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 "fat_dentry.h"
#include "fat_fat.h"
#include "../../vfs/vfs.h"
#include <libfs.h>
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <ipc/devmap.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>
#include <sys/mman.h>
#include <align.h>
 
/** 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);
 
static int dev_phone = -1;      /* FIXME */
static void *dev_buffer = NULL;     /* FIXME */
 
block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
{
    /* FIXME */
    block_t *b;
    off_t bufpos = 0;
    size_t buflen = 0;
    off_t pos = offset * bs;
 
    assert(dev_phone != -1);
    assert(dev_buffer);
 
    b = malloc(sizeof(block_t));
    if (!b)
        return NULL;
   
    b->data = malloc(bs);
    if (!b->data) {
        free(b);
        return NULL;
    }
    b->size = bs;
 
    if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos,
        b->data, bs, bs)) {
        free(b->data);
        free(b);
        return NULL;
    }
 
    return b;
}
 
void block_put(block_t *block)
{
    /* FIXME */
    free(block->data);
    free(block);
}
 
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 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 *bb, *b;
    fat_dentry_t *d;
    fat_node_t *nodep = NULL;
    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(&idxp->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);
 
    bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    dps = bps / sizeof(fat_dentry_t);
 
    /* Read the block that contains the dentry of interest. */
    b = _fat_block_get(bb->data, 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;
        /*
         * Unfortunately, the 'size' field of the FAT dentry is not
         * defined for the directory entry type. We must determine the
         * size of the directory by walking the FAT.
         */
        nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,
            uint16_t_le2host(d->firstc), NULL);
    } else {
        nodep->type = FAT_FILE;
        nodep->size = uint32_t_le2host(d->size);
    }
    nodep->firstc = uint16_t_le2host(d->firstc);
    nodep->lnkcnt = 1;
    nodep->refcnt = 1;
 
    block_put(b);
    block_put(bb);
 
    /* 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 *bb, *b;
 
    futex_down(&parentp->idx->lock);
    bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    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(bb->data, 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);
                block_put(bb);
                futex_up(&parentp->idx->lock);
                return NULL;
            default:
            case FAT_DENTRY_VALID:
                dentry_name_canonify(d, name);
                break;
            }
            if (stricmp(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);
                    block_put(bb);
                    return NULL;
                }
                node = fat_node_get_core(idx);
                futex_up(&idx->lock);
                block_put(b);
                block_put(bb);
                return node;
            }
        }
        block_put(b);
    }
    block_put(bb);
 
    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 *bb, *b;
    unsigned i, j;
 
    if (nodep->type != FAT_DIRECTORY)
        return false;
 
    futex_down(&nodep->idx->lock);
    bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    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(bb->data, 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);
                block_put(bb);
                futex_up(&nodep->idx->lock);
                return false;
            default:
            case FAT_DENTRY_VALID:
                block_put(b);
                block_put(bb);
                futex_up(&nodep->idx->lock);
                return true;
            }
            block_put(b);
            block_put(bb);
            futex_up(&nodep->idx->lock);
            return true;
        }
        block_put(b);
    }
    block_put(bb);
 
    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 bps;
    uint16_t rde;
    int rc;
 
    /*
     * For now, we don't bother to remember dev_handle, dev_phone or
     * dev_buffer in some data structure. We use global variables because we
     * know there will be at most one mount on this file system.
     * Of course, this is a huge TODO item.
     */
    dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ | PROTO_WRITE,
        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
   
    if (!dev_buffer) {
        ipc_answer_0(rid, ENOMEM);
        return;
    }
 
    dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
        DEVMAP_CONNECT_TO_DEVICE, dev_handle);
 
    if (dev_phone < 0) {
        munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, dev_phone);
        return;
    }
 
    rc = ipc_share_out_start(dev_phone, dev_buffer,
        AS_AREA_READ | AS_AREA_WRITE);
    if (rc != EOK) {
            munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, rc);
        return;
    }
 
    /* Read the number of root directory entries. */
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
    block_put(bb);
 
    if (bps != BS_SIZE) {
        munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, ENOTSUP);
        return;
    }
 
    rc = fat_idx_init_by_dev_handle(dev_handle);
    if (rc != EOK) {
            munmap(dev_buffer, BS_SIZE);
        ipc_answer_0(rid, rc);
        return;
    }
 
    /* Initialize the root node. */
    fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t));
    if (!rootp) {
            munmap(dev_buffer, BS_SIZE);
        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) {
            munmap(dev_buffer, BS_SIZE);
        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->lnkcnt = 0;  /* FS root is not linked */
    rootp->size = rde * sizeof(fat_dentry_t);
    rootp->idx = ridxp;
    ridxp->nodep = rootp;
   
    futex_up(&ridxp->lock);
 
    ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt);
}
 
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);
}
 
void fat_read(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
    fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index);
    uint16_t bps;
    size_t bytes;
    block_t *bb, *b;
 
    if (!nodep) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
 
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_read_receive(&callid, &len)) {
        fat_node_put(nodep);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
 
    if (nodep->type == FAT_FILE) {
        /*
         * Our strategy for regular file reads is to read one block at
         * most and make use of the possibility to return less data than
         * requested. This keeps the code very simple.
         */
        bytes = min(len, bps - pos % bps);
        b = fat_block_get(bb->data, nodep, pos / bps);
        (void) ipc_data_read_finalize(callid, b->data + pos % bps,
            bytes);
        block_put(b);
    } else {
        unsigned bnum;
        off_t spos = pos;
        char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
        fat_dentry_t *d;
 
        assert(nodep->type == FAT_DIRECTORY);
        assert(nodep->size % bps == 0);
        assert(bps % sizeof(fat_dentry_t) == 0);
 
        /*
         * Our strategy for readdir() is to use the position pointer as
         * an index into the array of all dentries. On entry, it points
         * to the first unread dentry. If we skip any dentries, we bump
         * the position pointer accordingly.
         */
        bnum = (pos * sizeof(fat_dentry_t)) / bps;
        while (bnum < nodep->size / bps) {
            off_t o;
 
            b = fat_block_get(bb->data, nodep, bnum);
            for (o = pos % (bps / sizeof(fat_dentry_t));
                o < bps / sizeof(fat_dentry_t);
                o++, pos++) {
                d = ((fat_dentry_t *)b->data) + o;
                switch (fat_classify_dentry(d)) {
                case FAT_DENTRY_SKIP:
                    continue;
                case FAT_DENTRY_LAST:
                    block_put(b);
                    goto miss;
                default:
                case FAT_DENTRY_VALID:
                    dentry_name_canonify(d, name);
                    block_put(b);
                    goto hit;
                }
            }
            block_put(b);
            bnum++;
        }
miss:
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_0(callid, ENOENT);
        ipc_answer_1(rid, ENOENT, 0);
        return;
hit:
        (void) ipc_data_read_finalize(callid, name, strlen(name) + 1);
        bytes = (pos - spos) + 1;
    }
 
    fat_node_put(nodep);
    block_put(bb);
    ipc_answer_1(rid, EOK, (ipcarg_t)bytes);
}
 
void fat_write(ipc_callid_t rid, ipc_call_t *request)
{
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
    off_t pos = (off_t)IPC_GET_ARG3(*request);
    fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index);
    size_t bytes;
    block_t *b, *bb;
    uint16_t bps;
    unsigned spc;
    off_t boundary;
   
    if (!nodep) {
        ipc_answer_0(rid, ENOENT);
        return;
    }
   
    /* XXX remove me when you are ready */
    {
        ipc_answer_0(rid, ENOTSUP);
        fat_node_put(nodep);
        return;
    }
 
    ipc_callid_t callid;
    size_t len;
    if (!ipc_data_write_receive(&callid, &len)) {
        fat_node_put(nodep);
        ipc_answer_0(callid, EINVAL);
        ipc_answer_0(rid, EINVAL);
        return;
    }
 
    /*
     * In all scenarios, we will attempt to write out only one block worth
     * of data at maximum. There might be some more efficient approaches,
     * but this one greatly simplifies fat_write(). Note that we can afford
     * to do this because the client must be ready to handle the return
     * value signalizing a smaller number of bytes written.
     */
    bytes = min(len, bps - pos % bps);
 
    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
    bps = uint16_t_le2host(FAT_BS(bb)->bps);
    spc = FAT_BS(bb)->spc;
 
   
    boundary = ROUND_UP(nodep->size, bps * spc);
    if (pos < boundary) {
        /*
         * This is the easier case - we are either overwriting already
         * existing contents or writing behind the EOF, but still within
         * the limits of the last cluster. The node size may grow to the
         * next block size boundary.
         */
        fat_fill_gap(bb->data, nodep, FAT_CLST_RES0, pos);
        b = fat_block_get(bb->data, nodep, pos / bps);
        (void) ipc_data_write_finalize(callid, b->data + pos % bps,
            bytes);
        b->dirty = true;        /* need to sync block */
        block_put(b);
        if (pos + bytes > nodep->size) {
            nodep->size = pos + bytes;
            nodep->dirty = true;    /* need to sync node */
        }
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_1(rid, EOK, bytes); 
        return;
    } else {
        /*
         * This is the more difficult case. We must allocate new
         * clusters for the node and zero them out.
         */
        int status;
        unsigned nclsts;
        fat_cluster_t mcl, lcl;
   
        nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) /
            bps * spc;
        /* create an independent chain of nclsts clusters in all FATs */
        status = fat_alloc_clusters(bb->data, dev_handle, nclsts, &mcl,
            &lcl);
        if (status != EOK) {
            /* could not allocate a chain of nclsts clusters */
            fat_node_put(nodep);
            block_put(bb);
            ipc_answer_0(callid, status);
            ipc_answer_0(rid, status);
            return;
        }
        /* zero fill any gaps */
        fat_fill_gap(bb->data, nodep, mcl, pos);
        b = _fat_block_get(bb->data, dev_handle, lcl,
            (pos / bps) % spc);
        (void) ipc_data_write_finalize(callid, b->data + pos % bps,
            bytes);
        b->dirty = true;        /* need to sync block */
        block_put(b);
        /*
         * Append the cluster chain starting in mcl to the end of the
         * node's cluster chain.
         */
        fat_append_clusters(bb->data, nodep, mcl);
        nodep->size = pos + bytes;
        nodep->dirty = true;        /* need to sync node */
        fat_node_put(nodep);
        block_put(bb);
        ipc_answer_1(rid, EOK, bytes);
        return;
    }
}
 
/**
 * @}
 */
 

Rev 3513	Rev 3516
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 "fat_dentry.h"	39	#include "fat_dentry.h"
40	#include "fat_fat.h"	40	#include "fat_fat.h"
41	#include "../../vfs/vfs.h"	41	#include "../../vfs/vfs.h"
42	#include <libfs.h>	42	#include <libfs.h>
43	#include <ipc/ipc.h>	43	#include <ipc/ipc.h>
44	#include <ipc/services.h>	44	#include <ipc/services.h>
45	#include <ipc/devmap.h>	45	#include <ipc/devmap.h>
46	#include <async.h>	46	#include <async.h>
47	#include <errno.h>	47	#include <errno.h>
48	#include <string.h>	48	#include <string.h>
49	#include <byteorder.h>	49	#include <byteorder.h>
50	#include <libadt/hash_table.h>	50	#include <libadt/hash_table.h>
51	#include <libadt/list.h>	51	#include <libadt/list.h>
52	#include <assert.h>	52	#include <assert.h>
53	#include <futex.h>	53	#include <futex.h>
54	#include <sys/mman.h>	54	#include <sys/mman.h>
55	#include <align.h>	55	#include <align.h>
56		56
57	/** Futex protecting the list of cached free FAT nodes. */	57	/** Futex protecting the list of cached free FAT nodes. */
58	static futex_t ffn_futex = FUTEX_INITIALIZER;	58	static futex_t ffn_futex = FUTEX_INITIALIZER;
59		59
60	/** List of cached free FAT nodes. */	60	/** List of cached free FAT nodes. */
61	static LIST_INITIALIZE(ffn_head);	61	static LIST_INITIALIZE(ffn_head);
62		62
63	static int dev_phone = -1; /* FIXME */	63	static int dev_phone = -1; /* FIXME */
64	static void dev_buffer = NULL; / FIXME */	64	static void dev_buffer = NULL; / FIXME */
65		65
66	block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)	66	block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)
67	{	67	{
68	/* FIXME */	68	/* FIXME */
69	block_t *b;	69	block_t *b;
70	off_t bufpos = 0;	70	off_t bufpos = 0;
71	size_t buflen = 0;	71	size_t buflen = 0;
72	off_t pos = offset * bs;	72	off_t pos = offset * bs;
73		73
74	assert(dev_phone != -1);	74	assert(dev_phone != -1);
75	assert(dev_buffer);	75	assert(dev_buffer);
76		76
77	b = malloc(sizeof(block_t));	77	b = malloc(sizeof(block_t));
78	if (!b)	78	if (!b)
79	return NULL;	79	return NULL;
80		80
81	b->data = malloc(bs);	81	b->data = malloc(bs);
82	if (!b->data) {	82	if (!b->data) {
83	free(b);	83	free(b);
84	return NULL;	84	return NULL;
85	}	85	}
86	b->size = bs;	86	b->size = bs;
87		87
88	if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos,	88	if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos,
89	b->data, bs, bs)) {	89	b->data, bs, bs)) {
90	free(b->data);	90	free(b->data);
91	free(b);	91	free(b);
92	return NULL;	92	return NULL;
93	}	93	}
94		94
95	return b;	95	return b;
96	}	96	}
97		97
98	void block_put(block_t *block)	98	void block_put(block_t *block)
99	{	99	{
100	/* FIXME */	100	/* FIXME */
