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 <libblock.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 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)
{
    block_t *bb, *b;
    fat_dentry_t *d;
    uint16_t bps;
    unsigned dps;
   
    assert(node->dirty);
 
    bb = block_get(node->idx->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, node->idx->dev_handle, node->idx->pfc,
        (node->idx->pdi * sizeof(fat_dentry_t)) / bps);
 
    d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
 
    d->firstc = host2uint16_t_le(node->firstc);
    if (node->type == FAT_FILE)
        d->size = host2uint32_t_le(node->size);
    /* TODO: update other fields? (e.g time fields, attr field) */
   
    b->dirty = true;        /* need to sync block */
    block_put(b);
    block_put(bb);
}
 
/** 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 3519	Rev 3521
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 <libblock.h>
43	#include <ipc/ipc.h>	44	#include <ipc/ipc.h>
44	#include <ipc/services.h>	45	#include <ipc/services.h>
45	#include <ipc/devmap.h>	46	#include <ipc/devmap.h>
46	#include <async.h>	47	#include <async.h>
47	#include <errno.h>	48	#include <errno.h>
48	#include <string.h>	49	#include <string.h>
49	#include <byteorder.h>	50	#include <byteorder.h>
50	#include <libadt/hash_table.h>	51	#include <libadt/hash_table.h>
51	#include <libadt/list.h>	52	#include <libadt/list.h>
52	#include <assert.h>	53	#include <assert.h>
53	#include <futex.h>	54	#include <futex.h>
54	#include <sys/mman.h>	55	#include <sys/mman.h>
55	#include <align.h>	56	#include <align.h>
56		57
57	/** Futex protecting the list of cached free FAT nodes. */	58	/** Futex protecting the list of cached free FAT nodes. */
58	static futex_t ffn_futex = FUTEX_INITIALIZER;	59	static futex_t ffn_futex = FUTEX_INITIALIZER;
59		60
60	/** List of cached free FAT nodes. */	61	/** List of cached free FAT nodes. */
61	static LIST_INITIALIZE(ffn_head);	62	static LIST_INITIALIZE(ffn_head);
62		63
63	static int dev_phone = -1; /* FIXME */	-
64	static void dev_buffer = NULL; / FIXME */	-
65		-
66	block_t *block_get(dev_handle_t dev_handle, off_t offset, size_t bs)	-
67	{	-
68	/* FIXME */	-
69	block_t *b;	-
70	off_t bufpos = 0;	-
71	size_t buflen = 0;	-
72	off_t pos = offset * bs;	-
73		-
74	assert(dev_phone != -1);	-
75	assert(dev_buffer);	-
76		-
77	b = malloc(sizeof(block_t));	-
78	if (!b)	-
79	return NULL;	-
80		-
81	b->data = malloc(bs);	-
82	if (!b->data) {	-
83	free(b);	-
84	return NULL;	-
85	}	-
86	b->size = bs;	-
87		-
88	if (!libfs_blockread(dev_phone, dev_buffer, &bufpos, &buflen, &pos,	-
89	b->data, bs, bs)) {	-
90	free(b->data);	-
91	free(b);	-
92	return NULL;	-
93	}	-
94		-
95	return b;	-
96	}	-
97		-
98	void block_put(block_t *block)	-
99	{	-
100	/* FIXME */	-
101	free(block->data);	-
102	free(block);	-
103	}	-
104		-
105	static void fat_node_initialize(fat_node_t *node)	64	static void fat_node_initialize(fat_node_t *node)
106	{	65	{
107	futex_initialize(&node->lock, 1);	66	futex_initialize(&node->lock, 1);
108	node->idx = NULL;	67	node->idx = NULL;
109	node->type = 0;	68	node->type = 0;
