490	dps = bps / sizeof(fat_dentry_t);
490		491
491	blocks = nodep->size / bps + (nodep->size % bps != 0);	492	blocks = nodep->size / bps + (nodep->size % bps != 0);
492		493
493	for (i = 0; i < blocks; i++) {	494	for (i = 0; i < blocks; i++) {
494	unsigned dentries;	495	unsigned dentries;
495	fat_dentry_t *d;	496	fat_dentry_t *d;
496		497
497	b = fat_block_get(nodep, i);	498	b = fat_block_get(nodep, i);
498	dentries = (i == blocks - 1) ?	499	dentries = (i == blocks - 1) ?
499	nodep->size % sizeof(fat_dentry_t) :	500	nodep->size % sizeof(fat_dentry_t) :

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 3119 → 3253