101	free(block->data);	101	free(block->data);
102	free(block);	102	free(block);
103	}	103	}
104		104
105	static void fat_node_initialize(fat_node_t *node)	105	static void fat_node_initialize(fat_node_t *node)
106	{	106	{
107	futex_initialize(&node->lock, 1);	107	futex_initialize(&node->lock, 1);
108	node->idx = NULL;	108	node->idx = NULL;
109	node->type = 0;	109	node->type = 0;
110	link_initialize(&node->ffn_link);	110	link_initialize(&node->ffn_link);
111	node->size = 0;	111	node->size = 0;
112	node->lnkcnt = 0;	112	node->lnkcnt = 0;
113	node->refcnt = 0;	113	node->refcnt = 0;
114	node->dirty = false;	114	node->dirty = false;
115	}	115	}
116		116
117	static void fat_node_sync(fat_node_t *node)	117	static void fat_node_sync(fat_node_t *node)
118	{	118	{
119	/* TODO */	119	/* TODO */
120	}	120	}
121		121
122	/** Internal version of fat_node_get().	122	/** Internal version of fat_node_get().
123	*	123	*
124	* @param idxp Locked index structure.	124	* @param idxp Locked index structure.
125	*/	125	*/
126	static void fat_node_get_core(fat_idx_t idxp)	126	static void fat_node_get_core(fat_idx_t idxp)
127	{	127	{
128	block_t *b;	128	block_t bb, b;
129	fat_dentry_t *d;	129	fat_dentry_t *d;
130	fat_node_t *nodep = NULL;	130	fat_node_t *nodep = NULL;
131	unsigned bps;	131	unsigned bps;
132	unsigned dps;	132	unsigned dps;
133		133
134	if (idxp->nodep) {	134	if (idxp->nodep) {
135	/*	135	/*
136	* We are lucky.	136	* We are lucky.
137	* The node is already instantiated in memory.	137	* The node is already instantiated in memory.
138	*/	138	*/
139	futex_down(&idxp->nodep->lock);	139	futex_down(&idxp->nodep->lock);
140	if (!idxp->nodep->refcnt++)	140	if (!idxp->nodep->refcnt++)
141	list_remove(&idxp->nodep->ffn_link);	141	list_remove(&idxp->nodep->ffn_link);
142	futex_up(&idxp->nodep->lock);	142	futex_up(&idxp->nodep->lock);
143	return idxp->nodep;	143	return idxp->nodep;
144	}	144	}
145		145
146	/*	146	/*
147	* We must instantiate the node from the file system.	147	* We must instantiate the node from the file system.
148	*/	148	*/
149		149
150	assert(idxp->pfc);	150	assert(idxp->pfc);
151		151
152	futex_down(&ffn_futex);	152	futex_down(&ffn_futex);
153	if (!list_empty(&ffn_head)) {	153	if (!list_empty(&ffn_head)) {
154	/* Try to use a cached free node structure. */	154	/* Try to use a cached free node structure. */
155	fat_idx_t *idxp_tmp;	155	fat_idx_t *idxp_tmp;
156	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);	156	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
157	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)	157	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
158	goto skip_cache;	158	goto skip_cache;
159	idxp_tmp = nodep->idx;	159	idxp_tmp = nodep->idx;
160	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {	160	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
161	futex_up(&nodep->lock);	161	futex_up(&nodep->lock);
162	goto skip_cache;	162	goto skip_cache;
163	}	163	}
164	list_remove(&nodep->ffn_link);	164	list_remove(&nodep->ffn_link);
165	futex_up(&ffn_futex);	165	futex_up(&ffn_futex);
166	if (nodep->dirty)	166	if (nodep->dirty)
167	fat_node_sync(nodep);	167	fat_node_sync(nodep);
168	idxp_tmp->nodep = NULL;	168	idxp_tmp->nodep = NULL;
169	futex_up(&nodep->lock);	169	futex_up(&nodep->lock);
170	futex_up(&idxp_tmp->lock);	170	futex_up(&idxp_tmp->lock);
171	} else {	171	} else {
172	skip_cache:	172	skip_cache:
173	/* Try to allocate a new node structure. */	173	/* Try to allocate a new node structure. */
174	futex_up(&ffn_futex);	174	futex_up(&ffn_futex);
175	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));	175	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
176	if (!nodep)	176	if (!nodep)
177	return NULL;	177	return NULL;
178	}	178	}
179	fat_node_initialize(nodep);	179	fat_node_initialize(nodep);
180		180
181	bps = fat_bps_get(idxp->dev_handle);	181	bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);
-		182	bps = uint16_t_le2host(FAT_BS(bb)->bps);