110	link_initialize(&node->ffn_link);	69	link_initialize(&node->ffn_link);
111	node->size = 0;	70	node->size = 0;
112	node->lnkcnt = 0;	71	node->lnkcnt = 0;
113	node->refcnt = 0;	72	node->refcnt = 0;
114	node->dirty = false;	73	node->dirty = false;
115	}	74	}
116		75
117	static void fat_node_sync(fat_node_t *node)	76	static void fat_node_sync(fat_node_t *node)
118	{	77	{
119	block_t bb, b;	78	block_t bb, b;
120	fat_dentry_t *d;	79	fat_dentry_t *d;
121	uint16_t bps;	80	uint16_t bps;
122	unsigned dps;	81	unsigned dps;
123		82
124	assert(node->dirty);	83	assert(node->dirty);
125		84
126	bb = block_get(node->idx->dev_handle, BS_BLOCK, BS_SIZE);	85	bb = block_get(node->idx->dev_handle, BS_BLOCK, BS_SIZE);
127	bps = uint16_t_le2host(FAT_BS(bb)->bps);	86	bps = uint16_t_le2host(FAT_BS(bb)->bps);
128	dps = bps / sizeof(fat_dentry_t);	87	dps = bps / sizeof(fat_dentry_t);
129		88
130	/* Read the block that contains the dentry of interest. */	89	/* Read the block that contains the dentry of interest. */
131	b = _fat_block_get(bb->data, node->idx->dev_handle, node->idx->pfc,	90	b = _fat_block_get(bb->data, node->idx->dev_handle, node->idx->pfc,
132	(node->idx->pdi * sizeof(fat_dentry_t)) / bps);	91	(node->idx->pdi * sizeof(fat_dentry_t)) / bps);
133		92
134	d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);	93	d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
135		94
136	d->firstc = host2uint16_t_le(node->firstc);	95	d->firstc = host2uint16_t_le(node->firstc);
137	if (node->type == FAT_FILE)	96	if (node->type == FAT_FILE)
138	d->size = host2uint32_t_le(node->size);	97	d->size = host2uint32_t_le(node->size);
139	/* TODO: update other fields? (e.g time fields, attr field) */	98	/* TODO: update other fields? (e.g time fields, attr field) */
140		99
141	b->dirty = true; /* need to sync block */	100	b->dirty = true; /* need to sync block */
142	block_put(b);	101	block_put(b);
143	block_put(bb);	102	block_put(bb);
144	}	103	}
145		104
146	/** Internal version of fat_node_get().	105	/** Internal version of fat_node_get().
147	*	106	*
148	* @param idxp Locked index structure.	107	* @param idxp Locked index structure.
149	*/	108	*/
150	static void fat_node_get_core(fat_idx_t idxp)	109	static void fat_node_get_core(fat_idx_t idxp)
151	{	110	{
152	block_t bb, b;	111	block_t bb, b;
153	fat_dentry_t *d;	112	fat_dentry_t *d;
154	fat_node_t *nodep = NULL;	113	fat_node_t *nodep = NULL;
155	unsigned bps;	114	unsigned bps;
156	unsigned dps;	115	unsigned dps;
157		116
158	if (idxp->nodep) {	117	if (idxp->nodep) {
159	/*	118	/*
160	* We are lucky.	119	* We are lucky.
161	* The node is already instantiated in memory.	120	* The node is already instantiated in memory.
162	*/	121	*/
163	futex_down(&idxp->nodep->lock);	122	futex_down(&idxp->nodep->lock);
164	if (!idxp->nodep->refcnt++)	123	if (!idxp->nodep->refcnt++)
165	list_remove(&idxp->nodep->ffn_link);	124	list_remove(&idxp->nodep->ffn_link);
166	futex_up(&idxp->nodep->lock);	125	futex_up(&idxp->nodep->lock);
167	return idxp->nodep;	126	return idxp->nodep;
168	}	127	}
169		128
170	/*	129	/*
171	* We must instantiate the node from the file system.	130	* We must instantiate the node from the file system.