182	dps = bps / sizeof(fat_dentry_t);	183	dps = bps / sizeof(fat_dentry_t);
183		184
184	/* Read the block that contains the dentry of interest. */	185	/* Read the block that contains the dentry of interest. */
185	b = _fat_block_get(idxp->dev_handle, idxp->pfc,	186	b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,
186	(idxp->pdi * sizeof(fat_dentry_t)) / bps);	187	(idxp->pdi * sizeof(fat_dentry_t)) / bps);
187	assert(b);	188	assert(b);
188		189
189	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);	190	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
190	if (d->attr & FAT_ATTR_SUBDIR) {	191	if (d->attr & FAT_ATTR_SUBDIR) {
191	/*	192	/*
192	* The only directory which does not have this bit set is the	193	* The only directory which does not have this bit set is the
193	* root directory itself. The root directory node is handled	194	* root directory itself. The root directory node is handled
194	* and initialized elsewhere.	195	* and initialized elsewhere.
195	*/	196	*/
196	nodep->type = FAT_DIRECTORY;	197	nodep->type = FAT_DIRECTORY;
197	/*	198	/*
198	* Unfortunately, the 'size' field of the FAT dentry is not	199	* Unfortunately, the 'size' field of the FAT dentry is not
199	* defined for the directory entry type. We must determine the	200	* defined for the directory entry type. We must determine the
200	* size of the directory by walking the FAT.	201	* size of the directory by walking the FAT.
201	*/	202	*/
202	nodep->size = bps * _fat_blcks_get(idxp->dev_handle,	203	nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,
203	uint16_t_le2host(d->firstc), NULL);	204	uint16_t_le2host(d->firstc), NULL);
204	} else {	205	} else {
205	nodep->type = FAT_FILE;	206	nodep->type = FAT_FILE;
206	nodep->size = uint32_t_le2host(d->size);	207	nodep->size = uint32_t_le2host(d->size);
207	}	208	}
208	nodep->firstc = uint16_t_le2host(d->firstc);	209	nodep->firstc = uint16_t_le2host(d->firstc);
209	nodep->lnkcnt = 1;	210	nodep->lnkcnt = 1;
210	nodep->refcnt = 1;	211	nodep->refcnt = 1;
211		212
212	block_put(b);	213	block_put(b);
-		214	block_put(bb);
213		215
214	/* Link the idx structure with the node structure. */	216	/* Link the idx structure with the node structure. */
215	nodep->idx = idxp;	217	nodep->idx = idxp;
216	idxp->nodep = nodep;	218	idxp->nodep = nodep;
217		219
218	return nodep;	220	return nodep;
219	}	221	}
220		222
221	/** Instantiate a FAT in-core node. */	223	/** Instantiate a FAT in-core node. */
222	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)	224	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
223	{	225	{
224	void *node;	226	void *node;
225	fat_idx_t *idxp;	227	fat_idx_t *idxp;
226		228
227	idxp = fat_idx_get_by_index(dev_handle, index);	229	idxp = fat_idx_get_by_index(dev_handle, index);
228	if (!idxp)	230	if (!idxp)
229	return NULL;	231	return NULL;
230	/* idxp->lock held */	232	/* idxp->lock held */
231	node = fat_node_get_core(idxp);	233	node = fat_node_get_core(idxp);
232	futex_up(&idxp->lock);	234	futex_up(&idxp->lock);
233	return node;	235	return node;
234	}	236	}
235		237
236	static void fat_node_put(void *node)	238	static void fat_node_put(void *node)
237	{	239	{
238	fat_node_t nodep = (fat_node_t )node;	240	fat_node_t nodep = (fat_node_t )node;
239		241
240	futex_down(&nodep->lock);	242	futex_down(&nodep->lock);
241	if (!--nodep->refcnt) {	243	if (!--nodep->refcnt) {
242	futex_down(&ffn_futex);	244	futex_down(&ffn_futex);
243	list_append(&nodep->ffn_link, &ffn_head);	245	list_append(&nodep->ffn_link, &ffn_head);
244	futex_up(&ffn_futex);	246	futex_up(&ffn_futex);
245	}	247	}
246	futex_up(&nodep->lock);	248	futex_up(&nodep->lock);
247	}	249	}
248		250
249	static void *fat_create(int flags)	251	static void *fat_create(int flags)
250	{	252	{
251	return NULL; /* not supported at the moment */	253	return NULL; /* not supported at the moment */
252	}	254	}
253		255
254	static int fat_destroy(void *node)	256	static int fat_destroy(void *node)
255	{	257	{
256	return ENOTSUP; /* not supported at the moment */	258	return ENOTSUP; /* not supported at the moment */
257	}	259	}
258		260
259	static bool fat_link(void prnt, void chld, const char *name)	261	static bool fat_link(void prnt, void chld, const char *name)
260	{	262	{
261	return false; /* not supported at the moment */	263	return false; /* not supported at the moment */
262	}	264	}
263		265
264	static int fat_unlink(void prnt, void chld)	266	static int fat_unlink(void prnt, void chld)
265	{	267	{
266	return ENOTSUP; /* not supported at the moment */	268	return ENOTSUP; /* not supported at the moment */
267	}	269	}
268		270
269	static void fat_match(void prnt, const char *component)	271	static void fat_match(void prnt, const char *component)
270	{	272	{
271	fat_node_t parentp = (fat_node_t )prnt;	273	fat_node_t parentp = (fat_node_t )prnt;
272	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	274	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
273	unsigned i, j;	275	unsigned i, j;
274	unsigned bps; /* bytes per sector */	276	unsigned bps; /* bytes per sector */
275	unsigned dps; /* dentries per sector */	277	unsigned dps; /* dentries per sector */
276	unsigned blocks;	278	unsigned blocks;
277	fat_dentry_t *d;	279	fat_dentry_t *d;
278	block_t *b;	280	block_t bb, b;
279		281
280	futex_down(&parentp->idx->lock);	282	futex_down(&parentp->idx->lock);
281	bps = fat_bps_get(parentp->idx->dev_handle);	283	bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);
-		284	bps = uint16_t_le2host(FAT_BS(bb)->bps);
282	dps = bps / sizeof(fat_dentry_t);	285	dps = bps / sizeof(fat_dentry_t);
283	blocks = parentp->size / bps + (parentp->size % bps != 0);	286	blocks = parentp->size / bps + (parentp->size % bps != 0);
284	for (i = 0; i < blocks; i++) {	287	for (i = 0; i < blocks; i++) {
285	unsigned dentries;	288	unsigned dentries;
286		289
287	b = fat_block_get(parentp, i);	290	b = fat_block_get(bb->data, parentp, i);
288	dentries = (i == blocks - 1) ?	291	dentries = (i == blocks - 1) ?
289	parentp->size % sizeof(fat_dentry_t) :	292	parentp->size % sizeof(fat_dentry_t) :
290	dps;	293	dps;
291	for (j = 0; j < dentries; j++) {	294	for (j = 0; j < dentries; j++) {
292	d = ((fat_dentry_t *)b->data) + j;	295	d = ((fat_dentry_t *)b->data) + j;
293	switch (fat_classify_dentry(d)) {	296	switch (fat_classify_dentry(d)) {
294	case FAT_DENTRY_SKIP:	297	case FAT_DENTRY_SKIP:
295	continue;	298	continue;
296	case FAT_DENTRY_LAST:	299	case FAT_DENTRY_LAST:
297	block_put(b);	300	block_put(b);
-		301	block_put(bb);
298	futex_up(&parentp->idx->lock);	302	futex_up(&parentp->idx->lock);
299	return NULL;	303	return NULL;
300	default:	304	default:
301	case FAT_DENTRY_VALID:	305	case FAT_DENTRY_VALID:
302	dentry_name_canonify(d, name);	306	dentry_name_canonify(d, name);
303	break;	307	break;
304	}	308	}
305	if (stricmp(name, component) == 0) {	309	if (stricmp(name, component) == 0) {
306	/* hit */	310	/* hit */
307	void *node;	311	void *node;
308	/*	312	/*
309	* Assume tree hierarchy for locking. We	313	* Assume tree hierarchy for locking. We
310	* already have the parent and now we are going	314	* already have the parent and now we are going
311	* to lock the child. Never lock in the oposite	315	* to lock the child. Never lock in the oposite
312	* order.	316	* order.
313	*/	317	*/
314	fat_idx_t *idx = fat_idx_get_by_pos(	318	fat_idx_t *idx = fat_idx_get_by_pos(
315	parentp->idx->dev_handle, parentp->firstc,	319	parentp->idx->dev_handle, parentp->firstc,
316	i * dps + j);	320	i * dps + j);
317	futex_up(&parentp->idx->lock);	321	futex_up(&parentp->idx->lock);
318	if (!idx) {	322	if (!idx) {
319	/*	323	/*
320	* Can happen if memory is low or if we	324	* Can happen if memory is low or if we
321	* run out of 32-bit indices.	325	* run out of 32-bit indices.
322	*/	326	*/
323	block_put(b);	327	block_put(b);
-		328	block_put(bb);
324	return NULL;	329	return NULL;
325	}	330	}
326	node = fat_node_get_core(idx);	331	node = fat_node_get_core(idx);