172	*/	131	*/
173		132
174	assert(idxp->pfc);	133	assert(idxp->pfc);
175		134
176	futex_down(&ffn_futex);	135	futex_down(&ffn_futex);
177	if (!list_empty(&ffn_head)) {	136	if (!list_empty(&ffn_head)) {
178	/* Try to use a cached free node structure. */	137	/* Try to use a cached free node structure. */
179	fat_idx_t *idxp_tmp;	138	fat_idx_t *idxp_tmp;
180	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);	139	nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
181	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)	140	if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK)
182	goto skip_cache;	141	goto skip_cache;
183	idxp_tmp = nodep->idx;	142	idxp_tmp = nodep->idx;
184	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {	143	if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) {
185	futex_up(&nodep->lock);	144	futex_up(&nodep->lock);
186	goto skip_cache;	145	goto skip_cache;
187	}	146	}
188	list_remove(&nodep->ffn_link);	147	list_remove(&nodep->ffn_link);
189	futex_up(&ffn_futex);	148	futex_up(&ffn_futex);
190	if (nodep->dirty)	149	if (nodep->dirty)
191	fat_node_sync(nodep);	150	fat_node_sync(nodep);
192	idxp_tmp->nodep = NULL;	151	idxp_tmp->nodep = NULL;
193	futex_up(&nodep->lock);	152	futex_up(&nodep->lock);
194	futex_up(&idxp_tmp->lock);	153	futex_up(&idxp_tmp->lock);
195	} else {	154	} else {
196	skip_cache:	155	skip_cache:
197	/* Try to allocate a new node structure. */	156	/* Try to allocate a new node structure. */
198	futex_up(&ffn_futex);	157	futex_up(&ffn_futex);
199	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));	158	nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
200	if (!nodep)	159	if (!nodep)
201	return NULL;	160	return NULL;
202	}	161	}
203	fat_node_initialize(nodep);	162	fat_node_initialize(nodep);
204		163
205	bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);	164	bb = block_get(idxp->dev_handle, BS_BLOCK, BS_SIZE);
206	bps = uint16_t_le2host(FAT_BS(bb)->bps);	165	bps = uint16_t_le2host(FAT_BS(bb)->bps);
207	dps = bps / sizeof(fat_dentry_t);	166	dps = bps / sizeof(fat_dentry_t);
208		167
209	/* Read the block that contains the dentry of interest. */	168	/* Read the block that contains the dentry of interest. */
210	b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,	169	b = _fat_block_get(bb->data, idxp->dev_handle, idxp->pfc,
211	(idxp->pdi * sizeof(fat_dentry_t)) / bps);	170	(idxp->pdi * sizeof(fat_dentry_t)) / bps);
212	assert(b);	171	assert(b);
213		172
214	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);	173	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
215	if (d->attr & FAT_ATTR_SUBDIR) {	174	if (d->attr & FAT_ATTR_SUBDIR) {
216	/*	175	/*
217	* The only directory which does not have this bit set is the	176	* The only directory which does not have this bit set is the
218	* root directory itself. The root directory node is handled	177	* root directory itself. The root directory node is handled
219	* and initialized elsewhere.	178	* and initialized elsewhere.
220	*/	179	*/
221	nodep->type = FAT_DIRECTORY;	180	nodep->type = FAT_DIRECTORY;
222	/*	181	/*
223	* Unfortunately, the 'size' field of the FAT dentry is not	182	* Unfortunately, the 'size' field of the FAT dentry is not
224	* defined for the directory entry type. We must determine the	183	* defined for the directory entry type. We must determine the
225	* size of the directory by walking the FAT.	184	* size of the directory by walking the FAT.
226	*/	185	*/
227	nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,	186	nodep->size = bps * _fat_blcks_get(bb->data, idxp->dev_handle,
228	uint16_t_le2host(d->firstc), NULL);	187	uint16_t_le2host(d->firstc), NULL);
229	} else {	188	} else {
230	nodep->type = FAT_FILE;	189	nodep->type = FAT_FILE;
231	nodep->size = uint32_t_le2host(d->size);	190	nodep->size = uint32_t_le2host(d->size);
232	}	191	}
233	nodep->firstc = uint16_t_le2host(d->firstc);	192	nodep->firstc = uint16_t_le2host(d->firstc);
234	nodep->lnkcnt = 1;	193	nodep->lnkcnt = 1;
235	nodep->refcnt = 1;	194	nodep->refcnt = 1;
236		195
237	block_put(b);	196	block_put(b);
238	block_put(bb);	197	block_put(bb);
239		198
240	/* Link the idx structure with the node structure. */	199	/* Link the idx structure with the node structure. */
241	nodep->idx = idxp;	200	nodep->idx = idxp;
242	idxp->nodep = nodep;	201	idxp->nodep = nodep;
243		202
244	return nodep;	203	return nodep;
245	}	204	}
246		205
247	/** Instantiate a FAT in-core node. */	206	/** Instantiate a FAT in-core node. */
248	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)	207	static void *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
249	{	208	{
250	void *node;	209	void *node;
251	fat_idx_t *idxp;	210	fat_idx_t *idxp;
252		211
253	idxp = fat_idx_get_by_index(dev_handle, index);	212	idxp = fat_idx_get_by_index(dev_handle, index);
254	if (!idxp)	213	if (!idxp)
255	return NULL;	214	return NULL;
256	/* idxp->lock held */	215	/* idxp->lock held */
257	node = fat_node_get_core(idxp);	216	node = fat_node_get_core(idxp);
258	futex_up(&idxp->lock);	217	futex_up(&idxp->lock);
259	return node;	218	return node;
260	}	219	}
261		220
262	static void fat_node_put(void *node)	221	static void fat_node_put(void *node)
263	{	222	{
264	fat_node_t nodep = (fat_node_t )node;	223	fat_node_t nodep = (fat_node_t )node;
265		224
266	futex_down(&nodep->lock);	225	futex_down(&nodep->lock);
267	if (!--nodep->refcnt) {	226	if (!--nodep->refcnt) {
268	futex_down(&ffn_futex);	227	futex_down(&ffn_futex);
269	list_append(&nodep->ffn_link, &ffn_head);	228	list_append(&nodep->ffn_link, &ffn_head);
270	futex_up(&ffn_futex);	229	futex_up(&ffn_futex);
271	}	230	}
272	futex_up(&nodep->lock);	231	futex_up(&nodep->lock);
273	}	232	}
274		233
275	static void *fat_create(int flags)	234	static void *fat_create(int flags)
276	{	235	{
277	return NULL; /* not supported at the moment */	236	return NULL; /* not supported at the moment */
278	}	237	}
279		238
280	static int fat_destroy(void *node)	239	static int fat_destroy(void *node)
281	{	240	{
282	return ENOTSUP; /* not supported at the moment */	241	return ENOTSUP; /* not supported at the moment */
283	}	242	}
284		243
285	static bool fat_link(void prnt, void chld, const char *name)	244	static bool fat_link(void prnt, void chld, const char *name)
286	{	245	{
287	return false; /* not supported at the moment */	246	return false; /* not supported at the moment */
288	}	247	}
289		248
290	static int fat_unlink(void prnt, void chld)	249	static int fat_unlink(void prnt, void chld)
291	{	250	{
292	return ENOTSUP; /* not supported at the moment */	251	return ENOTSUP; /* not supported at the moment */
293	}	252	}
294		253
295	static void fat_match(void prnt, const char *component)	254	static void fat_match(void prnt, const char *component)
296	{	255	{
297	fat_node_t parentp = (fat_node_t )prnt;	256	fat_node_t parentp = (fat_node_t )prnt;
298	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	257	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
299	unsigned i, j;	258	unsigned i, j;
300	unsigned bps; /* bytes per sector */	259	unsigned bps; /* bytes per sector */
301	unsigned dps; /* dentries per sector */	260	unsigned dps; /* dentries per sector */
302	unsigned blocks;	261	unsigned blocks;
303	fat_dentry_t *d;	262	fat_dentry_t *d;
304	block_t bb, b;	263	block_t bb, b;
305		264
306	futex_down(&parentp->idx->lock);	265	futex_down(&parentp->idx->lock);
307	bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);	266	bb = block_get(parentp->idx->dev_handle, BS_BLOCK, BS_SIZE);
308	bps = uint16_t_le2host(FAT_BS(bb)->bps);	267	bps = uint16_t_le2host(FAT_BS(bb)->bps);
309	dps = bps / sizeof(fat_dentry_t);	268	dps = bps / sizeof(fat_dentry_t);
310	blocks = parentp->size / bps + (parentp->size % bps != 0);	269	blocks = parentp->size / bps + (parentp->size % bps != 0);
311	for (i = 0; i < blocks; i++) {	270	for (i = 0; i < blocks; i++) {
312	unsigned dentries;	271	unsigned dentries;
313		272
314	b = fat_block_get(bb->data, parentp, i);	273	b = fat_block_get(bb->data, parentp, i);
315	dentries = (i == blocks - 1) ?	274	dentries = (i == blocks - 1) ?