327	futex_up(&idx->lock);	332	futex_up(&idx->lock);
328	block_put(b);	333	block_put(b);
-		334	block_put(bb);
329	return node;	335	return node;
330	}	336	}
331	}	337	}
332	block_put(b);	338	block_put(b);
333	}	339	}
-		340	block_put(bb);
-		341
334	futex_up(&parentp->idx->lock);	342	futex_up(&parentp->idx->lock);
335	return NULL;	343	return NULL;
336	}	344	}
337		345
338	static fs_index_t fat_index_get(void *node)	346	static fs_index_t fat_index_get(void *node)
339	{	347	{
340	fat_node_t fnodep = (fat_node_t )node;	348	fat_node_t fnodep = (fat_node_t )node;
341	if (!fnodep)	349	if (!fnodep)
342	return 0;	350	return 0;
343	return fnodep->idx->index;	351	return fnodep->idx->index;
344	}	352	}
345		353
346	static size_t fat_size_get(void *node)	354	static size_t fat_size_get(void *node)
347	{	355	{
348	return ((fat_node_t *)node)->size;	356	return ((fat_node_t *)node)->size;
349	}	357	}
350		358
351	static unsigned fat_lnkcnt_get(void *node)	359	static unsigned fat_lnkcnt_get(void *node)
352	{	360	{
353	return ((fat_node_t *)node)->lnkcnt;	361	return ((fat_node_t *)node)->lnkcnt;
354	}	362	}
355		363
356	static bool fat_has_children(void *node)	364	static bool fat_has_children(void *node)
357	{	365	{
358	fat_node_t nodep = (fat_node_t )node;	366	fat_node_t nodep = (fat_node_t )node;
359	unsigned bps;	367	unsigned bps;
360	unsigned dps;	368	unsigned dps;
361	unsigned blocks;	369	unsigned blocks;
362	block_t *b;	370	block_t bb, b;
363	unsigned i, j;	371	unsigned i, j;
364		372
365	if (nodep->type != FAT_DIRECTORY)	373	if (nodep->type != FAT_DIRECTORY)
366	return false;	374	return false;
367		375
368	futex_down(&nodep->idx->lock);	376	futex_down(&nodep->idx->lock);
369	bps = fat_bps_get(nodep->idx->dev_handle);	377	bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
-		378	bps = uint16_t_le2host(FAT_BS(bb)->bps);
370	dps = bps / sizeof(fat_dentry_t);	379	dps = bps / sizeof(fat_dentry_t);
371		380
372	blocks = nodep->size / bps + (nodep->size % bps != 0);	381	blocks = nodep->size / bps + (nodep->size % bps != 0);
373		382
374	for (i = 0; i < blocks; i++) {	383	for (i = 0; i < blocks; i++) {
375	unsigned dentries;	384	unsigned dentries;
376	fat_dentry_t *d;	385	fat_dentry_t *d;
377		386
378	b = fat_block_get(nodep, i);	387	b = fat_block_get(bb->data, nodep, i);
379	dentries = (i == blocks - 1) ?	388	dentries = (i == blocks - 1) ?
380	nodep->size % sizeof(fat_dentry_t) :	389	nodep->size % sizeof(fat_dentry_t) :
381	dps;	390	dps;
382	for (j = 0; j < dentries; j++) {	391	for (j = 0; j < dentries; j++) {
383	d = ((fat_dentry_t *)b->data) + j;	392	d = ((fat_dentry_t *)b->data) + j;
384	switch (fat_classify_dentry(d)) {	393	switch (fat_classify_dentry(d)) {
385	case FAT_DENTRY_SKIP:	394	case FAT_DENTRY_SKIP:
386	continue;	395	continue;
387	case FAT_DENTRY_LAST:	396	case FAT_DENTRY_LAST:
388	block_put(b);	397	block_put(b);
-		398	block_put(bb);
389	futex_up(&nodep->idx->lock);	399	futex_up(&nodep->idx->lock);
390	return false;	400	return false;
391	default:	401	default:
392	case FAT_DENTRY_VALID:	402	case FAT_DENTRY_VALID:
393	block_put(b);	403	block_put(b);
-		404	block_put(bb);
394	futex_up(&nodep->idx->lock);	405	futex_up(&nodep->idx->lock);
395	return true;	406	return true;
396	}	407	}
397	block_put(b);	408	block_put(b);
-		409	block_put(bb);
398	futex_up(&nodep->idx->lock);	410	futex_up(&nodep->idx->lock);
399	return true;	411	return true;
400	}	412	}
401	block_put(b);	413	block_put(b);
402	}	414	}
-		415	block_put(bb);
403		416
404	futex_up(&nodep->idx->lock);	417	futex_up(&nodep->idx->lock);
405	return false;	418	return false;
406	}	419	}
407		420
408	static void *fat_root_get(dev_handle_t dev_handle)	421	static void *fat_root_get(dev_handle_t dev_handle)
409	{	422	{
410	return fat_node_get(dev_handle, 0);	423	return fat_node_get(dev_handle, 0);
411	}	424	}
412		425
413	static char fat_plb_get_char(unsigned pos)	426	static char fat_plb_get_char(unsigned pos)
414	{	427	{