316	parentp->size % sizeof(fat_dentry_t) :	275	parentp->size % sizeof(fat_dentry_t) :
317	dps;	276	dps;
318	for (j = 0; j < dentries; j++) {	277	for (j = 0; j < dentries; j++) {
319	d = ((fat_dentry_t *)b->data) + j;	278	d = ((fat_dentry_t *)b->data) + j;
320	switch (fat_classify_dentry(d)) {	279	switch (fat_classify_dentry(d)) {
321	case FAT_DENTRY_SKIP:	280	case FAT_DENTRY_SKIP:
322	continue;	281	continue;
323	case FAT_DENTRY_LAST:	282	case FAT_DENTRY_LAST:
324	block_put(b);	283	block_put(b);
325	block_put(bb);	284	block_put(bb);
326	futex_up(&parentp->idx->lock);	285	futex_up(&parentp->idx->lock);
327	return NULL;	286	return NULL;
328	default:	287	default:
329	case FAT_DENTRY_VALID:	288	case FAT_DENTRY_VALID:
330	dentry_name_canonify(d, name);	289	dentry_name_canonify(d, name);
331	break;	290	break;
332	}	291	}
333	if (stricmp(name, component) == 0) {	292	if (stricmp(name, component) == 0) {
334	/* hit */	293	/* hit */
335	void *node;	294	void *node;
336	/*	295	/*
337	* Assume tree hierarchy for locking. We	296	* Assume tree hierarchy for locking. We
338	* already have the parent and now we are going	297	* already have the parent and now we are going
339	* to lock the child. Never lock in the oposite	298	* to lock the child. Never lock in the oposite
340	* order.	299	* order.
341	*/	300	*/
342	fat_idx_t *idx = fat_idx_get_by_pos(	301	fat_idx_t *idx = fat_idx_get_by_pos(
343	parentp->idx->dev_handle, parentp->firstc,	302	parentp->idx->dev_handle, parentp->firstc,
344	i * dps + j);	303	i * dps + j);
345	futex_up(&parentp->idx->lock);	304	futex_up(&parentp->idx->lock);
346	if (!idx) {	305	if (!idx) {
347	/*	306	/*
348	* Can happen if memory is low or if we	307	* Can happen if memory is low or if we
349	* run out of 32-bit indices.	308	* run out of 32-bit indices.
350	*/	309	*/
351	block_put(b);	310	block_put(b);
352	block_put(bb);	311	block_put(bb);
353	return NULL;	312	return NULL;
354	}	313	}
355	node = fat_node_get_core(idx);	314	node = fat_node_get_core(idx);
356	futex_up(&idx->lock);	315	futex_up(&idx->lock);
357	block_put(b);	316	block_put(b);
358	block_put(bb);	317	block_put(bb);
359	return node;	318	return node;
360	}	319	}
361	}	320	}
362	block_put(b);	321	block_put(b);
363	}	322	}
364	block_put(bb);	323	block_put(bb);
365		324
366	futex_up(&parentp->idx->lock);	325	futex_up(&parentp->idx->lock);
367	return NULL;	326	return NULL;
368	}	327	}
369		328
370	static fs_index_t fat_index_get(void *node)	329	static fs_index_t fat_index_get(void *node)
371	{	330	{
372	fat_node_t fnodep = (fat_node_t )node;	331	fat_node_t fnodep = (fat_node_t )node;
373	if (!fnodep)	332	if (!fnodep)
374	return 0;	333	return 0;
375	return fnodep->idx->index;	334	return fnodep->idx->index;
376	}	335	}
377		336
378	static size_t fat_size_get(void *node)	337	static size_t fat_size_get(void *node)
379	{	338	{
380	return ((fat_node_t *)node)->size;	339	return ((fat_node_t *)node)->size;
381	}	340	}
382		341
383	static unsigned fat_lnkcnt_get(void *node)	342	static unsigned fat_lnkcnt_get(void *node)
384	{	343	{
385	return ((fat_node_t *)node)->lnkcnt;	344	return ((fat_node_t *)node)->lnkcnt;
386	}	345	}
387		346
388	static bool fat_has_children(void *node)	347	static bool fat_has_children(void *node)
389	{	348	{
390	fat_node_t nodep = (fat_node_t )node;	349	fat_node_t nodep = (fat_node_t )node;
391	unsigned bps;	350	unsigned bps;
392	unsigned dps;	351	unsigned dps;
393	unsigned blocks;	352	unsigned blocks;
394	block_t bb, b;	353	block_t bb, b;
395	unsigned i, j;	354	unsigned i, j;
396		355
397	if (nodep->type != FAT_DIRECTORY)	356	if (nodep->type != FAT_DIRECTORY)
398	return false;	357	return false;
399		358
400	futex_down(&nodep->idx->lock);	359	futex_down(&nodep->idx->lock);
401	bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);	360	bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
402	bps = uint16_t_le2host(FAT_BS(bb)->bps);	361	bps = uint16_t_le2host(FAT_BS(bb)->bps);
403	dps = bps / sizeof(fat_dentry_t);	362	dps = bps / sizeof(fat_dentry_t);
404		363
405	blocks = nodep->size / bps + (nodep->size % bps != 0);	364	blocks = nodep->size / bps + (nodep->size % bps != 0);
406		365
407	for (i = 0; i < blocks; i++) {	366	for (i = 0; i < blocks; i++) {
408	unsigned dentries;	367	unsigned dentries;
409	fat_dentry_t *d;	368	fat_dentry_t *d;
410		369
411	b = fat_block_get(bb->data, nodep, i);	370	b = fat_block_get(bb->data, nodep, i);
412	dentries = (i == blocks - 1) ?	371	dentries = (i == blocks - 1) ?
413	nodep->size % sizeof(fat_dentry_t) :	372	nodep->size % sizeof(fat_dentry_t) :
414	dps;	373	dps;
415	for (j = 0; j < dentries; j++) {	374	for (j = 0; j < dentries; j++) {
416	d = ((fat_dentry_t *)b->data) + j;	375	d = ((fat_dentry_t *)b->data) + j;
417	switch (fat_classify_dentry(d)) {	376	switch (fat_classify_dentry(d)) {
418	case FAT_DENTRY_SKIP:	377	case FAT_DENTRY_SKIP:
419	continue;	378	continue;
420	case FAT_DENTRY_LAST:	379	case FAT_DENTRY_LAST:
421	block_put(b);	380	block_put(b);
422	block_put(bb);	381	block_put(bb);
423	futex_up(&nodep->idx->lock);	382	futex_up(&nodep->idx->lock);
424	return false;	383	return false;
425	default:	384	default:
426	case FAT_DENTRY_VALID:	385	case FAT_DENTRY_VALID:
427	block_put(b);	386	block_put(b);
428	block_put(bb);	387	block_put(bb);
429	futex_up(&nodep->idx->lock);	388	futex_up(&nodep->idx->lock);
430	return true;	389	return true;