415	return fat_reg.plb_ro[pos % PLB_SIZE];	428	return fat_reg.plb_ro[pos % PLB_SIZE];
416	}	429	}
417		430
418	static bool fat_is_directory(void *node)	431	static bool fat_is_directory(void *node)
419	{	432	{
420	return ((fat_node_t *)node)->type == FAT_DIRECTORY;	433	return ((fat_node_t *)node)->type == FAT_DIRECTORY;
421	}	434	}
422		435
423	static bool fat_is_file(void *node)	436	static bool fat_is_file(void *node)
424	{	437	{
425	return ((fat_node_t *)node)->type == FAT_FILE;	438	return ((fat_node_t *)node)->type == FAT_FILE;
426	}	439	}
427		440
428	/** libfs operations */	441	/** libfs operations */
429	libfs_ops_t fat_libfs_ops = {	442	libfs_ops_t fat_libfs_ops = {
430	.match = fat_match,	443	.match = fat_match,
431	.node_get = fat_node_get,	444	.node_get = fat_node_get,
432	.node_put = fat_node_put,	445	.node_put = fat_node_put,
433	.create = fat_create,	446	.create = fat_create,
434	.destroy = fat_destroy,	447	.destroy = fat_destroy,
435	.link = fat_link,	448	.link = fat_link,
436	.unlink = fat_unlink,	449	.unlink = fat_unlink,
437	.index_get = fat_index_get,	450	.index_get = fat_index_get,
438	.size_get = fat_size_get,	451	.size_get = fat_size_get,
439	.lnkcnt_get = fat_lnkcnt_get,	452	.lnkcnt_get = fat_lnkcnt_get,
440	.has_children = fat_has_children,	453	.has_children = fat_has_children,
441	.root_get = fat_root_get,	454	.root_get = fat_root_get,
442	.plb_get_char = fat_plb_get_char,	455	.plb_get_char = fat_plb_get_char,
443	.is_directory = fat_is_directory,	456	.is_directory = fat_is_directory,
444	.is_file = fat_is_file	457	.is_file = fat_is_file
445	};	458	};
446		459
447	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)	460	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
448	{	461	{
449	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);	462	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
450	block_t *bb;	463	block_t *bb;
451	uint16_t bps;	464	uint16_t bps;
452	uint16_t rde;	465	uint16_t rde;
453	int rc;	466	int rc;
454		467
455	/*	468	/*
456	* For now, we don't bother to remember dev_handle, dev_phone or	469	* For now, we don't bother to remember dev_handle, dev_phone or
457	* dev_buffer in some data structure. We use global variables because we	470	* dev_buffer in some data structure. We use global variables because we
458	* know there will be at most one mount on this file system.	471	* know there will be at most one mount on this file system.
459	* Of course, this is a huge TODO item.	472	* Of course, this is a huge TODO item.
460	*/	473	*/
461	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,	474	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,
462	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);	475	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);
463		476
464	if (!dev_buffer) {	477	if (!dev_buffer) {
465	ipc_answer_0(rid, ENOMEM);	478	ipc_answer_0(rid, ENOMEM);
466	return;	479	return;
467	}	480	}
468		481
469	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,	482	dev_phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
470	DEVMAP_CONNECT_TO_DEVICE, dev_handle);	483	DEVMAP_CONNECT_TO_DEVICE, dev_handle);
471		484
472	if (dev_phone < 0) {	485	if (dev_phone < 0) {
473	munmap(dev_buffer, BS_SIZE);	486	munmap(dev_buffer, BS_SIZE);
474	ipc_answer_0(rid, dev_phone);	487	ipc_answer_0(rid, dev_phone);
475	return;	488	return;
476	}	489	}
477		490
478	rc = ipc_share_out_start(dev_phone, dev_buffer,	491	rc = ipc_share_out_start(dev_phone, dev_buffer,
479	AS_AREA_READ \| AS_AREA_WRITE);	492	AS_AREA_READ \| AS_AREA_WRITE);
480	if (rc != EOK) {	493	if (rc != EOK) {
481	munmap(dev_buffer, BS_SIZE);	494	munmap(dev_buffer, BS_SIZE);
482	ipc_answer_0(rid, rc);	495	ipc_answer_0(rid, rc);
483	return;	496	return;
484	}	497	}
485		498
486	/* Read the number of root directory entries. */	499	/* Read the number of root directory entries. */
487	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);	500	bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c @ 4348 – Rev 3513 → 3516