431	}	390	}
432	block_put(b);	391	block_put(b);
433	block_put(bb);	392	block_put(bb);
434	futex_up(&nodep->idx->lock);	393	futex_up(&nodep->idx->lock);
435	return true;	394	return true;
436	}	395	}
437	block_put(b);	396	block_put(b);
438	}	397	}
439	block_put(bb);	398	block_put(bb);
440		399
441	futex_up(&nodep->idx->lock);	400	futex_up(&nodep->idx->lock);
442	return false;	401	return false;
443	}	402	}
444		403
445	static void *fat_root_get(dev_handle_t dev_handle)	404	static void *fat_root_get(dev_handle_t dev_handle)
446	{	405	{
447	return fat_node_get(dev_handle, 0);	406	return fat_node_get(dev_handle, 0);
448	}	407	}
449		408
450	static char fat_plb_get_char(unsigned pos)	409	static char fat_plb_get_char(unsigned pos)
451	{	410	{
452	return fat_reg.plb_ro[pos % PLB_SIZE];	411	return fat_reg.plb_ro[pos % PLB_SIZE];
453	}	412	}
454		413
455	static bool fat_is_directory(void *node)	414	static bool fat_is_directory(void *node)
456	{	415	{
457	return ((fat_node_t *)node)->type == FAT_DIRECTORY;	416	return ((fat_node_t *)node)->type == FAT_DIRECTORY;
458	}	417	}
459		418
460	static bool fat_is_file(void *node)	419	static bool fat_is_file(void *node)
461	{	420	{
462	return ((fat_node_t *)node)->type == FAT_FILE;	421	return ((fat_node_t *)node)->type == FAT_FILE;
463	}	422	}
464		423
465	/** libfs operations */	424	/** libfs operations */
466	libfs_ops_t fat_libfs_ops = {	425	libfs_ops_t fat_libfs_ops = {
467	.match = fat_match,	426	.match = fat_match,
468	.node_get = fat_node_get,	427	.node_get = fat_node_get,
469	.node_put = fat_node_put,	428	.node_put = fat_node_put,
470	.create = fat_create,	429	.create = fat_create,
471	.destroy = fat_destroy,	430	.destroy = fat_destroy,
472	.link = fat_link,	431	.link = fat_link,
473	.unlink = fat_unlink,	432	.unlink = fat_unlink,
474	.index_get = fat_index_get,	433	.index_get = fat_index_get,
475	.size_get = fat_size_get,	434	.size_get = fat_size_get,
476	.lnkcnt_get = fat_lnkcnt_get,	435	.lnkcnt_get = fat_lnkcnt_get,
477	.has_children = fat_has_children,	436	.has_children = fat_has_children,
478	.root_get = fat_root_get,	437	.root_get = fat_root_get,
479	.plb_get_char = fat_plb_get_char,	438	.plb_get_char = fat_plb_get_char,
480	.is_directory = fat_is_directory,	439	.is_directory = fat_is_directory,
481	.is_file = fat_is_file	440	.is_file = fat_is_file
482	};	441	};
483		442
484	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)	443	void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
485	{	444	{
486	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);	445	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
487	block_t *bb;	446	block_t *bb;
488	uint16_t bps;	447	uint16_t bps;
489	uint16_t rde;	448	uint16_t rde;
490	int rc;	449	int rc;
491		450
492	/*	451	/*
493	* For now, we don't bother to remember dev_handle, dev_phone or	452	* For now, we don't bother to remember dev_handle, dev_phone or
494	* dev_buffer in some data structure. We use global variables because we	453	* dev_buffer in some data structure. We use global variables because we
495	* know there will be at most one mount on this file system.	454	* know there will be at most one mount on this file system.
496	* Of course, this is a huge TODO item.	455	* Of course, this is a huge TODO item.
497	*/	456	*/
498	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,	457	dev_buffer = mmap(NULL, BS_SIZE, PROTO_READ \| PROTO_WRITE,
499	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);	458	MAP_ANONYMOUS \| MAP_PRIVATE, 0, 0);

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 3519 → 3521